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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Application of dietary b-1,3-glucan in enhancing resistance of Penaeus monodon against vibrio and viral infections

Chang, Cheng-Fang 17 July 2000 (has links)
Three series of studies were conducted to quantify the effectiveness of dietary incorporation of b-1,3-glucan (BG) from Schizophyllum commune in enhancing the immunity and resistance of grass prawn Penaeus monodon to vibriosis and white spot syndrome virus (WSSV) infections. In the first series of studies, three experiments were conducted to evaluate the effectiveness of dietary b-1,3-glucan on shrimp growth and resistance to vibriosis. Weight gain, survival and feed efficiency of juvenile shrimp (0.5 ¡Ó 0.1 g) were not significantly different (P>0.05) after being fed the diets containing BG 0, 0.2, 2, 10 g/kg diet for 18 weeks. Subadult shrimp (20.4 ¡Ó 2.1 g) fed the diet containing of BG 2 g/kg diet for 10 days showed a significantly (P<0.001) enhanced resistance against vibriosis. Postlarvae fed with the BG diet (2 g/kg diet) were more resistant (P<0.001) against starvation and V. harveyi challenges than the postlarvae fed non-BG diet. Additive disease resistance was observed when polyphosphorylated L-ascorbic acid (PAA) was used together with BG. In challenge tests with V. damsela, shrimp fed with PAA (0.2 g/kg diet) + BG (2 g/kg diet) diet for 20 days had a survival rate up to 60%. In the second series of studies, two experiments were conducted to evaluate the effectiveness of dietary b-1,3-glucan on wound healing and immunity in spawners. Dietary supplement of BG reduced the chance of infections, but did not help wound healing as did the supplement of PAA. And regardless of indoor or outdoor rearing, the survival rate of brooder (135 ¡Ó 25 g) fed the BG (2 g/kg diet) diet was higher (P<0.001) than that of the non-BG group. Fed the BG brooders showed enhanced haemocyte phagocytic activity, cell adhesion and superoxide anion production then the control group. Third series of studies evaluated the effectiveness against white spot syndrome virus (WSSV). Six days after being challenged with WSSV, 12.2 % of the BG-treated (2 g/kg diet for 15 days) postlarvae (PL15) and 20 % BG-treated (2 g/kg diet for 20 days) juveniles (5.5 ¡Ó 0.5 g) were still alive; while all non-BG-treated shrimp died. In order to quantify the effectiveness of BG to WSSV, juveniles (6.5 ¡Ó 0.4 g) were fed diets containing graded levels of BG. The results showed that shrimp fed the diet containing BG 10 g/kg for 20 days had the highest (P<0.001) survival rate (42 %) among all groups. Shrimp that received diets supplemented with BG at a dosage >2 g/kg recuperated 9 ~ 12 days after WSSV challenge; while the group fed diets with no or 1 g/kg BG suffered from rapid decrease in total haemocyte count, phagocytic activity, phenoloxidase, O2-, superoxide dismutase (SOD) production and subsequent high mortality. The results in this study showed that b-1,3-glucan is effective in enhancing the phagocytic activity, phenoloxidase, O2- and SOD productions and consequently the resistance of postlarval, juvenile, subadult and brooder P. monodon against vibriosis and viral infections. Since prolonged use of BG, even at optimal dietary levels, decreased the immunity of the shrimp, care therefore must be taken to maximize its effectiveness. A cycle of dietary BG supplement of 2 ~ 10 g/kg diet for 20 days with an intermission of 10 days may serve the purposes.
62

THE POLYKETIDE ORIGINS OF CANNABINOIDS IN CANNABIS SATIVA

2013 October 1900 (has links)
Phytocannabinoids are the active substances responsible for the medicinal and psychotropic effects of Cannabis sativa. Although the bioactivity of cannabis and its preparations have been known for millennia, several steps in the biosynthetic pathway leading to phytocannabinoids remain unclear. Phytocannabinoids are prenylated resorcylic acids which are formed in specialized plant organs called glandular trichomes. Following the analysis of a pre-generated cannabis trichome cDNA library, a type III polyketide synthase (tetraketide synthase; TKS) was identified and assayed, yielding three major compounds, hexanoyl triacetic acid lactone (HTAL), pentyl diacetic acid lactone (PDAL), and olivetol, yet no resorcylic acid was detected. This lack of resorcylic acid in enzyme assays has instigated the characterization of TKS and a search for putative cyclases in the cannabis trichome cDNA library, and involved protein pulldown, co-immunoprecipitation, and co-assay experiments. These experiments led to the discovery of a novel polyketide cyclase protein named olivetolic acid cyclase (OAC) responsible for the proper cyclization of a polyketide intermediate produced by TKS. This thesis shows that TKS assays conducted with OAC produce olivetolic acid (OA), an intermediate required during the biosynthesis of cannabinoids. The TKS/OAC spatial relationship was also investigated following the creation of fluorescent fusion proteins which show that the enzymes co-localized in vivo when viewed with confocal microscopy. Furthermore, yeast two-hybrid assays using TKS and OAC were performed to establish whether the enzymes physically interact. Finally, an attempt to determine the responsible amino acids involved in OAC’s mechanism was conducted by comparing the activity of single point OAC mutants with the wild-type OAC. Based on the available data, mechanisms for the production of HTAL, PDAL, olivetol, and OA are proposed.
63

OPTIMIZING CANNABIS SATIVA CULTIVATION TO INCREASE HIGH ADDED-VALUE COMPOUNDS IN SEED AND THRESHING RESIDUE

CALZOLARI, DAVIDE 27 March 2018 (has links)
Il rinnovato interesse nella coltivazione della canapa industriale non è stato supportato da studi approfonditi e generalmente si basa su esperienze dirette di coltivazione. Questo studio si prefigge come obbiettivo quello di sfruttare tutte la parti della pianta di canapa per migliorare l’economicità complessiva della sua coltivazione tramite l’uso di tecniche agronomiche e di pratiche post-raccolta. La Cannabis sativa ha un vasto campo di applicazioni, tra cui le più promettenti in termini di ritorno economico sono il cosmetico e il farmaceutico. I composti naturali più interessanti della Cannabis sono i cannabinoidi non-psicoattivi cannabidiolo (CBD) e cannabigerolo (CBG) presenti in elevate concentrazioni nelle foglie e nelle brattee di Cannabis. Altri metaboliti secondari prodotti dalla canapa e di grande interesse sono le cannflavine, una classe di prenil-flavonoidi caratteristico di questa specie. Nel primo e nel secondo capitolo la dinamica temporale di accumulo dei metaboliti secondari ad elevato valore aggiunto è stata monitorata per alcune delle varietà più comuni di canapa industriale ed è stata determinata la produzione potenziale di questi composti. Nel terzo capitolo una collezione di semi di canapa è stata valutata per le caratteristiche morfologiche e per il contenuto e la qualità dell’olio. Concludendo questo studio contribuisce allo sviluppo di una coltivazione della canapa per le molteplici destinazioni d’uso dei semi e del fitocomplesso. / Rapidly growing interest into industrial hemp cultivation is not supported by strong data and generally is referred to a limited experience on field cultivation. This study aims to exploit all the parts of hemp plant, in order to ameliorate the overall economy of its cultivation and by providing information on agronomic management and post-harvest operations. Cannabis sativa has a wide range of industrial applications and the most promising, in terms of economic revenues, are the cosmetic and pharmaceutics. The most interesting phytochemicals in Cannabis are the cannabinoids, in particular the non-intoxicating compounds cannabidiol (CBD) and cannabigerol (CBG), present at high concentration in the leaves and bracts of Cannabis. Some other promising secondary metabolites of hemp are cannflavins, a class of prenyl-flavonoids characteristic of this species. In the first and second chapter the time course accumulation of high added-value compounds was monitored for some of the most common industrial hemp cultivars, and the potential production was assessed. In the third chapter a collection of hemp seeds was evaluated for its morphological characteristics and for its oil content and quality. In conclusion this thesis contributes to a further development of multipurpose hemp cultivation for seed and phytocomplex production.
64

Role kanabinoidního systému v neurobiologii a léčbě psychotických onemocnění - experimentální studie v animálních modelech psychóz / The role of cannabinoid system in neurobiology and therapy of psychotic disorders - an experimental study in animal models of psychosis

Nováková, Pavlína January 2014 (has links)
Throughout the scientific world the topic of cannabis usage and its link with psychosis seems to be discussed intensively. Considering the fact that the Czech Republic is a country with one of the highest prevalence of cannabis usage in the world it becomes a sensitive issue even in our circumstances. In the theoretical part of the work we attempted to review current knowledge of a link between cannabinoid system, canabis usage and psychosis and to point out possible future therapeutic potential of cannabinoids in the treatment of psychotic diseases. In the practical part of the work we focused on verification of propsychotic features of THC in animal model with particular attention to validation of acute subcutaneous admonistration of this drug as a novel cannabinoid model of psychosis. At the same time we tried to elucidate antipsychotic effect of CBD in this model. We tested these hypotheses in two behavioral tests (open field test, PPI ASR) and electrophysiologically (quantitative EEG). The whole analysis is enriched with pharmacokinetic data from subcutanneous and oral administration of cannabinoids. Powered by TCPDF (www.tcpdf.org)
65

Dopady dlouhodobého užívání konopných látek / Effects of long-term use of hemp substances

Horynová, Rebecca January 2021 (has links)
The thesis was divided into two parts. The first part deals with selected long-term impacts of cannabis use and basic concepts such as history, methods of application, use or legislation. In order to understand the whole issue, the basic components of the cannabis plant and their effects. The main part of the theory was then devoted to the possibilities of social work in the field of addiction, but also health complications and therapeutic effects of cannabis. The first part was built on a professional basis literature that addresses this topic. As the work dealt with a very current topic, the latest HARP treatment program was also mentioned. In the second part of the work semi-structured interviews were performed in order to confirm the theoretical part of the work and bring a certain authenticity to the work. The goal was to offer to the reader comprehensive information about cannabis in one place, clearly and transparently. The negatives and the positives that this plant can cause as a result of use were analyzed.
66

Marijuana Use in Opioid Exposed Pregnancy Increases Risk of Preterm Birth

Shah, Darshan S., Turner, Emmitt L., Chroust, Alyson J., Duvall, Kathryn L., Wood, David L., Bailey, Beth A. 01 January 2021 (has links)
Background: The prevalence of opioid use disorder has increased across the United States, but the rural population of Appalachia has been disproportionately impacted. Concurrently, the slow, but steady progress in the legalization of marijuana may be affecting perception of marijuana use in pregnancy. However, marijuana use in pregnancy has been associated with adverse perinatal outcomes. Concomitant use of opioids and marijuana in pregnancy has not been evaluated. Objective: The primary aim of the study was to evaluate the association between confirmed marijuana use in late pregnancy and preterm birth in opioid-exposed pregnancies. Methodology: A retrospective chart review was conducted that included all births from July 2011 to June 2016 from 6 delivery hospitals in South-Central Appalachia. Out of 18,732 births, 2368 singleton pregnancies indicated opioid use and met remaining inclusion criteria, with 108 of these mothers testing positive for marijuana at delivery. Independent sample t-test and Chi-Square analyses compared marijuana and non-marijuana exposed groups on maternal and neonatal outcomes. Regression analyses controlled for confounding variables in predicting neonatal abstinence syndrome (NAS), NICU admission, preterm birth, small for gestational age, and low birth weight outcomes as shown in Table 1. Results: Neonates born to marijuana-positive women in opioid-exposed pregnancy were more likely to be born preterm, small for gestational age, have low birth weight, and be admitted to NICU. After statistically controlling for parity, marital status, tobacco and benzodiazepine use, preterm birth and low birth weight remained statistically significant with aOR of 2.35 (1.30–4.24) and 2.01 (1.18–3.44), respectively. Conclusions: Maternal use of marijuana in any opioid-exposed pregnancy may increase risk of preterm birth and low-birth weight infants. Prospective studies need to examine the dose and timing of marijuana and opioid use in pregnancy to better delineate perinatal effects. Nonetheless, pregnant women using opioids, including recommended medication assisted treatment for opioid use disorder, should be educated about the risks of concurrent marijuana use during pregnancy and may need to be counseled to abstain from marijuana use during pregnancy for an optimal outcome.
67

THCmania : An Anthropological Exploration of the First Legal Canadian Grow Cup

Barbosa Ponce, Nina Tamara 01 February 2023 (has links)
This thesis is an anthropological exploration of the first legal Canadian Grow Cup (3 years after legalization (October 17, 2018)). It takes a sensory anthropology approach to 'knowing' from practical activity. This approach acknowledges that senses/sensing do not belong to one category, instead, "our sensory perception is inextricable from the cultural categories that we use to give meaning to sensory experiences in social and material interactions" (Pink 2015, 7). Taking this approach aims to address the current legal framework that reduces cannabis to its molecular compounds. The methodological approach is centred around an apprenticeship with an experienced home grower, whom I met online and who agreed to guide me throughout my participation in the grow cup. The organization of the thesis follows my movements through the apprenticeship situated both online and in my mentor's garden in West Ottawa, Ontario. Having to abide by winning criteria based on THC and Terpene metrics, this thesis offers arguments and critique of the current conjoint legal/ public health/ industry framework. The latter framework is in line with mainstream pharmacology, which advocates the need to use purified substances as they are considered more specific and safe. However, I critique this approach of 'knowing' cannabis through the cannabis cup as the "effects" and quality of whole derived cannabis products are quantified and standardized based on a percentage number associated with two out of 100+ molecular compounds. This creates a new phenomenon, shaping cultivation practices focused on single molecule percentage numbers. Therefore, I ask how does a skilled home grower know/sense cannabis, and how does the contest criteria constrain (or not) the home grower's ways of knowing/ sensing cannabis? Answering these questions aims to understand the sensorial ways of knowing cannabis. As such, this thesis does not deal with standardization or metrics directly. Instead, attention is oriented towards what escapes the contest-winning criteria and standardization, my curiosity resting in ways of 'knowing' directly from what is evoked through practical activity.
68

A Label-Free Electrochemical Biosensing Approach for Modern Diagnostics Using Screen-Printed Electrodes

Grewal, Rehmat January 2024 (has links)
Electrochemical biosensors are renowned for their ability to detect a wide range of analytes in biological fluids for clinical diagnosis. The implementation of biomarkers in electrochemical biosensors for clinical diagnosis is essential for the specific and accurate diagnosis of the disease with high sensitivity and selectivity. Therefore, this thesis evaluates the challenges pertaining to the stability, reproducibility, and obtaining a low limit of detection for the internal/external biomarkers associated with two distinct electrochemical biosensors. The first study tackles the challenge of detecting low analyte concentrations in a label-free biosensor. It introduces an innovative label-free electrochemical biosensing method for the detection of glycosylated hemoglobin (HbA1c) and C-reactive protein (CRP) to predict Coronary Heart Disease (CHD) progression using tailored redox probes, proposing a dual biomarker biosensing platform for future research. Calibration curves reveal an LOD of 5 mg/mL in PBS (8) FeCN (II) and 6 mg/mL in SB for a linear range of 0 – 30 mg/mL of HbA1c. Similarly, an LOD of 0.007 mg/mL and 0.008 mg/mL in PBS (7.4) PcA-NO2 and SB, respectively, is reported for a linear range of 0 – 0.05 mg/mL of CRP. The second study focuses on stabilizing a biomolecule-free sensor for the ultra-low detection of Δ9-tetrahydrocannabinol (THC) in roadside testing. Pre-depositing THC, an external biomarker for drug-impaired driving, onto the biosensor's working electrode enhances its interaction with analytes. However, THC's oxidative nature compromises sensor stability during manufacturing. Consequently, optimal electrode storage conditions were explored, indicating frozen storage as ideal for up to six months, effectively preventing THC oxidation at -18°C, while degradation occurs at 4°C. Modified electrodes stored under optimal conditions exhibit improved calibration curves when exposed to various THC samples. / Thesis / Master of Applied Science (MASc) / An electrochemical biosensor is a sensing device with the ability to detect biological species via the transduction of a specific biological event into electrochemical signals. These sensors are extremely useful for the detection of analytes in biological fluids for clinical diagnostics, to determine the presence or absence of diseases. This manuscript addresses the challenges associated with the stability, reproducibility, and the low limits of detection associated with screen-printed carbon electrodes used in electrochemical biosensing. Subsequently, due to the strong correlation between glycated hemoglobin (HbA1c) and C-reactive protein (CRP) to connote the risk of contracting coronary heart disease (CHD), the manuscript presents a novel label-free electrochemical biosensing method for the detection of HbA1c and CRP with low detection limits. Secondly, the manuscript identifies ambient storage conditions for the long-term stability of a biomolecule-free sensing device for the roadside detection of ultra-low concentrations of Δ9-tetrahydrocannabinol (THC).
69

Caractériser l'effet des cannabinoïdes sur la réponse nociceptive et identifier les cibles moléculaires chez Caenorhabditis elegans

Boujenoui, Fatma 08 1900 (has links)
Ce projet de recherche porte sur l’étude de la régulation des systèmes cannabinoïdes et vanilloïdes chez Caenorhabditis elegans (C. elegans), dans le but d’évaluer les effets antinociceptifs du tétrahydrocannabinol (THC) et du cannabidiol (CBD). C. elegans est un modèle largement utilisé pour étudier la nociception, visant principalement à caractériser les réponses nociceptives induites par le THC et le CBD, ainsi qu’à identifier les mécanismes et les cibles moléculaires impliqués. Les résultats des études sur l’utilisation du cannabis dans le traitement de la douleur chronique chez les mammifères sont controversés. Cette recherche vise à étudier l’effet du CBD et du THC sur la réponse nociceptive chez C. elegans et à approfondir la compréhension des mécanismes pharmacologiques sous-jacents. La méthodologie consiste à quantifier l’effet antinociceptif du CBD et du THC chez C. elegans par la méthode de la thermotaxie. Les nématodes sauvages (N2) étaient exposés à des concentrations croissantes de phytocannabinoïdes pour évaluer la relation concentration-effet. D’autres tests étaient effectués sur des souches mutantes exprimant des récepteurs cannabinoïdes et vanilloïdes afin d’identifier préalablement leurs cibles. Enfin, les analyses protéomiques et bioinformatiques seront effectuées pour identifier les voies de signalisation et les processus biologiques induits par l’interaction entre les phytocannabinoïdes et leurs cibles. Cette étude démontre l’activité antinociceptive du CBD et du THC chez C. elegans avec des effets rémanents pour THC, en ciblant respectivement le vanilloïde pour le CBD et le cannabinoïde pour les systèmes THC. Les analyses protéomiques et bio-informatiques mettent en évidence des différences significatives dans leurs voies de signalisation et leurs processus biologiques. / The objective of this research project was to focus on studying the regulation of cannabinoid and vanilloid systems in Caenorhabditis elegans (C. elegans) to evaluate the anti-nociceptive effects of tetrahydrocannabinol (THC) and cannabidiol (CBD). C. elegans is a widely used model for studying nociception, with the main objective being to characterize nociceptive responses induced by THC and CBD, as well as identify the underlying molecular mechanisms and targets involved. Recent studies on the use of cannabis for the treatment of chronic pain in mammals have shown controversial results. This research aims to investigate the effect of CBD and THC on the nociceptive response in C. elegans and understand the underlying pharmacological mechanisms. The methodology consisted in quantifying the antinociceptive effect of CBD and THC in C. elegans using the thermotaxis method. WT(N2) were exposed to decreasing concentrations of phytocannabinoids to evaluate the dose and effect relationship. Further tests performed on mutant expressing cannabinoid and vanilloid receptors allowed preliminarily identification of their targets. Finally, proteomic and bioinformatics analyses were used to identify the signaling pathways and biological processes induced by these phytocannabinoids. The result of this study confirmed the antinociceptive effect of CBD and THC in C. elegans, with a remanent effect of THC. This effect is mediated by the vanilloid system for CBD and the cannabinoid system for THC, respectively. Also, proteomics and bioinformatics analyses revealed significant differences in signaling pathways and biological processes.
70

EXAMINING EFFECTS OF LIGHT QUALITY ON CANNABIS AND THE CANNABIS APHID (PHORODON CANNABIS)

Eze Pojmann Ezeonyilo (14237201) 12 December 2022 (has links)
<p>  </p> <p>Environmental conditions, like light quality and herbivory, can induce changes in plant physiology. Light quality can be manipulated using LEDs (light emitting diodes) to improve crop quality and yield in horticultural production. The manipulation of light quality has also been utilized in the management of agricultural insect pests. Previous research has provided evidence that changes in light quality can have effects on the growth and chemistry of cannabis crops (<em>Cannabis spp.</em>). Varieties of cannabis are grown for the production of the valued cannabinoids CBD and THC. Pest of cannabis include herbivorous arthropods that reduce hemp yield and quality. Arthropod herbivory can induce chemical and physical changes in plants. This thesis further investigates the role of light quality on both cannabis biology and the crop-pest interaction between cannabis and the cannabis aphid (<em>Phorodon cannabis</em>). In the experiments described herein, the effects of light quality and <em>P. cannabis </em>herbivory on cannabis were assessed by measuring impact on biomass accumulation, yield, and the production of CBD and THC. The effects of light quality on the life history traits of <em>P. cannabis </em>were also measured. Cannabis grown under red-blue light quality saw a reduction in vegetative growth but no reduction in yield. Light treatments had no measured effect on the concentrations of CBD and THC in the cannabis buds. Aphid herbivory decreased bud yield but increased vegetative growth. Aphid herbivory reduced the concentration of both CBD and THC in cannabis bud tissue. Under blue-rich light quality, <em>P. cannabis </em>experienced higher reproductive rates when compared to red-blue and full-spectrum lighting. </p>

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