2,660 research outputs found
Generalised Swan modules and the D(2) problem
We give a detailed proof that, for any natural number n, each algebraic two
complex over C_n \times C_\infty is realised up to congruence by a geometric
complex arising from a presentation for the group.Comment: This is the version published by Algebraic & Geometric Topology on 24
February 200
The world significance of the Russian revolution
https://stars.library.ucf.edu/prism/1673/thumbnail.jp
Fear of Victimization Among Incarcerated Youths: Examining the Effects of Institutional “Neighborhood” Characteristics and Gang Membership
This study examines whether neighborhood factors found to predict fear of crime among the general population can be adapted to explain inmate fear of victimization inside juvenile correctional institutions. We test (a) whether institutional physical disorder, resident trust, and formal social control can predict fear of victimization, and (b) whether the importance of these factors for fear of victimization varies based on preincarceration street gang status. Using data from a large national sample of incarcerated youths, findings indicate non-gang members are more afraid of institutional victimization than gang members, confirming findings about levels of fear between these groups on the street. “Neighborhood” (institutional) physical disorder and resident trust predicted fear for gang and non-gang youths, whereas formal social control was significant only among non-gang youths. We discuss policy implications and directions for future research
Non-genetic inheritance, fertility and assisted reproductive technologies
The concept of non-genetic inheritance is gaining considerable attention in the assisted reproductive technology (ART) community due to the reported differences between children born from ART and those that are conceived naturally. It has been demonstrated that children conceived via ART have differences in fetal growth, birth weight, congenital abnormalities, cardiometabolic parameters, glucose homeostasis as well as changes to body composition compared to children conceived naturally. Although these changes may have a parental contribution and may be influenced by the pathology of infertility there is concern that the technologies themselves may play a role. In support of this, is emerging evidence that aspects of ART technology such as culture media formulation and insemination method can alter offspring phenotype. In addition it is also documented that exposure to environmental factors, such as toxins can impact on offspring gametogenesis such that these perturbations persist through generations. With the increasing use of ART and the development of new technologies it is vital that we understand whether ART can effect non-genetic inheritance so that we can optimise technology and prevent abnormal programming and its impact on all aspects of offspring health including fertility and a possible transmission to subsequent generations.Deirdre Zander-Fox, Nicole O McPherson, Michelle Lan
Building the Brazilian Academic Genealogy Tree
Along the history, many researchers provided remarkable contributions to
science, not only advancing knowledge but also in terms of mentoring new
scientists. Currently, identifying and studying the formation of researchers
over the years is a challenging task as current repositories of theses and
dissertations are cataloged in a decentralized way through many local digital
libraries. Following our previous work in which we created and analyzed a large
collection of genealogy trees extracted from NDLTD, in this paper we focus our
attention on building such trees for the Brazilian research community. For
this, we use data from the Lattes Platform, an internationally renowned
initiative from CNPq, the Brazilian National Council for Scientific and
Technological Development, for managing information about individual
researchers and research groups in Brazil
A categorical framework for the quantum harmonic oscillator
This paper describes how the structure of the state space of the quantum
harmonic oscillator can be described by an adjunction of categories, that
encodes the raising and lowering operators into a commutative comonoid. The
formulation is an entirely general one in which Hilbert spaces play no special
role. Generalised coherent states arise through the hom-set isomorphisms
defining the adjunction, and we prove that they are eigenstates of the lowering
operators. Surprisingly, generalised exponentials also emerge naturally in this
setting, and we demonstrate that coherent states are produced by the
exponential of a raising morphism acting on the zero-particle state. Finally,
we examine all of these constructions in a suitable category of Hilbert spaces,
and find that they reproduce the conventional mathematical structures.Comment: 44 pages, many figure
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Laser Path Planning and Power Control Strategies for Powder Bed Fusion Systems
In laser powder bed fusion additive manufacturing (AM) process, laser scan path, velocity,
and power are some of the most important parameters affecting the build quality. Control strategies
for laser path and power are implemented and tested on a prototype testbed based on industrial
standard G-code type programming language (referred to as AM G-code). The proposed AM G-code demonstrates different modes which define power-velocity-position profiles, and account for
the laser and scanner dynamics. AM G-code is interpreted into xy2-100 protocol and sent to the
galvo scanners and laser using a custom transmitter. The actual scan path is compared with the
commanded path during controlled tests. The proposed AM G-code interpreter modes are then
evaluated considering the measured dynamic system response, and further discussed in contrast to
commercial powder bed fusion systems.Mechanical Engineerin
MFA 2018
This catalog displays the work of the MFA Class of 2018 from the Sam Fox School at Washington University in St. Louis.https://openscholarship.wustl.edu/mfa_cat/1000/thumbnail.jp
MFA14 (MFA 2014)
Catalogue of a culminating student exhibition held at the Mildred Lane Kemper Art Museum, May 9-August 3, 2014. Contents include Introduction / Buzz Spector and Patricia Olynyk -- David Baker / Katie McGinnis -- Amber bloom ; Mop cask ; Sullen fluff ; Frothy Shiraz ; Aquatic jaws ; Smoking trumpets ; Lake feigned goose flap / Steve Byrnes -- Nathan Childs : the affliction a strange weight, the weight a plume of pain, the pain a shrill desire / Aaron Coleman -- Christopher Chrome / Marianne Rosa Laury -- Shayna Cohn / Cassie Jones -- Alyse Cole / Nicholas Tamarkin -- Joshua Cornelis -- Evan Crankshaw -- Seth Czaplewski / Emily J. Hanson -- Kathryn Douglas / Addoley Dzegede -- SkyMark mourning / Sean Fitzgibbons -- Raleigh Gardiner -- Liz Guilmet / Benjamin Meiners -- Adam Hogan / Cole Lu -- Cassie Jones : repetitive motion imageries / Jessica A. Hutchins -- Christy Kirk : birthright / Phillip B. Williams -- Marianne Rosa Laury / Christopher Chrome -- Cole Lu / Gillian Tobin -- Chris Lujan / Emily J. Hanson -- Ashley Milow / Nhu Nguyen -- Whitney Polich -- Jessie Shinn -- The chronotope / Rosalynn Stovall -- Tried to be everything ; Crazy little telephone ; Room to breathe / Daniel Stumeier -- Gillian Tobin -- Sopearb Touch / Gabriel Feldman -- Contributors -- About the Sam Fox School.https://openscholarship.wustl.edu/books/1011/thumbnail.jp
Differential Maintenance of Cortical and Cancellous Bone Strength Following Discontinuation of Bone-Active Agents
Osteoporotic patients treated with antiresorptive or anabolic agents experience an increase in bone mass and a reduction in incident fractures. However, the effects of these medications on bone quality and strength after a prolonged discontinuation of treatment are not known. We evaluated these effects in an osteoporotic rat model. Six-month-old ovariectomized (OVX) rats were treated with placebo, alendronate (ALN, 2 µg/kg), parathyroid hormone [PTH(1–34); 20 µg/kg], or raloxifene (RAL, 2 mg/kg) three times a week for 4 months and withdrawn from the treatments for 8 months. Treatment with ALN, PTH, and RAL increased the vertebral trabecular bone volume (BV/TV) by 47%, 53%, and 31%, with corresponding increases in vertebral compression load by 27%, 51%, and 31%, respectively (p < .001). The resulting bone strength was similar to that of the sham-OVX control group with ALN and RAL and higher (p < .001) with PTH treatment. After 4 months of withdrawal, bone turnover (BFR/BS) remained suppressed in the ALN group versus the OVX controls (p < .001). The vertebral strength was higher than in the OVX group only in ALN-treated group (p < .05), whereas only the PTH-treated animals showed a higher maximum load in tibial bending versus the OVX controls (p < .05). The vertebral BV/TV returned to the OVX group level in both the PTH and RAL groups 4 months after withdrawal but remained 25% higher than the OVX controls up to 8 months after withdrawal of ALN (p < .05). Interestingly, cortical bone mineral density increased only with PTH treatment (p < .05) but was not different among the experimental groups after withdrawal. At 8 months after treatment withdrawal, none of the treatment groups was different from the OVX control group for cortical or cancellous bone strength. In summary, both ALN and PTH maintained bone strength (maximum load) 4 months after discontinuation of treatment despite changes in bone mass and bone turnover; however, PTH maintained cortical bone strength, whereas ALN maintained cancellous bone strength. Additional studies on the long-term effects on bone strength after discontinuation and with combination of osteoporosis medications are needed to improve our treatment of osteoporosis. © 2011 American Society for Bone and Mineral Research
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