An Infrared 2D-COS Study of Fibril Formation

Aprovat per Decret de l'Alcaldia de 06-07-200

CEO pay and family firm heterogeneity: A behavioral agency model perspective

\ua9 The Author(s) 2021. We study the effects of family control on CEO pay from the perspective of behavioral agency model (BAM), with particular focus on family firm’s generational stage and CEO family ties. Using a panel of Australian listed firms, we find that family firms present lower total and variable CEO pay, showing also less pay disparity between the CEO and other top executives. We also find that multi-generational family firms and those run by non-family CEOs offer higher total and variable CEO pay and present high pay disparity. The BAM and family’s aversion to socioemotional wealth loss can explain the effects of family control based on the pursuing of non-financial family goals. The decline of these goals derived from the aging of the firm and the hiring of external CEOs shape family control and should be considered in the design of executive compensation policies and by external parties when assessing their suitability. JEL CLASSIFICATION: G30; G32; G34; G3

Phosphorylation of the carboxy-terminal domain of histone H1: effects on secondary structure and DNA condensation

Linker histone H1 plays an important role in chromatin folding. Phosphorylation by cyclin-dependent kinases is the main post-translational modification of histone H1. We studied the effects of phosphorylation on the secondary structure of the DNA-bound H1 carboxy-terminal domain (CTD), which contains most of the phosphorylation sites of the molecule. The effects of phosphorylation on the secondary structure of the DNA-bound CTD were site-specific and depended on the number of phosphate groups. Full phosphorylation significantly increased the proportion of β-structure and decreased that of α-helix. Partial phosphorylation increased the amount of undefined structure and decreased that of α-helix without a significant increase in β-structure. Phosphorylation had a moderate effect on the affinity of the CTD for the DNA, which was proportional to the number of phosphate groups. Partial phosphorylation drastically reduced the aggregation of DNA fragments by the CTD, but full phosphorylation restored to a large extent the aggregation capacity of the unphosphorylated domain. These results support the involvement of H1 hyperphosphorylation in metaphase chromatin condensation and of H1 partial phosphorylation in interphase chromatin relaxation. More generally, our results suggest that the effects of phosphorylation are mediated by specific structural changes and are not simply a consequence of the net charge

Experimental and natural infections of severe acute respiratory syndrome-related coronavirus 2 in pets and wild and farm animals

The severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has spread globally and has led to extremely high mortality rates. In addition to infecting humans, this virus also has infected animals. Experimental studies and natural infections showed that dogs have a low susceptibility to SARS-CoV-2 infection, whereas domesticated cats and other animals in the family Felidae, such as lions, tigers, snow leopards, and cougars, have a high susceptibility to viral infections. In addition, wild white-tailed deer, gorillas, and otters have been found to be infected by SARS-CoV-2. Furry farm animals, such as minks, have a high susceptibility to SARS-CoV-2 infection. The virus appears to spread among minks and generate several new mutations, resulting in increased viral virulence. Furthermore, livestock animals, such as cattle, sheep, and pigs, were found to have low susceptibility to the virus, whereas chicken, ducks, turkeys, quail, and geese did not show susceptibility to SARS-CoV-2 infection. This knowledge can provide insights for the development of SARSCoV-2 mitigation strategies in animals and humans. Therefore, this review focuses on experimental (both replication and transmission) in vitro, ex vivo, and in vivo studies of SARS-CoV-2 infections in pets and in wild and farm animals, and to provide details on the mechanism associated with natural infection. Copyright: Mastutik, et al

Rational parametrization of conchoids to algebraic curves

We study the rationality of each of the components of the conchoid to an irreducible algebraic affine plane curve, excluding the trivial cases of the lines through the focus and the circle centered at the focus and radius the distance involved in the conchoid. We prove that conchoids having all their components rational can only be generated by rational curves. Moreover, we show that reducible conchoids to rational curves have always their two components rational. In addition, we prove that the rationality of the conchoid component, to a rational curve, does depend on the base curve and on the focus but not on the distance. As a consequence, we provide an algorithm that analyzes the rationality of all the components of the conchoid and, in the affirmative case, parametrizes them. The algorithm only uses a proper parametrization of the base curve and the focus and, hence, does not require the previous computation of the conchoid. As a corollary, we show that the conchoid to the irreducible conics, with conchoid-focus on the conic, are rational and we give parametrizations. In particular we parametrize the Limaçons of Pascal. We also parametrize the conchoids of Nicomedes. Finally, we show how to find the foci from where the conchoid is rational or with two rational components

An Algebraic Analysis of Conchoids to Algebraic Curves

We study the conchoid to an algebraic affine plane curve C from the perspective of algebraic geometry, analyzing their main algebraic properties. Beside C, the notion of conchoid involves a point A in the affine plane (the focus) and a nonzero field element d (the distance).We introduce the formal definition of conchoid by means of incidence diagrams.We prove that the conchoid is a 1-dimensional algebraic set having atmost two irreducible components. Moreover, with the exception of circles centered at the focus A and taking d as its radius, all components of the corresponding conchoid have dimension 1. In addition, we introduce the notions of special and simple components of a conchoid. Furthermore we state that, with the exception of lines passing through A, the conchoid always has at least one simple component and that, for almost every distance, all the components of the conchoid are simple. We state that, in the reducible case, simple conchoid components are birationally equivalent to C, and we show how special components can be used to decide whether a given algebraic curve is the conchoid of another curve

Exploring Deep-Sea Biodiversity in the Porcupine Bank (NE Atlantic) through Fish Integrative Taxonomy

This study combined morphological and molecular approaches to the species assignment of several rare or poorly known deep-water fishes caught between 549 and 1371 m depth during a Spanish bottom trawl survey in the Porcupine Bank, west of Ireland. The following fish species were identified: Nessorhamphus ingolfianus (Schmidt, 1912), Borostomias antarcticus (Lönnberg 1905), Scopelosaurus lepidus (Krefft and Maul 1955), Bathypterois dubius Vaillant, 1888, Evermannella balbo (Risso, 1820), Antimora rostrata (Günther, 1878), Melanonus zugmayeri Norman, 1930, Lyconus brachycolus Holt and Byrne, 1906; Paraliparis hystrix Merrett, 1983, Neocyttus helgae (Holt and Byrne, 1908); Platyberyx opalescens Zugmayer, 1911; Howella atlantica Post and Quéro, 1991, Lycodes terraenovae Collett, 1896 and Pseudoscopelus altipinnis Parr, 1933. The presence of L. brachycolus, P. opalescens and P. altipinnis is reported for the first time in the Bank. The DNA barcoding results were largely consistent with morphological identification in 10 species but four did not fit the current taxonomy, indicating cases of potential cryptic speciation, misidentification, synonymy or recent diversification. Among them, the results strongly suggest that P. garmani and P. hystrix are conspecific, making P. hystrix a junior synonym of P. garmani.Versión del edito