Performance Assessment of a Typical Range Hood Ventilation System

This study assessed the real-world performance of a typical range-hood ventilation system by focusing on parameters such as duct pressure drop and range hood capture efficiency. The research can be divided into two parts, mathematical modeling and laboratory testing. For example, the pressure drop through a typical range hood ducting system and the capture efficiency of under-cabinet range hoods were modeled individually. For laboratory testing, the range hood was experimentally tested in two ducting configurations representing two typical installation strategies found in practice, namely flexible and rigid ducts exiting through walls and ceilings. The bulk of the effort in this project was the experimental phase, and it could be divided into a Case 1 and Case 2. In Case 1 three different lengths of flexible duct (32”, 46”, 75”) and five different lengths of rigid duct (32”, 46”, 75”119”, 148”) were mounted so as to exit a sidewall. In Case 2, rigid duct was vented through the roof by using the same duct lengths tested in Case 1. Pressure drops through the duct and vent cap were measured at different fan speed levels to produce system performance curves. These curves were overlaid with measured fan curves to find operating points (i.e. flow rate, and pressure drop) that represent real-world range-hood ventilation systems. This study provides the basis for system performance assessments and system design recommendations. The results of this study showed that the pressure drop through flexible ducting is larger than the pressure drop through rigid ducting of same length. The increased static pressure drop in flexible ducting had a negative impact on range hood performance, which results in a lower airflow rate and capture efficiency. By comparing the predicted and the actual results, it was found that the pressure drop measured in the experimental test is higher than that predicted by the mathematical model, which needs to be taken into consideration in future designs. For capture efficiencies, it was found that they do not differ much for different duct lengths in the same configuration. At the same fan speed, rigid-duct range hood systems have higher capture efficiencies compared to flexible-duct range hood systems. Furthermore fan speeds have the largest effect on capture efficiencies, with values varying from 75% to 95% for fan speeds varying from low to high

Constructing Physical and Genomic Maps for Puccinia striiformis f. sp. tritici, the Wheat Stripe Rust Pathogen, by Comparing Its EST Sequences to the Genomic Sequence of P. graminis f. sp. tritici, the Wheat Stem Rust Pathogen

The wheat stripe rust fungus, Puccinia striiformis f. sp. tritici (Pst), does not have a known alternate host for sexual reproduction, which makes it impossible to study gene linkages through classic genetic and molecular mapping approaches. In this study, we compared 4,219 Pst expression sequence tags (ESTs) to the genomic sequence of P. graminis f. sp. tritici (Pgt), the wheat stem rust fungus, using BLAST searches. The percentages of homologous genes varied greatly among different Pst libraries with 54.51%, 51.21%, and 13.61% for the urediniospore, germinated urediniospore, and haustorial libraries, respectively, with an average of 33.92%. The 1,432 Pst genes with significant homology with Pgt sequences were grouped into physical groups corresponding to 237 Pgt supercontigs. The physical relationship was demonstrated by 12 pairs (57%), out of 21 selected Pst gene pairs, through PCR screening of a Pst BAC library. The results indicate that the Pgt genome sequence is useful in constructing Pst physical maps

Analysis on spatial heterogeneity of ecological restoration demand in resource-based cities: taking Jiawang District of Xuzhou city as an example

After a long period of coal resource exploitation in resource-based cities, the imbalance and disharmony between resource development and ecological protection in coal mining areas are prominent. In the context of ecological civilization construction, clarifying the spatial heterogeneity of ecological restoration needs and reasonably arranging the priority of ecological restoration work will become the basic work for efficient and coordinated ecological protection and restoration, which will help to plan as a whole, coordinate and orderly promote the high-quality sustainable development of resource-based cities. From the comprehensive perspective of the coordinated development of ecosystem and human well-being, Jiawang District, Xuzhou City, was selected as an example, and the historical remote sensing images, historical mine information and social and economic statistics in 2000, 2010 and 2019 were taken as the data sources. The equivalent assignment method was used to calculate the regional ecosystem service value and make coefficient correction. The landscape ecological risk assessment system was constructed by integrating the topographic location index, mining area disturbance index and landscape vulnerability index. The spatial and temporal patterns of ecosystem service value and ecological risk index in the study area were analyzed, and the sharpe ratio was introduced to further explore the spatial heterogeneity of ecological restoration needs. The results showed that: ① From 2000 to 2019, the total value of ecosystem services in Jiawang district increased first and then decreased, and the value of ecological risk index decreased first and then increased. The growth rate was relatively flat, showing a small range; the spatial distribution of ecological service value and ecological risk level shows a trend of overall connectivity, with local circles moving outward. Urbanization and coal mining subsidence land management are the main factors influencing the spatial pattern differentiation. ② At the quantitative level, the ecosystem service value per unit area and the ecological risk index have strong negative grade correlations, but there is no obvious functional relationship; At the spatial level, the overall Moran’s I index of unit ecosystem service value and ecological risk index in Jiawang District from 2000 to 2019 were negative, showing negative spatial correlation. Ecological risks and ecosystem services have obvious dislocation characteristics. ③ The heterogeneity index R of ecological restoration demand in Jiawang district presents a gradient spatial change trend to a certain extent, and the overall ecological restoration demand tends to decrease, but the R index is still too high or too low in some regions; with the increase of degree of deviation, the range of high value areas for ecological restoration needs gradually narrowed and transformed to low value areas, and the areas requiring key ecological construction tend to be more centralized. The research conclusion can provide reference for the decision-making arrangement of systematic and integrated ecological restoration of resource exhausted cities

An ancestral NB-LRR with duplicated 3'UTRs confers stripe rust resistance in wheat and barley.

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a global threat to wheat production. Aegilops tauschii, one of the wheat progenitors, carries the YrAS2388 locus for resistance to Pst on chromosome 4DS. We reveal that YrAS2388 encodes a typical nucleotide oligomerization domain-like receptor (NLR). The Pst-resistant allele YrAS2388R has duplicated 3' untranslated regions and is characterized by alternative splicing in the nucleotide-binding domain. Mutation of the YrAS2388R allele disrupts its resistance to Pst in synthetic hexaploid wheat; transgenic plants with YrAS2388R show resistance to eleven Pst races in common wheat and one race of P. striiformis f. sp. hordei in barley. The YrAS2388R allele occurs only in Ae. tauschii and the Ae. tauschii-derived synthetic wheat; it is absent in 100% (n = 461) of common wheat lines tested. The cloning of YrAS2388R will facilitate breeding for stripe rust resistance in wheat and other Triticeae species

Genome-wide QTL mapping for stripe rust resistance in spring wheat line PI 660122 using the Wheat 15K SNP array

IntroductionStripe rust is a global disease of wheat. Identification of new resistance genes is key to developing and growing resistant varieties for control of the disease. Wheat line PI 660122 has exhibited a high level of stripe rust resistance for over a decade. However, the genetics of stripe rust resistance in this line has not been studied. A set of 239 recombinant inbred lines (RILs) was developed from a cross between PI 660122 and an elite Chinese cultivar Zhengmai 9023.MethodsThe RIL population was phenotyped for stripe rust response in three field environments and genotyped with the Wheat 15K single-nucleotide polymorphism (SNP) array.ResultsA total of nine quantitative trait loci (QTLs) for stripe rust resistance were mapped to chromosomes 1B (one QTL), 2B (one QTL), 4B (two QTLs), 4D (two QTLs), 6A (one QTL), 6D (one QTL), and 7D (one QTL), of which seven QTLs were stable and designated as QYrPI660122.swust-4BS, QYrPI660122.swust-4BL, QYrPI660122.swust-4DS, QYrPI660122.swust-4DL, QYrZM9023.swust-6AS, QYrZM9023.swust-6DS, and QYrPI660122.swust-7DS. QYrPI660122.swust-4DS was a major all-stage resistance QTL explaining the highest percentage (10.67%–20.97%) of the total phenotypic variation and was mapped to a 12.15-cM interval flanked by SNP markers AX-110046962 and AX-111093894 on chromosome 4DS.DiscussionThe QTL and their linked SNP markers in this study can be used in wheat breeding to improve resistance to stripe rust. In addition, 26 lines were selected based on stripe rust resistance and agronomic traits in the field for further selection and release of new cultivars

Genome-wide association study of common resistance to rust species in tetraploid wheat

Rusts of the genus Puccinia are wheat pathogens. Stem (black; Sr), leaf (brown; Lr), and stripe (yellow; Yr) rust, caused by Puccinia graminis f. sp. tritici (Pgt), Puccinia triticina (Pt), and Puccinia striiformis f. sp. tritici (Pst), can occur singularly or in mixed infections and pose a threat to wheat production globally in terms of the wide dispersal of their urediniospores. The development of durable resistant cultivars is the most sustainable method for controlling them. Many resistance genes have been identified, characterized, genetically mapped, and cloned; several quantitative trait loci (QTLs) for resistance have also been described. However, few studies have considered resistance to all three rust pathogens in a given germplasm. A genome-wide association study (GWAS) was carried out to identify loci associated with resistance to the three rusts in a collection of 230 inbred lines of tetraploid wheat (128 of which were Triticum turgidum ssp. durum) genotyped with SNPs. The wheat panel was phenotyped in the field and subjected to growth chamber experiments across different countries (USA, Mexico, Morocco, Italy, and Spain); then, a mixed linear model (MLM) GWAS was performed. In total, 9, 34, and 5 QTLs were identified in the A and B genomes for resistance to Pgt, Pt, and Pst, respectively, at both the seedling and adult plant stages. Only one QTL on chromosome 4A was found to be effective against all three rusts at the seedling stage. Six QTLs conferring resistance to two rust species at the adult plant stage were mapped: three on chromosome 1B and one each on 5B, 7A, and 7B. Fifteen QTLs conferring seedling resistance to two rusts were mapped: five on chromosome 2B, three on 7B, two each on 5B and 6A, and one each on 1B, 2A, and 7A. Most of the QTLs identified were specific for a single rust species or race of a species. Candidate genes were identified within the confidence intervals of a QTL conferring resistance against at least two rust species by using the annotations of the durum (cv. ‘Svevo’) and wild emmer wheat (‘Zavitan’) reference genomes. The 22 identified loci conferring resistance to two or three rust species may be useful for breeding new and potentially durable resistant wheat cultivars

Rural Settlement Development in Western China: Risk, Vulnerability, and Resilience

Rural development is an essential link in the social governance system, and it is the key to market rural development and enhancing farmers’ living conditions. It is a critical starting point for changing the agricultural landscape and improving agricultural social governance capability. It is also the proper means of encouraging the balanced growth of urban and rural society, as well as traditional wealth. Farmers no longer have to worry about “short of food and clothing,” but “housing challenges” pose a threat to the soundness, harmony, and growth of rural areas, social hazards are increasing, and rural areas in distant western areas continue to create risk and vulnerability of living setting. Most previous studies have focused on economic and regulatory elements; however, this study focuses on the composition of home environment risk factors, as well as the influence of fabric vulnerability, trust vulnerability, and emotional vulnerability produced by risks. To successfully resist residential surroundings threats, improving the effectiveness of risk response and boosting farmers’ resilience are all critical strategies to reduce susceptibility. This study, which employs in-depth interview methodology, explains how the growth of a gorgeous new country must enhance and ensure the safety of farmers’ living surroundings to prevent risk impact, as well as how the country’s resilience should be improved. The findings indicate that, in the technique of rural government, the preservation of living environments is not only one of the primary desires of farmers, but, furthermore, the key to increasing farmers’ flexibility to combat hazards, and also the lone way to come through property rural development. In accordance with the specific situation, the associated countermeasures, square measure, imply: to begin, the highest body’s role placement is treated to weaken the fabric, this weakness caused by the unclear role positioning. Second, we should always encourage excellent communication among subjects about the concept of trust in order to reduce the vulnerability of trust produced by insufficient policy coverage and differences in policy interpretation and knowledge. Third, we should always perceive and satisfy the emotional needs of farmers’ families in order to reduce the emotional vulnerability caused by policies and procedures that neglect their true feelings

Construction and characterization of a full-length cDNA library for the wheat stripe rust pathogen

Puccinia striiformis is a plant pathogenic fungus causing stripe rust, one of the most important diseases on cereal crops and grasses worldwide. However, little is know about its genome and genes involved in the biology and pathogenicity of the pathogen. We initiated the functional genomic research of the fungus by constructing a full-length cDNA and determined functions of the first group of genes by sequence comparison of cDNA clones to genes reported in other fungi

Transcriptome analysis of the wheat-Puccinia striiformis f. sp. tritici interaction

Stripe rust [caused by Puccinia striiformis Westend. f. sp. tritici Eriks. (Pst)] is a destructive disease of wheat (Triticum aestivum L.) worldwide. Genetic resistance is the preferred method for control and the Yr5 gene, originally identified in Triticum spelta var. album, represents a major resistance (R) gene that confers all-stage resistance to all currently known races of Pst in the United States. To identify transcripts associated with the Yr5-mediated incompatible interaction and the yr5-compatible interaction, the Wheat GeneChip was used to profile the changes occurring in wheat isolines that differed for the presence of the Yr5 gene after inoculation with Pst. This time-course study (6, 12, 24 and 48 h post-inoculation) identified 115 transcripts that were induced during the R-gene-mediated incompatible interaction, and 73 induced during the compatible interaction. Fifty-four transcripts were induced in both interactions and were considered as basal defence transcripts, whilst 61 transcripts were specific to the incompatible interaction [hypersensitive response (HR)-specific transcripts] and 19 were specific to the compatible interaction (biotrophic interaction-specific transcripts). The temporal pattern of transcript accumulation showed a peak at 24 h after infection that may reflect haustorial penetration by Pst at ~16 h. An additional 12 constitutive transcript differences were attributed to the presence of Yr5 after eliminating those considered as incomplete isogenicity. Annotation of the induced transcripts revealed that the presence of Yr5 resulted in a rapid and amplified resistance response involving signalling pathways and defence-related transcripts known to occur during R-gene-mediated responses, including protein kinase signalling and the production of reactive oxygen species leading to a hypersensitive response. Basal defence also involved substantial induction of many defence-related transcripts but the lack of R-gene signalling resulted in weaker response