635 research outputs found
Noisy Relativistic Quantum Games in Noninertial Frames
The influence of noise and of Unruh effect on quantum Prisoners' dilemma is
investigated both for entangled and unentangled initial states. The noise is
incorporated through amplitude damping channel. For unentangled initial state,
the decoherence compensates for the adverse effect of acceleration of the frame
and the effect of acceleration becomes irrelevant provided the game is fully
decohered. It is shown that the inertial player always out scores the
noninertial player by choosing defection. For maximally entangled initially
state, we show that for fully decohered case every strategy profile results in
either of the two possible equilibrium outcomes. Two of the four possible
strategy profiles become Pareto Optimal and Nash equilibrium and no dilemma is
leftover. It is shown that other equilibrium points emerge for different region
of values of decoherence parameter that are either Pareto optimal or Pareto
inefficient in the quantum strategic spaces. It is shown that the Eisert et al
miracle move is a special move that leads always to distinguishable results
compare to other moves. We show that the dilemma like situation is resolved in
favor of one player or the other.Comment: 14 pages and 6 figure
Testing Semi-strong Form Efficiency of Stock Market
The efficient market hypothesis suggests that stock markets are âinformationally efficientâ. That is, any new information relevant to the market is spontaneously reflected in the stock prices. A consequence of this hypothesis is that past prices cannot have any predictive power for future prices once the current prices have been used as an explanatory variable. In other words the change in future prices depends only on arrival of new information that was unpredictable today hence it is based on surprise information. Another consequence of this hypothesis is that arbitrage opportunities are wiped out instantaneously. Empirical tests of the efficient market hypothesis actually test for these consequences in various ways. Some of them have been summarised in earlier chapters. These tests generally could not conclusively accept the random-walk hypothesis of stock returns even when GARCH effects were accounted for. Many studies have found empirical regularities that are contrary to the efficient market hypothesis. For example, the monthly, weekly and daily returns on stocks tend to exhibit discernable patterns, such as seasonal affects, month of the year affect, day of the week affect, hourly affect etc. In case of Pakistanâs stock markets too such affects are identified. Such as the Ramadan affect [see Hussain and Uppal (1999)], seasonal effects and day of the week affect. Further, the wide spread use of âtechnical analysisâ among stock traders and their ability to predict to some extent the direction of movements in the prices of individual stocks over medium term testifies to the existence of patterns and seasonal trends.
Evaluation of wear of contemporary flowable resin composites: an in vitro study
OBJECTIVES: Dental wear is considered one of the reasons for composite restorations failure. Several clinical problems may arise as result of uncontrolled wear process, including compromising masticatory function, poor aesthetics, loss of interocclusal space, teeth pain and sensitivity, and tempromandibular problems. Newly released flowable composites have been introduced to the market, that are indicated for occlusal class I and II cavity restorations. The purposes of this study are (1) to evaluate the wear resistance of newly released flowable composites against two antagonists, and compare them to universal packable composite, (2) to compare the wear properties of the two different types of antagonists, (3) to evaluate mechanical and esthetic properties, including microhardness, gloss, and surface roughness, of all resin composites and correlate it to wear characteristics of the materials.
MATERIALS AND METHODS: (1) Five flowable composites were used in this study: 1. Filtek Supreme Ultra Flow (3M ESPE), 2. NovaPro Flow (Nanova Biomaterials), 3. SureFil SDR Flow (Dentsply), 4. Clearfil Majesty Flow (Kuraray), and 5. G-aenial Universal Flo (GC). One universal resin composite (Filtek Supreme Ultra Universal) was used as control group. 16 Specimens were prepared from each composite by injecting into aluminum molds, then divided into two groups for two types of antagonists (n=8). The first antagonist from natural enamel cusps, the other type was from feldspar ceramic block, Vitabloc Mark II. Both were standardized and polished. After mounting the antagonists in the wear-testing machine, a uniform sliding abrasion was applied up to 200k sliding cycles. Then the measurement of dry weight, wear depth and surface roughness of the specimens and the antagonist cusps were conducted at 3 different intervals, baseline, 100k, and 200k cycles. The amount of wear was determined by measuring the weight loss and calculating volume loss. One representative sample was randomly selected from each group for scanning electron microscope examination of the surface morphology.
(2) 3 samples were prepared from each resin composite material for the microhardness and gloss test. The composite specimens were finishing and polishing by Buehler grinding-polishing system for four minutes each, then rinsed and ultrasonically cleaned in distilled water for 4 minutes. The surface gloss test was performed by using Novo Curve glossmeter. Five gloss readings were taken from each specimen at different locations, and the mean value was calculated and recorded as the GU reading of each specimen. The Knoopâs microhardness was measured on a MICROMET 2003 microhardness tester. Five indentations at different locations with at least 100 ÎŒm apart were performed on each specimen. The five readings were averaged to produce a single hardness value for each specimen.
RESULTS: (1) In general, statistical analysis revealed a significantly higher surface roughness and higher weight loss of all resin composites when opposed by ceramic antagonists compared to the samples opposed by enamel antagonists. Among the tested resin composites, there were significant differences in regards to specimen wear depth, weight loss, volume loss, and surface roughness, regardless of the antagonist type used. Both Filtek supreme universal and Filtek supreme ultra flow groups showed significantly deeper wear compared to the other flowable materials, regardless of the antagonist type used. Moreover, there were statistically significant differences in antagonistâs weight and height loss between the groups. The control group universal composite caused significantly higher weight and height loss of both antagonists.
(2) The microhardness and gloss results demonstrated statistical significant differences between all the composite materials. Clearfil Majesty Flow and Filtek Supreme Universal groups exhibited a significantly higher surface gloss compared to the other materials with the exception of the Filtek Supreme Ultra Flow group. Filtek Supreme Universal group exhibited a significantly higher Knoopâs hardness compared to the other materials.
CONCLUSIONS: Despite the limitation of this study, less weight loss and surface roughness of the flowable composites were shown when opposed by dental enamel antagonists. A significantly deeper wear was noticed on both Filtek supreme universal and flowable composites when opposed by ceramic antagonists, indicating the detrimental effect of the Feldspathic ceramic on the nanohybrid composites compared to the other nanofilled flowable composites used in the study
Testing Semi-strong Form Efficiency of Stock Market
The efficient market hypothesis suggests that stock markets
are âinformationally efficientâ. That is, any new information relevant
to the market is spontaneously reflected in the stock prices. A
consequence of this hypothesis is that past prices cannot have any
predictive power for future prices once the current prices have been
used as an explanatory variable. In other words the change in future
prices depends only on arrival of new information that was unpredictable
today hence it is based on surprise information. Another consequence of
this hypothesis is that arbitrage opportunities are wiped out
instantaneously. Empirical tests of the efficient market hypothesis
actually test for these consequences in various ways. Some of them have
been summarised in earlier chapters. These tests generally could not
conclusively accept the random-walk hypothesis of stock returns even
when GARCH effects were accounted for. Many studies have found empirical
regularities that are contrary to the efficient market hypothesis. For
example, the monthly, weekly and daily returns on stocks tend to exhibit
discernable patterns, such as seasonal affects, month of the year
affect, day of the week affect, hourly affect etc. In case of Pakistanâs
stock markets too such affects are identified. Such as the Ramadan
affect [see Hussain and Uppal (1999)], seasonal effects and day of the
week affect. Further, the wide spread use of âtechnical analysisâ among
stock traders and their ability to predict to some extent the direction
of movements in the prices of individual stocks over medium term
testifies to the existence of patterns and seasonal trends
Journal of Taibah University Medical Sciences: Ten years of existence and our special issue about innovations in medical education
Waldenstrom\u27s macroglobulinemia terminating in acute myeloid leukemia
Waldenstrom\u27s macroglobulinemia (WM) is a rare condition, accounting for approximately 2% of haematologic malignancies. The most common causes of death in these patients are progression of the malignant lymphoproliferative process, infection and cardiac failure. Acute leukemia is a rare event in the clinical course of WM. A number of case reports have documented the development of terminal acute leukemia in patients with WM following prolonged chemotherapy
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