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Genetic and molecular studies on the accumulation of bioactive compounds in Cannabis sativa L.
Full text linkCannabis is a predominantly dioecious and phenotypically diverse, monotypic genus consisting of
a single species, the Cannabis sativa. Its cultivation started in Eurasia, several thousand years ago, where the
selective pressure that has led it to be cultivated around the globe today began. As a dioecious plant, C. sativa
is an obligate outbreeder, and as such every individual plant is genetically unique, and producing offspring
with desired traits can be challenging. This genetic variation can be both a blessing and a curse for breeders,
because it provides a rich genetic pool from which to select for desired traits, but also it can be difficult to
achieve consistency and stability in breeding programs. The current C. sativa constraints, such as its high level
of heterozygosity, reside in the limited genetic improvement and poor conservation of genetic resources,
resulting from prohibition against the plant as a source of one of the most widespread illicit drugs. Unlike
major crops, C. sativa has suffered from a lack of progress in the knowledge of its physiology and has not
benefit from advances in breeding technologies. In recent years, there has been growing interest in the
potential of C. sativa for both medicinal and industrial purposes. Its legalization in many countries has led to
increased research and investment in the cultivation, processing, and marketing of hemp and medical
Cannabis products. As a result, the plant is gaining recognition as a valuable crop with significant economic,
environmental, and health benefits. The plasticity and wide genetic variability represent the intrinsic
functionality of this plant and emphasise the agricultural value of the species. The long stem fibres have been
used for millennia as the predominant source of fibre in the textile and paper industry. The seeds are suitable
for human and animal consumption and contain a balanced ratio of omega-6/omega-3 essential
polyunsaturated fatty acids. In addition to traditional uses, one of the main applications today is Cannabis as
a source of countless bioactive compounds. Indeed, C. sativa female flowers are rich in bioactive compounds
belonging to the secondary metabolism with remarkable phytochemical potential. These compounds are
mostly classified into three classes: phytocannabinoids, terpenoids and phenolics. Phytocannabinoids are the
most studied compounds, mainly due to their wide range of pharmaceutical effects in humans, with more
than 150 constituents identified, of which THCA, CBDA, CBGA and CBCA are the most representative. Over
the last five years, significant advances in C. sativa genetic research have led to a deeper understanding of
the plant's genetic background and its potential applications. With the increasing legalization and
commercialization, genetic research has become a critical tool for developing new strains with desired traits
and improving the quality and consistency of C. sativa products. One major breakthrough in C. sativa genetic
research has been the sequencing of the genome, providing valuable insights into the plant's complex
genetics and the biochemical pathways that produce its various phytocannabinoids and terpenes. Other
recent studies have focused on identifying the genetic markers associated with specific traits, such as high
THCA or CBDA content, flowering time, disease resistance, and yield. Advances in new breeding techniques,
such as CRISPR-Cas9, have also opened up new possibilities for editing genome for a desired trait. In addition,
genetic research has also shed light on the evolutionary history of the plant and its relationship with other
members of the Cannabaceae family, helping to clarify the taxonomic classification of different genotypes.
Overall, the recent years have seen significant progress in C. sativa genetic research, providing new insights
into the plant's biology and potential applications for human health and industry. There is also a growing
interest in the study of the plant's genetics and molecular biology. By identifying the genes and pathways
involved in phytocannabinoids biosynthesis, as well as the regulatory mechanisms that control their
expression, new strategies can be developed for manipulating their production, with important applications
in medicine, industry, and agriculture. In this Doctoral Thesis, C. sativa genetic was studied with the aim of
better understanding the route leading to phytocannabinoids synthesis. Both industrial and medicinal
varieties were used, tapping into the biodiversity available within a germplasm collection maintained at CREA-
Research Centre for Cereal and Industrial Crops in Bologna and Rovigo sites, where it was also possible to
cultivate high-THC strains in outdoor and indoor facilities authorized with decree n. SP/041 on 13rd March
2017 according to art. 26 of the D.P.R. 309/90). In the first chapter an investigation of the genetic and
transcriptional variability of cannabinoid synthases is illustrated, performed on a set of Italian and French C.
sativa genotypes with diverse chemotypes. The work focused also on the role of the cannabichromenic acid
synthase (CBCAS), for a long time neglected, and considered a gene peculiar to fibre genotypes, considered
a mutated, non-functional copy of THCAS for their extremely high sequence similarity. The results showed
that CBCAS is present and expressed in both drug-type and fiber-type genotypes, and several genetic variants
of CBCAS genes were identified, which may contribute to differences in phytocannabinoid production
between different chemotypes. In the second chapter the transcription analyses of cannabinoid pathway
genes, during early vegetative stages of plant development are reported. Besides cannabinoid synthases, also
other genes responsible for early reaction in the synthesis of these terpeno-phenolic compounds were
analysed in order to deepen knowledge for defining the main determinants of this metabolism in the early
stages of plant life. Cannabicromenic acid was found the first cannabinoid accumulated in the seedlings,
shortly after emergence, and hypotheses are given on the regulation of its synthesis in planta. Moreover, in
this chapter is also reported the transcription of cannabinoid synthase genes during seed germination and in
long-storage seeds, uncovering a new and important level of gene regulation during seed germination and
providing an estimate of the importance of this metabolism for the plant. The third chapter focused on the
analysis of a cultivated population of the FINOLA variety, obtained from the certified commercial seed. As
with many industrial varieties, FINOLA has a chemotype III and derives from years of breeding, however it still
accumulates little amount of THC (residual THC) on inflorescence which can exceed the legal limit and cause
seizure and losses to growers. The results show how the B1080/B1192 molecular marker was effective at
identifying hemp plants with functional THCA synthase and total THC content above the legal limit.
Biochemical analyses also demonstrated a 100% association between the chemotype predicted by molecular
markers and the actual chemotype. This study suggests that molecular markers could be used as effective
tools for hemp growers and breeders, helping to ensure compliance with regulations and avoid legal issues
related to hemp cultivation. The possibility of combining the micropropagation with the maintenance and
renewal of mother plants, deputed to the national production of medical cannabis was evaluated and
reported in chapter four. Overall, the work provided a valuable protocol for the micropropagation of C. sativa
involving the use of cytokinin and gibberellin-based media for the induction and proliferation of shoots,
followed by rooting on a separate rooting medium. The results also demonstrated the successful
acclimatization and transfer of in vitro-derived plants to ex-vitro conditions and the potential for using
micropropagation as a tool for the genetic improvement and development of new C. sativa plants but also
for the preservation of genetic diversity
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Insights into terpenes profiling and transcriptional analyses during flowering of different Cannabis sativa L. chemotypes
No full textTerpenes, volatile compounds known for their aromatic and therapeutic properties, play a pivotal role in shaping the overall chemical profile of Cannabis sativa L. Their biosynthesis in planta occurs in trichomes and involves the 2-C-methyl-D-erythritol 4-phosphate (MEP) and the mevalonic acid (MVA) pathways, responsible for producing the substrates utilized by a family of enzymes, the terpene synthases (TPS), for terpene production. In this work, a comprehensive approach combining chemical analyses of the volatile compounds characterizing the aroma of the inflorescences three C. sativa genotypes collected at three stages of maturity and the transcriptional analyses of key genes involved in the terpene biosynthesis was adopted to study this pathway. The results revealed different terpene profiles among genotypes, which were characterized by peculiar compounds belonging to the sesqui- (CINBOL and Fibrante) or monoterpene (Ermo) categories. Both structural and putative regulatory genes were analysed by RT-qPCR, revealing distinct transcriptional profiles of Terpene Synthases, contributing to the diversity of mono and sesquiterpenes synthesized. Furthermore, the research delved into potential regulatory genes associated with trichome formation, a crucial factor influencing terpene accumulation. This integrated approach highlighted complex mechanisms governing terpene accumulation in cannabis, while also offering potential regulators putatively involved in this pathway
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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