In this paper we argue that the category of Stone spaces forms an interesting base category for coalgebras, in particular, if one considers the Vietoris functor as an analogue to the power set functor on the category of sets. We prove that the so-called descriptive general frames, which play a fundamental role in the semantics of modal logics, can be seen as Stone coalgebras in a natural way. T...

The article describes the making of an art piece combining stone sculpture and virtual water. The motivation for this art piece was to enrich the usual static format of a stone sculpture with a dynamic dimension. The dynamic dimension is attained with virtual water droplets running over the stone surface which behave as real water droplets. The 3-D surface of a specially carved stone sculpture ...

BACKGROUND Pulp stone, though of an unclear aetiology, is clinically common. It potentially poses procedural difficulty to the endodontist and may also be a marker of an underlying systemic condition. OBJECTIVES The study investigated pulp stone occurrence in adult restorative patients. It also highlighted the relationship between pulp stone and pristine posterior teeth, chronic periodontitis...

In spite of vast improvements in urinary stone treatment (ESWL, PNL, ureteroscopy, etc.), metabolic workup concerning the existence of stone forming risk factors are of great importance and can lead to control and even prevention of urinary stone formation in these patients. In this analytical case-control study performed on 266 persons [110 normal persons (56 males and 54 females), 76 pat...

BACKGROUND Animal studies have shown that nicotine affects the peristalsis of the ureter. The aim of the study is to analyze the effect of smoking on spontaneous passage of distal ureteral stones. METHODS 88 patients in whom distal ureteral stone below 10 mm diameter diagnosed with helical computerized tomography enhanced images were reviewed. Patients were grouped as either smokers (n:33) or...

OBJECTIVES To compare 4 ureteral occlusion devices in terms of insertion force, maneuverability, radial dilation and extraction forces, ability to prevent stone migration, and tip stiffness. METHODS The devices tested were the PercSys Accordion, Microvasive Stone Cone (7 and 10 mm), and Cook N-Trap. Using a ureteral model with an artificial stone in place, the insertion force, number of attem...

Most network intruders launch their attacks through steppingstones to reduce the risks of being discovered. To uncover such intrusions, one prevalent, challenging, and critical way is to compare an incoming connection with an outgoing connection to determine if a computer is used as stepping-stone. In this paper, we present four models to describe stepping-stone intrusion. We also propose the i...

Stone formation and nephrocalcinosis are both very common features of primary hyperoxaluria, yet the extent of each disease varies markedly between patients. Here we studied whether kidney damage from nephrocalcinosis and/or stone related events contributed to end-stage kidney disease (ESKD). Clinical information was analyzed from 348 patients enrolled in the Rare Kidney Stone Consortium Primar...