A Model of a MAPK•Substrate Complex in an Active Conformation: A Computational and Experimental Approach

The mechanisms by which MAP kinases recognize and phosphorylate substrates are not completely understood. Efforts to understand the mechanisms have been compromised by the lack of MAPK-substrate structures. While MAPK-substrate docking is well established as a viable mechanism for bringing MAPKs and substrates into close proximity the molecular details of how such docking promotes phosphorylation is an unresolved issue. In the present study computer modeling approaches, with restraints derived from experimentally known interactions, were used to predict how the N-terminus of Ets-1 associates with ERK2. Interestingly, the N-terminus does not contain a consensus-docking site ((R/K)2-3-X2-6-ΦA-X-ΦB, where Φ is aliphatic hydrophobic) for ERK2. The modeling predicts that the N-terminus of Ets-1 makes important contributions to the stabilization of the complex, but remains largely disordered. The computer-generated model was used to guide mutagenesis experiments, which support the notion that Leu-11 and possibly Ile-13 and Ile-14 of Ets-1 1-138 (Ets) make contributions through binding to the hydrophobic groove of the ERK2 D-recruiting site (DRS). Based on the modeling, a consensus-docking site was introduced through the introduction of an arginine at residue 7, to give the consensus 7RK-X2-ΦA-X-ΦB13. This results in a 2-fold increase in kcat/Km for the phosphorylation of Ets by ERK2. Similarly, the substitution of the N-terminus for two different consensus docking sites derived from Elk-1 and MKK1 also improves kcat/Km by two-fold compared to Ets. Disruption of the N-terminal docking through deletion of residues 1-23 of Ets results in a 14-fold decrease in kcat/Km, with little apparent change in kcat. A peptide that binds to the DRS of ERK2 affects Km, but not kcat. Our kinetic analysis suggests that the unstructured N-terminus provides 10-fold uniform stabilization of the ground state ERK2•Ets•MgATP complex and intermediates of the enzymatic reaction

Chinese organized crime and situational context: comparing human smuggling and synthetic drugs trafficking

This article criticizes the 'ethnic' conception of organized crime and puts forward an alternative view that does not put ethnicity first, but rather social networks and situational context. It focuses upon Chinese organized crime, a phenomenon where the preoccupation with ethnicity is paramount, and compares findings from extensive research into two different transnational criminal activities that are carried out by Chinese offenders in the Netherlands. The first topic, human smuggling, is well researched, whereas research into the second topic, trafficking in precursors (the basic ingredients for the production of synthetic drugs), is largely lacking. The article highlights the major theoretical and empirical similarities and differences between these two criminal activities and discusses the relevance of the main findings for theory and research

International Society of Sports Nutrition Position Stand: Probiotics.

Position statement: The International Society of Sports Nutrition (ISSN) provides an objective and critical review of the mechanisms and use of probiotic supplementation to optimize the health, performance, and recovery of athletes. Based on the current available literature, the conclusions of the ISSN are as follows: 1)Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host (FAO/WHO).2)Probiotic administration has been linked to a multitude of health benefits, with gut and immune health being the most researched applications.3)Despite the existence of shared, core mechanisms for probiotic function, health benefits of probiotics are strain- and dose-dependent.4)Athletes have varying gut microbiota compositions that appear to reflect the activity level of the host in comparison to sedentary people, with the differences linked primarily to the volume of exercise and amount of protein consumption. Whether differences in gut microbiota composition affect probiotic efficacy is unknown.5)The main function of the gut is to digest food and absorb nutrients. In athletic populations, certain probiotics strains can increase absorption of key nutrients such as amino acids from protein, and affect the pharmacology and physiological properties of multiple food components.6)Immune depression in athletes worsens with excessive training load, psychological stress, disturbed sleep, and environmental extremes, all of which can contribute to an increased risk of respiratory tract infections. In certain situations, including exposure to crowds, foreign travel and poor hygiene at home, and training or competition venues, athletes' exposure to pathogens may be elevated leading to increased rates of infections. Approximately 70% of the immune system is located in the gut and probiotic supplementation has been shown to promote a healthy immune response. In an athletic population, specific probiotic strains can reduce the number of episodes, severity and duration of upper respiratory tract infections.7)Intense, prolonged exercise, especially in the heat, has been shown to increase gut permeability which potentially can result in systemic toxemia. Specific probiotic strains can improve the integrity of the gut-barrier function in athletes.8)Administration of selected anti-inflammatory probiotic strains have been linked to improved recovery from muscle-damaging exercise.9)The minimal effective dose and method of administration (potency per serving, single vs. split dose, delivery form) of a specific probiotic strain depends on validation studies for this particular strain. Products that contain probiotics must include the genus, species, and strain of each live microorganism on its label as well as the total estimated quantity of each probiotic strain at the end of the product's shelf life, as measured by colony forming units (CFU) or live cells.10)Preclinical and early human research has shown potential probiotic benefits relevant to an athletic population that include improved body composition and lean body mass, normalizing age-related declines in testosterone levels, reductions in cortisol levels indicating improved responses to a physical or mental stressor, reduction of exercise-induced lactate, and increased neurotransmitter synthesis, cognition and mood. However, these potential benefits require validation in more rigorous human studies and in an athletic population

Patriarch luo as a writer and reader: Speculating about the creative process behind the Five books in six volumes

Patriarch Luo or Luo Qing was the author of a very influential religious work traditionally known as the Five Books in Six Volumes. They contain his religious autobiography as well as statements on various points of religious practice, supported by a wealth of quotations that stem mostly from the Buddhist canon. This article first deals briefly with Luo Qing's biography, pointing out that reliable historical knowledge on him is extremely limited. Much of what is claimed about him in the secondary literature, including his purported name of Luo Menghong, is derived from later, mythological sources. What we do have are his own written works. By analyzing patterns in quotations from these works, this article tries to uncover the author's patterns of reading and writing. A quantitative analysis of the sources shows that the Five Books in Six Volumes seemingly quote a large number of different, mostly Buddhist texts, but that by far the largest number of these quotations comes from a very small number of works. Moreover, the quotations often have minor mistakes, appear in the wrong sequence, and are highly selective and even haphazard. On the basis of an analysis of some striking examples, it is argued that Patriarch Luo or Luo Qing may not even have been quoting directly from written texts, but was instead quoting from memory. This would also explain why he sometimes quotes only a very small number of fragments from one particular source, since he may not been quoting directly from that source, but rather from a lecture he heard from a Buddhist teacher at one or another point in his life

Warping a Neuro-Anatomy Atlas on 3D MRI Data with Radial Basis Functions

Navigation for neurosurgical procedures must be highly accurate. Often small structures are hardly seen on pre-operative scans. Fitting a 3D electronic neuro-anatomical atlas on the data assists with the localization of small structures and dim outlines. During surgery also brainshifts occurs. With intra-operative MRI the pre-operative MRI can be warped to the real 3D situation. The paper describes a general 3D landmark-based warping method, based on radial basis functions (thin plate splines) for data of any number of dimensions, including all code in Mathematica

Optic flow based on multi-scale anchor point movement and discontinuity-preserving regularization

We introduce a new method to determine the flow field of an image sequence using multi-scale anchor points. These anchor points manifest themselves in the scale-space representation of an image. The novelty of our method lies largely in the fact that the relation between the scale-space anchor points and the flow field is formulated in terms of soft constraints in a variational method. This leads to an algorithm for the computation of the flow field that differs fundamentally from previously proposed ones based on hard constraints. We show a significant performance increase when our method is applied to the Yosemite image sequence, a standard and well-established benchmark sequence in optic flow research. Also, it is shown that this performance is not sensitive to slight changes in the two parameters used and that, with the same parameter values, our method yields very good results in the Rubber Whale image sequence as well

A linear image reconstruction framework based on Sobolev type inner products

Exploration of information content of features that are present in images has led to the development of several reconstruction algorithms. These algorithms aim for a reconstruction from the features that is visually close to the image from which the features are extracted. Degrees of freedom that are not fixed by the constraints are disambiguated with the help of a so-called prior (i.e. a user defined model). We propose a linear reconstruction framework that generalizes a previously proposed scheme. The algorithm greatly reduces the complexity of the reconstruction process compared to non-linear methods. As an example we propose a specific prior and apply it to the reconstruction from singular points. The reconstruction is visually more attractive and has a smaller L2-error than the reconstructions obtained by previously proposed linear methods