Patchwork of COVID-19 certificates to impede travel

Significance Despite this, there are no common standards for validating vaccination and COVID test results. This is hampering national-level disease containment efforts and also regional and international travel. Impacts Lack of state capacity to produce reliable health records is a major constraint for developing countries. The black market in fraudulent vaccination and test results will proliferate. Political divisions over vaccine mandates will intensify if digital certificates become mandatory in a wider variety of contexts.

Monitoring and Modeling of Saline-Sodic Vertisol Reclamation by Echinochloa stagnina

Soil salinity due to irrigation is a major constraint to agriculture, particularly in arid and semi-arid zones, due to water scarcity and high evaporation rates. Reducing salinity is a fundamental objective for protecting the soil and supporting agricultural production. The present study aimed to empirically measure and simulate with a model, the reduction in soil salinity in a Vertisol by the cultivation and irrigation of Echinochloa stagnina. Laboratory soil column experiments were conducted to test three treatments: (i) ponded bare soil without crops, (ii) ponded soil cultivated with E. stagnina in two successive cropping seasons and (iii) ponded soil permanently cultivated with E. stagnina with a staggered harvest. After 11 months of E. stagnina growth, the electrical conductivity of soil saturated paste (ECe) decreased by 79–88% in the topsoil layer (0–8 cm) in both soils cultivated with E. stagnina and in bare soil. In contrast, in the deepest soil layer (18–25 cm), the ECe decreased more in soil cultivated with E. stagnina (41–83%) than in bare soil (32–58%). Salt stocks, which were initially similar in the columns, decreased more in soil cultivated with E. stagnina (65–87%) than in bare soil (34–45%). The simulation model Hydrus-1D was used to predict the general trends in soil salinity and compare them to measurements. Both the measurements and model predictions highlighted the contrast between the two cropping seasons: soil salinity decreased slowly during the first cropping season and rapidly during the second cropping season following the intercropping season. Our results also suggested that planting E. stagnina was a promising option for controlling the salinity of saline-sodic Vertisols.

Structural Integrity of Polymeric Components Produced by Additive Manufacturing (AM)—Polymer Applications

In the work presented herein, the structural integrity of polymeric functional components made of Nylon-645 and Polylactic acid (PLA) produced by additive manufacturing (Fused Deposition Modelling, FDM) is studied. The PLA component under study was selected from the production line of a brewing company, and it was redesigned and analyzed using the Finite Element Method, 3D printed, and installed under real service. The results obtained indicated that, even though the durability of the 3D printed part was lower than the original, savings of about EUR 7000 a year could be achieved for the component studied. Moreover, it was shown that widespread use of AM with other specific PLA components could result in even more significant savings. Additionally, a metallic hanger (2700 kg/m3) from the cockpit of an airplane ATR 70 series 500 was successfully redesigned and additively manufactured in Nylon 645, resulting in a mass reduction of approximately 60% while maintaining its fit-for-purpose. Therefore, the components produced by FDM were used as fully functional components rather than prototype models, which is frequently stated as a major constraint of the FDM process.

Liberibacter solanacearum interacts with host psyllid vitellogenin with its membrane proteins

Candidatus Liberibacter solanacearum (CLso) haplotype D, transmitted by the carrot psyllid Bactericera trigonica is a major constraint in carrot production in Israel. Understanding the molecular interactions between the psyllid vector and CLso can facilitate non-chemical approaches for controlling CLso caused-diseases. In this study, we used CLso outer membrane protein (OmpA) and flagellin as baits to screen for psyllid interacting proteins in a yeast-two hybrid assay. We identified psyllid vitellogenin (Vg) protein to interact with both OmpA and flagellin of CLso. As Vg is often involved in innate immunity with its expression tightly linked to autophagy, a major component of the immune response in the cell, we also analyzed the expression of autophagy-related genes to further elucidate this interaction. We used the juvenile hormone (JH-III) to induce the expression of Vg, thapsigargin for suppressing autophagy, and rapamycin for inducing autophagy. The results revealed that Vg negatively regulates autophagy and vice versa. JH-III induced Vg expression significantly suppressed autophagy and, the levels of CLso significantly increased resulting in significant mortality of the insect. Although the specific role of Vg remains obscure, the findings presented here identify Vg as an important component in the insect immune responses against CLso and may help in understanding the initial molecular response in the vector against Liberibacter.

Seawater Intrusion into Coastal Aquifers

This editorial presents a representative collection of 11 papers presented in the Special Issue on Seawater Intrusion into coastal aquifers. Coastal aquifers are one of the most important water resources in the world. In addition, the natural discharge of freshwater to the sea as submarine groundwater discharge (SGD) has an important role in the ecology of marine environments. The dynamics of seawater and freshwater within coastal aquifers are highly sensitive to disturbances, and their inappropriate management may lead to the deterioration of water quality. In many coastal aquifers, seawater intrusion has become the major constraint imposed on groundwater utilization. Groundwater exploitation and climate variations create dynamic conditions, which can significantly increase seawater intrusion into aquifers and may result in the salinization of wells.

Pratiques et contraintes de l’élevage de la chèvre rousse de Maradi en milieu rural au Niger

Au Niger, l’élevage caprin occupe une place importante dans l’économie des ménages ruraux. Une étude a été conduite dans la région de Maradi afin de caractériser les pratiques de gestion des élevages des chèvres rousses et analyser leurs contraintes. Ainsi, 180 agro-éleveurs répartis dans 12 villages de la région ont été questionnés. Les thèmes abordés au cours des interviews ont porté sur : les caractéristiques du ménage, les objectifs de production, le mode de conduite des animaux, la gestion de l’alimentation, la santé animale ainsi que les contraintes auxquelles les producteurs font face. Les résultats ont révélé que la majorité (72,8%) des propriétaires des caprins sont des femmes. Les caprins sont élevés en priorité comme épargne pour subvenir aux besoins du ménage. Pendant la saison sèche, plus de la moitié (51%) des éleveurs font recours à l’achat du son de blé pour la complémentation des animaux. Diverses sources des compléments minéraux sont utilisées, notamment le sel de cuisine, les pierres à lécher, le natron et le sel de Bilma. La pénurie d’aliments a été identifiée comme la contrainte majeure de l’élevage caprin (57,8%). Elle est suivie par les maladies animales (17,2%) et la stabulation en saison de pluies (7, 8%). L’amélioration de l’élevage de la chèvre rousse passe par la prise en compte de toutes les contraintes de production. English title: Practices and constraints of Maradi red goat breeding in rural areas in Niger In Niger, goat farming plays an important role in the economy of rural households. A study was conducted in the Maradi region to characterize the management practices of red goat farms and analyze their constraints. Thus, 180 agro-pastoralists spread out in 12 villages of the region were questioned. The themes addressed during the interviews included: household characteristics, production objectives, animal husbandry, feed management, animal health and the constraints faced by producers. The results revealed that the majority (72,8%) of goat owners were women. The feeding system is based on natural pastures and crop residues. During the dry season, more than half (51%) of the farmers used wheat bran for animal complementation. Various sources of mineral supplements are used, including cooking salt, lickstones, natron and Bilma salt. Food shortage has been identified as the major constraint to goat farming (57.8%), followed by animal diseases (17.2%) and stalling during the rainy season (7.8%). The improvement of the breeding of the red goat requires the taking into account of all the constraints of production.

Entrepreneurial feminism in Kigali

Entrepreneurship has been attributed to a masculine career in many economies. Rwanda was no exception to the discrimination of women in entrepreneurship. Due to gender, stereotype, and patriarchy, Rwandan women were not free in deciding to participate in entrepreneurial feminism. Some women became liberalists to break the glass ceiling to launch entrepreneurial feminism. They faced constraints that included a lack of entrepreneurship skills, market opportunity, and fear of failure. This article aimed to explore how gender affects new entrepreneurial feminism creation in Kigali. A quantitative approach used to collect survey data from 409 women-owned SMEs in Kigali were selected purposively. The findings indicated that most women-owned SMEs in Kigali started a necessary business due to unemployment. In contrast, those who needed time to care for their family while generating income launched the opportunity business. (64.3%) accepted permission from partners to start a business. While (24.9%) broke the glass ceiling. A lack of entrepreneurship skills was the major constraint they faced.

Pengembangan Sistem Komunikasi Data Dan Jaringan Komputer Dengan Penerapan Wireless Distribution System (WDS) di SMK Negeri 1 Pringgabaya

At Present, many schools have used wireless networks that are used to support wired networks. Cable network is used as an amplifier of access point to make internet access for users. The problems of networking using these cables can be a major constraint to inaccessible places that can reduce the flexibility of usage. The solution for this problem is to develop and implement Wireless Distribution System (WDS) on the access point. WDS is a system to develop wireless internet network without having to use cable as backbone for access point but to take advantage of wireless network path from access point. The parameters used in the WDS system are the parameters of jitter, througput, delay and packet loss. WDS performance can be analyzed so that will be known comparison of access point performance results with cable backbone

Constraints Analysis of Shrimp Farming in the Coastal Belt of South Gujarat

The study examined the constraints analysis of shrimp farming in the coastal belt of South Gujarat. From the South Gujarat region, mainly four districts, namely, Valsad, Navsari, Surat, and Bharuch districts, were selected purposively to study the socio-economic characteristics of shrimp farmers. From each district, two talukas were selected purposively according to the availability of shrimp farmers. After that, two villages from each taluka and from each village, fifteen farmers were selected by simple random sampling (SRS) method. Thus, a total of 240 shrimp farmers were selected for this study. The present study was the vital work in this area which revealed that the disease problem was ranked as the most crucial constraint followed by poor quality of seeds. Feed cost was a third major constraint as reported by shrimp farmers in the study area. The other important constraints identified in the study area were lack of credit, lack of co-operation among shrimp producer’s, lack of technical guidance, involvement of middleman, lack of quality control agencies, lack of government support and losses due to theft that resulted in low productivity etc.