Quantum MIMO n-Systems and Conditions for Stability

In this paper we present some conditions for the (strong) stabilizability of an n-D Quantum MIMO system P(X). It contains two parts. The first part is to introduce the n-D Quantum MIMO systems where the coefficients vary in the algebra of Q-meromorphic functions. Then we introduce some conditions for the stabilizability of these systems. The second part is to show that this Quantum system has the n-D system as its quantum limit and the results for the SISO,SIMO,MISO,MIMO are obtained again as special cases.Comment: 6 page

Investigating the physiological role of PYY-expressing cells in the gut and pancreas

Peptide YY (PYY) is a hormone produced by the enteroendocrine L cells in the gut. It is also expressed in the pancreatic islets and brainstem. PYY is secreted from the L cells in proportion to caloric intake and is involved in the regulation of satiety and energy homeostasis. The physiological role of PYY in the pancreatic islets and brainstem is not clear. In order to investigate the physiological role of PYY-expressing cells, I used a transgenic mouse model in which diphtheria toxin receptor (DTR) is expressed downstream of the PYY promoter. This enabled ablation of the PYY-expressing cells following administration of diphtheria toxin (DT) in adult mice. Intraperitoneal administration of DT at a dose of 40ng/g resulted in a significant loss of colonic, pancreatic and brainstem PYY (> 95%). Interestingly, ablation of PYY-expressing cells resulted in a significant loss of pancreatic insulin and hence severe hyperglycaemia in adult mice. In vitro administration of DT in cultured islets resulted in a significant dose-dependent loss of insulin, PYY and glucagon content. Immunohistochemical distribution of DTR was shown to be limited to the periphery of the islet, where PYY is also expressed. These experiments suggest that a product of the PYY-expressing cells may provide a paracrine factor essential for beta cell viability. Replacement of PYY using twice-daily subcutaneous injection of a long-acting PYY analogue (X-PYY) prevented the development of diabetes and reduced the loss of pancreatic insulin content. Administration of the analogue also reduced insulin loss in streptozotocin-treated mice. These studies suggest that PYY may be an important signal for beta cell maintenance. These findings have important implications for identifying novel therapies for prevention of beta cell loss in diabetes mellitus

Sheaf Theory as a Foundation for Heterogeneous Data Fusion

A major impediment to scientific progress in many fields is the inability to make sense of the huge amounts of data that have been collected via experiment or computer simulation. This dissertation provides tools to visualize, represent, and analyze the collection of sensors and data all at once in a single combinatorial geometric object. Encoding and translating heterogeneous data into common language are modeled by supporting objects. In this methodology, the behavior of the system based on the detection of noise in the system, possible failure in data exchange and recognition of the redundant or complimentary sensors are studied via some related geometric objects. Applications of the constructed methodology are described by two case studies: one from wildfire threat monitoring and the other from air traffic monitoring. Both cases are distributed (spatial and temporal) information systems. The systems deal with temporal and spatial fusion of heterogeneous data obtained from multiple sources, where the schema, availability and quality vary. The behavior of both systems is explained thoroughly in terms of the detection of the failure in the systems and the recognition of the redundant and complimentary sensors. A comparison between the methodology in this dissertation and the alternative methods is described to further verify the validity of the sheaf theory method. It is seen that the method has less computational complexity in both space and time

Reply to racial and gender disparities among patients with Takotsubo syndrome

We read with great interest the Letter to the Editor titled “Racial and Gender Disparities among Patients with Takotsubo Syndrome” by Khalid et al regarding our recent publication. Their excellent comments and detailed assessment highlights the low prevalence of diabetes mellitus in patients with Takotsubo syndrome (TTS) compared to general population. This is in contrast with relatively high prevalence of many other cardiovascular risk factors in TTS patients. This so called “diabetes paradox” has been previously explained in TTS patients and is the target of many active investigations. As highlighted in the Letter to the Editor, the prevalence of diabetes mellitus in our patient population is very close to the results of prior meta‐analyses of multiple small studies of patients with TTS