3,798 research outputs found
Mitochondrial disease in Southwestern Finland. Population-based molecular genetic and clinical studies
Mitochondria are present in all eukaryotic cells. They enable these cells utilize oxygen
in the production of adenosine triphosphate in the oxidative phosphorylation system,
the mitochondrial respiratory chain. The concept ‘mitochondrial disease’ conventionally
refers to disorders of the respiratory chain that lead to oxidative phosphorylation defect.
Mitochondrial disease in humans can present at any age, and practically in any organ
system. Mitochondrial disease can be inherited in maternal, autosomal dominant,
autosomal recessive, or X-chromosomal fashion. One of the most common molecular
etiologies of mitochondrial disease in population is the m.3243A>G mutation in the
MT-TL1 gene, encoding mitochondrial tRNALeu(UUR). Clinical evaluation of patients
with m.3243A>G has revealed various typical clinical features, such as stroke-like
episodes, diabetes mellitus and sensorineural hearing loss. The prevalence and clinical
characteristics of mitochondrial disease in population are not well known. This
thesis consists of a series of studies, in which the prevalence and characteristics of
mitochondrial disease in the adult population of Southwestern Finland were assessed.
Mitochondrial haplogroup Uk was associated with increased risk of occipital ischemic
stroke among young women. Large-scale mitochondrial DNA deletions and mutations
of the POLG1 gene were the most common molecular etiologies of progressive external
ophthalmoplegia. Around 1% of diabetes mellitus emerging between the ages 18 – 45
years was associated with the m.3243A>G mutation. Moreover, among these young
diabetic patients, mitochondrial haplogroup U was associated with maternal family
history of diabetes. These studies demonstrate the usefulness of carefully planned
molecular epidemiological investigations in the study of mitochondrial disorders.Siirretty Doriast
Quantum key distribution with realistic states: photon-number statistics in the photon-number splitting attack
Quantum key distribution can be performed with practical signal sources such
as weak coherent pulses. One example of such a scheme is the Bennett-Brassard
protocol that can be implemented via polarization of the signals, or equivalent
signals. It turns out that the most powerful tool at the disposition of an
eavesdropper is the photon-number splitting attack. We show that this attack
can be extended in the relevant parameter regime such as to preserve the
Poissonian photon number distribution of the combination of the signal source
and the lossy channel.Comment: 4 page
Mixing and condensation in a wet granular medium
We have studied the effect of small amounts of added liquid on the dynamic
behavior of a granular system consisting of a mixture of glass beads of two
different sizes. Segregation of the large beads to the top of the sample is
found to depend in a nontrivial way on the liquid content. A transition to
viscoplastic behavior occurs at a critical liquid content, which depends upon
the bead size. We show that this transition can be interpreted as a
condensation due to the hysteretic liquid bridge forces connecting the beads,
and provide the corresponding phase diagram.Comment: submitted to PR
Mufasa: The assembly of the red sequence
We examine the growth and evolution of quenched galaxies in the Mufasa cosmo-
logical hydrodynamic simulations that include an evolving halo mass-based quench-
ing prescription, with galaxy colours computed accounting for line-of-sight extinc-
tion to individual star particles. Mufasa reproduces the observed present-day red
sequence quite well, including its slope, amplitude, and scatter. In Mufasa, the red
sequence slope is driven entirely by the steep stellar mass{stellar metallicity relation,
which independently agrees with observations. High-mass star-forming galaxies blend
smoothly onto the red sequence, indicating the lack of a well-de ned green valley at
M & 1010:5M . The most massive galaxies quench the earliest and then grow very
little in mass via dry merging; they attain their high masses at earlier epochs when
cold in
ows more e ectively penetrate hot halos. To higher redshifts, the red sequence
becomes increasingly contaminated with massive dusty star-forming galaxies; UVJ
selection subtly but e ectively separates these populations. We then examine the evo-
lution of the mass functions of central and satellite galaxies split into passive and
star-forming via UVJ. Massive quenched systems show good agreement with obser-
vations out to z 2, despite not including a rapid early quenching mode associated
with mergers. However, low-mass quenched galaxies are far too numerous at z . 1 in
Mufasa, indicating that Mufasa strongly over-quenches satellites. A challenge for
hydrodynamic simulations is to devise a quenching model that produces enough early
massive quenched galaxies and keeps them quenched to z = 0, while not being so
strong as to over-quench satellites; Mufasa only succeeds at the former.IS
Polish version of the Intermittent Claudication Questionnaire
Introduction. The assessment of health-related quality of life includes the assessment of physical condition and motor skills, mental condition, social and economic situation, and somatic experiences. The specific ques-tionnaires used in patients with intermittent claudication include i.a. Peripheral Artery Questionnaire, Vascular Quality of Life Questionnaire, PAD Quality of Life Questionnaire, and Walking Impairment Questionnaire, which is the only one of the aforementioned questionnaires that is available in Polish. The Intermittent Claudication Questionnaire (ICQ) available in English is a specific instrument for assessing the quality of life of patients with intermittent claudication. This paper attempts at evaluating the reliability of the Polish version of ICQ.
Material and methods. The process of validation of the Polish version of the questionnaire involved translating the questionnaire and evaluating the newly translated tool in order to compare the results on international level for the possibility of its practical use for assessment of health-related quality of life in patients with intermittent claudication in Poland. In order to evaluate the reliability and coherence of the questionnaire, the methods of internal consistency in Cronbach’s a, as well as the intraclass correlation coefficient were applied for specific questions and for the final result of the questionnaire.
Results. The Cronbach’s a as the questionnaire’s reliability index was 0.915. Intraclass correlation calculated for the total score of the questionnaire’s answers was 0.97.
Conclusions. The Polish version of the Intermittent Claudication Questionnaire is a repeatable and reliable research tool for assessing the health-related quality of life in patients with intermittent claudication
Operator-sum representation of time-dependent density operators and its applications
We show that any arbitrary time-dependent density operator of an open system
can always be described in terms of an operator-sum representation regardless
of its initial condition and the path of its evolution in the state space, and
we provide a general expression of Kraus operators for arbitrary time-dependent
density operator of an -dimensional system. Moreover, applications of our
result are illustrated through several examples.Comment: 4 pages, no figure, brief repor
Unambiguous state discrimination in quantum cryptography with weak coherent states
The use of linearly independent signal states in realistic implementations of
quantum key distribution (QKD) enables an eavesdropper to perform unambiguous
state discrimination. We explore quantitatively the limits for secure QKD
imposed by this fact taking into account that the receiver can monitor to some
extend the photon number statistics of the signals even with todays standard
detection schemes. We compare our attack to the beamsplitting attack and show
that security against beamsplitting attack does not necessarily imply security
against the attack considered here.Comment: 10 pages, 6 figures, updated version with added discussion of
beamsplitting attac
Towards a complexity theory for the congested clique
The congested clique model of distributed computing has been receiving
attention as a model for densely connected distributed systems. While there has
been significant progress on the side of upper bounds, we have very little in
terms of lower bounds for the congested clique; indeed, it is now know that
proving explicit congested clique lower bounds is as difficult as proving
circuit lower bounds.
In this work, we use various more traditional complexity-theoretic tools to
build a clearer picture of the complexity landscape of the congested clique:
-- Nondeterminism and beyond: We introduce the nondeterministic congested
clique model (analogous to NP) and show that there is a natural canonical
problem family that captures all problems solvable in constant time with
nondeterministic algorithms. We further generalise these notions by introducing
the constant-round decision hierarchy (analogous to the polynomial hierarchy).
-- Non-constructive lower bounds: We lift the prior non-uniform counting
arguments to a general technique for proving non-constructive uniform lower
bounds for the congested clique. In particular, we prove a time hierarchy
theorem for the congested clique, showing that there are decision problems of
essentially all complexities, both in the deterministic and nondeterministic
settings.
-- Fine-grained complexity: We map out relationships between various natural
problems in the congested clique model, arguing that a reduction-based
complexity theory currently gives us a fairly good picture of the complexity
landscape of the congested clique
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