Effets de la couverture des cages flottantes et de la période de distribution de l\'aliment sur la survie et la croissance des alevins du poisson-chat africain Heterobranchus longifilis Valenciennes 1840 en élevage intensif

L\'influence du recouvrement des cages flottantes par des bâches plastiques noires non transparentes et de la période (jour ou nuit) de distribution de l\'aliment sur la survie et la croissance du poisson-chat africain Heterobranchus longifilis a été évaluée. L\'expérience a consisté à observer le jour et la nuit des alevins nourris en quatre repas, dans deux types de cages flottantes : cages couvertes et cages non couvertes. Quelle que soit la période de distribution de l\'aliment, les meilleurs taux de survie ont été observés dans les cages couvertes (73,0 ± 2,6 % le jour et 75,0 ± 1,7 % la nuit contre 64,0 ± 3,5 % le jour et 67,0 ± 2,0 % la nuit). Les poids moyens finaux des poissons enregistrés dans ces cages sont de 16,9 ± 1,9 g le jour et 17,8 ± 1,9 g la nuit. Ces poids sont comparables à ceux observés dans les cages non couvertes avec distribution nocturne de l\'aliment (16,8 ± 1,1 g). Ces résultats montrent qu\'en cages couvertes, la période de distribution de l\'aliment n\'a aucune influence sur la croissance des poissons.The effects of covering the breeding floating cages with a black plastic canvas and the feeding period (day or night) on the survival and growth of the african cat-fish Heterobranchus longifilis have been investigated. Juvenile individuals of this species fed four times during daytime and nighttime were reared in two types of floating cages : covered with black plastic canvas and without any canvas. Whatever the feeding period, the best survival rates were recorded in covered cages (73,0 ± 2,6 % for daytime and 75,0 ± 1,7 % for nighttime, against 64,0 ± 3,5 % for daytime and 67,0 ± 2,0 % for nighttime). In these cages, final mean weights of fishes recorded were 16,9 ± 1,9 g for daytime and 17,8 ± 1,9 g for nighttime. These data were similar to those recorded in non covered floating cage with nighttime feeding. Results suggest that there is no effect of the feeding period on the growth of H. longifilis reared in cages with canvas. Keywords: Heterobranchus longifilis, alevinage, cage flottante, éclairement, horaires de nourrissage./Heterobranchus longifilis, fry rearing, floating cage, light, feeding time.Sciences & Nature Vol. 4 (1) 2007: pp. 85-9

Variations saisonnières des indices épidémiologiques de trois monogènes parasites de Sarotherodon melanotheron (pisces : Cichlidae) dans le lac d’ayamé i (Côte d’Ivoire)

La dynamique saisonnière des populations de trois espèces de monogènes branchiaux du poisson Sarotherodon melanotheron Rüppel, 1852 a été étudiée dans le lac du barrage d’Ayamé I, situé dans le sud-est de la Côte d’Ivoire. La présente étude, menée entre août 2004 et juillet 2005, a porté sur 412 poissons. Une étude qualitative et quantitative a été effectuée à l’aide d’une loupe binoculaire et d’un microscope. Ce travail a montré que l’infestation de ce poisson par Cichlidogyrus acerbus, C. halli et Scutogyrus minus varie en fonction des saisons. Les plus fortes valeurs d’intensités moyennes, de prévalences et d’abondances ont été observées pendant la grande saison des pluiestandis que les plus faibles ont été notées en grande saison sèche. Par ailleurs, l’étude a révélé que le nombre de parasites croît avec la taille du poisson. En revanche, le parasitisme évolue indépendamment du sexe.The seasonal dynamics of the population of three Monogenean gill parasites of the black-chinned tilapia Sarotherodon melanotheron Rüppel, 1852, was carried out in man-made Lake Ayame I (South eastern Côte d’Ivoire) between August 2004 and July 2005. A total of 412 hosts individuals were examined. A qualitative and quantitative study has been undertaken using a binocular microscope and a microscope. It showed seasonal variations of this fish infection by Cichlidogyrus acerbus, C. halli and Scutogyrus minus. Furthermore, higher mean intensities of infestation, prevalences and abundances were registered during the long rainy season and, the low ones in the long dry season. The result also revealed that the number of parasites increase in relation to fish length. Host sex was found to have no effect on the three groups of parasites.Mots-clés: Monogènes parasites, Sarotherodon melanotheron, lac d’Ayamé I, Côte d’Ivoire

Régime alimentaire de Distichodus rostratus (Characiformes, Distichodontidae) dans un bassin Ouest africain (fleuve Bandama, Côte d\'Ivoire)

La morphologie du tube digestif et le régime alimentaire en fonction du stade de maturité et de la saison de Distichodus rostratus (Günther, 1864) ont été étudiés en milieu naturel entre deux barrages hydroélectriques du fleuve Bandama (Kossou et Taabo). L\'analyse a porté sur 220 individus de longueur standard comprise entre 131 et 610 mm. La description du tube digestif a révélé la présence d\'un estomac peu développé et un intestin long (2,34 < CI < 5,16), rapprochant ainsi l\'espèce de la catégorie des poissons phytophages. D. rostratus consomme essentiellement des macrophytes (Ip = 99,98%) surtout de Cymodecea sp. (Ip = 57,8 %) et de débris végétaux (Ip = 41,4 %). L\'indice de Schoener ( ) montre de façon générale une grande similitude du régime alimentaire des poissons en fonction de la taille et des saisons.Studies of the digestive tract morphology and the feeding habits of Distichodus rostratus from the hydrosystem located between the hydroelectric dams of Kossou and Taabo (Bandama river) is undertaken for the first time. About 220 individuals of measuring between 131 and 610 mm length were examined. The digestive tract morphology had less developed stomach with a relatively long intestine (2,34 < CI < 5,16) allowing the classification this species as a micro/ macrophytophagous fish. The identification of the items found the stomach contents revealed that the dominants food items were the Cymodocea sp. (Ip = 57,8 %) and macrophyte fragments (Ip = 41,4 %) in general. Young specimens food fed on mainly macrophyte fragments (Ip = 61,5 %) and Cymodocea sp. (Ip = 38,4 %). Or while adults were concern with the Cymodocea sp. (Ip = 66,5 %) and macrophyte fragments (Ip = 31,2 %). The macrophyte fragments (Ip = 52,18%) was mainly eaten during the dry season whereas Cymodocea sp. (Ip = 64,3 %) was mainly eaten during the rainy season. Schoener overlap index showed the similary in the diet composition in relation with size of the fishes and with the season. Keywords: Distichodus rostratus- Diet - Bandama River - Côte d\'Ivoire.Sciences & Nature Vol. 5 (2) 2008: pp. 167-17

Biological specifics of exogenous development of Oxyuris equi nematodes (Nematoda, Oxyuridae)

Helminths of the species Oxyuris equi Schrank, 1788 are pathogens of domestic and wild odd-toed ungulates. They parasitize in the large intestine of horses, causing colitis and dermatitis at the tail root area. The wide distribution and overall persistence of this species is significally promoted by the specifics of its development and reproduction. Here we studied the specifics of the exogenous development of O. equi nematodes parasitizing Equidae in respect to the factor of temperature and the morphometric changes in oxyuris eggs at different stages of embryogenesis. In laboratory culture of O. equi eggs obtained from female gonads, the embryogenesis occurs in four stages: morula, formation of bean-like embryo, formation of non-invasive larva and formation of infectious larva. The stages of development differ by the morphological parameters. It is established that the development of O.&nbsp;equi eggs is directly related to temperature. The optimal temperature for embryogenesis is 25 °С, at which the highest survival rate of infectious eggs, 81.3%, was observed. At 20 °С and 15 °С the survival of eggs decreased during culturing and the ratios of infectious eggs were 75.7% and 67.3%, respectively. Accordingly, 24.3% and 32.7% of eggs died during development. The temperature also affects the duration of development of O. equi eggs. At 25 °С, the development of Oxyuris eggs was the fastest and occurred in two days. With temperature falling to 20 and 15 °С, the duration of egg development slowed to three and five days, respectively. The process of embryogenesis in Oxyuris is associated with changes in metrical parameters. The length, width and area of egg surface increased. Length and width of egg plug, and shell width of mature Oxyuris eggs decreased. The obtained data on the duration and specifics of exogenous development of parasitic O. equi nematodes will allow effective control measures for horse oxyurosis to be developed

Assessing the feasibility of a sea otter reintroduction to Oregon through a coupled natural-human lens

Sea otters fulfill a keystone role in several Northeastern Pacific nearshore ecosystems. However, their influence has been absent in Oregon coastal waters since their extirpation in the 19th and early 20th century. Interest has been growing for a translocation attempt to reintroduce sea otters to Oregon from one or more source populations of the southern sea otter and northern sea otter subspecies. Numerous unanswered questions require inquiry before a productive discussion can take place on the advisability of such an effort. A successful reintroduction would alter the existing coupled natural-human system dynamics between Oregon coastal communities, Oregon residents as a whole, and the nearshore environment. The appropriate source of reintroduction stock bears discussion, as do the optimal sites on the Oregon coast for a translocation effort and stakeholders’ attitudes towards such a proposal. This paper considers select issues related to the genetics, ecology, and human dimensions of a potential Oregon sea otter reintroduction, integrating insights from each discipline to provide a preliminary interdisciplinary examination

Electrical resistivity and ultrasonic measurements during sequential fracture test of cementitious composite

Cracks in cover of reinforced and pre-stressed concrete structures significantly influence the ingress of deleterious species causing decrease in durability of these structures. The paper is focused on the effect of fracture process on two selected physical parameters of concrete – the electrical resistivity and the ultrasonic pulse passing time – which might be employed as the quality indicator of concrete cover within (nondestructive) procedure(s) of assessment of the structural durability. The concrete electrical resistivity and ultrasonic passing time were investigated here with respect to two variants of treatment of the test specimens’ surface (the pre-dried surface and the wet surface). Test configuration of three-point bending of notched beam was utilized to control the crack propagation; the fracture process passed through several loading–unloading sequences between which the electrical resistivity and ultrasonic passing time readings over the fractured region were performed. Equivalent elastic crack model was used for estimation of the fracture advance (described via the effective crack length) at the loading stages corresponding to the resistivity and ultrasonic measurements. Relationships between changes of both the concrete resistivity and ultrasonic pulse passing time and the effective crack length is determined and discussed

Community-based wound management in a rural setting of Côte d'Ivoire

BACKGROUND: Wounds are a neglected health problem in rural communities of low-income countries, mostly caused by trauma and ulcerative skin diseases including Neglected Tropical Diseases (NTDs) and associated with systemic complications and disability. Rural communities have limited access to high quality health services-based wound care. METHODS: We conducted a prospective observational study on wound management at three levels-community (C), health centre (HC), district hospital (DH)-in a rural community of Cote d'Ivoire. Patients with skin wounds actively identified in a house-to-house survey and passively in the health services in a defined area of the Taabo Health and Demographic Surveillance System were asked to participate and followed-up longitudinally. Endpoints were proportion of wounds closed, time to wound closure, wound size over time, frequency of secondary bacterial infection, need for recapturing after follow-up interruption, and duration of treatment stratified by health service level and wound aetiology. RESULTS: We enrolled 561 patients with 923 wounds between May 2019 and March 2020. The observation period ended in March 2021. Median age was 10 years (IQR 7-15), 63.0% of patients were male. Almost all (99.5%, 870/874) wounds closed within the observation period, 5.3% (49/923) were lost to follow-up. Wounds primarily treated in C, HC and DH closed within a median time of 10, 16 and 170 days, respectively. Median time to acute wound and chronic wound closure was 13 and 72 days, respectively. Wounds treated in C, HC and DH presented with secondary bacterial infections in 10.3% (36/350), 31.0% (133/429) and 100% (5/5) of cases, respectively. Recapturing was required in 68.3% (630/923) of wounds with participants reporting wound closure as the main reason for not attending follow-up. CONCLUSIONS: We describe a wound management model based on national and WHO recommendations focusing on early identification and treatment in the community with potential for broad implementation in low-income countries. TRIAL REGISTRATION: Registration at ClinicalTrials.gov (NCT03957447)

Skin wounds in a rural setting of Côte d'Ivoire: population-based assessment of the burden and clinical epidemiology

BACKGROUND: Data on the burden and clinical epidemiology of skin wounds in rural sub-Saharan Africa is scant. The scale of the problem including preventable progression to chronic wounds, disability and systemic complications is largely unaddressed. METHODS: We conducted a cross-sectional study combining active (household-based survey) and passive case finding (health services-based survey) to determine the burden and clinical epidemiology of wounds within the Taabo Health and Demographic Surveillance System (HDSS) in rural Cote d'Ivoire. Patients identified with wounds received free care and were invited to participate in the wound management study simultaneously carried out in the survey area. The data were analysed for wound prevalence, stratified by wound and patient characteristics. RESULTS: 3842 HDSS-registered persons were surveyed. Overall wound prevalence derived from combined active and passive case finding was 13.0%. 74.1% (403/544) of patients were below the age of 15 years. Most frequent aetiologies were mechanical trauma (85.3%), furuncles (5.1%), burns (2.9%) and Buruli ulcer (2.2%). Most wounds were acute and smaller than 5 cm2 in size. 22.0% (176/799) of wounds showed evidence of secondary bacterial infection. 35.5% (22/62) of chronic wounds had persisted entirely neglected for years. Buruli ulcer prevalence was 2.3 per 1000 individuals and considerably higher than expected from an annual incidence of 0.01 per 1000 individuals as reported by WHO for Cote d'Ivoire at the time of the study. CONCLUSIONS: Skin wounds are highly prevalent in rural West Africa, where they represent a widely neglected problem. The HDSS-based survey with combined active and passive case finding adopted in this study provides a better estimate than school- and health institution-based surveys which underestimate the frequency of skin wounds and, particularly, of neglected tropical diseases of the skin, such as Buruli ulcer and yaws. A comparison with country-specific WHO data suggests underreporting of Buruli ulcer cases. TRIAL REGISTRATION: Registration at ClinicalTrials.gov NCT03957447

Study of the low-temperature behavior of a disordered antiferromagnet with random fields by the parallel-tempering method

The parallel-tempering method has been applied to numerically study the thermodynamic behavior of a three-dimensional disordered antiferromagnetic Ising model with random fields at spin concentrations corresponding to regions of both weak and strong structural disorder. An analysis of the low-temperature behavior of the model convincingly shows that in the case of a weakly disordered samples there is realized an antiferromagnetic ordered state, while in the region of strong structural disorder the effects of random magnetic fields lead to the realization of a new phase state of the system with a complex domain structure consisting of antiferromagnetic and ferromagnetic domains separated by regions of a spin-glass phase and characterized by a spinglass ground state.Comment: 12 RevTeX pages, 8 figure