Do Exclusivity Arrangments Harm Consumers?

This paper explores welfare implications of exclusivity arrangements, e.g. iPhone?s part- nership with wireless carriers. Two ?rms compete in a primary good market, while a monop- olistic ?rm o¤ers a value-adding good. The primary good can be consumed alone, while the value-adding good must be consumed with the primary good. The monopolistic ?rm forms an exclusivity partnership with one of the primary good providers. Buyers are able to consume the value-adding good only if they patronize the monopolistic ?rm?s exclusive partner. This practice allows the monopolistic ?rm to extract surplus from the primary good market. Sur- prisingly, consumers bene?t from the exclusivity arrangement. However, overall social welfare declines, despite improvements to consumer welfare.exclusivity, consumer welfare, market efficiency, hotelling

Political Polarization and Price Dispersion: Recent Evidence from the Airline Industry During COVID-19

This paper analyzes the relationship between price dispersion and political polarization of the endpoint states on a given route during the COVID-19 pandemic. The sample includes ticket information from the DB1B database between 2020:Q1 and 2021:Q4. The fixed-effect panel instrument variable (IV) estimation finds evidence of increased price dispersion on routes connecting states led by a Republican governor than those linking Democrat-led states. My analysis adds to the literature by exploiting the impact of political factors (i.e. demand shocks triggered by the COVID-19 policy interventions) on price dispersion using the latest data

Decoupling of nutrient stoichiometry in Suaeda glauca (Bunge) senesced leaves under salt treatment

The stoichiometry of senesced leaves is pivotal in nutrient cycling and can be significantly influenced by soil salinization, a rising global issue threatening the functionality of ecosystems. However, the impacts of soil salinization on senesced leaf stoichiometry are not fully understood. In this study, we conducted a pot experiment with varying soil salt concentrations to examine their influence on the concentrations and stoichiometric ratios of nitrogen (N), phosphorus (P), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), and zinc (Zn) in the senesced leaves of Suaeda glauca (Bunge). Compared to the control group, salt treatments significantly enhanced Na concentration while diminishing the concentrations of K, Ca, Mg, Zn, N, and P. Interestingly, as salinity levels escalated, N concentration maintained stability, whereas P concentration exhibited an increasing trend. Moreover, K, Ca, and Mg significantly declined as salt levels rose. Salt treatments brought about significant changes in stoichiometric ratios, with the N:P, K:Na, N:Na, N:Mg, and Ca : Mg ratios dropping and the N:Ca and N:K ratios rising, illustrating the varying nutrient coupling cycles under different salt conditions. These findings shed light on the plasticity of stoichiometric traits in S. glauca senesced leaves in response to soil salinization shifts, which could potentially offer insights into nutrient cycling reactions to soil salinization

Where do new Ph.D. economists go? Evidence from recent initial job placements

We use data from the 2007-2008 Ph.D. economist job market to investigate initial job placement in terms of job location, job type, and job rank. Our results suggest gender differences in all three dimensions of job placement. Relative to their male counterparts, female candidates are less (more) likely to be placed into academic (government or private sector) jobs and, on average, are placed into worse ranked jobs. Foreign female candidates are also more likely than foreign males to stay in the U.S. When foreign students are placed outside the U.S., they are more likely to be in academia than in government or private sector, while the opposite holds when foreign students are placed in the U.S., which is largely consistent with a stylized theory model. Our results also reveal various country/region heterogeneities in the type, location, and rank of job placements

Evaluation of spatial active noise cancellation performance using spherical harmonic analysis

This paper presents a novel metric to evaluate the performance of spatial active noise cancellation (ANC) systems. We show that the acoustic potential energy within a spherical region can be expressed by a weighed squared sum of spherical harmonic coefficients. The proposed metric allows convenient evaluation of spatial ANC performance using a spherical microphone array. In order to evaluate the effectiveness of this metric, we set up a experimental ANC system and conducted a series narrow band and wide band ANC experiments, the results show that the proposed potential energy method provides a reliable characterization of the performance of spatial ANC systems.This work is supported by Australian Research Council (ARC) Discovery Projects funding scheme (project no. DP140103412)

Influences of nitrogen input forms and levels on phosphorus availability in karst grassland soils

The availability of soil phosphorus (P), a crucial nutrient influencing plant productivity and ecosystem function, is impacted by continuously increasing nitrogen (N) enrichment, which changes the soil P cycle. The effect of varying forms of N input on soil P dynamics in P-limited karst grassland ecosystems remains unclear. To address this knowledge gap, we conducted a greenhouse experiment to explore the effects of various forms of N addition [Ca(NO3)2, NH4Cl, NH4NO3, Urea] on soil P fractions in these ecosystems, applying two levels (N1: 50 mg N kg−1soil, N2: 100 mg N kg−1soil) of N input in two soils (yellow soil, limestone soil). Results indicated that P fractions in both soil types were significantly affected by N additions, with yellow soil demonstrating a higher sensitivity to these additions, and this effect was strongly modulated by the form and level of N added. High N addition, rather than low N, significantly affect the P fractions in both soil types. Specially, except for Ca(NO3)2, high N addition significantly increased the available P in both soils, following the order: Urea and NH4NO3 > NH4Cl > Ca(NO3)2, and decreased NaHCO3-Pi in both soils. High N addition also significantly reduced NaOH-Po and C.HCl-Po fractions in yellow soil. Additionally, the response of root biomass and alkaline phosphatase activity in both soils to N input paralleled the trends observed in the available P fractions. Notably, changes in soil available P were strongly correlated with plant root biomass and soil alkaline phosphatase activity. Our study highlights that the N addition form significantly influences soil P availability, which is closely tied to plant root biomass and alkaline phosphatase activity. This finding underscores the importance of considering N input form to boost soil fertility and promote sustainable agriculture

Evolution of H9N2 influenza viruses from domestic poultry in Mainland China

AbstractH9N2 viruses have circulated in domestic poultry in Mainland China since 1994, and an inactivated vaccine has been used in chickens to control the disease since 1998. The present study analyzed 27 H9N2 avian influenza viruses that were isolated from chickens and ducks from 1996 to 2002. Infection studies indicated that most of the viruses replicate efficiently but none of them is lethal for SPF chickens. However, these viruses exhibit different phenotypes of replication in a mouse model. Five viruses, including 4 early isolates and one 2000 isolate, are not able to replicate in mice; 14 viruses replicate to moderate titers in mouse lungs and cause less than 5% weight loss, while other 8 viruses could replicate to high titers in the lungs and 7 of them induce 10–20% weight loss of the mice on day 5 after inoculation. Most of the viruses isolated after 1996 are antigenically different from the vaccine strain that is currently used in China. Three viruses isolated in central China in 1998 are resistant to adamantanes. Phylogenetic analysis revealed that all of the viruses originated from CK/BJ/1/94-like virus and formed multiple genotypes through complicated reassortment with QA/HK/G1/97-, CK/HK/G9/97-, CK/SH/F/98-, and TY/WI/66-like viruses. This study is a description of the previously uncharacterized H9N2 avian influenza viruses recently circulating in chickens and ducks in Mainland China. Our findings suggest that urgent attention should be paid to the control of H9N2 influenza viruses in animals and to the human's influenza pandemic preparedness

High‐Performance Pseudocubic Thermoelectric Materials from Non‐cubic Chalcopyrite Compounds

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107585/1/adma201400058-sup-0001-S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/107585/2/adma201400058.pd

Allergen Delivery Inhibitors: Characterisation of Potent and Selective Inhibitors of Der p 1 and Their Attenuation of Airway Responses to House Dust Mite Allergens

Group 1 allergens of house dust mites (HDM) are globally significant triggers of allergic disease. They are considered as initiator allergens because their protease activity enables the development of allergy to a spectrum of unrelated allergens from various sources. This initiator-perpetuator function identifies Group 1 HDM allergens as attractive drug design targets for the first small-molecule approach directed towards a non-human, root cause trigger of allergic disease. The purpose of this study was to: (i) identify exemplar inhibitors of these allergens using Der p 1 as a design template, and (ii) characterise the pharmacological profiles of these compounds using in vitro and in vivo models relevant to allergy. Potent inhibitors representing four different chemotypes and differentiated by mechanism of action were investigated. These compounds prevented the ab initio development of allergy to the full spectrum of HDM allergens and in established allergy they inhibited the recruitment of inflammatory cells and blunted acute allergic bronchoconstriction following aerosol challenge with the full HDM allergen repertoire. Collectively, the data obtained in these experiments demonstrate that the selective pharmacological targeting of Der p 1 achieves an attractive range of benefits against exposure to all HDM allergens, consistent with the initiator-perpetuator function of this allergen

Peptidomics approaches to the discovery and ACE inhibitory effect of casein peptides derived from fermented bovine milk by kefir grains

IntroductionKefir grains with efficient proteolytic system is an excellent starter culture for the production of bioactive peptides and milk products. This study explores the casein peptides derived from fermented bovine milk by kefir grains using the peptidomics approaches. The angiotensin converting enzyme (ACE) inhibitory activity of these peptides were also investigated.MethodsAfter fermentation, peptidomics based on the LC-MS/MS was used to investigate the dynamic profile and the structure specificity of generated peptides. The ACE inhibitory activity of peptides was determined by measuring the amount of hippuric acid (HA) by a spectrophotometer at 228 nm.ResultsThe results indicated that the cell envelope proteinases (CEPs) were the PI-/PIII-type. A total of 122 peptides were identified. The β-casein was preferentially hydrolyzed by kefir grains, and the main hydrolysis regions were f57-93, f132-160 and f192-209. The αs1-, and κ-casein were also hydrolyzed by a weaker degree. In the process of fermentation, the accumulated peptides increased with the fermentation time. The fermentation products exhibited ACE inhibitory activity, and this bioactivity remained 63% after simulated gastrointestinal (GI) digestion in vitro. Additionally, 14 Pro-containing peptides with ACE inhibitory activity were also identified.ConclusionThese results provide new insights and evidence to investigate the bioactive milk peptides generated by kefir grains fermentation, as well as a reference for the development of functional foods