Beyond the more the merrier: The variety effect and consumer heterogeneity in system markets

© 2015 Elsevier B.V. Research in indirect network effects has simplistically treated complementary product variety as the total number of complementary products (e.g., game titles in video game markets). This assumption of equi-differentiation ignores differences across genres or product categories. Furthermore, since consumers with differential preferences for variety enter the market at different stages, consumer heterogeneity in preference for variety in complementary products may evolve as the market develops. We propose a model that recognizes these previously ignored, but important, demand characteristics, and empirically investigate the effects of breadth and depth of software variety on consumer hardware adoption in the fifth-generation video game market. We find that early adopters seek variety across a wide spectrum of game genres, and that late adopters are interested only in action-oriented games and have no interest in strategy-oriented games unless they are so-called superstars. Our findings imply that effective variety planning should be built along both dimensions, instead of simply assuming that more is better. Our policy simulations demonstrate that variety planning is as critical as entry timing to the success of platform companies in system competition, and is one of the reasons for PlayStation\u27s winning the battle against Nintendo64. In addition, the boosting effect of a new title on hardware sales perishes quickly, so it is important to have a cascade strategy to guarantee a continuous supply of complementary software

Structural examination of historical heritage bridges

Culture and heritage are important aspects of a civilization after meeting basic needs. The heritage structures also called monuments are generally quite old and may be ever older than hundred years. In case of bridges, the life span as stated by codes/ standards is 50 years to 75 years. Further, the material used in heritage structures are unique in sense the composition at the time of construction is generally not available. Therefore, it is a challenging task to assess the performance of the heritage structures including bridges. In this respect, some of the heritage bridge s in Delhi have been studied and results of one bridge connecting the Red fort and Salimgarh fort namely Mangi Bridge are discussed. The methodology of study involves collection of site data (geometry), numerical modelling, experimental studies at the site and useful inferences. The vibration study and the ongoing traffic affects the bridge as the bridge lies on the major arterial road called Ring Road in Delhi. The study will be helpful for continued use of the bridge

Structural examination of historical heritage bridges

76-79Culture and heritage are important aspects of a civilization after meeting basic needs. The heritage structures also called monuments are generally quite old and may be ever older than hundred years. In case of bridges, the life span as stated by codes/ standards is 50 years to 75 years. Further, the material used in heritage structures are unique in sense the composition at the time of construction is generally not available. Therefore, it is a challenging task to assess the performance of the heritage structures including bridges. In this respect, some of the heritage bridge s in Delhi have been studied and results of one bridge connecting the Red fort and Salimgarh fort namely Mangi Bridge are discussed. The methodology of study involves collection of site data (geometry), numerical modelling, experimental studies at the site and useful inferences. The vibration study and the ongoing traffic affects the bridge as the bridge lies on the major arterial road called Ring Road in Delhi. The study will be helpful for continued use of the bridge

Type IIA2 urethral duplication: Report of an unusual case

Objective This report describes a rare case of type IIA2 sagittal urethral   duplication. Summary background data The presentation, investigation, and  management of this rare anomaly are briefly discussed.Methods A 3½-year-old boy presented with urinary obstruction and recurrent urinary tract infection due to a stenosed dorsal urethra and segmental stenosis of the dominant ventral urethra. The child also had left-sided vesicoureteric reflux. Staged surgical management consisted of an initial vesicostomy followed by serial dilatation of the ventral urethral stricture, left ureteric reimplantation, and a 2-cm long distal urethrourethrostomy between the dorsal urethra, opening at the tip of the penis, and the ventral urethra, which had a hypospadic opening at the base of the glans.Results The functional and cosmetic outcomes were satisfactory.Conclusion The management needs to be individualizedas best suited for the patient.Keywords: urethra, urethral duplication, urethral strictur

Type IIA2 urethral duplication: report of an unusual case

This report describes a rare case of type IIA2 sagittal urethral duplication. The presentation, investigation, and management of this rare anomaly are briefly discussed. A 3½-year-old boy presented with urinary obstruction and recurrent urinary tract infection due to a stenosed dorsal urethra and segmental stenosis of the dominant ventral urethra. The child also had left-sided vesicoureteric reflux. Staged surgical management consisted of an initial vesicostomy followed by serial dilatation of the ventral urethral stricture, left ureteric reimplantation, and a 2-cm long distal urethrourethrostomy between the dorsal urethra, opening at the tip of the penis, and the ventral urethra, which had a hypospadic opening at the base of the glans. The functional and cosmetic outcomes were satisfactory. The management needs to be individualized as best suited for the patient.Keywords: urethra, urethral duplication, urethral strictur

Dip coating of forsterite-hydroxyapatitie-poly (ɛ-caprolactone) nanocomposites on Ti6Al4Vsubstrates for its corrosion prevention

522-528Titanium and titanium alloys are extensively used in biomedical, cardiac and cardiovascular applications for their superb properties, such as good fatigue strength, low modulus, machinability, formability, corrosion resistance and biocompatibility. However, titanium and its alloys do not meet the majority of all clinical necessities. Due to these reasons, surface modification is frequently performed to enhance the mechanical, biological and chemical properties of titanium and alloys. In this work, nanocomposites coating of poly(ɛ-caprolactone)/hydroxyapatite/forsterite (PCL/HA/F) have been successfully deposited on the Ti6Al4V substratesby dip coating at room temperature. The coatings are prepared with various concentrations of forsterite/hydroxyapatite nanopowder (2, 4, 6 and 8 wt.%) with a fixed concentration of PCL (4 wt.%) and thus coated Ti6Al4V substrates are examined for corrosion resistance. PCL/Hydroxyapatite/Forsterite coatings are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), which clearly showed the formation of nanocomposites. Potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) are used to investigate corrosion behavior of the coated substrates, which portrayed that the composite coating of PCL/HA/F substantially enhanced the corrosion resistance of Ti6Al4V alloy

Dip coating of forsterite-hydroxyapatitie-poly (ɛ-caprolactone) nanocomposites on Ti6Al4Vsubstrates for its corrosion prevention

Titanium and titanium alloys are extensively used in biomedical, cardiac and cardiovascular applications for their superb properties, such as good fatigue strength, low modulus, machinability, formability, corrosion resistance and biocompatibility. However, titanium and its alloys do not meet the majority of all clinical necessities. Due to these reasons, surface modification is frequently performed to enhance the mechanical, biological and chemical properties of titanium and alloys. In this work, nanocomposites coating of poly(ɛ-caprolactone)/hydroxyapatite/forsterite (PCL/HA/F) have been successfully deposited on the Ti6Al4V substratesby dip coating at room temperature. The coatings are prepared with various concentrations of forsterite/hydroxyapatite nanopowder (2, 4, 6 and 8 wt.%) with a fixed concentration of PCL (4 wt.%) and thus coated Ti6Al4V substrates are examined for corrosion resistance. PCL/Hydroxyapatite/Forsterite coatings are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), which clearly showed the formation of nanocomposites. Potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) are used to investigate corrosion behavior of the coated substrates, which portrayed that the composite coating of PCL/HA/F substantially enhanced the corrosion resistance of Ti6Al4V alloy

Longlasting insecticidal nets for prevention of Leishmania donovani infection in India and Nepal: paired cluster randomised trial

Objective To test the effectiveness of large scale distribution of longlasting nets treated with insecticide in reducing the incidence of visceral leishmaniasis in India and Nepal