196,051 research outputs found
Concise synthesis of vinylheterocycles through beta-elimination under solventless phase transfer catalysis conditions
No full textVarious vinylheterocycles compounds have been prepared in excellent yields through betaelimination of the corresponding sulfonate esters with 50% aq NaOH under phase transfer catalysis conditions without organic solvent. The new approach provides an economic and environmentally friendly solution to removal of hazardous bases as well as toxic and expensive dipolar aprotic solvents
Study of Pollen Traits, Production, and Artificial Pollination Methods in <i>Zea mays</i> L.
No full textThe optimization of artificial pollination is crucial in breeding programs for allogamous plants. In maize, achieving a balance between the labor-intensive nature of controlled pollinations and the need for large-scale production of hybrid seeds, along with considerations of germinability and pollen production, determines the success of genetic improvement programs. Breeding programs in maize have resulted in a reduction in the number of tassel branches to increase light interception and plant density in production fields. However, despite this genetic improvement, the decreased pollen production per plant has raised critical concerns regarding pollination and subsequent ear filling, especially under adverse environmental conditions. The aim of this work was the analysis of factors that can contribute to increasing the efficiency of controlled pollination in maize. The data obtained showed that pollen diameter, flavonoid, and phenolic acid content do not influence the percentage of germination and therefore the efficiency of pollination. The quantity of pollen is a central factor in ensuring the efficiency of controlled pollinations, and the data obtained by comparing traditional varieties with modern hybrids of maize showed that an increase in pollen production is determined by the increase in branching of the male inflorescence. Furthermore, we propose the use of a “smart” pollination method to make this step in maize breeding programs easier and faster
GENETIC IMPROVEMENT OF CAMELINA SATIVA: DEVELOPMENT OF NEW VARIETIES AND EXPLORATION OF ITS POTENTIAL AS AN INTERMEDIATE CROP
No full textIn recent years, Camelina sativa has gained considerable attention as a sustainable crop, known for its resilience under harsh conditions and low input requirements. It is being explored for its potential as a biofuel source and for the production of omega-3 rich oil. Furthermore, its role in improving soil health through crop rotation and its environmental benefits, such as reducing greenhouse gas emissions, have further increased its attractiveness. This doctoral thesis presents an overview of research on the allelopathic and agronomic benefits of Camelina, in particular its potential in integrated management. The thesis examines progress in camelina breeding through traditional methods, biotechnological approaches, evaluating its potential to improve the crop (improvements in yield, oil content and reduction of anti-nutritional compounds such as glucosinolates). He underlines the importance of genetic diversity and proposes two selection strategies: one that involves crossing spring varieties and the other that crosses spring and winter varieties. Breeding programs have shown that winter cultivation in Northern Italy led to significantly higher yields than spring cultivation. Furthermore, a synthetic population of Camelina sativa was identified as adaptable with a low glucosinolate content, making it resilient to different environments. Molecular analysis made it possible to identify genetic differences between winter and spring varieties. Finally, the promising new variety (C1244) shows early maturity, high seed weight and oil content, offering potential for use in several sectors
The role of husk traits in maize susceptibility to Fusarium verticillioides: A multi-location study in northern Italy
No full textFusarium disease and the consequent mycotoxin accumulation pose significant problem in maize cultivation, with fumonisins produced by Fusarium verticillioides posing a global health concern. To address this issue, a range of preventive measures (e.g. crop management techniques) can be implemented to minimize fungal infections. A promising strategy to counteract this issue involves the selection of genotypes with greater resistance to fungal pathogens. This approach has the potential to reduce the reliance on chemical inputs for controlling fungus growth or indirect infection vectors. Leveraging genetic approaches can help improve the economic sustainability of agriculture in the face of climate change challenges. In the present work, we assessed the importance of two husk leaf traits (coverage and number), their association with F. verticillioides infection, fumonisin content, and their potential influence on crop yield. The study was conducted in three locations in the North of Italy and 38 hybrids with varying resistance to F. Verticillioides were compared. The results obtained showed that husk coverage has a pivotal role not only in protecting maize ears from Fusarium infection but have also a significant impact on crop yield: a significant positive correlation was found between husk coverage and yield in all three locations (r = 0.33185; r = 0.51327 and r = 0.51207, respectively). Furthermore, in the field of Vicenza, a significant negative correlation was found between husk coverage and Fusarium severity (r = -0.41492). Husk coverage emerges as an important trait that merits inclusion in maize breeding programs, given its protective role against fungal infections and its favourable influence on both yield and grain quality
Opportunities and Challenges of Castor Bean (Ricinus communis L.) Genetic Improvement
No full textCastor bean (Ricinus communis L.) originated in East Africa and then diffused to warm-temperate, subtropical, and tropical regions of the world. The high lipid content in the castor beans is extracted for use in pharmaceutical and industrial applications. The castor oil lipid profile is naturally composed of 90% ricinoleic acid and the remaining 10% is mainly composed of linoleic, oleic, stearic, and linolenic fatty acids. The highly toxic compound ricin within the seeds is insoluble in oil, making castor oil free from this toxin and safe to use for industrial and cosmetic applications. Among the main uses of castor oil are reported industrial uses such as component for lubricants, paints, coatings, polymers, emulsifiers, cosmetics, and medicinal uses as a laxative. There is also significant commercial potential for utilization of the whole castor bean plant such as animal feed, fertilizer, biofuel, and also for phytoremediation. Several breeding programs have been planned to improve the castor’s characteristics needed for its current or potential uses. In this review, after summarizing data on castor bean agronomy and uses, we focus on the main advances in Castor bean classical and biotechnological breeding programs, underlining the high potential of this oil crop. In particular, the main challenges of castor breeding programs are to increase yield, mainly through the selection of growth habits allowing mechanized harvest, and beneficial compound content, mainly the oil, and to decrease the toxic compounds content, mainly ricin
Fragmenta picta. Affreschi e mosaici staccati del Medioevo romano, catalogo della mostra, Museo Nazionale di Castel Sant’Angelo, Roma 15 dicembre 1989-18 febbraio 1990
No full textCompression strategies and space-conscious representations for deep neural networks
No full textRecent advances in deep learning have made available large, powerful convolutional neural networks (CNN) with state-of-the-art performance in several real-world applications. Unfortunately, these large-sized models have millions of parameters, thus they are not deployable on resource-limited platforms (e.g., where RAM is limited). Compression of CNNs becomes therefore a critical problem to achieve memory-efficient and possibly computationally faster model representations. In this paper, we investigate the impact of lossy compression of CNNs by weight pruning and quantization, and lossless weight matrix representations based on source coding. We tested several combinations of these techniques on four benchmark datasets for classification and regression problems, achieving compression rates up to 165 times, while preserving or improving the model performance
Reproducing the Sparse Huffman Address Map Compression for Deep Neural Networks
No full textDeploying large convolutional neural networks (CNNs) on limited-resource devices is still an open challenge in the big data era. To deal with this challenge, a synergistic composition of network compression algorithms and compact storage of the compressed network has been recently presented, substantially preserving model accuracy. The proposed implementation, which we describe in this paper, offers different compression schemes (pruning, two types of weight quantization, and their combinations) and two compact representations: the Huffman Address Map compression (HAM), and its sparse version sHAM. Taken as input a model, trained for a given classification or regression problem (as well as the dataset employed, which is necessary for the fine-tuning of weights after network compression), the procedure returns the corresponding compressed model. Our publicly available implementation provides the source code, two pre-trained CNN models (retrieved from third-party repositories referring to well-established literature), and four datasets. This implementation includes detailed instructions to execute the scripts and reproduce the obtained results, in terms of the figures and tables included in the original paper
Genetic Improvement of Camelina sativa (L.) Crantz: Opportunities and Challenges
No full textIn recent years, a renewed interest in novel crops has been developing due to the environmental issues associated with the sustainability of agricultural practices. In particular, a cover crop, Camelina sativa (L.) Crantz, belonging to the Brassicaceae family, is attracting the scientific community’s interest for several desirable features. It is related to the model species Arabidopsis thaliana, and its oil extracted from the seeds can be used either for food and feed, or for industrial uses such as biofuel production. From an agronomic point of view, it can grow in marginal lands with little or no inputs, and is practically resistant to the most important pathogens of Brassicaceae. Although cultivated in the past, particularly in northern Europe and Italy, in the last century, it was abandoned. For this reason, little breeding work has been conducted to improve this plant, also because of the low genetic variability present in this hexaploid species. In this review, we summarize the main works on this crop, focused on genetic improvement with three main objectives: yield, seed oil content and quality, and reduction in glucosinolates content in the seed, which are the main anti-nutritional substances present in camelina. We also report the latest advances in utilising classical plant breeding, transgenic approaches, and CRISPR-Cas9 genome-editing
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