The Effect of Emdogain Periodontal Regenerative Material on Inflammation in Periodontal Maintenance Patients

The purpose of this double-blinded, randomized, controlled clinical trial was to determine if local application of enamel matrix protein derivative (Emdogain:EMD), combined with minimally-invasive papilla reflection is effective in reducing inflammation in periodontal pockets in patients on periodontal maintenance therapy (PMT).Fifty patients diagnosed with advanced chronic periodontitis presenting with a 6-9mm interproximal probing depth were included in the trial. Experimental (EMD; n=24) and control (saline, n=26) therapies were randomly allocated. Roots were treated with mini-flaps and root planing assisted with endoscope evaluation before EMD or saline application. Inflammation was assessed by bleeding on probing (BOP) at baseline, 6-, and 12-months and gingival crevicular fluid (GCF) samples at baseline, 2-weeks, 6-, and 12-months. GCF was evaluated for change in IL-1β and PGE2 levels using ELISA. A significant reduction in BOP at the treatment site was seen for both groups after 12-months. After adjustments, patients with BOP present at baseline had a higher risk of a poor BOP outcome at 12-months (AOR = 5.68, p = 0.048). At 2-weeks, there was a significant reduction in IL-1β with EMD (mean = -40.15 pg, p = 0.05) and at 12-months a trend for reduction in IL-1β with EMD (mean = -32.85 pg, p = 0.07). Differences in IL-1β between groups were not significant. The addition of EMD does not significantly improve BOP; however, EMD does significantly decrease IL-1β in the short-term compared to a control in periodontal maintenance patients

Pre-service students understanding of professional roles

This study aims to begin understanding how well pre-service speech-language pathologists and teachers understand their roles in collaboration in the schools. Data were collected from a survey completed by undergraduate and graduate students in the Communication Sciences and Disorders and Education departments at one middle-sized university in the Midwest. Results indicated a wide range of understanding and preparedness. Several themes emerged as to what students feel confident about in terms of collaboration, as well as what they believe they still need to learn before they can be confident in collaborating in the schools. The data provides insight into what pre-service students see collaboration involving, as well as what educational institutions can do to help students feel more prepared for future collaboration in the schools between teachers and speech-language pathologists

The variable effect of form and lemma frequencies on phonetic variation: evidence from /s/ realization in two varieties of Colombian Spanish

Research has shown that frequency conditions the variable realization of sounds. However, the literature has not addressed whether the frequency of the individual word forms, or form frequency, has a larger conditioning effect than the combined frequencies of the members of the paradigm to which the forms belong, or lemma frequency. Monofactorial correlation tests and monofactorial and multifactorial linear regression analyses are performed on 2,734 tokens of Spanish /s/ in sociolinguistic interviews conducted in Cali and Barranquilla, Colombia. Two findings are highlighted: (1) frequency is only significant in the variety of Spanish that has low overall rates of /s/ reduction, Cali, and (2) form frequency is more influential than lemma frequency

An Analysis of Frequency as a Factor Contributing to the Diffusion of Variable Phenomena

Paper presented at the 13th Hispanic Linguistics Symposium, October 21-24, 2009, Universidad de Puerto Rico.This investigation examines the behavior of intervocalic dental fricative deletion in past-participle contexts versus all other instances, as well as palato-alveolar fricative devoicing to determine the effect of frequency. The evidence found reveals that lexical frequency and type frequency are relevant to explain rates of deletion in the case of intervocalic dental fricative. High frequency tokens show more deletion than less frequent ones. Past participles ending in -ado reflect the influence of high type frequency. Regarding devoicing of the palato-alveolar fricative, words that occur more frequently in contexts favoring the devoicing also devoice at a higher rate in disfavoring contexts as the phenomenon is spreading from favoring contexts to disfavoring ones. Furthermore, in the disfavoring context, low frequency words devoice at a higher rate than high frequency words. The evidence presented contributes to the growing body of studies regarding frequency effects on Spanish phonological processes

Variable Degrees of Constituency: Frequency Effects in the Alternation of pa vs. para in Spoken Discourse

Paper presented at the 14th Hispanic Linguistics Symposium, October 14-17, 2010, Indiana University.This study examines how repetition in discourse determines variable degrees of constituency between the preposition para 'to, for' and surrounding words, thus predicting greater reduction of para in cases where the degree of constituency is tightest. Our study contributes to the overall understanding of the role of usage in explaining reductive phonetic processes in contemporary Spanish. The findings of this corpus-based study of Caracas Spanish reveal that the frequency of the collocation is a key factor in predicting reduction of the form para. Further, frequency of use is a better explanation for the reduction of para than more traditional variables such as phonetic context. This result provides evidence to support the hypothesis that frequent combinations are accessed as autonomous units, due to their tighter degree of constituency, as in the case of I don't know in American English (Bybee and Scheibman 1999)

Going Retro: An Analysis of the Interplay between Socioeconomic Class and Age in Caracas Spanish

Paper presented at the 5th Workshop on Spanish Sociolinguistics, April 8-10, 2010, North Carolina State University.Socioeconomic class, whose definition in sociolinguistic studies often incorporates a range of variables such as education level, income, occupation, and residential area, amongst others, has been shown to be of profound importance in the patterning of sociolinguistic variation (Ash 2004, Labov 1972, Trudgill 1974). However, although education has often been argued to play a large role in the social stratification of sociolinguistic variables in the sociolinguistic literature, the influence of generational change in access to education has never been fully explored. The purpose of this study is to examine the influence of socioeconomic class and age in the patterning of linguistic behavior in the Spanish spoken in Caracas, Venezuela. To this end we examine syllable-final /ɾ/ deletion, intervocalic /ɾ/ deletion in para 'for', and intervocalic /d/ deletion. The findings of this investigation reveal that upper and middle class speakers are less likely to use vernacular variants of all three variables than the lower socioeconomic speakers in the speech community. This behavior of the upper and middle class in contrast with the working class in Caracas Spanish can in part be explained as a consequence of changes in access to education and occupation. Furthermore, as access to education increases in younger generations, a sharp rise in the use of the normative variants is reflected in the lowest socioeconomic class

Light and depth dependency of nitrogen fixation by the non‐photosynthetic, symbiotic cyanobacterium UCYN‐A

The symbiotic cyanobacterium UCYN-A is one of the most globally abundant marine dinitrogen (N2)-fixers, but cultures have not been available and its biology and ecology are poorly understood. We used cultivation-independent approaches to investigate how UCYN-A single-cell N2 fixation rates (NFRs) and nifH gene expression vary as a function of depth and photoperiod. Twelve-hour day/night incubations showed that UCYN-A only fixed N2 during the day. Experiments conducted using in situ arrays showed a light-dependence of NFRs by the UCYN-A symbiosis, with the highest rates in surface waters (5–45 m) and lower rates at depth (≥ 75 m). Analysis of NFRs versus in situ light intensity yielded a light saturation parameter (Ik) for UCYN-A of 44 μmol quanta m−2 s−1. This is low compared with other marine diazotrophs, suggesting an ecological advantage for the UCYN-A symbiosis under low-light conditions. In contrast to cell-specific NFRs, nifH gene-specific expression levels did not vary with depth, indicating that light regulates N2 fixation by UCYN-A through processes other than transcription, likely including host–symbiont interactions. These results offer new insights into the physiology of the UCYN-A symbiosis in the subtropical North Pacific Ocean and provide clues to the environmental drivers of its global distributions.En prens

N-linked Glycosylation Is Required for Optimal Function of Kaposi's Sarcoma Herpesvirus–encoded, but Not Cellular, Interleukin 6

Kaposi's sarcoma–associated herpesvirus interleukin-6 (vIL-6) is a structural and functional homologue of the human cytokine IL-6 (hIL-6). hIL-6 and vIL-6 exhibit similar biological functions and both act via the gp130 receptor subunit to activate the Janus tyrosine kinase (JAK)1 and signal transducer and activator of transcription (STAT)1/3 pathway. Here we show that vIL-6 is N-linked glycosylated at N78 and N89 and demonstrate that N-linked glycosylation at site N89 of vIL-6 markedly enhances binding to gp130, signaling through the JAK1-STAT1/3 pathway and functions in a cytokine-dependent cell proliferation bioassay. Although hIL-6 is also N-glycosylated at N73 and multiply O-glycosylated, neither N-linked nor O-linked glycosylation is necessary for IL-6 receptor α–dependent binding to gp130 or signaling through JAK1-STAT1/3. As distinct from vIL-6, unglycosylated hIL-6 is as potent as glycosylated hIL-6 in stimulating B cell proliferation. These findings highlight distinct functional roles of N-linked glycosylation in viral and cellular IL-6

A critical review of the N-15(2) tracer method to measure diazotrophic production in pelagic ecosystems

Dinitrogen (N-2) fixation is an important source of biologically reactive nitrogen (N) to the global ocean. The magnitude of this flux, however, remains uncertain, in part because N-2 fixation rates have been estimated following divergent protocols and because associated levels of uncertainty are seldom reported-confounding comparison and extrapolation of rate measurements. A growing number of reports of relatively low but potentially significant rates of N-2 fixation in regions such as oxygen minimum zones, the mesopelagic water column of the tropical and subtropical oceans, and polar waters further highlights the need for standardized methodological protocols for measurements of N-2 fixation rates and for calculations of detection limits and propagated error terms. To this end, we examine current protocols of the N-15(2) tracer method used for estimating diazotrophic rates, present results of experiments testing the validity of specific practices, and describe established metrics for reporting detection limits. We put forth a set of recommendations for best practices to estimate N-2 fixation rates using N-15(2) tracer, with the goal of fostering transparency in reporting sources of uncertainty in estimates, and to render N-2 fixation rate estimates intercomparable among studies

X-box binding protein 1 induces the expression of the lytic cycle transactivator of Kaposi's sarcoma-associated herpesvirus but not Epstein–Barr virus in co-infected primary effusion lymphoma

Cells of primary effusion lymphoma (PEL), a B-cell non-Hodgkin's lymphoma, are latently infected by Kaposi's sarcoma-associated herpesvirus (KSHV), with about 80 % of PEL also co-infected with Epstein–Barr virus (EBV). Both viruses can be reactivated into their lytic replication cycle in PEL by chemical inducers. However, simultaneous activation of both lytic cascades leads to mutual lytic cycle co-repression. The plasma cell-differentiation factor X-box binding protein 1 (XBP-1) transactivates the KSHV immediate–early promoter leading to the production of the replication and transcription activator protein (RTA), and reactivation of KSHV from latency. XBP-1 has been reported to act similarly on the EBV immediate–early promoter Zp, leading to the production of the lytic-cycle transactivator protein BZLF1. Here we show that activated B-cell terminal-differentiation transcription factor X-box binding protein 1 (XBP-1s) does not induce EBV BZLF1 and BRLF1 expression in PEL and BL cell lines, despite inducing lytic reactivation of KSHV in PEL. We show that XBP-1s transactivates the KSHV RTA promoter but does not transactivate the EBV BZLF1 promoter in non-B-cells by using a luciferase assay. Co-expression of activated protein kinase D, which can phosphorylate and inactivate class II histone deacetylases (HDACs), does not rescue XBP-1 activity on Zp nor does it induce BZLF1 and BRLF1 expression in PEL. Finally, chemical inducers of KSHV and EBV lytic replication in PEL, including HDAC inhibitors, do not lead to XBP-1 activation. We conclude that XBP-1 specifically reactivates the KSHV lytic cycle in dually infected PELs