bluuebunny/crossref_metadata_2025 huggingface dataset:
The Turn and Change of Chinese Contemporary Oil Painting Patterns
Authors: Yang Jinjing , Chen Lan
Published: January 2022

Oil painting in China's local development breaks the shackles of traditional formal language and further highlights the innovation and turn of oil painting's iconography. This paper will focus on the rebellion of pictorial vision against tradition, the widening of the boundaries of vision and how pictorial personality uses the medium.
National Music Promotion and Inheritance Strategies Based on the Perspective of Intangible Cultural Heritage
Authors: Kang Lu
Published: January 2022

Folk music is a heavy cultural carrier. Today, when culture is flourishing, it still has a unique charm and appeal. The intangible heritage of national music requires modern Chinese to continue to carry forward and inherit it, so that the spirit and characteristic culture contained in it can be smoothly transformed into the fruits of education. For this reason, it will be a feasible idea to promote and inherit national music from the perspective of intangible cultural heritage with academies education as the central medium. The article combines the understanding of intangible cultural heritage and the thinking on the promotion and inheritance of ethnic music from the perspective of intangible heritage, and further explores the significance and strategy of the promotion and inheritance of ethnic music centered on vocal music teaching in colleges and universities, hoping to provide valuable reference for relevant research.
Investigation and Research on the Current Situation of Tai'an High School Basketball Team
Authors: Ma Zhaofeng , Qin Li
Published: January 2022

Basketball is a very popular sport. China's campus basketball, basketball training, national fitness basketball and other programs system is perfect, the number of games and participation is increasing. Tai'an City as shandong province high school basketball development leader has a certain representative, therefore, this paper on the status of Tai'an high school basketball team investigation and research, and put forward some suggestions, in order to provide some valuable basis for the development of Tai'an high school basketball team.
Analysis on Periodic Fluctuation of Economy at County Level
Authors: Zhang Bing
Published: January 2022

On most occasions, economic development is embodied with periodic characteristics. Comprehensive understanding of the economic cycle is of great significance to guiding the formulation of macroeconomic policies and maintaining stable economic growth. Since the reform and opening up, Tengzhou's economy has maintained a momentum of rapid growth, which, however, is characterized by obvious periodic fluctuations. This paper makes an in-depth analysis of the characteristics and causes of economic periodic fluctuation in Tengzhou, in order to have a comprehensive understanding of the economic cycle, and the economic law is adopted to take corresponding economic growth measures in different periods of economic development, thus achieving high-quality economic development. In this paper, the study of county economic cycle is not subject to economic theory, rather the study is conducted with a large number of historical background and local economic development characteristics. The economy of Tengzhou City, since the reform and opening up, is divided into five cycles. The conclusion is drawn that the county economic cycle is affected by macroeconomic fluctuations, industrial structure adjustment, investment and consumption fluctuations and other factors. We put forward targeted suggestions on using the economic cycle to promote high-quality economic development.
Historical Changes of Regulation and Competition in British Railway System
Authors: Zhao Hanyu
Published: January 2022

This article is based on the history of British railway reform, combined with related theories and policies, and explored what kind of regulatory policies should be adopted in what kind of economic environment.
Study on the Factors Influencing Total Health Cost Based on Multiple Regression Model
Authors: Zu Xiaoduo , Fang Jun
Published: January 2022

In recent years, China's social economy and income level of residents have increased rapidly, the total cost of health has increased rapidly, and the level of medical expenditure of residents has been increasing. This paper establishes a multivariate linear regression model using data from 1996 to 2020, and analyzes several important influencing factors that affect overall health expenditure. The aim is to formulate a health financing policy suitable for the coordinated development of China's social economy, and to provide a basis for adapting to the needs of economic development, structural adjustment and institutional transformation.
Analysis on the Development Potential of Bilateral Trade Cooperation between China and Uzbekistan
Authors: Zhao Rong
Published: January 2022

The economic and trade cooperation between China and Uzbekistan has been continuously strengthened. China is Uzbekistan's largest trading partner. In order to better promote the development of Sino-Uzbek relations, this article analyzes the current situation of Sino-Uzbek bilateral trade development. In this regard, it puts forward suggestions on promoting bilateral exchanges and so on, in order to seek a broader space for cooperation between the two countries.
PENGARUH BLENDED LEARNING BERBASIS COOPERATIVE LEARNING PADA PERKEMBANGAN KOGNITIF ANAK USIA DINI
Authors: Fikri M.Tsaqibul , Hidayah
Published: January 2022

The blended learning model based on cooperative learning can be an alternative in developing early childhood cognitive, using a variety of interesting activities so that children are able to solve problems creatively. This study aims to analyze the significance of the effect of the cooperative learning-based blended learning model on the cognitive development of children aged 3-4 years. The method used in this study is Pre-experimental with a one-group pretest-posttest design. This research was carried out at KB Al Hikmah, Cengkong Village, Parengan District, Tuban Regency. The time to carry out this research is on 25-27 February 2021. The population in this study amounted to 18 children. The sampling technique used was non-probability sampling. The data collection technique of this research used observation and documentation. The data analysis technique used table analysis, non-parametric uni analysis and simple linear regression test. The results of this study indicate that there is an effect of the blended learning model based on cooperative learning on the cognitive development of children aged 3-4 years before being given blended learning activities and after being given blended learning activities.
Analisis Mekanisme Akad Rahn, Qardh dan Ijarah Pada Produk Pembiayaan Mitra Emas IB Maslahah
Authors: Khairunnisa Alya , Joni Joni
Published: January 2022

Pawn included on one of the product financing in islamic banking. Bank BJB Syariah KCP Ciamis there is a product financing Gold Partner iB Maslahah. As known whether the mechanism of the contract that exists on the financing product Gold Partner iB Maslahah is in accordance with theory and existing regulations or not. The formulation of this research problem was how the mechanism akad rahn, qardh and finance on finance products Gold Partner iB Maslahah which is run by BJB Syariah KCP Ciamis. The method used in this research is descriptive method with qualitative approach. This study also uses two data sources, namely primary and secondary sources. The technique of data collection is done by observation, interview, and documentation. Data analysis techniques used are data reduction, data presentation, and clonclusioan drawing/verification. Based on the research results obtained the conclusion that the mechanism of akad rahn, qardh, and finance in the financing Gold Partner iB Maslahah that the mechanism of each contract already well underway, with a wide Gold Partner iB Maslahah itself can facilitate customers who wish to borrow money quickly and it takes time. In the process of redemption of any bank to do it carefully and in accordance with the operational standards that exist. The Bank does not give excess or deficiency in the funds of the loan given to the customer.
Biological Control of Postharvest Diseases of Citrus and Deciduous Fruit
Authors: Wilson Charles , Chalutz Edo
Published: January 2022

The objectives of this research were to develop control measures of postharvest diseases of citrus and deciduous fruits by using naturally-occurring, non-antibiotic-producing antagonists; study the mode of action of effective antagonists and optimize their application methods. Several antagonists were found against a variety of diseases of fruits and vegetables. One particularly effective yeast antagonist (US-7) was chosen for more in-depth studies. This antagonist outcompetes rot pathogens at the wound site for nutrients and space; it is better adapted than the pathogen to extreme environmental conditions such as temperature, humidity and osmotic changes, and is relatively resistant to common postharvest fungicides. Our data suggests that other modes of action may also be involved. These are induction of host resistance by the antagonists or its products, and direct interaction between the antagonists and the pathogen with the possible involvement of an extracellular material and/or cell wall degrading enzymes produced by the antagonist. However, these interactions were not fully elucidated. The antagonistic activity of US-7 and other biocontrol agents isolated, was enhanced by calcium salts. While the mode of action is not known, the addition of these salts had a significant effect both in laboratory experiments and in large-scale tests. Compatibility of the yeast antagonist with present packinghouse treatments and procedures was determined. An integrated control procedure was developed, utilizing the antagonists together with ultra-low dosages of fungicides and activity-enhancing additives. This cooperative research resulted in numerous publications describing the antagonistic agents. their mode of action and possible commercial application. Patents were developed from this research and a commercial company is pursuing the licensing of these patents and the testing of the procedure on a commercial scale. Our research findings have expanded the potential for using non-antibiotic-producing antagonistic microorganisms in the control of postharvest diseases of fruits and vegetables; thus meeting a critical need to find alternatives to the use of synthetic fungicides on food products.
Molecular Genetic Analysis of Pollination-Induced Senescence in Phalaenopsis Orchids
Authors: O'Neill Sharman , Halevy Abraham , Borochov Amihud
Published: January 2022

The project investigated the molecular genetic and biochemical basis of pollination-induced senescence of Phalaenopsis flowers. This experimental system offered unique advantages in that senescence is strictly regulated by pollination, providing the basis to experimentally initiate and synchronize senescence in populations of flowers. The postpollination syndrome in the Phalaenopsis orchid system was dissected by investigating the temporal and spatial regulation of ACC synthase gene expression. In the stigma, pollen-borne auxin induces the expression of the auxin-regulated ACC synthase (PS-ACS2) gene, resulting in ACC synthesis within 1 h following pollination. Newly formed ACC is oxidized by basal constitutive ACC oxidase to ethylene, which then induces the expression of the ethylene-regulated ACC synthase(PS-ACS1) and oxidase (ACO1) genes for further autocatalytic production of ethylene. It is speculated that during the 6-h period following pollination, emasculation leads to the production or release of a sensitivity factor that sensitizes the cells of the stigma to ethylene. ACC and ethylene molecules are translocated from the stigma to the labellum and perianth where ethylene induces the expression of PS-ACS1 and ACO1 resulting in an increased production of ACC and ethylene. Organ-localized ethylene is responsible for inrolling and senescence of the labellum and perianth. The regulation of ethylene sensitivity and signal transduction events in pollinated flowers was also investigated. The increase in ethylene sensitivity appeared in both the flower column and the perianth, and was detected as early as 4 h after pollination. The increase in ethylene sensitivity following pollination was not dependent on endogenous ethylene production. Application of linoleic and linoleic acids to Phalaenopsis and Dendrobium flowers enhanced their senescence and promoted ethylene production. Several major lipoxygenase pathway products including JA-ME, traumatic acid, trans-2-hexenal and cis-3-hexenol, also enhanced flower senescence. However, lipoxygenase appears to not be directly involved in the endogenous regulation of pollination-induced Phalaenopsis and Dendrobium flower senescence. The data suggest that short-chain saturated fatty acids may be the ethylene "sensitivity factors" produced following pollination, and that their mode of action involves a decrease in the order of specific regions i the membrane lipid bilayer, consequently altering ethylene action. Examination of potential signal transduction intermediates indicate a direct involvement of GTP-binding proteins, calcium ions and protein phosphorylation in the cellular signal transduction response to ethylene following pollination. Modulations of cytosolic calcium levels allowed us to modify the flowers responsiveness to ethylene.
Microbial Activity in the Rhizosphere in Relation to the Iron Nutrition of Plants
Authors: Chen Yona , Buyer Jeffrey , Hadar Yitzhak
Published: January 2022

Iron is the fourth most abundant element in the soil, but since it forms insoluble hydroxides at neutral and basic pH, it often falls short of meeting the basic requirements of plants and microorganisms. Most aerobic and facultative aerobic microorganisms possess a high-affinity Fe transport system in which siderophores are excreted and the consequent Fe complex is taken up via a cognate specific receptor and a transport pathway. The role of the siderophore in Fe uptake by plants and microorganisms was the focus of this study. In this research Rhizopus arrhizus was found to produce a novel siderophore named Rhizoferrin when grown under Fe deficiency. This compound was purified and its chemical structure was elucidated. Fe-Rhizoferrin was found to alleviate Fe deficiency when applied to several plants grown in nutrient solutions. It was concluded that Fe-Rhizoferrin is the most efficient Fe source for plants when compared with other among microbial siderophores known to date and its activity equals that of the most efficient synthetic commercial iron fertilizer-Fe EDDHA. Siderophores produced by several rhizosphere organisms including Rhizopus Pseudomonas were purified. Monoclonal antibodies were produced and used to develop a method for detection of the siderophores produced by plant-growth-promoting microorganisms in barley rhizosphere. The presence of an Fe-ferrichrome uptake in fluorescent Pseudomonas spp. was demonstrated, and its structural requirements were mapped in P. putida with the help of biomimetic ferrichrome analogs. Using competition experiments, it was shown that FOB, Cop B and FC share at least one common determinant in their uptake pathway. Since FC analogs did not affect FOB or Cop-mediated 55Fe uptake, it could be concluded that these siderophores make use of a different receptor(s) than FC. Therefore, recognition of Cop, FOB and FC proceeds through different receptors having different structural requirements. On the other hand, the phytosiderophores mugineic acid (MA and DMA), were utilized indirectly via ligand exchange by P. putida. Receptors from different biological systems seem to differ in their structural requirements for siderophore recognition and uptake. The design of genus- or species-specific drugs, probes or chemicals, along with an understanding of plant-microbe and microbe-microbe relationships as well as developing methods to detect siderophores using monoclonal antibodies are useful for manipulating the composition of the rhizosphere microbial population for better plant growth, Fe-nutrition and protection from diseases.
Coding, Expression, Targeting, Import and Processing of Distinct Polyphenoloxidases in Tissues of Higher Plants
Authors: Steffens John , Harel Eithan , Mayer Alfred
Published: January 2022

Polyphenol oxidase (PPO) catalyzes the oxidation of phenols to quinones at the expense of O2. PPOs are ubiquitous in higer plants, and their role in oxidative browning of plant tissues causes large annual losses to food production. Despite the importance of PPOs to agriculture, the function(s) of PPOs in higher plants are not understood. Among other roles, PPOs have been proposed to participate in aspects of chloroplast metabolism, based on their occurrence in plastids and high Km for O2. Due to the ability of PPO to catalyze formation of highly reactive quinones, PPOs have also been proposed to be involved in a wide array of defensive interactions with insect, bacterial, and fungal pests. Physiological and biochemical studies of PPO have provided few answers to the major problems of PPO function, subcellular localization, and biochemical properties. This proposal achieved the following major objectives: cloning of PPO cDNAs in potato and tomato; characterization of the tomato PPO gene family; antisense downregulation of the tomato PPO gene family; and reduction in post-harvest enzymic browning of potato through expression of antisense PPO genes under the control of tuber-specific promoters. In addition, we established the lumenal localization of PPO, characterized and clarified the means by which PPOs are imported and processed by chloroplasts, and provided insight into the factors which control localization of PPOs. This proposal has thereby provided fundamental advances in the understanding of this enzyme and the control of its expression.
Optimization of Diet for Post Larvel/Juvenile Sea Bass and Hybrid Stripped Bass Based on Enzymatic Profiles of their Digestive Tracts
Authors: Harpaz Sheenan , Hughes Steven G. , Lindner Pinhas
Published: January 2022

The overall goal of this research work was to identify the main proteolytic activities which take place in the digestive tracts of young bass fish, and use the knowledge acquired in order to improve feed protein utilization in juvenile fish based on their digestive capacity. The results of the work clearly showed that the young fish possess the entire profile of proteolytic enzymes which is found in adult fish. Yet, in the young fish the level of activity is substantially lower per gram tissue (or gram protein) as compared with the activity found in the digestive tracts of the same fish at an older (larger) age. In addition it was found that the main proteolytic enzyme in these fish is chymotrypsin which accounts for almost 80% of the proteolytic activity. An effort aimed at enhancing this activity has lead to the interesting finding that alcohol substantially enhances the proteolytic activity of fish intestines. Fish intestinal homogenates were used in order to evaluate the suitability of various feeds for the fish. Potential feed proteins were subjected to the proteolytic activity of the fish enzymes in vitro, in a manner simulating the natural process. The proteolytic activity was monitored by the valuation of the products, i.e. amino acid released. This method has proven to be a powerful tool which enables us to predict with a very high degree of accuracy the potential of a feed to promote growth. Selection of feed based on the proteolytic capacity of the fish degestive tracts can now be implemented in feed formulation, as anticipated in the original research proposal.
Molecular Karyotypes of Pathogeic Strains of Fusarium oxysporum
Authors: Kistler Harold Corby , Katan Talma , Zamir Dani
Published: January 2022

Genetic diversity of pathogenic strains of the fungus Fusarium oxysporum was determied by analysis of electrophoretic karyotype, as well as by DNA variation detected by Restriction Fragment Length Polymorphisms (RFLPs) and Random Amplified Polymorphic DNAs (RAPDs). The electrophoretic karyotypes for 130 isolates of the fungus pathogenic to tomato, melon, and banana were analyzed. Electrophoretic karyotype variation, reflected in differences in apparent chromosome number and genome size, was observed even among isolates from the same host and sub specific category. Sub specific categories studied were forma specialis, vegetative compatibility group (VCG) and race. Chromosome number and genome size variation was less for isolates within the same VCG than for the collection of isolates as a whole. RFLP and RAPD analysis were performed on 62 isolates of F. oxysporum from tomato and melon. Polygenetic trees were constructed from genetic diversity data. The results support the hypothesis that isolates belonging to the same VCG originate from a single ancestor compared to other isolates. The results do not support the hypothesis that all isolates belonging to the same forma specialis originate from a common ancestor. These conclusions have profound implication for breeding resistance to diseases caused by particular formae speciales of F. oxysporum.
Genetic Manipulation of the Adipose Tissue via Transgenesis
Authors: Shani Moshe , Emerson C.P.
Published: January 2022

The long term goal of this study was to reduce caloric and fat content of beef and other red meats by means of genetic modification of the animal such that fat would not be accumulated. This was attempted by introducing into the germ line myogenic regulatory genes that would convert fat tissue to skeletal muscle. We first determined the consequences of ectopic expression of the myogenic regulatory gene MyoD1. It was found that deregulation of MyoD1 did not result in ectopic skeletal muscle formation but rather led to embryonic lethalities, probably due to its role in the control of the cell cycle. This indicated that MyoD1 should be placed under stringent control to allow survival. Embryonic lethalities were also observed when the regulatory elements of the adipose-specific gene adipsin directed the expression of MyoD1 or myogenin cDNAs, suggesting that these sequences are probably not strong enough to confer tissue specificity. To determine the specificity of the control elements of another fat specific gene (adipocyte protein 2-aP2), we fused them to the bacterial b-galactosidase reporter gene and established stable transgenic strains. The expression of the reporter gene in none of the strains was adipose specific. Each strain displayed a unique pattern of expression in various cell lineages. Most exciting results were obtained in a transgenic strain in which cells migrating from the ventro-lateral edge of the dermomyotome of developing somites to populate the limb buds with myoblasts were specifically stained for lacZ. Since the control sequences of the adipsin or aP2 genes did not confer fat specificity in transgenic mice we have taken both molecular and genetic approaches as an initial effort to identify genes important in the conversion of a multipotential cell such as C3H10T1/2 cell to adipoblast. Several novel adipocyte cell lines have been established that differ in the expression of transcription factors of the C/EBP family known to be markers for adipocyte differentiation. These studies revealed that one of the genetic programming changes which occur during 10T1/2 conversion from multipotential cell to a committed adipoblast is the ability to linduce C/EBPa gene expression. It is expected that further analysis of this gene would identify elements which regulate this lineage-specific expression. Such elements might be good candidates in future attempts to convert adipoblasts to skeletal muscle cells in vivo.
Improving Greenhouse Microclimate Control with the Help of Plant Temperature Measurements
Authors: Fuchs Marcel , Segal Ishaiah , Dayan Ehude , Jordan K.
Published: January 2022

A model of the energy balance of a transpiring crop in a greenhouse was developed in a format suitable for use in climate control algorithms aimed at dissipating excess heat during the warm periods. The model's parameters use external climatic variables as input. It incorporates radiation and convective transfer functions related to the operation of control devices like shading screens, vents, fans and enhanced evaporative cooling devices. The model identified the leaf boundary-layer resistance and the leaf stomatal and cuticular resistance as critical parameters regulating the temperature of the foliage. Special experiments evaluated these variables and established their relation to environmental factors. The research established that for heat load conditions in Mediterranean and arid climates transpiring crops maintained their foliage temperature within the range allowing high productivity. Results specify that a water supply ensuring minimum leaf resistance to remain below 100 s m-1, and a ventilation rate of 30 air exchanges per hour, are the conditions needed to achieve self cooling. Two vegetable crops, tomato and sweet pepper fulfilled maintained their leaf resistance within the prescribed range at maturity, i.e., during the critical warm season. The research evaluates the effects of additional cooling obtained from wet pad systems and spray wetting of foliage.
Improvement of Prolificacy of Israeli and U.S. Sheep Breeds through Inclusion of the F Gene of the Booroola Merino-Stage II
Authors: Gootwine Elisha , Thomas David , Braw-Tal Ruth , Bor Amir , Dziuk P.J.
Published: January 2022

The purposes of this project were: 1) to introduce the FecB gene to the Awassi and Assaf breeds in Israel and the Rambouillet breed in the U.S.A. aiming in the long run to establish Awassi, Assaf and Rambouillet nucclei breeding flocks homozygous for the F gene in which the contribution of the Booroola Merino genetic background will be less than 10%; (In the U.S., Booroola crosses with Suffolk and Targhee were also studied. 2) to evaluate the effect of the FecB gene and different proportions of Booroola Merino genetic background on lamb survival, growth, milk production and wool production in Booroola crosses with the native breeds; 3) to reveal the specific effect of the FecB gene on ovarian development, follicle stimulating hormone (FSH) and inhibin secretion in prepubertal ewe lambs and in adult ewes in order to define physiological criteria for distinguishing carriers of the FecB allele from non-carriers and 4) to identify genetic markers linked to the FecB gene to assist in selection of genotypes within the Booroola crosses. Introgression of the Booroola gene reached the stage of the third backcross in the Awassi, Assaf and the Rambouillet crosses. In all cases the Booroola crosses were superior in prolificacy. However, they were inferior in comparison to the local breeds in production due to Booroola Merino genes other than the FecB. It is expected that the beneficial economic contribution of the Booroola gene will increase along with the upgrading to the local breeds. FSH plasma levels and induced ovulation rate of 5 month old FecB carriers among the crossbreeds. The OarAE101 marker can assist in detecting FecB carriers among Booroola-Awassi crosses. However, this marker is informative only in some of the families.
Traction-Soil Compaction Tradeoffs as a Function of Dynamic Soil-Tire Interation Due to Varying Soil and Loading Conditions
Authors: Upadhyaya Shrini , Wolf Dan , Chancellor William J. , Shmulevich Itzhak , Hadas Amos
Published: January 2022

The objectives of this study were to investigate soil-pneumatic tire interaction and develop traction-soil compaction prediction model. We have developed an inverse solution technique that employs a response surface methodology to determine engineering properties of soil in-situ. This technique is useful in obtaining actual properties of soil in-situ for use in traction and soil compaction studies rather than using the values obtained in the laboratory by employing remolded and/or disturbed soil samples. We have conducted extensive field tests i the U.S. to develop semi-empirical traction prediction equation for radial ply tires. A user friendly traction-soil compaction program was developed to predict tractive ability of radial ply tires using several different techniques and to estimate soil compaction induced by these tires. A traction prediction model that incorporates strain rate effects on the tractive ability of tires was developed in Israel. A mobile single wheel tester and an in-situ soil test device were developed i Israel to significantly enhance the ability of Israeli investigators to conduct traction-soil compaction research. This project has resulted in close cooperation between UCD, Technion, and ARO, which will be instrumental in future collaboration.
Protection of Cattle Against Babesiosis: Immunization with Recombinant DNA Derived Apical Complex Antigens of Babesia bovis
Authors: McElwain Terry , Pipano Eugene , Palmer Guy , Shkap Varda , Hines Stephen , Jasmer Douglas
Published: January 2022

Bovine babesiosis caused by Babesia bovis continues to be a significant deterrent to global livestock production. Current control methods have both biological and technical drawbacks that have stimulated research on improved methods of vaccination. This BARD project has focused on characterization of candidate Babesia bovis vaccine antigens located in the apical complex, a unique group of subcellular organelles - including rhoptries, micronemes, and spherical bodies - involved in the invation of erythrocytes. Spherical bodies and rhoptries were partially purified and their contents characterized using monoclonal antibodies. Existing and newly developed monoclonal antibodies bound to antigens in the spherical body, rhoptry, merozoite membrane, and infected erythrocyte membrane. In an initial immunization study using biologically cloned strains, it was demonstrated that strain-common epitopes are important for inducing immune protection against heterologous challenge. Rhoptry-associated antigen 1 (RAP-1) had been demonstrated previously to induce partial immune protection, fulfilled criteria of broad interstrain B and T cell epitope conservation, and thus was further characterized. The RAP-1 gene family consists of at least two gene copies, is homologous to the RAP-1 gene family in B. bigemina, and contains significant sequence similarity to other erythroparasitic protozoan candidate vaccine antigens, including the apical membrane antigen of Plasmodium falciparum. A new RAP-1 monoclonal antibody was developed that inhibits merozoite growth in vitro, demonstrating the presence of a RAP-1 neutralization sensitive domain. Based on these observations, cattle were immunized with Mo7 (Mexico) strain recombinant RAP-1 representing one of the two gene copies. All cattle responded with variable levels of serum antibodies inhibitory to heterologous Israel strain merozoite growth in vitro, and RAP-1 specific T lymphocytes that proliferated when stimulated with either homologous or heterologous native parasite antigen. Minimal protection from clinical disease was present after virulent Israel (heterologous) strain B. bovis challenge. In total, the results support the continued development of RAP-1 as a vaccine antigen, but indicate that additional information about the native structure and function of both RAP-1 gene copies, including the relationship of conserved and polymorphic sequences to B and T cell lepitopes relevant for protection, is necessary for optimization of RAP-1 as a vaccine component.
Physiological and Molecular Characterization of the Response to Ethylene during Senescence of Carnation Genotypic Variants
Authors: Woodson William , Mayak Shimon , Rabinowitch Haim
Published: January 2022

The senescence of carnation (Dianthus caryophyllus L.) flowers is associated with increased production of the phytohormone ethylene, which in turn serves to initiate and regulate the processes involved in programmed petal death. We investigated the regulation of ethylene production and petal senescence in carnation. Several carnation genotypes were identified that exhibited extended vase-life in comparison to flowers from typical commercial cultivars. The capacity of these genotypes to produce ethylene during postharvest vase-life and to respond to exogenous ethylene was investigated. Several genotypes, represented by 'Sandrosa' and 87-37G produced little ethylene durig their postharvest vase-life and as a result failed to exhibit the symptoms (in-rolling and wilting) typical of flowers producing elevated levels of ethylene. These genotypes were further separated by their capacity to respond to exogenous ethylene by both increased ethylene synthesis and premature petal senescence. In one case a genotype (799) was identified that was not capable of responding to exogenous ethylene by either increased ethylene production or premature petal senescence. The regulation of ethylene production during petal senescence was investigated both at the enzyme and gene levels. A full length cDNA was identified for the petal senescence-related ACC synthase gene. Utilizing this, and other ethylene biosynthetic pathway cDNA probes, an increase in both ACC synthase and ACC oxidase mRNAs were detected following ethylene treatment. An increase in ACC oxidase mRNA and enzyme activity was detected within 2-3 h following ethylene treatment, indicating the expression of this gene is an early response to ethylene. An investigation into the expression of novel proteins during petal senescence revealed a number of polypeptides increased in abundance and possibly play a role in the regulation or biochemical processes of senescence. One polypeptide of 70 kDa was identified as being encoded by the previously characterized gene SR12 and possibly represents a b-galactosidase involved in the remobilization of carbohydrates during senescence.
Using Flavonoids to Control in vitro Development of Vesicular Arbuscular Mycorrhizal Fungi
Authors: Phillips Donald , Kapulnik Yoram
Published: January 2022

Vesicular-arbuscular mycorrhizal (VAM) fungi and other beneficial rhizosphere microorganisms, such as Rhizobium bacteria, must locate and infect a host plant before either symbiont profits. Although benefits of the VAM association for increased phosphorous uptake have been widely documented, attempts to improve the fungus and to produce agronomically useful amounts of inoculum have failed due to a lack of in vitro production methods. This project was designed to extend our prior observation that the alfalfa flavonoid quercetin promoted spore germination and hyphal growth of VAM fungi in the absence of a host plant. On the Israeli side of the project, a detailed examination of changes in flavonoids and flavonoid-biosynthetic enzymes during the early stages of VAM development in alfalfa found that VAM fungi elicited and then suppressed transcription of a plant gene coding for chalcone isomerase, which normally is associated with pathogenic infections. US workers collaborated in the identification of flavonoid compounds that appeared during VAM development. On the US side, an in vitro system for testing the effects of plant compounds on fungal spore germination and hyphal growth was developed for use, and intensive analyses of natural products released from alfalfa seedlings grown in the presence and absence of microorganisms were conducted. Two betaines, trigonelline and stachydrine, were identified as being released from alfalfa seeds in much higher concentrations than flavonoids, and these compounds functioned as transcriptional signals to another alfalfa microsymbiont, Rhizobium meliloti. However, these betaines had no effect on VAM spore germination or hyphal growth i vitro. Experiments showed that symbiotic bacteria elicited exudation of the isoflavonoids medicarpin and coumestrol from legume roots, but neither compound promoted growth or germination of VAM fungi in vitro. Attempts to look directly in alfalfa rhizosphere soil for microbiologically active plant products measured a gradient of nod-gene-inducing activity in R. meliloti, but no novel compounds were identified for testing in the VAM fungal system in vitro. Israeli field experiments on agricultural applications of VAM were very successful and developed methods for using VAM to overcome stunting in peanuts and garlic grown in Israel. In addition, deleterious effects of soil solarization on growth of onion, carrot and wheat were linked to effects on VAM fungi. A collaborative combination of basic and applied approaches toward enhancing the agronomic benefits of VAM asociations produced new knowledge on symbiotic biology and successful methods for using VAM inocula under field conditions
Spiroplasmas as Biological Control Agents of Insect Pests
Authors: Hackett Kevin , Rottem Shlomo , Williamson David L. , Klein Meir
Published: January 2022

Toward development of spiroplasmas as novel toxin-delivery systems for biocontrol of beetle pests in the United States (Leptinotarsa decemlineata) and Israel (Maladera matrida), media for cultivating beetle-associated spiroplasmas were improved and surveys of these spiroplasmas were conducted to provide transformable strains. Extensive surveys of spiroplasmas yielded promising extrachromosomal elements for vector constructs. One, plasmid pCT-1, was cloned, characterized, and used as a source of spiroplasma origin of replication in our shuttle vectors. The fibrillin gene was isolated and sequenced and its strong promoter was also used in the constructs. Means for transforming these vectors into spiroplasmas were developed and optimized, with electroporation found to be suitable for most applications. Development and optimization of means for using large unilamellar vesicles (LUVs) in spiroplasma transformation represents a breakthrough that should facilitate insertion of large clusters of virulence genes. With completion of the vector, we should thus be poised to genetically engineer spiroplasmas with genes that will express toxins lethal to our target beetles, thus providing an effective and inexpensive alternative to conventional means of beetle control.
Virus Encoded Toxin of the Corn Smut Ustilago Maydis - Isolation of Receptors and Mapping Functional Domains
Authors: Mevarech Moshe , Bruenn Jeremy , Koltin Yigal
Published: January 2022

Ustilago maydis is a fungal pathogen of maize. Some strains of U. maydis encode secreted polypeptide toxins capable of killing other susceptible strains of U. maydis. Resistance to the toxins is conferred by recessive nuclear genes. The toxins are encoded by genomic segments of resident double-strande RNA viruses. The best characterized toxin, KP6, is composed of two polypeptides, a and b, which are not covalently linked. It is encoded by P6M2 dsRNA, which has been cloned, sequenced and expressed in a variety of systems. In this study we have shown that the toxin acts on the membranes of sensitive cells and that both polypeptides are required for toxin activity. The toxin has been shown to function by creating new pores in the cell membrane and disrupting ion fluxes. The experiments performed on artificial phospholipid bilayers indicated that KP6 forms large voltage-independent, cation-selective channels. Experiments leading to the resolution of structure-function relationship of the toxin by in vitro analysis have been initiated. During the course of this research the collaboration also yielded X-ray diffracion data of the crystallized a polypeptide. The effect of the toxin on the pathogen has been shown to be receptor-mediated. A potential receptor protein, identified in membrane fractions of sensitive cells, was subjected to tryptic hydrolysis followed by amino-acid analysis. The peptides obtained were used to isolate a cDNA fragment by reverse PCR, which showed 30% sequence homology to the human HLA protein. Analysis of other toxins secreted by U. maydis, KP1 and KP4, have demonstrated that, unlike KP6, they are composed of a single polypeptide. Finally, KP6 has been expressed in transgenic tobacco plants, indicating that accurate processing by Kex2p-like activity occurs in plants as well. Using tobacco as a model system, we determined that active antifungal toxins can be synthesized and targeted to the outside of transgenic plant cells. If this methodology can be applied to other agronomically crop species, then U. maydis toxins may provide a novel means for biological control of pathogenic fungi.
Design and Function of Modified Atmosphere Packaging Systems for Fresh Produce: a Unified Approach for Optimizing Oxygen, Carbon Dioxide and Relative Humidity
Authors: Cameron Arthur , Ben-Yehoshua Shimshon , Hernandez Rebecca
Published: January 2022

Oxygen uptake, CO2 production and respiratory quotient (RQ) of strawberry, raspberry and cherry were measured as functions of temperature and oxygen level. The effect of cultivar was studied in strawberry ('Honey' and 'Allstar'). The effect of harvest date was studied for raspberry. The lower O2 limit increased markedly with incraqsing temperature for all fruits studied. Red bell pepper O2 uptake was measured as a function of O2 at 20o C. Lowering the inpackage humidity using NaCl reduced decay of bell pepper sealed in low-density polyethylene packages when stored at 8o C. Analyses of a model developed for MA-packaged red bell pepper fruit demonstrated that when RQ was near one and when CO2 exceeded O2 permeability, transient CO2 levels increased to a maximum before dropping to steady-state levels. An isothermal model of O2, CO2 and water vapor exchange in MA packages was developed for red bell pepper and tested empirically. A comprehensive model was developed for small fruits that also incorporated water vapor and the effects of changing temperature. Variation in package O2 levels was measured and modeled as a function of variation in respiration and film permeability.
Mechanisms of Oxidant Resistance in Weed and Crop Species
Authors: Grene Alscher Ruth , Gressel Jonathan , Cramer Carole , Warshawsky Abraham , Grabau Elizabeth
Published: January 2022

A large body of evidence has accumulated showing that plant strains that are tolerant to a particular oxidant stress have a modicum of cross-tolerance to other oxidant stresses, whether caused by transient heat, drought, cold or oxidizing air pollutants or herbicides. We have studied a multienzyme scavenging system associated with oxidant tolerance at the metabolic and molecular levels in the model systems of pea and Conyza. Data from our experimental systems suggest that both development and subcellular compartmentalization play important roles in stress tolerance. The behavior of the chloroplast may differ from that of the cytosol. Further study of these controls is needed to acquire the understanding needed to generate oxidant stress tolerant field crops.
Optimal Environmental Control for Indeterminate Greenhouse Crops
Authors: Seginer Ido , Jones James , Gutman Per-Olof , Vallejos Eduardo
Published: January 2022

Increased world competition, as well as increased concern for the environment, drive all manufacturing systems, including greenhouses, towards high-precision operation. Optimal control is an important tool to achieve this goal, since it finds the best compromise between conflicting demands, such as higher profits and environmental concerns. The report, which is a collection of papers, each with its own abstract, outlines an approach for optimal, model-based control of the greenhouse environment. A reliable crop model is essential for this approach and a significant portion of the effort went in this direction, resulting in a radically new version of the tomato model TOMGRO, which can be used as a prototype model for other greenhouse crops. Truly optimal control of a very complex system requires prohibitively large computer resources. Two routes to model simplification have, therefore, been tried: Model reduction (to fewer state variables) and simplified decision making. Crop model reduction from nearly 70 state variables to about 5, was accomplished by either selecting a subset of the original variables or by forming combinations of them. Model dynamics were then fitted either with mechanistic relationships or with neural networks. To simplify the decision making process, the number of costate variables (control policy parametrs) was recuced to one or two. The dry-matter state variable was transformed in such a way that its costate became essentially constant throughout the season. A quasi-steady-state control algorithm was implemented in an experimental greenhouse. A constant value for the dry-matter costate was able to control simultaneously ventilation and CO2 enrichment by continuously producing weather-dependent optimal setpoints and then maintaining them closely.
Electrostatic Processes Underlying Natural and Mechanized Transfer of Pollen
Authors: Law Edward , Gan-Mor Samuel , Wetzstein Hazel , Eisikowitch Dan
Published: January 2022

The project objective was to more fully understand how the motion of pollen grains may be controlled by electrostatic forces, and to develop a reliable mechanized pollination system based upon sound electrostatic and aerodynamic principles. Theoretical and experimental analyses and computer simulation methods which investigated electrostatic aspects of natural pollen transfer by insects found that: a) actively flying honeybees accumulate ~ 23 pC average charge (93 pC max.) which elevates their bodies to ~ 47 V likely by triboelectrification, inducing ~ 10 fC of opposite charge onto nearby pollen grains, and overcoming their typically 0.3-3.9 nN detachment force resulting in non-contact electrostatic pollen transfer across a 5 mm or greater air gap from anther-to-bee, thus providing a theoretical basis for earlier experimental observations and "buzz pollination" events; b) charge-relaxation characteristics measured for flower structural components (viz., 3 ns and 25 ns time constants, respectively, for the stigma-style vs. waxy petal surfaces) ensure them to be electrically appropriate targets for electrodeposition of charged pollen grains but not differing sufficiently to facilitate electrodynamic focusing onto the stigma; c) conventional electrostatic focusing beneficially concentrates pollen-deposition electric fields onto the pistill tip by 3-fold as compared to that onto underlying flower structures; and d) pollen viability is adequately maintained following exposure to particulate charging/management fields exceeding 2 MV/m. Laboratory- and field-scale processes/prototype machines for electrostatic application of pollen were successfully developed to dispense pollen in both a dry-powder phase and in a liquid-carried phase utilizing corona, triboelectric, and induction particulate-charging methods; pollen-charge levels attained (~ 1-10 mC/kg) provide pollen-deposition forces 10-, 77-, and 100-fold greater than gravity, respectively, for such charged pollen grains subjected to a 1 kV/cm electric field. Lab and field evaluations have documented charged vs. ukncharged pollen deposition to be significantly (a = 0.01-0.05) increased by 3.9-5.6 times. Orchard trials showed initial fruit set on branches individually treated with electrostatically applied pollen to typically increase up to ~ 2-fold vs. uncharged pollen applications; however, whole-tree applications have not significantly shown similar levels of benefit and corrective measures continue. Project results thus contribute important basic knowledge and applied electrostatics technology which will provide agriculture with alternative/supplemental mechanized pollination systems as tranditional pollen-transfer vectors are further endangered by natural and man-fade factors.