| 1. |
- Adewumi, Tosin, et al.
(författare)
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AfriWOZ: Corpus for Exploiting Cross-Lingual Transfer for Dialogue Generation in Low-Resource, African Languages
- 2023
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Ingår i: IJCNN 2023 - International Joint Conference on Neural Networks, Conference Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781665488686 - 9781665488679
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Konferensbidrag (refereegranskat)abstract
- Dialogue generation is an important NLP task fraught with many challenges. The challenges become more daunting for low-resource African languages. To enable the creation of dialogue agents for African languages, we contribute the first high-quality dialogue datasets for 6 African languages: Swahili, Wolof, Hausa, Nigerian Pidgin English, Kinyarwanda & Yorùbá. There are a total of 9,000 turns, each language having 1,500 turns, which we translate from a portion of the English multi-domain MultiWOZ dataset. Subsequently, we benchmark by investigating & analyzing the effectiveness of modelling through transfer learning by utilziing state-of-the-art (SoTA) deep monolingual models: DialoGPT and BlenderBot. We compare the models with a simple seq2seq baseline using perplexity. Besides this, we conduct human evaluation of single-turn conversations by using majority votes and measure inter-annotator agreement (IAA). We find that the hypothesis that deep monolingual models learn some abstractions that generalize across languages holds. We observe human-like conversations, to different degrees, in 5 out of the 6 languages. The language with the most transferable properties is the Nigerian Pidgin English, with a human-likeness score of 78.1%, of which 34.4% are unanimous. We freely provide the datasets and host the model checkpoints/demos on the HuggingFace hub for public access.
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| 2. |
- Adeyemi, Ahmed, et al.
(författare)
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Continuous Flow Synthesis under High-Temperature/High-Pressure Conditions Using a Resistively Heated Flow Reactor
- 2017
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Ingår i: Organic Process Research & Development. - : AMER CHEMICAL SOC. - 1083-6160 .- 1520-586X. ; 21:7, s. 947-955
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Tidskriftsartikel (refereegranskat)abstract
- A cheap, easy-to-build, and effective resistively heated reactor for continuous flow synthesis at high temperature and pressure is herein presented. The reactor is rapidly heated directly using, an electric current and is capable of rapidly delivering temperatures and pressures up to 400 degrees C and 200 bar, respectively. High-temperature and high-pressure applications of this reactor were safely performed and demonstrated by selected transformations such as esterifications, transesterifications, and direct carboxylic acid to nitrile reactions using supercritical ethanol, methanol, and acetonitrile. Reaction temperatures were between 300 and 400 degrees C with excellent conversions and good to excellent isolated product yields. Examples of Diels-Alder reactions were also carried out at temperatures up to 300 degrees C in high yield. No additives or catalysts were used in the reactions.
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| 3. |
- Adeyemi, Ahmed, 1986-
(författare)
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Palladium(0)-Catalyzed Synthesis of Spirocycles and Supercritical Chemistry using a Resistively Heated Flow Reactor
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This doctoral thesis focusses on an effective and selective approach to the synthesis of spirocycles using palladium(0)-catalyzed Mizoroki-Heck reactions. In addition, selective and efficient chemistry was highlighted by the design and evaluation of a novel resistively heated system for continuous flow (CF) synthesis for high-temperature and high-pressure applications.Paper I described the design and evaluation of a novel resistively heated CF system. The design of a low-cost, simple, robust, and effective CF system involving a resistively heated steel reactor capable of delivering 400 °C and 200 bar was reported. The reactor was evaluated with esterification, transesterification and direct carboxylic acid to nitrile conversions using supercritical ethanol, methanol and acetonitrile respectively. Diels-Alder reactions under neat conditions were also carried out at high temperature and pressure.Paper II reported the synthesis of spirooxindoles by a selective application of the palladium(0)-catalyzed Mizoroki-Heck spirocyclization. The precursors for the reaction were synthesized by coupling 2-iodoanilines with esters derived from enantiomerically pure (+)-Vince lactam decorated with the bulky, directing 2,5-dimethylpyrrole protecting group. Ten different spirooxindoles were reported with good yields and high regio- and stereoselectivity. Functionalization of a synthesized spirooxindole was done by a palladium(0)-catalyzed alkoxycarbonylation, followed by selective deprotections.In Paper III, ether precursors were synthesized from (+)-Vince lactam, via a Mitsunobu reaction with the corresponding iodophenols. The precursors were later subjected to conditions for intramolecular Mizoroki-Heck reaction. Overall, 12 spiroethers were synthesized in useable yields, regioselectivity up to 98% and with excellent diastereoselectivity (d.e.>98%). Further functionalization to mono-protected rigidified amino acids was also demonstrated.
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| 4. |
- Adeyemi, Ahmed
(författare)
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Regio- and Stereo-Selective Synthesis of Allylic Spiroethers (Spirobenzofuranes) via Intramolecular Mizoroki-Heck Reaction
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Palladium(0)-catalyzed intramolecular annulation of twelve 1,3-disubstituted cyclopentenes, derived from (+)-vince lactam, resulted in 5-exo cyclizations, furnishing a series of 2,5-dimethyl-1-((3R,4'S)-2H-spiro[benzofuran-3,1'-cyclopentan]-2'-en-4'-yl)-1H-pyrroles in excellent diastereoselectivities and useful isolated yields. The double bond migration process, following the arylpalladium insertion, was controlled by fine-tuning of the reaction system, providing regioselectivities of up to 98:2. The selective Mizoroki-Heck reaction was used as the key transformation for preparing two new spirocyclic monoprotected amino acids as single diastereoisomers.
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| 5. |
- Adeyemi, Ahmed, et al.
(författare)
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Regio- and Stereoselective Synthesis of Allylic Spiroethers (Spirobenzofuranes) via an Intramolecular Mizoroki-Heck Reaction
- 2020
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 85:12, s. 7648-7657
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Tidskriftsartikel (refereegranskat)abstract
- The palladium(0)-catalyzed intramolecular annulation of 12 1,3-disubstituted cyclopentenes, derived from (+)-vincelactam, resulted in 5-exo cyclizations which furnished a series of 2,5-dimethyl-14(3R,4'S)-2H-spiro[benzofuran-3,1'-cyclopentan]2'-en-4'-yl)-1H-pyrroles in excellent diastereoselectivities and useful isolated yields. The double bond migration process that followed the arylpalladium insertion was controlled by a fine-tuning of the reaction system, which provided regioselectivities of up to 98:2. The selective Mizoroki-Heck reaction was used as the key transformation for preparing two new spirocyclic monoprotected amino acids as single stereoisomers.
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| 6. |
- Adeyemi, Ahmed, et al.
(författare)
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Regio- and Stereoselective Synthesis of Spirooxindoles via Mizoroki-Heck Coupling of Aryl Iodides
- 2019
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Ingår i: Synlett. - : GEORG THIEME VERLAG KG. - 0936-5214 .- 1437-2096. ; 30:1, s. 82-88
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Tidskriftsartikel (refereegranskat)abstract
- A method for highly regio- and stereoselective intramolecular Mizoroki-Heck 5- exo cyclization of aryl iodides to the corresponding spirooxindoles has been developed. Electron-rich and electron-deficient aryl iodide precursors were selectively ring-closed with high stereoselectivity and good yields. The double-bond position in the cyclopentene ring was controlled by careful choice of reaction conditions. These rare spiro compounds were further functionalized to rigidified unnatural amino acid derivatives by a subsequent gas-free Pd(0)-catalyzed alkoxycarbonylation, followed by selective O - and N -deprotections.
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| 7. |
- Lucero-Prisno III, Don Eliseo, et al.
(författare)
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Drug shortage crisis in Sudan in times of COVID-19
- 2020
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Ingår i: Public Health in Practice. - : Elsevier. - 2666-5352. ; 1
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Sudan is witnessing severe drugs, medicines, and medical supplies shortages, which present a major impediment to the provision of emergency healthcare services. Drug insecurity in Sudan is as a result of several accumulated factors, primarily due to worsening economic condition, inappropriate pricing policy, privatization of the pharmaceutical sector, poor manufacturing and weak weak weregulatory system. These could threaten patient health through replacement of highly efficacious medicines with less effective alternatives and by impacting the scheduling of urgent medical operations and procedures. Drug and medicine shortages are of catastrophic impact especially amid the current epidemic of COVID-19 where these are salient needs. Efforts should be quickly directed to ensure immediate access to pharmaceutical products and other essential health commodities. Effective policies on drug importation, production, pricing, and distribution should be established to avoid the consequences of an impending crisis.
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