Higher-order supersymmetric quantum mechanics

We review the higher-order supersymmetric quantum mechanics (H-SUSY QM), which involves differential intertwining operators of order greater than one. The iterations of first-order SUSY transformations are used to derive in a simple way the higher-order case. The second order technique is addressed directly, and through this approach unexpected possibilities for designing spectra are uncovered. The formalism is applied to the harmonic oscillator: the corresponding H-SUSY partner Hamiltonians are ruled by polynomial Heisenberg algebras which allow a straight construction of the coherent states.Comment: 42 pages, 12 eps figure

Selective Acylation of Nucleosides, Nucleotides, and Glycerol-3- phosphocholine in Water

A convenient selective synthesis of 2′,3′-di-O-acetyl-nucleo- tide-5′-phosphates, 2′,3′-di-O-acetyl-nucleotide-5′-triphosphates and 2′,3′,5′-tri-O-acetyl-nucleosides in water has been developed. Further- more, a long-chain selective glycerol-3-phosphocholine diacylation is elucidated. These reactions are environmentally benign, rapid, high yielding, and the products are readily purified. Importantly, this reac- tion may indicate a prebiotically plausible reaction pathway for the se- lective acylation of key metabolites to facilitate their incorporation into protometabolism

Optical fibers to measure temperature vertical profile at sea

The paper is focus in the use the optical fiber to measure the temperature in various heigh at the same time to get a temperature vertical variation. The temperature measurements are puntual while the Bragg gratings located in the fiber.Peer Reviewe

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

The parasporal crystals of Bacillus pumilus strain 15.1: a potential virulence factor?

Bacillus pumilus strain 15.1 was previously found to cause larval mortality in the Med-fly 27 Ceratitis capitata and was shown to produce crystals in association with the spore. As 28 parasporal crystals are well-known as invertebrate-active toxins in entomopathogenic 29 bacteria such as Bacillus thuringiensis (Cry and Cyt toxins) and Lysinibacillus sphaericus (Bin 30 and Cry toxins), the B. pumilus crystals were characterised. The crystals were composed of a 31 45 kDa protein that was identified as an oxalate decarboxylase by peptide mass 32 fingerprinting, N-terminal sequencing and by comparison with the genome sequence of strain 33 15.1. Synthesis of crystals by a plasmid-cured derivative of strain 15.1 (produced using a 34 novel curing strategy), demonstrated that the oxalate decarboxylase was encoded 35 chromosomally. Crystals spontaneously solubilized when kept at low temperatures and the 36 protein produced was resistant to trypsin treatment. The insoluble crystals produced by 37 B. pumilus 15.1 did not show significant toxicity when bioassayed against C. capitata larvae, 38 but once the OxdD protein was solubilized, an increase of toxicity was observed. We also 39 demonstrate that the OxdD present in the crystals has oxalate decarboxylate activity as the 40 formation of formate was detected, which suggests a possible mechanism for B. pumilus 15.1 41 activity. To our knowledge, the characterization of the B. pumilus crystals as oxalate 42 decarboxylase is the first report of the natural production of parasporal inclusions of an 43 enzyme