711 research outputs found
Preparation of Translationally Competent tRNA by Direct Chemical Acylation
Nonsense codon suppression for unnatural amino acid incorporation requires the preparation of a suppressor aminoacyl-tRNA. Chemical acylation strategies are general but inefficient and arduous. A recent report (J. Am. Chem. Soc. 2007, 129, 15848) showed acylation of RNA mediated by lanthanum(III) using amino acid phosphate esters. The successful implementation of this methodology to full-length suppressor tRNA is described, and it is shown that the derived aminoacyl-tRNA is translationally competent in Xenopus oocytes
Federal Prosecution of State and Local Officials Using Honest Services Mail Fraud: Where\u27s the Line?
Although there is little dispute that the mail fraud statute has become a valuable part of a federal prosecutor\u27s arsenal, for years legal scholars have debated the extent to which the mail fraud statute should be used to prosecute corrupt state and local officials. In recent years, largely in response to the large number of high profile honest services fraud prosecutions, even members of the mainstream news media are beginning to seek guidance regarding the definition of honest services mail fraud. As noted by Professor George Brown, though the controversy over whether the national government should be responsible for prosecuting state and local corruption is not new, it seems increasingly important as the Supreme Court expands the reach of its federalism decisions, sometimes applying the \u27new federalism\u27 with a vengeance. In recent months, the Supreme Court has broken its silence on this issue and appears poised to consider this issue for the first time in twenty-two years
Does it help teaching? Instructorsâ perceptions of a technology enhanced standards-based educational program
Recent accountability movements in the education world gave rise to standards-based curriculum, which provides a teaching and learning environment with high quality instructional materials. An example to such learning environment is Cisco Certified Network Associate (CCNA) program. This study investigates high school teachersâ perceptions and experiences of CCNA program in their classrooms. 357 high school teachers in the United States who teach in the CCNA program completed an online survey measuring their perceptions about standards-based curriculum and testing. The results show that teachers generally accept standards-based curriculum and testing as a teaching tool, spend less time on student feedback and would like to see some features of the curriculum applied to other regular high school subjects such as mathematics and science
A comparison of agricultural systems at the Allee Research Center
The petrochemical-dependent agriculture that developed in the export-oriented economy of the 1970\u27s proved vulnerable to high energy costs and volatile export markets as well as detrimental to soil and water resources. This project was designed to compare a petrochemical-based, high-tillage, low-management cropping system (System I) with two alternative systems: a ridge-till, reduced fertilizer and pesticide, high-management system (System II) and a rotational, low-pesticide, low-fertilizer conventional tillage system (System III)
Early emergence of CD19-negative human antibody secreting cells at the plasmablast to plasma cell transition
Long-lived human plasma cells (PCs) play central roles in immunity and autoimmunity and are enriched amongst the subpopulation of CD19-negative human PCs. However, whether human CD19-negative PCs are necessarily âłagedâł cells that have gradually lost CD19 expression is not known. Assessing peripheral blood samples at steady state and during the acute response to influenza vaccination in healthy donors we identify the presence of phenotypic CD19-negative plasmablasts, the proliferative precursor state to mature PCs, and demonstrate by ELISpot that these are antibody-secreting cells (ASCs). During the acute response to influenza vaccination CD19-positive, CD19-low and CD19-negative ASCs secrete vaccine-specific antibody and show linked IGHV repertoires. To address precursor/product relationships we employ in vitro models which mimic both T-dependent and T-independent differentiation finding that the CD19-negative state can be established at the plasmablast to PC transition, that CD19-negative PCs increase as a percentage of surviving PCs in vitro, and that CD19-negative and CD19-positive PCs can be maintained independently. These data provide proof-of-principle for the view that newly generated ASCs can acquire a mature PC phenotype accompanied by loss of CD19 expression at an early stage of differentiation and that âłagingâł is not an obligate requirement for a CD19-negative state to be established
The minority of three-game: an experimental and theoretical analysis
We report experimental results on the minority of three-game, where three players choose one of two alternatives and the most rewarding alternative is the one chosen by a single player. This coordination game has many asymmetric equilibria in pure strategies that are non-strict and payoff-asymmetric and a unique symmetric mixed strategy equilibrium in which each playerâs behavior is based on the toss of a fair coin. This straightforward behavior is predicted by equilibrium selection, impulse-balance equilibrium, and payoff-sampling equilibrium. Experimental participants rely on various decision rules, and only a quarter of them perfectly randomize
A growing global networkâs role in outbreak response: AFHSC-GEIS 2008-2009
A cornerstone of effective disease surveillance programs comprises the early identification of infectious threats and the subsequent rapid response to prevent further spread. Effectively identifying, tracking and responding to these threats is often difficult and requires international cooperation due to the rapidity with which diseases cross national borders and spread throughout the global community as a result of travel and migration by humans and animals. From Oct.1, 2008 to Sept. 30, 2009, the United States Department of Defenseâs (DoD) Armed Forces Health Surveillance Center Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) identified 76 outbreaks in 53 countries. Emerging infectious disease outbreaks were identified by the global network and included a wide spectrum of support activities in collaboration with host country partners, several of which were in direct support of the World Health Organizationâs (WHO) International Health Regulations (IHR) (2005). The network also supported military forces around the world affected by the novel influenza A/H1N1 pandemic of 2009. With IHR (2005) as the guiding framework for action, the AFHSC-GEIS network of international partners and overseas research laboratories continues to develop into a far-reaching system for identifying, analyzing and responding to emerging disease threats
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