The Quest for Purchasing Power Parity with a Series-specific Unit Root Test Using Panel Data

A unit root testing procedure is presented that exploits the well-established power advantages of panel estimation while rectifying a deficiency in other panel unit root tests. This procedure, which takes into account contemporaneous cross-correlation and heterogeneous serial correlation of the regression residuals, allows determination of which members of the panel reject the null hypothesis of a unit root and which do not. Applying the procedure to real exchange rates yields results that are in broad agreement with those obtained from single-equation unit root tests. There is little evidence that a unit root can be rejected in dollar-based real exchange rates for the floating rate period.Marketing,

Z-Selective Homodimerization of Terminal Olefins with a Ruthenium Metathesis Catalyst

The cross-metathesis of terminal olefins using a novel ruthenium catalyst results in excellent selectivity for the Z-olefin homodimer. The reaction was found to tolerate a large number of functional groups, solvents, and temperatures while maintaining excellent Z-selectivity, even at high reaction conversions

Making Medical Homes Work: Moving From Concept to Practice

Explores practical considerations for implementing a medical home program of physician practices committed to coordinating and integrating care based on patient needs and priorities, such as how to qualify medical homes and how to match patients to them

γ-Aminobutyric Acid Increases the Water Accessibility of M3 Membrane-Spanning Segment Residues in γ-Aminobutyric Acid Type A Receptors

Abstractγ-Aminobutyric acid type A (GABAA) receptors are members of the ligand-gated ion channel gene superfamily. Using the substituted cysteine accessibility method, we investigated whether residues in the α1M3 membrane-spanning segment are water-accessible. Cysteine was substituted, one at a time, for each M3 residue from α1Ala291 to α1Val307. The ability of these mutants to react with the water-soluble, sulfhydryl-specific reagent pCMBS− was assayed electrophysiologically. Cysteines substituted for α1Ala291 and α1Tyr294 reacted with pCMBS− applied both in the presence and in the absence of GABA. Cysteines substituted for α1Phe298, α1Ala300, α1Leu301, and α1Glu303 only reacted with pCMBS− applied in the presence of GABA. We infer that the pCMBS− reactive residues are on the water-accessible surface of the protein and that GABA induces a conformational change that increases the water accessibility of the four M3 residues, possibly by inducing the formation of water-filled crevices that extend into the interior of the protein. Others have shown that mutations of α1Ala291, a water-accessible residue, alter volatile anesthetic and ethanol potentiation of GABA-induced currents. Water-filled crevices penetrating into the interior of the membrane-spanning domain may allow anesthetics and alcohol to reach their binding sites and thus may have implications for the mechanisms of action of these agents

Modeling biological rhythms in failure time data

BACKGROUND: The human body exhibits a variety of biological rhythms. There are patterns that correspond, among others, to the daily wake/sleep cycle, a yearly seasonal cycle and, in women, the menstrual cycle. Sine/cosine functions are often used to model biological patterns for continuous data, but this model is not appropriate for analysis of biological rhythms in failure time data. METHODS: We adapt the cosinor method to the proportional hazards model and present a method to provide an estimate and confidence interval of the time when the minimum hazard is achieved. We then apply this model to data taken from a clinical trial of adjuvant of pre-menopausal breast cancer patients. RESULTS: The application of this technique to the breast cancer data revealed that the optimal day for pre-resection incisional or excisional biopsy of 28-day cycle (i. e. the day associated with the lowest recurrence rate) is day 8 with 95% confidence interval of 4–12 days. We found that older age, fewer positive nodes, smaller tumor size, and experimental treatment were predictive of longer relapse-free survival. CONCLUSION: In this paper we have described a method for modeling failure time data with an underlying biological rhythm. The advantage of adapting a cosinor model to proportional hazards model is its ability to model right censored data. We have presented a method to provide an estimate and confidence interval of the day in the menstrual cycle where the minimum hazard is achieved. This method is not limited to breast cancer data, and may be applied to any biological rhythms linked to right censored data

Z-Selectivity in Olefin Metathesis with Chelated Ru Catalysts: Computational Studies of Mechanism and Selectivity

The mechanism and origins of Z-selectivity in olefin metathesis with chelated Ru catalysts were explored using density functional theory. The olefin approaches from the “side” position of the chelated Ru catalysts, in contrast to reactions with previous unchelated Ru catalysts that favor the bottom-bound pathway. Steric repulsions between the substituents on the olefin and the N-substituent on the N-heterocyclic carbene ligand lead to highly selective formation of the Z product

On the motion of hairy black holes in Einstein-Maxwell-dilaton theories

Starting from the static, spherically symmetric black hole solutions in massless Einstein-Maxwell-dilaton (EMD) theories, we build a "skeleton" action, that is, we phenomenologically replace black holes by an appropriate effective point particle action, which is well suited to the formal treatment of the many-body problem in EMD theories. We find that, depending crucially on the value of their scalar cosmological environment, black holes can undergo steep "scalarization" transitions, inducing large deviations to the general relativistic two-body dynamics, as shown, for example, when computing the first post-Keplerian Lagrangian of EMD theories

Sustainability and professional sales: a review and future research agenda

Sustainability has become a consideration for every firm operating in today’s business landscape. Scholars are tasked with uncovering bridges and barriers to successfully implement sustainability strategies, and the academic community has largely responded. However, while sustainability research has proliferated across business disciplines, it is conspicuously missing from professional selling and sales management. This is partly due to conceptual ambiguity, but also because sustainability generally involves firm-level policies and programs, and therefore domains like consumer behavior, marketing strategy, and supply chain management have occupied the space. This is problematic because while executives develop sustainability strategies, the sales force is responsible for conveying those priorities to external stakeholders. Therefore, the goals of our manuscript are to: 1) organize and refine the definition of sustainability in a professional selling context, 2) review relevant literature that examines sustainability in that context, 3) explore emergent themes from this review that 4) reveal gaps in our understanding, and 5) present a research agenda for sales scholars to bridge these gaps and advance our understanding of the role of sustainability in sales and vice versa