435 research outputs found
A proposed program for specialized teacher training in physical education at the University of Richmond, Virginia
The purpose and scope of this paper 1s to show how the University of Richmond can (1) be of a more genuine service to the state and the community; {2) fulfill the desires and needs of the students who are pursuing a vocation in Physical Education; and (3) train better and prepare the student who desires to instruct and administer Health Education in our schools and communities
Mismatch repair defects and O6-methylguanine-DNA methyltransferase expression in acquired resistance to methylating agents in human cells.
Fifteen variants with >/=30-fold resistance to N-methyl-N-nitrosourea were isolated from the Burkitt's lymphoma Raji cell line. Eight had received a single treatment with a highly cytotoxic dose. The remainder, including the previously described RajiF12 cell line, arose following multiple exposures to initially moderate but escalating doses. Surprisingly, methylation resistance arose in three clones by reactivation of a previously silent O6-methylguanine-DNA methyltransferase gene. Five clones, including RajiF12, displayed the microsatellite instability and increased spontaneous mutation rates at the hypoxanthine-guanine phosphoribosyltransferase locus, consistent with deficiencies in mismatch repair. Defects in either the hMutSalpha or hMutLalpha mismatch repair complexes were identified in extracts of these resistant clones by in vitro complementation using extracts from colorectal carcinoma cell lines. Defects in hMutLalpha were confirmed by Western blot analysis. Remarkably, five methylation-resistant clones in which mismatch repair defects were demonstrated by biochemical assays did not exhibit significant microsatellite instability
ROCHESTER INSTITUTE OF TECHNOLOGY: ANALYZING STUDENT SUCCESS
RIT Online Learning courses have an overall course completion rate of 94%. For lower-division courses, the rate is 92%, undergraduate 93%, and graduate 96%. In this case study. we will share additional measurements we have used to monitor student success and describe strategies we have used to promote online discussion as a key component of effective online courses. We will share results from a large survey of our online students that shows the most interactive courses receive the most positive responses from students. The demographics of our online students have shifted to where almost half our online students are campus-based now. We believe our historical emphasis on interaction in our online courses is serving these new online students equally well, which suggests an important opportunity exists to expand online discussion to more campus-based courses
Vision as a compensatory mechanism for disturbance rejection in upwind flight
Recent experimental results demonstrate that flies possess a robust tendency to orient towards the frontally-centered focus of the visual motion field that typically occurs during upwind flight. We present a closed loop flight model, with a control algorithm based on feedback of the location of the visual focus of contraction, which is affected by changes in wind direction. The feasibility of visually guided upwind orientation is demonstrated with a model derived from current understanding of the biomechanics and sensorimotor computation of insects. The matched filter approach used to model the visual system computations compares extremely well with open-loop experimental data
A Control-Oriented Analysis of Bio-inspired Visuomotor Convergence
Insects exhibit incredibly robust closed loop fight dynamics in the face of uncertainties. A fundamental principle contributing to this unparalleled behavior is rapid processing and convergence of visual sensory information to fight motor commands via spatial wide-field integration, accomplished by retinal motion pattern sensitive interneurons (LPTCs) in the lobula plate portion of the visual ganglia. With in a control- theoretic frame work, models for spatially continuous retinal image flow and wide-field integration processing are developed, establishing the connection between image flow kernels (retinal motion pattern sensitivities) and the feedback terms they represent. It is shown that these out puts are sufficient to stabilize speed regulation and terrain following tasks. Hence, extraction of global retinal motion cues through computationally efficient wide-field integration processing provides a novel and promising methodology for utilizing visual sensory information in autonomous robotic navigation and fight control applications
The Pauli principle in a three-body cluster model and the momentum distributions after fragmentation of 6He and 11Li
We investigate two simple prescriptions to account for the Pauli principle in
a three-body cluster model employing a new method based on an adiabatic
hyperspherical expansion to solve the Faddeev equations in coordinate space.
The resulting wave functions are computed and compared. They are furthermore
tested on halo nuclei by calculations of momentum distributions and invariant
mass spectra arising after fragmentation of fast He and Li in
collisions with light targets. The prescriptions are very accurate and the
available measured quantities are remarkably well reproduced when final state
interactions are included.Comment: 18 pages, LaTex file, 15 postscript figures included using epsf.st
Neoarchean large igneous provinces on the Kaapvaal Craton in southern Africa re-define the formation of the Ventersdorp Supergroup and its temporal equivalents
U-Pb geochronology on baddeleyite is a
powerful technique that can be applied effectively
to chronostratigraphy. In southern
Africa, the Kaapvaal Craton hosts a wellpreserved
Mesoarchean to Paleoproterozoic
geological record, including the Neoarchean
Ventersdorp Supergroup. It overlies the Witwatersrand
Supergroup and its world-class
gold deposits. The Ventersdorp Supergroup
comprises the Klipriviersberg Group, Platberg
Group, and Pniel Group. However, the
exact timing of formation of the Ventersdorp
Supergroup is controversial. Here we present
2789 ± 4 Ma and 2787 ± 2 Ma U-Pb isotope dilution-
thermal ionization mass spectrometry
(ID-TIMS) baddeleyite ages and geochemistry
on mafic sills intruding the Witwatersrand Supergroup,
and we interpret these sills as feeders
to the overlying Klipriviersberg Group
flood basalts. This constrains the age of the
Witwatersrand Supergroup and gold mineralization
to at least ca. 2.79 Ga. We also report
2729 ± 5 Ma and 2724 ± 7 Ma U-Pb ID-TIMS
baddeleyite ages and geochemistry from a
mafic sill intruding the Pongola Supergroup
and on an east-northeast–trending mafic dike,
respectively. These new ages distinguish two
of the Ventersdorp Supergroup magmatic
events: the Klipriviersberg and Platberg. The
Ventersdorp Supergroup can now be shown
to initiate and terminate with two large igneous
provinces (LIPs), the Klipriviersberg
and Allanridge, which are separated by Platberg
volcanism and sedimentation. The age
of the Klipriviersberg LIP is 2791–2779 Ma,
and Platberg volcanism occurred at 2754–
2709 Ma. The Allanridge LIP occurred between
2709–2683 Ma. Klipriviersberg, Platberg,
and Allanridge magmatism may be
genetically related to mantle plume(s). Higher
heat flow and crustal melting resulted as a
mantle plume impinged below the Kaapvaal
Craton lithosphere, and this was associated
with rifting and the formation of LIPs
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