Using Bid Design to Measure the Boundaries of WTP

We examine the extent to which bid design provides an informative anchor that influences the context in which individuals evaluate willingness to pay questions. We postulate that agents who are uncertain over possible states of nature that may arise when consuming a good use bid design as a means to resolve such uncertainty. Furthermore, we hypothesize that the impact of bid design on estimated WTP is less pronounced for experienced agents that have observed more draws from nature. We use three measure of bid design to evaluate our conjectures; (i) the mean of bid amounts, (ii) the absolute value of the difference between bid amounts, and (iii) the ratio of the mean to the spread. We interact proxies for individual experience with our measure of bid design to evaluate if such characteristics attenuate the impact of bid design on WTP estimates. We find the likelihood an individual says Yes to a given bid systematically varies with measures of bid design. This suggests that bid design provides an informative anchor and can be used to identify probabilistic boundaries for WTP.Demand and Price Analysis,

The Effect of Discovery Systems on Online Journal Usage: A Longitudinal Study

Many academic libraries are implementing discovery services as a way of giving their users a single comprehensive search option for all library resources. These tools are designed to change the research experience, yet very few studies have investigated the impact of discovery service implementation. This study examines one aspect of that impact by asking whether usage of publisher-hosted journal content changes after implementation of a discovery tool. Libraries that have begun using the four major discovery services have seen an increase in usage of this content, suggesting that for this particular type of material, discovery services have a positive impact on use. Though all discovery services significantly increased usage relative to a no discovery service control group, some had a greater impact than others, and there was extensive variation in usage change among libraries using the same service. Future phases of this study will look at other types of content

The Effect of Discovery Systems on Online Journal Usage: A Longitudinal Study

Many academic libraries are implementing discovery services as a way of giving their users a single comprehensive search option for all library resources. These tools are designed to change the research experience, yet very few studies have investigated the impact of discovery service implementation. This study examines one aspect of that impact by asking whether usage of publisher-hosted journal content changes after implementation of a discovery tool. Libraries that have begun using the four major discovery services have seen an increase in usage of this content, suggesting that for this particular type of material, discovery services have a positive impact on use. Though all discovery services significantly increased usage relative to a no discovery service control group, some had a greater impact than others, and there was extensive variation in usage change among libraries using the same service. Future phases of this study will look at other types of content

The Intrinsic Absorber in QSO 2359-1241: Keck and HST Observations

We present detailed analyses of the absorption spectrum seen in QSO 2359-1241 (NVSS J235953-124148). Keck HIRES data reveal absorption from twenty transitions arising from: He I, Mg I, Mg II, Ca II, and Fe II. HST data show broad absorption lines (BALs) from Al III 1857, C IV 1549, Si IV 1397, and N V 1240. Absorption from excited Fe II states constrains the temperature of the absorber to 2000K < T < 10,000K and puts a lower limit of 10^5 cm^{-3} on the electron number density. Saturation diagnostics show that the real column densities of He I and Fe II can be determined, allowing to derive meaningful constraints on the ionization equilibrium and abundances in the flow. The ionization parameter is constrained by the iron, helium and magnesium data to -3.0 < log(U) < -2.5 and the observed column densities can be reproduced without assuming departure from solar abundances. From comparison of the He I and Fe II absorption features we infer that the outflow seen in QSO 2359-1241 is not shielded by a hydrogen ionization front and therefore that the existence of low-ionization species in the outflow (e.g., Mg II, Al III, Fe II) does not necessitate the existence of such a front. We find that the velocity width of the absorption systematically increases as a function of ionization and to a lesser extent with abundance. Complementary analyses of the radio and polarization properties of the object are discussed in a companion paper (Brotherton et al. 2000).Comment: 30 pages, 9 figures, in press with the Ap

An α/β Hydrolase and Associated Per-ARNT-Sim Domain Comprise a Bipartite Sensing Module Coupled with Diverse Output Domains

The RsbQ α/β hydrolase and RsbP serine phosphatase form a signaling pair required to activate the general stress factor σB of Bacillus subtilis in response to energy limitation. RsbP has a predicted N-terminal Per-ARNT-Sim (PAS) domain, a central coiled-coil, and a C-terminal protein phosphatase M (PPM) domain. Previous studies support a model in which RsbQ provides an activity needed for PAS to regulate the phosphatase domain via the coiled-coil. RsbQ and the PAS domain (RsbP-PAS) therefore appear to form a sensory module. Here we test this hypothesis using bioinformatic and genetic analysis. We found 45 RsbQ and RsbP-PAS homologues encoded by adjacent genes in diverse bacteria, with PAS and a predicted coiled-coil fused to one of three output domains: PPM phosphatase (Gram positive bacteria), histidine protein kinase (Gram negative bacteria), and diguanylate cyclase (both lineages). Multiple alignment of the RsbP-PAS homologues suggested nine residues that distinguish the class. Alanine substitutions at four of these conferred a null phenotype in B. subtilis, indicating their functional importance. The F55A null substitution lay in the Fα helix of an RsbP-PAS model. F55A inhibited interaction of RsbP with RsbQ in yeast two-hybrid and pull-down assays but did not significantly affect interaction of RsbP with itself. We propose that RsbQ directly contacts the PAS domains of an RsbP oligomer to provide the activating signal, which is propagated to the phosphatase domains via the coiled-coil. A similar mechanism would allow the RsbQ-PAS module to convey a common input signal to structurally diverse output domains, controlling a variety of physiological responses

Use of the Ober2 system for analysis of eye movements made during reading

Introduction: The Ober2 system uses infrared reflections to record and analyze eye movements made during reading. The system\u27s ability to analyze data from normal subjects, and the reliability of the data produced by subjects who read standard paragraphs were investigated in this study. Subjects: Forty-two college students and 20 junior high students participated in the project. All were self-reported normal readers. Methods: Subjects read 5 different paragraphs during each of two sessions. Ober2 analysis was attempted for each paragraph; analysis of all 10 paragraphs was successful for 38 percent of the college subjects and 20 percent of the junior high subjects. Use of manual calibration procedures did not allow any additional data to be analyzed by the Ober2 system. Results: Data from 30% of the paragraph presentations could not be analyzed by the Ober2. When analysis was successful, grade equivalent scores based on fixations, span of recognition, regressions, fixation duration, and reading rate were provided. Using mean grade equivalents from the 16 college subjects for whom all 10 paragraphs could be analyzed, significant differences were found between results for two of the test paragraphs. Split-half reliability coefficients for grade equivalent data from the two sessions ranged from 0.84 to 0.95. Conclusions: Although the Ober2 can provide valuable information on eye movements made during reading, problems exist with respect to its ability to analyze data. The analysis failures that occurred for approximately one-third of the paragraph presentations were frustrating and time consuming. With respect to the standard paragraphs, significant grade equivalent differences were found between several of them. These results suggest that caution be used when interpreting data from the Ober2 reading analysis system