64 research outputs found
Multiplication and Conservation of Threatened Medicinal Plant Arnica montana L. by in vitro Techniques
An efficient and reproducible in vitro protocol for mass production of the threatened medicinal plant Arnica montana L. (Asteraceae) was developed. The effectiveness of various combinations of plant growth regulators on A. montana clonal multiplication was assessed, using seedlings stems as initial explants. Among 12 tested nutrient media, the optimum one (MS supplemented with 1.0 mg/l BAP and 0.1 mg/l IAA) increased the organogenesis frequency up to 95% in the best origin, with mean number of shoots per explant 4.25 for 5 weeks. Sub-cultivations on this medium every 4 weeks led to increase of the propagation rate as in the fifth subculture the average number of shoots per explant reached 12.32+-0.82. Rooting of uniform in vitro shoots was 100% successful on half strength MS medium supplemented with 0.5 mg/l IBA. The ex vitro adapted plants showed 90% survival, and were further acclimatized to two mountain ex situ collections. Plants looked healthy and true-to- type and began to bloom in the second or the third year. In addition, a successful protocol for slow-growth storage of in vitro A. montana cultures was elaborated, after testing 8 media with mannitol or sorbitol. The medium 1/2 MS containing 3% sorbitol and 2% sucrose was chosen as the best one, efficiently retarding the growth of the in vitro plantlets, thus allowing 6-month maintenance without sub-cultivation. The developed in vitro protocols could be of great value for commercial propagation and sustainable conservation of this threatened medicinal plant
Improving Yield and Quality-Related Physiological Characteristics of Lettuce by Integrated Inorganic and Organic Fertilizers Management
The research aims to obtain more information on the nitrogen metabolism and nutraceutical properties of two types Lactuca sativa L. var. crispa L. type Batavia cv. \u27Maritima\u27 and type Lollo Rosso cv. \u27Tuska\u27 and one type Lactuca sativa L. var. capitata L. cv. \u27Winter butterhead\u27 under the implementation of different organic fertilizers. In this respect, the main goal of our study is to define a proper macro- and micronutrients source which has the most beneficial effect on yield as well as on various quality parameters of lettuce. The experiment was conducted in an unheated greenhouse in two consecutive seasons (2018/2019 and 2019/2020) under all the requirements for organic production. Four organic fertilizers (Italpollina”, “Arcobaleno”, “Lumbrical” and “EKOprop” were studied. From obtained results, it could be concluded that the impact of fertilizers on lettuce growth and quality has possessed cultivar dependence. The fertilizing with natural fertilizers, so that the nutrients they possess are strictly comprised of animal-based materials (dry bird manure “Italpolina”, mix from bovine, horse and chicken manure “Arkobaleno”) or compost (lumbricompost made by Red Californian worms “Lumbrical”) of the three lettuce cultivars resulted in lower plant FW and yield, compared with NPK fertilizing. Only fertilizing with a mix of different beneficial microorganisms leads to the same plant FW and yield as fertilizing with inorganic fertilizer. Based on the higher plant FW and yield of all three lettuce cultivars the treatment with the fertilizer composed with beneficial microorganisms can be substituted with the treatment with inorganic NPC fertilizer. “EKOprop” fertilizing showed the lowest leaf nitrate concentration which correlated with higher activity of nitrogen assimilating enzyme nitrate reductase
Improving Yield and Quality-Related Physiological Characteristics of Lettuce by Integrated Inorganic and Organic Fertilizers Management
The research aims to obtain more information on the nitrogen metabolism and nutraceutical properties of two types Lactuca sativa L. var. crispa L. type Batavia cv. \u27Maritima\u27 and type Lollo Rosso cv. \u27Tuska\u27 and one type Lactuca sativa L. var. capitata L. cv. \u27Winter butterhead\u27 under the implementation of different organic fertilizers. In this respect, the main goal of our study is to define a proper macro- and micronutrients source which has the most beneficial effect on yield as well as on various quality parameters of lettuce. The experiment was conducted in an unheated greenhouse in two consecutive seasons (2018/2019 and 2019/2020) under all the requirements for organic production. Four organic fertilizers (Italpollina”, “Arcobaleno”, “Lumbrical” and “EKOprop” were studied. From obtained results, it could be concluded that the impact of fertilizers on lettuce growth and quality has possessed cultivar dependence. The fertilizing with natural fertilizers, so that the nutrients they possess are strictly comprised of animal-based materials (dry bird manure “Italpolina”, mix from bovine, horse and chicken manure “Arkobaleno”) or compost (lumbricompost made by Red Californian worms “Lumbrical”) of the three lettuce cultivars resulted in lower plant FW and yield, compared with NPK fertilizing. Only fertilizing with a mix of different beneficial microorganisms leads to the same plant FW and yield as fertilizing with inorganic fertilizer. Based on the higher plant FW and yield of all three lettuce cultivars the treatment with the fertilizer composed with beneficial microorganisms can be substituted with the treatment with inorganic NPC fertilizer. “EKOprop” fertilizing showed the lowest leaf nitrate concentration which correlated with higher activity of nitrogen assimilating enzyme nitrate reductase
The Impact of Population Heterogeneities and Disease Interventions on Herd Immunity: A Case Study of the COVID-19 Pandemic in Ontario
In epidemiology, herd immunity refers to the population level of immunity required to prevent or extinguish a large disease outbreak. In models with homogeneously mixing assumptions and without demographic structures, the herd immunity level may be different from that in heterogeneous models. With the COVID-19 pandemic in Ontario as a case study, a comprehensive deterministic mathematical model of disease spread with age and contact pattern variations was developed to examine the required herd immunity for different variants and compare with theoretical values obtained using homogeneous assumptions. The effects of non-pharmaceutical (testing/isolation of silent infections) interventions and vaccination on epidemic progression and herd immunity were investigated. With the inclusion of age and contact pattern structures, the resulting herd immunity level required to end an epidemic under the assumptions of long-term protection (without re-infection) is lower than theoretical values, even for more transmissible variants. While waning immunity and re-infection results in an oscillation in herd immunity levels in the population, subsequent epidemic peaks are less amplified, suggesting that even with increased variant transmissibility, infections of any variant allow for population immunity to rise, leading to an endemic state
Enzyme and Non-Enzyme Antioxidant Activity of Micro Propagated Cape Gooseberry (Physalis peruviana L.)
Several studies have represented data on in vitro clonal multiplication of Physalis peruviana L. using different nutrient media supplemented with diverse growth regulators, but there is still scarce information on the changes in the antioxidant potential of the plants subjected to micropropagation. The present research investigates the effect of various plant growth regula-tors on the antioxidant activity of micropropagated P. peruviana L. The seedling explants of P. peruviana (L.) were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of the studied citokines, 6-benzylaminopurine (BAP), zeatin and thidiazuron (TDZ).The micro-shoots produced normal roots within two weeks of cultivation on half-strength MS medium supplemented with the auxins indole-3-butyric acid (IBA) or indole-3-acetic acid (IAA) at concentrations 0.1 mg L-1 and 0.5 mg L-1, respectively. The most efficient plant rooting was achieved with plants grown on half-strength MS medium with 0.1 mg L-1 IBA (number of shoots per explant 12.1 with a shoot height 5.2 cm) as well as 0.1 mg L-1 IAA (number of shoots per explant 10.4 with a shoot height 7.3 cm) after four weeks of cultivation. The reported micropropagation protocol here is characterized by a rapid proliferation and facilitated rooting of the microshoots. The multiple plants were successfully adapted showing 100% survival rate after two months of ex vitro growth. The changes of en-zyme and non-enzyme antioxidant activity were found to depend on the concentration of the used cytokinins. At the lower concentration of 0.5 mg L-1 of studied cytikinins the antioxidant capacity was characterized by a higher concentration of metabolites with antioxidant poten-tial. The higher cytokinin concentration of 0.1 mg L-1 used in the micropropagation procedure resulted in higher antioxidant enzyme activity. The influence of different growth regulators on the antioxidant potential of micropropagated P. peruviana L. plantlets is discussed
Evaluating an Interspecific Helianthus annuus × Helianthus nuttallii Line for Use in Sunflower Breeding Program
Interspecific cross was made between the common sunflower inbred line HA89 and an accession of wild Helianthus nuttallii (2n=2x=34) resistant to the most harmful disease complex and tolerant to drought and high temperature. The recombinant inbred line was a BC1F15 progeny. The most remarkable feature observed was the vigorous plant habit that manifests itself in measurable morphological characters such as increment plant height, stem diameter and diameter of the head. The line was non-branched (monocephalic) without anthocyanin pigmentation and possessed good agronomic characteristics. Along with the morphological and reproductive traits, some biochemical characteristics related to antioxidant activity were associated to wide hybridization. The overall characteristics of HA-Hnutt line make it a useful plant material for research on interspecific hybridization in Helianthus genus
MODELLING AND LONG TERM DYNAMICS OF CRAB CAVITIES IN THE LHC
Abstract The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) aims to achieve an integrated luminosity of 250-300 fb −1 per year. This upgrade includes the use of crab cavities to mitigate the geometric loss of luminosity arising from the beam crossing angle. The tight space constraints at the location of the cavities leads to cavity designs which are axially non-symmetric and have a potentially significant effect on the long term dynamics and dynamic aperture of the LHC. In this paper we present the current status of advanced modelling of crab cavities
Co-operation, Contestation and Complexity in Post-Conflict Security Sector Reform
Security Sector Reform (SSR) remains a key feature of peacebuilding interventions and is usually undertaken by a state alongside national and international partners. External actors engaged in SSR tend to follow a normative agenda that often has little regard for the context in post-conflict societies. Despite recurrent criticism, SSR practices of international organisations and bilateral donors often remain focused on state institutions, and often do not sufficiently attend to alternative providers of security or existing normative frameworks of security. This article provides a critical overview of existing research and introduces the special issue on “Co-operation, Contestation and Complexity in Post-Conflict Security Sector Reform”. We explore three aspects that add an important piece to the puzzle of what constitutes effective SSR. First, the variation of norm adoption, norm contestation and norm imposition in post-conflict countries that might explain the mixed results in terms of peacebuilding. Second, the multitude of different security actors within and beyond the state which often leads to multiple patterns of co-operation and contestation within reform programmes. And third, how both the multiplicity of and tension between norms and actors further complicate efforts to build peace or, as complexity theory would posit, influence the complex and non-linear social system that is the conflict-affected environment
Botulismo em crianças: Revisão integrativa / Botulism in children: Integrative review
Objetivo: Identificar em estudos teóricos as características clínicas da contaminação por Clostridium botulinum em crianças. Metodologia: Trata-se de um estudo descritivo e exploratório, de abordagem quantitativa por meio de revisão bibliográfica. Foram analisados 06 artigos nas bases de dados Lilacs e Medline, no período de 2008 a 2017. Resultados: Os artigos eram de nacionalidades diferentes; três relatavam casos de surto de botulismo alimentar familiar; um relato de contaminação por Clostridium botulinum em um menino aborígene de Taiwan. Casos de botulismo em ferida são raros, mas encontrou-se relato de dois artigos que descrevem lesões por madeira, um em face e outro na borda cubital esquerda. Conclusão: Percebe-se a ocorrência, mesmo que isolada, em diversos países. Os indivíduos que apresentam intoxicação por Clostridium botulinum desenvolvem neuropatia progressiva necessitando por vezes de intubação orotraqueal, além de outros procedimentos invasivos. São relatados dois óbitos. Cuidados com os tipos de alimentos consumidos e o armazenamento destes são fundamentais
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