Search for: All records

Despite the cariogenic role of Candida suggested from recent studies, oral Candida acquisition in children at high risk for early childhood caries (ECC) and its association with cariogenic bacteria Streptococcus mutans remain unclear. Although ECC disproportionately afflicts socioeconomically disadvantaged and racial-minority children, microbiological studies focusing on the underserved group are scarce. Our prospective cohort study examined the oral colonization of Candida and S. mutans among 101 infants exclusively from a low-income and racial-minority background in the first year of life. The Cox hazard proportional model was fitted to assess factors associated with the time to event of the emergence of oral Candida and S. mutans. Oral Candida colonization started as early as 1 wk among 13% of infants, increased to 40% by 2 mo, escalated to 48% by 6 mo, and remained the same level until 12 mo. S. mutans in saliva was detected among 20% infants by 12 mo. The emergence of S. mutans by year 1 was 3.5 times higher (hazard ratio [HR], 3.5; confidence interval [CI], 1.1–11.3) in infants who had early colonization of oral Candida compared to those who were free of oral Candida ( P = 0.04) and 3 times higher (HR, 3.0; CI, 1.3–6.9) among infants whose mother had more than 3 decayed teeth ( P = 0.01), even after adjusting demographics, feeding, mother’s education, and employment status. Infants’ salivary S. mutans abundance was positively correlated with infants’ Candida albicans ( P < 0.01) and Candida krusei levels ( P < 0.05). Infants’ oral colonization of C. albicans was positively associated with mother’s oral C. albicans carriage and education ( P < 0.01) but negatively associated with mother’s employment status ( P = 0.01). Future studies are warranted to examine whether oral Candida modulates the oral bacterial community as a whole to become cariogenic during the onset and progression of ECC, which could lead to developing novel ECC predictive and preventive strategies from a fungal perspective. 

We consider the isoperimetric problem for the sum of two Gaussian densities in the line and the plane. We prove that the double Gaussian isoperimetric regions in the line are rays and that if the double Gaussian isoperimetric regions in the plane are half-spaces, then they must be bounded by vertical lines. 

Like many natural sciences, a critical component of archaeology is field work. Despite its importance, field opportunities are available to few students for financial and logistical reasons. With little exposure to archaeological research, fewer students are entering archaeology, particularly minority students (Smith 2004; Wilson 2015). To counter these trends, we have leveraged the ongoing revolution in consumer electronics for the current, digitally-empowered generation by creating a game-based, virtual archaeology curriculum to 1) teach foundational principles of a discipline that is challenging to present in a traditional classroom by using sensory and cognitive immersion; and, 2) allow wider access to a field science that has previously been limited to only select students. Virtual reality (VR) is computer technology that creates a simulated three-dimensional world for a user to experience in a bodily way, thereby transforming data analysis into a sensory and cognitive experience. Using a widely-available, room-scale, VR platform, we have created a virtual archaeological excavation experience that conveys two overarching classroom objectives: 1) teach the physical methods of archaeological excavation by providing the setting and tools for a student to actively engage in field work; and, 2) teach archaeological concepts using a scientific approach to problem solving by couching them within a role-playing game. The current prototype was developed with the HTC Vive VR platform, which includes a headset, hand controllers, and two base stations to track the position and orientation of the user’s head and hands within a 4x4 meter area. Environments were developed using Unreal Engine 4, an open source gaming engine, to maximize usability for different audiences, learning objectives, and skill levels. Given the inherent fun of games and widespread interest in archaeology and cultural heritage, the results of this research are adaptable and applicable to learners of all ages in formal and informal educational settings. 

Abstract The prediction of reactor antineutrino spectra will play a crucial role as reactor experiments enter the precision era. The positron energy spectrum of 3.5 million antineutrino inverse beta decay reactions observed by the Daya Bay experiment, in combination with the fission rates of fissile isotopes in the reactor, is used to extract the positron energy spectra resulting from the fission of specific isotopes. This information can be used to produce a precise, data-based prediction of the antineutrino energy spectrum in other reactor antineutrino experiments with different fission fractions than Daya Bay. The positron energy spectra are unfolded to obtain the antineutrino energy spectra by removing the contribution from detector response with the Wiener-SVD unfolding method. Consistent results are obtained with other unfolding methods. A technique to construct a data-based prediction of the reactor antineutrino energy spectrum is proposed and investigated. Given the reactor fission fractions, the technique can predict the energy spectrum to a 2% precision. In addition, we illustrate how to perform a rigorous comparison between the unfolded antineutrino spectrum and a theoretical model prediction that avoids the input model bias of the unfolding method.