The Duffin-Kemmer-Petiau (DKP) equation is a relativistic wave equation governing the dynamics of spin-0 and spin-1 bosonic particles. In this work, we study the (1+3) -dimensional DKP equation with a spatially dependent mass under a modified deformed exponential type potential. Using the framework of supersymmetric quantum mechanics, we derive approximate analytical solutions. A novel extension of the Pekeris approximation is introduced to treat the centrifugal barrier, enabling the complete determination of the energy spectrum. The non-relativistic limit of the DKP equation is obtained via an established transformation technique. The model is applied to diatomic molecules including lithium hydride (LiH), hydrogen chloride (HCl), ^7Li_2 , Na_2 , and ScI. The energy spectra are computed for various quantum states | n,l,j⟩ using both relativistic and non-relativistic expressions. For LiH and HCl, where experimental data are scarce, our results show strong agreement with earlier theoretical predictions. For ^7Li_2 , Na_2 , and ScI, the calculated energies align excellently with available experimental data. The proposed framework provides a reliable and analytically tractable tool for studying bosonic systems with position-dependent effective masses.
This paper aims to investigate the effect of a noisy electric field on dynamic parameters of polaron in two-dimensional (2D) transition metal dichalcogenides (TMDs). We employ a theoretical framework based on the variational Lee-Low-Pines (LLP) method combined with a stochastic analysis of the noisy electric field. The dynamics are modeled by considering both longitudinal optical (LO) phonon of the crystal and surface optical (SO) induced by the polar substrates phonon interacting with electron and hole. The study reveals that noise significantly modifies the properties of the polaron: it increases their energies, reduces their lifetime and influences their mobility. The results also demonstrate that the studied 2D TMDs exhibit instantaneous negative values of the bandgap. However, this gap fluctuation, or transient closure, constitutes a dynamic instability induced by the correlated Ornstein–Uhlenbeck (OU) noise, rather than a structural or electronic phase transition in the thermodynamic sense of the term. We observe a highest mobility of polaronic entities in WS2. The present study provides deep insight into the role of the environment of the dielectric on dynamics parameters of 2D materials, highlighting the influence of noisy electric field on their physical properties.
BackgroundBreast and cervical cancers are among the most frequent malignancies in women worldwide and represent a growing public health concern in sub-Saharan Africa (SSA). In Gabon, national screening programs have been established, but their effectiveness remains poorly documented, particularly outside the capital city, Libreville. This study, therefore, aimed to describe the screening outcomes and associated factors for breast abnormalities and suspected cervical lesions at the Centre Hospitalier Universitaire Amissa Bongo (CHUAB) in Franceville, Gabon.MethodsWe conducted a retrospective cross-sectional study that included all women who attended routine screening at CHUAB between 2015 and, 2016 and, 2018 and 2021. Data were retrieved from hospital registries and medical records. All women underwent both clinical breast examination (CBE) and visual inspection with acetic acid (VIA). Sociodemographic, reproductive, and clinical variables were analyzed to determine their associations with screening outcomes using univariable and exploratory multivariable logistic regression models.ResultsA total of 1,328 women were included in the study, with a mean age of 35.4 ± 10.8 years. In univariable analysis, women aged 45–73 years had lower odds of cervical screening positivity compared with those aged 14–25 years (OR = 0.52, 95% CI: 0.29–0.90; p = 0.021). In exploratory multivariable analysis, non-Gabonese nationality and employment in the public sector were associated with cervical screening positivity. Regarding breast abnormalities, an age at first pregnancy between 30 and 39 years was associated with higher odds of screening positivity in univariable analysis (OR = 3.90, 95% CI: 1.07–11.4; p = 0.021); however, no factors remained statistically significant in the adjusted model.ConclusionThis study offers one of the first accounts of routine breast and cervical cancer screening outcomes in a semi-urban setting in south-eastern Gabon. VIA and CBE detected a measurable proportion of women with suspected cervical lesions and breast abnormalities, underscoring the value of these simple and accessible screening approaches in resource-limited settings. Strengthening follow-up systems, improving data management, and expanding screening coverage could further enhance cancer control among women in Gabon.
La mangrove sénégalaise, en grande partie couverte par dix-sept ires marines protégées, fait face à des pressions qu’il convient de cerner pour adapter sa conservation. Dans ce contexte, cette étude a été menée à l’Aire Marine Protégée de Joal-Fadiouth (AMPJF). La télédétection optique a été mobilisée dans la dynamique de la mangrove. Parallèlement, des enquêtes ont permis d’identifier les menaces halieutiques de la mangrove. Combinées à l’observation directe, ces enquêtes ont révélé d’autres pressions. La classification supervisée par le maximum de vraisemblance a distingué cinq classes dont la mangrove qui a perdu 0,137 km2 entre 1974 et 2024(de 10,259 km2 à 10,122 km2 ). Des techniques d’exploitations halieutiques, pratiquées dans la lagune durant l’intervalle étudié, sont considérées destructrices. Le cas pour 41,32% des acteurs affirmant que l’exploitation de poissons était menée en zone de mangroves avant la création de l’aire protégée et la totalité des acteurs pour l’exploitation d’huîtres avant, contre 3,69% après création de l’AMPJF. La coupe des palétuviers pour la récolte d’huîtres et l’usage des filets maillants pour les poissons ont contribué à dégrader la mangrove. D'autres facteurs de menaces relevées ont impliqué l’aménagement du pont ‘‘Mama Guedj’’, la salinisation, la pollution plastique et pétrolière. Parmi les mesures de gestion durable proposées par les parties prenantes sont notés le développement de la pisciculture et le renforcement des activités de reboisement, d’ostréiculture, de nettoyage de la lagune et de sensibilisation. Il est ressorti pertinent de mener une analyse intégrée des menaces naturelles et anthropiques afin de mettre en œuvre des stratégies durables et adaptées de gestion pour la mangrove de l’AMPJF. English title: Spatio-temporal dynamics of Joal-Fadiouth Marine Protected Area (JFMPA) mangrove, Senegal from 1974 to 2024 Senegal’s mangrove forests, largely covered by seventeen marine protected areas, face pressures that must be identified to adapt their conservation. In this context, this study was conducted in the Joal-Fadiouth Marine Protected Area (JFMPA). Optical remote sensing was used to study mangrove dynamics. At the same time, surveys identified threats to the mangrove from fishing exploitation. Combined with direct observation, these surveys revealed additional pressures. Maximum likelihood supervised classification identified five classes,including the mangrove, which lost 0.137 km² between 1974 and 2024 (from 10.259 km² to 10.122 km²). Fishing practices carried out in the lagoon during the study period are considered destructive. This was the case for 41.32% of stakeholders who stated that fish exploitation was conducted in mangrove areas before the protected area was established, and for all stakeholders regarding oyster exploitation before establishment, compared to 3.69% after the establishment of the JFMPA. The cutting of mangroves to harvest oysters and the use of gillnets to catch fish have contributed to mangrove degradation. Other threat factors included the construction of the “Mama Guedj” bridge, salinization, plastic and oil pollution. Among the sustainable management measures proposed by stakeholders are listed the development of fish farming and the strengthening of reforestation, oyster farming, lagoon clean-up and awareness-raising activities. It was deemed relevant to conduct an integrated analysis of natural and anthropogenic threats in order to implement sustainable and adapted management strategies for the JFMPA mangrove.
ABSTRACT Sub-Saharan Africa is an endemic region for human T-lymphotropic virus type 1 (HTLV-1). While high prevalence rates have been reported across Gabon, systematic screening of blood donors has not yet been implemented at the national level. A cross-sectional study was conducted on 2,375 blood donations from 2,303 blood donors at the Amissa Bongo Teaching Hospital Center in Franceville. Serological screening was performed via ELISA, followed by Western Blot confirmation and PCR-based proviral DNA amplification of the env gene. The overall HTLV-1 seroprevalence was 2.1% (95% CI: 1.6%–2.7%) at the donation level and 1.8% (95% CI: 1.3%–2.5%) at the donor level. The seroprevalence in Franceville was significantly higher than at the national blood bank in Libreville (ORa = 2.52; 95% CI: 1.5–4.2). History of blood transfusion was the only risk factor significantly associated with HTLV-1 infection (OR = 3.73; 95% CI: 1.3–9). Molecular analysis revealed a predominance of the HTLV-1b subtype (32/33), alongside one HTLV-1d strain, a subtype primarily reported in non-human primates. The high HTLV-1 seroprevalence among blood donors in southeastern Gabon, combined with the identification of a history of transfusion as a significant risk factor, represents a major challenge for transfusion safety in a semi-rural area. These results underscore the urgent need to integrate systematic HTLV-1 screening into the transfusion safety algorithm in Gabon to interrupt the cycle of iatrogenic transmission.IMPORTANCEHuman T-lymphotropic virus type 1 (HTLV-1) remains a major public health problem in Central Africa, with Gabon being a major endemic hotspot. This study addresses a critical issue for blood safety in semi-rural areas, where prevalence in the general adult rural population is exceptionally high, ranging from 7.3% to 8.7% according to previous studies. Here, we report a prevalence of 1.8% among blood donors in southeastern Gabon, a rate 2.5 times higher than that of blood donors in the capital. Moreover, a history of transfusion was identified as the only significant risk factor associated with HTLV-1 infection, directly demonstrating active iatrogenic transmission in the absence of systematic screening. Furthermore, the discovery of the rare HTLV-1d subtype highlights the persistent potential risk of zoonotic and human-to-human transmission in these forest-adjacent ecosystems. These results provide compelling evidence for the urgent integration of HTLV-1 screening in endemic rural areas of Gabon.
