A covering code, or a covering, is a set of codewords such that the union of balls centered at these codewords covers the entire space. As a rule, the problem consists in finding the minimum ...cardinality of a covering code. For the classical Hamming metric, the size of the smallest covering code of a fixed radius
is known up to a constant factor. A similar result has recently been obtained for codes with
insertions and for codes with
deletions. In the present paper we study coverings of a space for the fixed length Levenshtein metric, i.e., for
insertions and
deletions. For
and
, we prove new lower and upper bounds on the minimum cardinality of a covering code, which differ by a constant factor only.
Feedback Insertion-Deletion Codes Maringer, G.; Polyanskii, N. A.; Vorobyev, I. V. ...
Problems of information transmission,
07/2021, Letnik:
57, Številka:
3
Journal Article
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A new problem of transmitting information over the adversarial insertion-deletion channel with feedback is introduced. Assume that the encoder transmits
binary symbols one by one over a channel in ...which some symbols can be deleted and some additional symbols can be inserted. After each transmission, the encoder is notified about insertions or deletions that have occurred within the previous transmission, and the encoding strategy can be adapted accordingly. The goal is to design an encoder that is able to transmit error-free as much information as possible under the assumption that the total number of deletions and insertions is limited by
,
. We show how this problem can be reduced to the problem of transmitting messages over the substitution channel. Thereby, the maximal asymptotic rate of feedback insertion-deletion codes is completely established. The maximal asymptotic rate for the adversarial substitution channel has been partially determined by Berlekamp and later completed by Zigangirov. However, the analysis of the lower bound by Zigangirov is quite complicated. We revisit Zigangirov's result and present a more elaborate version of his proof.
We address the problem of correcting a single error in an arbitrary discrete memoryless channel with error-free instantaneous feedback. For the case of a one-time feedback, we propose a method for ...constructing optimal transmission strategies. The obtained result allows us to prove that for a binary channel, two feedbacks are sufficient to transmit the same number of messages as in the case of complete feedback. We also apply the developed techniques to a binary asymmetric channel to construct transmission strategies for small lengths.
Background. Carfilzomib, lenalidomide, and dexamethasone (KRd) have been approved for the treatment of relapsed and refractory multiple myeloma (RRMM) based on ASPIRE clinical trial.
Aim. Analysis of ...efficacy and safety of KRd in routine clinical practice.
Materials and methods. The prospective analysis included patients with MM who received at least one line of previous therapy. The inclusion criteria were relapse/progression; refractoriness; lack of very good partial response (VGPR) and more after the first line of therapy. Since February 2016, we used KRd like in ASPIRE trial, since October 2019, carfilzomib has been used at a dose of 56 mg/m2 on days 1, 8 and 15. Autologous hematopoietic stem cell transplantation (autoHSCT), consolidation (KRd) and maintenance therapy (Rd) were regarded as one line of therapy.
Results and discussion. We evaluated 77 patients with median age at the time of diagnosis is 55 (3072) years. For 56% (n=43) of patients KRd was applied as the second line (group 1), for 44% (n=34) as the third and more (group 2). In 23/43 patients from group 1, an early change in therapy was made due to insufficient effectiveness (after 24 courses of VCD or PAD). KRd served as a "bridge" to autoHSCT in 25 (32%) patients (21 of 25 in group 1). Another 7 patients underwent collection of autoHSC (all from group 1).
The overall response rate (ORR) was 80.5%, with 33.8% complete response (CR) and 26% VGPR. ORR in group 1 was 98% versus 65.6% in group 2; 24-month overall survival (OS) was 70%, progression free survival (PFS) 49.8%. In group 1, 24-month OS was 85.6% versus 50.0% in group 2, 24-month PFS was 67.8% versus 25.5% (p=0.01).
Conclusion. Our analysis confirmed the high efficiency of KRd in the treatment of RRMM in real-life practice. Early correction of therapy with insufficient effectiveness of the first line made it possible to implement the strategy of high-dose consolidation and autoHSCT in a larger percentage of patients with MM.
Chromatin remodeling is an essential part of transcription initiation. We show that at heat shock gene promoters functional interactions between individual ATP-dependent chromatin remodeling ...complexes play critical role in both nucleosome displacement and Pol II recruitment. Using HSP12, HSP82 and SSA4 gene promoters as reporters, we demonstrated that while inactivation of SNF2, a critical ATPase of the SWI/SNF complex, primarily affects the HSP12 promoter, depletion of STH1- a SNF2 homolog from the RSC complex reduces histone displacement and abolishes the Pol II recruitment at all three promoters. From these results, we conclude that redundancy between SWI/SNF and RSC complexes is only partial and likely is affecting different chromatin remodeling steps. While inactivation of other individual ATP-dependent chromatin remodeling complexes negligibly affects reporter promoters, combinatorial inactivation of SNF2 and ISW1 has a synergistic effect by diminishing histone loss during heat induction and eliminating Pol II recruitment. Importantly, it also eliminates preloading of HSF on HSP82 and SSA4 promoters before heat shock and diminishes HSF binding during heat shock. These observations suggest that prior action of chromatin remodeling complexes is necessary for the activator binding.
To characterize a group of patients with follicular lymphoma (FL) with leukemization and to evaluate the efficiency of different therapy options (R-CHOP/R-FMC/high-dose chemotherapy (HDCT)).
18 ...(7.2%) out of 250 patients diagnosed with FL, who were examined and treated at the National Research Center for Hematology, Ministry of Health of the Russian Federation, were found to have leukemic FL (tumor cells in the peripheral blood smears were detected by cytology and flow cytofluorometry. Eight of the 18 patients had extranodal foci of involvement: lung, stomach, spleen, lumbar muscles, upper jaw, and vertebrae. Bone marrow was involved in 17 of the 18 patients. Tumor biopsy specimens displayed a morphological pattern of indolent FL in the majority of patients (10 of the 18 patients had cytological grade 1-2 tumors and 14 patients had a nodular or nodular-diffuse tumor growth pattern). The patients underwent R-CHOP/R-FMC) or HDCT cycles as first-line therapy, followed by autologous stem cell transplantation (auto-SCT).
The median follow-up was 66 months (range 12-217 months). The 5-year overall survival (OS) and progression-free survival (PFS) rates were 70% (10% SEM) and 35% (15% SEM), respectively. The median OS was not reached; the median PFS was 3 years.
Leukemic FL is characterized by low OS and PFS rates. The most effective chemotherapy regimens were R-CHOP, followed by HDCT and auto-SCT in first remission or R-FMC. These cycles can to a greater extent achieve a complete eradication of the bone marrow tumor clone. Due to the relapsing course of FL and the aggressiveness of leukemic FL, it is expedient to carry out auto-SCT in first remission.
Abstract
The article deals with the formation of larch stands on the upper forest boundary in extreme forest conditions under the influence of climate change.
The literature and our own data on N₂-fixing bacteria forming symbioses with plants and providing convenient models to study the evolution of interspecies (microsymbionts → hosts) altruism are ...considered in the review. It is presented as a deeply reorganized intraspecies altruism implemented in the clonal population of rhizobia (bacteroids → undifferentiated bacteria) under the control of kin selection induced by plant hosts. The analysis of this model suggests that it is possible to engineer practically valuable rhizobial strains in which high N₂-fixing activity is combined with decreased survival outside of plants.
Cover-free codes and separating system codes D’yachkov, A. G.; Vorobyev, I. V.; Polyanskii, N. A. ...
Designs, codes, and cryptography,
2017/1, Letnik:
82, Številka:
1-2
Journal Article
Recenzirano
Odprti dostop
We give some relations between the asymptotic rates of cover-free (CF) codes, separating system (SS) codes and completely separating system (CSS) codes. We also provide new upper bounds on the ...asymptotic rate of SS codes based on known results for CF and CSS codes. Finally, we derive a random coding bound for the asymptotic rate of SS codes and give tables of numerical values corresponding to our improved upper bounds.
to evaluate the efficiency of high-dose chemotherapy (HDCT) with further autologous blood stem cell transplantation (auto-BSCT) in the first-line therapy of patients with follicular lymphoma (FL) and ...poor prognostic factors.
In 2000 to 2015, the National Research Center for Hematology, Ministry of Health of the Russian Federation, performed therapy in 39 patients with FL and poor prognostic factors (a total of 215 patients with FL). The R-CHOP treatment was done as induction therapy. Sequential HCT and further auto-BSCT were performed in 29 (74%) of the 39 patients, who had shown a partial tumor response to the induction therapy or achieved partial remission after 4-6 cycles of CT, but had poor prognostic factors. 22 of the 29 patients underwent auto-BSCT in first-line therapy after induction R-CHOP regimens. Among them, there were 17 men with a median age of 46 years (31-68 years). 21 of the 22 patients were recorded to have Stage IV by the Ann Arbor staging classification. Bulky peritoneal and retroperitoneal tumors larger than 7 cm were detectable at disease onset in 14 of the 22 cases. Two patients were noted to have phenomena of leukemization. 16 patients had bone marrow (BM) involvement. According to the Follicular Lymphoma International Prognostic Index-1 (FLIPI-1), the patients were divided into 3 groups: 1) a low risk (n=5); 2) an intermediate risk (n=3); a high risk (n=14). B-symptoms were observed in 16 cases. 16 patients were diagnosed with cytological grade I-II FL and 6 had grade IIIA. According to the tumor proliferative pattern, the distribution turned out to be as follows: nodular (n=6), nodular-diffuse (n=13), and diffuse (n=3). The proliferative activity index averaged 30% (8-90%). Serum and urine proteins were immmunochemically assayed in 18 cases, out of them 8 patients were diagnosed as having serum β2-microglobulin concentrations above normal as a poor prognostic factor. In 14 of the 22 patients, the activity of lactate dehydrogenase was greater than normal (266-7806 U/l).
Out of the 22 patients, 20 who have undergone auto-BSCT in first-line therapy are survivors and have remission of the underlying disease: 18 and 2 patients achieved complete and partial remission, respectively. The follow-up period was 7 to 178 months (median, 32 months). After auto-BSCT in the first remission, 2 patients developed disease recurrences: an early recurrence after 9 months in one case and a late recurrence 6 years after completion of therapy in the other.
The first prospective study of intensive therapy for FL in Russia has demonstrated that HDCT with further auto-BSCT in first-line therapy allows complete remission in patients with poor prognostic factors and higher overall and progression-free survival rates.
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