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This study examined the relationship between patient performance on multiple memory measures and regional brain volumes using an FDA-cleared quantitative volumetric analysis program – Neuroreader™.
Ninety-two patients diagnosed with mild cognitive impairment (MCI) by a clinical neuropsychologist completed cognitive evaluations and underwent MR Neuroreader™ within 1 year of testing. Select brain regions were correlated with three widely used memory tests. Regression analyses were conducted to determine if using more than one memory measures would better predict hippocampal z-scores and to explore the added value of recognition memory to prediction models.
Memory performances were most strongly correlated with hippocampal volumes than other brain regions. After controlling for encoding/Immediate Recall standard scores, statistically significant correlations emerged between Delayed Recall and hippocampal volumes (rs ranging from .348 to .490). Regression analysis revealed that evaluating memory performance across multiple memory measures is a better predictor of hippocampal volume than individual memory performances. Recognition memory did not add further predictive utility to regression analyses.
This study provides support for use of MR Neuroreader™ hippocampal volumes as a clinically informative biomarker associated with memory performance, which is a critical diagnostic feature of MCI phenotype.
Clostridium difficile infections (CDIs) affect patients in hospitals and in the community, but the relative importance of transmission in each setting is unknown. We developed a mathematical model of C. difficile transmission in a hospital and surrounding community that included infants, adults and transmission from animal reservoirs. We assessed the role of these transmission routes in maintaining disease and evaluated the recommended classification system for hospital- and community-acquired CDIs. The reproduction number in the hospital was <1 (range: 0.16–0.46) for all scenarios. Outside the hospital, the reproduction number was >1 for nearly all scenarios without transmission from animal reservoirs (range: 1.0–1.34). However, the reproduction number for the human population was <1 if a minority (>3.5–26.0%) of human exposures originated from animal reservoirs. Symptomatic adults accounted for <10% transmission in the community. Under conservative assumptions, infants accounted for 17% of community transmission. An estimated 33–40% of community-acquired cases were reported but 28–39% of these reported cases were misclassified as hospital-acquired by recommended definitions. Transmission could be plausibly sustained by asymptomatically colonised adults and infants in the community or exposure to animal reservoirs, but not hospital transmission alone. Under-reporting of community-onset cases and systematic misclassification underplays the role of community transmission.
Salmonellosis is a leading cause of hospitalisation due to gastroenteritis in Australia. A previous source attribution analysis for a temperate state in Australia attributed most infections to chicken meat or eggs. Queensland is in northern Australia and includes subtropical and tropical climate zones. We analysed Queensland notifications for salmonellosis and conducted source attribution to compare reservoir sources with those in southern Australia. In contrast to temperate Australia, most infections were due to non-Typhimurium serotypes, with particularly high incidence in children under 5 years and strong seasonality, peaking in summer. We attributed 65.3% (95% credible interval (CrI) 60.6–73.2) of cases to either chicken meat or eggs and 15.5% (95% CrI 7.0–19.5) to nuts. The subtypes with the strongest associations with nuts were Salmonella Aberdeen, S. Birkenhead, S. Hvittingfoss, S. Potsdam and S. Waycross. All five subtypes had high rates of illness in children under 5 years (ranging from 4/100 000 to 23/100 000), suggesting that nuts may be serving as a proxy for environmental transmission in the model. Australia's climatic range allows us to conduct source attribution in different climate zones with similar food consumption patterns. This attribution provides evidence for environment-mediated transmission of salmonellosis in sub-tropical regions.
Understanding how seasonal patterns change from year to year is important for the management of infectious disease epidemics. Here, we present a mathematical formalization of the application of complex demodulation, which has previously only been applied in an exploratory manner in the context of infectious diseases. This method extracts the changing amplitude and phase from seasonal data, allowing comparisons between the size and timing of yearly epidemics. We first validate the method using synthetic data that displays the key features of epidemic data. In particular, we analyse both annual and biennial synthetic data, and explore the effect of delayed epidemics on the extracted amplitude and phase. We then demonstrate the usefulness of complex demodulation using national notification data for influenza in Australia. This method clearly highlights the higher number of notifications and the early peak of the influenza pandemic in 2009. We also identify that epidemics that peaked later than usual generally followed larger epidemics and involved fewer overall notifications. Our analysis establishes a role for complex demodulation in the study of seasonal epidemiological events.
Campylobacter sp. are a globally significant cause of gastroenteritis. Although rates of infection in Australia are among the highest in the industrialized world, studies describing campylobacteriosis incidence in Australia are lacking. Using national disease notification data between 1998 and 2013 we examined Campylobacter infections by gender, age group, season and state and territory. Negative binomial regression was used to estimate incidence rate ratios (IRRs), including trends by age group over time, with post-estimation commands used to obtain adjusted incidence rates. The incidence rate for males was significantly higher than for females [IRR 1·20, 95% confidence interval (CI) 1·18–1·21], while a distinct seasonality was demonstrated with higher rates in both spring (IRR 1·18, 95% CI 1·16–1·20) and summer (IRR 1·17, 95% CI 1·16–1·19). Examination of trends in age-specific incidence over time showed declines in incidence in those aged <40 years combined with contemporaneous increases in older age groups, notably those aged 70–79 years (IRR 1998–2013: 1·75, 95% CI 1·63–1·88). While crude rates continue to be highest in children, our findings suggest the age structure for campylobacteriosis in Australia is changing, carrying significant public health implications for older Australians.
From a population-based birth cohort of 245 249 children born in Western Australia during 1996–2005, we used linkage of laboratory and birth record datasets to obtain data including all respiratory syncytial virus (RSV) detections during infancy from a subcohort of 87 981 singleton children born in the Perth metropolitan area from 2000 to 2004. Using log binomial regression, we found that the risk of infant RSV detection increases with the number of older siblings, with those having ⩾3 older siblings experiencing almost three times the risk (relative risk 2·83, 95% confidence interval 2·46–3·26) of firstborn children. We estimate that 45% of the RSV detections in our subcohort were attributable to infection from an older sibling. The sibling effect was significantly higher for those infants who were younger during the season of peak risk (winter) than those who were older. Although older siblings were present in our cohort, they had very few RSV detections which could be temporally linked to an infant's infection. We conclude that RSV infection in older children leads to less severe symptoms but is nevertheless an important source of infant infection. Our results lend support to a vaccination strategy which includes family members in order to provide maximum protection for newborn babies.
Clostridium difficile is the principal cause of infectious diarrhoea in hospitalized patients. We investigated the incidence and risk factors for hospitalization due to C. difficile infection (CDI) in older Australians. We linked data from a population-based prospective cohort study (the 45 and Up Study) of 266 922 adults aged ⩾45 years recruited in New South Wales, Australia to hospitalization and death records for 2006–2012. We estimated the incidence of CDI hospitalization and calculated days in hospital and costs per hospitalization. We also estimated hazard ratios (HR) for CDI hospitalization using Cox regression with age as the underlying time variable. Over a total follow-up of 1 126 708 person-years, 187 adults had an incident CDI hospitalization. The crude incidence of CDI hospitalization was 16·6/100 000 person-years, with a median hospital stay of 6 days, and a median cost of AUD 6102 per admission. Incidence increased with age and year of follow-up, with a threefold increase for 2009–2012. After adjustment, CDI hospitalization rates were significantly lower in males than females (adjusted HR 0·6, 95% confidence interval 0·4–0·7). CDI hospitalization rates increased significantly over 2009–2012. There is a need to better understand the increasing risk of CDI hospitalization in women.
An innovative strategy to reduce dengue transmission uses the bacterium Wolbachia. We analysed the effects of Wolbachia on dengue transmission dynamics in the presence of two serotypes of dengue using a mathematical model, allowing for differences in the epidemiological characteristics of the serotypes. We found that Wolbachia has a greater effect on secondary infections than on primary infections across a range of epidemiological characteristics. If one serotype is more transmissible than the other, it will dominate primary infections and Wolbachia will be less effective at reducing secondary infections of either serotype. Differences in the antibody-dependent enhancement of the two serotypes have considerably less effect on the benefits of Wolbachia than differences in transmission probability. Even if the antibody-dependent enhancement rate is high, Wolbachia is still effective in reducing dengue. Our findings suggest that Wolbachia will be effective in the presence of more than one serotype of dengue; however, a better understanding of serotype-specific differences in transmission probability may be needed to optimize delivery of a Wolbachia intervention.
Estimates of the proportion of illness transmitted by food for different enteric pathogens are essential for foodborne burden-of-disease studies. Owing to insufficient scientific data, a formal synthesis of expert opinion, an expert elicitation, is commonly used to produce such estimates. Eleven experts participated in an elicitation to estimate the proportion of illnesses due to food in Australia for nine pathogens over three rounds: first, based on their own knowledge alone; second, after being provided with systematic reviews of the literature and Australian data; and finally, at a workshop where experts reflected on the evidence. Estimates changed significantly across the three rounds (P = 0·002) as measured by analysis of variance. Following the workshop in round 3, estimates showed smoother distributions with significantly less variation for several pathogens. When estimates were combined to provide combined distributions for each pathogen, the width of these combined distributions reflected experts’ perceptions of the availability of evidence, with narrower intervals for pathogens for which evidence was judged to be strongest. Our findings show that the choice of expert elicitation process can significantly influence final estimates. Our structured process – and the workshop in particular – produced robust estimates and distributions appropriate for inclusion in burden-of-disease studies.
Shepherd's beaked whale Tasmacetus shepherdi is one of the most poorly known cetaceans, whose diet has created some speculation given that its dentition differs greatly from that of most other beaked whales that are primarily teuthophagous. The few stomachs examined previously have given seemingly conflicting dietary information. In this paper the stomach contents of a freshly stranded adult female on Tristan da Cunha have been examined through identification of trace elements and genetic analysis of soft parts. At least 13 cephalopod and 8 fish species were identified from beaks and otoliths respectively, but only undigested fish remains were present in the stomach and identified genetically as Beryx splendens. Reconstituted masses totaled 8809 g for cephalopods and 17,554 g for fish, with four species (Histioteuthis atlantica, Taningia danae, Ommastrephes bartrami and Pholidoteuthis ‘A’) comprising 78.6% of the cephalopods and one species (B. splendens) comprising 87.4% of the fish eaten. It is concluded that Tasmacetus may alternately exploit fish and cephalopods, depending on the time of day and access to seamount or continental slope areas.
Materials science is an interdisciplinary field that examines the structure-property relationships in matter for its applications to many areas of science and engineering. Providing a means for intuitive development of understanding of these relationships by young learners and university undergraduates alike is critical. The effectiveness of an immersive low-cost 3D virtual reality (VR) environment was evaluated during a pilot study sponsored by the Center of Integrated Nanomechanical Systems (COINS) program. The 3D VR environment involves the use of a specialized display, sensors, computers, and immersive visual technology equipment. In collaboration with Cognitive Science investigators, our research focused on understanding the impact of the 3D VR environment on the visual ability to perceive structures in three dimensions and on quantifying the learning of COINS participants. The premise was to measure the learning of undergraduate participants in activities designed to evaluate the quality of the learning environment. Our investigation consisted of three stages in which participants learned about carbon nanotubes (CNTs) via traditional methods, physical models and virtual models. Traditional methods (2D projection graphs) were not appealing to participants and did not facilitate depth perception. Physical (ball-and-stick) models motivated participants by allowing interactivity but bond distance/angle measurements were tedious. Virtual models (3D models) offered complete manipulation, real-time measurements and the capability of mimicking realistic atomic forces (attractive/repulsive), giving the user a better insight into the structure of CNTs compared to previous methods. While immersive environments offer virtual models with some of the same benefits of physical models, it is the extended features (e.g. accurate distance representation, computer simulations capability and analysis tools for further investigations) that suggest such environments as effective learning tools for materials science education. Preliminary data analysis suggests that highly accurate perception of a molecular structure is facilitated by the use of immersive environments in which the operator may manipulate and measure important intrinsic information about the structure. Moreover, computer simulations of materials are of great scientific interest for technological progress. We are presently working on the development of the immersive 3D VR environment to perform atomistic simulations to enable scientists to perform accelerated calculations to solve problems with performance enhancements over conventional methods. Another important value in the immersive 3D VR environment lies in its expanded use for multi-disciplinary research, influencing structure-dependent applications, science learning, and design of nanodevices in fields such as materials science, chemistry, engineering, cognitive science, nanotechnology, and computer science among others.
We describe how students explore materials science concepts using animated interactive spreadsheets. An engaging pedagogy is created in the classroom using spreadsheets in a way that initially camouflages mathematical complexity, which can later be revealed and taught. Use of off-the-shelf spreadsheet software, including freeware makes these spreadsheets universally available.
There has been considerable interest in developing curricular programs and materials for teaching undergraduate courses in nanoscience in the United States and other developed countries in the past decade. Materials science and nanoscience research programs are growing in developing countries in South America, Africa and Asia. However, there still exists a significant disconnect between the research efforts in developing countries and undergraduate coursework. This report will focus on the teaching of an upper-division one semester lecture/laboratory course developed at James Madison University (JMU) called “The Science of the Small: An Introduction to the Nanoworld” taught in the School of Chemistry at the University of KwaZulu-Natal in Pietermaritzburg (UKZN-PMB), South Africa in 2009 through the Fulbright U.S. Scholar program. We report insights into the preparation needed to teach a cutting-edge laboratory course in South Africa. Also addressed will be some of the challenges of teaching an instrument-intensive laboratory course in a developing country, academic preparation of the typical native isiZulu-speaking UKZN undergraduate student compared to a typical U.S. student, and pre and post attitudes and content assessment of students who were enrolled in the course. Further discussed will be observations of post-apartheid science and math education in South Africa, and the beginning of a pilot program bringing South African undergraduate students to the U.S. to gain undergraduate research experience.
The absence of engineering from K-12 curricula and mainstream media often causes students to refer back to historical stereotypes regarding what engineers look like and the type of work they do. Such misconceptions may prevent high school students from pursuing engineering as a field of study and increase the need for engineering educational programs . Nano-Challenge is an outreach program that orients high school students to engineering through a one-year research internship. The program is held at the Center for Nanoscale Chemical, Electrical, Mechanical Manufacturing Systems (Nano-CEMMS) at the University of Illinois at Urbana-Champaign. A major focus of the program is to involve students from groups traditionally underrepresented in STEM fields and inform them about engineering earlier in their careers. An external program evaluation provides anecdotal information about the students’ experiences and gives feedback to inform program improvement.
In this study, the authors focused on children from 2-8 years of age and asked the simple question: what do engineers do? The number one response was: “I don’t know”, the number two response was “they drive a train.” While children are very familiar with professionals such as doctors, teachers, nurses, firefighters and policemen, they are rarely introduced to engineers. With this motivation, the authors developed a novel children’s book on engineering: Engineering Elephants. This book is an outreach tool that introduces children to the dynamic world of engineering design through roller coasters, fireworks, and a plethora of other exciting adventures. The book teaches children about relevant topics such as nanotechnology, renewable energy, and prosthetics by engaging them through an interactive journey of an elephant and his questioning of the world around him. The text was strategically developed using the language of science (asking questions) and introducing vocabulary relevant to science and math using a lyrical pattern. This presentation will highlight the development of this book as an instructional aid but also detail the response of various age groups to engineering activities presented as a companion to this book. In particular, an elementary school district in West Texas designed a 4-5th grade 3-week summer school curriculum around this book. Results from this study will have an impact on future generations by inspiring them to consider the exciting profession of engineering at an early age.
One consequence of “high stakes testing” in Tuscaloosa area schools has been exclusion of materials science faculty from any meaningful participation in middle and high school classrooms. Beyond the loss of resources from the classroom that Materials Science faculty and their students represent, this also has negative consequences for faculty wanting to build ties to schools to address NSF’s “broader impact” criteria. A group of STEM and Education faculty at The University of Alabama have been testing a team based approach designed to overcome the systemic constraints that prevent effective STEM/K-12 collaboration. Teams consisting of a high school teacher, a STEM faculty member, and a STEM graduate student have spent three weeks during summer 2010 to identify/develop and implement an inquiry based science experiments. The experiments are being tested on science campers at McWane Science Center prior to being assessed in the teachers’ classrooms during the fall semester. The experiments were chosen by each team and represent significant advances over those currently available in the schools. By setting a problem that no team member is able to solve alone an environment was produced where success requires meaningful collaboration. Preliminary qualitative evaluation indicates deeper understanding of the school environment by the STEM faculty and greater respect for the skills teachers bring to this endeavor. Successes in this pilot program have generated credibility with the local school district, opening the door to scaling up the project, and developing further positive ties. Incorporation of lead teachers from Alabama Science in Motion also allows the experiments developed to be widely disseminated throughout Alabama, as well as providing a mechanism to identify existing experiments to enhance.
Material science can be used to enrich secondary school curriculum and illuminate for students the connection between science and technology. Based on materials research being conducted at the University of Illinois, we have developed an interdisciplinary activity that integrates engineering with chemistry and material science.
Students investigate the behaviors of polymers by creating 3-dimensional (3-D) objects. Students can design objects that they “print” on the order of a cubic inch in about 20 minutes. The process students use to create these objects shows the application of engineering to material science in a novel and engaging way.
A photoactive chemical is initiated by the UV and blue light emitted from a data projector. This causes the formation of free radicals, which interact with molecules of a monomer and cause a polymerization reaction. The visual result of this reaction is that a liquid solidifies where students shine light. With black-and-white images, a data projector can direct the light to form any shape. This process can be easily modified to create true 3-D objects by adding another layer of the liquid to the top of the object and then shining the light again. With about 20 dollars worth of supplies from a hardware store, a simple staging device can be created to greatly simplify the process to create a 3-D printer in the classroom. Fabrication of this device can be done by students because the projector controls the x and y array of pixels; the object only needs to move in the z direction, unlike traditional rapid prototyping machines which control movement in the x, y, and z directions.
Results of integration into high school and college curriculum are discussed, and methods of integration and student perceptions of the activity are reported.
There is an acute and well-documented need for image processing of microscopy data in materials science regarding, for example, the characterization of the structure/property relationship of a given materials system. In our work, image processing has been used as a framework for conducting interdisciplinary team-based research that effectively integrates programs within the Center for Research on Interface Structures and Phenomena (CRISP) Materials Research Science and Engineering Center (MRSEC), e.g. research experiences for undergraduates (REU), teachers (RET) and high school fellowships. This research resulted from a five-year long collaboration between CRISP and the Physics and Computer Science Departments at Southern Connecticut State University (SCSU). This paper will focus on the implementation of team-based research experiences as a vehicle for interdisciplinary science and education. Representative results of several of the studies are presented and discussed.
The National Science Foundation (NSF) evaluates grant applications based on two criteria: intellectual merit and broader impact. The broader impact criterion (BIC), or the science outreach criterion, is intended to connect science, technology, engineering, and math (STEM) research to the general public, and has grown in its relevance for successful grants. A method to increase the competitiveness of a grant application and, in turn, the quality of science outreach programs is to suggest successful science outreach models for connecting scientists to the public. Science Saturdays is a fun science lecture series for the general public that is a simple, scalable, and transferable model. Its main mission is to introduce participants to excellent communicators of science and to shatter stereotypes about those who do science. It aims to inspire and motivate children as they traverse the STEM pipeline by emphasizing that science is fun. This paper discusses the elements needed to create this outreach program and the lessons learned from its development.