Combinatorial kk-systoles on a punctured torus and a pair of pants

In this paper, $S$ denotes a surface homeomorphic to a punctured torus or a pair of pants. Our interest is the study of \emph{\textbf{combinatorial $k$-systoles}} that is closed curves with self-intersection numbers greater than $k$ and with least combinatorial length. We show that the maximal intersection number $I^c_k$ of combinatorial $k$-systoles of $S$ grows like $k$ and $\underset{k\rightarrow+\infty}{\limsup}(I^c_k-k)=+\infty$. This result, in case of a pair of pants and a punctured torus, is a positive response to the combinatorial version of the Erlandsson - Parlier conjecture, originally formulated for the geometric length.Comment: 12 pages, 8 figure

AfriQA:Cross-lingual Open-Retrieval Question Answering for African Languages

African languages have far less in-language content available digitally, making it challenging for question answering systems to satisfy the information needs of users. Cross-lingual open-retrieval question answering (XOR QA) systems -- those that retrieve answer content from other languages while serving people in their native language -- offer a means of filling this gap. To this end, we create AfriQA, the first cross-lingual QA dataset with a focus on African languages. AfriQA includes 12,000+ XOR QA examples across 10 African languages. While previous datasets have focused primarily on languages where cross-lingual QA augments coverage from the target language, AfriQA focuses on languages where cross-lingual answer content is the only high-coverage source of answer content. Because of this, we argue that African languages are one of the most important and realistic use cases for XOR QA. Our experiments demonstrate the poor performance of automatic translation and multilingual retrieval methods. Overall, AfriQA proves challenging for state-of-the-art QA models. We hope that the dataset enables the development of more equitable QA technology

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

L'insertion urbaine : le cas de Dakar

Sur le programme de l'insertion urbaine à Dakar, ce volume rassemble différentes réflexions méthodologiques concernant l'élaboration d'une enquête, avec une place importante consacrée à l'aspect démographique et biographique. Les premiers résultats montrent l'importance des solidarités familiales qui permettent aux individus de résister à la crise. L'accueil des migrants est de plus en plus assuré par la parenté déjà installée en ville, avec pour conséquence une augmentation de la taille des ménages et une dépendance grandissante des plus jeunes envers les aîné

Refractory cervical dystonia, unresolve issue and therapeutic challenge: Follow-up of a case with surgical denervation combined with conservative treatments

Cervical dystonia is the most common focal dystonia affecting adults. It frequently causes postural control problems, neck pain and spasm attacks of the cervical musculature. One of the surgical options available is selective cervical denervation. We report the case of a 32-year-old patient with cervical dystonia refractory to conservative treatment and an injection of botulinum toxin A, which was finally completed by bilateral selective cervical denervation, with considerable regression of cervical spasm at 16 months post-operatively.The clinical presentation of cervical dystonia includes abnormal movements or postural changes of the head, neck and shoulders caused by involuntary contractions of the cervical muscles. When the spasmodic attacks are recurrent, they can cause real handicaps for the patient. The causes of the disease and its pathophysiological mechanism are still poorly understood. There are a number of treatment options, including pharmacological therapy and surgery in cases of therapeutic failure. Repeated intramuscular injections of botulinum toxin are the first-line treatment. Some conservative measures such as physiotherapy are also used, although there is little literature on these approaches.Selective peripheral denervation is currently the main surgical treatment for refractory cervical dystonia. A combination of conservative treatment with BT-A injection and denervation appears to be an effective treatment option

Les aspects des frottis cervico-vaginaux chez les femmes vivants avec le VIH suivies à Thiès/Sénégal et association avec le degré d’immunodépression

De nombreuses études ont démontré que les femmes infectées par le VIH ont un risque accru de survenue de néoplasies cervicales intra épithéliales. L'association entre les deux affections étant bidirectionnelle, l'objectif était de décrire les anomalies cervicales chez les femmes séropositives au virus de l'immunodéficience humaine (VIH), de rechercher des facteurs associés et de proposer des recommandations en termes de suivi de ces femmes. Il s'agissait d'une étude transversale, multicentrique recensant l'ensemble des frottis cervico-vaginaux (FCV) et des colposcopies des patientes infectées par le VIH entre 2012 et 2014 dans les services de dermatologie de Thiès et de Mbour. Les données étaient recueillies et analysées par le logiciel EPI Info 2012 version 3.5.4. Les tests statistiques ont été effectués avec un seuil de significativité p < 0,05. Etaient inclus 125 patientes. L'âge moyen était de 38,98 ± 10.2 ans [20-77]. Il n'y avait aucun signe d'appels dans 82.4%. Le FCV était normal dans 32.8%, inflammatoire dans 44.8%. Les anomalies cytologiques concernaient 22,4% dont, ASC-H (suspicion de lésions de haut grade: 2.4%), LSIL (lésions de bas grade: 8.8%), HSIL (lésions de haut grade: 4%). Leur majorité (60.7%) avaient un taux de CD4 < 500 et étaient au stade 3 de l'OMS dans 64.3%; la biopsie montrait une dysplasie sévère chez 37.5% des patientes ayant pu réaliser cet examen. Deux patientes ont bénéficié d'un traitement curatif notamment l'exérèse chirurgicale. La survenue de dysplasies cervicales même précoces semble être associée à un stade avancé de l'infection VIH. Un dépistage et un traitement précoces sont absolument nécessaires.The Pan African Medical Journal 2015;2

Distribution and breeding numbers of a recently split species, the West African Crested Tern Thalasseus albididorsalis

This study investigated the distribution, numbers and conservation threats of the West African Crested Tern, which was recently elevated to full species after it was split from the Royal Tern with an American and African subspecies. In the period 1998–2019, a total of 13 West African coastal islands were identified as breeding localities, stretching from Mauritania to Guinea. All the islands are isolated, usually sandy and subject to erosion. There was great yearly variation in the numbers of breeding pairs within and between sites. A complete census of all breeding locations in 2015 and 2019 resulted in estimates of 79 000 and 77 000 pairs, respectively. The threats identified are predation, human disturbance, nest flooding and loss of breeding habitat as a result of coastal erosion. Predation of eggs and chicks by Sacred Ibises and especially Great White Pelicans may heavily impact on the species’ breeding output. Human disturbance is slight because most of the breeding islands are within protected areas. Flooding of nests has increasingly been observed in recent years, occurring at nine of 11 islands occupied by the terns in 2015. Most islands are subject to erosion, which has resulted in substantial loss of suitable breeding habitat over the 22-year study period. Two important islands have become completely unsuitable. We conclude that West African Crested Terns have an uncertain future. Food shortage resulting from industrial fishing is suspected, and the effects of climate change might negatively impact on habitat suitability and food availability. Monitoring of the total population at three-year intervals is recommended

L'insertion urbaine : le cas de Dakar Annexe 1 : methodologie des enquetes - annexe 2 : tableaux de l'enquete menage

Available at INIST (FR), Document Supply Service, under shelf-number : AR 15382 (1); AR 15382 (2); AR 15382 (3) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc