728 research outputs found
Viral marketing can be a safe bet
Today, from a business and marketing perspective, vast
numbers of customers and potential customers interact with
one another through electronic and online channels that range
from emails to social media hubs such as Facebook, MySpace
and Twitter
A Viral Branching Model for Predicting the Spread of Electronic Word-of-Mouth
In a viral marketing campaign an organization develops a marketing message, and stimulates customers to forward this message to their contacts. Despite its increasing popularity, there are no models yet that help marketers to predict how many customers a viral marketing campaign will reach, and how marketers can influence this process through marketing activities. This paper develops such a model using the theory of branching processes. The proposed Viral Branching Model allows customers to participate in a viral marketing campaign by 1) opening a seeding email from the organization, 2) opening a viral email from a friend, and 3) responding to other marketing activities such as banners and offline advertising. The model parameters are estimated using individual-level data that become available in large quantities already in the early stages of viral marketing campaigns. The Viral Branching Model is app
Novel application of local GAC adsorption to remove organic matters and pesticides in rural drinking water treatment
Novel application of granular activated carbon (GAC) using renewable and low cost materials to remove pesticides and organic matters was studied in the rural water treatment plant (WTP), in Hai Duong province, Vietnam. The treatment efficiencies of the a series of processes such as coagulation/ flocculation, horizontal sedimentation, rapid sand filtration and adsorption using three types of GAC (activated carbon from bituminous coal, from bamboo and from coconut shell) and the overall treatment trains were evaluated by studying several parameters such as turbidity, COD, pesticides (chlorpyrifos, diazinon, carbofuran). Results show that the two locally produced adsorbents have a similar efficiency to commercial activated carbon for adsorption. The removal efficiency was somewhat lower for both materials, but in the same order of magnitude. The removal of pesticides and organic matter with a column filled with activated carbon derived from bamboo was found the best among the two locally produced materials, approximately 30% and 23% higher than those observed for the column filled with activated carbon from coconut shells. It concludes that bamboo-derived activated carbon adsorption can be employed on an alternative to commercial activated carbon and could be a feasible option for drinking water treatment
Binary metal oxides for composite ultrafiltration membranes
A new ultrafiltration membrane was developed by the incorporation of binary metal oxides inside polyethersulfone. Physico-chemical characterization of the binary metal oxides demonstrated that the presence of Ti in the TiO2?ZrO2 system results in an increase of the size of the oxides, and also their dispersity. The crystalline phases of the synthesized binary metal oxides were identified as srilankite and zirconium titanium oxide. The effect of the addition of ZrO2 can be expressed in terms of the inhibition of crystal growth of anocrystalline TiO2 during the synthesis process. For photocatalytic applications the band gap of the synthesized semiconductors was determined, confirming a gradual increase (blue shift) in the band gap as the amount of Zr loading increases. Distinct distributions of binary metal oxides were found along the permeation axis for the synthesized membranes. Particles with Ti are more uniformly dispersed throughout the membrane cross-section. The physico-chemical characterization of membranes showed a strong correlation between some key membrane properties and the spatial particle distribution in the membrane structure. The proximity of metal oxide fillers to the membrane surface determines the hydrophilicity and porosity of modified membranes. Membranes incorporating binary metal oxides were found to be promising candidates for wastewater treatment by ultrafiltration, considering the observed improvement influx and anti-fouling properties of doped membranes. Multi-run fouling tests of doped membranes confirmed the stability of permeation through membranes embedded with binary TiO2?ZrO2 particles
Pressure-Corrected Carotid Stiffness and Young's Modulus: Evaluation in an Outpatient Clinic Setting
Background: Conventional measures for assessing arterial stiffness are inherently pressure dependent. Whereas statistical pressure adjustment is feasible in (larger) populations, it is unsuited for the evaluation of an individual patient. Moreover, statistical "correction"for blood pressure may actually correct for: (i) the acute dependence of arterial stiffness on blood pressure at the time of measurement; and/or (ii) the remodeling effect that blood pressure (hypertension) may have on arterial stiffness, but it cannot distinguish between these processes. METHODS: We derived - assuming a single-exponential pressure-diameter relationship - 3 theoretically pressure-independent carotid stiffness measures suited for individual patient evaluation: (i) stiffness index ÎČ0, (ii) pressure-corrected carotid pulse wave velocity (cPWVcorr), and (iii) pressure-corrected Young's modulus (Ecorr). Using linear regression analysis, we evaluated in a sample of the CATOD study cohort changes in mean arterial pressure (ÎMAP) and comparatively the changes in the novel (ÎÎČ0, ÎcPWVcorr, and ÎEcorr) as well as conventional (ÎcPWV and ÎE) stiffness measures after a 2.9 ± 1.0-year follow-up. RESULTS: We found no association between ÎMAP and ÎÎČ0, ÎcPWVcorr, or ÎEcorr. In contrast, we did find a significant association between ÎMAP and conventional measures ÎcPWV and ÎE. Additional adjustments for biomechanical confounders and traditional risk factors did neither materially change these associations nor the lack thereof. Conclusions: Our newly proposed pressure-independent carotid stiffness measures avoid the need for statistical correction. Hence, these measures (ÎČ0, cPWVcorr, and Ecorr) can be used in a clinical setting for (i) patient-specific risk assessment and (ii) investigation of potential remodeling effects of (changes in) blood pressure on intrinsic arterial stiffness
Nanofiltration of hormone mimicking trace organic contaminants
The removal mechanisms of three hormone mimicking organic compounds by nanofiltration (NF)
membranes have been examined. Two NF membranes having different pore size were used in
laboratory-scale nanofiltration experiments with feed solutions spiked with a hormone mimicking
compound Ÿ nonylphenol, tert-butyl phenol, or bisphenol A. Retention of the compounds was
determined at various solution chemistries, namely aqueous solution pH, ionic strength, and
presence of natural organic matter. The nanofiltration behavior of the selected hormone mimicking
compounds appears similar to that of natural hormones as reported in our previous work. While the
solution pH can dramatically influence the retention of hormone mimicking compounds by a loose
NF membrane, ionic strength does not affect the nanofiltration of such contaminants. However, in
the presence of natural organic matter in the feed solution, ionic strength appears to play a
significant role in solute-solute and solute-membrane interactions, resulting in increased retention
due to partitioning of the hormone mimicking compounds onto organic matter at a higher ionic
strength
Unique Roles of Mothering and Fathering in Child Anxiety; Moderation by Childâs Age and Gender
We examined the associations between the parenting dimensions autonomy granting, over control, and rejection and childrenâs anxiety, in relation to parent and child gender and child age. Elementary school-aged children (n = 179, Mage = 10.27, SD = 1.30), adolescents (n = 127, Mage = 15.02, SD = 1.54) and both their parents completed questionnaires on parenting and childrenâs anxiety. Parenting was more strongly related to child anxiety in elementary school children than in adolescents. Maternal over control was uniquely related to elementary school-aged childrenâs anxiety whereas paternal over control was more important during adolescence. Opposite to our expectations, we found higher levels of parental autonomy granting to be related to higher levels of anxiety for younger elementary school-aged children (age < 10). For adolescents, the association between paternal over control and anxiety was stronger for older adolescents (age > 15), with higher levels of over control related to higher levels of anxiety. For both elementary school-aged children and adolescents, the associations between parenting and child anxiety did not differ as a function of the childâs gender. If we are to understand the associations between parenting and childrenâs anxiety, it is important to distinguish parental autonomy granting from parental over control and to consider the role of parent gender and the age of the child
Challenges to the development of antigen-specific breast cancer vaccines
Continued progress in the development of antigen-specific breast cancer vaccines depends on the identification of appropriate target antigens, the establishment of effective immunization strategies, and the ability to circumvent immune escape mechanisms. Methods such as T cell epitope cloning and serological expression cloning (SEREX) have led to the identification of a number target antigens expressed in breast cancer. Improved immunization strategies, such as using dendritic cells to present tumor-associated antigens to T lymphocytes, have been shown to induce antigen-specific T cell responses in vivo and, in some cases, objective clinical responses. An outcome of successful tumor immunity is the evolution of antigen-loss tumor variants. The development of a polyvalent breast cancer vaccine, directed against a panel of tumor-associated antigens, may counteract this form of immune escape
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