103 research outputs found
Treatment Considerations for Mandibulectomy Patients
Prosthetic rehabilitation of patients after resection of the mandible due to operation of malignant tumors usually poses a great problem. Loss of tissues and damage caused by radiotherapy cause various functional deficiencies and dysfunction in the stomatognathic system. The study concerned treatment of a group of mandibulectomy patients with problems related mainly to restoration of jaw relationship, lack of occlusion and dysfunctions. In the escamined cases immediate or delayed reconstructive surgery had been completed before prosthetics to treat mandibular discontinuity defects. Unfortunately, many of the patients exibit lack of occlusion, mandibular deviations and torque due to incorrect muscle activity.
Prosthetic management was part of a multidisciplinary approach to the problem. Treatment included myotherapy, gradual occlusal rearrangement with the use of therapeutic and corrective splints, special appliances and prostheses with leading inclined planes and guiding surfaces. The degree of success was related to the location and extent of the mandibular resection, the shape of the bone
transplants and presence or absence of natural teeth. The aims of treatment realised were the restoration of acceptable occlusion and improved functional efficiency of the masticatory system
Endocrine therapy in epithelial ovarian cancer
INTRODUCTION: The estrogen receptor (ER) is expressed at high levels in many epithelial ovarian cancers (EOC) and represents a potential target for endocrine therapy. Both anti-estrogens and aromatase inhibitors have been evaluated in phase II clinical trials. Areas covered: We present an overview of the phase II and phase III trials of anti-estrogens (tamoxifen and fulvestrant) and aromatase inhibitors (letrozole, anastrazole and exemestane) undertaken in epithelial ovarian cancer identified through a Pubmed search. We describe predictive biomarkers that are being investigated to identify responsive cancers. Expert commentary: The efficacy of endocrine therapy in epithelial ovarian cancer is likely to be confined to histological subtypes with the highest ER expression while low grade serous ovarian cancer appears to be one subgroup with good sensitivity to these agents. The low toxicity profile of these agents is favourable although their use is unlicensed and the optimal setting undefined. Prospective clinical trials of endocrine agents in the early relapse and maintenance settings are urgently required to establish their definitive role in the management of epithelial ovarian cancer
Quadratic Models for Portfolio Credit Risk with Shot-Noise Effects
We propose a reduced form model for default that allows us to derive closed-form solutions to all the key ingredients in credit risk modeling: risk-free bond prices, defaultable bond prices (with and without stochastic recovery) and probabilities of survival. We show that all these quantities can be represented in general exponential quadratic forms, despite the fact that the intensity is allowed to jump producing shot-noise effects. In addition, we show how to price defaultable digital puts, CDSs and options on defaultable bonds. Further on, we study a model for portfolio credit risk where we consider both firm specific and systematic risks. The model generalizes the attempt from Duffie and Garleanu (2001). We find that the model produces realistic default correlation and clustering of defaults. Then, we show how to price first-to-default swaps, CDOs, and draw the link to currently proposed credit indices
Light traffic approximations in general stationary single-server queues
This paper complements two previous studies (Daley and Rolski, 1984, 1991) by indicating the extent to which characteristics of a general stationary point process taken as the arrival process of a single-server queue influence light traffic limit theorems for the two essentially distinct schemes of dilation and thinning as routes to the limit. Properties of both the work-load and the waiting-time processes are derived, reflecting respectively the stationary time-sampling frame that may be appropriate for monitoring the system as a whole, and the customer-sampling frame (Palm distributions). Substantially different results can come from these two different views, and when compounded with the different approaches to the light traffic limits, no single light traffic scenario emerges.G/GI/1 queue stationary point process with multiple points light traffic queue with batch arrivals
Long-Range Dependence in a Cox Process Directed by a Markov Renewal Process
A Cox process NCox directed by a stationary random measure ξ has second
moment var NCox(0,t]=E(ξ(0,t])+var ξ(0,t], where by
stationarity E(ξ(0,t])=(const.)t=E(NCox(0,t]), so long-range dependence (LRD) properties of
NCox coincide with LRD properties of the random measure ξ.
When ξ(A)=∫AνJ(u)du is determined by a density that depends
on rate parameters νi(i∈) and the current state J(⋅)
of an -valued stationary irreducible Markov renewal process (MRP) for
some countable state space (so J(t) is a stationary semi-Markov
process on ), the random measure is LRD if and only if each (and then
by irreducibility, every) generic return time Yjj(j∈X) of the
process for entries to state j has infinite second moment, for which a
necessary and sufficient condition when is finite is that at least
one generic holding time Xj in state j, with distribution function (DF)\
Hj, say, has infinite second moment (a simple example shows that this
condition is not necessary when is countably infinite).
Then, NCox has the same Hurst index as the MRP NMRP that counts the jumps
of J(⋅), while as t→∞, for finite ,
var NMRP(0,t]∼2λ2∫0t(u)du,
var NCox(0,t]∼2∫0t∑i∈(νi−ν¯)2ϖiℋi(t)du,
where
ν¯=∑iϖiνi=E[ξ(0,1]],
ϖj=Pr{J(t)=j},1/λ=∑jpˇjμj,
μj=E(Xj),
{pˇj}
is the stationary distribution for the embedded jump process
of the MRP, ℋj(t)=μi−1∫0∞min(u,t)[1−Hj(u)]du, and
(t)∼∫0tmin(u,t)[1−Gjj(u)]du/mjj∼∑iϖiℋi(t)
where Gjj is the
DF and mjj the mean of the generic return time Yjj of the MRP
between successive
entries to the state j. These two variances are of similar order
for t→∞ only when each ℋi(t)/(t) converges to some
[0,∞]-valued constant, say, γi, for t→∞
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