2,675 research outputs found
Ergopeptine-Sensitive Calcium-Dependent Protein Phosphorylation System in the Brain
We studied a protein phosphorylation system that is regulated by the dopamine-mimetic ergot bromocriptine. Bromocriptine was found to inhibit selectively the endogenous phosphorylation of a threonine residue(s) in 50,000- and 60,000-dalton proteins in a synaptosome fraction. The bromocriptine-sensitive phosphorylation is stimulated by calcium and by calmodulin, and occurs predominantly in the brain. The inhibitory effect of bromocriptine was not mimicked by 3,4-dihydroxyphenylethylamine or by any of the neurotransmitters and related agents tested, but was mimicked, although less effectively, by other ergots that contain peptide moieties. In the hippocampus, the brain region with the highest content of the 50,000- and 60,000-dalton proteins, the ergopeptine-sensitive protein phosphorylation appears to be localized to interneurons or cell bodies whose axons synapse outside the hippocampus. The results raise the possibility that some of the bromocriptine- and ergopeptine-induced pharmacological effects in the CNS may be mediated by the inhibition of the calcium/calmodulin-dependent phosphorylation of these specific proteins.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65208/1/j.1471-4159.1984.tb02758.x.pd
Investigating the sources of variability in the dynamic response of built-up structures through a linear analytical model
It is well established that the dynamic response of a number of nominally identical builtup
structures are often different and the variability increases with increasing complexity
of the structure. Furthermore, the effects of the different parameters, for example the
variation in joint locations or the range of the Young's modulus, on the dynamic response
of the system are not the same. In this paper, the effects of different material and geometric
parameters on the variability of a vibration transfer function are compared using
an analytical model of a simple linear built-up structure that consist of two plates connected
by a single mount. Similar results can be obtained if multiple mounts are used. The
scope of this paper is limited to a low and medium frequency range where usually deterministic
models are used for vibrational analysis.
The effect of the mount position and also the global variation in the properties of the
plate, such as modulus of elasticity or thickness, is higher on the variability of vibration
transfer function than the effect of the mount properties. It is shown that the vibration
transfer function between the plates is independent of the mount property if a stiff enough
mount with a small mass is implemented. For a soft mount, there is a direct relationship
between the mount impedance and the variation in the vibration transfer
function. Furthermore, there are a range of mount stiffnesses between these two extreme
cases at which the vibration transfer function is more sensitive to changes in the stiffness
of the mount than when compared to a soft mount. It is found that the effect of variation
in the mount damping and the mount mass on the variability is negligible. Similarly, the
effect of the plate damping on the variability is not significant
Structure of a gene encoding a murine thymus leukemia antigen, and organization of Tla genes in the BALB/c mouse
We have determined the DNA sequence of a gene encoding a thymus leukemia (TL) antigen in the BALB/c mouse, and have more definitively mapped the cloned BALB/c Tla-region class I gene clusters. Analysis of the sequence shows that the Tla gene is less closely related to the H-2 genes than H-2 genes are to one another or to a Qa-2,3-region genes. The Tla gene, 17.3A, contains an apparent gene conversion. Comparison of the BALB/c Tla genes with those from C57BL shows that BALB/c has more Tla-region class I genes, and that one of the genes absent in C57BL is gene 17.3A
Investigating the sources of variability in the dynamic response of built-up structures through a linear analytical model
It is well established that the dynamic response of a number of nominally identical builtup
structures are often different and the variability increases with increasing complexity
of the structure. Furthermore, the effects of the different parameters, for example the
variation in joint locations or the range of the Young's modulus, on the dynamic response
of the system are not the same. In this paper, the effects of different material and geometric
parameters on the variability of a vibration transfer function are compared using
an analytical model of a simple linear built-up structure that consist of two plates connected
by a single mount. Similar results can be obtained if multiple mounts are used. The
scope of this paper is limited to a low and medium frequency range where usually deterministic
models are used for vibrational analysis.
The effect of the mount position and also the global variation in the properties of the
plate, such as modulus of elasticity or thickness, is higher on the variability of vibration
transfer function than the effect of the mount properties. It is shown that the vibration
transfer function between the plates is independent of the mount property if a stiff enough
mount with a small mass is implemented. For a soft mount, there is a direct relationship
between the mount impedance and the variation in the vibration transfer
function. Furthermore, there are a range of mount stiffnesses between these two extreme
cases at which the vibration transfer function is more sensitive to changes in the stiffness
of the mount than when compared to a soft mount. It is found that the effect of variation
in the mount damping and the mount mass on the variability is negligible. Similarly, the
effect of the plate damping on the variability is not significant
An Inversion Method for Measuring Beta in Large Redshift Surveys
A precision method for determining the value of Beta= Omega_m^{0.6}/b, where
b is the galaxy bias parameter, is presented. In contrast to other existing
techniques that focus on estimating this quantity by measuring distortions in
the redshift space galaxy-galaxy correlation function or power spectrum, this
method removes the distortions by reconstructing the real space density field
and determining the value of Beta that results in a symmetric signal. To remove
the distortions, the method modifies the amplitudes of a Fourier plane-wave
expansion of the survey data parameterized by Beta. This technique is not
dependent on the small-angle/plane-parallel approximation and can make full use
of large redshift survey data. It has been tested using simulations with four
different cosmologies and returns the value of Beta to +/- 0.031, over a factor
of two improvement over existing techniques.Comment: 16 pages including 6 figures Submitted to The Astrophysical Journa
Legalizing Merger to Monopoly and Higher Prices: The Canadian Competition Tribunal Gets It Wrong
This article analyzes the Canadian Superior Propane decision, apparently the first merger decision in world history to consider explicitly what to do when a merger was predicted to lead to both higher consumer prices and to net efficiencies. The article advocates analyzing the merger under a price to consumers or consumer welfare standard, rather than a total efficiency standard, and advocates that the enforcers and the courts block such mergers
Norton Healthcare: A Strong Payer-Provider Partnership for the Journey to Accountable Care
Examines the progress of an integrated healthcare delivery system in forming an accountable care organization with payer partners as part of the Brookings-Dartmouth ACO Pilot Program, including a focus on performance measurement and reporting
Invisible water, visible impact: How unsustainable groundwater use challenges sustainability of Indian agriculture under climate change
India is one of the world’s largest food producers, making the sustainability of its agricultural system of global significance. Groundwater irrigation underpins India’s agriculture, currently boosting crop production by enough to feed 170 million people. Groundwater overexploitation has led to drastic declines in groundwater levels, threatening to push this vital resource out of reach for millions of small-scale farmers who are the backbone of India’s food security. Historically, losing access to groundwater has decreased agricultural production and increased poverty. We take a multidisciplinary approach to assess climate change challenges facing India’s agricultural system, and to assess the effectiveness of large-scale water infrastructure projects designed to meet these challenges. We find that even in areas that experience climate change induced precipitation increases, expansion of irrigated agriculture will require increasing amounts of unsustainable groundwater. The large proposed national river linking project has limited capacity to alleviate groundwater stress. Thus, without intervention, poverty and food insecurity in rural India is likely to worsen
Selection Tool Use: A Focus on Personality Testing in Canada, the United States, and Germany
The purpose of this paper is to provide new data regarding the current staffing practices being used by organizations in Canada and the United States (US) as well as a comparison with existing data from Germany (Diekmann & König, 2015). Data regarding the beliefs of human resource (HR) practitioners in terms of using personality tests in personnel selection is also provided. A geographically representative sample of 453 HR practitioners across Canada and the US were surveyed. Although general mental ability testing has previously been found to be highly valid and cost effective, this selection tool was among the least commonly used in all three countries. Personality tests were also rarely used (especially in Canada and the US) and research–practice gaps still appear to be an issue (e.g., HR practitioners’ preference for personality types as opposed to traits)
The uncertainty in stiffness and damping of an automotive vehicle's trim-structure mounts and its effect on the variability of the vibration transfer function
A large number of plastic clips are used in an automotive vehicle to connect the trim to the structure. These are small clips with very small masses compared to the structural elements that they connect together; however, the uncertainty in their properties can affect the dynamic response. The uncertainty arises out of their material and manufacturing tolerances and more importantly the boundary conditions. A test rig has been developed that can model the mounting condition of the clips. This allows measurement of the range of their effective stiffness and damping. Initially, the boundary condition at the structure side is replicated. The variability is found to be 7% for stiffness and 8% for damping. In order to simulate the connection of the trim side, a mount is built using a 3D printer. The variability due to the boundary condition on both sides was as large as 40% for stiffness and 36% for damping. A Monte Carlo simulation is used in order to assess the effect of the uncertainty of the clips’ properties on the vibration transfer functions of a door assembly. A simplified connection model is used in this study where only the axial degree of freedom is considered in connecting the trim to the door structure. The uncertainty in the clip stiffness and damping results in a variability in the vibration transfer function which is frequency dependent and can be as high as 10% at the resonant peaks with higher values at some other frequencies. It is shown that the effect of the uncertainty in the clips effective damping is negligible and the variability in the dynamic response is mainly due to the uncertainty in the clip’s stiffness. Furthermore, it is shown that the variability would reduce either by increasing or decreasing the effective stiffness of the clips
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