Artificial feeding of Ornithodoros fonsecai (Acari: Argasidae) with the anticoagulant Alsever

Ornithodoros fonsecai is a species of argasid tick endemic to Brazil, described in the “São Miguel” cave located in the municipality of Bonito, state of Mato Grosso do Sul, central-western region of Brazil. The artificial feeding technique makes it possible to study the biology of hematophagous arthropods using artificial or natural membranes, as well as different types of blood and anticoagulants. Thus, the aim of the present study was to feed artificially O. fonsecai second instar (N2) nymphs with rabbit blood using parafilm membrane and the anticoagulant Alsever. Ninety percent of the total N2 nymphs engorged and molted to N3 nymphs between 27 and 30 days after feeding, indicating that the use of this anticoagulant is efficient for artificially feeding O. fonsecai N2 nymphs under laboratory conditions.

COMPARATIVE ANALYSIS ON DIFFERENT FEEDING TECHNIQUES OF TEXTILE ANTENNA FOR GPS-L1 APPLICATION

This paper presents a comparative analysis of textile antenna using different feeding techniques for Global Positioning System (GPS-L1) application. Textile materials which are commonly used in the wearable application has gained much attention due to the flexibility and conformability characteristic of the antenna. Nevertheless, the flexibility of this antenna will introduce the bending and stretching element to its physical structure that may degrades the performance. To ensure the maximum power transfer takes place takes place between the source and the antenna, a suitable feeding method must be identified. In this paper, the microstrip feedline technique and coaxial feeding technique will be studied comparatively using Felt textile material as the substrate with the relative permittivity, ?r of 1.098 and tangent loss, ? of 0.0395. It is attached to a copper tape which act as the conductive material with thickness of 0.035 mm. Using Computer Simulation Technology (CST) Microwave Studio software, the result will be analysed comparatively from the performance validation in return loss, gain, bandwidth, directivity and radiation pattern

Compact Broadband Microstrip Triangular Antennas Fed By Folded Triangular Patch for Wireless Applications

This study presents two new designs of reduced size broadband microstrip patch antennas for ultra-wideband (UWB) operation. A folded triangular patch’s feeding technique, V-shaped slot, half V-shaped slot and shorting pins are employed to design the suggested antennas. The shorting pins are applied at the edge of structures to miniaturize the size of the patches. The suggested design with the V-shaped slot provides the measured impedance bandwidth (S11˂-10 dB) of 3.91-12 GHz (101.7%) for broadband application. In the suggested design with the V-shaped slot, the wide bandwidth with an acceptable size reduction is achieved. By introducing a suggested half design with the half V-shaped slot, the impedance bandwidth of the proposed half structure is improved from 4 to 17.22 GHz. The half design includes a measured impedance bandwidth of 124.6% with reduced size of more than 93% compared to the corresponding full design and an enhanced measured bandwidth of 23%. The obtained radiation and impedance results show that the suggested designs are applicable for wideband operation. Besides, the effects of some basic concepts and surface currents on the suggested structures are investigated to explain their broadband performance.

Breastfeeding technique and associated factors among lactating mothers visiting Gondar town health facilities, Northwest Ethiopia: observational method

Background The breastfeeding technique is explained positioning, attachment, and suckling during breastfeeding. Ineffective breast feeding technique is one of the factors leading to premature discontinuation of breastfeeding and malnutrition. There is a limited study on the assessments of BFT and associated factors among lactating mothers in the study area. Therefore, the study aimed to assess breastfeeding technique and the associated factors among lactating mothers visiting Gondar town health facilities, Northwest Ethiopia. Methods An institution-based cross-sectional study was conducted from February 20 to March 20, 2020. An observational checklist and structured interviewer-administered questionnaire were applied to collect the data. The data were entered into Epi-Data 4.6 version and transferred to analyzed using SPSS version 20. Bi-variable and multivariable logistic regressions were performed to identify the association. The strength of association was identified using odds ratio with a 95% confidence interval (), and a p-value of 0.05 was declare as statistically significant. Results The proportion of effective BFT was 48% (95%, CI: 43.0–53.0%). The likelihood of applying proper BFT among age group of 18–20 years was 70% lower than (AOR = 0.3; 95% CI: 0.11–0.83) age group > 30 years. The odds of effective BFT in primipara mothers were 49% (AOR = 0.51; 95% CI: 0.32–0.82) lower compared to multiparous mothers. Likewise, the provability of effective BFT was 55% (AOR = 0.45; 95% CI: 0.29–0.70) times lower in women who had no counseling immediately after delivery compared to their counterparts. Moreover, effective breast feeding technique mothers who have breast problem was 78% lower than (AOR = 0.22; 95% CI: 0.07–0.68) mothers who have no breast problem. And mothers who had counselling of BFT during ANC follow up was 55% (AOR = 0.45; 95% CI: 0.29, 0.70) lower than mothers who had no counseling. Conclusion Just under half of the women in the study area applied proper breast feeding technique Younger and primipara mothers poorly performed to effective BFT. But women having counseling during antenatal care follow-up and immediately after delivery and not having breast problems applied BFT effectively. Hence, special emphasis have to give for younger and primipara mothers. Besides, educate the mother for preventing breast problems and working on enhancing counseling at postnatal clinic.

Design of Wideband Elliptical Ring Monopole Antenna Using Characteristic Mode Analysis

This paper presents the systematic design of an elliptical ring monopole wideband antenna using characteristic mode analysis. The modal analysis is used to analyze the bandwidth and the radiation performance of the radiating patch. The resonance frequencies of three characteristic modes are close to each other with similar modal current distributions and characteristic fields. These three characteristic modes are simultaneously excited by an effective feeding technique. The proposed model achieves wideband characteristics. The proposed model is printed on an inexpensive FR4 substrate with a size of 20 mm × 18 mm × 1.6 mm and has a wide impedance bandwidth of 124.4% in the range of 3.6–15.46 GHz. The prototype has been fabricated and the measured results show good agreement with simulated results. The antenna will cover WLAN, WiMAX, Wi-Fi, and X-band applications.

A Simple Printed Cross-Dipole Antenna with Modified Feeding Structure and Dual-Layer Printed Reflector for Direction Finding Systems

In this paper, a simple printed cross-dipole (PCD) antenna to achieve a right-hand circular polarization (RHCP) at the L/S-band for direction finding (DF) systems is presented. The radiating part of the antenna consists of two printed dipoles that interlock with each other and are mounted orthogonally on a dual-layer printed reflector. To connect the feedlines of the dipole elements to the antenna’s feed network, which is located on the backside of the reflector, a through-hole signal via (THSV) is employed as the signal interconnection instead of the mainstream approach of using coaxial bead conductor. This feeding technique provides a degree of freedom to control the impedance of the signal path between the feedlines and the feed network in the numerical simulation for improved matching conditions. The proposed THSV extending through the dual-layer printed reflector is more reliable, durable, and mechanically robust to stabilize the matching conditions of the fabricated antenna in contrast to the coaxial-based approach that is more susceptible to impedance mismatch due to solder fatigue. Thus, the proposed PCD antenna offers advantages of broadband, flexible impedance matching, and fabrication ease. The antenna exhibits an impedance bandwidth (IBW) of 59% (1.59–2.93 GHz), a 3-dB axial ratio bandwidth (ARBW) of 57% (1.5–2.7 GHz), and a peak of 7.5 dB within the operating frequency band.