Balancing Market Share Growth and Customer Profitability: Budget Allocation for Customer Acquisition and Retention

This study adds to the knowledge of budget allocation for customer acquisition and retention spending in an inertia segment.  The results indicate that when retention spending surpassed the optimal budget allocation, increased spending did not grow the expected value of customer equity.  Since the inertia segment is comprised of loyal customers, an examination of brand equity and its role in customer loyalty and its influence on customer equity are discussed

Using Resting-State Functional Connectivity of the Basal Ganglia as a Biomarker for Symptoms of Parkinson\u27s Disease

Parkinson\u27s disease (PD) is characterized by the degeneration of nigrostriatal dopaminergic neurons, resulting in dysfunctional cortico­-striato-­thalamic­cortical loops. Parkinson\u27s disease patients suffer from chronic movement disabilities as well as cognitive impairments and other nonmotor symptoms, which implies a system­wide effect on overall brain function. Because the disease currently has no cure, the discovery of a biomarker for specific PD symptoms is crucial for monitoring treatment potency. This study aimed to evaluate the validity of using functional connectivity between regions of the basal ganglia as a biomarker for specific symptoms of PD

Meeting Potential New U.S. Climate Goals

We explore the performance of a potential addition to U.S. climate policy using authority under Section 115 of the Clean Air Act, with special attention to distributional effects among the states. This portion of the Act concerns trans-boundary air pollution, and under its provisions a national greenhouse target could be allocated among the states, with the details of state implementation optionally guided by a model rule as under other provisions of the Act. With trading allowed among the states, such a measure could lead to a national price on the covered gases. While we adopt features of a possible Section 115 implementation, the illustrative analysis is applicable to similar cap-and-trade programs that might be adopted under other authorities. We investigate the implications of such a policy using MIT’s U.S. Regional Energy Policy (USREP) model, with its electric sector replaced by the Renewable Energy Development System (ReEDS) model developed by the U.S. National Renewable Energy Laboratory. Existing federal and state climate policies are assumed to remain in place, and a national constraint on CO2 emissions is applied to achieve 45% or 50% reductions below the 2005 level by 2030. We apply the policies in a Baseline and a Low-Cost Baseline, the latter with more aggressive assumptions of technology cost improvements. The U.S. is aggregated to 18 individual states and 12 multi-state regions, and the effects of the national emissions restriction are investigated under three alternative methods by which the EPA might allocate these targets among the states. We find the cost of achieving either target to be modest - allowing for nearly identical economic growth, even without taking account of air quality and climate benefits. The alternative allocation methods generate varying per capita revenue outcomes among states and regions and drive most of the welfare impact through a direct income effect. It is assumed that states distribute permit revenue to their residents in equal lump-sum payments, which leads to net benefits to lower income households. Under the Low-Cost Baseline, carbon prices in 2030 are about ⅓ those in the Baseline, and the overall pre-benefit welfare effects are negligible. Considering climate benefits evaluated using the social cost of carbon and particulate matter air pollution health benefits, less the mitigation costs, we find net benefits in all cases, with slightly larger net benefits with the 50% reduction below 2005 emissions

Stepwise Translocation of Dpo4 Polymerase during Error-Free Bypass of an oxoG Lesion

7,8-dihydro-8-oxoguanine (oxoG), the predominant lesion formed following oxidative damage of DNA by reactive oxygen species, is processed differently by replicative and bypass polymerases. Our kinetic primer extension studies demonstrate that the bypass polymerase Dpo4 preferentially inserts C opposite oxoG, and also preferentially extends from the oxoG•C base pair, thus achieving error-free bypass of this lesion. We have determined the crystal structures of preinsertion binary, insertion ternary, and postinsertion binary complexes of oxoG-modified template-primer DNA and Dpo4. These structures provide insights into the translocation mechanics of the bypass polymerase during a complete cycle of nucleotide incorporation. Specifically, during noncovalent dCTP insertion opposite oxoG (or G), the little-finger domain–DNA phosphate contacts translocate by one nucleotide step, while the thumb domain–DNA phosphate contacts remain fixed. By contrast, during the nucleotidyl transfer reaction that covalently incorporates C opposite oxoG, the thumb-domain–phosphate contacts are translocated by one nucleotide step, while the little-finger contacts with phosphate groups remain fixed. These stepwise conformational transitions accompanying nucleoside triphosphate binding and covalent nucleobase incorporation during a full replication cycle of Dpo4-catalyzed bypass of the oxoG lesion are distinct from the translocation events in replicative polymerases

Sex-Specific Variances in Anatomy and Blood Flow of the Left Main Coronary Bifurcation: Implications for Coronary Artery Disease Risk

Studies have shown marked sex disparities in Coronary Artery Diseases (CAD) epidemiology, yet the underlying mechanisms remain unclear. We explored sex disparities in the coronary anatomy and the resulting haemodynamics in patients with suspected, but no significant CAD. Left Main (LM) bifurcations were reconstructed from CTCA images of 127 cases (42 males and 85 females, aged 38 to 81). Detailed shape parameters were measured for comparison, including bifurcation angles, curvature, and diameters, before solving the haemodynamic metrics using CFD. The severity and location of the normalised vascular area exposed to physiologically adverse haemodynamics were statistically compared between sexes for all branches. We found significant differences between sexes in potentially adverse haemodynamics. Females were more likely than males to exhibit adversely low Time Averaged Endothelial Shear Stress along the inner wall of a bifurcation (16.8% vs. 10.7%). Males had a higher percentage of areas exposed to both adversely high Relative Residence Time (6.1% vs 4.2%, p=0.001) and high Oscillatory Shear Index (4.6% vs 2.3%, p<0.001). However, the OSI values were generally small and should be interpreted cautiously. Males had larger arteries (M vs F, LM: 4.0mm vs 3.3mm, LAD: 3.6mm 3.0mm, LCX:3.5mm vs 2.9mm), and females exhibited higher curvatures in all three branches (M vs F, LM: 0.40 vs 0.46, LAD: 0.45 vs 0.51, LCx: 0.47 vs 0.55, p<0.001) and larger inflow angle of the LM trunk (M: 12.9{\deg} vs F: 18.5{\deg}, p=0.025). Haemodynamic differences were found between male and female patients, which may contribute, at least in part, to differences in CAD risk. This work may facilitate a better understanding of sex differences in the clinical presentation of CAD, contributing to improved sex-specific screening, especially relevant for women with CAD who currently have worse predictive outcomes.Comment: 14 pages, 5 figure

The extreme luminosity states of Sagittarius A*

We discuss mm-wavelength radio, 2.2-11.8um NIR and 2-10 keV X-ray light curves of the super massive black hole (SMBH) counterpart of Sagittarius A* (SgrA*) near its lowest and highest observed luminosity states. The luminosity during the low state can be interpreted as synchrotron emission from a continuous or even spotted accretion disk. For the high luminosity state SSC emission from THz peaked source components can fully account for the flux density variations observed in the NIR and X-ray domain. We conclude that at near-infrared wavelengths the SSC mechanism is responsible for all emission from the lowest to the brightest flare from SgrA*. For the bright flare event of 4 April 2007 that was covered from the radio to the X-ray domain, the SSC model combined with adiabatic expansion can explain the related peak luminosities and different widths of the flare profiles obtained in the NIR and X-ray regime as well as the non detection in the radio domain.Comment: 18 pages, 13 figures, accepted by A&

A polar+equatorial wind model for broad absorption line quasars: I. Fitting the C IV BAL profiles

Despite all the studies, the geometry of the wind at the origin of the blueshifted broad absorption lines (BAL) observed in nearly 20% of quasars still remains a matter of debate. We want to see if a two-component polar+equatorial wind geometry can reproduce the typical BAL profiles observed in these objects. We built a Monte Carlo radiative transfer code (called MCRT) to simulate the line profiles formed in a polar+equatorial wind in which the photons, emitted from a spherically symmetric core are resonantly scattered. Our goal is to reproduce typical C IV line profiles observed in BAL quasars and to identify the parameters governing the line profiles. The two-component wind model appears to be efficient in reproducing the BAL profiles from the P Cygni-type profiles to the more complex ones. Some profiles can also be reproduced with a pole-on view. Our simulations provide evidence of a high-velocity rotation of the wind around the polar axis in BAL quasars with non P Cygni-type line profiles.Comment: 12 pages, 5 figures, accepted for publication in A&

The ROSAT Bright Source 1RXS J201607.0+251645: An Active Algol-type Binary

1RXS J201607.0251645 is identified to be an eclipsing binary for the first time. We present the preliminary observations in V band with the 0.6-m telescope for three years and the extensive observations in V and R band with the 0.8-m telescope for six nights respectively. The light curve of the system is EB type. Five light minimum times were obtained and the orbital period of 0.388058d(0.00044d) is determined. The photometric solution given by the 2003-version Wilson-Devinney program suggests the binary is a semi-detached system with the photometric mass ratio 0.895(0.006), which probably comprise a G5 primary and an oversize K5 secondary. The less massive component has completely filled up its Roche lobe, while the other almost fills its Roche lobe with the filling factor of 93.4%. The system shows a varying O'Connell effect in its phase folded diagrams from 2005 to 2007, and is X-ray luminous with log(LXLbol)3.27. Possible mechanisms to account for these two phenomena are discussed. Finally, we infer the binary may be in thermal oscillation predicted by thermal relaxation oscillation (TRO) theory or may evolve into a contact binary.Comment: 16 pages, 7 figures, published by RA