Many-body localization: stability and instability.

Rare regions with weak disorder (Griffiths regions) have the potential to spoil localization. We describe a non-perturbative construction of local integrals of motion (LIOMs) for a weakly interacting spin chain in one dimension, under a physically reasonable assumption on the statistics of eigenvalues. We discuss ideas about the situation in higher dimensions, where one can no longer ensure that interactions involving the Griffiths regions are much smaller than the typical energy-level spacing for such regions.

Diagonalization and Many-Body Localization for a Disordered Quantum Spin Chain.

We consider a weakly interacting quantum spin chain with random local interactions. We prove that many-body localization follows from a physically reasonable assumption that limits the extent of level attraction in the statistics of eigenvalues. In a Kolmogorov-Arnold-Moser-style construction, a sequence of local unitary transformations is used to diagonalize the Hamiltonian by deforming the initial tensor-product basis into a complete set of exact many-body eigenfunctions.

Intraoperative ultrasound is associated with clear lumpectomy margins for palpable infiltrating ductal breast cancer.

Objective: To evaluate the efficacy of intraoperative ultrasound in obtaining adequate surgical margins in women undergoing lumpectomy for palpable breast cancer.

Summary Background Data: Adequacy of surgical margins is a subject of debate in the literature for women undergoing breast-conserving therapy. The emerging technology of intraoperative ultrasound-guided surgery lends itself well to a prospective study evaluating surgical accuracy and margin status after lumpectomy.

Association of infiltrating lobular carcinoma with positive surgical margins after breast-conservation therapy.

Objective: To determine whether infiltrating lobular carcinoma (ILC) is associated with high positive-margin rates for single-stage lumpectomy procedures, and to define clinical, mammographic, or histologic characteristics of ILC that might influence the positive-margin rate, thereby affecting treatment decisions.

Summary Background Data: Infiltrating lobular cancer represents approximately 10% of all invasive breast carcinomas and is often poorly defined on gross examination.

Methods: A group of 47 patients with biopsy-proven ILC undergoing breast-conservation therapy (BCT) at the University of Virginia Health Sciences Center between 1975 and 1999 was compared with a group of 150 patients with infiltrating ductal cancer undergoing BCT during the same time period.

Interventions to reduce decibel levels on patient care units.

The University of Virginia Health System inpatient satisfaction survey identified noise as the most important irritant to surgical inpatients. Analysis of the level and pattern of noise on patient floors and intensive care units was done with baseline measurements followed by then two separate interventions: 1) education of nursing and physician staff 2) closing patient room doors. A decibel meter (M-27 Dosimeter) recorded the noise level over 24 hours.