63 research outputs found
Performance Comparison of Optimization Methods for Flat-Top Sector Beamforming in a Cellular Network, Journal of Telecommunications and Information Technology, 2022, nr 3
The flat-top radiation pattern is necessary to form an appropriate beam in a sectored cellular network and to pro vide users with best quality services. The flat-top pattern offers sufficient power and allows to minimize spillover of signal to adjacent sectors. The flat-top sector beam pattern is relied upon In sectored cellular networks, in multiple-input multiple-output (MIMO) systems and ensures a nearly constant gain in the desired cellular sector. This paper presents a comparison of such optimization techniques as real-coded genetic algorithm (RGA) and particle swarm optimization (PSO), used in cellular networks in order to achieve optimum flat-top sector patterns. The individual parameters of flat-top sector beams, such as cellular coverage, ripples in the flat-top beam, spillover of radiation to the adjacent sectors and side lobe level (SLL) are investigated through optimization performed for 40◦ and 60◦ sectors. These parameters are used to compare the performance of the optimized RGA and PSO algorithms. Overall, PSO outperforms the RGA algorithm
Allergenicity Assessment of Allium sativum Leaf Agglutinin, a Potential Candidate Protein for Developing Sap Sucking Insect Resistant Food Crops
Background: Mannose-binding Allium sativum leaf agglutinin (ASAL) is highly antinutritional and toxic to various phloem-feeding hemipteran insects. ASAL has been expressed in a number of agriculturally important crops to develop resistance against those insects. Awareness of the safety aspect of ASAL is absolutely essential for developing ASAL transgenic plants. Methodology/Principal Findings: Following the guidelines framed by the Food and Agriculture Organization/World Health Organization, the source of the gene, its sequence homology with potent allergens, clinical tests on mammalian systems, and the pepsin resistance and thermostability of the protein were considered to address the issue. No significant homology to the ASAL sequence was detected when compared to known allergenic proteins. The ELISA of blood sera collected from known allergy patients also failed to show significant evidence of cross-reactivity. In vitro and in vivo assays both indicated the digestibility of ASAL in the presence of pepsin in a minimum time period. Conclusions/Significance: With these experiments, we concluded that ASAL does not possess any apparent features of an allergen. This is the first report regarding the monitoring of the allergenicity of any mannose-binding monocot lectin having insecticidal efficacy against hemipteran insects
Influence of anti-site disorder and electron-electron correlations on the electronic structure of CeMnNi
CeMnNi exhibits an unusually large spin polarization, but its origin has
baffled researchers for more than a decade. We use bulk sensitive hard x-ray
photoelectron spectroscopy (HAXPES) and density functional theory based on the
Green's function technique to demonstrate the importance of electron-electron
correlations of both the Ni 3 () and Mn 3 () electrons in
explaining the valence band of this multiply correlated material. We show that
Mn-Ni anti-site disorder as well as play crucial role in enhancing its
spin polarization: anti-site disorder broadens a Ni 3 minority-spin peak
close to the Fermi level (), while an increase in shifts it
towards , both leading to a significant increase of minority-spin states
at . Furthermore, rare occurrence of a valence state transition between
the bulk and the surface is demonstrated highlighting the importance of HAXPES
in resolving the electronic structure of materials unhindered by surface
effects.Comment: Manuscript and Supplementary material, 13 pages, 17 figure
Investigation of the Effect of MDM2 SNP309 and TP53 Arg72Pro Polymorphisms on the Age of Onset of Cutaneous Melanoma
Melanoma accounts for the majority of deaths from skin cancer. Women tend to be diagnosed at a younger age and have better survival than men. A tumor–host interaction might be responsible for these gender-specific differences. Recently, a functional single-nucleotide polymorphism in the promoter of the human homolog of mouse double minute 2 (MDM2) gene was characterized: single-nucleotide polymorphism (SNP)309 increases the MDM2 transcription. In melanoma, the effects for SNP309 and the related tumor protein p53 (TP53) Arg72Pro are inconsistent among published reports. This study investigated the association between SNP309 (RefSNP accession ID (rs)2279744) and TP53 codon 72 (rs1042522) polymorphisms, with outcome in a hospital-based cohort of 990 patients with melanoma. We assessed whether these polymorphisms were associated with clinicopathological and phenotypic characteristics and whether these SNPs affect the age of onset of the disease, recurrence, and survival. No significant associations were found between the SNPs and survival. However, women carrying the SNP309 GG genotype were less likely to be diagnosed at a younger age: odds ratioadjusted<50 0.52 (0.29–0.92). Our results suggest that women carrying the SNP309 GG genotype might be at lower risk of developing melanoma at a younger age compared with those carrying TG or TT. Further studies are needed to determine whether a nearby functional polymorphism is responsible for this effect in premenopausal women
Bulk Electronic Structure of Ni2MnGa studied by Density Functional Theory and Hard X-ray Photoelectron Spectroscopy
A combined study employing density functional theory (DFT) using the
experimentally determined modulated structures and bulk-sensitive hard x-ray
photoelectron spectroscopy on single-crystalline NiMnGa is presented in
this work. For the aforementioned modulated structures, all of the
characteristic features in the experimental valence band (VB) are in excellent
agreement with the theoretical VB calculated from DFT, evincing that it is the
true representation of NiMnGa in the martensite phase. We establish the
existence of a charge density wave (CDW) state in the martensite phase from the
shape of the VB near that shows a transfer of spectral weight in
excellent agreement with DFT. Furthermore, presence of a pseudogap is
established by fitting the near region with a power law function
predicted theoretically for the CDW phase. Thus, the present work emphasizes
that the atomic modulation plays an important role in hosting the CDW phase in
bulk stoichiometric NiMnGa.Comment: *Equal contributio
Variants in Hormone Biosynthesis Genes and Risk of Endometrial Cancer.
We investigated the risk associated with variants in three genes involved in estrogen biosynthesis, CYP11A1, CYP17A1, and CYP19A1, in the population-based case-control study of Estrogen, Diet, Genetics, and Endometrial Cancer. This study was conducted in New Jersey in 2001-2006 with 417 cases and 402 controls. For CYP11A1, there was no association between the number of [TTTTA]( n ) repeats (D15S520) and risk. For CYP17A1, risk was somewhat lower among women with the C/C genotype at T-34C (rs743572) (adjusted OR = 0.65, 95% CI 0.41-1.02). For CYP19A1, risk was lower among women homozygous for the 3-bp deletion (rs11575899) in exon 4 (adjusted OR = 0.44, 95% CI 0.26-0.76), while the number of [TTTA]( n ) repeats was not significantly related to risk: the adjusted OR for n = 7/7 repeats versus n \u3e 7/\u3e7 repeats was 0.81 (95% CI 0.54-1.23). In stratified analyses, results for CYP19A1 were stronger among women with higher (\u3e or =27.4) body mass index: for the homozygous deletion, OR = 0.30 (95% CI 0.15-0.62); for the n = 7/7 genotype, OR = 0.49 (95% CI 0.26-0.93). The interaction between the n = 7/7 genotype and BMI was statistically significant (p = 0.01). The insertion/deletion variant in CYP19A1 appears to be related to risk of endometrial cancer; risk associated with variants in this gene may vary according to BMI
Vitamin D Receptor Gene Haplotypes and Polymorphisms and Risk of Breast Cancer: A Nested Case-Control Study
Observational and experimental studies suggest that vitamin D may influence breast cancer etiology. Most known effects of vitamin D are mediated via the vitamin D receptor (VDR). Few polymorphisms in the VDR gene have been well studied in relation to breast cancer risk and results have been inconsistent
Sun Exposure, Vitamin D Receptor Genetic Variants, and Risk of Breast Cancer in the Agricultural Health Study
Background: Epidemiologic evidence suggests a negative relation between sunlight exposure and breast cancer risk. The hypothesized mechanism is sunlight-induced cutaneous synthesis of vitamin D
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