We present a simple closed-form expression for the reflectivity horn a multilayer which includes the effects of absorption, refraction, surface and substrate reflections but neglects dynamical effects. This expression reproduces the exact dynamical calculation except for the regions near the critical angle and for intense Bragg reflections. The expression is generalized to include cumulative in...

The paper analyzes errors in retrievals of cloud liquid water content (Ql) and precipitation flux (R) based on three different sets of parameters: a) radar reflectivity, Z, b) radar reflectivity and Doppler velocity, V , and c) radar reflectivity and Doppler velocity spectrum width, σ d d. As radar reflectivity represents the sixth moment of the drop size distribution (DSD), one can expect it t...

In some of the recently-developed algorithms for convex parametric quadratic programs it is implicitly assumed that the intersection of the closures of two adjacent critical regions is a facet of both closures; this will be referred to as the facet-to-facet property. It is shown by an example, whose solution is unique, that the facet-to-facet property does not hold in general, and consequently,...

BACKGROUND Facet (zygapophysial) joints may be clinically important sources of chronic cervical spinal pain. Previous studies have demonstrated the value and validity of controlled, comparative local anesthetic blocks in the diagnosis of facet joint pain, and reported an overall prevalence of 36% to 67% facet joint involvement in cervical spinal pain. The reports of lumbar facet joint-involveme...

CONTEXT Facet or zygapophysial joint blocks are used extensively in the evaluation of chronic spinal pain. However, there is a continuing debate about the value and validity of facet joint blocks in the diagnosis of chronic spinal pain. The value of diagnostic facet joint injections may have been overlooked in the medical literature. OBJECTIVES To determine the accuracy of facet joint blocks ...

BACKGROUND The purpose was to explore possible risk factors of facet joint violation induced by adjacent superior vertebral pedicle screw during the minimally invasive surgery transforaminal lumbar interbody fusion (MIS-TLIF). METHODS A total of 69 patients with lumbar degenerative disease, who underwent MIS-TLIF were retrospectively reviewed. Postoperative computed tomography images were use...

We describe a software reuse architecture supporting component retrieval by facet classes. The facets are organized into a lattice of facet value sets and facet n-tuples. The query mechanism supports both precise retrieval and flexible browsing. "_= _'

A retrospective cohort study. Plated cervical laminoplasty is an increasingly common technique. A unique facet joint disturbance induced by lateral mass miniscrews penetrating articular surface was noticed. Facet joints are important to maintain cervical spine stability and kinetic balance. Whether this facet joint disturbance could affect clinical and radiologic results is still unknown. The o...

BACKGROUND AND PURPOSE The clinical impact of facet joint bone scan activity is not fully understood. The hypothesis of this study is that facet joints targeted for percutaneous treatment in clinical practice differ from those with reported activity on technetium Tc99m methylene diphosphonate SPECT/CT. MATERIALS AND METHODS All patients with a technetium Tc99m methylene diphosphonate SPECT/CT...

Facet joint injection is considered to be a safe procedure. There have been some reported cases of facet joint pyogenic infection and also 3 cases of facet joint infection spreading to paraspinal muscle and epidural space due to intra-articular injections. To the author's knowledge, paraspinal and epidural abscesses after facet joint injection without facet joint pyogenic infection have not bee...