935 research outputs found
The solution of equations,
No full textReissue of Chapter 1 of Higher mathematics, ed. by M. Merriman and R. S. Woodward, 1896
Impact of skeletal divergence on oral health-related quality of life and self-reported jaw function
No full textObjective: To investigate the differences in oral health-related quality of life (OHRQoL) and self-reported jaw function between patients with hyperdivergent and normodivergent facial types. Methods: Eighty patients with a distinctively hyperdivergent facial type (mandibular plane angle greater than 2 standard deviations, or 42 degrees) and 80 controls were individually matched according to age, sex, ethnicity, and treatment stage. Data were collected using self-report questionnaires such as the Oral Health Impact Profile (OHIP-14) and Jaw Functional Limitation Scale (JFLS-8). Results: The mean age of the patients was 17.2 +/- 4.6 years (range, 12-49 years), with most (65.0%) being female and of New Zealand European origin (91.3%). Individuals with hyperdivergent facial types had higher overall and social domain scores on the OHIP-14 (p 0.05). Conclusions: Jaw function appears to be similar in individuals with hyperdivergent and normodivergent facial morphologies. However, those with hyperdivergent facial types are more likely to self-report poorer OHRQoL than are those with normal faces, especially in relation to social aspects
Factors associated with orthodontic pain
No full textBackground: Pain experienced at teeth during orthodontic treatment varies largely over time, with the reasons for its interindividual variability being largely unknown: age, sex, clinical activations, psychosocial factors and genetic polymorphisms of candidate genes are putative factors that may account to explain this variability. We aimed to investigate the effect of clinical, demographic, psychological and genetic factors on pain levels experienced during fixed orthodontic treatment. Methods: A convenience sample of 183 patients undergoing full-fixed orthodontic treatment were recruited. Participant's pain levels were assessed seven times over a three-day period via a smartphone app. Clinical, demographic and psychological data were collected via questionnaires. This included the Pain Catastrophising Scale (Child version), the Corah Dental Anxiety Scale and the State and Trait Anxiety Inventory. Participants provided a DNA sample either in the form of blood or saliva, which were used for genotyping COMT gene rs6269, rs4680, rs4646310, NR3C1 gene rs2963155 and the HTR2A gene rs9316233. Results: Bond ups had the greatest influence on perceived levels of pain experienced on teeth during orthodontic treatment, accounting for over 20% of total variance in pain response. High-pain responders had higher scores on pain catastrophising (magnification subscale). Self-reported pain during fixed orthodontic treatment was not influenced by sex, age, time into treatment, anxiety, nor by polymorphisms of COMT, HTR2A or NR3C1 genes. Conclusions: Pain on teeth resulting from orthodontic fixed appliances is stronger during bonds-up and in patients with high catastrophising scores. Demographics, type of clinical activations and the genetic polymorphisms investigated in this research had little or no impact on perceived pain levels
Self-reported oral behaviour habits in hyperdivergent and normodivergent facial types
No full textThe relationship between facial morphology and jaw function remains controversial. The purpose of this study was to investigate differences in self-reported oral behaviour habits between individuals with normodivergent and hyperdivergent facial types. Some 80 cases and controls were individually matched on age, sex ethnicity and treatment stage. The participants were recruited from an orthodontic clinic, and included both adolescents and adults. Habitual oral activity was assessed using the Oral Behaviour Checklist (OBC) based on their experiences in the past 4 weeks. Univariate and bivariate analyses were performed. The sample had a mean age of 17·2 years (SD = 4·6; range = 12–49 years), and was predominantly female (65·0%) and of New Zealand European origin (91·3%). The prevalence of reporting one or more frequently performed habitual muscular behaviour in either study group was over 85% (P > 0·05). There was no difference in total OBC score between the hyperdivergent (25·6; SD: 9·0) and normodivergent group (25·3; SD: 9·9). Moreover, there was no difference in the prevalence of either nocturnal or daytime oral behaviours between the two groups. While this study did not include any objective measures of functional or habitual activity, we found no differences in self-reported oral behaviour habits between normodivergent and hyperdivergent individuals. The findings do not support an association between vertical facial form and habitual muscular activity
Building evaluation capacity in small/medium-sized conservation projects
No full textSmall/medium-sized projects make up a key component of the work of many conservation organisations. Given the challenges facing global biodiversity it is essential that we are able to evaluate and learn from the outcomes and impacts of such projects . Furthermore, many of those working in conservation receive their first experience of practical conservation work through managing and implementing projects of this scale, therefore instilling good evaluation practises at this level can also act as a valuable capacity-building experience which further enhances the potential impact of such projects.
PRISM is a toolkit developed by a collaboration of organisations in the Cambridge Conservation Initiative, with additional input from academics, practitioners and donors from across the conservation sector. The toolkit aims to support small/medium-sized conservation projects to evaluate the outcomes and impacts of their work, specifically to help projects:
• Understand the theory behind evaluation relevant to small/medium-sized conservation projects
• Plan project evaluation in a way that maximises useful information while remaining feasible to carry out
• Use practical, easy to use methods to collect and analyse evaluation data that can be adapted for specific conservation scenarios
• Interpret, communicate and apply evaluation results to improve current practise
The toolkit addresses the need to build evaluation capacity in such projects, reconciling the challenges they face with the need to go beyond only measuring what has been done and to look at what difference the project has made, what lessons have been learnt and what should be done next.
Ferraro PJ, Pattanayak SK (2006) Money for Nothing? A Call for Empirical Evaluation of Biodiversity Conservation Investments. PLoS Biol 4(44)
Dickson, I. M., Butchart, S. H. M., Dauncey, V., Hughes, J., Jefferson, R., Merriman, J. C., Munroe, R., Pearce-Higgins, J. P., Stephenson, P. J., Sutherland, W. J., Thomas, D. H. L., & Trevelyan, R., (2017) PRISM – Toolkit for evaluating the outcomes and impacts of small/medium-sized conservation projects. Cambridge Conservation Initiative. Version 1. Available from www.conservationevaluation.orgpeerReviewedunknown accessibilityei tietoa saavutettavuudest
Age constraints and geochemistry of the Ordovician Tyrone Igneous Complex, Northern Ireland : implications for the Grampian orogeny
No full textThe Tyrone Igneous Complex is one of the largest areas of ophiolitic and arc-related rocks exposed along the northern margin of Iapetus within the British and Irish Caledonides. New U–Pb zircon data and regional geochemistry suggest that the Tyrone Plutonic Group represents the uppermost portions of a c. 480 Ma suprasubduction-zone ophiolite accreted onto an outboard segment of Laurentia prior to 470.3 ± 1.9 Ma. The overlying Tyrone Volcanic Group formed as an island arc that collided with the Laurentian margin during the Grampian phase of the Caledonidan orogeny. Early magmatism is characterized by transitional to calc-alkaline, light REE (LREE)-enriched island-arc signatures, with an increasing component of continentally derived material up sequence. Tholeiitic rhyolites with flat to U-shaped REE profiles and LREE-depleted basalts, located stratigraphically below a c. 473 Ma rhyolite of the upper Tyrone Volcanic Group, suggest initiation of intra-arc rifting at c. 475 Ma. Metamorphic cooling ages from the Tyrone Central Inlier imply arc–continent collision before 468 ± 1.4 Ma, with the emplacement of the Tyrone Volcanic Group onto the margin. A suite of 470.3 ± 1.9 Ma to 464.3 ± 1.5 Ma calc-alkaline intrusions are associated with the continued closure of Iapetus.
Supplementary material: Geochemical data and petrography are available at http://www.geolsoc.org.uk/SUP18467
Maternal Smoking during Pregnancy Is Associated with Offspring Hypodontia
No full text Little is known about environmental risk factors for hypodontia. The objective of this study was to investigate the association between hypodontia and common environmental risk factors, such as maternal smoking and alcohol and caffeine consumption during pregnancy. Eighty-nine hypodontia cases with 1 or more missing permanent lateral incisors and/or 1 or more missing premolars were enrolled in this clinic-based case-control study. Some 253 controls with no missing teeth were frequency matched to cases by age and sex. Hypodontia was diagnosed using panoramic radiographs. Sociodemographic data were collected from both the participants and their mothers, with maternal self-reported active and passive smoking, as well as alcohol and caffeine consumption during pregnancy, assessed by a questionnaire. Odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated with logistic regression to assess the strength of association between risk factors and hypodontia. OR estimates were then adjusted for possible confounders, such as maternal age at delivery, sex and gestational age of the child, and household socioeconomic background. Significant associations were found between hypodontia and maternal cigarette use during pregnancy, as well as the number of cigarettes smoked per day. The consumption of 10 or more cigarettes per day during pregnancy was associated with greater odds of having a child with hypodontia (adjusted OR, 4.18; 95% CI, 1.48–11.80; P = 0.007). Observed associations between hypodontia, second-hand smoke, and alcohol and caffeine consumption were not statistically significant. Maternal smoking during pregnancy is associated with hypodontia. Larger samples and prospective observational study designs, however, are needed to investigate this association further. </jats:p
DNA double strand breaks but not interstrand crosslinks prevent progress through meiosis in fully grown mouse oocytes
No full textThere is some interest in how mammalian oocytes respond to different types of DNA damage because of the increasing expectation of fertility preservation in women undergoing chemotherapy. Double strand breaks (DSBs) induced by ionizing radiation and agents such as neocarzinostatin (NCS), and interstrand crosslinks (ICLs) induced by alkylating agents such as mitomycin C (MMC), are toxic DNA lesions that need to be repaired for cell survival. Here we examined the effects of NCS and MMC treatment on oocytes collected from antral follicles in mice, because potentially such oocytes are readily collected from ovaries and do not need to be in vitro grown to achieve meiotic competency. We found that oocytes were sensitive to NCS, such that this ionizing radiation mimetic blocked meiosis I and caused fragmented DNA. In contrast, MMC had no impact on the completion of either meiosis I or II, even at extremely high doses. However, oocytes treated with MMC did show ?-H2AX foci and following their in vitro maturation and parthenogenetic activation the development of the subsequent embryos was severely compromised. Addition of MMC to 1-cell embryos caused a similarly poor level of development, demonstrating oocytes have eventual sensitivity to this ICL-inducing agent but this does not occur during their meiotic division. In oocytes, the association of Fanconi Anemia protein, FANCD2, with sites of ICL lesions was not apparent until entry into the embryonic cell cycle. In conclusion, meiotic maturation of oocytes is sensitive to DSBs but not ICLs. The ability of oocytes to tolerate severe ICL damage and yet complete meiosis, means that this type of DNA lesion goes unrepaired in oocytes but impacts on subsequent embryo quality
are associated with non‐syndromic hypodontia
No full textObjective: The aim of this case-control study was to investigate the association between non-syndromic hypodontia and nineteen common variants of candidate genes ectodysplasin A (EDA), paired box 9 (PAX9), msh homeobox 1 (MSX1) and axis inhibition protein 2 (AXIN2). Settings and Sample Population: Sixty-one hypodontia cases were frequency-matched to 253 controls with no missing teeth (excluding the third molars). Material and Methods: Self-report data and DNA samples were collected from each participant. Results: The sample had a mean age of 16.6 years (SD = 7.3), with most participants being female (59.6%), and of New Zealand European origin (75.4%). Using multiple logistic regression analysis, it was found that the T-allele of rs12853659 (EDA) and the G-allele of rs2428151 (EDA) were both associated with a higher risk of hypodontia (odds ratio, OR = 2.79, 95% CI = 1.11-7.01; and OR = 2.87, 95% CI = 1.04-7.94, respectively). The G-allele of rs2520378 (EDA) showed a protective effect with an OR of 0.61 (95% CI = 0.38-0.99). The EDA SNP findings were consistent with previous reports included in a meta-analysis. No associations were found with the PAX9, AXIN2 and MSX1 genes, after adjusting for sex and ethnicity. Conclusions: Common variants of the EDA genes are associated with specific phenotypes of non-syndromic hypodontia, thus confirming their role in the regulatory pathways of normal tooth development. However, larger samples are needed to investigate the association further
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