The protection of database systems content using digital watermarking is nowadays an emerging research direction in information security. In the literature, many solutions have been proposed either ...for copyright protection and ownership proofing or integrity checking and tamper localization. Nevertheless, most of them are distortion embedding based as they introduce permanent errors into the cover data during the encoding process, which inevitably affect data quality and usability. Since such distortions are not tolerated in many applications, including banking, medical, and military data, reversible watermarking, primarily designed for multimedia content, has been extended to relational databases. In this article, we propose a novel prediction-error expansion based on reversible watermarking strategy, which not only detects and localizes malicious modifications but also recovers back the original data at watermark detection. The effectiveness of the proposed method is proved through rigorous theoretical analysis and detailed experiments.
Immune activation has been suggested to increase susceptibility to human immunodeficiency virus type 1 (HIV-1) transmission, while at the same time it could be deemed essential for mounting an ...effective antiviral immune response. In this study, we compared levels of T cell activation between exposed seronegative (ESN) partners in HIV-1 discordant couples and HIV-unexposed control subjects in Dakar, Senegal. ESN subjects showed lower levels of CD38 expression on CD4+ T cells than did control subjects. However, this was found to be associated with concurrent differences in the use of condoms: ESN subjects reported a higher degree of condom use than did control subjects, which correlated inversely with CD38 expression. In addition, we observed markedly higher levels of T cell activation in women compared with men, irrespective of sexual behavior. These findings question the relevance of low-level CD4+ T cell activation in resistance to HIV-1 infection and underscore the need to take gender and sexual behavior characteristics of high-risk populations into account when analyzing correlates of protective immunity.
Managing neurocysticercosis: challenges and solutions Fogang, Yannick Fogoum; Savadogo, Abdoul Aziz; Camara, Massaman ...
International Journal of General Medicine,
01/2015, Letnik:
8, Številka:
default
Journal Article, Book Review
Recenzirano
Odprti dostop
Taenia solium neurocysticercosis (NCC) is a major cause of neurological morbidity in the world. Variability in the neuropathology and clinical presentation of NCC often make it difficult to diagnose ...and manage. Diagnosis of NCC can be challenging especially in endemic and resource-limited countries where laboratory and imaging techniques are often lacking. NCC management can also be challenging as current treatment options are limited and involve symptomatic agents, antiparasitic agents, or surgery. Although antiparasitic treatment probably reduces the number of active lesions and long-term seizure frequency, its efficacy is limited and strategies to improve treatment regimens are warranted. Treatment decisions should be individualized in relation to the type of NCC. Initial measures should focus on symptomatic management, with antiparasitic therapy only to be considered later on, when appropriate. Symptomatic treatment remains the cornerstone in NCC management which should not only focuses on epilepsy, but also on other manifestations that cause considerable burden (recurrent headaches, cognitive decline). Accurate patients' categorization, better antiparasitic regimens, and definition of new clinical outcomes for trials on NCC could improve management quality and prognosis of NCC. Prevention strategies targeting tapeworm carriers and infected pigs are yielding good results in local models. If local elimination of transmission is confirmed and replicated, this will open the door to cysticercosis eradication efforts worldwide.
Laboratory follow-up of HIV patients in resource-limited settings requires appropriate instruments for CD4 T cell enumeration. In this study, we evaluated the application of a simplified, mobile and ...robust flow cytometry system, the Apogee Auto 40 analyzer (Auto40) using thermoresistant reagents, for CD4 T cell enumeration. We measured the absolute CD4 counts in fresh whole blood samples from 170 Senegalese subjects, including 129 HIV-positive (HIV+) patients and 41 HIV-negative (HIV−) controls. Based on volumetric primary CD4 gating, cells were stained with commercially available reagents (Easy MoAb CD4;Bio-D, Valenzano, Italy) and analyzed on the Auto40. The results were compared with those from the FACSCount system (Becton Dickinson, San Jose, USA). Repeatability analysis was performed on duplicate testing of 49 samples on both FACSCount and Auto40. The intra-run precision was measured by 10 replicates using 3 clinical blood samples with low, intermediate and high CD4 concentrations.
The results from the two instruments were in good agreement. The percent similarity between the results of both instruments was 99%
±
relative standard deviation of 12.7%. The concordance correlation coefficient was 0.99. The absolute bias and limits of agreement (LOA) between the two instruments, calculated by Bland–Altman analysis, were clinically acceptable (bias: +
4 cells/μl; LOA: −111 to +
120 cells/μl). The clinical agreement between the two instruments at a cutoff of 200 CD4 cells/μl was 94%. The repeatability of measurements on the Auto40 was also similar to that observed with FACSCount system (bias +
0.1 cells/μl, coefficient of variation 2.5%
vs bias −
1.1
cells/μl, coefficient of variation 2.9% respectively). In conclusion, our results indicate that the Auto 40 system, using thermoresistant reagents, is suitable for CD4 T cell enumeration and will be a helpful tool to improve HIV laboratory monitoring in resource-limited settings.
► In this study we evaluate a volumetric flow Cytometer Auto40 for CD4 counts in HIV infection. ► This low-cost CD4+ T cell counting technology showed a good agreement, similarity, accuracy and precision. ► The use of thermoresistant reagents for CD4 counting is important advantage where cold chain is not guaranteed. ► This instrument will be a helpful to improve HIV laboratory monitoring in resource-limited settings.
Sahelian savannah faces increasing pressure from human activities, leading to its degradation. The aim of this study was to investigate the possibility of restoration of dryland savannah vegetation ...by the elimination of disturbance factors on the ecosystem. Is degraded dryland savannah vegetation able to be restored by means of natural succession? What is the timescale for its recovery? The study took place in the Bandia Reserve, 65 km south-east of Dakar (Senegal), a unique site with two successional stages due to the elimination of uncontrolled exploitation. The vegetation structure of 15 years (15YRS) and 5 years (5YRS) after fencing was compared with vegetation exposed to continuous livestock grazing and wood collection outside the fenced area. Calculated by redundancy analysis, a significant effect of selected areas on the cover of all species was revealed and successional stage explained more than 45% of data variability. Perennial forbs, annual forbs and perennial grasses achieved the highest cover in 5YRS, woody species in 15YRS and annual grasses in the area outside of the fenced reserve. The dominant woody species Acacia seyal, A. ataxacantha, A. nilotica subsp. adstringens and Balanites aegyptiaca reconstituted the dense formation of Acacia bushland by means of natural succession in the 15YRS area.
Flow cytometry is an accurate but expensive method to determine absolute CD4 cell counts. We compared different methods to measure absolute CD4 counts in blood samples from HIV-infected and ...uninfected subjects using a research/clinical flow cytometer (FACScan); a dedicated clinical instrument (FACSCount); and a volumetric, mobile, open-system flow cytometer equipped with 3 fluorescence and 2 light scatter detectors (Cyflow SL blue). The FACScan and Cyflow were used as single-platform instruments, but they differ in running cost, which is a central factor for resource-poor settings. Direct volumetric and bead-based CD4 measurements on the Cyflow were compared with 2 bead-based single-platform CD4 measurements on the FACSCount and on FACScan (TruCount) in “Le Dantec” Hospital, Dakar, Senegal, using whole blood samples from 102 HIV and 28 HIV subjects. The agreement between the various measurement methods was evaluated by Bland-Altman analysis. Volumetric CD4 measurements on the Cyflow using a no-lyse-no-wash (NLNW) procedure and a lyse-no-wash (LNW) procedure correlated well with each other (R = 0.98) and with CD4 measurements on the FACSCount (R = 0.97) and FACScan (R = 0.97), respectively. Red blood cell lysis had no negative effect on the accuracy of absolute CD4 counting on the Cyflow. An excellent correlation was observed between bead-based CD4 measurements on the Cyflow and CD4 measurements on the FACSCount (R = 0.99) and FACScan (R = 0.99). Rigid internal and external quality control monitoring and adequate training of technicians were considered essential to generate accurate volumetric CD4 measurements on the Cyflow.
Au Sénégal, la banane est essentiellement produite dans les zones Sud-Est cependant cette production ne couvre même pas la moitié des besoins de consommations du pays qui continue à dépendre des ...importations à cause entre autres de l’absence de maîtrise des facteurs de production. Cette étude a été réalisée dans le but de caractériser la structure de la flore adventice de la banane en Haute Casamance et au Sénégal oriental. Des relevés ont été effectués dans des parcelles suivant la méthode des diagonales dans des quadrats de 50 cm de côté. Les résultats montrent que la flore adventice dans les bananeraies est composée de 76 espèces appartenant 56 genres et 18 familles. Cette flore est constituée à 86% d’espèces annuelles contre 14% d’espèces à caractères pérennes. Les familles des Poaceae, des Fabaceae et des Malvaceae sont les mieux représentées et cumulent près de la moitié des espèces recensées. L’évaluation de la valeur écologique des espèces (IVI index) a ressorti que Commelina benghalensis, Cyperus rotundus, Euphorbia heterophylla sont les espèces les plus infestantes dans les plantations de bananeraies. En plus de leur nuisibilité directe, ces trois espèces, en compagnie du Croton hirtus sont reconnues comme étant des hôtes alternatifs de nombreux pathogènes notamment le virus de la mosaïque du concombre (CMV), le virus du PVMY et le virus du PVMV. Cependant, la majorité des espèces ont une fréquence et un recouvrement faibles même si certaines d’entre-elles comme Croton hirtus sont à surveiller afin de limiter leur expansion. En effet, elles sont envahissantes dans certaines zones et/ou culture et résiste à la plupart des herbicides de post-levés actuellement vulgarisés. Cette étude préliminaire des adventices de la banane au Sénégal est utile et nécessaire pour planifier des approches de lutte intégrée des adventices prenant en compte le travail du sol, l’utilisation des herbicides, la fertilisation et les variétés. Mots-clés: Bananeraie, Adventices, Recouvrement, IVI index, Sud-Est Sénégal
HIV is highly prevalent in men who have sex with men (MSM) in West Africa. Many MSM in the region also have sex with women (MSMW). Accordingly, they are a potential bridge subpopulation for HIV ...transmission to women. We aimed to evaluate the proportions and characteristics of West African MSMW at high behavioral risk of acquiring HIV from male partners and transmitting it to female partners (HBRMF). The cohort ANRS-12324 CohMSM Study included 630 HIV-negative MSM in Burkina Faso, Cote d’Ivoire, Mali, and Togo. Among MSMW (i.e., with ≥ 1 female partner) in the cohort, HBRMF was identified using trajectory models based on seven at-risk sexual practices with male and female partners, including inconsistent condom use, multiple partnerships, and receptive same-sex anal intercourse. To assess the relevance of using trajectory models, we compared the proportions of participants who seroconverted during the cohort follow-up among those at HBRMF and those not at HBRMF. Factors associated with HBRMF were identified using a generalized estimation equation logistic regression model accounting for longitudinal data. Approximately half (47%) of the 304 MSMW (22% of all CohMSM study participants) were at HBRMF. This group accounted for 75% of the 28 HIV seroconversions observed during follow-up (
p
= 0.001). HBRMF was positively associated with being aged < 25 years (aOR 95% CI 1.67 1.23–2.27), being sexually attracted only to men (1.97 1.38–2.78), feelings of loneliness (1.92 1.38–2.65), and homonegative violence score (1.22 1.05–1.41). HBRMF was negatively associated with having had both stable and casual female partners in the previous 6 months (0.34 0.20–0.60 vs. only a stable female partner). HBRMF tended to be negatively associated with having ≥ 4 sexual intercourses with female partners in the previous four weeks (0.54 0.27–1.06 vs. no intercourse). Establishing official relationships with women might be a strategy for young and/or stigmatized MSMW to comply with social pressure to display a heterosexual lifestyle. However, this seems to increase the risk of HIV transmission to female partners. In the present study, almost half of MSMW were at HBRMF. This result stresses the need to adapt HIV research and prevention to MSMW and their female partners.
Le Sénégal oriental est une région très riche de par sa flore, sa faune mais également de par son sous-sol qui renferme d’intéressants indices ou gisements d’or, d’uranium, de fer, de cuivre, de ...nickel, de lithium, de marbre, de molybdène et de chrome. Cette exploitation n’est toutefois pas sans conséquences car les activités extractives causent d’énormes préjudices notamment à l’environnement. La présente étude se fixe comme objectif d’établir la situation de référence de la flore ligneuse de la zone. Ainsi à partir d’un échantillonnage de type aléatoire stratifié et d’un maillage systématique, l’étude de la flore du site a été faite en utilisant la méthode de l’inventaire itinérant. La flore de la zone d’exploitation minière de la commune de Sabodala et ses environs est riche de 103 espèces distribuées dans 75 genres et 32 familles. Les Fabaceae, Combretaceae et Malvaceae sont les familles majoritaires de cette flore. Le genre Combretum est le plus riche avec 7 espèces. Le spectre biologique montre une prédominance des microphanérophytes et des mésophanérophytes. Les espèces de l’élément-base soudanien sont majoritaires avec 35,3 %, indiquant le caractère soudanien de la zone. Ces résultats sont très importants dans les processus de reconstitution de la flore de la zone. Mots-clés: flore ligneuse, Goumbati-Kobokoto, savanes, zone soudanienne
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