Stock Splits: Real Effects or Just a Question of Maths? An Empirical Analysis of the Portuguese Case

Stock splits are conceptually a very simple corporate event that consists in the division of each share into a higher number of shares of smaller par value. These operations have long been a part of financial markets. Portugal witnessed 26 of these operations from 1999 (the year the euro was introduced) to June 2003 essentially due to a legislative change that took place when the corporate law was adapted for the introduction of the euro. In this paper stock splits are analyzed in terms of liquidity, risk, signaling and ideal price range explanations that could justify the sizeable cumulative abnormal returns (CAR) that we document around both announcement (5-day CAR of 3.8%) and ex-dates (5-day CAR of 7.5%). Our evidence shows no significant increase in trading volume (in EUR) although the number of trades does seem to increase, suggesting that trading by small investors is increased post-split. Our results also uncover an increase in the relative bid-ask spread but only for a sample subset of firms with the lowest pre- or post-split relative spreads. Our results also suggest, however, that liquidity reasons do not seem to be sufficient to explain the observed abnormal returns around the ex-date. A surprising feature is that the observed significant price increases were mainly concentrated around the ex-date, in contrast to most available evidence. The signaling hypotheses tested were not supported by the evidence presented in this study. These operations also cannot be explained by a placement of share prices levels closer to those of other Eurozone stock markets as Portuguese share prices levels are clearly much lower than the levels observable in those markets. We also conducted a survey directed at splitting firm. This confirmed that liquidity increases were indeed one of the main objectives pretended by the managers of these firms. Most companies, however, considered that this had not been accomplished. Another stated objective deemed important by managers was share capital simplification. This is puzzling since it is difficult to explain the sizeable wealth effects documented with simple changes in the par value itself. Our survey did not support signaling as a justification on the part of managers for the decision to split.Market efficiency, Stock splits, abnormal returns, trading volume,liquidity

Financial imbalance in portuguese local government: a descriptive analysis

This study aimed to make a descriptive analysis of local authorities’ financial imbalance, so as to identify its possible determinants. Data were analysed for all Portuguese local authorities (308) for the period 2014 to 2016. The results led to concluding that the number of municipalities with a financial imbalance diminished during the period of analysis. Large municipalities are less likely to be in situations of financial imbalance. There also seems to be evidence that municipalities governed by a minority, as well as those without financial independence, are more likely to find themselves in this situation. Concerning political ideology (parties on the right or left), no evidence was found of this influencing financial imbalance. This evidence could contribute to those in charge of local authorities defining policies and measures to reduce financial imbalance.This study was conducted at Research Centre in Political Science (UID/CPO/0758/2019), University of Minho and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Education and Science through national funds. This study is funded by National Funds through the Foundation for Science and Technology under the project UID/GES/04752/201

Natural and Synthetic Flavylium-Based Dyes: The Chemistry behind the Color

Funding Information: This research was supported by project grants (PTDC/OCE-ETA/31250/2017; PTDC/QUI-COL/32351/2017), with financial support from FCT/MEC through national funds and cofinancing from FEDER, in Partnership Agreement PT2020 (UIDB/50006/2020 - POCI-01-0247-FEDER-017687); and AgriFoodXXI I&D&I (Norte-01-0145 FEDER-000041) cofinanced by European Regional Development FUND (ERDF), through the NORTE 2020 (Programa Operacional Regional do Norte 2014/2020). L.C. and N.B. acknowledge financial support from FCT/MEC, respectively contract (DL 57/2016/CP1334/CT0008) and (CEECIND/00466/2017). Publisher Copyright: © 2021 The Authors. Published by American Chemical Society.Flavylium compounds are a well-known family of pigments because they are prevalent in the plant kingdom, contributing to colors over a wide range from shades of yellow-red to blue in fruits, flowers, leaves, and other plant parts. Flavylium compounds include a large variety of natural compound classes, namely, anthocyanins, 3-deoxyanthocyanidins, auronidins, and their respective aglycones as well as anthocyanin-derived pigments (e.g., pyranoanthocyanins, anthocyanin-flavan-3-ol dimers). During the past few decades, there has been increasing interest among chemists in synthesizing different flavylium compounds that mimic natural structures but with different substitution patterns that present a variety of spectroscopic characteristics in view of their applications in different industrial fields. This Review provides an overview of the chemistry of flavylium-based compounds, in particular, the synthetic and enzymatic approaches and mechanisms reported in the literature for obtaining different classes of pigments, their physical-chemical properties in relation to their pH-dependent equilibria network, and their chemical and enzymatic degradation. The development of flavylium-based systems is also described throughout this Review for emergent applications to explore some of the physical-chemical properties of the multistate of species generated by these compounds.publishersversionpublishe

Selective Recognition of Amino Acids and Peptides by Small Supramolecular Receptors

UIDB/50006/2020To this day, the recognition and high affinity binding of biomolecules in water by synthetic receptors remains challenging, while the necessity for systems for their sensing, transport and modulation persists. This problematic is prevalent for the recognition of peptides, which not only have key roles in many biochemical pathways, as well as having pharmacological and biotechnological applications, but also frequently serve as models for the study of proteins. Taking inspiration in nature and on the interactions that occur between several receptors and peptide sequences, many researchers have developed and applied a variety of different synthetic receptors, as is the case of macrocyclic compounds, molecular imprinted polymers, organometallic cages, among others, to bind amino acids, small peptides and proteins. In this critical review, we present and discuss selected examples of synthetic receptors for amino acids and peptides, with a greater focus on supramolecular receptors, which show great promise for the selective recognition of these biomolecules in physiological conditions. We decided to focus preferentially on small synthetic receptors (leaving out of this review high molecular weight polymeric systems) for which more detailed and accurate molecular level information regarding the main structural and thermodynamic features of the receptor biomolecule assemblies is available.publishersversionpublishe

Sulfonatocalixarene Counterion Exchange Binding Model in Action: Metal-Ion Catalysis Through Host-Guest Complexation

This work was supported by the Associated Laboratory for Sustainable Chemistry-Clean Processes and Technologies-LAQV (FCT/MCTES fund UID/QUI/50006/2019) and the Portuguese Fundação para a Ciencia e Tecnologia (grant CEECIND/00466/2017 to N.B.). Financial support from Ministerio de Economia y Competitividad of Spain (project CTQ2017-84354-P), Xunta de Galicia (GR 2007/085; IN607 C 2016/03 and Centro singular de investigacion de Galicia accreditation 2016-2019, ED431G/09) and the European Union (European Regional Development Fund-ERDF), is gratefully acknowledged.p-Sulfonatocalixarene water soluble macrocyclic host receptors are known to form cooperative ternary complexes with complementary organic guest and metal cations. This property may be explored to enhance the interaction of weak nitrogen ligands with metal cations in a confined space showing some resemblance to metal-containing enzymes. However, the best of our knowledge, catalytic potential of this property remains unexplored. In this work the Ni2+ catalyzed hydrolysis of a picolinate ester (2,4-dinitrophenyl picolinate, 1) was used as a model reaction to evaluate the effect of sulfonatocalixarene macrocycles in the kinetics of this reaction. The results show that the host molecules promote the reaction through simultaneous complexation of the metal cation and the substrate and, in the case of the larger calixarenes containing more basic phenol groups, substantially higher rate enhancements are observed owing to additional assistance provided by base/nucleophilic catalysis. However, due the ionic nature of these receptors auto-inhibition of the reaction is observed at higher concentrations due counterion (Na+) binding that competes with the catalytically active Ni2+ -complexes.publishersversionpublishe

The Effect of the Copigment on the pH-Dependent Reversible and Irreversible Processes

no 219201Intermolecular copigmentation of malvidin-3-O-glucoside with caffeine was studied using a holistic procedure that includes the extension to basic pH values. In moderately basic solutions (7.5 < pH < 9.5) and independently of the copigment presence, there is a pH region where degradation of the quinoidal base and anionic quinoidal bases is faster than hydration and OH-nucleophilic addition, preventing the system from reaching the equilibrium. Intermolecular copigmentation with caffeine reduces significantly the degradation rate of quinoidal bases. In a more basic medium, the equilibrium is reached and degradation occurs from the anionic chalcones. In this case, the addition of caffeine also reduces the degradation rate in the interval 10 < pH < 11.5.publishersversionpublishe

Anthocyanin color stabilization by host‐guest complexation with p‐sulfonatocalix[n]arenes

Funding Information: Funding: This research was supported by the Associated Laboratory for Sustainable Chemistry, Clean Processes and Technologies LAQV through national funds from UIDB/50006/2020. FCT/MCTES is also acknowledged for supporting the National Portuguese NMR Network (ROTEIRO/0031/2013‐PINFRA/22161/2016, co‐financed by FEDER through COMPETE 2020, POCI, PORL, and FCT through PIDDAC) and for the grant PTDC/QUI‐COL/32351/2017. J.M. is grateful for the doctoral grant awarded by CONACYT (MEX/Ref. 288188). N.B. acknowledges FCT for the contract CEECIND/00466/2017.Flavylium‐based compounds in their acidic and cationic form bring color to aqueous solutions, while under slightly acidic or neutral conditions they commonly bring discoloration. Selective host‐guest complexation between water‐soluble p‐sulfonatocalix[n]arenes (SCn) macrocycles and the flavylium cationic species can increase the stability of the colored form, expanding its domain over the pH scale. The association constants between SCn and the cationic (acid) and neutral basic forms of flavylium‐based compounds were determined through UV‐Vis host‐guest titrations at different pH values. The affinity of the hosts for synthetic chromophore was found to be higher than for a natural anthocyanin (Oenin). The higher affinity of SC4 for the synthetic flavylium was confirmed by1H NMR showing a preferential interaction of the flavylium phenyl ring with the host cavity. In contrast with its synthetic counterpart, the flavylium substitution pattern in the anthocyanin seems to limit the inclusion of the guest in the host’s binding pocket. In this case, the higher affinity was observed for the octamer (SC8) likely due to its larger cavity and higher number of negatively charged sulfonate groups.publishersversionpublishe

Impact of a Water-Soluble Gallic Acid-Based Dendrimer on the Color-Stabilizing Mechanisms of Anthocyanins

project grant (PTDC/OCE-ETA/31250/2017) with financial support from FCT/MCTES through national funds and co-financed by FEDER, under the Partnership Agreement PT2020 (UID/QUI/50006/2019-POCI/01/0145/FEDER/007265). Financial support was also obtained from the Spanish Ministry of Science, Innovation and Universities (CTQ2015-69021-R and RTI2018-102212-B-I00), the Xunta de Galicia (GRC2014/040, ED431C 2018/30, and Centro Singular de Investigacion de Galicia Accreditation 2016-2019, ED431G/09) and the European Union (European Regional Development Fund-ERDF).The interaction of two anthocyanins with a water-soluble polyanionic dendrimer was studied through UV/Vis, stopped-flow, and NMR spectroscopy. Cyanidin-3-glucoside (cy3glc) revealed a stronger interaction than malvidin-3-glucoside (mv3glc) at pH 1 according to their apparent association constants. A higher color increased was also obtained for cy3glc at pH 3.5 as a result of this stronger interaction. A high-frequency chemical shift of the cy3glc aromatic protons suggest the formation of ionic pairs. The interaction parameters (K≈700 m−1, n≈295) indicated the binding of approximately two anthocyanin molecules by each sulfate group. The equilibrium and rate constants of cy3glc in the presence of dendrimer showed an increased stability of the flavylium cation and a higher protection of this species from hydration (pK′a and pKh increased almost one pH unit). The tuning and color stabilization of anthocyanins by using this dendrimer allow novel applications as colorimetric sensors for food packaging.authorsversionpublishe

Binding of the five multistate species of the anthocyanin analog 7- β -D-glucopyranosyloxy-4′-hydroxyflavylium to the β -cyclodextrin derivative captisol

The host-guest chemistry of the anthocyanin analog 7-β-D-glucopyranosyloxy-4'-hydroxyflavylium (GHF) was studied in the presence of the β-cyclodextrin derivative captisol by stopped flow, UVevisible spectroscopy, flash photolysis, circular dichroism and isothermal titration calorimetry. The equilibrium and rate constants of the multistate of chemical species derived from the flavylium ion were calculated and compared with those in the absence of the host. A new procedure to obtain the host-guest association constants of the multistate (including the transient species) by superimposing the two energy level diagrams, in the presence and absence of the cyclodextrin, was developed. The results indicate that the magnitude of the association constants follows the order, trans-chalcone = cis-chalcone = hemiketal > quinoidal base > flavylium cation. The hydration equilibrium constant increases ca. 42 times in the presence of captisol as the hydration and dehydration rate constants respectively increases and decreases. The other equilibrium constants are modestly affected: the rate constants of ring closure and opening are significantly decreased in the complex and the isomerization rate constants increase in both directions. The quantum yield of the photochromic system in the presence of captisol is0.3, i.e. 3 times higher than in the absence of the host

Photoswitchable Calixarene Activators for Controlled Peptide Transport across Lipid Membranes

Funding Information: This work was supported by the Associate Laboratory for Green Chemistry-LAQV (projects UIDB/50006/2020 and UIDP/50006/2020), which is financed by national funds from FCT/MCTES. FCT/MCTES is also acknowledged for supporting the National Portuguese NMR Network (ROTEIRO/0031/2013-PINFRA/22161/2016, cofinanced by FEDER through COMPETE 2020, POCI, PORL, and FCT through PIDDAC) and for the projects PTDC/QUI-COL/32351/2017, 2022.02538.PTDC, and the CEECIND/00466/2017 research contract (N.B.). J.N.M. acknowledges FCT for the PhD grant (2021.06296.BD). J.M. thanks the Spanish Agencia Estatal de Investigación (AEI) [PCI2019-103400 and PID2020-117143RB-I00], Xunta de Galicia (ED431C 2017/25 and ED431G 2019/03), and the ERDF. J.M. received an ERC-Stg (DYNAP, 677786), ERC-POC (TraffikGene, 838002), Xunta de Galicia (Oportunius Program), and HFSP-YIG (RGY0066/2017). Y.F.-C. and A.R. thank the AEI for the FPU fellowships (FPU21/04747) and (FPU18/03192), respectively. We acknowledge Dr. João Carlos Lima for fruitful scientific discussions. Publisher Copyright: © 2023 The Authors. Published by American Chemical Society.Supramolecular synthetic transporters are crucial to understand and activate the passage across lipid membranes of hydrophilic effector molecules. Herein, we introduce photoswitchable calixarenes for the light-controlled transport activation of cationic peptide cargos across model lipid bilayers and inside living cells. Our approach was based on rationally designed p-sulfonatocalix[4]arene receptors equipped with a hydrophobic azobenzene arm, which recognize cationic peptide sequences at the nM range. Activation of membrane peptide transport is confirmed, in synthetic vesicles and living cells, for calixarene activators featuring the azobenzene arm in the E configuration. Therefore, this method allows the modulation of the transmembrane transport of peptide cargos upon Z-E photoisomerization of functionalized calixarenes using 500 nm visible light. These results showcase the potential of photoswitchable counterion activators for the light-triggered delivery of hydrophilic biomolecules and pave the way for potential applications in remotely controlled membrane transport and photopharmacology applications of hydrophilic functional biomolecules.publishersversionpublishe