Capital structure of portuguese hotel firms: a structural equation modelling approach

This paper addresses capital structure determinants for Portuguese hotel firms between 2006 and 2014. Secondary data from 356 hotel units was analysed using the partial least squares (PLS) statistical technique, a variance-based structural equation modelling (SEM). The results show that the explanatory variables proposed as capital structure determinants have an impact on the financing and debt decisions made by the firms in the sample. Of these, tangibility has the greater explanatory power. Overall, the results support the notion that trade-off theory and pecking-order theory are important in explaining the capital structure of the Portuguese hotel industry, particularly as regards the agency conflicts triggered by growth opportunities and the preference firms have for internal funding. The results also point to the importance of collateral in accessing credit and the lesser impact of asymmetric information pertaining to tangible asset value and firm size. The results suggest small firms find it difficult to contract loans, which can somewhat limit their growth and performance.info:eu-repo/semantics/publishedVersio

Enantioselective Determination of Fluoxetine and Norfluoxetine in Wastewater

Microbial degradation of chiral compounds during wastewater treatment processes can be enantioselective and needs chiral analytical methodology to discriminate the biodegradation of both enantiomers. An enantioselective HPLC-FD method was developed and validated to monitor the degradation of fluoxetine (FLX) enantiomers by wastewater and the possible formation of its metabolite norfluoxetine (NFLX). The Solid Phase Extraction (SPE) of 50 mL of wastewater samples on 500 mg Oasis MCX cartridges was followed by the HPLC analysis using a Chirobiotic V chiral stationary phase under reversed mode. The developed method wasvalidated within the wastewater effluent used in microcosms laboratory assays. The chiral SPE-HPLC-FD method demonstrated to be selective, linear, sensitive, accurate and precise to quantify the enantiomers of FLX and of its metabolites NFLX in wastewaters. The limits of detection (0.8-2.0 ng mL -1 ) and quantification (2.0 – 4.0 ng mL -1 ) were adequate to monitoring the degradation assays at environmental level. The method proved to be robust to follow the biodegradation assays using real wastewater samplesspiked with FLX, during 46 days. To the best of our knowledge, this is the first reportof simultaneous separation of FLX and NFLX enantiomers using a Chirobiotic V and the application of the validated method to the enantioselective degradation by wastewate

Enantioselective Degradation of Enantiomers of Fluoxetine Followed by HPLC- FD

Environmental fate assessment of chiral pharmaceuticals is an important issue and little information is known about enantioselectivity in the environment. This kind of information is important for regulamentation of pharmaceutical industry and chiral switching processes. Fluoxetine (FLX), an anti-depressant worldwide used, is a chiral pharmaceutical prescribed in racemic form, and its main metabolite norfluoxetine (NFLX) is also chiral. In this study, enantioselective degradation of rac-FLX and degradation of its enantiomers separately, in a minimal salts medium inoculated by a bacterium consortium was examined both at light and dark conditions. Theassays were performed in a shaker at aerobic and ambient temperature conditions. The analytical method used was an enantioselective HPLC-FD method using a vancomycin-based chiral stationary phase in reversed mode to monitor enantiomers of FLX and NFLX. No degradation of enantiomers of FLX in the abiotic controls was observed. In theall assays (R)-FLX was degraded faster and totally until day 24th while (S)-FLX remained up to 20% of its initial concentration until the end of the experiment (38 days). NFLX wasdetected in all biotic experiments

Variability of prey preferences and uptake of anthropogenic particles by juvenile white seabream in a coastal lagoon nursery ground

Marine plastic litter, originating from land-based sources, enters the marine environment by passing through coastal ecosystems such as lagoons and estuaries. As early life history stages (ELHS) of many commercially important fish species rely on these transitional areas as nursery grounds, we hypothesized that they encounter a spatial gradient of habitat quality and pollution from inner to outer parts of their vital environment. With sizes < 5 mm, anthropogenic particles (AP), among them microplastic (MP) fibers and fragments, entail a high bioavailability for ELHS of fish, potentially facilitating AP uptake at early developmental stages which may have implications for their survival and growth. This study provides a contextualization baseline between feeding preferences and uptake of AP by the white seabream Diplodus sargus (Linnaeus, 1758) in an estuarine nursery ground on the southern coast of Portugal. Juvenile fish showed a generalized, omnivorous feeding mode with differences in trophic resource utilization between individuals collected at distinct seagrass meadows in the lagoon. A total of 23.13% of the fish (n = 147) were detected with AP in the gastrointestinal tract, and the mean number of AP per AP-feeding individual was 1.64 +/- 1.04, with anthropogenic fibers (n = 47) occurring more frequently than fragments (n = 9). Knowledge of the underlying factors for MP ingestion will be greatly enhanced by considering environmental conditions along with species-stage and life-stage specific feeding modes and prey preferences which shape the uptake probability of anthropogenic fibers and fragments.LA/P/0101/2020info:eu-repo/semantics/publishedVersio

Chiral HPLC-FD method validation for determination of several Beta-Blockers and Fluoxetine in biodegradation assays

Chiral pharmaceuticals and the fate and effects of their enantiomers in the environment are still largely unknown [1, 2]. Enantiomers have different interactions with enzymes, receptors and any chiral molecules leading to different biological activities and affecting organisms in a different manner. Thus, biodegradation tends to be enantioselective in contrast to abiotic degradation. The methods developed to quantify the enantiomeric fraction in the environment and to follow biodegradation are scarce [3]. Thus in this work we describe the development and validation of HPLC methods that allow the enantiomeric separation of widely used drugs namely four beta-blockers: alprenolol (ALP), propranolol (PHO), metoprolol (MET) and atenolol (ATE) and the antidepressant fluoxetine (FX). The macrocyclic antibiotic vancomycin CSP (ASTEC Chirobiotic V 5µm) was used under polar organic mode (methanol:ethanol:triethylamine:acetic acid.50:50 v/v) and fluorescence detection for enantiomeric fraction quantification. The developed methods were established using a minimal medium inoculated with activated sludge as a matrix which is the condition used in the biodegradation studies. The vancomycin CSP was able to resolve ALP and PHO as well as MET, ATE and FX in two chromatographic runs. The chromatographic parameters obtained have shown the separation factor (α) between 1.12 and 1.34 and resolution (Rs) between 1.30 and 4.35. The methods demonstrated to be selective and linearity with r2 higher than 0,999 for the range selected. The method detection limits were between 2.5 to 10ng/mL. These methods were applied to follow the biodegradation of the target chiral compounds during 15 days. The biodegradation assays were performed using activated sludge from a WWTP and the results indicate the higher degradation extents for the S- enantiomer forms

Marxan as a zoning tool for development and economic purposed areas - Aquaculture Management Areas (AMAs)

The increased number of human activities within the marine environment and the demand for maritime space has increased to a point where in some parts of the globe the demand for maritime space has exceeded the available area. The overlapping objectives and activities have caused severe conflicts among users and with the natural marine environment itself. For that reason, holistic strategies such as Ecosystem Based Management (EBM) and Maritime Spatial Planning (MSP) have been evolved and developed to sustainably manage the marine environment, avoiding conflicts and creating synergies. Spatial analysis tools like Marxan have been used for several years as decision support tools mostly for conservation plans, such as design and establishment of protected areas. In this study we approach the potential of this tool with a different purpose in mind: instead of using the available information of the region for the development of a conservation plan, we used this tool and the available information to select areas to establish Aquaculture Management Areas (AMAs). We also intended to analyse how the existing features of the region would affect the final result of a spatial plan aimed to establish areas for economic and development purposes. We conclude that the use of Marxan can be advantageous to support the planning and development of coastal regions, not only in a conservationist point of view (as it has been mostly used), but also into a developing and economic driven approach. This tool can be particularly useful in regions or situations where there is a large number of stakeholders, ecological and geographical features that could potentially conflict with the establishment, the management and the success of the proposed management areas. (C) 2017 Elsevier Ltd. All rights reserved.Administracao da Regiao Hidrografica do Algarve - Agencia Portuguesa do Ambiente [POVT-03-0133- FCOES-000013]EU - DG MARE (Project TPEA) [MARE/2012/08

Microbial degradation of 17β -estradiol and 17α -ethinylestradiol followed by a validated HPLC-DAD method

This work aimed at studying the biodegradation of two estrogens, 17agr -estradiol (E2) and 17β -ethinylestradiol (EE2), and their potential metabolism to estrone (E1) by microbial consortia. The biodegradation studies were followed by High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) using a specifically developed and validated method. Biodegradation studies of the estrogens (E2 and EE2) were carried out with activated sludge (consortium A, CA) obtained from a Wastewater Treatment Plant (WWTP) and with a microbial consortium able to degrade recalcitrant compounds, namely fluorobenzene (consortium B, CB). E2 was more extensively degraded than EE2 by CA whereas CB was only able to degrade E2. The addition of acetate as a supplementary carbon source led to a faster biodegradation of E2 and EE2. E1 was detected as a metabolite only during the degradation of E2. The 16S rRNA gene sequence analyses of strains recovered from the degrading cultures revealed the presence of the genera Pseudomonas, Chryseobacterium and Alcaligenes. The genera Pseudomonas and Chryseobacterium were retrieved from cultures supplied with E2 and EE2, while the genus Alcaligenes was found in the presence of E2, suggesting that they might be involved in the degradation of these compounds.info:eu-repo/semantics/publishedVersio

Mineralization of 4-fluorocinnamic acid by a Rhodococcus strain

A bacterial strain capable of aerobic degradation of 4-fluorocinnamic acid (4-FCA) as the sole source of carbon and energy was isolated from a biofilm reactor operating for the treatment of 2-fluorophenol. The organism, designated as strain S2, was identified by 16S rRNA gene analysis as a member of the genus Rhodococcus. Strain S2 was able to mineralize 4-FCA as sole carbon and energy source. In the presence of a conventional carbon source (sodium acetate [SA]), growth rate of strain S2 was enhanced from 0.04 to 0.14 h−1 when the culture medium was fed with 0.5 mMof 4- FCA, and the time for complete removal of 4-FCA decreased from 216 to 50 h.When grown in SA-supplemented medium, 4-FCA concentrations up to 1 mM did not affect the length of the lag phase, and for 4-FCA concentrations up to 3 mM, strain S2 was able to completely remove the target fluorinated compound. 4-Fluorobenzoate (4-FBA) was transiently formed in the culture medium, reaching concentrations up to 1.7 mM when the cultures were supplemented with 3.5mMof 4-FCA. Trans,trans-muconate was also transiently formed as a metabolic intermediate. Compounds with molecular mass compatible with 3-carboxymuconate and 3-oxoadipate were also detected in the culture medium. Strain S2 was able to mineralize a range of other haloorganic compounds, including 2- fluorophenol, to which the biofilm reactor had been exposed. To our knowledge, this is the first time that mineralization of 4-FCA as the sole carbon source by a single bacterial culture is reported

Enantioselective quantification of fluoxetine and norfluoxetine by HPLC in wastewater effluents

Microbial degradation is the most important process to remove organic pollutants in Waste Water Treatment Plants. Regarding chiral compounds this process is normally enantioselective and needs the suitable analytical methodology to follow the removal of both enantiomers in an accurate way. Thus, this paper describes the development and validation of an enantioselective High Performance Liquid Chromatography with Fluorescence Detection (HPLC-FD) method for simultaneous analysis of fluoxetine (FLX) and norfluoxetine (NFLX) in wastewater effluents. Briefly, this method preconcentrated a small volume of wastewater samples (50 mL) on 500 mg Oasis MCX cartridges and used HPLC-FD with a vancomycin-based chiral stationary phase under reversed mode for analyses. The optimized mobile phase was EtOH/aqueous ammonium acetate buffer (92.5/7.5, v/v) at pH 6.8. The effect of EtOH percentage, buffer concentration, pH, column oven temperature and flow rate on chromatographic parameters was systematically investigated. The developed method was validated within the wastewater effluent used in microcosms laboratory assays. Linearity (R2 > 0.99), selectivity and sensitivity were achieved in the range of 4.0–60 ng mL 1 for enantiomers of FLX and 2.0–30 ng mL 1 for enantiomers of NFLX. The limits of detection were between 0.8 and 2.0 ng mL 1 and the limits of quantification were between 2.0 and 4.0 ng mL 1 for both enantiomers of FLX and the enantiomers of its demethylated metabolite NFLX. The validated method was successfully applied and proved to be robust to follow the degradation of both enantiomers of FLX in wastewater samples, during 46 days.info:eu-repo/semantics/publishedVersio