Port Washington Public Library

Bots do not live in isolation. Companies and brands have invested significant time, energy, and money interacting with their customers via social media, such as Twitter, Facebook, Instagram, Snapchat, and others. There is an ongoing competition among social media companies to provide the best platform for businesses to interact with their customers. Each of these platforms wants to connect its users in the interest of driving platform usage and selling products. In addition, customer service systems from Zendesk, LiveChat, FreshDesk, and SericeNow, as well as tech behemoths like Oracle Service Cloud, Remedy, and Salesforce Service Cloud, are building up systems that connect consumers to a brand’s customer service representatives (CSRs) over all types of channels from SMS to Messenger to live chat.

[This corrects the article DOI: 10.3897/zookeys.717.21885.].

When asked by John Locke Scripps, a campaign biographer, about his childhood, Lincoln replied that it could be summed up in one line from Thomas Gray’s “Elegy in a Country Churchyard”—namely “‘the short and simple annals of the poor.’ That’s my life, and that’s all you or anyone else can make of it.” In the same doleful vein, Lincoln loved Poe’s “The Raven,” which he had memorized and recited often to companions during the years when he was riding the Eighth Court circuit in Illinois. These poems, along with Bryant’s “Thanatopsis” and a core of lyrics dealing with death, appealed to Lincoln’s dark, morbid streak, his vulnerability to depression. As Lincoln’s junior law partner William Herndon observed, “[M]elancholy dripped from him as he walked….His apparent gloom impressed his friends, and created sympathy for him—one means of his great success.

We investigated the effects of cellular aging on the expression of cementum and mineralization-specific proteins in human periodontal ligament (PDL) cells, since this is not well studied. Previously, we showed that STRO-1-and cementum protein 1 (CEMP1) -positive PDL cells behave like cementoblasts, since they can be directed toward cementogenesis. However, the mineralization characteristics of these cells during aging have not been examined. Thus, we examined mineralization and expression of the mineralization-related proteins, CEMP1, collagen I (COL I) and osteopontin (OPN) in STRO-1 positive selected and unselected human PDL cells, control human cementoblastoma cells, and human mesenchymal stem cells (hMSC). Early (young) and late (aged) passage cells were compared. Aged STRO-1 positive cells exhibited the highest level of mineralization as assessed by Alizarin red staining and energy dispersive x-ray spectroscopy. Aged STRO-1 positive PDL cells also exhibited high levels of CEMP1, OPN, and COL I expression at two weeks compared to all other cells. At earlier time points, osteogenic induction significantly enhanced CEMP1 expression in aged STRO-1 positive and parental PDL cells. In contrast, STRO-1 negative cells exhibited high CEMP1 expression only in young cells. High CEMP1 expression was also present in young cells derived from cementoblastoma cells and hMSC. Expression of OPN and COL I varied for STRO-1 negative PDL, cementoblastoma, and hMSC cells. In summary, cellular aging significantly promotes mineralization and expression of CEMP1, OPN, and COL I in STRO-1 positive PDL cells. These findings may impact periodontal tissue function and regeneration in the context of aging tissues.

Let M(n,k,r,s) be the number of ordered paths in the plane, with unit steps E or N, that intersect k times in which the first path ends at the point (r,n-r) and the second path ends at the point (s,n-s). Our main object of study in this paper is the sum of the numbers M(n,k,r,s) over r and s where r+s is fixed. We consider even and odd values of r+s separately, and we derive a simpler formula for M(n,k,r,s) than previously appeared in the literature.

An introduction to applied linguistics: from practice to theory, 2nd ed., by Alan Davies, Edinburgh, Edinburgh University Press, 2007, xiv + 199 pp., £55.00 (hardback), ISBN 978-0-7486-3354-8; £17....