75 research outputs found

    An Alternative Tissue Culture Media for Potato (Solanum tuberosum L.) Micro Propagation

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    The cumbersome nature of tissue culture technique contributes to the low adoption of the technique. This work aims at developing an accessible alternative tissue culture medium for potato micro propagation. The inorganic components of the conventional MS medium were replaced with a common source of nitrogen, phosphorus and potassium (NPK) to regenerate in vitro plantlets of six improved Cameroonian potato varieties selected from meristem-derived plantlets. These varieties included: Cipira, Mafo, Bambui wonder, Irad 2005, Jacob 2005 and Tubira. Five (5) nodes each per replicate per variety were cultured on both media and allowed to grow at a temperature of 21 ºC and 16hrs/day photoperiod for 28 days.Number of nodes sprouting, number of nodes rooting, plant height, and number of nodes per plantlet were recorded weekly in 4 weeks. Results shows that both media regenerated vigorous plantlets with shoots and roots. Using the Statistical Package for Social Science (SPSS), analysis of variance revealed slight significant differences (p≤0.05) between varieties and media in terms of sprouting and rooting Height of plantlets on NPK medium ranged from 29.85 mm (Cipira) to 45.25 mm (Irad 2005) meanwhile, on MS medium it ranged from 47.93 mm (Bambui Wonder) to 65.70 mm (Jacob 2005). Average number of nodes ranged from 2.59 (Tubira) to 3.63 (Mafo) on fertilizer medium while on MS medium it ranged from 2.70 (Irad 2005) to 4.20 (No significant difference at p≤0.05). in conclusion; the developing countries can replace the inorganic components of MS medium with inorganic fertilizer (NPK) for in vitro multiplication of potato

    SELFIES and the future of molecular string representations

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    Artificial intelligence (AI) and machine learning (ML) are expanding in popularity for broad applications to challenging tasks in chemistry and materials science. Examples include the prediction of properties, the discovery of new reaction pathways, or the design of new molecules. The machine needs to read and write fluently in a chemical language for each of these tasks. Strings are a common tool to represent molecular graphs, and the most popular molecular string representation, Smiles, has powered cheminformatics since the late 1980s. However, in the context of AI and ML in chemistry, Smiles has several shortcomings—most pertinently, most combinations of symbols lead to invalid results with no valid chemical interpretation. To overcome this issue, a new language for molecules was introduced in 2020 that guarantees 100% robustness: SELF-referencing embedded string (Selfies). Selfies has since simplified and enabled numerous new applications in chemistry. In this perspective, we look to the future and discuss molecular string representations, along with their respective opportunities and challenges. We propose 16 concrete future projects for robust molecular representations. These involve the extension toward new chemical domains, exciting questions at the interface of AI and robust languages, and interpretability for both humans and machines. We hope that these proposals will inspire several follow-up works exploiting the full potential of molecular string representations for the future of AI in chemistry and materials science

    SELFIES and the future of molecular string representations

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    Artificial intelligence (AI) and machine learning (ML) are expanding in popularity for broad applications to challenging tasks in chemistry and materials science. Examples include the prediction of properties, the discovery of new reaction pathways, or the design of new molecules. The machine needs to read and write fluently in a chemical language for each of these tasks. Strings are a common tool to represent molecular graphs, and the most popular molecular string representation, SMILES, has powered cheminformatics since the late 1980s. However, in the context of AI and ML in chemistry, SMILES has several shortcomings -- most pertinently, most combinations of symbols lead to invalid results with no valid chemical interpretation. To overcome this issue, a new language for molecules was introduced in 2020 that guarantees 100\% robustness: SELFIES (SELF-referencIng Embedded Strings). SELFIES has since simplified and enabled numerous new applications in chemistry. In this manuscript, we look to the future and discuss molecular string representations, along with their respective opportunities and challenges. We propose 16 concrete Future Projects for robust molecular representations. These involve the extension toward new chemical domains, exciting questions at the interface of AI and robust languages and interpretability for both humans and machines. We hope that these proposals will inspire several follow-up works exploiting the full potential of molecular string representations for the future of AI in chemistry and materials science

    Being Moved: Louis XIV’s Triumphant Tenderness and the Protestant Object

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    This essay examines the place of affect in Le Triomphe de la Religion, a text from 1687 that praises Louis XIV for the Revocation of the Edict of Nantes and the forced conversion of French Protestants. It explores the role of the material object in this text and contrasts it with seventeenth-century Protestant fears about the seductive power of Catholic objects. Drawing on the work of affect theory, it suggest how attention to the strange relation between emotion and the material object might better illuminate our sense of what it meant to be religiously different in absolutist France

    Neighbourhood immigration, health care utilization and outcomes in patients with diabetes living in the Montreal metropolitan area (Canada): a population health perspective

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    Abstract: Background: Understanding health care utilization by neighbourhood is essential for optimal allocation of resources, but links between neighbourhood immigration and health have rarely been explored. Our objective was to understand how immigrant composition of neighbourhoods relates to health outcomes and health care utilization of individuals living with diabetes. Methods: This is a secondary analysis of administrative data using a retrospective cohort of 111,556 patients living with diabetes without previous cardiovascular diseases (CVD) and living in the metropolitan region of Montreal (Canada). A score for immigration was calculated at the neighbourhood level using a principal component analysis with six neighbourhood-level variables (% of people with maternal language other than French or English, % of people who do not speak French or English, % of immigrants with different times since immigration (<5 years, 5–10 years, 10–15 years, 15–25 years)). Dependent variables were all-cause death, all-cause hospitalization, CVD event (death or hospitalization), frequent use of emergency departments, frequent use of general practitioner care, frequent use of specialist care, and purchase of at least one antidiabetic drug. For each of these variables, adjusted odds ratios were estimated using a multilevel logistic regression. Results: Compared to patients with diabetes living in neighbourhoods with low immigration scores, those living in neighbourhoods with high immigration scores were less likely to die, to suffer a CVD event, to frequently visit general practitioners, but more likely to visit emergency departments or a specialist and to use an antidiabetic drug. These differences remained after controlling for patient-level variables such as age, sex, and comorbidities, as well as for neighbourhood attributes like material and social deprivation or living in the urban core. Conclusions: In this study, patients with diabetes living in neighbourhoods with high immigration scores had different health outcomes and health care utilizations compared to those living in neighbourhoods with low immigration scores. Although we cannot disentangle the individual versus the area-based effect of immigration, these results may have an important impact for health care planning

    Foreign Investment Screening in Germany and France

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    The role of neck afferents in subjective orientation in the visual and tactile sensory modalities.

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    International audienceWe studied the influence of neck afferents on the perception of orientation. In Experiment 1, we investigated the effect of head tilt on the subjective vertical in both the visual and tactile modalities. The results showed that head tilt triggers an Aubert effect in the visual modality and a M?r effect in the tactile modality. Significant positive correlations between the two adjustment modalities were restricted to head tilt to the left. In Experiment 2, we investigated the role of neck afferents on tactile orientation in seated and supine positions. The results showed that, in the supine position, the tactile E-effect was twice as large as in the seated position. These experiments confirm that tactile perception of orientation is affected by neck afferents, and show that the influence of neck afferents is limited by relevant gravitational cues

    Effects of salinity on growth, water content and distribution of Na+ and K+ in the organs of Avicennia germinans L. seedlings

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    Effects of 4 different concentrations of NaCl on plant height, on water content and on the distribution of monovalent cations (Na + and K +) in organs of Avicennia germinans seedlings in semi-controlled conditions were investigated. After 4 weeks of cultivation, results showed that 200 mmoles sodium chloride reduced the height of leaves, but roots and stems growth was stimulated at 100 mmoles of NaCl. A high retention rate of sodium was noted in seedling epicotyl axes, contributing to delay the invasion of young leaves, thereby preventing toxic effects of the ion. Adaptation of mature leaves to the salt stress was found to be associated with succulence, which was achieved by the absorption of large quantities of water and K +. In leaves, uptake of K + was not affected by the NaCl concentration in the medium. As a result, absorption of Na + and K+ reduces the water potential, and consequently increases the water content in the studied organs. The high concentrations of Na + and K + in the leaves suggested that these ions might be the principal mineral elements responsible for the osmotic adjustment in the resistance of A. germinans to salinity stress. Keywords: mineral nutrition salinity, ionic transport, Avicennia germinans Cameroon Journal of Experimental Biology Vol. 1(1) 2005: 21-2
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