1,224 research outputs found

    Beef Cattle Lesson Plans: For use in the education of school-age children in the beef cattle industry

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    This project was initially created for use at Fort Hope in Arroyo Grande, California. It designs lesson plans created to teach children about the beef cattle industry. The project consists of lesson plans for three age groups: 7-9, 10-12, and 13-15. Each age group will learn various aspects about beef cattle, and lessons will increase in complexity as the children advance age groups. The groups will spend six days in lecture completing worksheets and activities, and on the seventh day, after completion of a review game, the children receive certificates. While the project was created specifically for the Fort Hope curriculum, it may be adapted for other uses

    The single phase alternating current series motor

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    The alternating current repulsion motor

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    Transient axonal glycoprotein-1 (TAG-1) and laminin-α1 regulate dynamic growth cone behaviors and initial axon direction in vivo

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    <p>Abstract</p> <p>Background</p> <p>How axon guidance signals regulate growth cone behavior and guidance decisions in the complex <it>in vivo </it>environment of the central nervous system is not well understood. We have taken advantage of the unique features of the zebrafish embryo to visualize dynamic growth cone behaviors and analyze guidance mechanisms of axons emerging from a central brain nucleus <it>in vivo</it>.</p> <p>Results</p> <p>We investigated axons of the nucleus of the medial longitudinal fascicle (nucMLF), which are the first axons to extend in the zebrafish midbrain. Using <it>in vivo </it>time-lapse imaging, we show that both positive axon-axon interactions and guidance by surrounding tissue control initial nucMLF axon guidance. We further show that two guidance molecules, transient axonal glycoprotein-1 (TAG-1) and laminin-α1, are essential for the initial directional extension of nucMLF axons and their subsequent convergence into a tight fascicle. Fixed tissue analysis shows that TAG-1 knockdown causes errors in nucMLF axon pathfinding similar to those seen in a laminin-α1 mutant. However, <it>in vivo </it>time-lapse imaging reveals that while some defects in dynamic growth cone behavior are similar, there are also defects unique to the loss of each gene. Loss of either TAG-1 or laminin-α1 causes nucMLF axons to extend into surrounding tissue in incorrect directions and reduces axonal growth rate, resulting in stunted nucMLF axons that fail to extend beyond the hindbrain. However, defects in axon-axon interactions were found only after TAG-1 knockdown, while defects in initial nucMLF axon polarity and excessive branching of nucMLF axons occurred only in laminin-α1 mutants.</p> <p>Conclusion</p> <p>These results demonstrate how two guidance cues, TAG-1 and laminin-α1, influence the behavior of growth cones during axon pathfinding <it>in vivo</it>. Our data suggest that TAG-1 functions to allow growth cones to sense environmental cues and mediates positive axon-axon interactions. Laminin-α1 does not regulate axon-axon interactions, but does influence neuronal polarity and directional guidance.</p

    Photolithographic micromolding of ceramics using plasma etched polyimide patterns

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    Features as fine as 4 μm with high aspect ratio were produced from ceria‐zirconia ceramic using a thick plasma‐etched polyimide layer as a micromold.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70009/2/APPLAB-63-24-3379-1.pd

    FluTE, a Publicly Available Stochastic Influenza Epidemic Simulation Model

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    Mathematical and computer models of epidemics have contributed to our understanding of the spread of infectious disease and the measures needed to contain or mitigate them. To help prepare for future influenza seasonal epidemics or pandemics, we developed a new stochastic model of the spread of influenza across a large population. Individuals in this model have realistic social contact networks, and transmission and infections are based on the current state of knowledge of the natural history of influenza. The model has been calibrated so that outcomes are consistent with the 1957/1958 Asian A(H2N2) and 2009 pandemic A(H1N1) influenza viruses. We present examples of how this model can be used to study the dynamics of influenza epidemics in the United States and simulate how to mitigate or delay them using pharmaceutical interventions and social distancing measures. Computer simulation models play an essential role in informing public policy and evaluating pandemic preparedness plans. We have made the source code of this model publicly available to encourage its use and further development

    The outcome of kidney transplants with multiple renal arteries

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    BACKGROUND: The use of grafts with multiple renal arteries has been considered a relative contraindication because of the increased incidence of vascular and urologic complications The aim of this study is to determine whether the kidney grafts with multiple arteries have any adverse effect upon post-transplant graft and patient survival. METHODS: We reviewed the records of 225 adult kidney transplants done consecutively at our institution. Twenty-nine patients (12.8%) had grafts with multiple renal arteries. We analyzed the incidence of post-transplant hypertension and vascular complications, mean creatinine levels, patient and graft survival. In 17 cases reconstruction was done as conjoined anastomosis between two arteries of equal size, and in 6 cases as end-to-side anastomosis of smaller arteries to larger arteries. Multiple anastomoses were performed in 6 cases. RESULTS: In one patient postoperative bleeding occurred. Mean systolic blood pressures, creatinine levels at first year and last follow-up and complication rates were all in acceptable ranges. There was no significant difference in graft and patient survival between multiple and single renal artery allografts. CONCLUSION: Although the kidney grafts with multiple renal arteries have been considered a relative contraindication because of the increased risk of complications, in our study allografts with multiple arteries were used successfully in kidney transplantation

    Evaluation of vaccination strategies for SIR epidemics on random networks incorporating household structure

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    This paper is concerned with the analysis of vaccination strategies in a stochastic SIR (susceptible → infected → removed) model for the spread of an epidemic amongst a population of individuals with a random network of social contacts that is also partitioned into households. Under various vaccine action models, we consider both household-based vaccination schemes, in which the way in which individuals are chosen for vaccination depends on the size of the households in which they reside, and acquaintance vaccination, which targets individuals of high degree in the social network. For both types of vaccination scheme, assuming a large population with few initial infectives, we derive a threshold parameter which determines whether or not a large outbreak can occur and also the probability and fraction of the population infected by such an outbreak. The performance of these schemes is studied numerically, focusing on the influence of the household size distribution and the degree distribution of the social network. We find that acquaintance vaccination can significantly outperform the best household-based scheme if the degree distribution of the social network is heavy-tailed. For household-based schemes, when the vaccine coverage is insufficient to prevent a major outbreak and the vaccine is imperfect, we find situations in which both the probability and size of a major outbreak under the scheme which minimises the threshold parameter are \emph{larger} than in the scheme which maximises the threshold parameter
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