Fluoride and oral health

The discovery during the first half of the 20th century of the link between natural fluoride, adjusted fluoride levels in drinking water and reduced dental caries prevalence proved to be a stimulus for worldwide on-going research into the role of fluoride in improving oral health. Epidemiological studies of fluoridation programmes have confirmed their safety and their effectiveness in controlling dental caries. Major advances in our knowledge of how fluoride impacts the caries process have led to the development, assessment of effectiveness and promotion of other fluoride vehicles including salt, milk, tablets, toothpaste, gels and varnishes. In 1993, the World Health Organization convened an Expert Committee to provide authoritative information on the role of fluorides in the promotion of oral health throughout the world (WHO TRS 846, 1994). This present publication is a revision of the original 1994 document, again using the expertise of researchers from the extensive fields of knowledge required to successfully implement complex interventions such as the use of fluorides to improve dental and oral health. Financial support for research into the development of these new fluoride strategies has come from many sources including government health departments as well as international and national grant agencies. In addition, the unique role which industry has played in the development, formulation, assessment of effectiveness and promotion of the various fluoride vehicles and strategies is noteworthy. This updated version of ‘Fluoride and Oral Health’ has adopted an evidence-based approach to its commentary on the different fluoride vehicles and strategies and also to its recommendations. In this regard, full account is taken of the many recent systematic reviews published in peer reviewed literature

Extended morphometric analysis of neuronal cells with Minkowski valuations

Minkowski valuations provide a systematic framework for quantifying different aspects of morphology. In this paper we apply vector- and tensor-valued Minkowski valuations to neuronal cells from the cat's retina in order to describe their morphological structure in a comprehensive way. We introduce the framework of Minkowski valuations, discuss their implementation for neuronal cells and show how they can discriminate between cells of different types.Comment: 14 pages, 18 postscript figure

The Acid Test of Fluoride: How pH Modulates Toxicity

Background: It is not known why the ameloblasts responsible for dental enamel formation are uniquely sensitive to fluoride ($F^−$). Herein, we present a novel theory with supporting data to show that the low pH environment of maturating stage ameloblasts enhances their sensitivity to a given dose of $F^−$. Enamel formation is initiated in a neutral pH environment (secretory stage); however, the pH can fall to below 6.0 as most of the mineral precipitates (maturation stage). Low pH can facilitate entry of $F^−$ into cells. Here, we asked if $F^−$ was more toxic at low pH, as measured by increased cell stress and decreased cell function. Methodology/Principal Findings: Treatment of ameloblast-derived LS8 cells with $F^−$ at low pH reduced the threshold dose of $F^−$ required to phosphorylate stress-related proteins, PERK, eIF2α, JNK and c-jun. To assess protein secretion, LS8 cells were stably transduced with a secreted reporter, Gaussia luciferase, and secretion was quantified as a function of $F^−$ dose and pH. Luciferase secretion significantly decreased within 2 hr of $F^−$ treatment at low pH versus neutral pH, indicating increased functional toxicity. Rats given 100 ppm $F^−$ in their drinking water exhibited increased stress-mediated phosphorylation of eIF2α in maturation stage ameloblasts (pH<6.0) as compared to secretory stage ameloblasts (pH∼7.2). Intriguingly, $F^−$-treated rats demonstrated a striking decrease in transcripts expressed during the maturation stage of enamel development (Klk4 and Amtn). In contrast, the expression of secretory stage genes, AmelX, Ambn, Enam and Mmp20, was unaffected. Conclusions: The low pH environment of maturation stage ameloblasts facilitates the uptake of $F^−$, causing increased cell stress that compromises ameloblast function, resulting in dental fluorosis

IRAS F02044+0957: radio source in interacting system of galaxies

The steep spectrum of IRAS F02044+0957 was obtained with the RATAN-600 radio telescope at four frequencies. Optical spectroscopy of the system components, was carried out with the 2.1m telescope of the Guillermo Haro Observatory. Observational data allow us to conclude that this object is a pair of interacting galaxies, a LINER and a HII galaxy, at $z=0.093$.Comment: 2 pages, 2 EPS-figures, uses newpasp.sty. To appear in Proc. IAU Colloq. 184, AGN Surveys, ed. R. F. Green, E. Ye. Khachikian, & D. B. Sanders (San Francisco: ASP

Lunar Outgassing, Transient Phenomena and The Return to The Moon, I: Existing Data

Herein the transient lunar phenomena (TLP) report database is subjected to a discriminating statistical filter robust against sites of spurious reports, and produces a restricted sample that may be largely reliable. This subset is highly correlated geographically with the catalog of outgassing events seen by the Apollo 15, 16 and Lunar Prospector alpha-particle spectrometers for episodic Rn-222 gas release. Both this robust TLP sample and even the larger, unfiltered sample are highly correlated with the boundary between mare and highlands, as are both deep and shallow moonquakes, as well as Po-210, a long-lived product of Rn-222 decay and a further tracer of outgassing. This offers another significant correlation relating TLPs and outgassing, and may tie some of this activity to sagging mare basalt plains (perhaps mascons). Additionally, low-level but likely significant TLP activity is connected to recent, major impact craters (while moonquakes are not), which may indicate the effects of cracks caused by the impacts, or perhaps avalanches, allowing release of gas. The majority of TLP (and Rn-222) activity, however, is confined to one site that produced much of the basalt in the Procellarum Terrane, and it seems plausible that this TLP activity may be tied to residual outgassing from the formerly largest volcanic ffusion sites from the deep lunar interior. With the coming in the next few years of robotic spacecraft followed by human exploration, the study of TLPs and outgassing is both promising and imperiled. We will have an unprecedented pportunity to study lunar outgassing, but will also deal with a greater burden of anthropogenic lunar gas than ever produced. There is a pressing need to study lunar atmosphere and its sources while still pristine. [Abstract abridged.]Comment: 35 pages, 3 figures, submitted to Icarus. Other papers in series found at http://www.astro.columbia.edu/~arlin/TLP

Crowding Promotes the Switch from Hairpin to Pseudoknot Conformation in Human Telomerase RNA

Formation of a pseudoknot in the conserved RNA core domain in the ribonucleoprotein human telomerase is required for function. In vitro experiments show that the pseudoknot (PK) is in equilibrium with an extended hairpin (HP) structure. We use molecular simulations of a coarse-grained model, which reproduces most of the salient features of the experimental melting profiles of PK and HP, to show that crowding enhances the stability of PK relative to HP in the wild type and in a mutant associated with dyskeratosis congenita. In monodisperse suspensions, small crowding particles increase the stability of compact structures to a greater extent than larger crowders. If the sizes of crowders in a binary mixture are smaller than the unfolded RNA, the increase in melting temperature due to the two components is additive. In a ternary mixture of crowders that are larger than the unfolded RNA, which mimics the composition of ribosome, large enzyme complexes and proteins in E. coli, the marginal increase in stability is entirely determined by the smallest component. We predict that crowding can restore partially telomerase activity in mutants, which dramatically decrease the PK stability.Comment: File "JACS_MAIN_archive_PDF_from_DOC.pdf" (PDF created from DOC) contains the main text of the paper File JACS_SI_archive.tex + 7 figures are the supplementary inf

“I'm a Referee, Not a Female Referee”: The Experiences of Women Involved in Football as Coaches and Referees

The development of the Women's Super League (WSL) in English football, increased media coverage of the game, and an expansion of grassroots opportunities indicate a bright future for women and girls who want to play. Yet this vision must be tempered against compelling evidence of deep rooted and enduring gender inequalities within the game. This is the case for both players, and women who undertake non-playing roles, which is reflected in the relatively low numbers of women coaches and referees. Whilst The Football Association (The FA) has signalled addressing these inequalities as a key priority, critics argue that such efforts amount to superficial and limited efforts to support meaningful change. This paper departs from a concern with playing the game and responds to calls for more research to explore the experiences of women involved in football in non-playing roles. More specifically, it focuses on women coaches and referees, and addresses the following question: how do women in positions of power in football negotiate their place in what remains a distinctly male-dominated profession? In addressing this question, we take a theoretical position located at the nexus between radical and post-structural feminism, acknowledging the significance of structural power relations and individual agency in shaping daily lived social realities. Data were generated from interviews with 14 women coaches and 10 women referees. These interviews explored the structure and culture of the game and its impact on women's experiences of men's and women's competitive and grassroots football. Through a rigorous process of thematic analysis, three themes were identified: gendered entry into football careers; reinforcement of women's difference on the football field; and coping strategies for remaining in the game. Centralising the women's voices in this research highlights the insidious and persistent nature of gendered microaggressions, the sexism of football culture, and the ways in which these women negotiate this masculine terrain in their pursuit of being coaches and referees. “Andy Gray and Richard Keys hauled off air for sexist comments” (The Guardian, 24 January, 2011) “Crystal Palace Women goalkeeper accuses clubs of ignoring FA protocols after she was subjected to sexist abuse” (The Telegraph, 16 January, 2020) “Football manager demands ban on women referees” (The Guardian, 12 November, 2006) “Richard Scudamore sexism scandal intensifies as conspirator in sexist emails investigated by own law firm” (The Telegraph, 16 May, 2014) “Soccer chief's plan to boost women's game? Hotpants” (The Guardian, 16 January, 2004) “Women in Football survey a damning indictment of sexism in the workplace” (HRreview, 11 March, 2014) “Clattenburg criticised for claim female referees must pick career or children” (The Telegraph, 1 October, 2021

Pregnant women’s awareness, knowledge and beliefs about pelvic floor muscles: a cross-sectional survey

Introduction and hypothesis: Pregnant women benefit from completing pelvic floor muscle exercises (PFMEs). The aims of the study were to evaluate pregnant women’s levels of awareness, knowledge, and beliefs about the pelvic floor muscles (PFMs) and PFMEs. Methods: A cross-sectional survey was conducted. Respondents were pregnant women over the age of 18 years who attended antenatal clinics in Western Australia (WA). Questionnaire items measured awareness and knowledge about PFMs, confidence and beliefs about engaging in PFMEs, and attendance at antenatal education (ANE) classes. Chi-squared tests examined potential associations between questionnaire items and respondent characteristics. Results: Mean gestation of respondents (n = 633 out of 850; 74% response rate) was 28.7 (+7.8) weeks and 50% were giving birth for the first time. Although 76% of respondents knew that PFMs can prevent urinary incontinence, only 27% knew that they prevented faecal incontinence and 41% thought it was normal to leak urine when pregnant. Only n = 72 (11%) were practicing PFMEs. Respondents who had attended ANE (28%) were significantly more knowledgeable about pelvic floor function (p &lt; .001) and significantly less likely to believe that leaking urine during pregnancy was normal (p = 0.02), compared with those who had not attended ANE. Respondents who did not speak English at home (18%) were significantly less knowledgeable about PFMs and PFMEs, and significantly less likely to have attended, or planned to attend, ANE classes. Conclusion: Pregnant women require more health education regarding PFMs. Education should be provided using diverse modes, especially for women from migrant backgrounds and women who do not plan to attend formal ANE classes

Tradeoffs in jet inlet design: a historical perspective

The design of the inlet(s) is one of the most demanding tasks of the development process of any gas turbine-powered aircraft. This is mainly due to the multi-objective and multidisciplinary nature of the exercise. The solution is generally a compromise between a number of conflicting goals and these conflicts are the subject of the present paper. We look into how these design tradeoffs have been reflected in the actual inlet designs over the years and how the emphasis has shifted from one driver to another. We also review some of the relevant developments of the jet age in aerodynamics and design and manufacturing technology and we examine how they have influenced and informed inlet design decision

Capturing the essence of folding and functions of biomolecules using Coarse-Grained Models

The distances over which biological molecules and their complexes can function range from a few nanometres, in the case of folded structures, to millimetres, for example during chromosome organization. Describing phenomena that cover such diverse length, and also time scales, requires models that capture the underlying physics for the particular length scale of interest. Theoretical ideas, in particular, concepts from polymer physics, have guided the development of coarse-grained models to study folding of DNA, RNA, and proteins. More recently, such models and their variants have been applied to the functions of biological nanomachines. Simulations using coarse-grained models are now poised to address a wide range of problems in biology.Comment: 37 pages, 8 figure