6,172 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
Rotary solenoid shutter drive assembly and rotary inertia damper and stop plate assembly
A camera shutter assembly composed of a pair of superposed opaque planar shutter blades, each having an aperture and being arranged for reciprocal linear movement is disclosed. A pair of rotary solenoids, each connected to one of the blades by a linkage and arranged to be actuated separately at a predetermined interval is provided. An inertia damper and stop plate is built into each solenoid to prevent rebound
The Effects of Federalism and Privatization on Productivity in Chinese Firms
This study offers empirical evidence about how the structure of government and private ownership affects productivity in Chinese firms. It uses the microdata of China's most recent decennial industrial census, covering all of the 23,000 large and medium industrial firms operating in China during 1995. The results show that government decentralization – 'federalism' – plays an important role in improving the performance of not just collective firms, but also state-owned and mixed public/private ownership firms. This result is strongly confirmatory of much of the recent theoretical work on transition economies that posits a key role for government in the efficient operation of markets. Privatization makes a big difference in performance for firms administered at the federal level, especially state-owned enterprises. Private ownership also makes a large difference for wholly foreign-owned firms, nearly all located in special districts. In local jurisdictions, however, there is little difference in productivity across the various nonstate ownership types, supporting the argument that the regulatory environment played a critical role in successful business performance.china productivity microdata ownership decentralization
State Case Studies of Infant and Early Childhood Mental Health Systems: Strategies for Change
Profiles efforts to develop mental health identification and intervention systems for children up to age 5 in Colorado, Indiana, Massachusetts, and Rhode Island. Examines hurdles, reform potentials, and lessons learned, including the role of partnerships
The exp-log normal form of types
Lambda calculi with algebraic data types lie at the core of functional
programming languages and proof assistants, but conceal at least two
fundamental theoretical problems already in the presence of the simplest
non-trivial data type, the sum type. First, we do not know of an explicit and
implemented algorithm for deciding the beta-eta-equality of terms---and this in
spite of the first decidability results proven two decades ago. Second, it is
not clear how to decide when two types are essentially the same, i.e.
isomorphic, in spite of the meta-theoretic results on decidability of the
isomorphism.
In this paper, we present the exp-log normal form of types---derived from the
representation of exponential polynomials via the unary exponential and
logarithmic functions---that any type built from arrows, products, and sums,
can be isomorphically mapped to. The type normal form can be used as a simple
heuristic for deciding type isomorphism, thanks to the fact that it is a
systematic application of the high-school identities.
We then show that the type normal form allows to reduce the standard beta-eta
equational theory of the lambda calculus to a specialized version of itself,
while preserving the completeness of equality on terms. We end by describing an
alternative representation of normal terms of the lambda calculus with sums,
together with a Coq-implemented converter into/from our new term calculus. The
difference with the only other previously implemented heuristic for deciding
interesting instances of eta-equality by Balat, Di Cosmo, and Fiore, is that we
exploit the type information of terms substantially and this often allows us to
obtain a canonical representation of terms without performing sophisticated
term analyses
Vibration isolation for line of sight performance improvement
Diagrams of the Reaction Wheel Assembly (RWA) are presented along with charts and graphs illustrating jitter error model, induced vibration tests, radial displacement transfer function, and axial displacement power spectra density. The RWA isolator specification requirements are listed
Probing the role of the cation–π interaction in the binding sites of GPCRs using unnatural amino acids
We describe a general application of the nonsense suppression methodology for unnatural amino acid incorporation to probe drug–receptor interactions in functional G protein-coupled receptors (GPCRs), evaluating the binding sites of both the M2 muscarinic acetylcholine receptor and the D2 dopamine receptor. Receptors were expressed in Xenopus oocytes, and activation of a G protein-coupled, inward-rectifying K^+ channel (GIRK) provided, after optimization of conditions, a quantitative readout of receptor function. A number of aromatic amino acids thought to be near the agonist-binding site were evaluated. Incorporation of a series of fluorinated tryptophan derivatives at W6.48 of the D2 receptor establishes a cation–π interaction between the agonist dopamine and W6.48, suggesting a reorientation of W6.48 on agonist binding, consistent with proposed “rotamer switch” models. Interestingly, no comparable cation–π interaction was found at the aligning residue in the M2 receptor
The Utility of Trouble: Maximizing the Value of Our Human Services Dollars
Outlines recommendations to standardize service delivery areas and consolidate area offices of the state's seven largest human services agencies, as well as to close antiquated institutions. Projects benefits such as improved accessibility and savings
Dendritic side-branching with anisotropic viscous fingering
We studied dendritic side-branching mechanism in the experiment of
anisotropic viscous fingering. We measured the time dependence of growth speed
of side-branch and the envelop of side-branches. We found that the speed of
side-branch gets to be faster than one of the stem and the growth exponent of
the speed changes at a certain time. The envelope of side-branches is
represented as Y ~ X^1.47.Comment: 8 pages, 8 figures, to submited in J. Crystal Growt
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