357 research outputs found
Results From a Mathematical Model for Human Monocytic Ehrlichiosis
Human monocytic ehrlichiosis (Ehrlichia chaffeensis), HME, is a tick-transmitted, rickettsial disease that has recently increased substantially in the USA from 142 reported cases in 2001 to 506 reported cases in 2005 [1,2]. There have been increasing surveys of tick populations over the past 10 years that have in turn supported the development of models for tick-borne disease transmission. Resulting HME models [3] suggest the importance of metapopulation structures, landscape environment parameters and periodic climatic effects in predicting the dynamics of HME transmission and the efficacy of control efforts, such as the reduction of the tick population through acaricide use. On this note, we describe a spatially-explicit model for HME transmission, and give a result illustrating the importance of migration in the dynamics of HME risk
Classroom Manipulative to Engage Students in Mathematical Modeling of Disease Spread: 1 + 1 = Achoo!
Infectious diseases ranging from the common cold to cholera affect our society physically, emotionally, ecologically, and economically. Yet despite their importance and impact, there remains a lack of effective teaching materials for epidemiology and disease ecology in K-12, undergraduate, and graduate curricula [2]. To address this deficit, we\u27ve developed a classroom lesson with three instructional goals: (1) Familiarize students on basic concepts of infectious disease ecology; (2) Introduce students to a classic compartmental model and its applications in epidemiology; (3) Demonstrate the application and importance of mathematical modeling as a tool in biology. The instructional strategy uses a game-based mathematical manipulative designed to engage students in the concepts of infectious disease spread. It has the potential to be modified for target audiences ranging from Kindergarten to professional schools in science, public health, policy, medical, and veterinarian programs. In addition, we\u27ve provided variations of the activity to enhance the transfer of fundamental concepts covered in the initial lesson to more complex concepts associated with vaccination and waning immunity. While 10 variations are presented here, the true number of directions in which the game might extend will only be limited by the imagination of its students [6]
Effects of chemical modification and nanotechnology on wood properties
As a green material, wood is widely used in building decoration, railway construction, and other fields. However, the wood itself has inherent defects of being easy to absorb water and deform, rot, and decrease in strength. The physical and mechanical strengths and stability of artificial fast-growing forest wood are even worse. As wood modification can improve the dimensional stability, durability, strength, and other properties of wood, it has been widely used. Chemical modification is the main method of wood modification. The development of nanotechnology has brought more possibilities for wood modification. Owing to the extensive literature available, this article summarizes the representative achievements of wood chemical modification and nanotechnology. The principle, production process, advantages, and disadvantages of various wood chemical modification methods were analyzed, compared, and evaluated. Finally, according to the application status of wood-modified materials, the problems existing in the current wood chemical modification methods and the application of nanotechnology, and the development trend in the future are analyzed
Ensuring Best Practice in Genomic Education and Evaluation: A Program Logic Approach
© Copyright © 2019 Nisselle, Martyn, Jordan, Kaunein, McEwen, Patel, Terrill, Bishop, Metcalfe and Gaff. Targeted genomic education and training of professionals have been identified as core components of strategies and implementation plans for the use of genomics in health care systems. Education needs to be effective and support the sustained and appropriate use of genomics in health care. Evaluation of education programs to identify effectiveness is challenging. Furthermore, those responsible for development and delivery are not necessarily trained in education and/or evaluation. Program logic models have been used to support the development and evaluation of education programs by articulating a logical explanation as to how a program intends to produce the desired outcomes. These are highly relevant to genomic education programs, but do not appear to have been widely used to date. To assist those developing and evaluating genomic education programs, and as a first step towards enabling identification of effective genomic education approaches, we developed a consensus program logic model for genomic education. We drew on existing literature and a co-design process with 24 international genomic education and evaluation experts to develop the model. The general applicability of the model to the development of programs was tested by program convenors across four diverse settings. Conveners reported on the utility and relevance of the logic model across development, delivery and evaluation. As a whole, their feedback suggests that the model is flexible and adaptive across university award programs, competency development and continuing professional development activities. We discuss this program logic model as a potential best practice mechanism for developing genomic education, and to support development of an evaluation framework and consistent standards to evaluate and report genomic education program outcomes and impacts
Properties and Applications of Bamboo Fiber-A Current-State-of-the Art
Fibers are used in many forms in engineering applications–one of the most common being used as reinforcement.
Due to its renewable short natural growth cycle and abundance of bamboo resources, bamboo fiber has attracted
attention over other natural fibers. Bamboo fiber has a complex natural structure but offers excellent mechanical
properties, which are utilized in the textile, papermaking, construction, and composites industry. However, bamboo fibers can easily absorb moisture and are prone to corrosion limiting their use in engineering applications.
Therefore, a better understanding of bamboo fiber is particularly important. This paper reviews all existing
research on the mechanical characterization of bamboo fiber with an emphasis on the extraction and treatment
techniques, and their effect on relevant properties. The chemical composition of bamboo fibers has also been
thoroughly investigated and presented herein. Current applications and future opportunities for bamboo fibers
in various fields have been presented with a focus on research needs. This work can serve as a reference for future
research on bamboo fiber
Optimized Discretization of Sources Imaged in Heavy-Ion Reactions
We develop the new method of optimized discretization for imaging the
relative source from two particle correlation functions. In this method, the
source resolution depends on the relative particle separation and is adjusted
to available data and their errors. We test the method by restoring assumed pp
sources and then apply the method to pp and IMF data. In reactions below 100
MeV/nucleon, significant portions of the sources extend to large distances (r >
20 fm). The results from the imaging show the inadequacy of common Gaussian
source-parametrizations. We establish a simple relation between the height of
the pp correlation function and the source value at short distances, and
between the height and the proton freeze-out phase-space density.Comment: 36 pages (inc. 9 figures), RevTeX, uses epsf.sty. Submitted to Phys.
Rev.
Lambda-proton correlations in relativistic heavy ion collisions
The prospect of using lambda-proton correlations to extract source sizes in
relativistic heavy ion collisions is investigated. It is found that the strong
interaction induces a large peak in the correlation function that provides more
sensitive source size measurements than two-proton correlations under some
circumstances. The prospect of using lambda-proton correlations to measure the
time lag between lambda and proton emissions is also studied.Comment: 4 pages, 3 figure, revtex style. Two short paragraphs are added at
referees' recommendations. Phys. Rev. Lett. in pres
How communication of genetic information within the family is addressed in genetic counselling: a systematic review of research evidence
Supporting consultands to communicate risk information with their relatives is key to obtaining the full benefits of genetic health care. To understand how health-care professionals address this issue in clinical practice and what interventions are used specifically to assist consultands in their communication of genetic information to appropriate relatives, we conducted a systematic review. Four electronic databases and four subject-specific journals were searched for papers published, in English, between January 1997 and May 2014. Of 2926 papers identified initially, 14 papers met the inclusion criteria for the review and were heterogeneous in design, setting and methods. Thematic data analysis has shown that dissemination of information within families is actively encouraged and supported by professionals. Three overarching themes emerged: (1) direct contact from genetic services: sending letters to relatives of mutation carriers; (2) professionals' encouragement of initially reluctant consultands to share relevant information with at-risk relatives and (3) assisting consultands in communicating genetic information to their at-risk relatives, which included as subthemes (i) psychoeducational guidance and (ii) written information aids. Findings suggest that professionals' practice and interventions are predicated on the need to proactively encourage family communication. We discuss this in the context of what guidance of consultands by professionals might be appropriate, as best practices to facilitate family communication, and of the limits to non-directiveness in genetic counselling
Imaging Sources with Fast and Slow Emission Components
We investigate two-proton correlation functions for reactions in which fast
dynamical and slow evaporative proton emission are both present. In such cases,
the width of the correlation peak provides the most reliable information about
the source size of the fast dynamical component. The maximum of the correlation
function is sensitive to the relative yields from the slow and fast emission
components. Numerically inverting the correlation function allows one to
accurately disentangle fast dynamical from slow evaporative emission and
extract details of the shape of the two-proton source.Comment: 13 pages, 4 figure
Thermal and Chemical Freeze-out in Spectator Fragmentation
Isotope temperatures from double ratios of hydrogen, helium, lithium,
beryllium, and carbon isotopic yields, and excited-state temperatures from
yield ratios of particle-unstable resonances in 4He, 5Li, and 8Be, were
determined for spectator fragmentation, following collisions of 197Au with
targets ranging from C to Au at incident energies of 600 and 1000 MeV per
nucleon. A deviation of the isotopic from the excited-state temperatures is
observed which coincides with the transition from residue formation to
multi-fragment production, suggesting a chemical freeze-out prior to thermal
freeze-out in bulk disintegrations.Comment: 14 pages, 10 figures, submitted to Phys. Rev. C, small changes as
suggested by the editors and referee
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