Classical objects in computational geometry are defined by explicit relations. Several years ago the pioneering works of T. Asano, J. Matoušek and T. Tokuyama introduced “implicit computational geometry” in which the geometric objects are defined by implicit relations involving sets. An important member in this family is called “a zone diagram”. The implicit nature of zone diagrams implies, as ...

BACKGROUND To examine histomorphometrically the parapapillary region in human eyes. METHODOLOGY/PRINCIPAL FINDINGS The histomorphometric study included 65 human globes (axial length:21-37 mm). On anterior-posterior histological sections, we measured the distance Bruch's membrane end (BME)-optic nerve margin ("Gamma zone"), BME-retinal pigment epithelium (RPE) ("Beta zone"), BME-beginning of n...

A zone diagram of order n is a relatively new concept which was first defined and studied by T. Asano, J. Matoušek and T. Tokuyama. It can be interpreted as a state of equilibrium between n mutually hostile kingdoms. Formally, it is a fixed point of a certain mapping. These authors considered the Euclidean plane and proved the existence and uniqueness of zone diagrams there. In the present pape...

the relations of fibrolite-biotite are discussed by presenting data from the ardara aureole, nw ireland. biotite-fibrolite intergrowths are developed in all three aureole zones including: the outer kyanite-bearing andalusite zone, the middle kyanite-free andalusite zone and the inner prismatic sillimanite zone. a strain-assisted mechanism is proposed for the fibrolitisation of biotite in the ar...

Habitability varies dramatically with location and time in the universe. This was recognized centuries ago, but it was only in the last few decades that astronomers began to systematize the study of habitability. The introduction of the concept of the habitable zone was key to progress in this area. The habitable zone concept was first applied to the space around a star, now called the Circumst...

marginal zone lymphoma (mzl) accounts for between 5% and 17% of all non-hodgkin lymphomas (nhl). w e reported a rare case of marginal zone lymphoma presenting with bilateral ear erythema and swelling. the case was a 79-year-old man who suffered from progressive bilateral ear erythema and swelling since 2 years ago. physical examination was remarkable for erythmatous, edematous and non-tender au...

tourmaline can be found as an accessory mineral in a variety of rocks including leucogranite, pegmatite, quartz veins, and metamorphiccountry rocks in hajiabad-dehgah area in se of boroujerd city. tourmaline in pegmatites is coarse-grained, subhedral to euhedral, anddisplays strong to moderate pleochroic blue rimmed by olive green. in contrast, tourmalines from leucogranite, quartz-veins, and h...

in order to study of biostratigraphy and age dating of kazhdumi formation, based on planktonic foraminifera and correlation of identified biozones with global standard biozones, this formation at tang-e-maghar have been studied. in this study 73 samples of kazhdumi formation, with 270 meter thickness, have been collected. the main lithological units at the studied section consist of the black b...