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Kinematic calibration of a class of parallel kinematic machines(PKM) with fewer than six degrees of freedom

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Science China(Technological Sciences) 2003年第5期46卷 515-526页

作者：黄田唐国宝李思维李亚 G.derek Chetwynd j.David Whitehouse School of Mechanical Engineering Tianjin University Tianjin 300072 China School of Engineering The University of Warwick Coventry CV4 7AL UK

By taking a 3-DOF translational milling machine as an example, this paper investigates the kinematic calibration of PKM systems with fewer than 6-DOF. The error mapping function is formulated in such a way that the geometric errors affecting the compensatable and uncompensatable pose errors can be separated. Based upon the previous investigation, a hierarchical approach to the geometric error identification is proposed. The compensation strategy is developed which is particularly suitable for the PKM systems with translational moving capability. The experiment has been carried out to verify the effectiveness of the proposed approach and the results show that the accuracy can be significantly improved.

关键词： parallel kinematic machines, kinematic calibration, degrees of freedom.

Sexual signal conspicuity is correlated with tail autotomy in an anoline lizard

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Current Zoology 2022年第1期68卷 129-132页

作者： Kelly LinWUTHRICH derek STOCK j.nelle B.TALAVERA Breanna j.PUTMAN Lindsey SWIERK Department of Biological Sciences Binghamton UniversityState University of New YorkBinghamtonNY 13902USA Department of Biology California State UniversityNorthridgeCA 91330-8303USA Department of Biology California State UniversitySan BernardinoCA 92407USA Department of Ecology and Evolutionary Biology University of California621 Young Drive SouthLos AngelesCA 90095-1606USA Department of Herpetology and Urban Nature Research Center Natural History Museum of Los Angeles CountyLos AngelesCA 90007USA School of Forestry and Environmental Studies Yale UniversityNew HavenCT 06511USA Amazon Conservatory for Tropical Studies IquitosLoreto 16001Peru The Morpho Institute Kansas CityMO 64113USA

Sexual selection favors conspicuous signals that animals can use to communicate with conspecifics and/or to attract ***,natural and sexual selection are often in opposition,as conspicuous sexual signals can also be detected by eavesdropping predators,forcing these signals to also evolve in light of natural selection(Andersson 1994).

关键词： signal evolve selection

Improving modeling of low-altitude particulate matter emission and dispersion:A cotton gin case study

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j.urnal of Environmental Sciences 2023年第11期133卷 8-22页

作者： Zij.ang Yang Michael N.Evans Michael D.Buser Cathleen j.Hapeman Alba Torrents derek P.Whitelock Department of Civil and Environmental Engineering University of Maryland College Park1173 Glenn L.Martin HallCollege ParkMaryland 20742United States Department of Geology University of Maryland College Park1212B Chemistry BuildingCollege ParkMaryland 20742United States Earth System Science Interdisciplinary Center 1120 Geology BuildingUniversity of MarylandCollege ParkMaryland 20742United States United States Department of Agriculture Agricultural Research ServiceOffice of National Programs5601 Sunnyside Ave(GWCC 4–2282)BeltsvilleMaryland 20705United States United States Department of Agriculture Agricultural Research ServiceHenry A.Wallace Beltsville Agricultural Research Center10300 Baltimore AvenueBeltsvilleMaryland 20705United States United States Department of Agriculture Agricultural Research ServiceSouthwestern Cotton Ginning Research LaboratoryPO Box 578Mesilla ParkNew Mexico 88047United States

Monitoring and modeling of airborne particulate matter(PM)from low-altitude sources is becoming an important regulatory target as the adverse health consequences of PM become better ***,application of models not specifically designed for simulation of PM from low-altitude emissions may bias *** address this problem,we describe the modification and validation of an air dispersion model for the simulation of lowaltitude PM dispersion from a typical cotton ginning *** found that the regulatory recommended model(AERMOD)overestimated pollutant concentrations by factors of 64.7,6.97 and 7.44 on average for PM 2.5,PM 10,and TSP,*** concentrations were negatively correlated with height(pj.stment and application of pre-existing models for risk assessment and development of remediation *** same approach may also be applied to improve simulations of other air pollutants and environmental conditions of concern.

关键词： Air quality Particulate matter Air dispersion modelling Cotton gin

Antimicrobial peptides and the gut microbiome in inflammatory bowel disease

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World j.urnal of Gastroenterology 2021年第43期27卷 7402-7422页

作者： j.hn Gubatan derek R Holman Christopher j.Puntasecca Danielle Polevoi Samuel j. Rubin Stephan Rogalla Division of Gastroenterology and Hepatology Stanford University School of MedicineRedwood CityCA 94063United States Department of Radiology Molecular Imaging Program at StanfordStanford UniversityStanfordCA 94305United States Stanford University School of Medicine Stanford UniversityStanfordCA 94063United States

Antimicrobial peptides(AMP)are highly diverse and dynamic molecules that are expressed by specific intestinal epithelial cells,Paneth cells,as well as immune cells in the gastrointestinal(GI)*** play critical roles in maintaining tolerance to gut microbiota and protecting against enteric *** that disruptions in tolerance to commensal microbiota and loss of barrier function play maj.r roles in the pathogenesis of inflammatory bowel disease(IBD)and converge on the function of AMP,the significance of AMP as potential biomarkers and novel therapeutic targets in IBD have been increasingly recognized in recent *** this frontier article,we discuss the function and mechanisms of AMP in the GI tract,examine the interaction of AMP with the gut microbiome,explore the role of AMP in the pathogenesis of IBD,and review translational applications of AMP in patients with IBD.

关键词： Antimicrobial peptides Inflammatory bowel disease Ulcerative colitis Crohn’s disease Gut microbiome Biomarkers

Biomolecular hydration dynamics probed with 2D-IR spectroscopy:From dilute solution to a macromolecular crowd

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Chinese Chemical Letters 2015年第4期26卷 435-438页

作者： j.hn T.King Evan j.Arthur derek G.Osborne Charles L.Brooks Ⅲ Kevin j.Kubarych Department of Chemistry University of Michigan LSA Biophysics University of Michigan Department of Materials Science and Engineering University of Illinois

Although it is well known that water is essential for biological function, it has been a challenge to determine how water behaves near biomacromolecular interfaces, and what role water plays in influencing the dynamics of the biochemical machinery. By adopting a vibrational labeling strategy coupled with ultrafast two-dimensional infrared （2D-IR） spectroscopy, it has recently become possible to study hydration dynamics, site specifically at the surface of proteins and model membranes. We review our recent progress in measuring hydration dynamics in contexts ranging from small-molecule solutes to biomacromolecules in dilute, viscous, and crowded environments.

关键词： Protein hydration dynamicsMembrane dynamicsUltrafast infrared spectroscopy

Mineralized collagen scaffolds fabricated with amniotic membrane matrix increase osteogenesis under inflammatory conditions

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Regenerative Biomaterials 2020年第3期7卷 247-258页

作者： Marley j.Dewey Eileen M.j.hnson Simona T.Slater derek j.Milner Matthew B.Wheeler Brendan A.C.Harley Department of Materials Science and Engineering University of Illinois at Urbana-Champaign110 Roger Adams Laboratory600 S.Mathews Ave.UrbanaIL 61801USA Department of Bioengineering University of Illinois at Urbana-Champaign110 Roger Adams Laboratory600 S.Mathews Ave.UrbanaIL 61801USA Department of Chemical and Biomolecular Engineering University of Illinois at Urbana-Champaign110 Roger Adams Laboratory600 S.Mathews Ave.UrbanaIL 61801USA Carl R.Woese Institute for Genomic Biology University of Illinois at Urbana-Champaign110 Roger Adams Laboratory600 S.Mathews Ave.UrbanaIL 61801USA Department of Animal Sciences University of Illinois at Urbana-Champaign110 Roger Adams Laboratory600 S.Mathews Ave.UrbanaIL 61801USA

Defects in craniofacial bones occur congenitally,after high-energy impacts,and during the course of treatment for stroke and *** inj.ries are difficult to heal due to the overwhelming size of the inj.ry area and the inflammatory environment surrounding the *** inflammatory response after inj.ry may greatly inhibit regenerative *** have developed mineralized collagen scaffolds that can induce osteogenic differentiation and matrix biosynthesis in the absence of osteogenic media or supplemental *** amniotic membrane is derived from placentas and has been recently investigated as an extracellular matrix to prevent chronic ***,we hypothesized that a mineralized collagen-amnion composite scaffold could increase osteogenic activity in the presence of inflammatory *** report mechanical properties of a mineralized collagen-amnion scaffold and investigated osteogenic differentiation and mineral deposition of porcine adipose-derived stem cells within these scaffolds as a function of inflammatory *** of amniotic membrane matrix promotes osteogenesis similarly to un-modified mineralized collagen scaffolds,and increases in mineralized collagen-amnion scaffolds under inflammatory ***,these findings suggest that a mineralized collagen-amnion scaffold may provide a beneficial environment to aid craniomaxillofacial bone repair,especially in the course of defects presenting significant inflammatory complications.

关键词： mineralized collagen scaffolds amniotic membrane inflammation stem cell osteogenesis

Error modeling, sensitivity analysis and assembly process of a class of 3-DOF parallel kinematic machines with parallelogram struts

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Science China(Technological Sciences) 2002年第5期45卷 467-476页

作者：黄田李亚唐国宝李思维赵兴玉 David.j.Whitehouse derek G.Chetewyn Xianping Liu School of Mechanical Engineering Tianjin University Tianjin 300072 China

This paper presents an error modeling methodology that enables the tolerance design, assembly and kinematic calibration of a class of 3-DOF parallel kinematic machines with parallelogram struts to be integrated into a unified framework. The error mapping function is formulated to identify the source errors affecting the uncompensable pose error. The sensitivity analysis in the sense of statistics is also carried out to investigate the influences of source errors on the pose accuracy. An assembly process that can effectively minimize the uncompensable pose error is proposed as one of the results of this investigation.

关键词： parallel kinematic machine, error modeling, sensitivity analysis, assembly process.

Measurement of Metabolic and Inflammatory Serum Markers and Immune Marker Gene Expression during Superovulation in Beef Cattle

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Open j.urnal of Animal Sciences 2021年第2期11卷 175-196页

作者： Alexandria P. Snider derek j. McLean Alfred R. Menino 112 Withycombe Hall Department of Animal and Rangeland Sciences Oregon State University Corvallis USA USDA ARS U.S. Meat Animal Research Center Livestock Biosystems Unit Clay Center NE USA Eunice Kennedy Shriver National Institute of Child Health and Human Development Bethesda MD USA

Health status of donor cows during superovulation is important to ensure optimal embryo quality at time of collection. Because nutritional and metabolic status impact embryo quality some form of nutritional supplementation is often provided before and during superovulation. OmniGen-AF® (OG) feeding has been shown to assist in the maintenance of animal health through regulation of metabolic status and balance and supporting aspects of immune function. We observed feeding donor cows OG decreased percent degenerate embryos recovered following superovulation increased serum progesterone concentration and improved in vitro embryo development. Evaluation of OG feeding on markers of metabolic function and inflammatory and immune function in beef cattle embryo donors are reported here. Similarly, cow metabolic and inflammatory response with repeated superovulation protocols is not known. Biomarkers to monitor and evaluate cow health during superovulation may provide management options to improve embryo recovery and quality. Twenty-four Angus cross-bred cattle were randomly assigned to four treatment groups, fed 0 or 56 g/hd/day for 49 days and superovulated with 200 or 400 mg Folltropin V (FSH). Blood was collected weekly for analyses. The protocol was repeated on all cows 90 - 120 d later with cows reassigned to their original groups. No differences (P > 0.10) were observed due to OG feeding or FSH dose on metabolic and inflammatory markers. Replicate exerted a significant effect where serum concentration of albumin, IL1β, IL6, PGE2 and leptin were lower (P<

关键词： Bovine Metabolism Estrous Cycle Follicle Stimulating Hormone Inflammation

Menaquinone (Vitamin K2) Enhancement of <i>Staphylococcus aureus</i>Biofilm Formation

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j.urnal of Biosciences and Medicines 2014年第1期2卷 26-32页

作者： derek T. Kirby j.yce M. Savage Balbina j. Plotkin Department of Microbiology and Immunology Midwestern University Downers Grove USA

During infection, Staphylococcus aureus is exposed to exogenous menaquinone which is essential for the human blood clotting cascade. The effect of exogenous menaquinone on S. aureus phenotypic expression is not known. To test whether menaquinone affects expression of virulence-associated phenotypes, methicillin-sensitive (MSSA) and -resistant (MRSA) S. aureus strains (n = 8) were grown in the presence of menaquinone (0.001 - 12 μg/ml). Capsule production, biofilm formation (plastic and fibronectin-coated microtiter plates) and carotenoid levels were determined spectrophotometrically after growth in Mueller Hinton broth (MH;24-hr, 37°C). All experiments were, at minimum, done in triplicate and repeated twice. Menaquinone at physiologic levels (0.01 μg/ml MH) significantly increased (p 0.05) biofilm formation on plastic in a manner that was bacterial population size dependent. In addition, menaquinone (0.05 - 4 μg/ml) significantly increased (p 0.05) biofilm formation on fibronectin-coated surfaces for four MSSA strains and one MRSA strain by two to six-fold as compared to medium controls. However, menaquinone had no effect on capsule production or cell-associated carotenoid levels. Menaquinone’s effect on biofilm formation on fibronectin-coated surfaces appears to be regulated by sarA. These findings are the first to demonstrate that a vitamin at concentrations reported in humans affects S. aureus virulence-associated phenotypes.

关键词： Quorum S. aureus Menaquinone Fibronectin Biofilm Capsule Plastic Adherence Carotenoid