Variations topographiques de la fructification d’une espèce ligneuse fourragère, Acacia tortilis (Forsk.) au Ferlo, Nord-Sénégal

La production annuelle de gousses de Acacia tortilis, a été suivie sur une toposéquence de 1,8% de dénivellation dans la réserve sylvo-pastorale de Sogobé au Nord-Sénégal. Les observations sont effectuées tous les quinze jours en saison des pluies et une fois par mois en saison sèche. Les suivis simultanés de la fructification de cette espèce en rapport avec l’évolution de l’eau du sol et des variables climatiques vise à caractériser l’effet de la topographie sur la production de gousses par unité de croissance. Les données sont soumises à une analyse multidimensionnelle et à une analyse de variance. La fructification de l’espèce intervient de novembre à juin. L’ACP effectuée à partir des relevés mensuels et des stades de fructification a permis d’identifier trois variables de la fructification : la nouaison des gousses, leur croissance et leur maturité et enfin leur dissémination. Cette dissémination peut être partielle (février et avril) ou totale (avril et juin). La nouaison des gousses concerne les mois de novembre et décembre (saison post-pluvieuse) alors que leur croissance et leur maturité se font de novembre à février (saison sèche fraîche). La dissémination des gousses de cette espèce et leur exploitation pour l’alimentation du bétail seraient à l’origine de la réduction de la densitédes fruits entre janvier et mai qui coïncide avec l’absence du tapis herbacée. Cependant, la biomasse des gousses par unité de croissance est significativement plus élevée chez les arbres de bas-fond qui bénéficient d’une alimentation hydrique plus favorable.Mots clés: Variabilité topographique, production de gousses, fourrage, Acacia tortilis, sahel, Zone sylvopastorale, Nord-Sénégal

Lamb-peak spectrum of the HD (2-0) P(1) line

A saturation spectroscopy measurement of the P(1) line of the ($2-0$) band in HD is performed in a sensitive cavity-enhanced optical setup involving frequency comb calibration. The spectral signature is that of a Lamb-peak, in agreement with a density-matrix model description involving 9 hyperfine components and 16 crossover resonances of $\Lambda$-type. Comparison of the experimental spectra with the simulations yields a rovibrational transition frequency at 209,784,242,007 (20) kHz. Agreement is found with a first principles calculation in the framework of non-adiabatic quantum electrodynamics within 2$\sigma$, where the combined uncertainty is fully determined by theory

Acute complications of preeclampsia: prognosis and management at Pikine National Hospital in Dakar (Senegal)

ABSTRACTBackground: The objective of this study was to evaluate the prevalence of acute complications of preeclampsia in order to describe the epidemiological profile of the disease, to assess its prognosis and management.Methods: This was a retrospective study of patients admitted to the Pikine National Hospital from 1 January 2010 to 31 December 2013 (48 months) with severe complicated pre-eclampsia. Included in this study were patients admitted or diagnosed with severe complicated pre-eclampsia and having given birth in the structure or not.Results: The incidence of severe preeclampsia in childbirth varied from 9.7% to 11.5% during the four years of our study. Patients were largely paucigest (55.7% of cases) and paucipares (58.5% of cases). The mean age was 28.14 years with extremes of 14 and 47 years. More than half of the patients (57.7%) were between 21 and 34 years of age. They were mostly married (90.7%). Three-quarters of the patients (76.8%) had proteinuria with ≥ 3 cross-bands. Thrombocytopenia was found in 9.7% of patients, hepatic cytolysis in 12.1%, and elevation of serum creatinine in 13.8%. The level of transaminases was found to be greater than 2 in the normal range in 12.1%. Complicated forms were the most represented in our study. These were acute complications, with 715 cases, or 57.3% of the patients. They were either isolated (52.8%) or associated (4.5%). These included eclampsia (24.9%), followed by retroplacental hematoma (24.6%), fetal death in utero (23.7%), HELLP syndrome (3.4%). , Acute edema of the lungs (1.5%), and acute renal failure (1.4%). The lethality was 2.4%. The causes of maternal death were dominated by eclampsia (14 cases), DIC (3 cases) and OAP (2 cases). We counted 77.7% of live births and a stillbirth of 254.5 ‰.Conclusions: Pre-eclampsia is a serious complication of pregnancy. Its frequency is still high in sub-Saharan Africa. In the presence of signs of severity, maternal (vital and functional) and neonatal prognosis are inevitably involved. If management is based on fetal extraction, resuscitation measures are a guarantee of maternal survival

Precision measurement of the fundamental vibrational frequencies of tritium-bearing hydrogen molecules: T2_2, DT, HT

High-resolution coherent Raman spectroscopic measurements of all three tritium-containing molecular hydrogen isotopologues T$_2$, DT and HT were performed to determine the ground electronic state fundamental Q-branch ($v=0 \rightarrow 1, \Delta J = 0$) transition frequencies at accuracies of $0.0005$ cm$^{-1}$. An over hundred-fold improvement in accuracy over previous experiments allows the comparison with the latest ab initio calculations in the framework of Non-Adiabatic Perturbation Theory including nonrelativisitic, relativisitic and QED contributions. Excellent agreement is found between experiment and theory, thus providing a verification of the validity of the NAPT-framework for these tritiated species. While the transition frequencies were corrected for ac-Stark shifts, the contributions of non-resonant background as well as quantum interference effects between resonant features in the nonlinear spectroscopy were quantitatively investigated, also leading to corrections to the transition frequencies. Methods of saturated CARS with the observation of Lamb dips, as well as the use of continuous-wave radiation for the Stokes frequency were explored, that might pave the way for future higher-accuracy CARS measurements.Comment: 15 pages, 13 figure

Hyperfine-Resolved Near-Infrared Spectra of H2_{2}17^{17}O

Huge efforts have recently been taken in the derivation of accurate compilations of rovibrational energies of water, one of the most important reference systems in spectroscopy. Such precision is desirable for all water isotopologues, although their investigation is challenged by hyperfine effects in their spectra. Frequency-comb locked noise-immune cavity-enhanced optical-heterodyne molecular spectroscopy (NICE-OHMS) allows for achieving high sensitivity, resolution, and accuracy. This technique has been employed to resolve the subtle hyperfine splittings of rovibrational transitions of H$_{2}$$^{17}$Oin the near-infrared region. Simulation and interpretation of the H$_{2}$$^{17}$Osaturation spectra have been supported by coupled-cluster calculations performed with large basis sets and accounting for high-level corrections. Experimental $^{17}$O hyperfine parameters are found in excellent agreement with the corresponding computed values. The need of including small hyperfine effects in the analysis of H$_{2}$$^{17}$O spectra has been demonstrated together with the ability of the computational strategy employed for providing quantitative predictions of the corresponding parameters

A hybrid optical-wireless network for decimetre-level terrestrial positioning

Global navigation satellite systems (GNSS) are widely used for navigation and time distribution, features indispensable for critical infrastructure such as mobile communication networks, as well as emerging technologies like automated driving and sustainable energy grids. While GNSS can provide centimetre-level precision, GNSS receivers are prone to many-metre errors due to multipath propagation and obstructed view of the sky, which occur especially in urban areas where accurate positioning is needed most. Moreover, the vulnerabilities of GNSS, combined with the lack of a back-up system, pose a severe risk to GNSS-dependent technologies. Here, we demonstrate a terrestrial positioning system which is independent of GNSS and offers superior performance through a constellation of radio transmitters, connected and time-synchronised at the sub-nanosecond level through a fibre-optic Ethernet network. Employing optical and wireless transmission schemes similar to those encountered in mobile communication networks, and exploiting spectrally efficient virtual wideband signals, the detrimental effects of multipath propagation are mitigated, thus enabling robust decimetre-level positioning and sub-nanosecond timing in a multipath-prone outdoor environment. This work provides a glimpse of a future in which telecommunication networks provide not only connectivity, but also GNSS-independent timing and positioning services with unprecedented accuracy and reliability.Comment: 38 pages, 9 figures, 3 table

Osteolipoma: An unusual tumor of the parotid region

SummaryPurpose of studyOncology of the parotid region is rich and varied, like its components. During his career, the ENT surgeon may come across such an exceptional tumor as osteolipoma. The aim of this study was to describe the rarity and the etiopathogeny of osteolipoma with parapharyngeal location.Patients and methodWe had the opportunity to find this uncommon tumor in a 21-year-old female patient. The mass located in the parotid region was hard, barely mobile and at first looked like a parotid tumor. Total parotidectomy with facial nerve preservation was performed. It revealed a stony and dented tumor inside the internal lobe of the parotid located in the parapharyngeal space between the vertical portion of the mandible anteriorly and the styloid apophyse posteriorly. Macroscopic examination of the piece evidenced a lipomatous mass with hard as bone nodes in its middle. Histology revealed an osteolipoma.ConclusionA review of the literature shows the uncommon occurrence of this type of tumor. A few rare cases were reported among which two involving the parapharyngeal space

Rodents as natural hosts of zoonotic Schistosoma species and hybrids: an epidemiological and evolutionary perspective from West Africa

The complex multi-host disease dynamics of schistosomiasis and Schistosoma spp., including the emergence of zoonotic parasite hybrids, remain largely unexplored in West Africa. We elucidated the role of wild small mammals as reservoir for zoonotic Schistosoma species and hybrids in endemic areas of Senegal. We identified Schistosoma mansoni, Schistosoma bovis, and a Schistosoma haematobium/S. bovis hybrid, with local prevalence in wild rodents ranging from 1.9% to 28.6%. Our findings indicate that rodents may be an important local reservoir for zoonotic schistosomiasis in endemic areas of West Africa, amplifying transmission to humans and acting as natural definitive hosts of schistosome hybrids

Présence de métaux lourds et de résidus médicamenteux dans les effluents des établissements de santé de Dakar (Sénégal)

L’objectif de cette étude est de quantifier les concentrations en métaux lourds et de rechercher la présence de résidus de molécules médicamenteuses des effluents de trois hôpitaux de Dakar (Sénégal). C’est ainsi que la collecte des effluents a été réalisée chaque jour sur une période de trois semaines à l’entrée du déversoir des services de radiologie, de médecine interne et d’odontologie. Ensuite, des échantillons composites par semaine ont été constitués pour rechercher leur composition en métaux lourds et en résidus médicamenteux. Le transport a été effectué à +4 °C et à l'obscurité pour assurer une conservation satisfaisante. Les métaux lourds ont été dosés par ICP-MS et les résidus de médicaments ont été recherchés par UPLCMS/ MS. Les médicaments identifiés dans les effluents sont essentiellement des analgésiques et des psychotropes. La concentration en métaux lourds des effluents des trois hôpitaux est inférieure aux normes sénégalaises et de celles de L’OMS fixant les conditions de rejet de métaux dans les eaux usées. Cependant, bien que les taux retrouvés soient tolérables, leur introduction continuelle en milieu aquatique pourrait être à l’origine d’effets néfastes sur les organismes marins par des phénomènes de bioaccumulation et de biomagnification. D’où l’importance et la nécessité des stations d’épuration pour une bonne gestion et une réduction des risques écotoxicologiques liés aux effluents liquides hospitaliers.Mots clés : Effluents hospitaliers, métaux lourds, résidus médicamenteux, toxicité