652 research outputs found
Liver Transplantation for Budd-Chiari Syndrome
Orthotopic liver transplantation was accomplished in a 22-year-old woman dying of the Budd-Chiari syndrome. She is well and has normal liver function 16 months postoperatively. In view of the good early result, it will be appropriate to consider liver replacement for this disease in further well-selected cases. © 1976, American Medical Association. All rights reserved
Freak observers and the measure of the multiverse
I suggest that the factor in the pocket-based measure of the
multiverse, , should be interpreted as accounting for equilibrium
de Sitter vacuum fluctuations, while the selection factor accounts for
the number of observers that were formed due to non-equilibrium processes
resulting from such fluctuations. I show that this formulation does not suffer
from the problem of freak observers (also known as Boltzmann brains).Comment: 6 pages, no figures; references adde
Rationale for UV-filtered clover fermions
We study the contributions Sigma_0 and Sigma_1, proportional to a^0 and a^1,
to the fermion self-energy in Wilson's formulation of lattice QCD with
UV-filtering in the fermion action. We derive results for m_{crit} and the
renormalization factors Z_S, Z_P, Z_V, Z_A to 1-loop order in perturbation
theory for several filtering recipes (APE, HYP, EXP, HEX), both with and
without a clover term. The perturbative series is much better behaved with
filtering, in particular tadpole resummation proves irrelevant. Our
non-perturbative data for m_{crit} and Z_A/(Z_m*Z_P) show that the combination
of filtering and clover improvement efficiently reduces the amount of chiral
symmetry breaking -- we find residual masses am_{res}=O(10^{-2}).Comment: 25 pages, 4 figures; v2: typo in eqn. (37) fixed [agrees with
published version
The association of cognitive impairment with gray matter atrophy and cortical lesion load in clinically isolated syndrome
Background Multiple sclerosis can impair cognition from the early stages and has been shown to be associated with gray matter damage in addition to white matter pathology. Objectives To investigate the profile of cognitive impairment in clinically isolated syndrome (CIS), and the contribution of cortical inflammation, cortical and deep gray matter atrophy, and white matter lesions to cognitive decline. Methods Thirty patients with clinically isolated syndrome and twenty demographically- matched healthy controls underwent neuropsychologic assessment through the Rao Brief Repeatable Battery, and brain magnetic resonance imaging with double inversion recovery using a 3T scanner. Results Patients with clinically isolated syndrome performed significantly worse than healthy controls on tests that evaluated verbal memory, visuospatial learning and memory, and verbal fluency. Significant deep gray matter atrophy was found in the patients but cortical volume was not lower than the controls. Visual memory tests correlated with the volume of the hippocampus, cerebral white matter and deep gray matter structures and with cerebellar cortical atrophy. Cortical or white matter lesion load did not affect cognitive test results. Conclusion In our patients with CIS, it was shown that cognitive impairment was mainly related to cerebral white matter, cerebellar cortical and deep gray matter atrophy, but not with cortical inflammation, at least in the early stage of disease. © 2016 Elsevier B.V
The Effectiveness of Blended Learning Approach with Student’s Perceptions in Control Systems Engineering Course
This paper presents student’s perception and the effectiveness of blended learning in the control system engineering course. A sample size of 64 engineering students was selected to participate in this research works as a part of the third year engineering programme. Instead of a common face-to-face learning delivery approach, a blended learning approach is used in the evaluation process. Students responded to Likert-type surveys using the research instrument where the questionnaire that utilized to collect the research data contained three sections. Section one is conducted to identify general student’s demographic such as age, highest academic qualification and gender while section two consists of evaluation of the experiential data such internet experience, student technology access and proficiency status as factors that may influence student’s behaviour. Finally, section three in the instrument is performed to evaluate the student’s perception with blended learning that measured using the questionnaire item. Students expressed their response regarding the instrument item on a five-point scale from “Strongly Disagree” to “Strongly Agree”. Then, the effectiveness of blended learning in the engineering course in comparison with the traditional teaching approach is assessed with the ultimate goal of this approach is to develop and promote critical thinking where students will be able to learn through meaningful activities. The results of this research works support the expectation that blended learning approach offers meaningful learning and effective towards improving the student’s performance. As conclusion, the study showed that blended learning might potentially increase student’s motivation leading to better performance in the engineering education
The passage of time in Iraq during the covid-19 pandemic
The covid-19 global pandemic has influenced the day-to-day lives of people across the world. One consequence of this has been significant distortion to the subjective speed at which people feel like time is passing. To date, temporal distortions during covid-19 have mainly been studied in Europe. The current study therefore sought to explore experiences of the passage of time in Iraq. An online questionnaire was used to explore the passage of time during the day, week and the 11 months since the first period of covid-19 restrictions were imposed in Iraq. The questionnaire also measured affective and demographic factors, and task-load. The results showed that distortions to the passage of time were widespread in Iraq. Participants consistently reported a slowing of the passage of time for the day and the week during the pandemic in comparison to normal (i.e. before the pandemic). Participants also reported that it felt like longer than 11-months since the first lockdown began. The passage of time during the day and week were not predicted by any demographic, affective or task-load measures taken in the study. The perceived length of time since the first lockdown was however predicted by stress and change of life due to covid, with greater stress and greater change of life being associated with greater subjective lengthening of the pandemic. The findings indicate that whilst distortions to the passage of time during covid-19 appear to be a global phenomenon, the factors which predict temporal experience during the pandemic differ between countries and cultures
Noncommutative Inspired Black Holes in Extra Dimensions
In a recent string theory motivated paper, Nicolini, Smailagic and Spallucci
(NSS) presented an interesting model for a noncommutative inspired,
Schwarzschild-like black hole solution in 4-dimensions. The essential effect of
having noncommutative co-ordinates in this approach is to smear out matter
distributions on a scale associated with the turn-on of noncommutativity which
was taken to be near the 4-d Planck mass. In particular, NSS took this smearing
to be essentially Gaussian. This energy scale is sufficiently large that in 4-d
such effects may remain invisible indefinitely. Extra dimensional models which
attempt to address the gauge hierarchy problem, however, allow for the
possibility that the effective fundamental scale may not be far from 1
TeV, an energy regime that will soon be probed by experiments at both the LHC
and ILC. In this paper we generalize the NSS model to the case where flat,
toroidally compactified extra dimensions are accessible at the Terascale and
examine the resulting modifications in black hole properties due to the
existence of noncommutativity. We show that while many of the
noncommutativity-induced black hole features found in 4-d by NSS persist, in
some cases there can be significant modifications due the presence of extra
dimensions. We also demonstrate that the essential features of this approach
are not particularly sensitive to the Gaussian nature of the smearing employed
by NSS.Comment: 30 pages, 12 figures; slight text modifications and references adde
R Symmetries in the Landscape
In the landscape, states with symmetries at the classical level form a
distinct branch, with a potentially interesting phenomenology. Some preliminary
analyses suggested that the population of these states would be significantly
suppressed. We survey orientifolds of IIB theories compactified on Calabi-Yau
spaces based on vanishing polynomials in weighted projective spaces, and find
that the suppression is quite substantial. On the other hand, we find that a
R-parity is a common feature in the landscape. We discuss whether the
cosmological constant and proton decay or cosmology might select the low energy
branch. We include also some remarks on split supersymmetry.Comment: 13 page
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