A general model of insurance and investment risk diversification

This article presents a model of insurance and investment risk diversification. An in-depth analysis of the mathematical formulation of the risk is presented. In this regard, we introduce a new concept called the substitution principle to formulate the model rigorously. We show that, if the investment risks are normally non-linear, the insurance risks are linear in nature. This proves that the well-known diversification principle has to be viewed differently in finance and in insurance.     

Probing shapes of very neutron deficientZ≈82 nuclei using the recoil-decay tagging method

The JYFL gas-filled recoil separator, RITU, combined with efficient Ge-detector arrays has been employed in in-beam γ-ray studies of very neutron-deficient nuclei close to theZ=82 shell. Gamma-rays from nuclei produced at the few μb cross-section level have been detected.     

ResonSense: simple linear fluorescent probes for quantitative homogeneous rapid polymerase chain reaction

Here we report a strand-specific fluorescent homogeneous assay format for rapid polymerase chain reaction (PCR). A number of similar assays are commonly used for research applications and are an ideal solution for a closed tube quantitative PCR. These assays use fluorescent resonant energy transfer (FRET) between donor and acceptor fluorescent moieties as the reporting mechanism. However, for different reasons these assays do not report amplification when very rapid cycling times are used. This is because current assays, such as TaqMan^®, are limited, in terms of assay speed, by the 5′-3′ exonuclease activity of Taq DNA polymerase. Other assays based on hybridisation require either a complex de-conformational event to occur, or require more than one probe to report amplification. Reducing the complexity of the experiment reduces costs in terms of design, optimisation and manufacture. Here, we describe ResonSense^® chemistries that use a simple linear fluorescent-labelled probe and a DNA minor-groove binding dye as either donor or acceptor moieties in a homogeneous assay format on the LightCycler^®. This assay format will provide for rapid analysis of samples and so it is particularly well suited to point-of-use testing.     

Ab initio study of ground state MH2, HMHe+ and MHe2(2+), M = Mg, Ca

The ground states of MH2, HMHe+ and MHe2(2+) (M = Mg, Ca) have been investigated using relativistically-corrected CCSD(T), IC-MRCI and IC-MRCI+Q, in conjunction with ANO-RCC (Mg, Ca) and aug-cc-pVQZ (H, He) basis sets. The ground states of all magnesium species are predicted to be linear, in agreement with predicted trends. Conversely, HCaHe+ and CaHe2(2+) were determined to be quasi-linear species, with linear-inversion barriers of ca. 115 and 3 cm(-1), respectively. For CaH2, a stationary point on the molecular potential energy surface corresponding to a non-linear equilibrium structure was not observed. Trends in bonding, dissociative potential well-depths and spectroscopic constants for these species have been considered with regards to isoelectronic and isovalent reasoning. These trends are consistent with helium and hydrogen forming electrostatic and covalent bonds with the metal ion, respectively.     

Do The Twist: Efficient Heavy-Atom-Free Visible Light Polymerization Facilitated by Spin-Orbit Charge Transfer Inter-system Crossing

The use of visible light to drive polymerizations with spatiotemporal control offers a mild alternative to contemporary UV-light-based production of soft materials. In this spectral region, photoredox catalysis represents the most efficient polymerization method, yet it relies on the use of heavy-atoms, such as precious metals or toxic halogens. Herein, spin-orbit charge transfer intersystem crossing from boron dipyrromethene (BODIPY) dyads bearing twisted aromatic groups is shown to enable efficient visible light polymerizations in the absence of heavy-atoms. A ≈5–15× increase in polymerization rate and improved photostability was achieved for twisted BODIPYs relative to controls. Furthermore, monomer polarity had a distinct effect on polymerization rate, which was attributed to charge transfer stabilization based on ultrafast transient absorption and phosphorescence spectroscopies. Finally, rapid and high-resolution 3D printing with a green LED was demonstrated using the present photosystem.     

Reactivity and selectivity in the inhibition of elastase by 3-oxo-beta-sultams and in their hydrolysis

3-oxo-beta-sultams are both beta-sultams and beta-lactams and are a novel class of time-dependent inhibitors of elastase. The inhibition involves formation of a covalent enzyme-inhibitor adduct with transient stability by acylation of the active-site serine resulting from substitution at the carbonyl centre of the 3-oxo-beta-sultam, C-N fission, and expulsion of the sulfonamide. The lead compound, N-benzyl-4,4-dimethyl-3-oxo-beta-sultam 1 is a reasonably potent inhibitor against porcine pancreatic elastase with a second-order rate constant of 768 M(-1) s(-1) at pH 6, but also possesses high chemical reactivity with a half-life for hydrolysis of only 6 mins at the same pH in water. Interestingly, the hydrolysis of 3-oxo-beta-sultams occurs at the sulfonyl centre with S-N fission and expulsion of the amide leaving group, whereas the enzyme reaction occurs at the acyl centre. Increasing selectivity between these two reactive centres was explored by examining the effect of substituents on the reactivity of 3-oxo-beta-sultam towards hydrolysis and enzyme inhibition. The inhibition activity against porcine pancreatic elastase has a much higher sensitivity to substituent variation than does the rate of alkaline hydrolysis. A difference of 2000-fold is observed in the second-order rate constants, k(i), for inhibition whereas there is only a 100-fold difference in the second-order rate constants, k(OH), for alkaline hydrolysis within the series. The higher sensitivity of enzyme inhibition to substituents than that of simple chemical reactivity indicates a significant degree of molecular recognition of the 3-oxo-beta-sultams by the enzyme.     

Collectivity in neutron-deficient Pb and Po nuclei

Lifetimes of low-lying yrast states in ¹⁸⁶Pb and ¹⁹⁴Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in ¹⁸⁸Pb up to the 8⁺ state were carried out using the recoil gating method. The deformation parameters and for the prolate (^186,188Pb) and the oblate (¹⁹⁴Po) bands, respectively, have been extracted from the measured lifetimes. 27.70.+q–     

Electrodeposition of Ni and Te‐doped Cobalt Triantimonide in Citrate Solutions

Skutterudite compounds form a new class of potential candidates for thermoelectric applications. Cobalt triantimonide (CoSb₃) shows good thermoelectric properties at medium and high temperatures. Doping this system with substitution elements, for either Co or Sb or both, may result in an increase of the thermoelectric figure of merit (ZT). This work focused on the electrochemical doping and characterization of films and nanowires of Co‐Sb system in citrate solutions using gold‐coated PCTE templates. The electrodeposition was performed on gold surface that was pre‐treated electrochemically to ensure reproducible results. The electrochemical treatment acted as an annealing process for the surface, which resulted in an increase in Au(111) as demonstrated by XRD. Detailed electrochemical studies including deposition‐stripping experiments was performed in order to develop a better understanding of the co‐deposition kinetics and a better control over the composition of doped Co‐Sb system. Scanning electron microscopy (SEM/EDS) helped study the morphology and the composition of the doped and undoped Co‐Sb system. Co‐deposition of Co‐Sb showed that the amount of Co is higher in nanowires than in film or mushroom caps due to the slow Sb deposition rate dictated by slow Sb(III) complex diffusion. Doped nanowires have been also obtained. Both Ni and Te electrochemical doping of the Co‐Sb system affected the composition of the deposit but there was no effect on nanowire morphology.     

Raman scattering of KI:Ag+: Exploration of a nearly unstable defect-lattice configuration

Abstract

The Raman spectra of Ag⁺ in KI exhibit between 6K and 25K two resonant modes and quasi-elastic scattering (QES), each with a different temperature behavior. The low-temperature Raman and infrared (ir) spectral features can be described within a harmonic force-constant model, which does not however account for the dramatic temperature dependence of the experimental data. They are compatible with a population transfer from a low-temperature on-center configuration to a second elastic configuration, in which the Ag⁺ ion is displaced from the regular lattice site. The QES, which dominates the Raman spectra above 20K, may reflect different types of rotational diffusion or the presence of a third elastic configuration.