Thermal-Expansion and Fracture Toughness Properties ofParts made from Liquid Crystal Stereolithography Resins

Liquid crystal (LC) resins are a new kind ofstereolithography material that can produce parts with structured or ordered morphologies instead ofthe amorphous morphologies that result from standard resins. The LC molecules can be aligned before cure resulting in an anisotropic crosslinked network when the laser induced polymerization "locks-in" the alignment. Previous papers have explored liquid crystal orientation dynamics [1], the effects of orientation on viscoelastic and mechanical properties [2,3], and the processing ofLC resins by stereolithography [4]. This paper considers the effects ofmorphology on fracture toughness and thermal-expansion properties. Both toughness and thermal-stability continue to be important issues for stereolithography parts. The use ofLC resins may provide a way to significantly improve performance in both ofthese areas, and in addition result in parts with high upper use . temperatures.Mechanical Engineerin

Utilising the ubiquity of the cell phone to record physiological activities

Lifelogging is a term used to describe recording different aspects of your daily life, in digital form, for your own exclusive personal use. It is a form of reverse surveillance, sometimes termed sousveillance, referring to us - the subjects - doing the watching, of ourselves. In today's healthcare world where we react to conditions that have already developed, lifelogging technologies may offer a glimpse into a future world of proactive healthcare where symptoms of conditions are detected at much earlier stages. At the end of last year it was estimated that there were 4 billion cell phones in the world, in comparison to just over 1 billon PCs. In this presentation I will discuss a framework, which leverages the ubiquity of the cell phone, to aggregate multiple wearable biological sensors. This physiological lifelogged data can then be easily queried via an interface which utilises contextual memory retrieval cues to assist people remember what type of activity they were doing at a particular time. This may be helpful for the diagnosis of potential medical conditions e.g. to explain that my heart rate was very high because I was at the gym, or that I had a disturbed night's sleep because I was in an unfamiliar hotel room

Nonlinear Differential Equation Reconstruction and Taken’s Embedding Theorem

The considerable usefulness of differential equations in modeling physical system dynamics is limited by the ability to generate equations which accurately reproduce observed behavior. Especially in the case of nonlinear systems, finding such a set of differential equations can be a nontrivial problem. However, there are numerical methods for generating differential equations to model empirical data. This paper briefly outlines the trajectory method of Perona et al. for fitting a system of differential equations to time series data. The basis of the system of equations needed to optimize the model are given. Creation of an algorithm to implement the method is discussed. The ability of the algorithm to reconstruct nonlinear systems with chaotic behavior is demonstrated. This method has great flexibility, allowing for direct application to the analysis of many systems without requiring prior knowledge of the underlying mechanisms

Color-Blind Racial Attitudes in Practicing Dental Hygienists

Purpose: Individuals who subscribe to a color-blind racial ideology may not be aware of differences or differential treatment based on race which may be related to racial inequality in the delivery of oral health care. The purpose of this study was to determine color-blind racial attitudes in a convenience sample of clinical dental hygienists. Methods: A convenience sample of practicing dental hygienists recruited through social media via snowball sampling was invited to participate in this cross-sectional survey study. The Color-Blind Racial Attitudes Scale (CoBRAS), a valid and reliable measuring instrument, was used to determine unawareness of racial attitudes and stereotyping. Three subscales (Racial Privilege, Institutional Discrimination, and Blatant Racial Issues) were measured by the survey. Descriptive statistics and separate one-way between-subjects ANOVA were used to analyze the data. Results: Two-hundred and thirty-three (n = 233) dental hygienists in clinical practice completed the survey. ANOVA revealed statistically significant differences in overall CoBRAS scores when comparing age groups and ethnicities. Participants aged 18-29 had significantly lower overall CoBRAS scores compared to participants aged 60 and over (x = 49.41, x = 59.17, respectively; p = .019). African American participants scored significantly lower on overall CoBRAS scores compared only to those in the Other ethnicity category (x = 42.27, x = 62.08, respectively; p = .029). Conclusion: Participants possessed moderate levels of color-blindness, suggesting unawareness of racism and a need to understand the implications of racism as a means of promoting equity and improve oral health care delivery. Findings emphasize a need for more research examining color-blind ideology and how it affects oral health care delivery to diverse patient populations

Time-Based Clustering and Its Relationship with Mutual Information Theory

This paper re-introduces the concepts of TimeBased Clustering (TBC). Also, the ideas of oversampling and embedding time are introduced in connection with mutual information theory. These concepts are then extended through the use of the Time-Based Clustering (TBC) problem. Mutual information curves for the Rössler system are shown to match a slice through the rich cost function space spanned by the Time-Based Clustering (TBC) solution. In closing, some possible repercussions of this find are discussed

Color-Blind Racial Attitudes in Dental Hygiene Students: A Pilot Study

Purpose: Color-blind racial attitudes and biases have been linked to racial prejudice which may potentially affect dental hygiene care to diverse patients. The purpose of this pilot study was to determine the color-blind racial attitudes of dental hygiene students. Methods: A 20-item, Color-Blind Racial Attitudes Scale (CoBRAS) electronic survey was sent to a convenience sample of 41 first-year and 30 second-year dental hygiene students (n=71) in a dental hygiene program in Virginia. The CoBRAS instrument measures contemporary racial attitudes and stereotyping in three subcategories: Unawareness of Racial Privilege, Institutional Discrimination, and Blatant Racial Issues. CoBRAS scores range from 20-120, with higher scores indicating elevated levels of denial of racism. Descriptive statistics were used to analyze the data. Results: Of the 71 students invited to participate, 70 completed the survey (n=70) for a 98.6% response rate. The majority of respondents were White females (70%, 98% respectively), aged 18-29 (90%). Results indicated an overall average CoBRAS score of 64.89. No statistically significant findings were identified between the two groups in regards to overall scores (p\u3e0.05). Conclusion: A majority of the participants in this pilot study possessed moderate levels of color-blind racial attitudes, suggesting rejection of the concept of racism. Color-blind racial attitudes and biases have been linked to a lack of awareness of White privilege. Further education in this area may foster improved interactions with diverse patient populations

A Study of Visible Tattoos in Entry -Level Dental Hygiene Education Programs

Purpose: The purpose of this study was to survey entry-level dental hygiene program directors in the United States (US) to assess their perceptions of dental hygienists with visible tattoos as well as to determine current policies related to dress codes in US dental hygiene programs. Methods: Data was collected with an online survey emailed to 340 dental hygiene program directors from March to April 2016, yielding a 43% (n = 141) response rate. Participants indicated their opinions of visible tattoos on the basis of professionalism and school policy requirements. Results: Eighty percent of respondents reported their program had dress code policies on visible tattoos, with the majority (97%) requiring visible tattoos to be covered. Results revealed that both students (M = 5.57, p Conclusion: Results showed that visible tattoos were not perceived favorably in general, and that the dental hygiene program director\u27s personal perceptions may have influenced existing school dress code polices. These findings provide evidenced based information for hygienists, students, faculty, administrators and hiring managers as they formulate institution policies relating to body art

Attitudes of Virginia Dental Hygienists Towards Dental Therapists

Purpose: The state of Virginia faces a reported dental health professional shortage affecting approximately half of its residents.The purpose of this study was to assess the opinions and attitudes of dental hygienists in Virginia toward a mid-level dental provider model, dental therapists (DTs), and to determine whether current education level and years of practice affected opinions regarding the education requirements for DTs. Methods: A 22-item questionnaire was distributed online to a convenience sample of Virginia dental hygienists (n=910). Items assessed attitudes of participants toward the DT using a seven-point Likert-type scale ranging from 1 (strongly disagree) to 7 (strongly agree). Participants were asked to provide demographic information and to respond to open-ended questions regarding potential advantages and/or disadvantages to DTs. Independent samples t-tests and chi-square analyses were used to analyze the data. Results: A response rate of 22% was obtained (n=200). Most respondents agreed a DT was needed in Virginia (M=5.78, p\u3c0.001) and supported the concept that dental therapy could be a solution to the problem of access to care issues in Virginia (M=5.97, p\u3c0.001). While most respondents agreed it was important for Virginia to adopt legislation for a dental therapy model (M=5.89, p\u3c0.001), most disagreed that DTs’ practice should be restricted to acknowledged underserved areas in the state (M=3.19, p\u3c0.001). No significant association was found between years of practice and opinions toward education requirements for DTs; however, a significant association was found between current education level and opinions toward education requirements for DTs (Fisher’s Exact Test=34.17, df=9, p=.000, Cramer’s V=.28). Conclusion: Results revealed Virginia dental hygienists had overwhelmingly positive attitudes toward DTs. Research with a larger sample could provide more insight into opinions of the Virginia dental hygienist population regarding this mid-level oral health care provider

Effects of Instrument Handle Design on Dental Hygienists\u27 Forearm Muscle Activity During Scaling

Purpose: The purpose of this study was to determine the effects of 4 different commercially available instrument handle designs (A. 16 grams and 12.7 mm diameter, B. 23 grams and 11.1 mm diameter, C. 21 grams and 7.9 mm diameter and D. 18 grams and 6.35 mm diameter) on the muscle activity of four forearm muscles during a simulated scaling experience. Methods: A convenience sample of 27 (n=27) dental hygienists used a Columbia 13/14 curet with four different instrument handles to scale artificial calculus from typodont teeth. Each participant\u27s muscle activity was measured using surface electromyography (sEMG). Results: Similar muscle activity was generated when scaling with instruments at 16, 18, and 21 grams with varying diameter handles. Instrument B generated significantly more muscle activity when compared to each of the other instrument handle designs (p=0.001, p=0.002, p=0.039). The lower left quadrant displayed significantly less muscle activity during scaling than the upper and lower right quadrants (p=0.026, p=0.000), although no significant interaction effect was found with instruments within quadrants. Most participants (62.96%) preferred instrument A, which was rated more comfortable based on weight when compared to the other instruments tested. Conclusions: Instrument handle design has an effect on forearm muscle activity when scaling in a simulated environment. The heaviest instrument with a relatively large diameter (B 11.1 mm and 23 g) generated significantly more overall mean muscle activity compared to the other three instruments. Similar amounts of muscle activity were produced by instruments weighing between 16 and 21 g. Participants\u27 instrument preferences were more affected by handle diameter than weight. Results support the need for further research to determine the impact of these findings on muscle load related to risk of musculoskeletal disorders in a real-world setting