Electronic Commerce Internet Strategies and Business Models-A Survey

Today, any doubts about possibilities of significant profits over the Internet are a distant memory. Such has been the proliferation of Internet-based business on the public network. But electronic commerce has turned out to be more difficult to master than previously assumed. For many, ventures have been less lucrative than expected. The problem is that integrating business models with technology is a multifaceted and largely open question (Shaw, et al. 1997). How do businesses of various sizes and industries actually start their Internet activity and how do their business models change over time? More specifically, how do their different Internet strategies play out? This article is the result of a survey of the Internet strategies and business models of 280 companies that sell products and services on the public network. The results show that electronic commerce has penetrated companies of all sizes. Based on this survey it is apparent that while many companies have participated in electronic commerce for years, their business models are still in their infancy stages.     

Negative peer reactions from the perspective of the reactor.

Conducted 2 studies to examine negative social reactions from the perspective of rejecting peers. The purpose of Study 1 was to test an attributional model of negative peer reactions in which perceptions of responsibility and specific emotions mediate between deviant peer characteristics and negative social responses. The more children perceived atypical classmates to be responsible for their idiosyncrasies, the more anger and less sympathy they reported. Anger increased rejection and decreased social support, whereas sympathy facilitated social support. In Study 2, the effects of responsibility perceptions and affective reactions (annoyance) on social responses were tested with an experimental design. Perceived responsibility influenced liking and support, whereas annoyance affected sympathy, support, and rejection. The results are discussed with respect to intervention programs that would improve children's social acceptance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of load on the tribological conditions in piston ring and cylinder liner contacts in a medium-speed diesel engine

The present work is an attempt to determine the oil film thickness in a medium-speed four-stroke diesel engine with a cylinder diameter of 200 mm. Experimental research on this topic was found necessary due to the limited amount of published information available with reference to engines of the present size. The experimental part of the study was carried out as firing engine tests, with an instrumented piston, equipped with telemetric data transmission, and an instrumented cylinder liner in a 6-in-line test engine. The study was carried out for different parts of the four-stroke working cycle and for different levels of engine power output. The results were compared with the results of computer simulations, carried out using a commercial software package. The conclusions of the study comprise aspects on the formation and development of the oil film between the rings and the liner under a set of load levels together with the periodical fluctuation during different strokes of the working cycle.     

Physically aggressive boys from ages 6 to 12: Family background, parenting behavior, and prediction of delinquency.

Boys from low socioeconomic environments were rated on physical aggression at ages 6, 10, 11, and 12 yrs by teachers and classified according to stability of fighting over time: stable high fighters, high fighters with late onset, desisting high fighters, variable high fighters, and nonfighters. The fighter groups differed from each other both in family background and parenting behavior. They were also significantly associated with delinquency across ages 10 to 14 yrs. A stepwise logistic regression with fighter groups, family adversity index, and parenting behavior variables as predictors showed that the Punishment?×?Fighter Group interaction, together with supervision, predicted self-reported delinquency. The study thus showed that the developmental pathways of physically aggressive behavior for boys in low socioeconomic environments were related to familial adversity and poor parenting, and that they predicted delinquency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative light-scattering angular correlations of conglomerate particles

A quantitative analysis of the fluctuations in the scattering associated with micrometer-size glycerol droplets that contain spherical latex inclusions are performed. Scattering intensities at two angles (the near-forward and the near-backward directions) are measured as functions of time. We analyze these signals using two techniques. We find that calculated autocorrelation time constants associated with these signals are not consistent with current models based on interference of light scattering from latex inclusions that exhibit Stokes-Einstein diffusion. The intensity fluctuations at different scattering angles display extended periods of both positive and negative correlations with characteristic time constants of the order of seconds. The time constants associated with the cross correlations provide information on the physical parameters of the inclusions.     

KLK3 in the Regulation of Angiogenesis—Tumorigenic or Not?

In this focused review, we address the role of the kallikrein-related peptidase 3 (KLK3), also known as prostate-specific antigen (PSA), in the regulation of angiogenesis. Early studies suggest that KLK3 is able to inhibit angiogenic processes, which is most likely dependent on its proteolytic activity. However, more recent evidence suggests that KLK3 may also have an opposite role, mediated by the ability of KLK3 to activate the (lymph)angiogenic vascular endothelial growth factors VEGF-C and VEGF-D, further discussed in the review.     

Upconversion fluorescence resonance energy transfer in a homogeneous immunoassay for estradiol

We recently described a novel homogeneous assay principle based on upconversion fluorescence resonance energy transfer (UC-FRET), where an upconverting phosphor (UCP) is utilized as a donor. The UC-FRET has now been applied to a competitive homogeneous immunoassay for 17beta-estradiol (E2) in serum, using a small-molecular dye as an acceptor. The assay was constructed by employing an UCP coated with an E2-specific recombinant antibody Fab fragment as a donor and an E2-conjugated small-molecular dye, Oyster-556, as an acceptor. Standard curves for the assay were produced both in buffer and in male serum. Sensitized acceptor emission was measured at 600 nm under continuous laser diode excitation at 980 nm. In buffer, the IC50 value of the assay was 1 nM and in serum 3 nM. The lower limits of detection (mean of zero calibrators, 3 SD) were 0.4 and 0.9 nM, respectively. The measurable concentration range extended up to 3 nM in buffer and 9 nM in serum. Equilibrium in the assay was reached in 30 min. The novel principle of UC-FRET has unique advantages compared to present homogeneous luminescence-based methods and can enable an attractive assay system platform for clinical diagnostics and for high-throughput screening approaches.     

In vitro fermentation of cereal dietary fibre carbohydrates by probiotic and intestinal bacteria

A range of probiotic and other intestinal bacteria were examined for their ability to ferment the dietary fibre carbohydrates β‐glucan, xylan, xylo‐oligosaccharides (XOS) and arabinoxylan. β‐Glucan was fermented by Bacteroides spp and Clostridium beijerinckii but was not fermented by lactobacilli, bifidobacteria, enterococci or Escherichia coli. Unsubstituted xylan was not fermented by any of the probiotic bacteria examined. However, many Bifidobacterium species and Lactobacillus brevis were able to grow to high yields using XOS. XOS were also efficiently fermented by some Bacteroides isolates but not by E coli, enterococci, Clostridium difficile, Clostridium perfringens or by the majority of intestinal Lactobacillus species examined. Bifidobacterium longum strains were able to grow well using arabinoxylan as the sole carbon source. These organisms hydrolysed and fermented the arabinosyl residues from arabinoxylan but did not substantially utilise the xylan backbone of the polysaccharide. Arabinoxylan was not fermented by lactobacilli, enterococci, E coli, C perfringens or C difficile and has potential to be an applicable carbohydrate to complement probiotic Bif longum strains in synbiotic combinations. © 2002 Society of Chemical Industry     

Graphitic Carbon in Snow

We collected several samples of fresh snow from the areas of southern New Mexico and western Texas. Samples were analyzed to determine graphitic carbon content of snow in rural and urban areas and to compare these present values with those obtained from deep ice core samples several thousand years old. To model the optical properties of snow grains containing carbon we used several different versions of effective medium approximations. Calculations are compared with microwave analog measurements to determine which of these approximations can reasonably well predict the properties of mixtures such as snow and carbon. Suggestions regarding which of the effective medium approximations that should not be used are presented.