384 research outputs found
Counter Machines and Distributed Automata: A Story about Exchanging Space and Time
We prove the equivalence of two classes of counter machines and one class of
distributed automata. Our counter machines operate on finite words, which they
read from left to right while incrementing or decrementing a fixed number of
counters. The two classes differ in the extra features they offer: one allows
to copy counter values, whereas the other allows to compute copyless sums of
counters. Our distributed automata, on the other hand, operate on directed path
graphs that represent words. All nodes of a path synchronously execute the same
finite-state machine, whose state diagram must be acyclic except for
self-loops, and each node receives as input the state of its direct
predecessor. These devices form a subclass of linear-time one-way cellular
automata.Comment: 15 pages (+ 13 pages of appendices), 5 figures; To appear in the
proceedings of AUTOMATA 2018
Enzymfreisetzung und Aktivierung der Kallikrein-Kinin-Systeme bei experimenteller Pankreatitis
Das klinische Bild der akuten Pankreatitis wird entscheidend durch die sekundĂ€re SchĂ€digung von Herz-Kreislauf-System, Lunge und Niere bestimmt. Ziel der vorliegenden Untersuchung war es, durch Messungen in venösem Pankreasblut, Pankreaslymphe und Peritonealexsudat die Kompartimente zu bestimmen, ĂŒber die die systemischen SchĂ€digungen vermittelt werden. An anĂ€sthesierten Schweinen wurden die systemischen, hĂ€modynamischen Parameter durch gesteuerte Volumentherapie konstant gehalten. Die Schweine wurden randomisiert der Kontrollgruppe (n = 9) oder einer der Pankreatitisgruppen zugeteilt (jeweils n = 10). Die Pankreatitis wurde durch Infusion von freier FettsĂ€ure in die Pankreasarterien (FFS) oder durch Infusion einer 5%igen Natrium-Taurocholat-Lösung retrograd in den Pankreasgang (NaT) ausgelöst. Nach Isolation des Pankreas wurde venöses Pankreasblut, Pankreaslymphe und Peritonealexsudat gewonnen und die AktivitĂ€t von Lipase, Phospholipase A und Plasmaprokallikrein sowie die Konzentration von Organkallikrein und Kininogen bestimmt. In beiden Pankreatitismodellen fand sich ein Anstieg der EnzymaktivitĂ€ten. Die höchsten AktivitĂ€ten fanden sich im Peritonealexsudat (Phospholipase A nach 40 min: Kontrolle 10,0 U/1, NaT 72,2 U/1). In beiden Pankreatitismodellen fanden sich auĂerdem Hinweise fĂŒr eine Aktivierung des Organkallikrein-Kinin-Systems durch den Anstieg der Organkallikreinkonzentration und den Abfall der Gesamtkininogenkonzentration. Die stĂ€rksten VerĂ€nderungen fanden sich wieder im Peritonealexsudat (Organkallikrein nach 40 min: Kontrolle 14,7 ng/ml, NaT 452 ng/ml).The clinical course of acute pancreatitis is strongly influenced by secondary cardiac, pulmonary and renal damage. The aim of the present study was to gather information about the compartment promoting the systemic damage. Therefore the activity of lipase, phospholipase A and plasmaprokallikrein and the concentration of tissue kallikrein and kininogen were measured in portal venous blood, pancreatic lymph and peritoneal exudate. Anaesthetized pigs were subjected to fluid resuscitation to keep systemic haemodynamic parameters constant. The pancreas was isolated in situ. The pigs were randomly assigned to a control group (n = 9) or one of the two pancreatitis groups (n = 10 each). Pancreatitis was induced by i.a. infusion of free fatty acid (FFS) or retrograde infusion of 5 % sodium taurocholate intraductally (NaT). In both pancreatitis groups the activity of lipase and phospholipase A increased. The most pronounced changes were seen in the peritoneal exsudate (phospholipase A activity 40 min after induction: control 10.0 U/1, NaT 72.2 U/1). In both pancreatitis groups there was evidence for activation of the tissue kallikreinkinin system in the form of an increase in the kallikrein concentration and a decrease in the kininogen concentration. Again the changes were most pronounced in the peritoneal exsudate (tissue kallikrein 40 min after induction: control 14.7 ng/ml, NaT 452 ng/ml)
Self-Organized States in Cellular Automata: Exact Solution
The spatial structure, fluctuations as well as all state probabilities of
self-organized (steady) states of cellular automata can be found (almost)
exactly and {\em explicitly} from their Markovian dynamics. The method is shown
on an example of a natural sand pile model with a gradient threshold.Comment: 4 pages (REVTeX), incl. 2 figures (PostScript
Alteration of T cell cytokine production in PLPp-139-151-induced EAE in SJL mice by an immunostimulatory CpG Oligonucleotide
Experimental autoimmune encephalomyelitis (EAE) is - in certain aspects - regarded as an animal model of the human CNS autoimmune disease multiple sclerosis (MS). While in EAE CNS-autoantigen-specific immunity is induced in a defined way, the initial processes leading to CNS autoimmunity in humans are so far unknown. Despite essential restrictions, which exist regarding the interpretation of EAE data towards MS, EAE might be a useful model to study certain basic aspects of CNS autoimmunity. Studies in MS have demonstrated that established autoimmune pathology can be critically influenced by environmental factors, in particular viral and bacterial infections. To investigate this interaction, EAE as an instrument to study CNS autoimmunity under defined conditions appears to be a suitable experimental tool. For this reason, we here investigated the influence of the Toll-like-receptor (TLR) ligand CpG oligonucleotide (CpG) on already established CNS autoimmunity in murine proteolipid protein (PLP)-induced EAE in SJL mice. CpG were found to co-stimulate PLPp-specific IFN-Îł production in the peripheral immune system and in the CNS. However, CpG induced Interleukin (IL)-17 production in the inflamed CNS both alone and in combination with additional PLPp stimulation. These findings might indicate a mechanism by which systemic infections and the microbial stimuli associated with them may influence already existing CNS autoimmune pathology
Exact Solution of an Evolutionary Model without Ageing
We introduce an age-structured asexual population model containing all the
relevant features of evolutionary ageing theories. Beneficial as well as
deleterious mutations, heredity and arbitrary fecundity are present and managed
by natural selection. An exact solution without ageing is found. We show that
fertility is associated with generalized forms of the Fibonacci sequence, while
mutations and natural selection are merged into an integral equation which is
solved by Fourier series. Average survival probabilities and Malthusian growth
exponents are calculated indicating that the system may exhibit mutational
meltdown. The relevance of the model in the context of fissile reproduction
groups as many protozoa and coelenterates is discussed.Comment: LaTeX file, 15 pages, 2 ps figures, to appear in Phys. Rev.
Velocity and density profiles of granular flow in channels using lattice gas automaton
We have performed two-dimensional lattice-gas-automaton simulations of
granular flow between two parallel planes. We find that the velocity profiles
have non-parabolic distributions while simultaneously the density profiles are
non-uniform. Under non-slip boundary conditions, deviation of velocity profiles
from the parabolic form of newtonian fluids is found to be characterized solely
by ratio of maximal velocity at the center to the average velocity, though the
ratio depends on the model parameters in a complex manner. We also find that
the maximal velocity () at the center is a linear function of the
driving force (g) as with non-zero in
contrast with newtonian fluids. Regarding density profiles, we observe that
densities near the boundaries are higher than those in the center. The width of
higher densities (above the average density) relative to the channel width is a
decreasing function of a variable which scales with the driving force (g),
energy dissipation parameter () and the width of the system (L) as
with exponents and . A phenomenological theory based on a scaling argument is presented to
interpret these findings.Comment: Latex, 15 figures, to appear in PR
Epileptic networks in focal cortical dysplasia revealed using electroencephalography-functional magnetic resonance imaging.
Surgical treatment of focal epilepsy in patients with focal cortical dysplasia (FCD) is most successful if all epileptogenic tissue is resected. This may not be evident on structural magnetic resonance imaging (MRI), so intracranial electroencephalography (icEEG) is needed to delineate the seizure onset zone (SOZ). EEG-functional MRI (fMRI) can reveal interictal discharge (IED)-related hemodynamic changes in the irritative zone (IZ). We assessed the value of EEG-fMRI in patients with FCD-associated focal epilepsy by examining the relationship between IED-related hemodynamic changes, icEEG findings, and postoperative outcome
Enzymfreisetzung und Aktivierung der Kallikrein-Kinin-Systeme bei experimenteller Pankreatitis
Das klinische Bild der akuten Pankreatitis wird entscheidend durch die sekundĂ€re SchĂ€digung von Herz-Kreislauf-System, Lunge und Niere bestimmt. Ziel der vorliegenden Untersuchung war es, durch Messungen in venösem Pankreasblut, Pankreaslymphe und Peritonealexsudat die Kompartimente zu bestimmen, ĂŒber die die systemischen SchĂ€digungen vermittelt werden. An anĂ€sthesierten Schweinen wurden die systemischen, hĂ€modynamischen Parameter durch gesteuerte Volumentherapie konstant gehalten. Die Schweine wurden randomisiert der Kontrollgruppe (n = 9) oder einer der Pankreatitisgruppen zugeteilt (jeweils n = 10). Die Pankreatitis wurde durch Infusion von freier FettsĂ€ure in die Pankreasarterien (FFS) oder durch Infusion einer 5%igen Natrium-Taurocholat-Lösung retrograd in den Pankreasgang (NaT) ausgelöst. Nach Isolation des Pankreas wurde venöses Pankreasblut, Pankreaslymphe und Peritonealexsudat gewonnen und die AktivitĂ€t von Lipase, Phospholipase A und Plasmaprokallikrein sowie die Konzentration von Organkallikrein und Kininogen bestimmt. In beiden Pankreatitismodellen fand sich ein Anstieg der EnzymaktivitĂ€ten. Die höchsten AktivitĂ€ten fanden sich im Peritonealexsudat (Phospholipase A nach 40 min: Kontrolle 10,0 U/1, NaT 72,2 U/1). In beiden Pankreatitismodellen fanden sich auĂerdem Hinweise fĂŒr eine Aktivierung des Organkallikrein-Kinin-Systems durch den Anstieg der Organkallikreinkonzentration und den Abfall der Gesamtkininogenkonzentration. Die stĂ€rksten VerĂ€nderungen fanden sich wieder im Peritonealexsudat (Organkallikrein nach 40 min: Kontrolle 14,7 ng/ml, NaT 452 ng/ml).The clinical course of acute pancreatitis is strongly influenced by secondary cardiac, pulmonary and renal damage. The aim of the present study was to gather information about the compartment promoting the systemic damage. Therefore the activity of lipase, phospholipase A and plasmaprokallikrein and the concentration of tissue kallikrein and kininogen were measured in portal venous blood, pancreatic lymph and peritoneal exudate. Anaesthetized pigs were subjected to fluid resuscitation to keep systemic haemodynamic parameters constant. The pancreas was isolated in situ. The pigs were randomly assigned to a control group (n = 9) or one of the two pancreatitis groups (n = 10 each). Pancreatitis was induced by i.a. infusion of free fatty acid (FFS) or retrograde infusion of 5 % sodium taurocholate intraductally (NaT). In both pancreatitis groups the activity of lipase and phospholipase A increased. The most pronounced changes were seen in the peritoneal exsudate (phospholipase A activity 40 min after induction: control 10.0 U/1, NaT 72.2 U/1). In both pancreatitis groups there was evidence for activation of the tissue kallikreinkinin system in the form of an increase in the kallikrein concentration and a decrease in the kininogen concentration. Again the changes were most pronounced in the peritoneal exsudate (tissue kallikrein 40 min after induction: control 14.7 ng/ml, NaT 452 ng/ml)
Fuzzy Fibers: Uncertainty in dMRI Tractography
Fiber tracking based on diffusion weighted Magnetic Resonance Imaging (dMRI)
allows for noninvasive reconstruction of fiber bundles in the human brain. In
this chapter, we discuss sources of error and uncertainty in this technique,
and review strategies that afford a more reliable interpretation of the
results. This includes methods for computing and rendering probabilistic
tractograms, which estimate precision in the face of measurement noise and
artifacts. However, we also address aspects that have received less attention
so far, such as model selection, partial voluming, and the impact of
parameters, both in preprocessing and in fiber tracking itself. We conclude by
giving impulses for future research
Prescribing patterns in dementia: a multicentre observational study in a German network of CAM physicians
<p>Abstract</p> <p>Background</p> <p>Dementia is a major and increasing health problem worldwide. This study aims to investigate dementia treatment strategies among physicians specialised in complementary and alternative medicine (CAM) by analysing prescribing patterns and comparing them to current treatment guidelines in Germany.</p> <p>Methods</p> <p>Twenty-two primary care physicians in Germany participated in this prospective, multicentre observational study. Prescriptions and diagnoses were reported for each consecutive patient. Data were included if patients had at least one diagnosis of dementia according to the 10th revision of the International Classification of Diseases during the study period. Multiple logistic regression was used to determine factors associated with a prescription of any anti-dementia drug including <it>Ginkgo biloba</it>.</p> <p>Results</p> <p>During the 5-year study period (2004-2008), 577 patients with dementia were included (median age: 81 years (IQR: 74-87); 69% female). Dementia was classified as unspecified dementia (57.2%), vascular dementia (25.1%), dementia in Alzheimer's disease (10.4%), and dementia in Parkinson's disease (7.3%). The prevalence of anti-dementia drugs was 25.6%. The phytopharmaceutical <it>Ginkgo biloba </it>was the most frequently prescribed anti-dementia drug overall (67.6% of all) followed by cholinesterase inhibitors (17.6%). The adjusted odds ratio (AOR) for receiving any anti-dementia drug was greater than 1 for neurologists (AOR = 2.34; CI: 1.59-3.47), the diagnosis of Alzheimer's disease (AOR = 3.28; CI: 1.96-5.50), neuroleptic therapy (AOR = 1.87; CI: 1.22-2.88), co-morbidities hypertension (AOR = 2.03; CI: 1.41-2.90), and heart failure (AOR = 4.85; CI: 3.42-6.88). The chance for a prescription of any anti-dementia drug decreased with the diagnosis of vascular dementia (AOR = 0.64; CI: 0.43-0.95) and diabetes mellitus (AOR = 0.55; CI: 0.36-0.86). The prescription of <it>Ginkgo biloba </it>was associated with sex (female: AOR = 0.41; CI: 0.19-0.89), patient age (AOR = 1.06; CI: 1.02-1.10), treatment by a neurologist (AOR = 0.09; CI: 0.03-0.23), and the diagnosis of Alzheimer's disease (AOR = 0.07; CI: 0.04-0.16).</p> <p>Conclusions</p> <p>This study provides a comprehensive analysis of everyday practice for treatment of dementia in primary care in physicians with a focus on CAM. The prescribing frequency for anti-dementia drugs is equivalent to those found in other German studies, while the administration of <it>Ginkgo biloba </it>is significantly higher.</p
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