20,293 research outputs found
Kinetics and Inhibition Studies of the L205R Mutant of cAMP-Dependent Protein Kinase Involved in Cushingās Syndrome
Overproduction of cortisol by the hypothalamusāpituitaryāadrenal hormone system results in the clinical disorder known as Cushing\u27s syndrome. Genomics studies have identified a key mutation (L205R) in the Ī±āisoform of the catalytic subunit of cAMPādependent protein kinase (PKACĪ±) in adrenal adenomas of patients with adrenocorticotropic hormoneāindependent Cushing\u27s syndrome. Here, we conducted kinetics and inhibition studies on the L205RāPKACĪ± mutant. We have found that the L205R mutation affects the kinetics of both Kemptide and ATP as substrates, decreasing the catalytic efficiency (kcat/KM) for each substrate by 12āfold and 4.5āfold, respectively. We have also determined the IC50 and Ki for the peptide substrateācompetitive inhibitor PKI(5ā24) and the ATPācompetitive inhibitor H89. The L205R mutation had no effect on the potency of H89, but causes a \u3e 250āfold loss in potency for PKI(5ā24). Collectively, these data provide insights for the development of L205RāPKACĪ± inhibitors as potential therapeutics
LoCoH: nonparameteric kernel methods for constructing home ranges and utilization distributions.
Parametric kernel methods currently dominate the literature regarding the construction of animal home ranges (HRs) and utilization distributions (UDs). These methods frequently fail to capture the kinds of hard boundaries common to many natural systems. Recently a local convex hull (LoCoH) nonparametric kernel method, which generalizes the minimum convex polygon (MCP) method, was shown to be more appropriate than parametric kernel methods for constructing HRs and UDs, because of its ability to identify hard boundaries (e.g., rivers, cliff edges) and convergence to the true distribution as sample size increases. Here we extend the LoCoH in two ways: "fixed sphere-of-influence," or r-LoCoH (kernels constructed from all points within a fixed radius r of each reference point), and an "adaptive sphere-of-influence," or a-LoCoH (kernels constructed from all points within a radius a such that the distances of all points within the radius to the reference point sum to a value less than or equal to a), and compare them to the original "fixed-number-of-points," or k-LoCoH (all kernels constructed from k-1 nearest neighbors of root points). We also compare these nonparametric LoCoH to parametric kernel methods using manufactured data and data collected from GPS collars on African buffalo in the Kruger National Park, South Africa. Our results demonstrate that LoCoH methods are superior to parametric kernel methods in estimating areas used by animals, excluding unused areas (holes) and, generally, in constructing UDs and HRs arising from the movement of animals influenced by hard boundaries and irregular structures (e.g., rocky outcrops). We also demonstrate that a-LoCoH is generally superior to k- and r-LoCoH (with software for all three methods available at http://locoh.cnr.berkeley.edu)
Phase Transitions on Nonamenable Graphs
We survey known results about phase transitions in various models of
statistical physics when the underlying space is a nonamenable graph. Most
attention is devoted to transitive graphs and trees
Legal Authority and Limitations
The core element for emergency involuntary commitment is dangerousness to oneself or others. Statutes typically also mandate immediate or near immediate petition to the courts, and require immediate or near immediate professional psychiatric review. This chapter reviews the case law associated with civil commitment statutes, both historically and in terms of current issues
Predictors of Juvenile Court Dispositions in a First-Time Offender Population
Scholars and policy makers have long been troubled by the potential for some youth to receive disparate sanctioning as a function of extralegal factors, especially against the backdrop of ethnic/racial minority group overrepresentation in the juvenile justice system as a whole. Beginning in the late 1990s, many states began to adopt a graduated sanctions model in response to the emerging āget toughā zeitgeist of the day. Originally intended by the federal government to reinforce juvenile accountability and to ensure equitable treatment of all youth in custody, some stakeholders began to note concerns about uneven outcomes in the use of graduated sanctioning schemes. Specifically, data across multiple jurisdictions suggested that racial and ethnic minority youth were receiving more restrictive than expected sanctions. The current study in one large urban jurisdiction explored this issue in a group of 2,786 racially and ethnically diverse first-time juvenile male offenders (ages 10-17). Results indicated that race/ethnicity was not a predictor of receiving a more restrictive than expected sanction; however, variables related to offending (offense severity, history of violence), age (older), and parental supervision (inadequate) were significant predictors of such departures
Ethical Issues in Conducting Forensic Evaluations
The role of the forensic mental health professional (MHP) often differs substantially from that of the typical clinician. These differences bear directly on the ethical delivery of services
Scattering statistics of rock outcrops: Model-data comparisons and Bayesian inference using mixture distributions
The probability density function of the acoustic field amplitude scattered by
the seafloor was measured in a rocky environment off the coast of Norway using
a synthetic aperture sonar system, and is reported here in terms of the
probability of false alarm. Interpretation of the measurements focused on
finding appropriate class of statistical models (single versus two-component
mixture models), and on appropriate models within these two classes. It was
found that two-component mixture models performed better than single models.
The two mixture models that performed the best (and had a basis in the physics
of scattering) were a mixture between two K distributions, and a mixture
between a Rayleigh and generalized Pareto distribution. Bayes' theorem was used
to estimate the probability density function of the mixture model parameters.
It was found that the K-K mixture exhibits significant correlation between its
parameters. The mixture between the Rayleigh and generalized Pareto
distributions also had significant parameter correlation, but also contained
multiple modes. We conclude that the mixture between two K distributions is the
most applicable to this dataset.Comment: 15 pages, 7 figures, Accepted to the Journal of the Acoustical
Society of Americ
Spasmodic dysphonia may respond to bilateral thalamic deep brain stimulation
Background Spasmodic dysphonia is a primary focal dystonia manifested by loss of control of the vocal muscles during speech secondary to laryngeal muscle spasms. The pathophysiology is not well understood. Deep brain stimulation surgery (DBS) for other focal dystonias has been well reported. Methods We report the first case of bilateral thalamic DBS improving spasmodic dystonia (SD) in a patient with essential tremor.Results This case demonstrates the beneficial of effects of bilateral thalamic DBS for both ET of the hands and AdSD of the vocal cords.Conclusions The potential pathophysiologic mechanisms of this finding are discussed
Load Sharing in Gravel Decked Log Stringer Bridges
Log bridges are an economical alternative to steel and concrete structures for temporary crossings; however, reduced availability of large logs for stringers and the advancing age of existing log bridges increases the importance of structural analysis. Load sharing between the stringers is complicated and can result from load spread due to the gravel deck, cable lashing, and mechanical interlocking and friction between the stringers. This paper describes the development of a finite element model (FEM) for gravel decked log stringer bridges that includes elements capable of transferring vertical loads between the stringers. The FEM was used to interpret load deflection data from two in-situ bridges. The results of this paper suggest the segments of lashing that pass under one stringer and over an adjacent stringer contribute to load sharing between the stringers; however, care must be taken to ensure that the pattern of lashing supports the stringers directly loaded by the live loads
Determining the impacts of climate change on iconic trees, woodlands and forest ecosystems in Western Australia
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