Field Screening Research Articles

Evaluation of Tolerance and Selection of Heat-Tolerant Woody Plants against Heat Stress

Heat-tolerant species have become increasingly important because of climate change; however, a selection system for woody plants is not well established. This study was conducted to establish a selection system for heat-tolerant woody plant species and to select heat-tolerant species. After selecting heat-tolerant woody plants and applying heat stress to 27 species, the electrolyte leakage index (ELI) was measured. The ELI of the heat-tolerant species was lower than that of the non heat-tolerant species, and they survived well after heat stress treatment. For the preselected species, the degree of cell death was measured by Evans blue staining method, and the heat stress recovery ability was measured by a 3,3′-diaminobenzidine (DAB) staining method. The species showed less cell death even after heat treatment, and oxidative stress was low after recovery from heat stress. Traditional screening methods are mainly performed through field screening; however, this is difficult because it requires many samples and considerable time. The results of this study are relatively rapid, reproducible, and highly sensitive, so it is judged to be a method that can complement the existing traditional method as a heat-tolerant plant selection system. The results of this study can be widely used for the selection and breeding of heat-tolerant plants in preparation for climate change.

Field Screening of F2 Population (Muktakeshi × Pant samrat) to Observe Phomopsis Fruit Rot in Brinjal

Brinjal is one of the most popular vegetables of India and equally widespread throughout the world. However, this crop is affected a lot by various diseases which are the major production constraints and Phomopsis fruit rot and blight is second most devastating diseases of brinjal in India. Development of resistant genotypes is the most economical and environment friendly way to control the disease, for which proper screening of the segregating lines is crucial. For this the F2 line of Muktakeshi × Pant samrat were screened in field conditions. Among the 181 plants producing fruits, Phomopsis fruit rot was observed in fruits of 160 plants, while 21 plants remained immune.

Field screening of soybean genotypes against green semilooper, Chrysodeixis acuta (Fabricus)

Field screening of soybean genotypes against green semilooper, Chrysodeixis acuta (Fabricus)

Building accelerated plant breeding pipelines: Screening to evaluate lima bean resistance to root-knot nematode in diverse inbred lines and segregating breeding populations.

Lima beans (Phaseolus lunatus) are a cornerstone crop of Delaware's processing vegetable industry. Root-knot nematodes (RKN; Meloidogyne spp.) cause galling of root systems which severely reduces yield. Durable host resistance is an effective management strategy for RKN, but availability of resistant lima bean cultivars is limited. To overcome these challenges, breeding pipelines must simultaneously advance pre-commercial lines and identify new resistance sources with potential for incorporation into the breeding program. Inoculated field trials were conducted in 2021-2022 to evaluate three M. incognita resistant, pre-commercial experimental lines for resistance traits and yield potential in comparison to commercial standards, 'Cypress' and 'C-elite Select'. DE1306635 had the highest yield and reduced galling and reproduction compared to 'Cypress', and is a candidate for commercial release. To continue the breeding pipeline, 256 lima bean inbred accessions from around the world were assessed from 2022-2023 in greenhouse and field screenings to identify novel sources of resistance in the lima bean gene pool. This method allows for evaluation and/or advancement of three generations per year. The full panel was initially evaluated for root galling and 60 accessions were selected for additional field and greenhouse screening: 25 large- and 25 small-seeded with the lowest gall ratings, 5 high-gall controls, and 5 commercial standards. Seven accessions with reduced M. incognita galling and reproduction were identified, including two known resistant lines and five newly identified genotypes. The resistance carried by these genotypes will be further characterized to assess their potential use in lima bean RKN resistance breeding.

Nonlinear modeling of ELM mitigation with RMP on HL-2A

Nonlinear modeling of mitigation of the edge localized mode (ELM) with resonant magnetic perturbation (RMP) is performed for the HL-2A tokamak, utilizing the three-dimensional (3D) magnetohydrodynamic code JOREK. Based on the 3D equilibrium established after application of the n=1 ( n is the toroidal mode number) RMP at 4.9kAt coil current with odd parity, ELM mitigation is successfully simulated consistent with the experimental result. Nonlinear simulations show strong mode coupling among toroidal Fourier harmonics, allowing redistribution of the magnetic energy such that the most unstable toroidal mode saturates at a lower level. This magnetic energy cascade offers an explanation of the RMP-induced ELM mitigation achieved in HL-2A. Detailed examination of the simulation results shows persistent resonant field screening even during the ELM mitigation phase. Finite plasma resistivity however does enable partial penetration of the resonant field thus modifying the edge magnetic topology and characteristics of the edge transport. Plasma radial profiles undergo pronounced changes around the pedestal region, when the magnetic energy of the most unstable toroidal mode reaches the maximum value. Systematic scans of the applied RMP coil current with the JOREK simulations find a threshold value of around 4.5kAt required for achieving the ELM mitigation on HL-2A.

Comparison of isometric handgrip test among pregnant offspring of hypertensive parents and pregnant offspring of non-hypertensive parents.

A family history of hypertension is one of the important risk factors for the development of pregnancy-induced hypertension (PIH). Offspring of hypertensive parents should be screened for PIH. The isometric handgrip (IHG) test is used to assess autonomic function among them. Autonomic function dysregulation can indicate their predisposition to develop PIH later in the course of pregnancy. To compare the IHG among pregnant offspring of hypertensive parents (Group 1) and non-hypertensive parents (Group 2). This is a cross-sectional study done among 100 pregnant women in the second trimester (50 participants in each group). Blood pressure responses to sustained hand grip for 2 minutes of maximum voluntary contraction (MVC) were recorded, immediately at the end of the IHG test and after 5 minutes of the IHG test. Independent t-test and Mann-Whitney U test were used to compare the responses in two groups. There is no statistical difference in basal blood pressure and heart rate between the two groups. Group 1 exhibited a significant increase in systolic blood pressure (SBP) and diastolic blood pressure (DBP) compared to Group 2 immediately after 2 minutes of the IHG test. There is a significant increase in SBP after 5 minutes of the IHG in Group 2. Offspring of hypertensive parents have increased sympathetic reactivity and restoration of the blood pressure is significantly less compared to offspring of normotensive parents, which may predispose them for PIH. IHG can be applied as a convenient tool to screen the population who are at risk of PIH in places like primary health centres or field screenings where IHG is one possible option.

Sarcopenia and frailty among the elderly population in the community: An observational study.

There are few studies on the prevalence of sarcopenia and frailty in India. The aim of this study was to assess sarcopenia and frailty using simple clinical tools among the elderly population in the community. This was an observational study. The elderly population with an age group of >60 years residing in villages within 10-15 km of Sumandeep Vidyapeeth, Vadodara, formed the sampling frame of the study. A total of 785 participants were approached, of whom 556 were included in the study based on inclusion criteria. Participants were assessed for grip strength, muscle mass, gait speed, and frailty. The data were analyzed using STATA-IC statistical software version 13. A nonparametric Chi-square (χ2) test was used for categorical variables, and an independent-samples t-test was used to analyze the difference between various variables. Statistical significance was considered at P < 0.05 with a 95% confidence interval (CI). Based on the Indian criteria, 205 participants (36.1%) were diagnosed as having sarcopenia, and 351 participants (63%) were diagnosed as having "no sarcopenia." 5.6% of participants were found to be frail, 19.2% to be pre-frailty, and 75.2% to be no frailty. The χ2 analysis showed a significant association of sarcopenia with gender and different age groups (P value < 0.001). In this study, 36.9% of the elderly participants were found to have "sarcopenia," and 5.6% of the participants had frailty. Simple clinical tools used were easy to administer and suitable for field screening.

Effects of Different Shelling Methods on Data Variability during Field Screening for Reduced Aflatoxin Contamination in Maize.

Non-genetic variation limits the identification of novel maize germplasm with genetic markers for reduced Aspergillus flavus infection and aflatoxin contamination. Aflatoxin measurements can vary substantially within fields containing the same germplasm following inoculation with A. flavus. While some variation is expected due to microenvironmental differences, components of field screening methodologies may also contribute to variability in collected data. Therefore, the objective of this study is to test the effects of three different shelling methods (whole ear (WE), ear end removal (EER), and inoculation site-surrounding (ISS)) to obtain bulk samples from maize on aflatoxin measurements. Five ears per row of three inbred lines and two hybrids were inoculated with A. flavus, then shelled using the three different methods, and aflatoxin was quantified. Overall, EER and ISS resulted in reduced coefficients of variance (CVs) in comparison to WE for both inbred and hybrid maize lines, with two exceptions. Susceptible B73 showed increased CVs with both EER and ISS compared to WE, and resistant Mp719's EER CVs marginally increased compared to WE. While WE is the standard practice for most breeding programs due to its technical simplicity, EER and ISS may allow for finely phenotyping parental lines for further breeding applications.

Experimental Observation of Space-Charge Field Screening of a Relativistic Particle Bunch in Plasma.

The space-charge field of a relativistic charged bunch propagating in plasma is screened due to the presence of mobile charge carriers. We experimentally investigate such screening by measuring the effect of dielectric wakefields driven by the bunch in a uncoated dielectric capillary where the plasma is confined. We show that the plasma screens the space-charge field and therefore suppresses the dielectric wakefields when the distance between the bunch and the dielectric surface is much larger than the plasma skin depth. Before full screening is reached, the effects of dielectric and plasma wakefields are present simultaneously.

Small Stomates and Xylem Vessels Associated With Freeze Tolerance in Winter Barley

ABSTRACTFreeze tolerance is a complex agronomic trait that is difficult to evaluate in the field because of year‐to‐year variation in weather. Discovering plant characteristics closely related to freeze tolerance would enable more effective selection for this important trait. To explore possible physiological mechanisms and search for useful characteristics related to freeze tolerance in winter barley, we conducted field and growth chamber experiments with seven freeze‐tolerant and seven freeze‐susceptible genotypes that exhibited contrasting winter survival in preliminary field screenings. In a 2‐year field experiment, malondialdehyde, proline and water‐soluble carbohydrate concentrations were measured during cold acclimation and deacclimation to investigate differences in osmoregulation and membrane stability between freeze‐tolerant and freeze‐sensitive genotypes. All parameters varied by sampling year, and significant differences between freeze tolerance groups were found mainly during cold deacclimation in the spring. In growth chamber experiments, the size of xylem vessels and stomates was measured with and without cold acclimation. Freeze‐tolerant genotypes had smaller xylem vessels and stomates than freeze‐sensitive genotypes with and without cold acclimation, and small stomatal length was associated with a small xylem vessel area. Thus, it may be possible to improve freeze tolerance in winter barley by selecting smaller xylem and stomate cells. This study also validated germplasms of winter barley with differential freeze tolerance for future projects on breeding for improving winter hardiness and on plant physiology and genetics in response to freezing stress.

Measuring the Electric Fields of Ions Captured in Crown Ethers.

Controlling reactivity with electric fields is a persistent challenge in chemistry. One approach is to tether ions at well-defined locations near a reactive center. To quantify fields arising from ions, we report crown ethers that capture metal cations as field sources and a covalently bound vibrational Stark shift probe as a field sensor. We use experiments and computations in both the gas and liquid phases to quantify the vibrational frequencies of the probe and estimate the electric fields from the captured ions. Cations, in general, blue shift the probe frequency, with effective fields estimated to vary in the range of ∼0.2-3 V/nm in the liquid phase. Comparison of the gas and liquid phase data provides insight into the effects of mutual polarization of the molecule and solvent and screening of the ion's field. These findings reveal the roles of charge, local screening, and geometry in the design of tailored electric fields.

THz generation by AlGaAs/GaAs heterostructured p-i-n diode

The generation of terahertz radiation by heterostructure p-i-n AlxGa1−xAs/GaAs diodes excited by femtosecond optical pulses was studied experimentally and using the Monte Carlo method. It is shown that when the reverse bias varies, the terahertz generation mechanism changes. With a positive bias on the p-i-n diode, the THz generation mechanism is due to the reflection of the photoexcited electrons from the interface. With a large internal electric field, THz generation in the p-i-n diode occurs due to the acceleration of electrons at the ballistic stage of their movement in the electric field to velocities significantly exceeding the steady state velocity (“velocity overshoot”). The subsequent sharp decrease in velocity of electrons is associated with their inter-valley transitions from the Γ-valley to the L-valley of the conduction band. At electric fields less than 22 kV/cm, the effect of electric field screening by photoexcited carriers has a significant impact on the formation of photocurrent and, accordingly, on the THz generation mechanism. As the reverse bias decreases, this effect leads to a shift in the maximum of the THz pulse toward shorter times and it begins to dominate at electric fields less than 10 kV/cm.

Exploring Fusarium head blight resistance in a winter triticale germplasm collection

AbstractFusarium head blight (FHB; caused by Fusarium graminearum) is a destructive disease of wheat (Triticum spp.), barley (Hordeum vulgare), rye (Secale cereale L.), and triticale (×Triticosecale Wittmack) not only reducing their yield but also contaminating the grain with mycotoxins such as deoxynivalenol (DON). Developing varieties with genetic resistance is integral to successfully manage FHB. Triticale acreage worldwide is steadily increasing. However, the genetic diversity of triticale for FHB resistance is not well characterized. In the present study, a sequential screening of a set of winter triticale accessions from a global collection was done for their type‐2 FHB resistance and DON accumulation. In the first‐year screening, 298 triticale accessions were tested for FHB in an artificially inoculated, misted‐field nursery with high inoculum density. Most of the triticale accessions were susceptible to FHB, and only 8% of the accessions showed resistance in the field nursery screening. Next, the 24 resistant accessions identified in the nursery screening were tested for 2 years in greenhouse and 17 accessions showed significantly lower FHB severity in Year 2 and/or Year 3. These 17 resistant accessions were further tested for their FHB severity and DON accumulation in Year 4 in greenhouse and for DON accumulation in Year 5 in the field FHB nursery. Eight accessions showed significantly lower FHB severity and nine accessions showed DON accumulation of less than 1 mg/kg in Year 4 greenhouse testing. Eleven accessions had significantly lower DON concentration than the susceptible check in the Year 5 field screening. The resistant accessions common across all years identified in the study can be used for enhancing FHB resistance and reducing DON accumulation in triticale breeding programs.

Validity of LiPON Conductivity Determined by Impedance Spectroscopy

A hypothesis that the generally accepted value of the LiPON conductivity should be attributed to the absorption and displacement currents is substantiated. The reason is a small contribution of the drift current due to field screening by the electric double layer. The basis for this assumption is the measurement of the LiPON absorption capacitance, according to which its dielectric constant is about 106. An alternative equivalent circuit containing a non-ideal absorption element is proposed and its impedance is calculated. It is shown that the Bode diagrams of the alternative circuit approximate the experimental curves well. Parameters and the magnitude of electric field screening are calculated based on a proposed model of a double electric layer. Considering the screening effect, the drift conductivity of LiPON is obtained, which is in good agreement with the data on lithium concentration and ion mobility.

A Model for Pair Production Limit Cycles in Pulsar Magnetospheres

It was recently proposed that the electric field oscillation as a result of self-consistent e ± pair production may be the source of coherent radio emission from pulsars. Direct particle-in-cell simulations of this process have shown that the screening of the parallel electric field by this pair cascade manifests as a limit cycle, as the parallel electric field is recurrently induced when pairs produced in the cascade escape from the gap region. In this work, we develop a simplified time-dependent kinetic model of e ± pair cascades in pulsar magnetospheres that can reproduce the limit-cycle behavior of pair production and electric field screening. This model includes the effects of a magnetospheric current, the escape of e ±, as well as the dynamic dependence of pair production rate on the plasma density and energy. Using this simple theoretical model, we show that the power spectrum of electric field oscillations averaged over many limit cycles is compatible with the observed pulsar radio spectrum.

Evaluating the Reliability of 'AudiClick': A Click-Based Mobile App for Hearing Loss.

To develop and validate a click-based mobile "Audiclick" app employing click noises for hearing assessments. This prospective comparative study compares the "AudiClick" app as a hearing screening tool to pure tone audiometry. Participants listened to sounds through wired earbud headphones that were connected to an Android or iOS device. The study involved 110 participants aged between 18 to 80 years old. All degrees of hearing loss severity corresponds to pure tone average (p < 0.01) results. The app was also found to be effective at identifying hearing loss (80-99% sensitivity, specificity, positive predictive value, and accuracy). Test-retest reliability had also shown excellent ICC scores of 0.93. This study demonstrates that a mobile app using click sounds can be as efficient as pure tone audiometry for field screenings, while being more cost-effective and easier to develop.

Fundamental difference between the mechanisms of electrostatic field screening in dense and thoroughly collisionless plasmas

When an external electric field appears in a homogeneous plasma, ions move into regions where their electrostatic energy is lower. Simultaneously, forces arise that counteract this effect, causing the plasma to reach equilibrium when the field disappears completely. In collisional plasma, the resulting charge inhomogeneities decrease both Coulomb energy and entropy. Randomly induced diffusion flows tend to hinder their growth, minimizing free energy at any point. Accordingly, in the Debye–Hückel theory, the external field strength decreases exponentially with distance within the plasma. In a collisionless plasma, an antiscreening mechanism operates differently. Each ion moves in a self-consistent field along distinct trajectories, following classical dynamics laws. An external field bends these trajectories, bringing ions into regions where their Coulomb energy is lower. The antiscreening mechanism occurs when ions accelerate into potential wells, increasing the distances between them along their trajectories and decreasing their number densities along these paths. The law of energy conservation for any single ion governs this principally nonlocal process, and the dependence of field strength on distance is not necessarily exponential. This paper demonstrates that the Debye–Hückel theory should not be used to describe the charge density distribution within an unrestricted stream of collisionless plasma, such as the solar wind. It also analyzes non-exponential solutions of the Poisson equation for plasma sheaths above flat surfaces, from which such a flow takes off and on which it falls, obtained in quadratures.

On language development in the times of screen addiction (based on English neologisms)

The given article is the summary of the research into neologisms of the lexico-semantic field Screen Addiction, the aim of which is to describe ways and means of the formation of screen addiction neologisms in modern English following the tenets of the cognitive-discursive approach. The methods used in data analysis are the definition method, the componential and the discourse analysis, and quantitative methods. The data under study (31 neologisms) were collected from dictionaries and online sources (newspapers, blogs, etc.) by hand search. The analysis of the semantic structure of the language unit “screen” in diachronic perspective led us to the conclusion that this language unit is flexible as all ongoing social changes tend to be accompanied by the expansion of the lexico-semantic variants of “screen” and by the change of their hierarchical structure. At present the most active variants of “screen” are “display on a computer monitor” and “the monitor itself ”. The neologisms of the lexico-semantic field Screen Addiction were classified by structural and semantic parameters. By their structure, they fall into two groups – neologisms with and without the “screen” component. By the semantic parameter we mean those spheres of our life, which have been influenced by screen addiction and have found their reflection in neologisms. According to the semantic parameter, neologisms fall into several groups: а) time/epoch we live in; b) people living in these times; c) time spent in front of the screen; d) screen addiction and ways of tackling it; e) diseases and other dysfunctions caused by screen addiction; and f) behaviour and manners. Group d) (screen addiction and ways of solving this issue) takes the lead (61 % of neologisms) which can indicate that this very aspect is people’s utmost concern at present. In terms of word building, compound words prevail (81% neologisms), whereas neologisms built by blending are only 16%, and by suffixation − 3%. It can be assumed that suffixation is less productive than compounding and blending since it does not let the speaker manifest his linguistic creativity in Internet communication.

Optimization of electric field screening effect under EHV overhead transmission lines using hybrid computing CSM-GOA paradigm

Optimization of electric field screening effect under EHV overhead transmission lines using hybrid computing CSM-GOA paradigm

Exploring Host Resistance against Chilli Leaf Curl Disease in a Tolerant Chilli Genotype.

In tropical countries, combating leaf curl disease in hot peppers has become important in improvement programs. Leaf curl disease is caused by whitefly (Bemisia tabaci) transmitted begomoviruses, which mainly include chilli leaf curl virus (ChiLCV). However, multiple begomoviruses have also been found to be associated with this disease. The Capsicum annuum line, DLS-Sel-10, was found to be a tolerant source against this disease during field screening. In this study, we characterized the resistance of DLS-sel-10 against chilli leaf curl virus (ChiLCV) in comparison to the susceptible cultivar Phule Mukta (PM), focusing on the level, stage, and nature of resistance. Comprehensive investigations involved screening of DLS-Sel-10 against the whitefly vector ChiLCV. The putative tolerant line displayed reduced virus infection at the seedling stage, with increasing resistance during vegetative, flowering, and fruiting stages. Both DLS-Sel-10 and PM could be infected with ChiLCV, although DLS-Sel-10 remained symptomless. Insect feeding assays revealed DLS-Sel-10 as a less preferred host for whiteflies compared to PM. In conclusion, DLS-Sel-10 demonstrated tolerance not only to ChiLCV but also served as an unfavorable host for the whitefly vector. The study highlighted an age-dependent increase in tolerance within DLS-Sel-10, showcasing its potential for effective leaf curl disease management in chilli.