Target Band Research Articles

Optically Invisible Artificial Magnetic Conductor Subarrays for Triband Display-Integrated Antennas

This article proposes a novel concept of an optically invisible artificial magnetic conductor subarrays for bandwidth improvement of display-integrated antennas in millimeter-wave spectrums. The proposed subarrays consist of two unit-cell types that are arranged as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4 \times 4$ </tex-math></inline-formula> super cells to cover target bands of a slotted dipole antenna with triband resonances. The optical transparency is realized by using thin-metal meshes, and both solid and thin-metal mesh prototypes are fabricated to demonstrate the proposed concept from antenna characteristics standpoints. The mesh prototype exhibits the measured 10-dB matching bandwidth of 25.9% at 28.2 GHz with an average gain of 1.12 dBi, which is similar to 21.1% at 27.5 GHz and 1.25 dBi of the simulated results. These results confirm that the proposed concept is feasible to broaden bandwidths of the triband antenna, while maintaining the optical transparency of 85.1%.

Assessing Australian Monetary Policy in the Twenty‐First Century*

Using the Reserve Bank of Australia's MARTIN model, we compare actual monetary policy decisions with a counterfactual in which the cash rate is set according to an optimal simple rule. We find that monetary policy played a crucial role in avoiding a potential recession in 2001 and mitigating the downturn in 2008–09. By contrast we find that the cash rate was too high during 2016–19, keeping inflation below the Reserve Bank's target band. Optimal monetary policy in 2016–19 would have involved a substantially lower cash rate and produced significantly better employment outcomes.

Development and Comparison of Seminested PCR, qPCR, and LAMP for the Rapid Detection of Arthrinium phaeospermum, the Causal Agent of Bamboo Blight

Bambusa pervariabilis × Dendrocalamopsis grandis blight is a newly discovered disease in bamboos that has caused substantial economic loss to the affected areas. With the purpose of carrying out rapid detection of Bambusa pervariabilis × Dendrocalamopsis grandis blight caused by Arthrinium phaeospermum during the incubation period, three sets of detection assays were established: seminested PCR, real-time quantitative PCR, and LAMP. The specificity, sensitivity, and effectiveness of these assays were also detected. The results showed that the three assays were able to specifically amplify the target bands from five strains of Arthriniumphaeospermum from different sources, but none of the other 18 strains were able to obtain the specific bands. The sensitivity of the established seminested PCR, LAMP, and real-time quantitative PCR assays were 100, 10, and 1 pg/μL, respectively. The presence of A. phaeospermum could be detected in the early stage of disease using the total DNA of infected hybrid bamboo tissue as a template. The three systems established in this study are of great significance for the early diagnosis and rapid detection of hybrid bamboo blight.

Design and realization of frequency and mode electronically reconfigurable metamaterial stopband filter for wireless communication systems

ABSTRACT This paper addresses the growing need for multifunctioning microwave components by proposing a miniaturized reconfigurable stopband filter. The compact size is the outcome of the novel metamaterial split-ring resonator used for realizing this filter. Six PIN diodes are used to achieve real-time frequency and mode reconfigurability. This filter is designed to reject three important frequencies in wireless communication systems: 1.9, 2.4, and 3.6 GHz. Moreover, depending on the use, it is possible to reject one, two, or all the three frequencies, which resulted in seven different cases with three possible modes: single, dual, or triple stopbands. A prototype was manufactured for this filter, and strong agreement between simulation and measurement results is observed. Due to its target bands, this reconfigurable stopband filter is suitable for various cellular communication technologies from 3 G and 4 G up to 5 G and many other S-band applications.

The exchange rate passthrough to consumer price inflation in South Africa: has the inflation target band induced a structural change in the size of passthrough?

The exchange rate passthrough to consumer price inflation in South Africa: has the inflation target band induced a structural change in the size of passthrough?

Republic of Kazakhstan: 2021 Article IV Consultation-Press Release; Staff Report; Staff Statement; and Statement by the Executive Director for Kazakhstan

Activity returned to its pre-COVID level in 2021. Inflation remains well above the NBK’s 4–6 percent target band, and spillovers from sanctions on Russia will exacerbate price pressures and weaken economic growth in 2022. Kazakhstan benefits from strong fiscal and external buffers but risks to the outlook are elevated due to the uncertain impact on Kazakhstan of the sanctions on Russia and heightened domestic tensions since the January social unrest episode. In the medium term, non-oil growth under the baseline is expected to converge to about 4 percent. Sustainable growth will require greater economic diversification. Climate-related challenges are acute for Kazakhstan given its outsized hydrocarbon sector, high per-capita greenhouse gas emissions, and low domestic energy prices.

Molecular Authentication of Twelve Meat Species Through a Promising Two-Tube Hexaplex Polymerase Chain Reaction Technique.

Frequent meat frauds have aroused significant social attention. The aim of this study is to construct a two-tube hexaplex polymerase chain reaction (PCR) method offering accurate molecular authentication of twelve meat species in actual adulteration event. Deoxyribonucleic acid (DNA) sequencing demonstrates that designed primers can specifically amplify target species from genomic DNA mixture of six species in each tube reaction, which showed 100% accuracy of horse (148 bp), pigeon (218 bp), camel (283 bp), rabbit (370 bp), ostrich (536 bp), and beef (610 bp) as well as turkey (124 bp), dog (149 bp), chicken (196 bp), duck (277 bp), cat (380 bp), and goose (468 bp). A species-specific primer pair produced the target band in the presence of target genomic DNA but not non-target species. Through multiplex PCR assays with serial concentration of the DNA mixture of six species in each PCR reaction, the detection limit (LOD) of the two-tube hexaplex PCR assay reached up to 0.05–0.1 ng. Using genomic DNA isolated from both boiled and microwave-cooked meat as templates, PCR amplification generated expected PCR products. These findings demonstrate that the proposed method is specific, sensitive and reproducible, and is adequate for food inspection. Most importantly, this method was successfully applied to detect meat frauds in commercial meat products. Therefore, this method is of great importance with a good application foreground.

The Effect of Glucosinolates on the Growth and Development of Helicoverpa armigera Larvae and the Expression of Midgut Sulfatase Genes

The plant–pest interaction and its mechanisms are a novel research direction for pest control. They provide molecular targets for developing new pesticides and targeted control measures to control insect herbivores. Glucosinolate is a large family of secondary substances found in cruciferous plants that are harmful to herbivorous insects. Specialist herbivores have developed specific anti-defense genes and detoxifying mechanisms against glucosinolate from the host plant, but how generalist herbivores respond to glucosinolate at the molecular level is unknown. In this study, we investigated the effects of different glucosinolate concentrations on the growth and development of Helicoverpa armigera. Moreover, the expression of sulfatase genes (HaSulfs) was also checked following exposure to glucosinolate concentrations. The developmental duration of larvae and pre-pupa of H. armigera was significantly increased by 14.79–25.03% after feeding glucosinolate compared to the control. Quantitative Real-Time PCR (RT-qPCR) was carried out to analyze the expression of HaSulf family genes in the midgut of fifth instar larvae of H. armigera. The results showed that the upregulated expression patterns of HaSulf family genes were diversified after feeding at different concentrations. The expression level of HaSulf was detected with the HaSulf antibody. Only the glucosinolate-fed larvae had a visible target band and were mainly distributed in the midgut wall. Taken together, glucosinolate can significantly affect the growth and development of H. armigera larvae. It can induce the expression of HaSulf in the midgut of H. armigera at gene and protein levels. This study could be useful to understand the development of plant-derived insecticides resistance in H. armigera.

Molecular-based assay for genotyping Leishmania spp. from clinically suspected cutaneous leishmaniasis lesions in the Garmian area, Kurdistan Region of Iraq

Cutaneous leishmaniasis (CL) is highly prevalent in southern Iraq and neighboring countries, but is non-endemic to the Kurdistan Region of Iraq, particularly in the Garmian area. This study aimed to investigate the causative agent of CL at the molecular level by amplifying the small subunit (18S) rRNA and internal transcribed spacer 1 (ITS1) region. The present study was conducted from December 2019 to December 2020 at Kalar General Hospital, Kalar, Kurdistan Region, Iraq. Eighty-five clinical specimens were collected selectively from patients with suspected CL lesions via fine needle aspiration. After parasitic genomic DNA was extracted from the removed fluid, PCR and DNA sequencing targeting the 18S rRNA and ITS1 region were performed for molecular detection and species identification. Additionally, for 14 samples, the target bands of amplified DNA fragments for both 18S rRNA and ITS1 were extracted and sequenced via Sanger method using both the directional primers employed in the PCR. Seventy-one (83.53%) of the 85 suspected patients had CL, based on amplification of 18S rRNA and ITS1 via PCR. The sequence analysis revealed that all samples were Leishmania major. Phylogenetic analysis based on ITS1 was also performed. Our study revealed that our molecular method was an efficient technique for detecting CL and a valuable method for identifying Leishmania species in clinical samples. Sequence analysis indicated that the causative agent of CL in the Garmian area was L. major and the disease was rural in origin.

Dual-Band Four-Antenna Module Covering N78/N79 Based on PIFA for 5G Terminals

To satisfy the requirement of the sub-6 GHz bands coverage and the 4 × 4 multiple-input--multiple-output (MIMO) specification for fifth-generation (5G) era, a dual-band four-antenna module covering partial 5G bands N78 (3.4–3.6 GHz) and N79 (4.8–4.9 GHz) is proposed for 5G terminal applications. Based on a quarter-circle-shaped dual-mode slotted planar inverted-F antenna (PIFA), the two target bands are covered by the fundamental TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> mode and a hybrid higher-order mode combined by quasi-TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> and quasi-TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0,1/2</sub> modes. The four-antenna module is composed of four such PIFA elements that are arranged in a sequentially rotated layout. It presents a circular shape with a diameter of 39.4 mm and is with a low profile of 1.2 mm. The measured results show that the reflection coefficients of the four elements basically cover the target bands; across N78 and N79, the isolations are better than 8.5 and 17.6 dB for the neighboring elements, and 19.4 and 18.5 dB for the diagonal elements; the average total efficiencies of the four elements are between 38.3% and 39.5% for N78 and 39.3% and 42.6% for N79; all the envelope correlation coefficients are lower than 0.42.

A Frequency-Selective Digital Predistortion Method Based on a Generalized Indirect Learning Architecture

Frequency-selective (FS) digital predistortion (DPD), which focuses on suppressing the nonlinear distortion at a specific band, has gained increased interest in recent years. However, there is a lack of a general FS DPD approach that is applicable to most scenarios and is suitable for practical implementation. This paper proposes an FS DPD method based on a generalized indirect learning architecture (GILA). Our work on this GILA-based FS DPD method is composed of two contributions. First, an FS Volterra series model structure, which consists of a basic linear part and a partial-band pre-compensation part, is proposed to construct an FS predistorter. Second, a GILA-based identification method is proposed to extract coefficients of the FS predistorter with the FS Volterra series model structure. The proposed GILA-based FS DPD is a general method with low complexity for implementation. Both simulations and experiments verify that the target band of the DPD linearization is arbitrary for the proposed GILA-based FS DPD method. As a special case, when using the proposed method to focus on suppressing the out-of-band distortion, the adjacent channel power ratio performance of the proposed method can be 7.1 dB better than that of the conventional full-band DPD.

Extra Wide Band MIMO Antenna with High Isolation and Low Correlation at 38 GHz mm-Wave Frequency Band for 5G Applications

A compact wide-band Multiple Input Multiple Output (MIMO) antenna having highest isolation and least correlation for millimeter-wave 5G communications is proposed in this paper. Firstly, a single antenna was designed and simulated to be working at 38 GHz, a potential target band for 5G applications. It consists of a 5-shaped radiating patch, with partial ground plane. Its length is adjusted and a wide bandwidth is obtained. Then, the two antenna elements are closely positioned with edge-to-edge spacing of 1 mm (0.55 λ, with λ is the free space wavelength at resonance). Thanks to the technique of spatial diversity, a high degree of isolation is attained; more than 25 dB in the whole bandwidth. Moreover, correlation value is under 0.0002 in the working band. The prototype antennas are fabricated and measured. The result indicates that this antenna shows a reflection coefficient under -10 dB over a range of frequencies from 32.3 to 54.6 GHz (BW=22.3 GHz, 58.68% fractional bandwidth). The antenna presents a high realized gain of 7.12 dBi and radiation efficiency of about 82.46% at the desired frequency. Due to these results, our antenna may be regarded a suitable candidate for mm-wave 5G MIMO applications.

Development of polymorphic SSR markers and their applicability in genetic diversity evaluation in Euptelea pleiosperma

Euptelea pleiosperma is a characteristic species of East Asian flora with both ornamental and scientific values. Based on the reduced-representation sequencing (RRS) technology of RAD-Seq, this study conducted high-throughput Illumina paired-end sequencing to find SSR marker information in the genome of E. pleiosperma, and to screen and verify polymorphism of SSR markers. We obtained 5.5G of high-quality data using RAD-Seq. The total number of contigs of the RAD tags was 299,376, with the maximum contig length of 2,062 bp and the average length of 445 bp. From these sequences, we identified 20,718 SSR loci, with a distribution density of one SSR per 6.45 kb (1/6.45 kb). Among all SSRs, dinucleotides (52.00%) were the most detected SSRs, followed by mononucleotides (21.63%). AG/CT was the dominant motif in the SSR loci, accounting for 34.8%. Primers were successfully designed for 14,593 loci, and 100 pairs of these primers were randomly selected for chemical synthesis and validated by SSR-PCR amplification in 20 individuals of E. pleiosperma. Seventy-nine primers were able to amplify the target bands. Cervus 3.0 software was used to analyze the selected 20 SSR loci with good polymorphism. For the 20 SSR markers, the number of alleles ranged from 4 to 9, and the observed heterozygosity and expected heterozygosity were from 0.35 to 0.75 and 0.541 to 0.875, respectively. The information content of polymorphic loci ranged from 0.463 to 0.848, with an average value of 0.638. Among them, there were 18 highly polymorphic loci, and 20 SSR loci did not deviate from the HardyWeinberg equilibrium. Furthermore, the 20 pairs of SSR primers were used to conduct PCoA analysis based on Nei’s genetic distance of 51 individuals from three populations. The results showed that these SSR markers could distinguish genetic differences based on different geographical locations.

Preparation and identification of short peptides of rice Src homology-3 domain-containing protein 2 for polyclonal antibody production

<p indent="0mm">The successful preparation of specific antibodies is an important step in the study of the physiological and biochemical functions and molecular mechanisms of proteins in plants. In general, polyclonal antibodies are prepared using recombinant proteins expressed in prokaryotes as antigens. However, if the target protein has high sequence homology levels with other proteins, or is difficult to express or purify, specific antibodies cannot be obtained. To address these challenges, short peptide antibody preparation technology has emerged. This technology has gradually been adopted in animals, but it is rarely used in plants. In this study, we analyzed the antigenic epitopes and hydrophilic and homologous amino acid sequences of rice (<italic>Oryza sativa</italic>) SH3P2 and predicted the protein model using the RoseTTAFold system. Then, we selected three amino acid sequences, peptides 3, 4 and 5, having sequence specificity, high hydrophilicity, antigenic epitopes and different peptide chain structures as templates for the synthesis of short-peptide antigens. The short peptides were coupled with KLH and used independently as antigens to immunize New Zealand white rabbits to produce the antibodies Anti-OsSH3P2-1#, Anti-OsSH3P2-2# and Anti-OsSH3P2-3#, respectively. The serum titers of the polyclonal antibodies were detected using an ELISA, and the titers of the polyclonal antibodies were greater than 1꞉512000. Furthermore, we constructed the prokaryotic expression vector pMAL-MBP-OsSH3P2 and successfully induced protein production. To investigate the specificity of these three short-peptide polyclonal antibodies, we first detected their specificities to the recombinant protein pMAL-MBP-OsSH3P2. Anti-OsSH3P2-1# and Anti-OsSH3P2-2# successfully bound to the recombinant protein, with the former having the greatest specificity. Then, the plant endogenous OsSH3P2 protein was used to further detect the specificities of the three antibodies. Target bands were detected in OsSH3P2-over-expressing plants, which had significantly higher protein abundance levels, and wild-type plants. The bands indicated that Anti-OsSH3P2-1# specifically recognized endogenous OsSH3P2 without interference from other homologous proteins. In summary, the short peptide polyclonal antibodies of anti-OsSH3P2-1#, an antigen without α-helix and β-fold structures, recognized OsSH3P2 effectively, and OsSH3P2 homologous proteins did not interfere with the binding, indicating that the antibodies had high immunological specificities. The successful production of polyclonal antibodies against OsSH3P2 short peptides lays a foundation for OsSH3P2-related biological functional studies and shed lights on the production of short-peptide antibodies in plants.

Characteristics and mechanism of heterotrophic nitrification/aerobic denitrification in a novel Halomonas piezotolerans strain.

A strain was isolated from an activated sludge system and identified as Halomonas piezotolerans HN2 in this study, which is the first strain in H. piezotolerans with the capability of heterotrophic nitrification and aerobic denitrification. Strain HN2 showed the maximum nitrogen removal rate of 9.10 mg/L/h by utilizing ammonium at the salinity of 3.0%. Under saline environment, HN2 could remove nitrogen efficiently in neutral and slightly alkaline environments, with the carbon sources of sodium succinate and sodium citrate and the C/N ratio of 15-20, and the maximum removal efficiencies of ammonium, nitrite, and nitrate were 100%, 96.35%, and 99.7%, respectively. The genomic information revealed the presence of amoA, napA, and nosZ genes in strain HN2, and the target bands of nirS were obtained via a polymerase chain reaction. Therefore, we inferred that ammonium was mainly utilized for the growth of strain HN2 through assimilation, and another part of the initial ammonium was converted into nitrate through nitrification, and then into gaseous nitrogen through denitrification. This report indicated the potential application of strain HN2 and other nitrifying and denitrifying Halomonas strains in the removal of nitrogen pollution in marine-related environments and also implies the important role of Halomonas in the nitrogen cycle process of the ocean.

Rapid detection of Decapod iridescent virus 1 (DIV1) by recombinase polymerase amplification

A recombinase polymerase amplification (RPA) assay was established for the rapid detection of Decapod iridescent virus 1 using primers targeted to the virus’s ATPase gene (ORF114R). Optimization experiments showed that the optimal amplification temperature of the RPA assay was 37 °C and that the reaction could be completed within only 15 min. The target band of 15 min. is bright enough. In order to shorten the operational reaction time, consequently, 15 min was the optimal amplification time for our new RPA assay for DIV1. Specificity tests showed that the RPA assay did not exhibit any cross-reactivity with other shrimp pathogens(TSV, MrNV, YHV-1, WSSV, EHP, AHPND, EHNV, RSIV, RGV and IHHNV). Sensitivity tests further showed that the detection limit of the new RPA assay was 200 copies/50 μL, indicating that this assay was more sensitive than a nested polymerase chain reaction (PCR) method. A total of 509 clinical samples were assayed using the RPA and the PCR assays; analysis showed that the RPA method could detect weak-positive samples more effectively than the PCR method. Collectively, these findings indicated that the RPA assay was fast, simple, specific, sensitive and has significant potentials for clinical and on-site testing.

A Dual-Band Dual-Polarized Antenna with Improved Isolation Characteristics for Polarimetric SAR Applications

A dual-band dual-polarized antenna with high isolation characteristics is proposed for polarimetric synthetic aperture radar (PolSAR) applications. The antenna consists of four dipole antennas and 2 × 2 patch antenna arrays operating at the P-band (450–730 MHz) and Ka-band (34–36 GHz), respectively. The dipole antennas and the patch antenna arrays need dual-linear polarization characteristics to acquire PolSAR data. Improvements in the isolation characteristics at the P-band are achieved by inserting a metamaterial absorber with a fractal geometry between the transmitting (Tx) and receiving (Rx) dipole antennas. Without the absorber, the simulated isolation characteristics between the Tx and Rx antennas are lower than 19.2 dB over the target band. On the other hand, with the absorbers, the simulated isolation characteristics are higher than 23.44 dB over the target band, and remarkable improvement is achieved around the resonance frequency of the absorber. The measured results are in good agreement with the simulated ones, showing that the proposed antenna can be a good candidate for PolSAR applications.

Genome-wide simple sequence repeat markers in potato: abundance, distribution, composition, and polymorphism.

Simple sequence repeats (SSRs) are important sources of genetic diversity and are widely used as markers in genetics and molecular breeding. In this study, we examined four potato genomes of DM1-3 516 R44 (DM) from Solanum phureja, RH89039-16 (RH) from Solanum tuberosum, M6 from Solanum chacoense and Solanum commersonii to determine SSR abundance and distribution and develop a larger list of polymorphic markers for a potentially wide range of uses for the potato community. A total of 1,734,619 SSRs were identified across the four genomes with an average of 433,655 SSRs per genome and 2.31kb per SSR. The most abundant repeat units for mono-, di-, tri-, and tetra-nucleotide SSRs were (A/T)n, (AT/AT)n, (AAT/ATT)n, and (ATAT/ATAT)n, respectively. The SSRs were most abundant (78.79%) in intergenic regions and least abundant (3.68%) in untranslated regions. On average, 168,069 SSRs with unique flanking sequences were identified in the four genomes. Further, we identified 16,245 polymorphic SSR markers among the four genomes. Experimental validation confirmed 99.69% of tested markers could generate target bands. The high-density potato SSR markers developed in this study will undoubtedly facilitate the application of SSR markers for genetic research and marker-pyramiding in potato breeding.

Development of a Quantitative PCR Method for Specific and Quantitative Detection of Enterocytospora artemiae, a Microsporidian Parasite of Chinese Grass Shrimp (Palaemonetes sinensis)

Enterocytospora artemiae (EAM) mainly parasitizes the hepatopancreas of Palaemonetes sinensis. Serious infection leads to hepatopancreatic lesions, which greatly reduce the vitality of P. sinensis. Currently, EAM is detected via conventional PCR methods. However, conventional PCR has low sensitivity and cannot be used for accurate quantitative detection of EAM or its parasitic activity in host tissues. In this study, we designed a pair of specific primers based on the sequence of the ribosomal protein S9 gene (RPS9; GenBank accession number: MZ420734) to establish and optimize a SYBR Green I real-time fluorescent quantitative PCR detection method for EAM. Only EAM appeared as a bright and single target band, whereas other microorganisms did not, indicating that the primer for RPS9 had high specificity. This method displayed optimum amplification effects at an annealing temperature of 55°C, and the melting curve of the product produced a single peak. The established method showed a good linear relationship from 2.2 × 108 to 2.2 × 101 copies/μL. The relationship between the number of cycle thresholds (Ct) and the logarithm of the initial template amount (x) conformed to Ct = −3.281 log x + 36.543 (R2 = 0.998). Amplification efficiency was 101.737%, and the lower limit of detection sensitivity was 2.2 × 101 copies/μL. Good intra- and inter-group repeatability was observed within the linear range. The sensitivity of this method was more than 200 times higher than that of nested PCR. Thus, detection data obtained using this method may be useful as a technical reference for rapid and accurate identification of EAM infection and for the prevention and control of EAM during P. sinensis breeding.

Study on AA10 expression in E. coli

The GlcNAc-binding protein A (GbpA) has been known as a virulent factor of Vibrio vulnificus pathogen. Domain 1 of GbpA adhesion takes responsibility of binding both human intestine and the chitinous surface. The domain 1 structure is similar to a polysaccharide monooxygenase (PMO) AA10-type (PMO), which catalyzed oxidation toward the recalcitrant chitin polymer. The role of the VvPMO10 module in catalytic functions has not been fulfilled characterized. To aim of the VvPMO10 study, this protein was cloned to the pET22b system and transformed into the E. coli BL21 (DE3) strain. The recombinant enzyme was expressed at 37 0C with IPTG induced. Total protein was checked by SDS-PAGE method and stained using Coomassie blue solution. The target band showed a band of 20 kDa as expectation. Thus, the heterologous protein was expressed successfully in E. coli BL21 (DE3) strain and becomes the materials for future study.