Structured Modeling with Hyperdag P Systems: Part A

P systems provide a computational model based on the structure and interaction of living cells. A P system consists of a hierarchical nesting of cell-like membranes, which can be visualized as a rooted tree. Although the P systems are computationally complete, many real world models, e.g., from socio-economic systems, databases, operating systems, distributed systems, seem to require more expressive power than provided by tree structures. Many such systems have a primary tree-like structure completed with shared or secondary communication channels. Modeling these as tree-based systems, while theoretically possible, is not very appealing, because it typically needs artificial extensions that introduce additional complexities, nonexistent in the originals. In this paper we propose and define a new model that combines structure and flexibility, called hyperdag P systems, in short, hP systems, which extend the definition of conventional P systems, by allowing dags, interpreted as hypergraphs, instead of trees, as models for the membrane structure. We investigate the relation between our hP systems and neural P systems. Despite using an apparently less powerful structure, i.e., a dag instead of a general graph, we argue that hP systems have essentially the same computational power as tissue and neural P systems. We argue that hP systems offer a structured approach to membrane-based modeling that is often closer to the behavior and underlying structure of the modeled objects. Additionally, we enable dynamical changes of the rewriting modes (e.g., to alternate between determinism and parallelism) and of the transfer modes (e.g., the switch between unicast or broadcast). In contrast, classical P systems, both tree and graph based P systems, seem to focus on a statical approach. We support our view with a simple but realistic example, inspired from computer networking, modeled as a hP system with a shared communication line (broadcast channel). In Part B of this paper we will explore this model further and support it with a more extensive set of examples

Development of Inspection Robots for Bridge Cables

This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented

Submerzni uzgoj i karakterizacija polisaharida iz gljive Grifola frondosa – primjena u kozmetičkoj industriji

Grifola frondosa (maitake) is traditionally called \u27the king of mushrooms\u27 and \u27the hen of the woods\u27. Both the fruiting bodies and the mycelium of maitake have been reported to have antitumor and antiviral activities. Recently, submerged culture processes have been developed, with the intention of providing opportunities for increased economic exploitation of maitake. Commonly the aim of these processes is to produce extracellular polysaccharides (EPS), mostly glucans, and to explore their applications, particularly in the cosmetic industry. A wide variety of EPS with different molecular chain length and chemical compositions are produced under different culture conditions. In this article, various biological and physicochemical properties of the EPS of G. frondosa (GF-EPS) are described, with a view to applications in the area of functional cosmeceuticals. The GF-EPS, together with GF mycelial extract (GF-MPS), showed antioxidative activity, stimulation of collagen biosynthetic activity, cell proliferation activity, and inhibitory activity of melanogenesis, without significant cytotoxicity. These diverse functionalities suggest that both GF-EPS and GF-MPS can be promising cosmetic ingredients.Gljivu Grifola frondosa (maitake) u Koreji tradicionalno zovu kraljicom gljiva i šumskim bogatstvom. Dokazano je da plodište i micelij gljiva maitake imaju antitumorski i antivirusni učinak. Ekonomsko iskorištenje te gljive omogućeno je submerznim uzgojem. Uobičajeni je cilj uzgoja proizvodnja ekstracelularnih polisaharida (EPS), uglavnom glukana i istraživanje mogućnosti njihove primjene u kozmetičkoj industriji. Pri raznim uvjetima proizvodnje dobivaju se ekstracelularni polisaharidi različitih duljina lanaca i kemijskoga sastava. U ovom su radu opisana razna biološka i fizikalno-kemijska svojstva ekstracelularnih polisaharida gljive Grifola frondosa (GF-EPS), te primjena u proizvodnji kozmetičkih preparata s povoljnim utjecajem na ljudsko zdravlje. Ekstracelularni polisaharidi i ekstrakt micelija gljive Grifola frondosa (GFMPS) imaju antioksidativni učinak, stimuliraju biosintezu kolagena, bujanje stanica, sprečavaju nastanak melanoma i nemaju jače citotoksično djelovanje, zbog čega su prikladni za primjenu u kozmetičkoj industriji

Towards Structured Modelling with Hyperdag P Systems

Although P systems are computationally complete, many real world models, such as socio-economic systems, databases, operating systems and distributed systems, seem to require more expressive power than provided by tree structures. Many such systems have a primary tree-like structure augmented with shared or secondary communication channels. Modelling these as tree-based systems, while theoretically possible, is not very appealing, because it typically needs artificial extensions that introduce additional complexities, inexistent in the originals. In this paper, we propose and define a new model called hyperdag P systems, in short, hP systems, which extend the definition of conventional P systems, by allowing dags, interpreted as hypergraphs, instead of trees, as models for the membrane structure. We investigate the relation between our hP systems and neural P systems. Despite using an apparently restricted structure, i.e., a dag instead of a general graph, we argue that hP systems have essentially the same computational power as tissue and neural P systems. We argue that hP systems offer a structured approach to membranebased modelling that is often closer to the behavior and underlying structure of the modelled objects

Arrhythmia surgery for atrial fibrillation associated with atrial septal defect: Right-sided maze versus biatrial maze

BackgroundAlthough it has been inferred that a biatrial maze procedure for atrial fibrillation in left-sided heart lesions may lead to better outcomes compared with a limited left atrial lesion set, it remains controversial whether the biatrial maze procedure is superior to the right atrial maze procedure in right-sided heart lesions.MethodsA retrospective review was performed for 56 adults who underwent surgical closure of atrial septal defect and various maze procedures for atrial fibrillation between June 1998 and February 2011. The median age at operation was 59 years (range, 34-79 years). Clinical manifestations of atrial fibrillation were paroxysmal in 8 patients, persistent in 15 patients, and long-standing persistent in 33 patients. A right atrial maze procedure was performed in 23 patients (group 1), and a biatrial maze procedure was performed in 33 patients (group 2). Treatment failure was defined as atrial fibrillation recurrence, development of atrial flutter or other types of atrial tachyarrhythmia, or implantation of a permanent pacemaker. The Cox proportional hazards model was used to identify risk factors for decreased time to treatment failure.ResultsDuring the median follow-up period of 49 months (range, 5-149 months), there was no early death and 1 late noncardiac death. On Cox survival model, group 1 showed a significantly decreased time to treatment failure in comparison with group 2 (hazard ratio, 5.11; 95% confidence interval, 1.59-16.44; P = .006). Maintenance of normal sinus rhythm without any episode of atrial fibrillation recurrence at 2 and 5 years postoperatively was 57% and 45% in group 1, respectively, and 82% and 69% in group 2, respectively.ConclusionsLeft-sided ablation in addition to a right atrial maze procedure leads to better electrophysiologic outcome in atrial fibrillation associated with atrial septal defect