THE RELATIONSHIP among cardiac pacemakers is characterized by the fact that usually one pacemaker is dominant and all the others are subsidiary. The sinoatrial node acts as the dominant pacemaker and all other pacemaker tissues are discharged by a conducted impulse before their diastolic depolarization can attain threshold. These pacemakers are called subsidiary to emphasize the fact that under...

Iso-orientation surround suppression is a powerful form of visual contextual modulation in which a stimulus of the preferred orientation of a neuron placed outside the classical receptive field (CRF) of the neuron suppresses the response to stimuli within the CRF. This suppression is most often attributed to orientation-tuned signals that propagate laterally across the cortex, activating local ...

a 64-year-old male presented with neurofibromatosis 1 and cushing’s syndrome. clinically he was over weight, depressed with extensive skin bruising and hypertension. his 24 hours urinary metanephrines, urinary 5hiaa, gut peptides and chromgranin levels were normal. his renal function and renal mri scan was also normal. his cortisol failed to suppress on overnight dexamethsone suppression test. ...

The tumor suppressor gene TP53 and its gene product—a veritable swiss Army knife of cellular regulation—have been the targets of intense study since their discovery in 1979. 1-3 indeed, a PubMed search for the term " p53 " retrieves more than 68 000 citations, and more than 100 physical or genetic interactions with TP53 have been identified to date. its importance in cancer biology was recogniz...

always to give rigorous quantitative expression to qualitative concepts. This was encapsulated in his famous review in 1948 of the properties of haem proteins. A notable paper by Wyman and D.W. Allen in 1951 could be said to prefigure what later became known as the allosteric hypothesis. After his return to (more or less) full-time science Wyman developed the theoretical basis of the scheme of ...

In this paper, we propose a novel acoustic echo suppression (AES) technique based on soft decision in a frequency domain. The proposed approach provides an ef cient and uni ed framework for such procedures as AES gain computation, AES gain modi cation using soft decision, and estimation of relevant parameters based on the same statistical model assumption of the near-end and far-end signal inst...

Genetic suppression has provided a very powerful tool for analyzing C. elegans. Suppression experiments are facilitated by the ability to handle very large numbers of individuals and to apply powerful selections. Because the animal grows as a self-fertilizing diploid, both dominant and recessive suppressors can be recovered. Many different kinds of suppression have been reported. These are disc...

Background: Several studies have demonstrated the immunosuppresive effects of mes-enchymal stem cells (MSCs) in allogeneic or mitogenic interactions. Cell-cell contact inhibition and secretion of suppressive soluble factors have been suggested in this re-gard. Objective: To investigate if adipose derived MSCs could inhibit Jurkat lym-phoblastic leukemia T cell proliferation during coculture. Me...