926 research outputs found
Diagnostic Strategies for Postmenopausal Bleeding
Postmenopausal bleeding (PMB) is a common clinical problem. Patients with PMB have 10%-15% chance of having endometrial carcinoma and therefore the diagnostic workup is aimed at excluding malignancy. Patient characteristics can alter the probability of having endometrial carcinoma in patients with PMB; in certain groups of patients the incidence has been reported to be as high as 29%. Transvaginal sonography (TVS) is used as a first step in the diagnostic workup, but different authors have come to different conclusions assessing the accuracy of TVS for excluding endometrial carcinoma. Diagnostic procedures obtaining material for histological assessment (e.g., dilatation and curettage, hysteroscopy, and endometrial biopsy) can be more accurate but are also more invasive. The best diagnostic strategy for diagnosing endometrial carcinoma in patients with PMB still remains controversial. Future research should be focussed on achieving a higher accuracy of different diagnostic strategies
Steklov problem on differential forms
In this paper we study spectral properties of Dirichlet-to-Neumann map on
differential forms obtained by a slight modification of the definition due to
Belishev and Sharafutdinov. The resulting operator is shown to be
self-adjoint on the subspace of coclosed forms and to have purely discrete
spectrum there.We investigate properies of eigenvalues of and prove a
Hersch-Payne-Schiffer type inequality relating products of those eigenvalues to
eigenvalues of Hodge Laplacian on the boundary. Moreover, non-trivial
eigenvalues of are always at least as large as eigenvalues of
Dirichlet-to-Neumann map defined by Raulot and Savo. Finally, we remark that a
particular case of -forms on the boundary of -dimensional manifold
shares a lot of important properties with the classical Steklov eigenvalue
problem on surfaces.Comment: 18 page
Learning from failure
We study decentralized learning in organizations. Decentralization is captured through a symmetry constraint on agents’ strategies. Among such attainable strategies, we solve for optimal and equilibrium strategies. We model the organization as a repeated game with imperfectly observable actions. A fixed but unknown subset of action profiles are successes and all other action profiles are failures. The game is played until either there is a success or the time horizon is reached. For any time horizon, including infinity, we demonstrate existence of optimal attainable strategies and show that they are Nash equilibria. For some time horizons, we can solve explicitly for the optimal attainable strategies and show uniqueness. The solution connects the learning behavior of agents to the fundamentals that characterize the organization: Agents in the organization respond more slowly to failure as the future becomes more important, the size of the organization increases and the probability of success decreases.Game theory
Structure of the alexithymic brain:A parametric coordinate-based meta-analysis
Alexithymia refers to deficiencies in identifying and expressing emotions. This might be related to changes in structural brain volumes, but its neuroanatomical basis remains uncertain as studies have shown heterogeneous findings. Therefore, we conducted a parametric coordinate-based meta-analysis. We identified seventeen structural neuroimaging studies (including a total of 2586 individuals with different levels of alexithymia) investigating the association between gray matter volume and alexithymia. Volumes of the left insula, left amygdala, orbital frontal cortex and striatum were consistently smaller in people with high levels of alexithymia. These areas are important for emotion perception and emotional experience. Smaller volumes in these areas might lead to deficiencies in appropriately identifying and expressing emotions. These findings provide the first quantitative integration of results pertaining to the structural neuroanatomical basis of alexithymia
Cost analysis of laparoscopic lavage compared with sigmoid resection for perforated diverticulitis in the Ladies trial
Background: Laparoscopic peritoneal lavage is an alternative to sigmoid resection in selected patients presenting with purulent peritonitis from perforated diverticulitis. Although recent trials have lacked superiority for lavage in terms of morbidity, mortality was not compromised, and beneficial secondary outcomes were shown. These included shorter duration of surgery, less stoma formation and less surgical reintervention (including stoma reversal) for laparoscopic lavage versus sigmoid resection respectively. The cost analysis of laparoscopic lavage for perforated diverticulitis in the Ladies RCT was assessed in the present study. Methods: This study involved an economic evaluation of the randomized LOLA (LaparOscopic LAvage) arm of the Ladies trial (comparing laparoscopic lavage with sigmoid resection in patients with purulent peritonitis due to perforated diverticulitis). The actual resource use per individual patient was documented prospectively and analysed (according to intention-to-treat) for up to 1 year after randomization. Results: Eighty-eight patients were randomized to either laparoscopic lavage (46) or sigmoid resection (42). The total medical costs for lavage were lower (mean difference € − 3512, 95 per cent bias-corrected and accelerated c.i. −16 020 to 8149). Surgical reintervention increased costs in the lavage group, whereas stoma reversal increased costs in the sigmoid resection group. Differences in favour of laparoscopy were robust when costs were varied by ±20 per cent in a sensitivity analysis (mean cost differ
Dichotomous Hamiltonians with Unbounded Entries and Solutions of Riccati Equations
An operator Riccati equation from systems theory is considered in the case
that all entries of the associated Hamiltonian are unbounded. Using a certain
dichotomy property of the Hamiltonian and its symmetry with respect to two
different indefinite inner products, we prove the existence of nonnegative and
nonpositive solutions of the Riccati equation. Moreover, conditions for the
boundedness and uniqueness of these solutions are established.Comment: 31 pages, 3 figures; proof of uniqueness of solutions added; to
appear in Journal of Evolution Equation
Prediction of an excessive response in in vitro fertilization from patient characteristics and ovarian reserve tests and comparison in subgroups: an individual patient data meta-analysis.
postprin
A Structured Assessment to Decrease the Amount of Inconclusive Endometrial Biopsies in Women with Postmenopausal Bleeding
Objective. To determine whether structured assessment of outpatient endometrial biopsies decreases the number of inconclusive samples. Design. Retrospective cohort study. Setting. Single hospital pathology laboratory. Population. Endometrial biopsy samples of 66 women with postmenopausal bleeding, collected during the usual diagnostic work-up an
- …
