2,132 research outputs found
Aproximació no lineal i mostratge comprimit
En aquest article donem una pinzellada a un camp relativament nou de la
matemàtica, el mostratge comprimit, un terme que correspon a l'expressió compressed
sensing o compressive sampling. És una branca del tractament del senyal que d'alguna
manera ha aparegut de forma natural associada a un altre gran camp ben modern i
present, l'anomenat big data analysis. El mostratge compressiu no tracta pas de la
manipulació de grans bases de dades per extreure'n informació útil, sinó justament de
no generar informació inútil, innecessària. Per a l'exposició, ens referirem breument a
una altra teoria que té entitat per si sola, la teoria de l'aproximació no lineal.In this paper we give an introduction to relatively new field in mathematics, the
so called compressed sensing or compressive sampling. It can be presented as
a branch of signal analysis, whose appearance is related to another important
field, big data analyis. Compressed sensing does not deal with processing big
data sets, but rather with sampling methods that do not lead to unnnecessary
data. For the sake of the exposition we briefly refer as well to non linear approximation
theory
Administration of Brevibacillus laterosporus spores as a poultry feed additive to inhibit house fly development in feces: A new eco-sustainable concept
ABSTRACT The success of a microbial pesticide application against house flies developing in manure should accomplish the uniform mixing of active ingredients with this breeding medium, thus enhancing residual effects. The oral administration of the entomopathogenic bacterium Brevibacillus laterosporus to caged poultry species allows the homogeneous incorporation of its active ingredients with fly breeding media. Feces from treated broilers or hens show toxicity against exposed fly adults and larvae. Insecticidal effects are concentration-dependent with a lethal median concentration (LC50) value of 1.34 × 108 and 0.61 × 108 spores/g of feces for adults and larvae, respectively. Manure toxicity against flies was maintained as long as chickens were fed a diet containing adequate concentrations of B. laterosporus spores. Toxicity significantly decreased after spore administration to birds was interrupted. When poultry diet contained 1010 spores/g, mortality of flies reared on feces exceeded 80%. The use of B. lateroporus spores as a feed additive in poultry production systems fostering a more integrated approach to farming is discussed
Drainage System of Tegalsari Polder for Handling Flood and Tide in Tegal City Indonesia
Although in 2019 the local government of Tegal city Indonesia had constructed a retention basin at drainage system of Siwatu, Tegal Barat, Tegal city with a catchment area of 226 ha, the areas around the system still experienced flood and inundation. This study belonged to a descriptive qualitative research aimed to evaluate the performances of Siwatu drainage system and Tegalsari retention basin. Data of the study included field data and technical data from institutions. Based on the 15-year rainfall data (2014 – 2018) from Pemali - Comal PSDA Office, Central Java Province, Indonesia, the statistical parameters of Cs: 0.0027, Ck: 1.904, Sd: 15.91, Cv: 0.144 were obtained and so Gumbel method distribution was applied in the study, the return period rainfall of 10 years was 138 mm, the flood discharge for Qr.10 years was 9.63 m3/sec., the addition of long storage was 8×2,50×500 m, and the combination of pump addition was of 1 m3/sec. with the long storage of 8×2.00×500 m. By implementing one of the alternative choices, either flood or inundation could be resolved
Dissecting the dynamics of dysregulation of cellular processes in mouse mammary gland tumor
<p>Abstract</p> <p>Background</p> <p>Elucidating the sequence of molecular events underlying breast cancer formation is of enormous value for understanding this disease and for design of an effective treatment. Gene expression measurements have enabled the study of transcriptome-wide changes involved in tumorigenesis. This usually occurs through identification of differentially expressed genes or pathways.</p> <p>Results</p> <p>We propose a novel approach that is able to delineate new cancer-related cellular processes and the nature of their involvement in tumorigenesis. First, we define modules as densely interconnected and functionally enriched areas of a Protein Interaction Network. Second, 'differential expression' and 'differential co-expression' analyses are applied to the genes in these network modules, allowing for identification of processes that are up- or down-regulated, as well as processes disrupted (low co-expression) or invoked (high co-expression) in different tumor stages. Finally, we propose a strategy to identify regulatory miRNAs potentially responsible for the observed changes in module activities. We demonstrate the potential of this analysis on expression data from a mouse model of mammary gland tumor, monitored over three stages of tumorigenesis. Network modules enriched in adhesion and metabolic processes were found to be inactivated in tumor cells through the combination of dysregulation and down-regulation, whereas the activation of the integrin complex and immune system response modules is achieved through increased co-regulation and up-regulation. Additionally, we confirmed a known miRNA involved in mammary gland tumorigenesis, and present several new candidates for this function.</p> <p>Conclusions</p> <p>Understanding complex diseases requires studying them by integrative approaches that combine data sources and different analysis methods. The integration of methods and data sources proposed here yields a sensitive tool, able to pinpoint new processes with a role in cancer, dissect modulation of their activity and detect the varying assignments of genes to functional modules over the course of a disease.</p
Connections between signal processing and complex analylis
Donem una descripció d'una de les línies de recerca del Grup de Teoria de Funcions de la UAB i la UB, que tracta els problemes de mostreig i interpolació en anàlisi del senyal i les seves connexions amb la teoria de funcions de variable complexa.We describe one of the research lines of the Grup de Teoria de Funcions de la UAB UB, which deals with sampling and interpolation problems in signal analysis and their connections with complex function theory
Improvements on dimension growth results and effective Hilbert's irreducibility theorem
We sharpen and generalize the dimension growth bounds for the number of
points of bounded height lying on an irreducible algebraic variety of degree
, over any global field. In particular, we focus on the the affine
hypersurface situation by relaxing the condition on the top degree homogeneous
part of the polynomial describing the affine hypersurface. Our work sharpens
the dependence on the degree in the bounds, compared to~\cite{CCDN-dgc}. We
also formulate a conjecture about plane curves which gives a conjectural
approach to the uniform degree case (the only case which remains open). For
induction on dimension, we develop a higher dimensional effective version of
Hilbert's irreducibility theorem.Comment: 35 page
Hubbard-corrected density functional perturbation theory with ultrasoft pseudopotentials
We present in full detail a newly developed formalism enabling density functional perturbation theory (DFPT) calculations from a DFT+U ground state. The implementation includes ultrasoft pseudopotentials and is valid for both insulating and metallic systems. It aims at fully exploiting the versatility of DFPT combined with the low-cost
DFT+U functional. This allows us to avoid computationally intensive frozen-phonon calculations when
DFT+U is used to eliminate the residual electronic self-interaction from approximate functionals and to capture the localization of valence electrons, e.g., on d or f states. In this way, the effects of electronic localization (possibly due to correlations) are consistently taken into account in the calculation of specific phonon modes, Born effective charges, dielectric tensors, and in quantities requiring well converged sums over many phonon frequencies, as phonon density of states and free energies. The new computational tool is applied to two representative systems, namely CoO, a prototypical transition metal monoxide and LiCoO2, a material employed for the cathode of Li-ion batteries. The results show the effectiveness of our formalism to capture in a quantitatively reliable way the vibrational properties of systems with localized valence electrons
Coherent two-mode dynamics of a nanowire force sensor
Classically coherent dynamics analogous to those of quantum two-level systems
are studied in the setting of force sensing. We demonstrate quantitative
control over the coupling between two orthogonal mechanical modes of a nanowire
cantilever, through measurement of avoided crossings as we deterministically
position the nanowire inside an electric field. Furthermore, we demonstrate
Rabi oscillations between the two mechanical modes in the strong coupling
regime. These results give prospects of implementing coherent two-mode control
techniques for force sensing signal enhancement.Comment: 16 pages, 4 figure
BAT2 and BAT3 polymorphisms as novel genetic risk factors for rejection after HLA-related SCT.
The genetic background of donor and recipient is an important factor determining the outcome of allogeneic hematopoietic SCT (allo-HSCT). We applied whole-genome analysis to investigate genetic variants - other than HLA class I and II - associated with negative outcome after HLA-identical sibling allo-HSCT in a cohort of 110 β-Thalassemic patients. We identified two single-nucleotide polymorphisms (SNPs) in BAT2 (A/G) and BAT3 (T/C) genes, SNP rs11538264 and SNP rs10484558, both located in the HLA class III region, in strong linkage disequilibrium between each other (R2 =0.92). When considered as single SNP, none of them reached a significant association with graft rejection (nominal P<0.00001 for BAT2 SNP rs11538264, and P<0.0001 for BAT3 SNP rs10484558), whereas the BAT2/BAT3 A/C haplotype was present at significantly higher frequency in patients who rejected as compared to those with functional graft (30.0% vs 2.6%, nominal P=1.15 × 10-8; and adjusted P=0.0071). The BAT2/BAT3 polymorphisms and specifically the A/C haplotype may represent a novel immunogenetic factor associated with graft rejection in patients undergoing allo-HSCT
- …