Search

Your search keyword '"Niang, A"' showing total 11,414 results
Start Over Author "Niang, A"
11,414 results on '"Niang, A"'

1. Compositional data analysis for modeling and forecasting mortality with the {\alpha}-transformation

Author

Lim, Han Ying, Pathmanathan, Dharini, and Dabo-Niang, Sophie

Subjects
Statistics - Applications
Abstract

Mortality forecasting is crucial for demographic planning and actuarial studies, particularly for predicting population ageing rates and future longevity risks. Traditional approaches largely rely on extrapolative methods, such as the Lee-Carter model and its variants which use mortality rates as inputs. In recent years, compositional data analysis (CoDA), which adheres to summability and non-negativity constraints, has gained increasing attention from researchers for its application in mortality forecasting. This study explores the use of the {\alpha}-transformation as an alternative to the commonly applied centered log-ratio (CLR) transformation for converting compositional data from the Aitchison simplex to unconstrained real space. The {\alpha}-transformation offers greater flexibility through the inclusion of the {\alpha} parameter, enabling better adaptation to the underlying data structure and handling of zero values, which are the limitations inherent to the CLR transformation. Using age-specific life table death counts for males and females in 31 selected European countries/regions from 1983 to 2018, the proposed method demonstrates comparable performance to the CLR transformation in most countries with improved forecast accuracy in some cases. These findings highlight the potential of the {\alpha}-transformation as a competitive alternative transformation technique for real-world mortality data within a non-functional CoDA framework., Comment: 16 pages, 4 tables, 3 figures

Published
2025

2. Tree populations show low regeneration of valued species in West Africa

Author

Lykke, Anne Mette, Rømer, Nanna, Gonzalez, Patrick, Kakaï, Romain Glèlè, Rabiou, Habou, Amegnaglo, Kossi Béssan, Ganaba, Souleymane, Sambou, Bienvenu, Niang, Fatimata, Herault, Bruno, Guuroh, Reginald Tang, Ouoba, Paulin, Yaméogo, Jérôme T, Traoré, Lassina, Sinsin, Brice, Amahowe, Ogoudje Isidore, Bay, Signe S, Houehanou, Thierry D, Houessou, Laurent G, Gouwakinnou, Gérard N, Yetein, Marius H, Tankoano, Boalidioa, Ouédraogo, Amadé, Ouédraogo, Issaka, Taita, Paulette, Amani, Bienvenu HK, Coulibaly, Brahima, Kouyaté, Amadou Malé, van Damme, Patrick, Vanhove, Wouter, Mahamane, Ali, Bonache, Carolina, Sambou, Simon, Soumana, Idrissa, Amani, Abdou, Maârouhi, Inoussa Maman, and Barfod, Anders S

Subjects
Ecological Applications, Biological Sciences, Ecology, Environmental Management, Environmental Sciences, Regenerative Medicine, Life on Land, Conservation, Degradation, Regional analysis, Size class distribution, Sahel and Sudan zones, Tree population structure, Agricultural and Veterinary Sciences, Zoology, Environmental management
Abstract

Tree populations have declined substantially in West Africa in recent decades, raising concerns since trees provide numerous ecosystem goods and services. Regional information on the population status of tree species could guide more effective conservation and regeneration of natural vegetation. Here, we report results of the first regional analysis of tree population structure across the Sahel and Sudan zones, a meta-study of vegetation inventories, including 23,586 individual trees sampled across nine countries. We evaluated current status and forecast future trends of 16 species and one genus of trees of ecological and socio-economic importance. Size class distribution (SCD) reflects the population structure of an individual species and can provide early warning of composition change and population decline. SCD is analysed widely at a local scale, but analysis at a regional scale is needed to detect widespread population changes. Many native species lacked trees in the smaller size classes, implying unsustainable populations and future decline. Some species show sound regeneration at the regional scale, but high variation among sites. Eight species, including Adansonia digitata and Afzelia africana, show regional declines in regeneration and risks of future extirpations. Four of these severely lack regeneration. Protected areas show higher tree regeneration, but protected status did not assure good regeneration. Our results identify priority tree species across West Africa, indicate a more urgent need for conservation and regeneration of native tree species, and highlight the benefit of effective conservation. More widespread protection could increase tree populations, conserving biodiversity, and ecosystem services essential for people's livelihoods.

Published
2025

3. Defect density of states of tin oxide and copper oxide p-type thin-film transistors

Author

Mattsson, Måns J., Niang, Kham M., Parker, Jared, Meeth, David J., Wager, John F., Flewitt, Andrew J., and Graham, Matt W.

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Applied Physics
Abstract

The complete subgap defect density of states (DoS) is measured using the ultrabroadband (0.15 to 3.5 eV) photoconduction response from p-type thin-film transistors (TFTs) of tin oxide, SnO, and copper oxide, Cu$_2$O. The TFT photoconduction spectra clearly resolve all bandgaps that further show the presence of interfacial and oxidized minority phases. In tin oxide, the SnO majority phase has a small 0.68 eV bandgap enabling ambipolar or p-mode TFT operation. By contrast, in copper oxide TFTs, an oxidized minority phase with a 1.4 eV bandgap corresponding to CuO greatly reduces the channel hole mobility at the charge accumulation region. Three distinct subgap DoS peaks are resolved for the copper oxide TFT and are best ascribed to copper vacancies, oxygen-on-copper antisites, and oxygen interstitials. For tin oxide TFTs, five subgap DoS peaks are observed and are similarly linked to tin vacancies, oxygen vacancies, and oxygen interstitials. Unipolar p-type TFT is achieved in tin oxide only when the conduction band-edge defect density peak ascribed to oxygen interstitials is large enough to suppress any n-mode conduction. Near the valence band edge in both active channel materials, the metal vacancy peak densities determine the hole concentrations, which further simulate the observed TFT threshold voltages., Comment: 11 pages, 8 figures

Published
2024

5. Spatial Principal Component Analysis and Moran Statistics for Multivariate Functional Areal Data

Author

Pathmanathan, Dharini, Dabo, Issa-Mbenard, Khoo, Tzung Hsuen, Ali-Hassan, Alaa, and Dabo-Niang, Sophie

Subjects
Statistics - Methodology
Abstract

In this article, we present the bivariate and multivariate functional Moran's I statistics and multivariate functional areal spatial principal component analysis (mfasPCA). These methods are the first of their kind in the field of multivariate areal spatial functional data analysis. The multivariate functional Moran's I statistic is employed to assess spatial autocorrelation, while mfasPCA is utilized for dimension reduction in both univariate and multivariate functional areal data. Through simulation studies and real-world examples, we demonstrate that the multivariate functional Moran's I statistic and mfasPCA are powerful tools for evaluating spatial autocorrelation in univariate and multivariate functional areal data analysis.

Published
2024

6. Forecasting mortality rates with functional signatures

Author

Yap, Zhong Jing, Pathmanathan, Dharini, and Dabo-Niang, Sophie

Subjects
Statistics - Methodology
Abstract

This study introduces an innovative methodology for mortality forecasting, which integrates signature-based methods within the functional data framework of the Hyndman-Ullah (HU) model. This new approach, termed the Hyndman-Ullah with truncated signatures (HUts) model, aims to enhance the accuracy and robustness of mortality predictions. By utilizing signature regression, the HUts model is able to capture complex, nonlinear dependencies in mortality data which enhances forecasting accuracy across various demographic conditions. The model is applied to mortality data from 12 countries, comparing its forecasting performance against variants of the HU models across multiple forecast horizons. Our findings indicate that overall the HUts model not only provides more precise point forecasts but also shows robustness against data irregularities, such as those observed in countries with historical outliers. The integration of signature-based methods enables the HUts model to capture complex patterns in mortality data, making it a powerful tool for actuaries and demographers. Prediction intervals are also constructed with bootstrapping methods, Comment: 40 pages, 26 figures, 9 tables

Published
2024
Full Text
View/download PDF

7. Generalized functional dynamic principal component analysis

Author

Khoo, Tzung Hsuen, Dabo, Issa-Mbenard, Pathmanathan, Dharini, and Dabo-Niang, Sophie

Subjects
Statistics - Methodology
Abstract

In this paper, we explore dimension reduction for time series of functional data within both stationary and non-stationary frameworks. We introduce a functional framework of generalized dynamic principal component analysis (GDPCA). The concept of GDPCA aims for better adaptation to possible nonstationary features of the series. We define the functional generalized dynamic principal component (GDPC) as static factor time series in a functional dynamic factor model and obtain the multivariate GDPC from a truncation of the functional dynamic factor model. GDFPCA uses a minimum squared error criterion to evaluate the reconstruction of the original functional time series. The computation of GDPC involves a two-step estimation of the coefficient vector of the loading curves in a basis expansion. We provide a proof of the consistency of the reconstruction of the original functional time series with GDPC converging in mean square to the original functional time series. Monte Carlo simulation studies indicate that the proposed GDFPCA is comparable to dynamic functional principal component analysis (DFPCA) when the data generating process is stationary, and outperforms DFPCA and FPCA when the data generating process is non-stationary. The results of applications to real data reaffirm the findings in simulation studies.

Published
2024

8. Humans in Africa’s wet tropical forests 150 thousand years ago

Author

Ben Arous, Eslem, Blinkhorn, James A., Elliott, Sarah, Kiahtipes, Christopher A., N’zi, Charles D., Bateman, Mark D., Duval, Mathieu, Roberts, Patrick, Patalano, Robert, Blackwood, Alexander F., Niang, Khady, Kouamé, Eugénie Affoua, Lebato, Edith, Hallett, Emily, Cerasoni, Jacopo N., Scott, Erin, Ilgner, Jana, Alonso Escarza, Maria Jesús, Guédé, Francois Yodé, and Scerri, Eleanor M. L.

Published
2025
Full Text
View/download PDF

11. Edge- AI and Internet of Things for Intelligent Systems: Architectures, Applications and Future Perspectives

Author

Diop, Fatou, Faye, Babacar Mbaye, Niang, Ibrahima, Akan, Ozgur, Editorial Board Member, Bellavista, Paolo, Editorial Board Member, Cao, Jiannong, Editorial Board Member, Coulson, Geoffrey, Editorial Board Member, Dressler, Falko, Editorial Board Member, Ferrari, Domenico, Editorial Board Member, Gerla, Mario, Editorial Board Member, Kobayashi, Hisashi, Editorial Board Member, Palazzo, Sergio, Editorial Board Member, Sahni, Sartaj, Editorial Board Member, Shen, Xuemin, Editorial Board Member, Stan, Mircea, Editorial Board Member, Jia, Xiaohua, Editorial Board Member, Zomaya, Albert Y., Editorial Board Member, Sere, Abdoulaye, editor, Sie, Oumarou, editor, and Saeed, Rashid A., editor

Published
2025
Full Text
View/download PDF

12. On the lack of X-ray pulsation in most neutron star low-mass X-ray binaries

Author

Niang, Ndiogou, Ertan, Unal, Gencali, Ali Arda, Toyran, Ozan, Ulubay, Ayse, Devlen, Ebru, Alpar, M. Ali, and Gugercinoglu, Erbil

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We have investigated whether the lack of X-ray pulsations from most neutron star (NS) low-mass X-ray binaries (LMXBs) could be due to the extension of their inner disc to the NS surface. To estimate the inner disc radii, we have employed the model, recently proposed to account for the torque reversals of LMXBs. In this model, the inner disc radius depends on the spin period as well as the dipole moment and the mass inflow rate of the disc. Our model results indicate that most LMXBs have mass accretion rates above the minimum critical rates required for the inner disc to reach down to the NS surface and thereby quench the pulsed X-ray emission. For most sources X-ray pulsations are allowed when the period decreases below a certain critical value. For the same parameters, the model is also consistent with the observed X-ray luminosity ranges of the individual accreting millisecond X-ray pulsars (AMXPs). The paucity of AMXPs compared to the majority population of non-pulsing LMXBs is explained, as well as the fact that AMXPs are transient sources., Comment: 10 pages, 5 figures, accepted for publication in MNRAS

Published
2024

13. Uncovering Data Across Continua: An Introduction to Functional Data Analysis

Author

Dabo-Niang, Sophie and Frévent, Camille

Subjects
Mathematics - Statistics Theory
Abstract

In a world increasingly awash with data, the need to extract meaningful insights from data has never been more crucial. Functional Data Analysis (FDA) goes beyond traditional data points, treating data as dynamic, continuous functions, capturing ever-changing phenomena nuances. This article introduces FDA, merging statistics with real-world complexity, ideal for those with mathematical skills but no FDA background.

Published
2024

15. Adapting wild biodiversity conservation approaches to conserve agrobiodiversity

Author

Jago, S., Elliott, K. F. V. A., Tovar, C., Soto Gomez, M., Starnes, T., Abebe, W., Alexander, C., Antonelli, A., Baldaszti, L., Cerullo, G., Cockel, C., Collison, D., Cowell, C., Delgado, R., Demissew, S., Devenish, A., Dhanjal-Adams, K., Diazgranados, M., Drucker, A. G., Dulloo, M. E., Erland, B. M., Fadika, S., Huang, W., Inwood, K., Jones, S. K., Klitgaard, B. B., Lebbie, A., Lim, F. K. S., Lulekal, E., Morales-Rozo, C., Niang, F., Nic Lughadha, E., Oliveira, R. P., Ortega-Argueta, A., Pironon, S., Plummer, J. F., Ramirez, M., Ryan, P., Simbiano, F. J., Smith, R. J., Stevenson, P. C., Treydte, A. C., Victor, J. E., Weber, O., Williams, C., Yohanna, C. T., Grace, O. M., Darbyshire, I., and Borrell, J. S.

Published
2024
Full Text
View/download PDF

17. Heterogeneous genetic architectures of prostate cancer susceptibility in sub-Saharan Africa

Author

Janivara, Rohini, Chen, Wenlong C., Hazra, Ujani, Baichoo, Shakuntala, Agalliu, Ilir, Kachambwa, Paidamoyo, Simonti, Corrine N., Brown, Lyda M., Tambe, Saanika P., Kim, Michelle S., Harlemon, Maxine, Jalloh, Mohamed, Muzondiwa, Dillon, Naidoo, Daphne, Ajayi, Olabode O., Snyper, Nana Yaa, Niang, Lamine, Diop, Halimatou, Ndoye, Medina, Mensah, James E., Abrahams, Afua O. D., Biritwum, Richard, Adjei, Andrew A., Adebiyi, Akindele O., Shittu, Olayiwola, Ogunbiyi, Olufemi, Adebayo, Sikiru, Nwegbu, Maxwell M., Ajibola, Hafees O., Oluwole, Olabode P., Jamda, Mustapha A., Pentz, Audrey, Haiman, Christopher A., Spies, Petrus V., van der Merwe, André, Cook, Michael B., Chanock, Stephen J., Berndt, Sonja I., Watya, Stephen, Lubwama, Alexander, Muchengeti, Mazvita, Doherty, Sean, Smyth, Natalie, Lounsbury, David, Fortier, Brian, Rohan, Thomas E., Jacobson, Judith S., Neugut, Alfred I., Hsing, Ann W., Gusev, Alexander, Aisuodionoe-Shadrach, Oseremen I., Joffe, Maureen, Adusei, Ben, Gueye, Serigne M., Fernandez, Pedro W., McBride, Jo, Andrews, Caroline, Petersen, Lindsay N., Lachance, Joseph, and Rebbeck, Timothy R.

Published
2024
Full Text
View/download PDF

19. On timelike Bonnet surfaces in Lorentzian 3-manifold

Author

Niang, Athoumane, Ndiaye, Ameth, and Thiandoum, Adama

Subjects
Mathematics - Differential Geometry
Abstract

In this paper we generalized a result of Soley Ersoy and Kemal Eren [10] about Bonnet timelike surface in Minkowski 3-space. We give a necessary and sufficient condition for a surface M in a Lorentzian 3-space to be timelike Bonnet surface. At the end, a theorem of classification of timelike Bonnet surface in a Lorentzian 3-space is given.

Published
2024

21. Annotated checklist of the marine ichthyofauna of Mauritania from shallow-water habitats and artisanal fish markets

Author

Alexander Hans Knorrn, Sidi Mohamed M. Moctar, Moritz Sonnewald, Mamadou Dia, Alioune Niang, and André Freiwald

Subjects
Biodiversity, fisheries, upwelling, West Africa, Biology (General), QH301-705.5
Abstract

Due to their location in a strong upwelling area, Mauritanian waters are one of the most nutrient‑rich and productive areas in the eastern Atlantic Ocean. On the Mauritanian coast, a remarkably high biodiversity consisting of tropical, subtropical, and temperate species with overlapping distributions can be found. This study reports 104 fish species from 53 different families from this area. Overall, the findings indicate Mauritanian waters as a coastal area with high biodiversity and occurrences of several critically endangered elasmobranch species such as Sphyrna lewini (Griffith & Smith, 1834) and Glaucostegus cemiculus (Geoffroy Saint-Hilaire, 1817). Moreover, this survey indicated an urgent need for updates concerning the IUCN Red List classification of several Mauritanian species, which serve as an essential income source for artisanal fishermen in Mauritania.

Published
2025
Full Text
View/download PDF

22. Preoperative mortality risk evaluation in abdominal surgical emergencies: development and internal validation of the NDAR score from a national multicenter audit in Senegal

Author

Abdourahmane Ndong, Adja Coumba Diallo, Lebem Togtoga, Magatte Faye, Pape Mamadou Faye, Ahmed Diouf, Ndiamé Sarr, Abdou Niasse, Aliou Coly Faye, Cheikh Tidiane Mbaye, Mamadou Saidou Bah, Pape Djibril Ndoye, Mohamed Doukoure, Moussa Guira, Cheikh Tidiane Ka, Bathie Massamba Diouf, Thierno Faye, Foulaké Tandian, Thierno Amadou Telly Dialllo, Modou Gaye, Ngueidio Yamingué, Housseynou Kama, Emmanuel Kazubwenge, Mbaye Thiam, Abdou Dahim Diack, Mamadou Arame Ndiaye, Abamou Babara, Cheikh Samb, Cheikh Hameth Badji, Christine Marie Joseph Diouf, Sidy Mouhamed Abdoulaye Fall, Mamadouba Camara, Julien Ibrahima Faye, Abdou Khadre Niang, Pape Souleymane Dieng, Ablaye Ndiaye, Diago Anta Dia, Omar Sow, Abib Diop, Yacine Seye, Ibrahima Souleymane Sitor Sarr, Mohamadou Lamine Gueye, Mohamed Lamine Diao, Philipe Manyacka, Eugène Gaudens Prosper Amaye Diémé, Ibrahima Sall, Oumar Fall, Alamasso Sow, Jacques Noel Tendeng, Ousmane Thiam, Mamadou Seck, Cheikh Diouf, Ibrahima Ka, Alpha Oumar Touré, Balla Diop, Pape Ablaye Ba, Pape Saloum Diop, Mamadou Cissé, Khadim Niang, and Ibrahima Konaté

Subjects
Emergency, Abdomen, Africa, Mortality, Surgery, Score, RD1-811
Abstract

Abstract Introduction Abdominal surgical emergencies have a high mortality rate. Effective management primarily relies on the early identification of patients at high risk of postoperative complications. The objective of our study was to determine the prognostic factors associated with poor outcomes from abdominal surgical emergencies in Senegal and to establish a predictive score for mortality for preoperative risk evaluation (NDAR (New Death Assessment Risk) score). Methodology This was a retrospective national cross-sectional study conducted over one year in 14 regions of Senegal. Adult patients (aged > 15 years) who presented with a traumatic or non-traumatic abdominal surgical emergency were included. The studied variables included clinical and paraclinical data. The variable of interest was death within 30 days of the surgery. Logistic regression was used to identify the factors independently associated with mortality. Risk factors identified after logistic regression analysis were weighted using odds ratio (OR) values rounded to the nearest whole number. The predictive capacity of the score was evaluated by analyzing the ROC (Receiver Operating Characteristic) curve based on the area under the curve (AUC). Results A total of 1114 patient records were included, with a mortality rate of 4.4%. Diagnoses were observed in patients included appendicitis in 39.8% of cases (n = 444), followed by peritonitis in 22.3% (n = 249), intestinal obstruction in 18.5% (n = 205), strangulated hernias in 10.5% (n = 117), and abdominal trauma in 6.1%. Logistic regression, established the following scores: age > 40 years (score 2), ASA status grade 2 or higher (score 1), presence of a positive QSIRS score (score 2), diagnosis of peritonitis (score 2), diagnosis of intestinal obstruction (score 1), and the presence of intestinal necrosis (score 3). The score is positive if the total is strictly greater than 5, indicating a 17.7% risk of mortality. This score had a high predictive capacity with an AUC of 0.7397. Conclusion This study enabled the establishment of a score that allows for the early identification of at-risk patients, even in constrained resource settings, facilitating appropriate perioperative management and timely surgical intervention to reduce the risk of complications. This approach, focused on early recognition of high-risk patients, is crucial for improving clinical outcomes in abdominal surgical emergencies.

Published
2024
Full Text
View/download PDF

23. A Markov-switching spatio-temporal ARCH model

Author

Khoo, Tzung Hsuen, Pathmanathan, Dharini, Otto, Philipp, and Dabo-Niang, Sophie

Subjects
Statistics - Methodology
Abstract

Stock market indices are volatile by nature, and sudden shocks are known to affect volatility patterns. The autoregressive conditional heteroskedasticity (ARCH) and generalized ARCH (GARCH) models neglect structural breaks triggered by sudden shocks that may lead to an overestimation of persistence, causing an upward bias in the estimates. Different regime-switching models that have abrupt regime-switching governed by a Markov chain were developed to model volatility in financial time series data. Volatility modelling was also extended to spatially interconnected time series, resulting in spatial variants of ARCH models. This inspired us to propose a Markov switching framework of the spatio-temporal log-ARCH model. In this article, we discuss the Markov-switching extension of the model, the estimation procedure and the smooth inferences of the regimes. The Monte-Carlo simulation studies show that the maximum likelihood estimation method for our proposed model has good finite sample properties. The proposed model was applied to 28 stock indices data that were presumably affected by the 2015-2016 Chinese stock market crash. The results showed that our model is a better fit compared to that of the one-regime counterpart. Furthermore, the smoothed inference of the data indicated the approximate periods where structural breaks occurred. This model can capture structural breaks that simultaneously occur in nearby locations.

Published
2023

24. Real-Time Enterovirus D68 Outbreak Detection through Hospital Surveillance of Severe Acute Respiratory Infection, Senegal, 2023

Author

Jallow, Mamadou Malado, Mendy, Marie Pedapa, Barry, Mamadou Aliou, Diagne, Moussa Moise, Sagne, Samba Niang, Tall, Fatime, Diouf, Jean Baptisse Niokhor, Ndiaye, Ndiende Koba, Kiori, Davy, Sy, Sara, Goudiaby, Deborah, Loucoubar, Cheikh, Fall, Gamou, Kadjo, Herve, Bessaud, Mael, and Dia, Ndongo

Subjects
Dakar, Senegal (City) -- Health aspects, Diagnosis, Diseases, Causes of, Health aspects, Enterovirus infections -- Diagnosis -- Causes of, Hospital patients -- Diseases, Epidemics -- Causes of -- Senegal, Pediatric communicable diseases -- Diagnosis -- Causes of, Enterovirus diseases -- Diagnosis -- Causes of, Communicable diseases in children -- Diagnosis -- Causes of
Abstract

Enterovirus D68 (EV-D68) has emerged as a major public health concern because of its association with outbreaks of severe acute respiratory illness (SARI), acute flaccid myelitis (AFM), and acute flaccid [...]

Published
2024
Full Text
View/download PDF

27. Fusion regression methods with repeated functional data

Author

Moindjié, Issam-Ali, Preda, Cristian, and Dabo-Niang, Sophie

Subjects
Statistics - Methodology, Mathematics - Statistics Theory
Abstract

Linear regression and classification methods with repeated functional data are considered. For each statistical unit in the sample, a real-valued parameter is observed over time under different conditions related by some neighborhood structure (spatial, group, etc.). Two regression methods based on fusion penalties are proposed to consider the dependence induced by this structure. These methods aim to obtain parsimonious coefficient regression functions, by determining if close conditions are associated with common regression coefficient functions. The first method is a generalization to functional data of the variable fusion methodology based on the 1-nearest neighbor. The second one relies on the group fusion lasso penalty which assumes some grouping structure of conditions and allows for homogeneity among the regression coefficient functions within groups. Numerical simulations and an application of electroencephalography data are presented.

Published
2023

29. Variable effects of non-falciparum species infections on malaria disease severity in high transmission regions in Senegal

Author

Aissatou Diagne, Babacar Souleymane Sambe, Folly Mawulolo Gaba, Ibrahima Sarr, Arona Sabène Diatta, Ousmane Sadio, Serigne Ousmane Mbacké Diaw, Hélène Ataume Mawounge Diatta, Babacar Diouf, Inès Vigan-Womas, Babacar Mbengue, and Makhtar Niang

Subjects
Malaria, Plasmodium species, Diagnostic, Disease severity, Arctic medicine. Tropical medicine, RC955-962
Abstract

Abstract In malaria endemic countries, non-falciparum species are often mixed with Plasmodium falciparum in patients with uncomplicated malaria, and their contribution to malaria severity and death is poorly studied. This study assesses the contribution of non-falciparum species to malaria severity in three regions of Senegal with the highest malaria incidence. We analysed 617 blood samples obtained between 2015 and 2021 from confirmed malaria patients at health facilities in Kedougou, Kolda and Tambacounda in Senegal. Plasmodium species composition was determined by PCR and their distribution were analysed according to age and disease severity, and the relative risk of developing severe malaria. Overall, 94.8% of samples contained P. falciparum either as single or mixed with other species. Non-falciparum P. ovale, P. vivax and P. malariae species were detected in 60.12, 13.61 and 1.62% of samples, respectively. Severe malaria was primarily due to P. falciparum, but co-infection with P. vivax led to a 1.63-fold significant (p = 0.05) increased risk of developing severe malaria, contrasting with the non-significant reduced risk (OR = 0.78; CI 95: 0.55–1.11; p = 0.16) associated with P. ovale infections. Children aged

Published
2024
Full Text
View/download PDF

30. Chronic invasive fungal sinusitis mimicking pseudotumor: A case report

Author

Coumba Gueye, MD, Ibrahima Niang, MD, and Elhadji A. Gueye, MD

Subjects
Invasive fungal sinusitis, Aspergillus flavus, CT, MRI, Medical physics. Medical radiology. Nuclear medicine, R895-920
Abstract

Fungal sinusitis encompasses a wide range of diseases, including both invasive and noninvasive, acute, and chronic forms. The incidence of invasive sinusitis is on the rise, primarily affecting immunocompromised individuals and diabetics. This case report highlights a patient who developed invasive fungal sinusitis despite no other apparent cause of immunosuppression. Imaging studies suggested the diagnosis, confirmed by presence of Aspergillus flavus on mycological culture.

Published
2024
Full Text
View/download PDF

31. A review of the response and the emergency medical team (EMT) deployment following a tanker explosion in Freetown, Sierra Leone

Author

Boniface Oyugi, Ibrahim Franklyn Kamara, Innocent Nuwagira, Robert Musoke, Sulaiman Lakoh, Abdulai Jalloh, Rashidatu Fouad Kamara, Pryanka Relan, Camila Lajolo, René André Macodou Ndiaye, Babacar Niang, Mouhamadou Mansour Fall, Thierno Balde, Flavio Salio, and Mustapha Kabba

Subjects
Sierra Leone, Deployment, Tanker explosion, Response, Emergency medical teams, Special situations and conditions, RC952-1245, Medical emergencies. Critical care. Intensive care. First aid, RC86-88.9
Abstract

Abstract Background On 5 November 2021, a fire incident following a tanker explosion occurred in the Wellington PMB Junction east of Freetown, Sierra Leone, injuring and killing people. WHO facilitated the deployment of international emergency medical teams (EMTs) to support the Ministry of Health (MoH) in providing care to the wounded in four hospitals. Objective In this study, we document Sierra Leone's experience managing the fire incident and the role of EMTs in responding to it. Method This is a cross-sectional After-Action Review (AAR) debrief of the response and deployment, including focus group discussion with WHO and MoH staff (n = 14) in a virtual workshop and document reviews on the response. The results thematically cover the event and the different agencies' responses and a review of EMTs' responses. Results At the onset of the emergency, the National Disaster Management Agency (NDMA) instituted a well-coordinated response mechanism in collaboration with the MoH and managed all response actions, such as medical services, informing partners and the public and coordinating all other agencies. WHO facilitated EMT deployments and mobilised medical supplies and equipment, while the MoH provided accommodation, logistics and coordination. The EMTs dispensed their functions with professionalism, adapted to the environment and available resources, and augmented the care the national health workers provided. They offered additional care: reconstructive surgery, pain management, palliative care, wound care, rehabilitation, physiotherapy and psychosocial counselling, which were initially inadequate at the onset of the disaster. 94 out of 157 patients were discharged home at the end. National clinicians acquired additional skills through the capacity-building activities of EMTs. The community appreciated the teams. Conclusion The government, partners and EMTs were important in the response and worked with speed and political acceptability using the context experience to provide surge support to the country. This experience brought to focus the idea of developing a national EMT in Sierra Leone, which would be useful to help respond even more swiftly. In collaboration with WHO, there is a need to institute further mechanisms to facilitate rapid response and quality-assured deployment of EMTs at regional and sub-regional levels and strengthen to support future responses.

Published
2024
Full Text
View/download PDF

39. The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Author

Clements, Hayley S., Do Linh San, Emmanuel, Hempson, Gareth, Linden, Birthe, Maritz, Bryan, Monadjem, Ara, Reynolds, Chevonne, Siebert, Frances, Stevens, Nicola, Biggs, Reinette, De Vos, Alta, Blanchard, Ryan, Child, Matthew, Esler, Karen J., Hamann, Maike, Loft, Ty, Reyers, Belinda, Selomane, Odirilwe, Skowno, Andrew L., Tshoke, Tshegofatso, Abdoulaye, Diarrassouba, Aebischer, Thierry, Aguirre-Gutiérrez, Jesús, Alexander, Graham J., Ali, Abdullahi H., Allan, David G., Amoako, Esther E., Angedakin, Samuel, Aruna, Edward, Avenant, Nico L., Badjedjea, Gabriel, Bakayoko, Adama, Bamba-kaya, Abraham, Bates, Michael F., Bates, Paul J. J., Belmain, Steven R., Bennitt, Emily, Bradley, James, Brewster, Chris A., Brown, Michael B., Brown, Michelle, Bryja, Josef, Butynski, Thomas M., Carvalho, Filipe, Channing, Alan, Chapman, Colin A., Cohen, Callan, Cords, Marina, Cramer, Jennifer D., Cronk, Nadine, Cunneyworth, Pamela M. K., Dalerum, Fredrik, Danquah, Emmanuel, Davies-Mostert, Harriet T., de Blocq, Andrew D., De Jong, Yvonne A., Demos, Terrence C., Denys, Christiane, Djagoun, Chabi A. M. S., Doherty-Bone, Thomas M., Drouilly, Marine, du Toit, Johan T., Ehlers Smith, David A., Ehlers Smith, Yvette C., Eiseb, Seth J., Fashing, Peter J., Ferguson, Adam W., Fernández-García, José M., Finckh, Manfred, Fischer, Claude, Gandiwa, Edson, Gaubert, Philippe, Gaugris, Jerome Y., Gibbs, Dalton J., Gilchrist, Jason S., Gil-Sánchez, Jose M., Githitho, Anthony N., Goodman, Peter S., Granjon, Laurent, Grobler, J. Paul, Gumbi, Bonginkosi C., Gvozdik, Vaclav, Harvey, James, Hauptfleisch, Morgan, Hayder, Firas, Hema, Emmanuel M., Herbst, Marna, Houngbédji, Mariano, Huntley, Brian J., Hutterer, Rainer, Ivande, Samuel T., Jackson, Kate, Jongsma, Gregory F. M., Juste, Javier, Kadjo, Blaise, Kaleme, Prince K., Kamugisha, Edwin, Kaplin, Beth A., Kato, Humphrey N., Kiffner, Christian, Kimuyu, Duncan M., Kityo, Robert M., Kouamé, N’goran G., Kouete T, Marcel, le Roux, Aliza, Lee, Alan T. K., Lötter, Mervyn C., Lykke, Anne Mette, MacFadyen, Duncan N., Macharia, Gacheru P., Madikiza, Zimkitha J. K., Mahlaba, Themb’alilahlwa A. M., Mallon, David, Mamba, Mnqobi L., Mande, Claude, Marchant, Rob A., Maritz, Robin A., Markotter, Wanda, McIntyre, Trevor, Measey, John, Mekonnen, Addisu, Meller, Paulina, Melville, Haemish I., Mganga, Kevin Z., Mills, Michael G. L., Minnie, Liaan, Missoup, Alain Didier, Mohammad, Abubakr, Moinde, Nancy N., Moise, Bakwo Fils E., Monterroso, Pedro, Moore, Jennifer F., Musila, Simon, Nago, Sedjro Gilles A., Namoto, Maganizo W., Niang, Fatimata, Nicolas, Violaine, Nkenku, Jerry B., Nkrumah, Evans E., Nono, Gonwouo L., Norbert, Mulavwa M., Nowak, Katarzyna, Obitte, Benneth C., Okoni-Williams, Arnold D., Onongo, Jonathan, O’Riain, M. Justin, Osinubi, Samuel T., Parker, Daniel M., Parrini, Francesca, Peel, Mike J. S., Penner, Johannes, Pietersen, Darren W., Plumptre, Andrew J., Ponsonby, Damian W., Porembski, Stefan, Power, R. John, Radloff, Frans G. T., Rambau, Ramugondo V., Ramesh, Tharmalingam, Richards, Leigh R., Rödel, Mark-Oliver, Rollinson, Dominic P., Rovero, Francesco, Saleh, Mostafa A., Schmiedel, Ute, Schoeman, M. Corrie, Scholte, Paul, Serfass, Thomas L., Shapiro, Julie Teresa, Shema, Sidney, Siebert, Stefan J., Slingsby, Jasper A., Sliwa, Alexander, Smit-Robinson, Hanneline A., Sogbohossou, Etotepe A., Somers, Michael J., Spawls, Stephen, Streicher, Jarryd P., Swanepoel, Lourens, Tanshi, Iroro, Taylor, Peter J., Taylor, William A., te Beest, Mariska, Telfer, Paul T., Thompson, Dave I., Tobi, Elie, Tolley, Krystal A., Turner, Andrew A., Twine, Wayne, Van Cakenberghe, Victor, Van de Perre, Frederik, van der Merwe, Helga, van Niekerk, Chris J. G., van Wyk, Pieter C. V., Venter, Jan A., Verburgt, Luke, Veron, Geraldine, Vetter, Susanne, Vorontsova, Maria S., Wagner, Thomas C., Webala, Paul W., Weber, Natalie, Weier, Sina M., White, Paula A., Whitecross, Melissa A., Wigley, Benjamin J., Willems, Frank J., Winterbach, Christiaan W., and Woodhouse, Galena M.

Published
2024
Full Text
View/download PDF

41. Place of urolithiasis in the spectrum of urological pathologies, practices and use of endourological procedures in the management of calculi of the upper urinary tract: results of a survey of referral centres in Africa

Author

Nedjim, Saleh Abdelkerim, Biyouma, Marcella D. C., Kifle, Anteneh Tadesse, Ziba, Ouima Justin Dieudonné, Mahamat, Mahamat Ali, Idowu, Najeem Adedamola, Mbwambo, Orgeness Jasper, Cassel, Ayun, Douglas, Arthur, Kalli, Moussa, Gebreselassie, Kaleab Habtemichael, Khalid, Abdullahi, Wadjiri, Mac Mansou, Hoby, Rambel, Muhawenimana, Emmanuel, Marebo, Toto Shareba, Ngwa-Ebogo, Tagang Titus, Salissou, Mahamane, Adoumadji, Kouldjim, Nzeyimana, Innocent, Odzèbe, Anani Wencesl Sévérin, Barry, Mamadou II, Rimtebaye, Kimassoum, Choua, Ouchemi, Niang, Lamine, Honoré, Berthé, Samnakay, Saeed, Bowa, Kasonde, Lazarus, John, Coulibaly, Noel, Ndoye, Alain Khassim, Makon, Axel Stephane Nwaha, and Aboutaieb, Rachid

Published
2024
Full Text
View/download PDF

43. Erratum to: Production of antihydrogen atoms by 6 keV antiprotons through a positronium cloud

Author

Adrich, P., Blumer, P., Caratsch, G., Chung, M., Cladé, P., Comini, P., Crivelli, P., Dalkarov, O., Debu, P., Douillet, A., Drapier, D., Froelich, P., Garroum, N., Guellati-Khelifa, S., Guyomard, J., Hervieux, P.-A., Hilico, L., Indelicato, P., Jonsell, S., Karr, J.-P., Kim, B., Kim, S., Kim, E.-S., Ko, Y. J., Kosinski, T., Kuroda, N., Latacz, B. M., Lee, B., Lee, H., Lee, J., Lim, E., Liszkay, L., Lunney, D., Manfredi, G., Mansoulié, B., Matusiak, M., Nesvizhevsky, V., Nez, F., Niang, S., Ohayon, B., Park, K., Paul, N., Pérez, P., Regenfus, C., Reynaud, S., Roumegou, C., Roussé, J.-Y., Sacquin, Y., Sadowski, G., Sarkisyan, J., Sato, M., Schmidt-Kaler, F., Staszczak, M., Szymczyk, K., Tanaka, T. A., Tuchming, B., Vallage, B., Voronin, A., van der Werf, D. P., Welker, A., Won, D., Wronka, S., Yamazaki, Y., Yoo, K.-H., and Yzombard, P.

Published
2024
Full Text
View/download PDF

44. Human and livestock surveillance revealed the circulation of Rift Valley Fever Virus in Agnam, Northern Senegal, 2021

Author

Mhamadi, Moufid, Badji, Aminata, Barry, Mamadou Aliou, Ndiaye, El Hadji, Gaye, Alioune, Ndiaye, Mignane, Mhamadi, Moundhir, Toure, Cheikh Talibouya, Ndiaye, Oumar, Faye, Babacar, Diop, Boly, Ndiaye, Mamadou, Fall, Mathioro, Diouf, Andy Mahine, Sagne, Samba Niang, Loucoubar, Cheikh, Fausther-Bovendo, Hugues, Sall, Amadou Alpha, Kobinger, Gary, Faye, Ousmane, Diallo, Mawlouth, and Faye, Oumar

Published
2023

45. Production of antihydrogen atoms by 6 keV antiprotons through a positronium cloud

Author

Adrich, P., Blumer, P., Caratsch, G., Chung, M., Cladé, P., Comini, P., Crivelli, P., Dalkarov, O., Debu, P., Douillet, A., Drapier, D., Froelich, P., Garroum, N., Guellati-Khelifa, S., Guyomard, J., Hervieux, P-A., Hilico, L., Indelicato, P., Jonsell, S., Karr, J-P., Kim, B., Kim, S., Kim, E-S., Ko, Y. J., Kosinski, T., Kuroda, N., Latacz, B. M., Lee, B., Lee, H., Lee, J., Lim, E., Liszkay, L., Lunney, D., Manfredi, G., Mansoulié, B., Matusiak, M., Nesvizhevsky, V., Nez, F., Niang, S., Ohayon, B., Park, K., Paul, N., Pérez, P., Regenfus, C., Reynaud, S., Roumegou, C., Roussé, J-Y., Sacquin, Y., Sadowski, G., Sarkisyan, J., Sato, M., Schmidt-Kaler, F., Staszczak, M., Szymczyk, K., Tanaka, T. A., Tuchming, B., Vallage, B., Voronin, A., van der Werf, D. P., Won, D., Wronka, S., Yamazaki, Y., Yoo, K-H., and Yzombard, P.

Subjects
High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

We report on the first production of an antihydrogen beam by charge exchange of 6.1 keV antiprotons with a cloud of positronium in the GBAR experiment at CERN. The antiproton beam was delivered by the AD/ELENA facility. The positronium target was produced from a positron beam itself obtained from an electron linear accelerator. We observe an excess over background indicating antihydrogen production with a significance of 3-4 standard deviations.

Published
2023
Full Text
View/download PDF

46. Analyse rétrospective intégrée du risque de dissémination de la flambée épizootique d'influenza aviaire hautement pathogène de 2021 à Grand-Bassam : Défis d’une gestion territorialisée en Côte d'Ivoire

Author

Ibrahima Mamby Keita, Rosalie Martine Ndew Seck, Christophe Yao Kouakou, Douyeri Thierry Ouattara, Catherine Linard, Aminata Diène Niang, Nicolas Antoine-Moussiaux, Bassirou Bonfoh, Isaac Tiembre, and Vessaly Kallo

Subjects
Volaillle, grippe aviaire, système de surveillance, gouvernance, territoire, Côte d'Ivoire, Animal culture, SF1-1100
Published
2025
Full Text
View/download PDF

47. Case report: Kinetics of viral load, immunoglobulins, and cytokines in a fatal case of Crimean-Congo hemorrhagic fever virus

Author

Moufid Mhamadi, Ousseynou Sene, Arfang Diamanka, Moundhir Mhamadi, Marie Pedapa Mendy, Andy Mahine Diouf, Mignane Ndiaye, Mamadou Aliou Barry, Samba Niang Sagne, Mahfouz Cissé Traoré, Amadou Alpha Sall, Gamou Fall, Ndongo Dia, and Oumar Faye

Subjects
CCHFV, biomarkers, viremia, immunoglobulins, cytokines, severity, Microbiology, QR1-502
Abstract

A fatal case of Crimean-Congo hemorrhagic fever virus (CCHFV) was detected in Dakar, Senegal, West Africa, in April 2023. To elucidate the mechanisms involved in this outcome, the kinetics of viral load, immunoglobulins, and cytokines were assessed using RT-qPCR and ELISA. A high IL-6 titer, low IL-10 titer, and delayed IgG response were associated with disease severity. These biomarkers may serve as predictors of disease severity, potentially aiding in early intervention and treatment strategies.

Published
2025
Full Text
View/download PDF

48. Situational analysis of malaria in Cabo Verde: From endemic control to elimination, history, cases data and challenges ahead.

Author

Adilson José DePina, Jonas António Lopes Gomes, António Lima Moreira, and El Hadji Amadou Niang

Subjects
Public aspects of medicine, RA1-1270
Abstract

On 12 January 2024, Cabo Verde was officially certified by the WHO as a malaria-free country after six consecutive years without local transmission. This study analysed the malaria history of Cabo Verde from 1953 to certification in 2024, highlighted the valuable lessons learned, and discussed challenges for prevention reintroduction. Malaria data from the last 35 years (1988-2022) were analysed using descriptive analyses, and cases were mapped using the USGS National Map Viewer. From 1988 to 2022, 3,089 malaria cases were reported, 2.381 (77.1%) locally and 708 (22.9%) imported. Imported cases were reported nationwide except on Brava Island. Six municipalities did not report any cases, while local cases were restricted to Santiago and Boavista, with 2.360 and 21 cases, respectively. Malaria history in the country revealed six remarkable steps and three periods of interruption in the transmission of local malaria cases. The last local cases were reported in Boavista in 2015 and Santiago in 2017. Since 2018, introduced cases have been recorded from time to time. Disease lethality was low, with ten malaria deaths from 2010 to 2023, and the highest value of 8.3% (3/36) recorded in 2011. With this certification, Cabo Verde became a reference in Africa for its health sector organisation, multisectoral, and partnership in malaria control. However, maintaining the certification presents several sustainability challenges for the country. Additionally, robust epidemiological and entomological surveillance, continued investigations, and ongoing research are crucial.

Published
2025
Full Text
View/download PDF

49. Characterization of food waste in Grizzly Dining Hall at Georgia Gwinnett College: A critical step toward sustainable food waste management

Author

Ramata Sissoko Cisse, Fatima Sarahi Aguilar, Sochi Bryan Ezenagu, Mahamane Saliou Cisse, and Amadou Niang

Subjects
Waste characterization, Waste generation rate, Solid waste management, Post-service waste, Campus waste, Science (General), Q1-390, Social sciences (General), H1-99
Abstract

This project investigated the generation and characterization of post-service food waste at Georgia Gwinnett College dining hall from Spring 2022 to Spring 2023. In Spring 2022, for three weeks, twice a week, a total of 115.08 kg of post-service food waste was collected by cafeteria workers. In Fall 2022, for 1 h, twice a week, for five weeks, post-service food waste was collected directly from visitors, sorted, and immediately weighed. During the first half of the Fall 2022 collection, 58.17 kg of food waste was collected and sorted into three categories, consisting of 17.90 % disposable cutlery, 20.46 % fruits and vegetables, and 61.64 % mixed food. During the second half of the Fall 2022 collection, 69.13 kg of food waste collected was composed of 12.84 % disposable cutlery, 23.59 % fruits and vegetables, and the mixed food subcategorized was composed of 11.27 % starch, 39.45 % grain, and 12.84 % meat and eggs. Finally, in Spring 2023, for six consecutive days, the waste was collected as previously but during the entire day and sorted. The average daily waste amounted to 113.41 kg, consisting of 18.20 % disposable cutlery, 16.62 % fruits and vegetables, 9.47 % starch, 33.26 % grain, and 22.45 % meat and eggs. Out of the food categories collected, grains constitute the largest source of food waste by weight. The study indicated that, on average, 140 g of food waste was produced per student per day during Spring 2023. The result of this study represents an opportunity for the college to identify the types and amounts of food waste generated at the cafeteria and to plan a better waste management system.

Published
2025
Full Text
View/download PDF

50. Crimean-Congo hemorrhagic fever virus survey in humans, ticks, and livestock in Agnam (Northeastern Senegal) from February 2021 to March 2022

Author

Mhamadi, Moufid, Badji, Aminata, Dieng, Idrissa, Gaye, Alioune, Ndiaye, El Hadji, Ndiaye, Mignane, Mhamadi, Moundhir, Toure, Cheikh Talibouya, Mbaye, Mouhamed Rassoul, Barry, Mamadou Aliou, Ndiaye, Oumar, Faye, Babacar, Ba, Fatimata Amadou, Diop, Boly, Ndiaye, Mamadou, Fall, Mathioro, Sagne, Samba Niang, Fall, Gamou, Loucoubar, Cheikh, Fausther-Bovendo, Hugues, Sall, Amadou Alpha, Kobinger, Gary, Faye, Ousmane, Diallo, Mawlouth, and Faye, Oumar

Published
2022

Catalog

Books, media, physical & digital resources
See catalog results