Characteristics and identification of sites of chagasic ventricular tachycardia by endocardial mapping

OBJECTIVE: To study electrophysiological characteristics that enable the identification and ablation of sites of chagasic tachycardia. METHODS: Thirty-one patients with chronic Chagas' heart disease and sustained ventricular tachycardia (SVT) underwent electrophysiological study to map and ablate that arrhythmia. Fifteen patients had hemodinamically stable SVT reproducible by programmed ventricular stimulation, 9 men and 6 women with ages ranging from 37 to 67 years and ejection fraction varying from 0.17 to 0.64. Endocardial mapping was performed during SVT in all patients. Radiofrequency (RF) current was applied to sites of presystolic activity of at least 30 ms. Entrainment was used to identify reentrant circuits. In both successful and unsuccessful sites of RF current application, electrogram and entrainment were analyzed. RESULTS: Entrainment was obtained during all mapped SVT. In 70.5% of the sites we observed concealed entrainment and ventricular tachycardia termination in the first 15 seconds of RF current application. In the unsuccessful sites, significantly earlier electrical activity was seen than in the successful ones. Concealed entrainment was significantly associated with ventricular tachycardia termination. Bystander areas were not observed. CONCLUSION: The reentrant mechanism was responsible for the genesis of all tachycardias. In 70.5% of the studied sites, the endocardial participation of the slow conducting zone of reentrant circuits was shown. Concealed entrainment was the main electrophysiological parameter associated with successful RF current application. There was no electrophysiological evidence of bystander regions in the mapped circuits of SVT.

Safety management of cranes on construction sites in Portugal: Critical factors of safety

The evolution of the construction caused a need to use more effective equipments, capable of meeting the increasingly demanding deadlines for the completion of works. In this context, the safety and efficiency of equipment have become key aspects in order to optimize the execution time of the works, as well as reducing labor costs and loss of materials. With the evolution of construction and construction processes, cranes have come to represent a signal of the construction of buildings, revealing to be, in most of the cases, the main equipment of construction sites. Currently, some engineers revels some apprehension regarding the use and handling of cranes which is natural and acceptable, since an equipment failure can lead to serious or fatal accidents. The factors affecting safety management of the cranes in construction sites were investigated, identified, classified and evaluated according to their degree of importance, through interviews with representatives of the general contractors of a set of selected construction sites.

Experimental investigation of heat transfer characteristics from arrays of free impinging circular jets and hole channels

Free Tube Jet - Impingemenet - Heat Transfer - Arrary - Infrared Techuique - Hole Channels - Heat Transfer Uniformaty

Sites of the reserve phase: Pine Lawn Valley, western New Mexico / [by] Paul S. Martin [and] John B. Rinaldo.

v.38:no.3(1950)

Late Mogollon communities: four sites of the Tularosa phase, western New Mexico / [by] Paul S. Martin, John B. Rinaldo [and] Eloise R. Barter.

v.49:no.1(1957)

Dispersão larval radial pós-alimentar em Lucilia cuprina (Diptera, Calliphoridae): profundidade, peso e distância de enterramento para pupação

Blowflies utilize discrete and ephemeral sites for breeding and larval nutrition. After the exhaustion of food, the larvae begin dispersing to search for sites to pupate or for additional food source, process referred as postfeeding larval dispersal. Some aspects of this process were investigated in Lucilia cuprina (Wiedemann, 1830), utilizing a circular arena to permit the radial dispersion of larvae from the food source in the center. To determine the localization of each pupa, the arena was split into 72 equal sectors from the center. For each pupa, distance from the center of arena, weight and depth were determined. Statistical tests were performed to verify the relation among weight, depth and distance of burying for pupation. It was verified that the larvae that disperse farthest are those with lowest weights. The majority of individuals reached the depth of burying for pupation between 7 and 18 cm. The study of this process of dispersion can be utilized in the estimation of postmortem interval (PMI) for human corpses in medico-criminal investigations.

Cochise and Mogollon sites, Pine Lawn Valley, western New Mexico / Paul S. Martin, John B. Rinaldo [and] Ernst Antevs.

v.38:no.1(1949)

Indian sites and chipped stone materials in the northern Lake Michigan area / Lewis R. Binford and George I. Quimby.

v.36:no.12(1963)

Hilltop terrace sites of Oaxaca, Mexico : intensive surface survey at Guirâun, El Palmillo and the Mitla Fortress / Gary M. Feinman and Linda M. Nicholas.

n.s. no.37(2004)

An ecological and comparative analysis of parasites in juvenile Mugil liza (Pisces, Mugilidae) from two sites in Samborombón bay, Argentina

ABSTRACT Mugil liza Valenciennes, 1836 is an economically important food fish and has been recommended for aquaculture in South America. A total of 278 fishes were collected in the spring and summer of 2009 and 2010. These fish were sorted into sample groups according to their size class. We used Bayesian statistics and 95% credible intervals for each parameter tested were calculated. Fish studied harbored a total of 15 different species of parasites. Diversity of parasite species found on Mugil liza was greatest at the S.R.C. collection site, but evidenced a lower species richness than at A.R. site. The 1st size fishes of both sites evidenced greater parasite diversity than either 2nd or 3rd size fish. Differences observed could be explained by the different use of habitat types at the two sites or differential susceptibility to infection by parasites. The dominance of D. fastigatainfluenced observed results of lower community diversity indexes. New works elucidating different parasite life cycles within juvenile and adults ofM. liza in Argentina, promise to be important for determining the risk of the parasitism by zoonotic metacercariae A. (P.) longa and use of this fish as food and an economic resource, and the possible use of mullet parasites in other promising fields as indicators of biodiversity, and/ or water contamination.

La raó circular

És un text epistemològic sobre les qüestions cognitives circulars que apareixen: a) Quan el subjecte forma part de l’objecte estudiat; b) En la recerca de les bases del coneixement; c) Al voler justificar la inducció; d) En algunes interpretacions filosòfiques i científiques. S’hi explica l’estat del punt a) el més problemàtic, i s’aclareixen els altres tres punts: els b) i c) pel fet científic que l’evolució cognitiva humana ha anat acoblada a l’evolució biològica, la qual ha generat els a priori kantians i altres innatismes. El d) perquè la formació del coneixement i de la ciència es progressiva, passant una i altra vegada sobre el que ja s’havia tractat però ascendint alhora i ampliant el panorama, tal com fa una escala de cargol.