Mapping Of Resistance Research Articles

Age and Gender Related Variability in the Strength of Auricular Cartilage in Living Humans.

Despite previous studies on auricle morphology, research on its biomechanical properties remains limited. This study aims to assess age- and gender-related variations in auricle strength in living humans. A prospective, clinical study was conducted to assess auricle stiffness at three antihelix points (superior, middle, and inferior) using a digital Newton meter. Measurements were conducted in two modes to assess the force needed to move the auricle medially by 1, 2, 3, and 4mm, and the peak force required to displace the auricle medially to a distance of 1mm from the mastoid skin. Morphological measurements were also recorded to assess the auricle dimensions and projections at various levels of the auricle. Data were analyzed to examine age-related and gender-related distributions, as well as to investigate correlations between morphological parameters and resistance measurements. The study included 226 ears from 52 women and 61 men, aged 2-85 years. Age significantly influenced most anthropometric measurements, with males generally exhibiting larger ears. Resistance values increased with age, particularly in age groups over 35 and 50. Gender did not significantly affect resistance values. Positive correlations were found between auricle dimensions and resistance values, indicating increased resistance with increased auricle projection. This study provides a comprehensive mechanical resistance map of the auricle, demonstrating age-related changes in stiffness and regional variations in mechanical properties. These findings are valuable for refining surgical techniques, tissue engineering, and potentially for forensic applications. Further research on diverse populations and standardization of measurement protocols are recommended. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Identification of powdery mildew resistance quantitative trait loci in melon and development of resistant near-isogenic lines through marker-assisted backcrossing

BackgroundMelon (Cucumis melo L.), an important cucurbit crop, faces production limitations due to powdery mildew (PM). Developing resistant varieties offers a sustainable, genetics-based alternative to chemical treatments. Therefore, identifying PM resistance quantitative trait loci (QTL) and creating trait-associated markers are essential for efficient melon PM resistance improvement through marker-assisted backcrossing (MABC).ResultsThree F2 populations, A6, B2, and C4, were generated for QTL mapping of PM resistance. Major QTL were identified on chromosome 2 in A6, chromosome 5 in B2, and chromosomes 5 and 12 in C4. A series of TaqMan® assays targeting regions on chromosomes 2, 5, and 12 were developed and validated for foreground and recombinant selection, complemented by the double digest restriction-site associated DNA genotyping system to evaluate the recurrent parent genome recovery. Three MABC programs using resistant donor parents from A6 and C4 crossed with elite susceptible recurrent parents with green and orange fruit flesh were implemented. After two to three cycles of MABC, individual QTL was successfully introgressed into elite genetic backgrounds, giving six PM resistance lines in each green- and orange-fleshed background. PM inoculation on the twelve near-isogenic lines confirmed their resistance to PM.ConclusionsWe have identified major PM resistance QTL for melon on chromosomes 2, 5, and 12 and have introgressed individual QTL to elite genetic backgrounds using MABC in three and a half years. This study demonstrates the power of combining high-throughput genotyping with breeding efforts and showcases the efficiency of molecular breeding.

QTL mapping of adult plant resistance for leaf rust in F2:3 wheat pedigrees derived from Zhou mai 22/Chinese spring

QTL mapping of adult plant resistance for leaf rust in F2:3 wheat pedigrees derived from Zhou mai 22/Chinese spring

Geoelectrical resistivity mapping for sustainable groundwater management in Umuahia South: Insights from vertical electrical sounding

The study of geoelectrical resistivity provides critical insights into subsurface characteristics and aquifer dynamics, particularly in regions with varying geological formations. This research investigates the geoelectrical properties of the aquifer system in Umuahia South, highlighting its significance for sustainable groundwater management. The primary aim of this study is to characterize the geoelectrical layers, assess aquifer thickness and resistivity, and evaluate the implications for groundwater resource management. Vertical Electrical Sounding (VES) was conducted across ten locations to measure the resistivity and thickness of subsurface layers. The data collected were analyzed to identify distinct geoelectrical layers, their respective resistivity values, and thicknesses. The study reveals significant variations in aquifer properties across the region, with VES 1 showcasing the largest thickness of 69.2 m and VES 9 the smallest at 5.2 m. Aquifer thickness decreases from the Benin Formation toward the Ameki and Ogwashi-Asaba Formations. Hydraulic conductivity ranges from 0.207 to 0.954 m/day, indicating varying groundwater flow potential, while transmissivity values vary from 4.965 to 30.441 m²/day, with 60% of aquifers classified as intermediate. Groundwater Potential Index (GWPI) highlights approximately 70% of the area as high potential, underscoring the need for targeted management strategies to optimize water resource extraction and sustainability. The variability in resistivity and thickness across the study area suggests significant subsurface heterogeneity. High resistivity values indicate favorable conditions for groundwater flow, particularly in areas like VES 6. Conversely, lower resistivity in locations such as VES 9 indicates potential challenges for groundwater storage. This study provides vital information on the aquifer system in Umuahia South, emphasizing the need for targeted groundwater management strategies based on the geoelectrical characteristics identified. The research contributes to a deeper understanding of the aquifer dynamics in the region and offers a framework for sustainable groundwater resource management, highlighting the importance of geoelectrical assessments.

Identification of genes governing YMD resistance in soybean cultivar SL 958.

Yellow mosaic disease (YMD) is the most devastating disease of soybean under north Indian conditions. A recombinant inbred line population derived from SL 958 (R) × AGS 456 (S) was used to map the genes imparting YMD resistance. Genotyping by sequencing (GBS) of 148 individuals and the parents was used to identify polymorphic SNPs in the population. These were used to generate linkage maps and subsequently map the QTL. A QTL, MYMIV 1-1.1, was mapped onto chromosome 6. The QTL was mapped at a genetic distance of 114.31 cM, with likelihood ratio of 81.34 (LOD 17.68), explaining 33.80% of the variation for the trait, with an additive effect of 1.22. MYMIV 1-1.1 was flanked by SNPs Gm06_12614920 explaining 33.80% of variation and Gm06_12887789 explaining 31.04% of the variation. The QTL region spanned for a total of 2.798 Mbp. The QTL was mapped in an approximately 4 cM region. Flanking SNPs can be developed into linked markers for effective marker-assisted selection. Out of the genes in the QTL region, Glyma.06G161700 (Suppressor of Gene Silencing/SGS3) is the strongest contender for the resistance gene. This is the first study documenting GBS-based mapping of YMD resistance in soybean. © 2024 Society of Chemical Industry.

Introgression and Mapping of Cotton Leaf Curl Disease (CLCuD) Resistance from Wild Gossypium armourianum Kearney into Upland Cotton (G. hirsutum L.).

Cotton leaf curl disease (CLCuD), caused by the whitefly transmitted geminivirus complex (Cotton leaf curl virus - CLCuV and their satellite molecules), is a serious threat to successful upland cotton production in northwest India, Pakistan, and China. The disease causes significant losses in fibre yield and the quality of cotton. Owing to the regular emergence of resistance breaking strains of CLCuV, all the previously available CLCuD resistant germplasms of upland cotton have become compromised and none of the extant upland cotton cultivars is resistant to this disease. Therefore, alternate sources of CLCuD resistance need to be explored, as genetic resistance is the only pragmatic and tenable management strategy to combat this malady. Here, we report for the first time the introgression and mapping of CLCuD resistance from a related non-progenitor wild diploid D-genome cotton species, G. armourianum into upland cotton. A backcross population (G. hirsutum/G. armourianum/G. hirsutum) was developed for this purpose. A single major QTL was found to be associated with resistance to CLCuD and was located on chromosome D01 through the genotyping-by-sequencing technique.

QTL Mapping-Based Identification of Visceral White-Nodules Disease Resistance Genes in Larimichthys polyactis.

Disease outbreaks in aquaculture have recently intensified. In particular, visceral white-nodules disease, caused by Pseudomonas plecoglossicida, has severely hindered the small yellow croaker (Larimichthys polyactis) aquaculture industry. However, research on this disease is limited. To address this gap, the present study employed a 100K SNP chip to genotype individuals from an F1 full-sib family, identify single nucleotide polymorphisms (SNPs), and construct a genetic linkage map for this species. A high-density genetic linkage map spanning a total length of 1395.72 cM with an average interval of 0.08 cM distributed across 24 linkage groups was obtained. Employing post-infection survival time as an indicator of disease resistance, 13 disease resistance-related quantitative trait loci (QTLs) were detected, and these regions included 169 genes. Functional enrichment analyses pinpointed 11 candidate disease resistance-related genes. RT-qPCR analysis revealed that the genes of chmp1a and arg1 are significantly differentially expressed in response to P. plecoglossicida infection in spleen and liver tissues, indicating their pivotal functions in disease resistance. In summary, in addition to successfully constructing a high-density genetic linkage map, this study reports the first QTL mapping for visceral white-nodules disease resistance. These results provide insight into the intricate molecular mechanisms underlying disease resistance in the small yellow croaker.

Optimization of cooling process under varied pulsed conditions in multi-stage thermoelectric systems

This paper addresses the issue of thermoelectric cooling in a pulsed quasi-steady state (repetitive) condition. This situation occurs, for example, for an electronic integrated circuit performing demanding tasks in a discontinuous manner. Using heat reservoirs of selected capacity that are part of the thermoelectric system and appropriate shaping of the time profile of the supplied electrical current, cooling temperatures not achievable in the steady state for the system can be reached in a pulsed manner for a specified period. This process is subject to optimization. The analysis was carried out for a two-stage system with an internal (interstage) heat reservoir of a given thermal capacity. The aim of the study was to find the relationship between the level of the supercooling temperature, its repeatability and the ability to maintain this temperature for a given time. To this end, two supply current waveforms were adopted and optimized both without and with contact thermal resistance in the system. The lowest supercooling temperature of about 7 K lower than the steady-state temperature was obtained for a very long period and a very short holding time. Decreasing the period or increasing the holding time results in a non-linear increase in temperature. Similar effects are obtained for the contact thermal resistance present in each layer. A full map of the “period-thermal resistance–temperature” relationship was determined, as well as the supercooling potential curves.

Pangenomes of human gut microbiota uncover links between genetic diversity and stress response

The genetic diversity of the gut microbiota has a central role in host health. Here, we created pangenomes for 728 human gut prokaryotic species, quadrupling the genes of strain-specific genomes. Each of these species has a core set of a thousand genes, differing even between closely related species, and an accessory set of genes unique to the different strains. Functional analysis shows high strain variability associates with sporulation, whereas low variability is linked with antibiotic resistance. We further map the antibiotic resistome across the human gut population and find 237 cases of extreme resistance even to last-resort antibiotics, with a predominance among Enterobacteriaceae. Lastly, the presence of specific genes in the microbiota relates to host age and sex. Our study underscores the genetic complexity of the human gut microbiota, emphasizing its significant implications for host health. The pangenomes and antibiotic resistance map constitute a valuable resource for further research.

Characterization and Genetic Mapping of Resistance to Cotton–Melon Aphid (Aphis gossypii) in Cucumber

Characterization and Genetic Mapping of Resistance to Cotton–Melon Aphid (<scp><i>Aphis gossypii</i></scp>) in Cucumber

Resistivity as a Witness of Local Crystal Growth Conditions

A detailed knowledge of the growth front geometry during physical vapor transport (PVT) growth of SiC single crystals is beneficial to achieve high quality n+ SiC substrates for power device applications. In this report we show how mapping of resistivity in SiC wafers can shed light on local growth conditions, which are very difficult-to-study in situ. We consider both thermodynamic quantities (absolute temperature T and partial pressure pN₂) and geometric characteristics of the growth surface relevant to growth kinetic parameters, namely atomic terrace width and atomic step velocity. Specifically, we show how an elevation map of the growth surface can be reconstructed from a spatially-resolved measurement of resistivity in a SiC wafer by integrating the spatial derivative of elevation with respect to the basal plane, which is assumed to be related to local resistivity through dependence of non-equilibrium nitrogen incorporation on the atomic step velocity.

ResMAP-a saturation mutagenesis platform enabling parallel profiling of target-specific resistance-conferring mutations in Plasmodium.

An increase in treatment failures for malaria highlights an urgent need for new tools to understand and minimize the spread of drug resistance. We describe the development of a RESistance Mapping And Profiling (ResMAP) platform for the identification of resistance-conferring mutations in Plasmodium spp, the causative agent of malaria. Saturation mutagenesis was used to generate a mutation library containing all conceivable mutations for a region of the antimalarial-binding site of a promising drug target, Plasmodium falciparum lysyl tRNA synthetase (PfKRS). Screening of this high-coverage library with characterized PfKRS inhibitors revealed multiple resistance-conferring substitutions including several clinically relevant mutations. Genetic validation of these mutations confirmed resistance of up to 100-fold and computational modeling dissected their role in drug resistance. We discuss potential applications of this data including the potential to design compounds that can bypass the most serious resistance mutations and future resistance surveillance.

Fine mapping of stem rust resistance derived from soft red winter wheat cultivar AGS2000 to an NLR gene cluster on chromosome 6D

The Puccinia graminis f. sp. tritici (Pgt) Ug99-emerging virulent races present a major challenge to global wheat production. To meet present and future needs, new sources of resistance must be found. Identification of markers that allow tracking of resistance genes is needed for deployment strategies to combat highly virulent pathogen races. Field evaluation of a DH population located a QTL for stem rust (Sr) resistance, QSr.nc-6D from the breeding line MD01W28-08-11 to the distal region of chromosome arm 6DS where Sr resistance genes Sr42, SrCad, and SrTmp have been identified. A locus for seedling resistance to Pgt race TTKSK was identified in a DH population and an RIL population derived from the cross AGS2000 × LA95135. The resistant cultivar AGS2000 is in the pedigree of MD01W28-08-11 and our results suggest that it is the source of Sr resistance in this breeding line. We exploited published markers and exome capture data to enrich marker density in a 10 Mb region flanking QSr.nc-6D. Our fine mapping in heterozygous inbred families identified three markers co-segregating with resistance and delimited QSr.nc-6D to a 1.3 Mb region. We further exploited information from other genome assemblies and identified collinear regions of 6DS harboring clusters of NLR genes. Evaluation of KASP assays corresponding to our co-segregating SNP suggests that they can be used to track this Sr resistance in breeding programs. However, our results also underscore the challenges posed in identifying genes underlying resistance in such complex regions in the absence of genome sequence from the resistant genotypes.

Association mapping of tan spot and septoria nodorum blotch resistance in cultivated emmer wheat.

A total of 65 SNPs associated with resistance to tan spot and septoria nodorum blotch were identified in a panel of 180 cultivated emmer accessions through association mapping Tan spot and septoria nodorum blotch (SNB) are foliar diseases caused by the respective fungal pathogens Pyrenophora tritici-repentis and Parastagonospora nodorum that affect global wheat production. To find new sources of resistance, we evaluated a panel of 180 cultivated emmer wheat (Triticum turgidum ssp. dicoccum) accessions for reactions to four P. tritici-repentis isolates Pti2, 86-124, 331-9 and DW5, two P. nodorum isolate, Sn4 and Sn2000, and four necrotrophic effectors (NEs) produced by the pathogens. About 8-36% of the accessions exhibited resistance to the four P. tritici-repentis isolates, with five accessions demonstrating resistance to all isolates. For SNB, 64% accessions showed resistance to Sn4, 43% to Sn2000 and 36% to both isolates, with Spain (11% accessions) as the most common origin of resistance. To understand the genetic basis of resistance, association mapping was performed using SNP (single nucleotide polymorphism) markers generated by genotype-by-sequencing and the 9K SNP Infinium array. A total of 46 SNPs were significantly associated with tan spot and 19 SNPs with SNB resistance or susceptibility. Six trait loci on chromosome arms 1BL, 3BL, 4AL (2), 6BL and 7AL conferred resistance to two or more isolates. Known NE sensitivity genes for disease development were undetected except Snn5 for Sn2000, suggesting novel genetic factors are controlling host-pathogen interaction in cultivated emmer. The emmer accessions with the highest levels of resistance to the six pathogen isolates (e.g., CItr 14133-1, PI 94634-1 and PI 377672) could serve as donors for tan spot and SNB resistance in wheat breeding programs.

Genetic mapping of stripe rust resistance in a geographically diverse barley collection and selected biparental populations.

Barley stripe or yellow rust (BYR) caused by Puccinia striiformis f. sp. hordei (Psh) is a significant constraint to barley production. The disease is best controlled by genetic resistance, which is considered the most economical and sustainable component of integrated disease management. In this study, we assessed the diversity of resistance to Psh in a panel of international barley genotypes (n = 266) under multiple disease environments (Ecuador, India, and Mexico) using genome-wide association studies (GWASs). Four quantitative trait loci (QTLs) (three on chromosome 1H and one on 7H) associated with resistance to Psh were identified. The QTLs were validated by mapping resistance to Psh in five biparental populations, which detected key genomic regions on chromosomes 1H (populations Pompadour/Zhoungdamei, Pompadour/Zug161, and CI9214/Baudin), 3H (Ricardo/Gus), and 7H (Fumai8/Baronesse). The QTL RpshQ.GWA.1H.1 detected by GWAS and RpshQ.Bau.1H detected using biparental mapping populations co-located were the most consistent and stable across environments and are likely the same resistance region. RpshQ.Bau.1H was saturated using population CI9214/Baudin by enriching the target region, which placed the resistance locus between 7.9 and 8.1 Mbp (flanked by markers sun_B1H_03, 0.7 cM proximal to Rpsh_1H and sun_B1H_KASP_02, 3.2 cM distal on 1HS) in the Morex reference genome v.2. A Kompetitive Allele Specific PCR (KASP) marker sun_B1H_KASP_01 that co-segregated for RpshQ.Bau.1H was developed. The marker was validated on 50 Australian barley cultivars, showing well-defined allelic discrimination and presence in six genotypes (Baudin, Fathom, Flagship, Grout, Sakurastar, and Shepherd). This marker can be used for reliable marker-assisted selection and pyramiding of resistance to Psh and in diversifying the genetic base of resistance to stripe rust.

Remote Detection of Leakages from a Compromised Buried Water Supply Pipe through Geophysical Measurements

The continuous drastic loss of stored water at a private household presumed to be caused by leakage(s) was subjected to geophysical investigations with a view to delineating the source(s) of the leakage(s). The Spontaneous Potential (SP) and Electrical Resistivity (ER) methods were deployed for the study. Measurements were taken along four (4) traverses at two intervals – firstly when the water supply valve from the overhead storage tank was closed and secondly when it was opened. The Total Field array was adopted for SP measurements with constant station separation of 0.5 m. ER measurements were taken via the Wenner array with electrode spacing (a) varied with an interval of 0.5 m from 0.5 m to 1.5 m. SP data were presented as profiles and maps while ER data were presented as 3-D resistivity depth stacks. SP values varied from -100 mV to 350 mV during the two measurement periods. ER values also varied from 100 ohm.m to 1200 ohm.m during the closed valve period and 100 ohm.m to 900 ohm.m during the opened valve period. During the closed valve period, pipeline routes were interpreted as manifesting oval-shaped high potential anomalies with central linear trend on the SP map; and as linearly-trending high resistivity intrusion within low resistivities on resistivity maps. The disparities between the results of closed valve and opened valve measurements were pointers to leakage-induced inhomogeneity in the subsurface. The diminished high potential SP anomaly and the anomalously low resistivity specks within linearly-trending high resistivity values were regarded as the source of leakage.

Electrochemical impedance spectroscopy analysis and thermal mapping of different cross-sectional cathode channels in open-cathode polymer electrolyte membrane fuel cell stack

The Electrochemical impedance spectroscopy (EIS) of three novel cathode channels designs square, boot, and triangular for open cathode polymer electrolyte cathode fuel cell stacks are analyzed. Fundamental mechanisms such as oxygen reduction reaction, proton conductivity, bulk resistance of stack, capacitance and structure features of the porous carbon electrode etc. are investigated with the help of Nyquist/Bode plots and Randles circuit. Operational parameters including airflow rate, current, H2 gas condition (humidified and dry), and stack temperature are studied focused on understanding the trend of high and low frequency resistance. The minimum resistance and temperature mapping for cross-section designs at different operating conditions is utilized for parametric optimization. Overall, it is recommended to operate the stacks at minimum resistance obtained just before the peak power density and its corresponding temperature ∼40 °C. Finally, a data-driven hybrid model integrating EIS and artificial intelligence is presented with root mean square error of ∼0.98.

QTL mapping of downy mildew resistance in foxtail millet by SLAF‑seq and BSR-seq analysis.

Key message Three major QTLs for resistance to downy mildew were located within an 0.78 Mb interval on chromosome 8 in foxtail millet. Downy mildew, a disease caused by Sclerospora graminicola, is a serious problem that jeopardizes the yield and quality of foxtail millet. Breeding resistant varieties represents one of the most economical and effective solutions, yet there is a lack of molecular markers related to the resistance. Here, a mapping population comprising of 158 F6:7 recombinant inbred lines (RILs) was constructed from the crossing of G1 and JG21. Based on the specific locus amplified fragment sequencing results, a high-density linkage map of foxtail millet with 1031 bin markers, spanning 1041.66 cM was constructed. Based on the high-density linkage map and the phenotype data in four environments, a total of nine quantitative trait loci (QTL) associated with resistance to downy mildew were identified. Further BSR-seq confirmed the genomic regions containing the potential candidate genes related to downy mildew resistance. Interestingly, a 0.78-Mb interval between C8M257 and C8M268 on chromosome 8 was highlighted because of its presence in three major QTL, qDM8_1, qDM8_2, and qDM8_4, which contains 10 NBS-LRR genes. Haplotype analysis in RILs and natural population suggest that 9 SNP loci on Seita8G.199800, Seita8G.195900, Seita8G.198300, and Seita.8G199300 genes were significantly correlated with disease resistance. Furthermore, we found that those genes were taxon-specific by collinearity analysis of pearl millet and foxtail millet genomes. The identification of these new resistance QTL and the prediction of resistance genes against downy mildew will be useful in breeding for resistant varieties and the study of genetic mechanisms of downy mildew disease resistance in foxtail millet.

Geoelectrical characterization of non-filled active faults in Jaral de Berrios, Guanajuato, México

Electromagnetic and electrical methods have a great number of applications and have become a commonly used tool for the study of active geological faults, where they are usually detected as low resistivity anomalies. However, this is not always the case. We used both Electromagnetic Profiling (EMP) and Electrical Resistivity Tomography (ERT) methods with the aim of mapping active geological faults which affect agricultural plots and a former quarry near the town of Jaral de Berrios, State of Guanajuato. The apparent resistivity map derived from EMP survey shows how NW-SE on site measured faults (which reach at least 400 m in length and 0.4 m in width) match with high apparent resistivity anomalies. Two ERT profiles reveal the subsurface continuity of the main fault zones, as well as the main high apparent resistivity lineaments, for at least 40 m below the surface. The resistive lineaments in the apparent resistivity map showed a coincidence with the faults modeled in the geoelectric section of the ERT1 profile; this result gives reliability to the methodology used in the study site. All of this means that faulting presently evident on the surface continues at depth and has a wider extension than previously thought, and that since the fractures are non-filled with minerals and/or moisture the preponderance of high resistivity anomalies make sense. The results of this work provide the basis for future studies that help in determining the type of faulting affecting our study area, so long term urban planning and development in the area may be possible.

In-situ resistance mapping of surface corrosion of iron using contact-mode carbon fibre as potentiometric tip

Scanning Probe Microscopy (SPM) has recently gained significant attention from both scientists and engineers for its unique capability to investigate localized corrosion phenomena. This paper introduces a novel application of SPM that offers a unique in-situ means to quantitatively evaluate the resistance of a spontaneously formed oxide layer on the conductive surface of an uncoated iron sample. This approach involved rastering a thin carbon fibre on the iron sample immersed on a corrosive medium while maintaining direct contact between the tip of the carbon fibre and the studied surface. Depending on the resistance between the tip and the sample, the measured voltage proportionally varied between 0 and the potential of the potentiometric circuit formed by the iron sample, the electrolyte and the carbon fibre. Through the application of the voltage divider formula, the measured potential map was transformed into a resistance map. This process allowed us to render a visual representation of the resistance distribution across the surface of the iron sample, providing some insights into the properties of the oxide layer.