815 research outputs found
Linear complexity over F_q and over F_{q^m} for linear recurring sequences
Since the \F_q-linear spaces \F_q^m and \F_{q^m} are isomorphic, an -fold multisequence
over the finite field \F_q with a given characteristic polynomial f \in \F_q[x], can be identified
with a single sequence over \F_{q^m} with characteristic polynomial .
The linear complexity of , which we call the generalized joint linear complexity of
, can be significantly smaller than the conventional joint linear complexity of
. We determine the expected value and the variance of the generalized joint linear complexity of
a random -fold multisequence with given minimal polynomial. The result on the expected
value generalizes a previous result on periodic -fold multisequences. Finally we determine the expected
drop of linear complexity of a random -fold multisequence with given characteristic polynomial ,
when one switches from conventional joint linear complexity to generalized joint linear complexity
Generalized joint linear complexity of linear recurring multisequences
The joint linear complexity of multisequences is an important security measure for vectorized stream cipher systems.
Extensive research has been carried out on the joint linear complexity of -periodic multisequences using tools from
Discrete Fourier transform. Each -periodic multisequence can be identified with a single -periodic sequence
over an appropriate extension field. It has been demonstrated that the linear complexity of this sequence, the so called
generalized joint linear complexity of the multisequence, may be considerably smaller than the joint linear complexity, which is not desirable for vectorized stream ciphers.
Recently new methods have been developed and results of greater generality on the joint linear complexity of
multisequences consisting of linear recurring sequences have been obtained. In this paper, using these new methods, we investigate
the relations between the generalized joint linear complexity and the joint linear complexity of
multisequences consisting of linear recurring sequences
Polycyclic codes over Galois rings with applications to repeated-root constacyclic codes
Cyclic, negacyclic and constacyclic codes are part of a larger class of codes
called polycyclic codes; namely, those codes which can be viewed as ideals of a
factor ring of a polynomial ring. The structure of the ambient ring of
polycyclic codes over GR(p^a,m) and generating sets for its ideals are
considered. Along with some structure details of the ambient ring, the
existance of a certain type of generating set for an ideal is proven.Comment: arXiv admin note: text overlap with arXiv:0906.400
Information flow and optimization in transcriptional control
In the simplest view of transcriptional regulation, the expression of a gene
is turned on or off by changes in the concentration of a transcription factor
(TF). We use recent data on noise levels in gene expression to show that it
should be possible to transmit much more than just one regulatory bit.
Realizing this optimal information capacity would require that the dynamic
range of TF concentrations used by the cell, the input/output relation of the
regulatory module, and the noise levels of binding and transcription satisfy
certain matching relations. This parameter-free prediction is in good agreement
with recent experiments on the Bicoid/Hunchback system in the early Drosophila
embryo, and this system achieves ~90% of its theoretical maximum information
transmission.Comment: 5 pages, 4 figure
Acute Effects of Vardenafil on Pulmonary Artery Responsiveness in Pulmonary Hypertension
Phosphodiesterase type-5 (PDE-5) inhibitors are novel and important options for the treatment of pulmonary arterial hypertension (PAH). Therefore, we aimed to examine effects of vardenafil, a PDE-5 inhibitor, on the pulmonary arteries isolated from rats with monocrotaline- (MCT-) induced pulmonary hypertension. MCT (60 mg/kg) or its vehicle was administered by a single intraperitoneal injection to 6-week-old male Sprague Dawley rats. Rats were sacrificed 21 days after MCT injection, and the main pulmonary arteries were isolated and then mounted in 20 mL organ baths. Concentration-response curves for vardenafil (10−10–10−5 M) were constructed in phenylephrine- (Phe-) precontracted rings. PAH caused marked rightward shift in the curves to vardenafil whereas maximal responses were not affected. Inhibition of NO synthase (L-NAME, 10−4 M) or guanylyl cyclase (ODQ, 10−5 M) caused similar attenuation in responses evoked by vardenafil. Moreover, contraction responses induced by CaCl2 (3×10−5–3×10−2 M) were significantly reduced in concentration-dependent manner by vardenafil. In conclusion, vardenafil induced pulmonary vasodilatation via inhibition of extracellular calcium entry in addition to NO-cGMP pathway activation. These results provide evidence that impaired arterial relaxation in PAH can be prevented by vardenafil. Thus, vardenafil represents a valuable therapeutic approach in PAH besides other PDE-5 inhibitors
Are 25(OH) D concentrations associated with asthma control and pulmonary function test?
Background: The relationship between vitamin D and asthma is still under investigation. We aimed to evaluate the association between serum vitamin D levels and clinical characteristics of asthma, and the impact of vitamin D deficiency on the clinical manifestations, as them being the issues of debate. Methods: Patients who were admitted to the outpatient clinics of Chest Diseases Department of Akdeniz University Hospital between January 2014 and December 2014, have been diagnosed as asthma according to the GINA 2014 guidelines were included in this study. Subjects with COPD, bronchiectasis, pneumonia or tuberculosis were excluded. Asthma exacerbation was defined, according to the GINA guidelines, as episodes of progressive shortness of breath, cough, wheezing or chest tightness accompanied by PFT abnormalities such as decreased PEF or FEV1. Results: A total of 158 patients with mean age of 48.8 years were included in the study. Twenty-seven (17.08) of the patients demonstrated sufficient vitamin D serum levels (i.e. ≥30 ng/mL), while the remaining 131 (82.92) patients had vitamin D insufficiency (i.e. <30 ng/mL). When these two patient groups (vitamin D sufficient vs. insufficient) were compared with each other, the patients showing sufficient levels of vitamin D were found to reveal significantly higher FEV1 (L) and FVC (L) values. When the patients were grouped into 4 categories with regard to their serum vitamin D measurements, hospitalization numbers were found to significantly increase with decreasing vitamin D levels. Conclusion: Vitamin D deficiency was significantly associated with poorer pulmonary functions and higher hospitalization numbers
A stochastic spectral analysis of transcriptional regulatory cascades
The past decade has seen great advances in our understanding of the role of
noise in gene regulation and the physical limits to signaling in biological
networks. Here we introduce the spectral method for computation of the joint
probability distribution over all species in a biological network. The spectral
method exploits the natural eigenfunctions of the master equation of
birth-death processes to solve for the joint distribution of modules within the
network, which then inform each other and facilitate calculation of the entire
joint distribution. We illustrate the method on a ubiquitous case in nature:
linear regulatory cascades. The efficiency of the method makes possible
numerical optimization of the input and regulatory parameters, revealing design
properties of, e.g., the most informative cascades. We find, for threshold
regulation, that a cascade of strong regulations converts a unimodal input to a
bimodal output, that multimodal inputs are no more informative than bimodal
inputs, and that a chain of up-regulations outperforms a chain of
down-regulations. We anticipate that this numerical approach may be useful for
modeling noise in a variety of small network topologies in biology
Benefits of omalizumab on anxiety and depression in patients with severe asthma
Background: Asthma is one of the most common chronic diseases and may cause psychiatric disorders affecting the patients’ quality of life. In our study, we evaluated the effect of omalizumab treatment on anxiety disorder and depression using Beck Depression Scale (BDS) and State Trait Anxiety Inventory (STAI).
Methods: Anxiety level was determined with STAI, whereas depression level was evaluated by BDS. Patients were asked to mark the questionnaires to reflect their emotional state before treatment, and to reflect their emotions they are feeding in the current moment. All patients receiving omalizumab treatment were included in the study. Patients with known neuropsychiatric disorder were excluded from the study.
Results: A total of 20 patients with mean age of 50.25 years were enrolled in the study. Gender distribution was: 5(25%) male patients and 15(75%) female patients. All patients with severe asthma received omalizumab treatment. The omalizumab treatment period was shown for mean 17.6 months (2-40 months). In anxiety scales, there was statistically significant difference compared with pretreatment and posttreatment periods. Depression (moderate to severe) was present in 12 patients before omalizumab treatment and 3 patients after omalizumab treatment.
Conclusions: Uncontrolled asthma as a chronic disorder can cause depressive symptoms and worsen quality of life. We believe by controlling asthma, quality of life will improvein such patients. In appropriate indication, omalizumab can improve depression and anxiety in asthma patients
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