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A 53-year-old otherwise healthy woman presents with a 2-year history of intermittent fecal incontinence. Because of embarrassment, she has curtailed her social and professional activities. Physical activity often precipitates an episode, and she wears absorbent pads. She has occasional urinary incontinence when she coughs or sneezes. There is no history of gastrointestinal or rectal surgery and no neurologic symptoms. Physical examination reveals no perianal deformity or rectal prolapse. The tone of the anal canal is adequate, whereas contractions of the anal sphincter muscle and the puborectalis muscle are weak. On the patient's bearing down, there is no rectal prolapse, and the perineal descent is approximately 2 cm. How should she be evaluated and treated? The Cl inic a l Probl e m Fecal incontinence is a devastating nonfatal illness, resulting in considerable embarrassment and anxiety in those who have it. It affects 2 to 17% of people living in the community and almost half of all nursing home residents. 1 Many affected persons do not voluntarily report fecal incontinence to their physicians and must be asked about it directly. 2 The prevalence of fecal incontinence is increased among women, the elderly, persons with poor health status or physical limitations, and those residing in nursing homes. 2 Other risk factors associated with fecal incontinence in adults include rectal radiation therapy (e.g., for prostate cancer), pregnancy, injury to the sphincter or nerve damage associated with vaginal delivery, anorectal surgical procedures (e.g., sphincterotomy for anal fissures), diarrhea alone or in association with the irritable bowel syndrome, and fecal impaction. Neurologic conditions (e.g., stroke, multiple sclerosis, spinal cord injury, and Parkinson's disease) and diabetes are also risk factors. Continence relies on the appropriate functioning of the puborectalis muscle and the internal and external anal sphincter muscles, which encircle the anal canal S t r ategie s a nd E v idence Evaluation A detailed history should be taken to assess the frequency, severity, and nature of the incontinence and the effect of incontinence on the quality of the patient's life, including an assessment of the patient's ability to leave the house for work and social activities. Patients are particularly anxious about the unpredictability of episodes of fecal incontinence and often alter their social and professional activities to avoid embar

An Expansion Term In Hamilton's Equations

For any given spacetime the choice of time coordinate is undetermined. A particular choice is the absolute time associated with a preferred vector field. Using the absolute time Hamilton's equations are $- (\delta H_{c})/(\delta q)=\dot{\pi}+\Theta\pi,$+ (\delta H_{c})/(\delta \pi)=\dot{q}$, where$\Theta = V^{a}_{.;a}$is the expansion of the vector field. Thus there is a hitherto unnoticed term in the expansion of the preferred vector field. Hamilton's equations can be used to describe fluid motion. In this case the absolute time is the time associated with the fluid's co-moving vector. As measured by this absolute time the expansion term is present. Similarly in cosmology, each observer has a co-moving vector and Hamilton's equations again have an expansion term. It is necessary to include the expansion term to quantize systems such as the above by the canonical method of replacing Dirac brackets by commutators. Hamilton's equations in this form do not have a corresponding sympletic form. Replacing the expansion by a particle number$N\equiv exp(-\int\Theta d \ta)$and introducing the particle numbers conjugate momentum$\pi^{N}$the standard sympletic form can be recovered with two extra fields N and$\pi^N$. Briefly the possibility of a non-standard sympletic form and the further possibility of there being a non-zero Finsler curvature corresponding to this are looked at.Comment: 10 page

Anorectal Disorders

This report defines criteria and reviews the epidemiology, pathophysiology, and management of the following common anorectal disorders: fecal incontinence (FI), functional anorectal pain, and functional defecation disorders. FI is defined as the recurrent uncontrolled passage of fecal material for at least 3 months. The clinical features of FI are useful for guiding diagnostic testing and therapy. Anorectal manometry and imaging are useful for evaluating anal and pelvic floor structure and function. Education, antidiarrheals, and biofeedback therapy are the mainstay of management; surgery may be useful in refractory cases. Functional anorectal pain syndromes are defined by clinical features and categorized into 3 subtypes. In proctalgia fugax, the pain is typically fleeting and lasts for seconds to minutes. In levator ani syndrome and unspecified anorectal pain, the pain lasts more than 30 minutes, but in levator ani syndrome there is puborectalis tenderness. Functional defecation disorders are defined by ≥2 symptoms of chronic constipation or irritable bowel syndrome with constipation, and with ≥2 features of impaired evacuation, that is, abnormal evacuation pattern on manometry, abnormal balloon expulsion test, or impaired rectal evacuation by imaging. It includes 2 subtypes: dyssynergic defecation and inadequate defecatory propulsion. Pelvic floor biofeedback therapy is effective for treating levator ani syndrome and defecatory disorders

On the applicability of constrained symplectic integrators in general relativity

The purpose of this note is to point out that a naive application of symplectic integration schemes for Hamiltonian systems with constraints such as SHAKE or RATTLE which preserve holonomic constraints encounters difficulties when applied to the numerical treatment of the equations of general relativity.Comment: 13 pages, change the title to be more descriptive, typos corrected, added referenc

Horizon energy and angular momentum from a Hamiltonian perspective

Classical black holes and event horizons are highly non-local objects, defined in terms of the causal past of future null infinity. Alternative, (quasi)local definitions are often used in mathematical, quantum, and numerical relativity. These include apparent, trapping, isolated, and dynamical horizons, all of which are closely associated to two-surfaces of zero outward null expansion. In this paper we show that three-surfaces which can be foliated with such two-surfaces are suitable boundaries in both a quasilocal action and a phase space formulation of general relativity. The resulting formalism provides expressions for the quasilocal energy and angular momentum associated with the horizon. The values of the energy and angular momentum are in agreement with those derived from the isolated and dynamical horizon frameworks.Comment: 39 pages, 3 figures, Final Version : content essentially unchanged but many small improvements made in response to referees, a few references adde

Kerr-CFT From Black-Hole Thermodynamics

We analyze the near-horizon limit of a general black hole with two commuting killing vector fields in the limit of zero temperature. We use black hole thermodynamics methods to relate asymptotic charges of the complete spacetime to those obtained in the near-horizon limit. We then show that some diffeomorphisms do alter asymptotic charges of the full spacetime, even though they are defined in the near horizon limit and, therefore, count black hole states. We show that these conditions are essentially the same as considered in the Kerr/CFT corresponcence. From the algebra constructed from these diffeomorphisms, one can extract its central charge and then obtain the black hole entropy by use of Cardy's formula.Comment: 19 pages, JHEP3, no figures. V2: References added, small typos fixe

Association of Phosphate-Containing versus Phosphate-Free Solutions on Ventilator Days in Patients Requiring Continuous Kidney Replacement Therapy

Background and objectives Hypophosphatemia is commonly observed in patients receiving continuous KRT. Patients who develop hypophosphatemia may be at risk of respiratory and neuromuscular dysfunction and therefore subject to prolongation of ventilator support. We evaluated the association of phosphate-containing versus phosphate-free continuous KRT solutions with ventilator dependence in critically ill patients receiving continuous KRT. Design, setting, participants, & measurements Our study was a single-center, retrospective, pre-post cohort study of adult patients receiving continuous KRT and mechanical ventilation during their intensive care unit stay. Zeroinflated negative binomial regression with and without propensity score matching was used to model our primary outcome: ventilator-free days at 28 days. Intensive care unit and hospital lengths of stay as well as hospital mortality were analyzed with a t test or a chi-squared test, as appropriate. Results We identified 992 eligible patients, of whom 649 (65%) received phosphate-containing solutions and 343 (35%) received phosphate-free solutions. In multivariable models, patients receiving phosphate-containing continuous KRT solutions had 12% (95% confidence interval, 0.17 to 0.47) more ventilator-free days at 28 days. Patients exposed to phosphate-containing versus phosphate-free solutions had 17% (95% confidence interval, 20.08 to 20.30) fewer days in the intensive care unit and 20% (95% confidence interval, 2 0.12 to 20.32) fewer days in the hospital. Concordant results were observed for ventilator-free days at 28 days in the propensity score matched analysis. There was no difference in hospital mortality between the groups. Conclusions The use of phosphate-containing versus phosphate-free continuous KRT solutions was independently associated with fewer ventilator days and shorter stay in the intensive care unit

Quantization of Nonstandard Hamiltonian Systems

The quantization of classical theories that admit more than one Hamiltonian description is considered. This is done from a geometrical viewpoint, both at the quantization level (geometric quantization) and at the level of the dynamics of the quantum theory. A spin-1/2 system is taken as an example in which all the steps can be completed. It is shown that the geometry of the quantum theory imposes restrictions on the physically allowed nonstandard quantum theories.Comment: Revtex file, 23 pages, no figure

Linear stability of the Lagrangian triangle solutions for quasihomogeneous potentials

In this paper we study the linear stability of the relative equilibria for homogeneous and quasihomogeneous potentials. Firstly, in the case the potential is a homogeneous function of degree $-a$, we find that any relative equilibrium of the $n$-body problem with $a>2$ is spectrally unstable. We also find a similar condition in the quasihomogeneous case. Then we consider the case of three bodies and we study the stability of the equilateral triangle relative equilibria. In the case of homogeneous potentials we recover the classical result obtained by Routh in a simpler way. In the case of quasihomogeneous potentials we find a generalization of Routh inequality and we show that, for certain values of the masses, the stability of the relative equilibria depends on the size of the configuration.Comment: 21 pages 4 figure

A Hamilton-Jacobi Formalism for Thermodynamics

We show that classical thermodynamics has a formulation in terms of Hamilton-Jacobi theory, analogous to mechanics. Even though the thermodynamic variables come in conjugate pairs such as pressure/volume or temperature/entropy, the phase space is odd-dimensional. For a system with n thermodynamic degrees of freedom it is (2n+1)-dimensional. The equations of state of a substance pick out an n-dimensional submanifold. A family of substances whose equations of state depend on n parameters define a hypersurface of co-dimension one. This can be described by the vanishing of a function which plays the role of a Hamiltonian. The ordinary differential equations (characteristic equations) defined by this function describe a dynamical system on the hypersurface. Its orbits can be used to reconstruct the equations of state. The `time' variable associated to this dynamics is related to, but is not identical to, entropy. After developing this formalism on well-grounded systems such as the van der Waals gases and the Curie-Weiss magnets, we derive a Hamilton-Jacobi equation for black hole thermodynamics in General Relativity. The cosmological constant appears as a constant of integration in this picture.Comment: Minor typos fixe