ASSESSMENT OF PERIODS OF SAND PRIMING AND HYDRO-PRIMING ON THE GERMINATION OF AFRICAN EBONY (Diospyros mespiliformis Hochst)

Diospyros mespiliformis (Hochst) is a multipurpose, agro-forestry tree species with diverse environmental and ecological significances. However, low percentage germination associated with its seeds has limited its domestication. To overcome this challenge, there is need to adopt cheap, fast, safe, natural and adoptable physiological techniques such as sand priming and hydro-priming. There is paucity of quantified information on natural and safe methods of relieving dormancy as sand priming and hydro-priming. Most of methods of breaking dormancy as use of acid are not simple, safe and adoptable by farmers who practices agro-forestry. In the light of this, these experiments were conducted to assess the periods of sand priming (0, 2, 4, 6 and 8 weeks) and hydro-priming (0, 2, 4, 6 and 8 weeks) on the germination of D. mespiliformis. Both experiments were laid down in completely randomized design with four replicates. Mean germination times were calculated, and result revealed that a significant increase in percentage germination was recorded with increasing periods of exposing seeds to sand priming up to four weeks. The percentage germination ranged between 28%-93.25% for control (0) and four weeks sand priming respectively. Least value of 8.92 day was recorded for mean germination time of control (0 sand priming). A significant increase in percentage germination was recorded with increasing hours of hydro-priming up to 24 hours. The percentage germination was ranged between 25% - 100% for control (0) hour to 24 hours. Highest germination percentages were recorded in seeds subjected to sand priming for 4weeks (93.25%) and those hydro-primed for 24hours (100%). These results are recommended for mass production of D. mespiliformis in agro-forestry nurseries. &nbsp

STORABILITY AND PRE-SOWING TREATMENTS OF AFRICAN STAR APPLE (CHRYSOPHYLLUM ALBIDUM G. Don) SEEDS

Chrysophyllum  albidum is a prominent, indigenous, economic fruit tree species found in compound farm agro-forestry systems . Investigation was conducted to overcome difficulty in germination and storability of C. albidum seeds in the forest nursery of Federal University of Agriculture, Abeokuta, Nigeria. The trial employed a 3x3 factorial experiment with three replications laid out in a completely randomized design to determine the effect of seed coat treatments including clipping at 2mm from distal, circumference and micropyle end; dipping in 10% sulphuric acid and no seed coat treatments and durations of seed storage 1, 5 and 9 days on the germination of C. albidum seeds. Pre-sowing and storage treatments significantly (p < 0.05) affected the germination of seeds. Percentage germination ranged from 17% to 61% for clipping to no seed coat treatment. Highest germination of 61% was recorded for seeds not pre-sowed. The percentage germination ranged from 16% to 60% for seeds stored for nine days to those stored for one day. Highest germination of 60% was recorded for seeds stored for one day. A significant (p < 0.05) decrease in percentage germination was recorded with increasing days of storage. The result of interaction effect revealed that highest germination of 86% was recorded for seeds stored for 5days without pre-sowing treatments. Storing of seeds for 5days is recommended for mass production of C. albidum seedlings in agro-forestry nursery. &nbsp

EFFECT OF THE BOTANICAL PELLETINGS AND STORAGE PERIODS ON THE GERMINATION OF AFRICAN STAR APPLE (CHRYSOPHYLLUM ALBIDUM G. DON) SEEDS

There is paucity of quantified information on the simple, safe and affordable methods of invigorating seeds and storage of recalcitrant seeds. In this light, investigation was conducted in the screen house of the Federal College of Forestry Mechanization, Afaka, Kaduna on the effect of the botanical pelletings and storage periods of C. albidum seeds. A seed pellet is a coating, usually of clay mixed with other inerts, which streamlines the size, shape, and uniformity of a small, non-round seed. A split-plot experimental design with four (4) replications was laid down to assess the effect of botanical pelletings with the leaves of six agro-forestry tree species (Gliricidia sepium, Leucaena leucocephala, Albizia lebbeck, Acacia auriculiformis, Parkia biglobosa and Dacryodus edulis) and storage periods (0, 1, 2, 3 and 4 weeks) on the germination of C. albidum seeds stored in the refrigerator.  The data were subjected to analysis of variance (ANOVA)using SAS (2003)software. The percentage germination of seeds pelletized with G. sepium, L leucocephala, A. lebbeck, A. auriculiformis, P. biglobosa and D. edulis ranged between 18.50%-42.00%, 8.3%-13.60%, 5.2%-18.80%, 3.6% -16.30%, 5.0%-14.30%, and 2.5%-11.10%, for 2-8 weeks respectively. The percentage germination of seeds stored for 0, 1, 2, 3 and 4 weeks ranged between 8.50%-21%, 4.70%-24.58%, 9.42%-22.75%, 8.67%-19.58% and 3.33%-8.83% respectively. The percentage germination of seeds pelletized with the leaves of G. sepium, L. leucocephala, A. lebbeck, A. auriculiformis, P. biglobosa and D. edulis and stored for storage periods ranged between 1-65%, 0-30%, 0-30.5%, 1-25%, 0-20% and 0-30%. Botanical pelletings and storage periods significantly (P<0.05) enhanced the germination of C. albidum seeds. Highest germination percentage of 65% was recorded for seeds pelletized with G. sepium leaves and stored for 3 weeks. The research therefore recommends seed pelleting with G. sepium leaves and storage for 3 weeks for mass production of C. albidum seedlings for agro-forestry systems. &nbsp

BLOOM+1: Adding Language Support to BLOOM for Zero-Shot Prompting

The BLOOM model is a large publicly available multilingual language model, but its pretraining was limited to 46 languages. To extend the benefits of BLOOM to other languages without incurring prohibitively large costs, it is desirable to adapt BLOOM to new languages not seen during pretraining. In this work, we apply existing language adaptation strategies to BLOOM and benchmark its zero-shot prompting performance on eight new languages in a resource-constrained setting. We find language adaptation to be effective at improving zero-shot performance in new languages. Surprisingly, we find that adapter-based finetuning is more effective than continued pretraining for large models. In addition, we discover that prompting performance is not significantly affected by language specifics, such as the writing system. It is primarily determined by the size of the language adaptation data. We also add new languages to BLOOMZ, which is a multitask finetuned version of BLOOM capable of following task instructions zero-shot. We find including a new language in the multitask fine-tuning mixture to be the most effective method to teach BLOOMZ a new language. We conclude that with sufficient training data language adaptation can generalize well to diverse languages. Our code is available at https://github.com/bigscience-workshop/multilingual-modeling

MasakhaPOS: Part-of-Speech Tagging for Typologically Diverse African languages

In this paper, we present AfricaPOS, the largest part-of-speech (POS) dataset for 20 typologically diverse African languages. We discuss the challenges in annotating POS for these languages using the universal dependencies (UD) guidelines. We conducted extensive POS baseline experiments using both conditional random field and several multilingual pre-trained language models. We applied various cross-lingual transfer models trained with data available in the UD. Evaluating on the AfricaPOS dataset, we show that choosing the best transfer language(s) in both single-source and multi-source setups greatly improves the POS tagging performance of the target languages, in particular when combined with parameter-fine-tuning methods. Crucially, transferring knowledge from a language that matches the language family and morphosyntactic properties seems to be more effective for POS tagging in unseen languages

Early Life Exposure to Aflatoxin B1 in Rats: Alterations in Lipids, Hormones, and DNA Methylation among the Offspring

Aflatoxins are toxic compounds produced by molds of the Aspergillus species that contaminate food primarily in tropical countries. The most toxic aflatoxin, aflatoxin B1 (AFB1), is a major cause of hepatocellular carcinoma (HCC) in these countries. In sub-Saharan Africa, aflatoxin contamination is common, and perinatal AFB1 exposure has been linked to the early onset of HCC. Epigenetic programming, including changes to DNA methylation, is one mechanism by which early life exposures can lead to adult disease. This study aims to elucidate whether perinatal AFB1 exposure alters markers of offspring health including weight, lipid, and hormone profiles as well as epigenetic regulation that may later influence cancer risk. Pregnant rats were exposed to two doses of AFB1 (low 0.5 and high 5 mg/kg) before conception, throughout pregnancy, and while weaning and compared to an unexposed group. Offspring from each group were followed to 3 weeks or 3 months of age, and their blood and liver samples were collected. Body weights and lipids were assessed at 3 weeks and 3 months while reproductive, gonadotropic, and thyroid hormones were assessed at 3 months. Prenatal AFB1 (high dose) exposure resulted in significant 16.3%, 31.6%, and 7.5% decreases in weight of the offspring at birth, 3 weeks, and 3 months, respectively. Both doses of exposure altered lipid and hormone profiles. Pyrosequencing was used to quantify percent DNA methylation at tumor suppressor gene Tp53 and growth-regulator H19 in DNA from liver and blood. Results were compared between the control and AFB1 exposure groups in 3-week liver samples and 3-week and 3-month blood samples. Relative to controls, Tp53 DNA methylation in both low- and high-dose exposed rats was significantly decreased in liver samples and increased in the blood (p < 0.05 in linear mixed models). H19 methylation was higher in the liver from low- and high-exposed rats and decreased in 3-month blood samples from the high exposure group (p < 0.05). Further research is warranted to determine whether such hormone, lipid, and epigenetic alterations from AFB1 exposure early in life play a role in the development of early-onset HCC

MasakhaNER 2.0: Africa-centric Transfer Learning for Named Entity Recognition

African languages are spoken by over a billion people, but are underrepresented in NLP research and development. The challenges impeding progress include the limited availability of annotated datasets, as well as a lack of understanding of the settings where current methods are effective. In this paper, we make progress towards solutions for these challenges, focusing on the task of named entity recognition (NER). We create the largest human-annotated NER dataset for 20 African languages, and we study the behavior of state-of-the-art cross-lingual transfer methods in an Africa-centric setting, demonstrating that the choice of source language significantly affects performance. We show that choosing the best transfer language improves zero-shot F1 scores by an average of 14 points across 20 languages compared to using English. Our results highlight the need for benchmark datasets and models that cover typologically-diverse African languages

Deletion of a Malaria Invasion Gene Reduces Death and Anemia, in Model Hosts

Malaria parasites induce complex cellular and clinical phenotypes, including anemia, cerebral malaria and death in a wide range of mammalian hosts. Host genes and parasite ‘toxins’ have been implicated in malarial disease, but the contribution of parasite genes remains to be fully defined. Here we assess disease in BALB/c mice and Wistar rats infected by the rodent malaria parasite Plasmodium berghei with a gene knock out for merozoite surface protein (MSP) 7. MSP7 is not essential for infection but in P. falciparum, it enhances erythrocyte invasion by 20%. In vivo, as compared to wild type, the P. berghei Δmsp7 mutant is associated with an abrogation of death and a decrease from 3% to 2% in peak, circulating parasitemia. The Δmsp7 mutant is also associated with less anemia and modest increase in the size of follicles in the spleen. Together these data show that deletion of a single parasite invasion ligand modulates blood stage disease, as measured by death and anemia. This work is the first to assess the contribution of a gene present in all plasmodial species in severe disease