267 research outputs found
Experimental flow properties in the wake of a 120 deg cone at Mach number 2.20
Supersonic flow characteristics in wake of blunt cone
Cardiovascular gene expression profiles of dioxin exposure in zebrafish embryos
Author Posting. Ā© The Authors, 2005. This is the author's version of the work. It is posted here by permission of Society of Toxicology for personal use, not for redistribution. The definitive version was published in Toxicological Sciences 85 (2005): 683-693, doi:10.1093/toxsci/kfi116.2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a widespread environmental contaminant
that causes altered heart morphology, circulatory impairment, edema, hemorrhage, and early life
stage mortality in fish. TCDD toxicity is largely dependent upon the aryl hydrocarbon receptor,
but understanding of the molecular mechanism of cardiovascular embryotoxicity remains
incomplete. In order to identify genes potentially involved in cardiovascular impacts, we
constructed custom cDNA microarrays consisting of 4,896 zebrafish adult heart cDNA clones
and over 200 genes with known developmental, toxicological, and housekeeping roles. Gene
expression profiles were obtained for 3-day old zebrafish following early embryonic exposure to
either 0.5 or 5.0 nM TCDD. 516 clones were significantly differentially expressed (p-value <
0.005) under at least one treatment condition; 123 high-priority clones were selected for further
investigation. CYP1A, CYP1B1, and other members of the AHR gene battery, were strongly
and dose-dependently induced by TCDD. Importantly, altered expression of cardiac sarcomere
components, including cardiac troponin T2 and multiple myosin isoforms, was consistent with
the hypothesis that TCDD causes dilated cardiomyopathy. Observed increases in expression
levels of mitochondrial energy transfer genes also may be related to cardiomyopathy. Other
TCDD-responsive genes included fatty acid and steroid metabolism enzymes, ribosomal and
signal transduction proteins, and 18 ESTs with no known protein homologs. As the first broadscale
study of TCDD-modulated gene expression in a non-mammalian system, this work
provides an important perspective on mechanisms of TCDD toxicity.This work was supported by
funding from the National Institutes of Health
Two-stage evolution of mantle peridotites from the Stalemate Fracture Zone, northwestern Pacific
This paper reports the results of a mineralogical study of 14 mantle peridotite samples dredged in 2009 from the eastern slope of the northwestern segment of the Stalemate Ridge in the northwestern Pacific during cruise SO201-KALMAR Leg 1b of the R/V Sonne. The sample collection included four serpentinized and silicified dunites and ten variably serpentinized lherzolites. The compositions of primary minerals (clinopyroxene, orthopyroxene, and spinel) change systematically from the lherzolites to dunites. Spinel from the lherzolites shows higher Mg# and lower Cr# values (0.65-0.68 and 0.26-0.33, respectively) compared with spinel from the dunites (Mg# = 0.56-0.64 and Cr# = 0.38-0.43). Clinopyroxene from the lherzolites is less magnesian (Mg# = 91.7-92.4) than clinopyroxene from dunite sample DR37-3 (Mg# = 93.7). Based on the obtained data, it was concluded that the lherzolites of the Stalemate Fracture Zone were derived by 10-12% near-fractional melting of a DMM-type depleted mantle reservoir beneath the Kula-Pacific spreading center. The dunites were produced by interaction of residual lherzolites with sodium- and titaniumrich melt and are probably fragments of a network of dunite channels in the shallow mantle. The moderately depleted composition of minerals clearly distinguishes the lherzolites from the strongly depleted peridotites of the East Pacific Rise and indicates the existence of slow-spreading mid-ocean ridges in the Pacific Ocean during the Cretaceous-Paleogene
A tale of two towns: A comparative study exploring the possibilities and pitfalls of social capital among people seeking recovery from substance misuse
Background: Social capital has become an influential concept in debating and understanding the modern world. Within the drug and alcohol sector, the concept of ārecovery capitalā has gained traction with researchers suggesting that people who have access to such capital are better placed to overcome their substance use-related problems than those who do not (Cloud and Granfield, 2008), leading to requests for interventions that focus on building social capital networks (Neale & Stevenson, 2015). While accepting that the concept of social capital has enormous potential for addressing the problems associated with drug use, this paper also considers its ādark sideā. Methods: Data were drawn from semi-structured interviews with 180 participants including 135 people who use drugs and 45 people who formerly used drugs. Results: High levels of trust, acquired through the establishment of dense social networks, are required to initiate recovery. However, these āstrong bondsā may also lead to the emergence of what is perceived by others as an exclusive social network that limits membership to those who qualify and abide by the ārulesā of the recovery community, particularly around continuous abstinence. Conclusions: Depending on the nature of the networks and the types of links participants have into them being socially connected can both inhibit and encourage recovery. Therefore, the successful application of social capital within the drugs and alcohol field requires a consideration of not only the presence or absence of social connections but their nature, the value they produce, and the social contexts within which they are developed
Comparing Skill Acquisition Under Varying Onsets of Differential Reinforcement: A Preliminary Analysis
The purpose of the current study was to evaluate the effect of implementing differential reinforcement at different times relative to the onset of teaching new skills to learners with autism spectrum disorder. Specifically, we first determined the most efficient differential reinforcement arrangement for each participant. Using the most efficient arrangement, we evaluated if differential reinforcement from the immediate onset, early onset, or late onset is the most efficient for learners to acquire a new skill. Three children diagnosed with autism spectrum disorder who have a history of receiving intervention based on the principles of applied behavior analysis participated in this study. The immediate onset of differential reinforcement resulted in the most efficient instruction in 6 of 7 comparisons. The results are discussed in light of previous studies and suggestions for future research are provided
An Evaluation of Parent Preference for Prompting Procedures
Parent participation in intervention can enhance intervention efficacy and promote generalization of skills across settings. Thus, parents should be trained to implement behavioral interventions. The purpose of the current investigation was to evaluate parent preference for and acceptability of 3 commonly used prompting procedures. We trained parents of children with disabilities to use 3 empirically validated prompting strategies (i.e., leastātoāmost, mostātoāleast, and a progressiveāprompt delay). Once the parent reached the mastery criteria with each prompting procedure, we evaluated his/her preference for each of the procedures using a concurrentāchains arrangement. We also measured treatment acceptability of all procedures throughout the study. All participants met the mastery criteria for each of the prompting procedures and showed a preference for leastātoāmost prompting. Results suggest parents\u27 acceptability of procedures prior to training were different than posttraining/postāchild practice. In addition, acceptability rating scores obtained at the end of the investigation corresponded to preference of intervention during the concurrentāchains arrangement. The results demonstrate the benefits of objective measures for studying preference for behavioral, skillāacquisition procedures
A Critical Review on the Structural Health Monitoring Methods of the Composite Wind Turbine Blades
With increasing turbine size, monitoring of blades becomes increasingly im-portant, in order to prevent catastrophic damages and unnecessary mainte-nance, minimize the downtime and labor cost and improving the safety is-sues and reliability. The present work provides a review and classification of various structural health monitoring (SHM) methods as strain measurement utilizing optical fiber sensors and Fiber Bragg Gratings (FBGās), active/ pas-sive acoustic emission method, vibrationābased method, thermal imaging method and ultrasonic methods, based on the recent investigations and prom-ising novel techniques. Since accuracy, comprehensiveness and cost-effectiveness are the fundamental parameters in selecting the SHM method, a systematically summarized investigation encompassing methods capabilities/ limitations and sensors types, is needed. Furthermore, the damages which are included in the present work are fiber breakage, matrix cracking, delamina-tion, fiber debonding, crack opening at leading/ trailing edge and ice accre-tion. Taking into account the types of the sensors relevant to different SHM methods, the advantages/ capabilities and disadvantages/ limitations of repre-sented methods are nominated and analyzed
The Institutional Framework for Doing Sports Business: Principles of EU Competition Policy in Sports Markets
The importance of poetry, hip-hop, and philosophy for an enlisted aviator in the USAF (2000ā2004) flying in support of Operation Enduring Freedom and Operation Iraqi Freedom
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