Contact Engineering Approach to Improve the Linearity of Multilevel Memristive Devices

Physical mechanisms underlying the multilevel resistive tuning over seven orders of magnitude in structures based on TiO2/Al2O3 bilayers, sandwiched between platinum electrodes, are responsible for the nonlinear dependence of the conductivity of intermediate resistance states on the writing voltage. To improve the linearity of the electric-field resistance tuning, we apply a contact engineering approach. For this purpose, platinum top electrodes were replaced with aluminum and copper ones to induce the oxygen-related electrochemical reactions at the interface with the Al2O3 switching layer of the structures. Based on experimental results, it was found that electrode material substitution provokes modification of the physical mechanism behind the resistive switching in TiO2/Al2O3 bilayers. In the case of aluminum electrodes, a memory window has been narrowed down to three orders of magnitude, while the linearity of resistance tuning was improved. For copper electrodes, a combination of effects related to metal ion diffusion with oxygen vacancies driven resistive switching was responsible for a rapid relaxation of intermediate resistance states in TiO2/Al2O3 bilayers.

Structure and electrical resistance of the passivating ZnSe layer on Ge

In this article, we have considered the p-i-n Ge photodetector with ZnSe passivating layer. Passivation layer needs to be protected photodetector from dust, rain drops and other external influences. However, this passivation layer can cause errors in photodetector image. When creating a passivating ZnSe layer on Ge, which is used in p-i-n Ge photodetectors, we found two additional phases GeSe and GeSe2 that do not contradict with their state diagram. The above phases can have an essential effect on performances of the passivating layer. Therefore, to study the electrical resistance of this layer, we prepared model samples of layers containing the GeSe and GeSe2 with the thickness 0.5…1.8 µm and area 1 cm2. To measure the electrical resistance of these layers, we used elastic contacts. The performed measurements have shown that Se layers on Ge have an intermediate resistance between that of ZnSe on Ge and pure Ge, and, therefore, the effect of additional phases practically does not worsen the passivating properties of the ZnSe layer on Ge.

AAC Redberry Hard Red Spring Wheat

AAC Redberry hard red spring wheat (Triticum aestivum L.) has a grain yield significantly higher than the check cultivars Katepwa, and Lillian and is similar to Carberry. AAC Redberry matures in a similar number of days as Katewpa and Lillian, and is significantly earlier maturing than Carberry. AAC Redberry has an awned spike, and a low lodging score indicative of strong straw that is significantly lower than Katepwa and Lillian but significantly higher than Carberry. Plant stature is taller than Carberry, but shorter than Lillian and Katepwa. AAC Redberry expressed resistance to prevalent races of leaf rust, stem rust, yellow rust, loose smut, moderate resistance to common bunt and intermediate resistance to Fusarium head blight. AAC Redberry has quality attributes within the range of the check cultivars and is eligible for grades of Canada Western Red Spring wheat.

Lines derived from coffee BA-10 with resistance to Pseudomonas syringae under field conditions with simultaneous natural infections of the pathovars garcae and tabaci

Bacterial-halo-blight and bacterial-leaf-spot are important coffee diseases caused by Pseudomonas syringae pv. garcae and pv. tabaci, respectively. The most suitable method to control these diseases is the use of resistant cultivars. There are no studies on resistance to Pseudomonas syringae (PS) in coffee derived from BA-10 genotypes. Therefore, the aim of this study was to evaluate the resistance to PS in lines derived from BA-10 under field conditions with simultaneous natural infections of the pathovars garcae and tabaci. 38 F4 and two F5 lines derived from BA-10 were evaluated in a field trial in Londrina, PR, Brazil. The Catuaí Vermelho IAC 81 and IAPAR 59 were the susceptible and intermediate resistant controls, respectively. Resistance to PS was evaluated in January 2017 after 45 months of planting. The grading scale varied from 1 to 5, where grade 1 was plants with more resistance and 5 plants more susceptible. Two F5 lines showed 100% of resistant plants (grades 1 and 2) and the F4 line IAPAR 12201 showed 60% of plants with a high level of resistance to PS (grade 1), while the control Catuaí showed no resistant plant. IAPAR 59 and several F4 lines showed high frequency of plants with intermediate resistance to PS

Intermediate resistance to nematode Meloidogyne paranaensis in Híbrido de Timor coffee genotypes

The aim of this study was to prove that Híbrido de Timor (HdT) accessions are resistance sources to Meloidogyne paranaensis. Two experiments were carried out in a greenhouse at IDR-Paraná (Londrina, Paraná State, Brazil). Open pollinated fruits were harvested from 10 accessions (HdT UFV 380-05, HdT UFV 408-10, HdT UFV 408-11, HdT UFV 408-28, HdT UFV 428-04, HdT UFV 439-14, HdT UFV 443-08, HdT UFV 445-70, HdT UFV 446-138, HdT UFV 448-75) from the EPAMIG/ UFV germplasm bank. Seeds of these accessions were sown to obtain seedlings to test the resistance to M. paranaensis. For each experiment, a completely randomized design was used with 11 treatments, eight replications and one plant per plot. Cultivar Mundo Novo IAC 376-4 was the susceptible check. Seedlings with three to four pairs of leaves were transplanted into plastic cups with a capacity of 700 mL and 1200 eggs. The J2 of M. paranaensis (IP) were inoculated after one month. The assessments were performed 134 days after inoculation, when the data of the number of eggs and J2 per gram of roots and the final population of nematodes (FP) were obtained. The reproduction factor (RF) was calculated using the formula: RF = IP / FP. To classify the resistance levels of the genotypes, the reproduction factor reduction (RFR) was used. It classified the levels from highly resistant to highly susceptible. Different levels of intermediate resistance between the accesses were observed, highlighting HdT UFV 408-28 that presented moderate resistance to M. paranaensis. HdT UFV 408-28 showed a high percentage of plants with intermediate resistance, which can be used in breeding programs aimed at resistance to M. paranaensis

Structure and Electrical Resistance of the Passivating ZnSe Layer on Ge

When creating a passivating ZnSe layer on Ge, which is used in p-i-n Ge photodetector, we found two additional phases GeSe and GeSe2 that does not contradict with their state diagram. The above phases can have an essential effect on performances of the passivating layer. Therefore, to study the electrical resistance of this layer we prepared model samples of layers containing the GeSe and GeSe2 with the thickness 0.5…1.8 µm and area 1 cm2. To measure the electrical resistance of these layers, we used elastic contacts. The performed measurements have shown that Se layers on Ge have an intermediate resistance between that of ZnSe on Ge and pure Ge, and, therefore, the effect of additional phases practically does not worsen the passivating properties of the ZnSe layer on Ge.

Status of Insecticide Resistance of Malaria Vector Anopheles stephensi towards Insecticides in Alwar District of Rajasthan, India

Pyrethroids have been developed as a powerful insecticide that is widely used for space spray and residual indoor spraying, with impregnated nets included in the vector control programme. Insecticide resistance reduces the effectiveness of pesticides. Therefore, the vector susceptibility condition of the Anopheles stephensi is monitored in order to select the active ones. The current study is being conducted in a malaria-ridden area in various parts of the Alwar region of Rajasthan, India, against the malaria vector An. stephensi. The Susceptibility study was conducted by the WHO standardized method using the diagnostic doses of DDT, Alpha-cypermethrin and Deltamethrin. An. stephensi showed intermediate resistance to DDT from all over the study while susceptible to Alpha-cypermethrin and Deltamethrin.

Antibioresistance and Virulence Factors Spectrum in Several Bacterial Strains Isolated from Polluted Environments

Most studies concerning antibiotic resistance are performed on strains isolated from the clinical environment. This phenomenon should not be neglected in bacterial strains isolated from natural or polluted environments, because the phenomenon of virulence and antibiotic resistance occurred in these environments and can contribute to maintaining a reservoir of virulence and antibiotic resistance. This study aimed to assess the resistance factors as well as the antibiotic resistance pattern in bacterial strains isolated from environments polluted with oil products or heavy metals.The strains under study exhibited virulence factors, 85% of the strains had the ability to synthesize amylases, 65% to hydrolyze esculin and gelatin, 50% to produce lecithinases, and hemolysins, and 40% to metabolize casein. To some bacterial straina, the blaNDM and blaIMP resistance genes were identified. These microorganisms showed intermediate resistance to Carbapenem, Monobactam and Aminoglycoside antibiotic classes. Pollutants exert selective pressure on native microorganisms contributing to the development of defense mechanisms against pollution stress, these mechanisms can be used in virulence and antibiotic resistance.