Durable-Goods Monopolists, Network Effects and Penetration Pricing

We study the pricing problem of a durable-goods monopolist. With network effects, consumption externalities among heterogeneous groups of consumers generate a discontinuous demand function. Consequently, the lessor has to offer a low price in order to reach the mass market, whereas the seller has the option to build a customer base by setting a lower initial price and raise the price later in the mass market, which explains the practice of introductory pricing. Contrary to the existing literature, we show that profits from selling network goods may be higher than from leasing. Further, the seller in fact over-invests in R&D and makes the product more durable than necessary.Penetration pricing, network externality

Bracketing in Phenomenology: Only Undertaken in the Data Collection and Analysis Process

Our aim with this article is to demonstrate how the researchers use bracketing as a method of demonstrating the validity after initiating a phenomenological study. Although bracketing is a method of demonstrating the validity of the da ta collection and analysis process in most phenomenological studies, how the researchers use them in practice is rarely demonstrated explicitly. We collected data through our experiences in preparing a phenomenological research study. We suggest that the concept of bracketing should be adopted upon initiating the research proposal and not merely in the data collection and analysis process. We propose four strategies for doing bracketing that are guided by the thinking activity of reflexivity: mentality assessment and preparation before deciding the research paradigm, deciding the scope of the literature review according to the prevailing gate - keeping policy, planning for data collection using semi - structured interviews guided by open - ended questions, and planning for data analysis using Colaizzi’s method. Our proposition highlights that thorough preparation for doing bracketing is essential before entering the data collection and analysis process in phenomenology, because they are sequentially related

The Evolutionary Theory of Time Preferences and Intergenerational Transfers

At each age an organism produces energy by foraging and allocates this energy among reproduction, survival, growth, and intergenerational transfers. We characterize the optimal set of allocation decisions that maximizes reproductive fitness. Time preference (the discount rate) is derived from the marginal rate of substitution between energy obtained at two different times or ages in an individual’s life, holding reproductive fitness constant. We show that the life history may have an initial immature phase during which there is body growth but no fertility, and a later mature phase with fertility but no growth, as with humans. During the immature phase, time preference depends only on the compounding effect of body growth, much like returns on a capital investment, but not on fertility, or the intrinsic population growth rate. During the mature phase, time preference depends on the costliness of fertility, and on endogenous survival and intrinsic growth rate, and not at all on body growth. During the transition between the two phases, fertility, mortality, body growth, and intrinsic growth rate all matter. Using these results, we conclude that time preference and discount rates are likely to be U-shaped across age. We compare our results to Hansson and Stuart (1990), Rogers (1994, 1997) and Sozou and Seymour (2003). Wastage and inefficiencies aside, in a single sex model a system of intergenerational transfers yields Samuelson’s (1958) biological interest rate equal to the population growth rate. When the rate of time preference exceeds this biological rate, inter- generational transfers will raise fitness and evolve through natural selection, partially smoothing out the age variations in time preference.

Translation and Validation of the Chinese ICD-11 International Trauma Questionnaire (ITQ) for the Assessment of Posttraumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD)

Background: Two stress-related disorders have been proposed for inclusion in the revised ICD-11: Posttraumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD). The International Trauma Questionnaire (ITQ) is a bespoke measure of PTSD and CPTSD and has been widely used in English-speaking countries. Objective: The primary aim of this study was to develop a Chinese version of the ITQ and assess its content, construct, and concurrent validity. Methods: Six mental health practitioners and experts rated the Chinese translated and back-translated items to assess content validity. A sample of 423 Chinese young adults completed the ITQ, the WHO Adverse Childhood Experiences International Questionnaire, and the Hospital Anxiety and Depression Scale. Among them, 31 participants also completed the English and Chinese versions of the ITQ administered in random order at retest. Four alternative confirmatory factor analysis models were tested using data from participants who reported at least one adverse childhood experience (ACE; N = 314). Results: The Chinese ITQ received excellent ratings on relevance and appropriateness. Test–retest reliability and semantic equivalence across English and Chinese versions were acceptable. The correlated first-order six-factor model and a second-order two-factor (PTSD and DSO) both provided an acceptable model fit. The six ITQ symptoms clusters were all significantly correlated with anxiety, depression, and the number of ACEs. Conclusions: The Chinese ITQ generates scores with acceptable psychometric properties and provides evidence for including PTSD and CPTSD as separate diagnoses in ICD-11

Indenopyridine hydrochloride induced testicular spermatogenesis failure with high seminal alkaline phosphatase levels in male dog

Indenopyridine hydrochloride (IH), an antispermatogenic agent, was tested to determine the testicular pathological changes, seminal spermatozoa concentrations and seminal plasma alkaline phosphatase levels in male dogs. A single oral dosage of 30 mg IH/kg BW induced the dissociation and premature release of germ cells into the lumens of seminiferous tubules. Ring-shaped spermatid nuclei, nuclear pykonosis of spermatocytes and multinucleated cell associations were also observed. Thereafter, the spermatogenic index (SI) significantly decreased one day after IH administration. Moreover, seminal spermatozoa concentrations decreased two weeks after drug treatment; and there was a statistically significant difference in spermatozoa production inhibited by IH compared to the control. Reversible spermatogenesis was noted 7 weeks after IH treatment in male dogs. Meanwhile, seminal plasma alkaline phosphatase levels also significantly increased two weeks after IH treatment. These data confirm that IH might induce a two-month inhibition of spermatogenesis in male dogs

A comparison between yellow-green and green cultivars of four vegetable species in pigments, ascorbate, photosynthesis, energy dissipation, and photoinhibition

Yellow-green foliage cultivars of four vegetables grown outdoors, i.e., Chinese mustard (Brassica rapa), Chinese kale (Brassica oleracea var. alboglabra), sweet potato (Ipomoea batatas) and Chinese amaranth (Amaranthus tricolor), had lower chlorophyll (Chl) (a+b) (29-36% of green cultivars of the same species), total carotenoids (46-62%) and ascorbate (72-90%) contents per leaf area. Furthermore, yellow-green cultivars had smaller photosystem II (PSII) antenna size (65-70%) and lower photosynthetic capacity (52-63%), but higher Chl a/b (107-156%) and from low (60%) to high (129%) ratios of de-epoxidized xanthophyll cycle pigments per Chl a content. Potential quantum efficiency of PSII (F(v)/F(m)) of all overnight dark-adapted leaves was ca. 0.8, with no significant difference between yellow-green and green cultivars of the same species. However, yellow-green cultivars displayed a higher degree of photoinhibition (lower F(v)/F(m) after illumination) when they were exposed to high irradiance. Although vegetables used in this study are of either temperate or tropical origin and include both C(3) and C(4) plants, data from all cultivars combined revealed that F(v)/F(m) after illumination still showed a significant positive linear regression with xanthophyll cycle-dependent energy quenching (q(E)) and a negative linear regression with photoinhibitory quenching (q(I)). F(v)/F(m) was, however, not correlated with nonphotochemical quenching (NPQ). Yet, a higher degree of photoinhibition in yellow-green cultivars could recover during the night darkness period, suggesting that the repair of PSII in yellow-green cultivars would allow them to grow normally in the field

Neutrino flux calculations for the AGS narrow band beam

Presented are results of calculations of nu/sub ..mu../ fluxes in the AGS neutrino beam with the new dichromatic horn. The wide band beam nu/sub ..mu../, as well as the nu/sub e/ backgrounds, are discussed. The nu/sub e//nu/sub ..mu../ ratio is about 8 x 10/sup -3/. The possible sources and magnitudes of uncertainties are discussed. Finally, the calculated fluxes are compared with beam measurements

Hybrid bubble chamber studies of K+ p and K- p interactions at 75-GeV/c

We propose to expose the FNAL 30' liquid hydrogen bubble chamber to K{sup +} and K{sup -} beams both at 75 GeV/c. Each exposure consists of 100,000 equivalent K pictures. We plan to use the upstream tagging system currently in place and a downstream spectrometer with acceptance considerably increased over that of the current PHC system. This new downstream system will also be equipped with a lead glass photon detector with good spatial and energy resolution. We will study comparison of K{sup +} and K{sup -} results, as well as results from {pi}{sup +}, {pi}{sup -} , and {bar p} beams at this energy which are the subject of separate proposals

Galaxy Clusters Associated with Short GRBs. II. Predictions for the Rate of Short GRBs in Field and Cluster Early-Type Galaxies

We determine the relative rates of short GRBs in cluster and field early-type galaxies as a function of the age probability distribution of their progenitors, P(\tau) \propto \tau^n. This analysis takes advantage of the difference in the growth of stellar mass in clusters and in the field, which arises from the combined effects of the galaxy stellar mass function, the early-type fraction, and the dependence of star formation history on mass and environment. This approach complements the use of the early- to late-type host galaxy ratio, with the added benefit that the star formation histories of early-type galaxies are simpler than those of late-type galaxies, and any systematic differences between progenitors in early- and late-type galaxies are removed. We find that the ratio varies from R(cluster)/R(field) ~ 0.5 for n = -2 to ~ 3 for n = 2. Current observations indicate a ratio of about 2, corresponding to n ~ 0 - 1. This is similar to the value inferred from the ratio of short GRBs in early- and late-type hosts, but it differs from the value of n ~ -1 for NS binaries in the Milky Way. We stress that this general approach can be easily modified with improved knowledge of the effects of environment and mass on the build-up of stellar mass, as well as the effect of globular clusters on the short GRB rate. It can also be used to assess the age distribution of Type Ia supernova progenitors.Comment: ApJ accepted versio

Alignment of the CMS silicon tracker during commissioning with cosmic rays

This is the Pre-print version of the Article. The official published version of the Paper can be accessed from the link below - Copyright @ 2010 IOPThe CMS silicon tracker, consisting of 1440 silicon pixel and 15 148 silicon strip detector modules, has been aligned using more than three million cosmic ray charged particles, with additional information from optical surveys. The positions of the modules were determined with respect to cosmic ray trajectories to an average precision of 3–4 microns RMS in the barrel and 3–14 microns RMS in the endcap in the most sensitive coordinate. The results have been validated by several studies, including laser beam cross-checks, track fit self-consistency, track residuals in overlapping module regions, and track parameter resolution, and are compared with predictions obtained from simulation. Correlated systematic effects have been investigated. The track parameter resolutions obtained with this alignment are close to the design performance.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)