The Yield Curve through Time and Across Maturities

We develop an unobserved component model in which the short-term interest rate is composed of a stochastic trend and a stationary cycle. Using the Nelson-Siegel model of the yield curve as inspiration, we estimate an extremely parsimonious state-space model of interest rates across time and maturity. Our stochastic process generates a three-factor model for the term structure. At the estimated parameters, trend and slope factors matter while the third factor is empirically unimportant. Our baseline model fits the yield curve well. Model generated estimates of uncertainty are positively correlated with estimated term premia. An extension of the model with regime switching identifies a high-variance regime and a low-variance regime, where the high-variance regime occurs rarely after the mid-1980s. The term premium is higher, and more so for yields of short maturities, in the high-variance regime than that in the low-variance regime. The estimation results support our model as a simple and yet reliable framework for modeling the term structure.

Syntheses, Structures, and Photoluminescence of 1-D Lanthanide Coordination Polymers

Five new lanthanide 1-D coordination polymers are reported which are formed from flexible salen type Schiff-base ligands H(2)L and H(2)L' (H(2)L = N, N(1)-ethylene bis(salicylideneimine); H(2)L' = N,N(1)-bis(3-methoxysalicylidene) ethylene-1,2-diamine). The polymeric structures are formed by bridging neutral H(2)L units in the case of {[Ln(2)L(2)(CF(3)SO(3))(H(2)L)(4)(MeOH)]center dot CF(3)SO(3)}(n) (Ln = Eu (1), Nd (2) and Er (3)), and by acetate (OAc(-)) groups in [Yb(2)(L)(2)(OAc)(2)(MeOH)(2)](n) (4) and {[Tb(3)(L')(2)(OAc)(5)]center dot Et(2)O center dot(MeOH)(0.5)}(n) (5). The structures of 1-5 were determined by single crystal X-ray crystallographic studies and the luminescence properties of 1 and 5 in MeOH solution were determined.ong Kong Baptist University FRG/06-07/II-16Hong Kong Research Grants Council HKBU 202407Robert A. Welch Foundation F-816Texas Higher Education Coordinating Board ARP 003658-0010-2006Petroleum Research FundAmerican Chemical Society 47014-AC5Chemistr

The Transformation in Who is Expected to Work in the United States and How it Changed the Lives of Single Mothers and People with Disabilities

In the 1990s, social expectations of single mothers shifted towards the notion that most should, could, and would work, if given the proper incentives. This shift in expectations culminated in the passage of the Personal Responsibility and Work Opportunity Reconciliation Act in 1996, commonly known as welfare reform. As a result, ADFC/TANF caseloads fell along with cash transfers to single mothers who did not work. A decade later the earnings and household income of single mothers are significantly higher and moving more in synch with the U.S. economy. In stark contrast and despite espoused goals to the contrary, public policies toward working age men and women with disabilities have remained imbued with the notion that most cannot and thus, would not work, no matter what incentives they faced. As a result, SSDI/SSI expenditures and caseloads have increased and the earnings and household income of working age men and women with disabilities have fallen, leaving them even further behind the average working age American than they were a decade ago. Using data from the Current Population Survey we follow the economic well-being and employment of single mothers and working age men and women with disabilities over the past two major United States business cycles (1982-1993 and 1993-2004) and show that despite the dramatic decline in AFDC/TANF funding, single mothers’ economic well-being, labor earnings and employment all have risen substantially. In contrast, despite the dramatic increase in SSDI/SSI funding, the economic wellbeing of working age men and women with disabilities remained stagnant, as their labor earnings and employment plummeted.

Toxicity issues pertaining to burning pyrotechnics

International audienceWe all know that normal operations with pyrotechnic compositions or other energetic materials, apart from the desired effect (e.g.: controlled blast from high explosives, propulsive power resulting from propellant gas pressure, various visible or sound effects from fireworks...) lead to the release of various products (gases, vapours, aerosols) in the environment, in relation with the chemicals, the reactions involved and some physical parameters. Although discussed from time to time by experts, and contrary to the case of 'conventional' fires, toxicity and environmentally related questions associated with burning pyrotechnics, have received far less attention than they actually deserve. Therefore, this paper supports an analysis of our current understanding of the sole toxicity problems (acute toxicity, sub-acute toxicity concerns...) emerging with all types of burning pyrotechnics, at the light of what has been established to address 'normal' fires in built environments. The paper provides an analysis of the regulatory context, lessons from past accidents, typology of chemistry and reactions of pyrotechnics, and some contribution to the analysis is supported by experiments on smoke powders, one significant family of products belonging to pyrotechnics. Eventually, a discussion is proposed to envisage pathways to go further in learning on those important issues

The First Example of Tb-3-Containing Metallopolymer-Type Hybrid Materials with Efficient and High Color-Purity Green Luminescence

In the series of homo-leptic trinuclear complexes {[Ln(3)(L)(4)Cl-4(MeOH)(H2O)]center dot Cl} (Ln = La, 1; Ln = Eu, 2; Ln = Tb, 3 or Ln = Gd, 4) self-assembled from the allyl-modified benzimidazole-type ligand HL (4-allyl-2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol) and LnCl(3)center dot 6H(2)O, a suitable energy level match endows efficient green luminescence (Phi(overall) = 72%) of Tb-3-arrayed complex 3. The copolymerization between each of these complex monomers 1-4 and C=C-containing MMA (methyl methacrylate) or NBE (norbornene) shows that degradative chain transfer of the terminal four flexible allyl groups within restrains their radical polymerization with MMA while it does not hinder their effective ring-opening metathesis polymerization (ROMP) with NBE. Thus, two kinds of PMMA-supported doping hybrid materials 1@PMMA, 2@PMMA, 3@PMMA and 4@PMMA and PNBE-supported metallopolymer-type hybrid materials Poly( NBE-1), Poly(NBE-2), Poly(NBE-3) and Poly(NBE-4) are obtained, respectively. Especially for both 3@PMMA and Poly(NBE-3) with high color-purity characteristic green emission of Tb3+ ions, improved physical properties including significantly enhanced luminescence (Phi(overall) = 76% or 83%) are observed, and covalent-bonding endows a higher-concentration self-quenching as compared to physical doping.National Natural Science Foundation 21373160, 91222201, 21173165Program for New Century Excellent Talents in University from the Ministry of Education of China NCET-10-0936Doctoral Program of Higher Education 20116101110003Science and Technology and Innovation Project of Shaanxi Province 2012KTCQ01-37Graduate Innovation and Creativity Fund (Visiting Learner) of Northwest University in P. R. ChinaChemistr

Near-Infrared (NIR) Luminescent Homoleptic Lanthanide Salen Complexes Ln(4)(Salen)(4) (Ln = Nd, Yb Or Er)

The series of homoleptic tetranuclear [Ln(4)(L)(2)(HL)(2)(NO3)(2)(OH)(2)]center dot 2(NO3) (Ln = Nd, 1; Ln = Yb, 2; Ln = Er, 3; Ln = Gd, 4) have been self-assembled from the reaction of the Salen-type Schiff-base ligand H2L with Ln(NO3)(3)center dot 6H(2)O (Ln = Nd, Yb, Er or Gd), respectively (H2L: N, N'-bis(salicylidene) cyclohexane-1,2-diamine). The result of their photophysical properties shows that the strong and characteristic NIR luminescence for complexes 1 and 2 with emissive lifetimes in microsecond ranges are observed and the sensitization arises from the excited state (both (LC)-L-1 and (LC)-L-3) of the Salen-type Schiff-base ligand with the flexible linker.National Natural Science Foundation 21173165, 20871098Ministry of Education of China NCET-10-0936Higher Education of China 20116101110003State Key Laboratory of Structure Chemistry 20100014Education Committee Foundation of Shaanxi Province 11JK0588Hong Kong Research Grants Council, P. R. of China HKBU 202407, FRG/06-07/II-16)Hong Kong Research Grants Council, Robert A. Welch Foundation F-816Texas Higher Education Coordinating Board ARP 003658-0010-2006Petroleum Research Fund 47014-AC5Chemistr

Consumers\u27 Repurchase Probability in Online Marketplace: A Belief Updating Perspective

It is commonly recognized that online transactions are “one-shot” transactions. However, a contemporary dataset from a dominant online marketplace in China reveals that averagely 24.3% transactions are repurchase transactions. Given that consumers already have purchase experience with a specific seller, their repurchase behavior may be influenced by both the seller’s reputation and their perceived seller performance. A consequent research question is: Whether and how do these two streams of information jointly affect consumers’ repurchase behavior? We adopt a belief update model, and also collect actual transaction data to examine this research question. Our findings include: (1) both seller reputation and consumers’ perceived seller performance have positive effects on consumers’ repurchase probability; (2) the effect of seller reputation is positively moderated by performance ambiguity; (3) consumers’ perceived seller performance has stronger effects on their repurchase probability when the seller has low reputation (vs. high reputation)