Swanson was partially motivated by the analogous question for “Frobenius powers”, which has important applications to the theory of tight closure (the so-called “localization problem;” see [HH, Section 4]). Suppose now that R has prime characteristic p > 0 and q is a power of p. The Frobenius power I [q] of an ideal I is the ideal generated by all the qth powers of the elements (equivalently, t...

We show that the property of F-regularity does not deform, and thereby settle a longstanding open question in the theory of tight closure. Specifically, we construct a three dimensional N-graded domain R which is not F-regular (or even F-pure), but has a quotient R=tR which is F-regular. Examples are constructed over fields of characteristic p > 0, as well as over fields of characteristic zero.

BACKGROUND We developed a non-survival in vivo model for testing of gastric natural orifice translumenal endoscopic surgery (NOTES) closures based on the gastric yield pressure. The aim of this study was to test our model comparing different endoscopic closure techniques with surgical closure of a NOTES gastric incision. METHODS Laparotomy was performed in 30 pigs. One tube for air inflation ...

We examine some recent work of Phillip Griffith on étale covers and fibered products from the point of view of tight closure theory. While it is known that cyclic covers of Gorenstein rings with rational singularities are Cohen-Macaulay, we show this is not true in general in the absence of the Gorenstein hypothesis. Specifically, we show that the canonical cover of a Q-Gorenstein ring with rat...

A 70-year-old male patient was referred for closure of patent foramen ovale after recurrent transient cerebral ischaemia. A 25-mm Amplatzer PFO occluder was implanted. Thereafter and due to his age and a history of chest pain during the past six months, we performed coronary angiograms which demonstrated tight stenosis of the distal part and significant stenosis of the proximal part of the righ...

In this paper, the notion of closure operators of matroids  is generalized to fuzzy setting  which is called $M$-fuzzifying closure operators, and some properties of $M$-fuzzifying closure operators are discussed. The $M$-fuzzifying matroid induced by an $M$-fuzzifying closure operator can induce an $M$-fuzzifying closure operator. Finally, the characterizations of $M$-fuzzifying acyclic matroi...

background:   many of the patients with tethered cord syndrome (tcs) are admitted because of neurological symptoms, while some are admitted because of their orthopedic, urologic, anorectal, and dermatologic manifestations.consequently, this study aimed to evaluate the importance of early diagnosis and treatment of tethered cord syndrome on patient outcome. methods: fourty-three patients who und...

in this paper energy bands and berry curvature of graphene was studied. desired hamiltonian regarding the next-nearest neighbors obtained by tight binding model. by using the second quantization approach, the transformation matrix is calculated and the hamiltonian of system is diagonalized. with this hamiltonian, the band structure and wave function can be calculated. by using calculated wave f...

Abdominal closure in children less than 10 kg following liver or kidney transplantation can be challenging. Excessive pressure attained from a tight closure can result in abdominal compartment syndrome, graft compromise and loss. Concerns over using prosthetic patches are that of infection and dehiscence. We report a series of definitive abdominal wall closure using a biodegradable membrane fro...