Use of cultured fibroblasts to study effects of hormones and growth factors and to compare growth of cells to animal growth

Fibroblasts in culture have been extensively used to study the effects of growth factors on growth of mammalian cells. They can be easily cultured and maintained for long periods of time. The objectives of these studies were to determine if viable fibroblasts could be obtained from skin of cattle and pigs, if serum, hormones or growth factors influenced the growth of these cells and if fibroblast growth was indicative of donor animal performance;A technique for acquiring a skin biopsy from ear tissue is detailed. Fibroblasts were observed to grow from this tissue explant and the cells responded to the presence of one or ten percent serum by increasing uptake of thymidine and leucine compared with cells in serum-free medium;The growth response of bovine fibroblasts to dexamethasone, estradiol, growth hormone, insulin or thyroxine additions in serum-free or medium containing 1% serum was examined. None of these hormones appeared to be a primary determinant of fibroblast growth, as measured by thymidine and leucine incorporation;Growth response of bovine fibroblasts to epidermal growth factor and insulin-like growth factor-I and combinations of hormones with growth factors was also studied. These peptides increased thymidine and leucine incorporation in the presence of one percent serum. Addition of hormones with growth factors did not dramatically improve growth;Growth of cattle and swine was compared with growth of their cells in culture. Samples were collected from newborn calves to aged cows and pigs from birth to five months of age. The potential for animal growth was expressed in cultured fibroblasts but the measurements of growth of the cells did not always predict live weight at a future point in time. As age of animals increased and growth rate relative to body weight decreased, outgrowth from the explant decreased, resulting in a negative linear relationship between outgrowth of cells from the explant and age

Internal Damage Detection and Assessment in Beams Using Experimental Natural Frequencies

This study investigated the frequency response of a cantilever beam with the intent of establishing a reliable nondestructive method of damage detection. The test specimens were 12 aluminum 2024 T3 beams, each identical except for a unique, eccentrically located notch, and one reference notchless beam. The machined notches varied in length and location to simulate varying degrees of damage. Laser doppler vibrometry enabled the data acquisition. The changes in natural frequencies were correlated to notch length and notch location. A comparison of eccentric and centered notch influence on the natural frequencies also is discussed

Lifelong Multi-Agent Path Finding in Large-Scale Warehouses

Multi-Agent Path Finding (MAPF) is the problem of moving a team of agents to their goal locations without collisions. In this paper, we study the lifelong variant of MAPF, where agents are constantly engaged with new goal locations, such as in large-scale automated warehouses. We propose a new framework Rolling-Horizon Collision Resolution (RHCR) for solving lifelong MAPF by decomposing the problem into a sequence of Windowed MAPF instances, where a Windowed MAPF solver resolves collisions among the paths of the agents only within a bounded time horizon and ignores collisions beyond it. RHCR is particularly well suited to generating pliable plans that adapt to continually arriving new goal locations. We empirically evaluate RHCR with a variety of MAPF solvers and show that it can produce high-quality solutions for up to 1,000 agents (= 38.9\% of the empty cells on the map) for simulated warehouse instances, significantly outperforming existing work.Comment: Published at AAAI 202

The Scientific Teaching Practices Survey for Undergraduate STEM Courses

The National Academies Summer Institutes on Undergraduate Education (SI) is a faculty development workshop in which STEM instructors are trained in the Scientific Teaching (ST) pedagogy and encouraged to implement its practices at their home institutions. While participants generally report positive experiences at the SI, it remains unclear how these experiences affect instructors’ teaching practices and associated student outcomes. As part of a larger effort to evaluate the SI, we developed a survey to gauge the frequencies of ST practices that could occur in undergraduate STEM courses. The ST Practices Survey is derived from the observable teaching practices described in the Scientific Teaching taxonomy (Couch et al., 2015). During survey development, we conducted interviews with a panel of experts, instructors, and students, and this input was used to make iterative revisions to the survey. After finalizing the survey, we administered the survey at 9 institutions with 62 instructors and 64 courses, with both instructors and students completing the survey for a given course. In this seminar, we will discuss the development, validity, reliability, factor structure, and implementation of the ST Practices Survey. (abstract only

The Scientific Teaching Practices Survey for Undergraduate STEM Courses

The National Academies Summer Institutes on Undergraduate Education (SI) is a faculty development workshop in which STEM instructors are trained in the Scientific Teaching (ST) pedagogy and encouraged to implement its practices at their home institutions. While participants generally report positive experiences at the SI, it remains unclear how these experiences affect instructors’ teaching practices and associated student outcomes. As part of a larger effort to evaluate the SI, we developed a survey to gauge the frequencies of ST practices that could occur in undergraduate STEM courses. The ST Practices Survey is derived from the observable teaching practices described in the Scientific Teaching taxonomy (Couch et al., 2015). During survey development, we conducted interviews with a panel of experts, instructors, and students, and this input was used to make iterative revisions to the survey. After finalizing the survey, we administered the survey at 9 institutions with 62 instructors and 64 courses, with both instructors and students completing the survey for a given course. In this seminar, we will discuss the development, validity, reliability, factor structure, and implementation of the ST Practices Survey. (abstract only

Perspectives on next steps in classification of oro-facial pain - part 1: role of ontology

The purpose of this study was to review existing principles of oro-facial pain classifications and to specify design recommendations for a new system that would reflect recent insights in biomedical classification systems, terminologies and ontologies. The study was initiated by a symposium organised by the International RDC/TMD Consortium Network in March 2013, to which the present authors contributed. The following areas are addressed: problems with current classification approaches, status of the ontological basis of pain disorders, insufficient diagnostic aids and biomarkers for pain disorders, exploratory nature of current pain terminology and classification systems, and problems with prevailing classification methods from an ontological perspective. Four recommendations for addressing these problems are as follows: (i) develop a hypothesis-driven classification structure built on principles that ensure to our best understanding an accurate description of the relations among all entities involved in oro-facial pain disorders; (ii) take into account the physiology and phenomenology of oro-facial pain disorders to adequately represent both domains including psychosocial entities in a classification system; (iii) plan at the beginning for field-testing at strategic development stages; and (iv) consider how the classification system will be implemented. Implications in relation to the specific domains of psychosocial factors and biomarkers for inclusion into an oro-facial pain classification system are described in two separate papers

Sustaining Professional Growth with a Side-to-Side Pedagogy: A Qualitative Case Study of the National Writing Project Focused on Seven Teacher Consultants

In a qualitative case study, this research focused on the professional growth of National Writing Project (NWP) Teacher Consultants (TCs). The overarching question, In what ways have experiences with the National Writing Project sustained the professional growth of NWP Teacher Consultants? guided an inquiry of seven TCs—teaching in grades three through university and representing seven sites from diverse regions—who had developed an Expressive Writing Pedagogy. Multiple interviews, videos, and artifacts allowed an extensive exploration of the conditions, contexts, supports, and challenges each experienced as they developed their classroom pedagogies and furthered their leadership over time. Findings included a rich description of the seven nested cases and a discussion of the following themes: a special kind of teacher, side-to-side pedagogy, authentic professional learning, conditions for success, and thriving in community