Engaging with charities on social media: comparing interaction on Facebook and Twitter

Social media are commonly assumed to provide fruitful online communities for organisations, whereby the brand and supporter-base engage in productive, two-way conversations. For charities, this provides a unique opportunity to reach an audience for a relatively low cost, yet some remain hesitant to fully embrace these services without knowing exactly what they will receive in return. This paper reports on a study that seeks to determine the extent to which these conversations occur, and compares this phenomenon on Facebook and Twitter for a sample of UK-based charities. Focus was placed on analysing conversations as signs of developing relationships, which have previously been shown to be a key target for charities on social media. The results of this study find that while there is an expected proportion of the audience who prefer to listen rather than engage, there is strong evidence of a core group of supporters on each site who repeatedly engage. Interestingly, disparities between how this occurs on Facebook and Twitter emerge, with the results suggesting that Facebook receives more conversations in response to the charities’ own posts, whereas on Twitter there is a larger observable element of unsolicited messages of people talking about the charity, which in turn produces a differing opportunity for the charity to extract value from the network. It is also found that posts containing pictures receive the highest number of responses on each site. These were a lot less common on Twitter and could therefore offer an avenue for charities to increase the frequency of responses they achieve

Novel morphologic and genetic analysis of cancer cells in a 3D microenvironment identifies STAT3 as a regulator of tumor permeability barrier function

Tumor permeability is a critical determinant of drug delivery and sensitivity, but systematic methods to identify factors that perform permeability barrier functions in the tumor microenvironment are not yet available. Multicellular tumor spheroids have become tractable in vitro models to study the impact of a three-dimensional (3D) environment on cellular behavior. In this study, we characterized the spheroid-forming potential of cancer cells and correlated the resulting spheroid morphologies with genetic information to identify conserved cellular processes associated with spheroid structure. Spheroids generated from 100 different cancer cell lines were classified into four distinct groups based on morphology. In particular, round and compact spheroids exhibited highly hypoxic inner cores and permeability barriers against anticancer drugs. Through systematic and correlative analysis, we reveal JAK-STAT signaling as one of the signature pathways activated in round spheroids. Accordingly, STAT3 inhibition in spheroids generated from the established cancer cells and primary glioblastoma patient-derived cells altered the rounded morphology and increased drug sensitivity. Furthermore, combined administration of the STAT3 inhibitor and 5-fluorouracil to a mouse xenograft model markedly reduced tumor growth compared with monotherapy. Collectively, our findings demonstrate the ability to integrate 3D culture and genetic profiling to determine the factors underlying the integrity of the permeability barrier in the tumor microenvironment, and may help to identify and exploit novel mechanisms of drug resistance. © 2015 American Association for Cancer Research1771sciescopu

First-principles study of bulk and surface oxygen vacancies in SrTiO 3 crystal

61.72.jd Vacancies, 71.15.Ap Basis sets and related methodology, 61.72.jn Color centers,