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In many parts of the world, including Cameroon, mycotoxin contamination of groundnuts remains a major constraint affecting their use as food. Understanding the contributing factors is an essential intervention to reduce contamination and people’s exposure to these harmful toxins. The aim of this research was to identify the factors associated with the knowledge, perceptions, and postharvest practices of groundnut farmers in three production basins in Cameroon. Data were collected through surveys and analyzed using descriptive methods and logistic regression models. The results show that groundnut farmers are little aware of the existence of mycotoxins (12%) and totally unaware of the existence of aflatoxins (100%). Only 7.1% of these farmers are aware of the effects of mycotoxins on consumer health. After evaluation, the large majority of farmers scored poor marks for knowledge (86%) and practice (98.7%) in the management of mould and mycotoxins in groundnuts. Knowledge of mycotoxins was positively associated with the level of education [OR = 3.42; (95%-IC: 1.00–16.00); p

Aryl hydrocarbon receptor (AHR) is a sensor of the chemical environment including pollutants, diet components and metabolites. Here, authors determine the structure of the indirubin-bound AHR cytosolic complex providing mechanistic insights into ligand-binding promiscuity and selectivity.

One of the most fundamental discoveries in human biology was that of the existence of essential micronutrients that the body cannot synthesize but nonetheless requires for proper functioning [...]

This paper proposes a fairly general new point of view on the question of asymptotic stability of (topological) solitons. Our approach is based on the use of the distorted Fourier transform at the nonlinear level; it does not rely only on Strichartz or virial estimates and is therefore able to treat low-power nonlinearities (hence also nonlocalised solitons) and capture the global (in space and time) behaviour of solutions.

Les fractures du bassin surviennent le plus souvent au décours d´un traumatisme violent. Malgré ce contexte de haute vélocité, ces lésions sont rarement associées à des plaies du vagin et les données sur l´évolution sont rares. L´objectif de notre étude était de décrire les lésions anatomocliniques, le traitement et l´évolution de ces lésions. Nous avons observé cinq cas de plaies du vagin au cours d´une fracture du bassin chez la femme au cours de ces dix dernières années. Les patientes avaient un âge moyen de 23,6 ans. Le motif principal était les accidents de la voie publique. Deux patientes présentaient des plaies linéaires et trois présentaient des plaies délabrantes. Des sutures vaginales ont été réalisées chez toutes les patientes. Au recul moyen de deux ans, l´évolution a été favorable avec cicatrisation de la plaie vaginale et de l´os. Les activités génitales et obstétricales n´ont pas été compromises. Ce sont des lésions qui passent le plus souvent inaperçues. Il faudra y penser devant tout traumatisme du bassin chez la femme.

The three subtypes (α, β, and γ) of the retinoic acid receptor (RAR) are ligand-dependent transcription factors that mediate retinoic acid signaling by forming heterodimers with the retinoid X receptor (RXR). Heterodimers are functional units that bind ligands (retinoids), transcriptional co-regulators and DNA, to regulate gene networks controlling cell growth, differentiation, and death. Using biochemical, crystallographic, and cellular approaches, we have set out to explore the spectrum of possibilities to regulate RXR-RAR heterodimer-dependent transcription through various pharmacological classes of RAR- and RXR- specific ligands, alone or in combination. We reveal the molecular details by which these compounds direct specificity and functionality of RXR-RAR heterodimers. Among these ligands, we have reevaluated and improved the molecular and structural definition of compounds CD2665, Ro41-5253, LE135, or LG100754, highlighting novel functional features of these molecules. Our analysis reveals a model of RXR-RAR heterodimer action in which each subunit retains its intrinsic properties in terms of ligand and co-regulator binding. However, their interplay upon the combined action of RAR- and RXR-ligands allows for the fine tuning of heterodimer activity. It also stresses the importance of accurate ligand characterization to use synthetic selective retinoids appropriately and avoid data misinterpretations.

Les auteurs rapportent les complications survenues au cours de la prise en charge des fractures ouvertes de membres inférieurs, observées ces dernières années dans leur pratique et qui ont abouti à des amputations secondaires, tout en analysant les différents facteurs de risque et les déficits éventuels dans la prise en charge qui ont pu être à l'origine de cette évolution. Il s'agissait d'une étude rétrospective s'étendant sur une période de 06 ans ( Janvier 2006 - Janvier 2012). Elle concernait des patients ayant présenté une fracture ouverte de membre inférieur traité initialement dans notre institution et dont les suites se sont compliquées et ont nécessité une amputation. Tout patient dont l'amputation avait été réalisée d'emblée après l'examen à l'entrée aux urgences était exclu. Egalement tout patient traité dans un autre hôpital avant d'être admis chez nous était exclu de l'étude, même si une amputation secondaire avait été réalisée dans notre institution. Nous avons récolté les différentes données en analysant les dossiers de patients (examens cliniques et complémentaires, comptes rendus opératoires). Nous avons évalué notre prise en charge en fonction des différents guidelines et recommandations retrouvés dans la littérature. Ces complications ont été observées chez neuf patients sur les 306 fractures ouvertes de membre inférieur prises en charge sur la même période (Janvier 2006 - Janvier 2012), soit 2,9 . L'âge moyen était de 42,6(26-57) ans, la totalité des patients était de sexe masculin. Nous avons enregistré 1 cas de fracture du fémur, 7 cas de fracture des 2 os de la jambe et 1 cas d'écrasement du pied. Il s'agissait de fracture ouverte dont 1 cas de type 1; 3 cas de type II et 5 cas de type III selon la classification de Gustilo et Anderson. 5 cas d'amputations à la cuisse ont été réalisées et 4 cas d'amputation au tiers supérieur de la jambe. Les différentes complications ayant motivées ces amputations étaient des infections osseuses ou des gangrènes de parties molles d'origine ischémique ou infectieuse. Les patients n'avaient pas de tares favorisantes telle que le diabète et n'étaient pas tabagiques chroniques. Nous n'avons pas constaté de décès. Les fractures ouvertes méritent une attention particulière du chirurgien tant au point de vu diagnostic des complications immédiates que thérapeutique afin de réduire l'incidence des amputations post chirurgie primaire donnant l'impression au patient d'avoir été initialement mal opéré. Une attention particulière doit être portée au degré de contamination initiale et à la présence d'un germe virulent sur le lieu du traumatisme, pouvant motiver des attitudes particulières lors de la prise en charge primaire.

Retinoic acid is an important regulator of cell differentiation which plays major roles in embryonic development and tissue remodeling. The biological action of retinoic acid is mediated by three nuclear receptors denoted RARα, β and γ. Multiple studies support that RARβ possesses functional characteristics of a tumor suppressor and indeed, its expression is frequently lost in neoplastic tissues. However, it has been recently reported that RARβ could also play a role in mammary gland tumorigenesis, thus demonstrating the important but yet incompletely understood function of this receptor in cancer development. As a consequence, there is a great need for RARβ-selective agonists and antagonists as tools to facilitate the pharmacological analysis of this protein in vitro and in vivo as well as for potential therapeutic interventions. Here we provide experimental evidences that the novel synthetic retinoid BMS948 is an RARβ-selective ligand exhibiting a full transcriptional agonistic activity and activating RARβ as efficiently as the reference agonist TTNPB. In addition, we solved the crystal structures of the RARβ ligand-binding domain in complex with BMS948 and two related compounds, BMS641 and BMS411. These structures provided a rationale to explain how a single retinoid can be at the same time an RARα antagonist and an RARβ full agonist, and revealed the structural basis of partial agonism. Finally, in addition to revealing that a flip by 180° of the amide linker, that usually confers RARα selectivity, accounts for the RARβ selectivity of BMS948, the structural analysis uncovers guidelines for the rational design of RARβ-selective antagonists.

Understanding the role of gene duplications in establishing vertebrate innovations is one of the main challenges of Evo-Devo (evolution of development) studies. Data on evolutionary changes in gene expression (i.e., evolution of transcription factor-cis-regulatory elements relationships) tell only part of the story; protein function, best studied by biochemical and functional assays, can also change. In this study, we have investigated how gene duplication has affected both the expression and the ligand-binding specificity of retinoic acid receptors (RARs), which play a major role in chordate embryonic development. Mammals have three paralogous RAR genes--RAR alpha, beta, and gamma--which resulted from genome duplications at the origin of vertebrates. By using pharmacological ligands selective for specific paralogues, we have studied the ligand-binding capacities of RARs from diverse chordates species. We have found that RAR beta-like binding selectivity is a synapomorphy of all chordate RARs, including a reconstructed synthetic RAR representing the receptor present in the ancestor of chordates. Moreover, comparison of expression patterns of the cephalochordate amphioxus and the vertebrates suggests that, of all the RARs, RAR beta expression has remained most similar to that of the ancestral RAR. On the basis of these results together, we suggest that while RAR beta kept the ancestral RAR role, RAR alpha and RAR gamma diverged both in ligand-binding capacity and in expression patterns. We thus suggest that neofunctionalization occurred at both the expression and the functional levels to shape RAR roles during development in vertebrates.

In many parts of the world, including Cameroon, mycotoxin contamination of groundnuts remains a major constraint affecting their use as food. Understanding the contributing factors is an essential intervention to reduce contamination and people's exposure to these harmful toxins. The aim of this research was to identify the factors associated with the knowledge, perceptions, and postharvest practices of groundnut farmers in three production basins in Cameroon. Data were collected through surveys and analyzed using descriptive methods and logistic regression models. The results show that groundnut farmers are little aware of the existence of mycotoxins (12%) and totally unaware of the existence of aflatoxins (100%). Only 7.1% of these farmers are aware of the effects of mycotoxins on consumer health. After evaluation, the large majority of farmers scored poor marks for knowledge (86%) and practice (98.7%) in the management of mould and mycotoxins in groundnuts. Knowledge of mycotoxins was positively associated with the level of education [OR = 3.42; (95%-IC: 1.00–16.00); p < 0.05 ] and region [OR = 4.49; (95%-IC: 1.09–20.3); p < 0.05 ]. Farmers' good practices were linked to their production experience [OR = 6.06, (95% CI: 0.91-18.4), p = 0.035 ]. The use of mouldy groundnut for feed was associated with age [OR = 3.34, (95% CI: 1.14–10.2), p = 0.03 ], sex [OR = 0. 43, (IC-95%: 1.14–1.05), p = 0.026 ], marital status [OR = 0.35, (IC-95%: 0.14–0.79), p = 0.015 ], and production region [OR = 0.27, (IC-95%: 0.13–0.56)]. In conclusion, groundnut farmers had insufficient knowledge of mycotoxins, no knowledge of aflatoxins, and suboptimal handling and storage practices for this commodity. This contributes to increasing the risk of exposure for the population and requires mitigation measures, including awareness campaigns on mycotoxins, specifically aflatoxins, and capacity building for farmers in terms of storage and postharvest management of foodstuffs. [ABSTRACT FROM AUTHOR]

Inoculation of plants with plant growth-promoting bacteria (PGPB) is an ecological approach to improve plants growth and yield. The objective of this study was to screen native PGPBs in tomato root rhizosphere and evaluate their performance in germination and growth of seedlings in the greenhouse in the western region of Cameroon. Isolates were selected based on their ability to solubilize phosphate, produce indole-3-acetic acid, and improve seed germination and seedling growth under laboratory conditions. Following this screening, eight bacteria were selected (S1, S4, S13, S14, S16, B9, B11, and B15) to assess their performance on seedling growth in greenhouse. Seeds of two tomato varieties (one improved, Raja, and the local one, Foolewouh) were used in this study. The experiment was performed in sterilized and non-sterilized soils. Phylogenetic analysis of the 16S rRNA sequence showed that these bacteria belong to the genus Bacillus, including B. thuringiensis, B. cereus, B. pacificus, and B. aerius. The bacterial performance depended on the variety and conditions of soil treatment. Isolates improved seed germination (up to 31.93%) and seeding strength (up to 78.59%) in vitro. In greenhouse, inoculation with PGPB significantly increased stem height, root length, and weight of fresh and dry stems and roots. Raja variety was more sensitive to bacteria and performed better than the Foolewouh variety. Bacterial isolates on sterilized soil allowed to better seedling growth compared to non-sterilized soil. The study showed that B. thuringiensis (strain B9), B. pacificus (strain B11), and Bacillus sp. (strain B15) can be used as inoculant formulations to improve seedling growth of tomato plant. [ABSTRACT FROM AUTHOR]

Abstract  We study in this article the equivariant Schrödinger map equation in dimension 2, from the Euclidean plane to the sphere. A family of self-similar solutions is constructed; this provides an example of regularity breakdown for the Schrödinger map. These solutions do not have finite energy, and hence do not fit into the usual framework for solutions. For data of infinite energy but small in some norm, we build up associated global solutions. [ABSTRACT FROM AUTHOR]

Abstract.  In the case where the charge of the particle is small compared to its mass, we describe the asymptotics of the Lorentz–Maxwell equation (Abraham model) for any finite-energy data. As time goes to infinity, we prove that the speed of the particle converges to a certain limit, whereas the electromagnetic field can be decomposed into a soliton plus a free solution of the Maxwell equation. It is the first instance of a scattering result for general finite energy data in a field-particle equation. [ABSTRACT FROM AUTHOR]

Engine run-ups are part of the regular maintenance schedule at Vancouver International Airport. The noise generated by the run-ups propagates into neighboring communities, disturbing the residents. Active noise control is a potentially cost-effective alternative to passive methods, such as enclosures. Propeller aircraft generate low-frequency tonal noise that is highly compatible with active control. This paper presents a preliminary investigation of the feasibility and effectiveness of controlling run-up noise from propeller aircraft using local active control. Computer simulations for different configurations of multi-channel active-noise-control systems, aimed at reducing run-up noise in adjacent residential areas using a local-control strategy, were performed. These were based on an optimal configuration of a single-channel control system studied previously. The variations of the attenuation and amplification zones with the number of control channels, and with source/control-system geometry, were studied. Here, the aircraft was modeled using one or two sources, with monopole or multipole radiation patterns. Both free-field and half-space conditions were considered; for the configurations studied, results were similar in the two cases. In both cases, large triangular quiet zones, with local attenuations of 10 dB or more, were obtained when nine or more control channels were used. Increases of noise were predicted outside of these areas, but these were minimized as more control channels were employed. By combining predicted attenuations with measured noise spectra, noise levels after implementation of an active control system were estimated. [ABSTRACT FROM AUTHOR]

We show how the derivation of the Derrida–Lebowitz–Speer–Spohn equation can be prolonged to obtain a new equation, generalizing the models obtained in the paper by these authors. We then investigate its properties from both an analytical and numerical perspective. Specifically, a numerical method is presented to approximate solutions of the prolonged equation. Using this method, we investigate the relationship between the solutions of the prolonged equation and the Tracy–Widom GOE distribution. [ABSTRACT FROM AUTHOR]

This study reports the complications occurred during the management of open fractures of the lower limbs, resulting in secondary amputations, observed in clinicians' practice in recent years as well as different risk factors and possible deficiencies in management at the origin of these complications. We conducted a retrospective study over a period of 06 years (January 2006 - January 2012). It included patients with open fracture of the lower limb initially treated in our institution and whose complications resulted in amputation. All patient undergoing emergency amputation after examination at the Emergency Department were excluded. All patient treated in another hospital before being referred to us were excluded by the study, even if secondary amputation had been performed in our institution. We collected data by analyzing the records of patients (clinical and complementary examinations, surgical reports). We evaluated our management of open fractures of the lower limb according to the guidelines and recommendations found in the literature. These complications were observed in 9 out of 306 open fractures of the lower limb treated in the same period (January 2006 - January 2012), reflecting a rate of 2.9%. The average age was 42.6(26-57) years, all patients were male. We recorded 1 case of fracture of the femur, 7 cases of fracture of 2 leg bones and 1 case of foot crushing. These were open fractures including 1 case of type 1 fracture, 3 cases of type II fracture and 5 cases of type III fracture, according to Gustilo and Anderson classification. We performed 5 amputations of the thigh and 4 amputation of the upper third of the leg. Various complications motivated these amputations, including bone infections or soft-tissue gangrenes of ischemic or infectious origin. The patients had no morbidities such as diabete and were not chronic smokers. No patient died. Open fractures deserve special attention of the surgeon on immediade complications both from a diagnostic and therapeutic point of view in order to reduce the amputation rates after primary surgery giving patients the impression that they had an incorrect procedure performed on them. Particular attention should be paid to the degree of initial contamination and to the presence of a virulent germ at the site of trauma which may motivate particular attitudes during primary management. [ABSTRACT FROM AUTHOR]

Experiments were performed on the rotating platform 14 m in diameter equipped with a simple internal wave generator. Internal waves were generated for a wide range of Coriolis parameters. When the rotation is very weak, i.e., when the internal Rossby radius of deformation is much larger than the wavelength, then the stable nonlinear waves generated are solitary waves. These have a horizontal crest, as in the nonrotating case. When the rotation is strong, i.e., when the internal Rossby radius is at most comparable with the wavelength, then Sverdrup-like periodic waves can be generated, but no solitary wave can then propagate. For the intermediate case, Ostrovsky waves are generated. Their phase speed increases with increasing amplitude. Then, there are two characteristic wave lengths: one which varies with the inverse square root of the amplitude, as for the KdV wave, and the other, linked with the rotation, which varies as the square root of the amplitude. The experimental results are thus in agreement with most of the conclusions in recent analytical developments.

This study reports the complications occurred during the management of open fractures of the lower limbs, resulting in secondary amputations, observed in clinicians' practice in recent years as well as different risk factors and possible deficiencies in management at the origin of these complications. We conducted a retrospective study over a period of 06 years (January 2006 - January 2012). It included patients with open fracture of the lower limb initially treated in our institution and whose complications resulted in amputation. All patient undergoing emergency amputation after examination at the Emergency Department were excluded. All patient treated in another hospital before being referred to us were excluded by the study, even if secondary amputation had been performed in our institution. We collected data by analyzing the records of patients (clinical and complementary examinations, surgical reports). We evaluated our management of open fractures of the lower limb according to the guidelines and recommendations found in the literature. These complications were observed in 9 out of 306 open fractures of the lower limb treated in the same period (January 2006 - January 2012), reflecting a rate of 2.9%. The average age was 42.6(26-57) years, all patients were male. We recorded 1 case of fracture of the femur, 7 cases of fracture of 2 leg bones and 1 case of foot crushing. These were open fractures including 1 case of type 1 fracture, 3 cases of type II fracture and 5 cases of type III fracture, according to Gustilo and Anderson classification. We performed 5 amputations of the thigh and 4 amputation of the upper third of the leg. Various complications motivated these amputations, including bone infections or soft-tissue gangrenes of ischemic or infectious origin. The patients had no morbidities such as diabete and were not chronic smokers. No patient died. Open fractures deserve special attention of the surgeon on immediade complications both from a diagnostic and therapeutic point of view in order to reduce the amputation rates after primary surgery giving patients the impression that they had an incorrect procedure performed on them. Particular attention should be paid to the degree of initial contamination and to the presence of a virulent germ at the site of trauma which may motivate particular attitudes during primary management.