Oscillating latent dynamics in robot systems during walking and reaching.

Sensorimotor control of complex, dynamic systems such as humanoids or quadrupedal robots is notoriously difficult. While artificial systems traditionally employ hierarchical optimisation approaches or black-box policies, recent results in systems neuroscience suggest that complex behaviours such as locomotion and reaching are correlated with limit cycles in the primate motor cortex. A recent result suggests that, when applied to a learned latent space, oscillating patterns of activation can be used to control locomotion in a physical robot.

Third ventricular width assessed by transcranial ultrasound correlates with cognitive performance in Parkinson's disease.

Introduction: Cognitive impairment and dementia are common in PD; however, no stable marker of cognitive dysfunction is available. Transcranial sonography can evaluate global and focal brain atrophy and has been widely used in the differential diagnosis of parkinsonism.

Methods: 225 consecutive PD patients were recruited in a two-center cross sectional study and underwent a standardized sonographic protocol assessing the third ventricle's width and substantia nigra hyperechogenicity.

Do You See It My Way? The Clinical Evaluation of ADHD by the Different Pediatric Subspecialties.

Background: Six medical disciplines are responsible for assessment, diagnosis and treatment of people with attention deficiency hyperactivity disorder (ADHD) in Israel: family doctors, pediatricians, adult and child neurologists, adult and child psychiatrists.

Objectives: To investigate differences in ADHD diagnostic practices between three different pediatric subspecialties in the clinical setting in order to establish a common ground for a future unified approach.

Methods: An anonymous web-based questionnaire was administered to child psychiatrists, pediatric neurologists and general pediatricians who are actively involved in ADHD diagnosis (n=104).

Kinetics of phosphorylation of the SH2-containing domain of phospholipase C gamma 1 by the epidermal growth factor receptor.

The kinetics of the EGF receptor (EGFR) autophosphorylation and of the phosphorylation by EGFR of a fusion protein (Fp(SH2)) derived from PLC-gamma 1 with two SH2 domains were studied employing purified EGFR or membrane-bound preparations of native and truncated EGFR. With varied ATP concentrations both reactions yielded Michaelis-Menten kinetics. KATP for autophosphorylation was 0.

Kinetics of inhibition by tyrphostins of the tyrosine kinase activity of the epidermal growth factor receptor and analysis by a new computer program.

The kinetics of inhibition of the epidermal growth factor (EGF) receptor (EGFR) tyrosine kinase (TK) activity by erbstatin, tyrphostins, and lavendustin derivatives were studied in a system that employs poly(Glu6Ala3Tyr) (GAT) and ATP as substrates, after preactivation with EGF. All data were analyzed for computer best-fit curves by a program that was written for this purpose and is available upon request to those interested. The inhibition kinetics followed a sequential, Bi-Bi, rapid equilibrium, random mechanism, the mechanism of the EGFR-TK.

Tyrphostins. 3. Structure-activity relationship studies of alpha-substituted benzylidenemalononitrile 5-S-aryltyrphostins.

In this study we describe an extension of our previous studies on cis-benzylidenemalononitrile tyrphostins. We have introduced S-aryl substituents in the 5 position (meta vis-a-vis the malononitrile moiety). We find that these compounds are potent blockers of EGFR kinase and its homolog HER-2 kinase.

Tyrphostins inhibit follicle-stimulating hormone-mediated functions in cultured rat ovarian granulosa cells.

FSH induces the expression of cholesterol side-chain cleavage cytochrome P450 (P450scc) in rat ovarian granulosa cells. The present study reveals that the tyrphostin AG18, a member of novel protein tyrosine kinase inhibitors, can arrest the FSH-induced synthesis of P450scc with an apparent IC50 of 30 microM. Total inhibition of P450scc expression was achieved at 80 microM AG18.

Kinetic model of the epidermal growth factor (EGF) receptor tyrosine kinase and a possible mechanism of its activation by EGF.

The tyrosine kinase activity of the epidermal growth factor receptor (EGFR-TK) was determined at varying poly-Glu6Ala3Tyr1 (GAT) or [Val5]-angiotensin II (AT) and constant ATP concentrations and vice versa. With GAT as substrate, double reciprocal plots intersected practically on the abscissa following EGFR-TK pre-activation with EGF, but below the abscissa without EGF pre-activation. The EGFR-TK inhibitors App(NH)p (5'-adenylyl-beta, gamma-imidodiphosphate) and ADP were competitive with ATP and noncompetitive with GAT.

Tyrphostins. 2. Heterocyclic and alpha-substituted benzylidenemalononitrile tyrphostins as potent inhibitors of EGF receptor and ErbB2/neu tyrosine kinases.

We have previously described a novel series of low molecular weight protein tyrosine kinase inhibitors which we named tyrphostins. The characteristic active pharmacophore of these compounds was the hydroxy-cis-benzylidenemalononitrile moiety. In this article we describe three novel groups of tyrphostins: (i) one group has the phenolic moiety of the cis-benzylidenemalononitrile replaced either with other substituted benzenes or with heteroaromatic rings, (ii) another is a series of conformationally constrained derivatives of hydroxy-cis-benzylidenemalononitriles in which the malononitrile moiety is fixed relative to the aromatic ring, and (iii) two groups of compounds in which the position trans to the benzenemalononitrile has been substituted by ketones and amides.

No severe bottleneck during human evolution: evidence from two apolipoprotein C-II deficiency alleles.

The DNA sequences of a Japanese and a Venezuelan apolipoprotein (apo) C-II deficiency allele, of a normal Japanese apo C-II gene, and of a chimpanzee apo C-II gene were amplified by PCR, and their nucleotide sequences were determined on multiple clones of the PCR products. The normal Japanese sequence is identical to--and the chimpanzee sequence differs by only three nucleotides from--a previously published normal Caucasian sequence. In contrast, the two human mutant sequences each differ from the normal apo C-II gene sequence by several nucleotides, including deletions.

Tyrphostins inhibit the epidermal growth factor receptor-mediated breakdown of phosphoinositides.

In response to epidermal growth factor (EGF) and the Ca2+ ionophore A23187, the total phosphatidylinositides (IPT) increased in A431 human epidermoid carcinoma cells 1.8- and 2.0-fold and in the EGF-dependent A431/Clone 15-2 cells 3.

Kinetics of product inhibition and mechanisms of lipoprotein lipase activation by apolipoprotein C-II.

The kinetics of product inhibition of bovine milk lipoprotein lipase (LPL) were studied in a system of emulsified trioleoylglycerol (TG) at different fixed initial concentrations of oleic acid [( OA]0) without a fatty acid (FA) acceptor. In the absence of apolipoprotein C-II (C-II), the apparent Vmax and the nH(TG) (the slope of the corresponding Hill plot for TG) of 1.82 decreased by about 52% and [TG]0.

The kinetics of heparin inhibition of the esterase and basal lipase activities of lipoprotein lipase.

The kinetics of inhibition of the esterase and lipase activities of bovine milk lipoprotein lipase (LPL) were compared. The esterase LPL activity against emulsified tributyrylglycerol was not affected by the enzyme activator apolipoprotein C-II (C-II) and amounted to about 15% of the "plus activator" lipase enzyme activity. Heparin at concentrations of 20 micrograms/ml inhibited 25% of the esterase activity.

Variation of lumbar spine stiffness with load.

Mechanical studies of the Functional Spinal Unit (FSU) in-vitro have shown that the slopes of the load-displacement curves increase with load. This nonlinearity implies that the stiffness of the FSU is not constant over the range of physiologic loads, and that measurements obtained for FSU specimens through the application of individual loads cannot be summed to predict the response of the specimens to combined loads. Both experimental and analytical methods were developed in the present study to better quantify the nonlinear FSU load-displacement response and to calculate the coupled stiffness of FSU specimens at combined states of load reflecting in-vivo conditions.

The effects of bovine serum albumin and oleic acid on rat pancreatic lipase and bovine milk lipoprotein lipase.

The effects of bovine serum albumin on rat pancreatic lipase and bovine milk lipoprotein lipase were studied in a system of triacylglycerol emulsions stabilized by 1 1 mg/ml albumin. At concentrations greater than 1 mg/ml, albumin inhibited the activity of pancreatic lipase and interfered with enzyme binding to emulsified triacylglycerol particles. These effects could be countered by occupying five fatty acid binding sites on albumin with oleic acid.

Kinetics of human and bovine milk lipoprotein lipase and the mechanism of enzyme activation by apolipoprotein C-II.

The kinetics of human and bovine milk lipoprotein lipase (HM-LPL and BM-LPL, respectively) were compared by varying apolipoprotein C-II (C-II) or triacylglycerol (TG) concentrations. The apparent Km (TG) and Km (C-II) for HM-LPL were 2.2 and 6.