The influence of inhomogeneities on the cardiac-magnetic-field distribution

Numerical computations were performed on the magnetic field generated by the heart during ventricular depolarization. The purpose of this study was to investigate the contribution of inhomogeneities in the volume conductor to the total field and to establish the influence of gradiometers as used in experimental recordings

A LADM-based temporal cadastral information system for modelling of easement rights – A case study of Turkey

Type people to land relations are dynamic and, as a consequence, the nature of land title and cadastral data is of a dynamic nature. Land title and cadastral data are core components for a lot of property applications (e.g. taxation, valuation, mortgage). Those applications require up to date, complete and reliable data–including temporal data as in use in application forms and transactions. In this paper, the modelling of Rights, Restrictions and Responsibilities (RRR) is discussed with a focus on the modelling of easement rights in a case study in Turkey. Functional requirements with respect to the characteristics of easement rights are investigated based upon interviews with professional experts in the public and private sector. Then a prototype model was built based on a simple implementation of the Land Administration Domain Model (LADM) RRR classes and by conforming to the national cadastral data management standards related to land registration systems. This new proposed model includes temporal cadastral attributes related to easements. This is materialised in the ‘Administrative Package’ and illustrated in the Turkey LADM country profile. We show that the LADM can be used to describe for the time dimension of cadastral information in Turkey, but that there are semantic differences, similarities and mismatches of classes and attributes between the LADM and the cadastral information system in Turkey. Proposed LADM-based model for the time dimension of cadastral information will be of immense advantage to land administrators, the governments and land users in Turkey

Closed-form analytical expressions for the potential fields generated by triangular monolayers with linearly distributed source strength

The solution of the mixed boundary value problem of potential theory involves the computation of the potential field generated by monolayer and double layer source distributions on surfaces at which boundary conditions are known. Closed-form analytical expressions have been described in the literature for the potential field generated by double layers having a linearly distributed strength over triangular source elements. This contribution presents the corresponding expression for the linearly distributed monolayer strength. The solution is shown to be valid for all observation points in space, including those on the interior, edges and vertices of the source triangle

Prognostic value of bcl-2 expression in invasive breast cancer.

Expression of the bcl-2 proto-oncogene was studied immunohistochemically in 251 invasive ductal breast carcinomas (median follow-up time 91 months, range 24-186 months) and the results were correlated with clinicopathological data and prognostic variables. Sixty-three (25%) tumours were scored bcl-2 negative and 188 (75%) tumours were bcl-2 positive. No relationship could be observed between bcl-2 status and tumour grade, pTNM staging or menopausal status. A strong positive relationship was demonstrated between bcl-2 immunoreactivity and oestrogen receptor status (P < 0.001) and progesterone receptor status (P < 0.001). No prognostic value was demonstrated for bcl-2 expression on disease-free survival and overall survival in axillary node-negative breast cancer patients. However, in axillary node-positive breast cancer patients multivariate analysis demonstrated absence of bcl-2 expression to be independently related to shortened disease-free survival (P = 0.003) and shortened overall survival (P < 0.001). Our results suggest a potential important role for bcl-2 expression as a modulator of response to adjuvant therapy in breast cancer

Atrial repolarization as observable in the PQ interval

Objective: To study the involvement of atrial repolarization in body surface potentials. Methods: Electrocardiograms of healthy subjects were recorded using a 64-lead system. The data analysis focused on the PQ intervals, while devoting special attention to the low-amplitude signals during the PQ segment: the segment from the end of the P wave till onset QRS. The data were analyzed by inspecting body surface potential maps and the XYZ signals of the vector cardiogram. Results: Standard P wave features exhibited normal values. The local potential extremes were found at positions not sampled by the standard leads. The PQ segment was found to be not iso-electric, the potential distribution being very similar to that at the timing of apex P but for a reversed polarity and a 3-fold lower magnitude. Conclusion: The results demonstrate a significant involvement of atrial repolarization during the PQ interval, with essentially non-concomitant atrial T waves