Commerce international de l’eau et la relation nord-sud

Ce travail scientifique a pour but de comprendre l’impact de la relation Nord-Sud sur le commerce international de l’eau. Dans ce contexte, moyennant un modèle de gravité estimé PPML robuste à l’hétéroscédasticité et avec des effets fixes individuels par an pour l’exportateur et l’importateur et en se basant sur des données relatives à 238 pays dans le monde durant la période comprise entre 1996 et 2017, j’ai pu découvrir qu’à l’échelle international, le flux de commerce international de l’eau où un des partenaires commerciaux est un pays du Nord et l’autre est du Sud n’est pas le flux commercial dominant et que le commerce entre 2 pays du Sud est le flux de commerce qui a accapare la majorité des flux du commerce de ce bein. De plus, la distance demeure toujours une friction du commerce. Cependant, en se focalisant juste sur les flux de commerce de type Nord-Sud, je viens de constater que les pays du Nord ont tendance à importer l’eau comme inputs pour leurs productions et ainsi garder le niveau de développement en dépit de la distance. De plus, l’importance des accords bilatéraux entre le Nord et le Sud et l’aide faite par le Nord au Sud favorisent l’importation d’eau par le Nord. Cependant, si on se concentre sur les pays du Sud qui sont exportateurs d’eau, il est remarquable que le cas diffère selon les pays. En effet, certains sont très riches en eau et ce bien demeure la source majeure de croissance économique ; cependant, d’autres sont pauvres en cette ressource et, à cause de l’instabilité politique et l’inefficacité des gouvernements, ces nations demeurent encore des exportateurs d’eau. De plus, au niveau des pays du Sud, à cause de l’aide donnée par le Nord au Sud et malgré la pauvreté au niveau de dernier, plus le pays du Sud est pauvre, plus il a tendance à exporter de l’eau

Novi sublingviformni vulvarni zalistak oblića Haemonchus sp. u prirodno invadiranih domaćih preživača zaklanih u klaonici Béja u sjevernom Tunisu.

The present study was conducted to determine the type of vulvar morphology in female Haemonchus worms collected from the abomasa of sheep, goats and cattle slaughtered for human consumption in Béja Abattoir in Tunisia with a Mediterranean type of climate. For the purpose, a total of 2450 female Haemonchus worms from abomasa of 363 sheep, 258 goats and 152 cattle were thoroughly examined for the types of their vulvar flap. Of the total 143 female Haemonchus worms from cattle 21.5% linguiform, 41.8% knobbed and 3.4% smooth vulvar flap types were recorded. Out of the total 645 female Haemonchus worms from abomasa of sheep, 42.5% linguiform, 36.3% knobbed and 21.2% smooth vulvar morph types were identified. In goats a total of 1662 female worms were differentiated into 27.7% linguiform, 65.8% knobbed and 6.4% smooth vulvar morph types. Further subclassification of 43 linguiform vulvar flap female Haemonchus worms from cattle revealed an overall proportion of 11.5% LA type, 26.3% LB type, 17.1% LC type, 0.8% LD type and 11.0% LI linguiform subtypes. Likewise, from sheep, of the total of 327 linguiform vulvar flap female worms, 31.6% LA type, 18% LB type, 26.3% LC type, 3.9% LD type and 3.5% LI linguiform subtypes were differentiated. From goats, of the total of 461 linguiform vulvar flap female worms, 48% LA type, 13.8% LB type, 21.6% LC type, 4.4% LD type and 12.3% LI linguiform subtypes were detected. The LB sublinguiform type had the highest overall proportion in cattle, whereas the LA sub linguiform type was the most predominant in both sheep and goats. An interesting finding of the current study is the documentation of a new type of sublinguiform vulvar flap type in female Haemonchus worms for the first time, from the Mediterranean type of climate in Tunisia. To the best of our knowledge this is the first report of new vulvar morphology in female Haemonchus worms, designated as LD sublinguiform vulvar flap with three cuticular inflations. Further detailed studies are urgently needed on the prevalence, morphological, molecular and genetic characterization of Haemonchus spp. with different vulvar flap types in different agro-ecologies, animal species and breeds, and management systems in Tunisia and other countries.Istraživanje je poduzeto kako bi se odredio morfološki tip ženki oblića roda Haemonchus sakupljenih iz sirišta ovaca, koza i goveda zaklanih u klaonici Béja na području Tunisa s mediteranskom klimom. Ukupno je bilo izdvojeno 2450 ženki oblića roda Haemonchus iz sirišta 363 ovce, 258 koza i 152 goveda. Nakon izdvajanja određivane su razlike u izgledu vulvarnog zaliska. Od ukupno 143 ženke izdvojene iz sirišta goveda 21,5% je imalo lingviformni tip zalistaka, 41,8% zalistak s izbočinom dok je samo 3,4% imalo glatke zaliske. Među oblićima (645) izdvojenima iz ovaca ustanovljeno je 42,5% s lingviformnim zaliskom, 36,3% sa zaliskom s izbočinom i 21,2% oblića s glatkim zaliskom. Mikroskopskim pregledom 1662 ženke izdvojene iz koza u njih 27,7% ustanovljeni su lingviformni zalisci, u 65,8% zalisci s izbočinom te u 6,4% glatki zalisci. Daljnjim svrstavanjem 43 ženke s lingviformnim zaliscima podrijetlom iz goveda pokazalo se da 11,5% pripada LA podtipu, 26,3% LB podtipu, 17,1% LC podtipu, 0,8% LD podtipu i 11,0% LI podtipu. Među 325 oblića s lingviformnim zaliscima izdvojenih iz ovaca 31,6 % je bilo LA podtipa, 18% LB podtipa, 26,3% LC podtipa, 3,9% LD podtipa i 3,5% LI podtipa. Među 461 oblićem s lingviformnim zaliscima podrijetlom iz koza 48% bilo je LA tipa, 13,8% LB tipa, 21,6% LC tipa, 4,4% LD tipa i 12,3% LI podtipa. LB tip zaliska bio je najučestaliji u oblića izdvojenih iz goveda dok je LA bio najčešći tip zaliska u oblića izdvojenih iz ovaca i koza. Ovo je prvi nalaz novog tipa sublingviformnih vulvarnih zalistaka u ženki oblića roda Haemonchus na području Tunisa s mediteranskom klimom. Taj zanimljiv novi nalaz sublinguiformnog vulvarnog zaliska s tri kutikularna udubljenja nazvan je LD tip

Toxoplasma gondii infection and toxoplasmosis in North Africa: a review

Toxoplasmosis is an important zoonosis caused by an obligate intracellular parasitic protozoan, Toxoplasma gondii. The disease is distributed worldwide and can affect all warm-blooded vertebrates, including humans. The present review aimed to collect, compile and summarize the data on the prevalence of T. gondii infection in humans and animals in the five North African countries (Morocco, Algeria, Tunisia, Libya and Egypt). Published data from national and international databases were used. Distribution patterns and risk factors for T. gondii infection are discussed, focusing on biotic and abiotic factors. This review is a comprehensive epidemiological analysis of T. gondii infection in North Africa and will therefore be a useful tool for researchers. It can also be used to propose or enhance appropriate national toxoplasmosis control programs

Prevalence of

Dermanyssus gallinae (Mesostigmata: Dermanyssidae), a mite of poultry, represents the most important ecotoparasite of egg-laying poultry in several countries. We estimated the prevalence of D. gallinae infestation in 38 industrial poultry farms (28 egg-laying and 10 reproductive hen farms) in the governorate of Nabeul (North-East Tunisia). Traps were placed in two locations of each farm during 24 h in August. The overall prevalence at the farms was estimated to be 34%. A total number of 329 D. gallinae were collected, giving an intensity of 0.0028 and an abundance of 0.0015. Infestation intensity and abundance were significantly higher in egg production farms than reproductive farms. There was no correlation between the intensity of infestation and temperature. An exponential correlation was observed between the birds’ age and infestation intensity. We recommend a systematic survey of poultry farms during the whole breeding period. Prompt treatment is recommended to avoid the exponential increase of mite population

PARASITES BOVINS ALGERIE CEVA 2018.pptx

Présentation sur les parasites des bovins en Algérie

(Acari, Ixodidae) in northeast Tunisia: seasonal population dynamics of nymphs and adults on field cattle

Hyalomma scupense is a two-host tick infesting mainly cattle representing in North Africa the vector of tropical theileriosis (Theileria annulata infection), a major tick-borne disease affecting cattle. Any effective control programme of ticks requires a good knowledge of the biology of the target species. In the present study, three cattle farms in northeast Tunisia were surveyed during the activity seasons for adult and nymphs of Hyalomma scupense. Several indicators were studied, including chronological indicators, infestation prevalence, infestation intensity and feeding predilection sites of the ticks. The adult ticks were present from mid-June to late November. Nymphs were observed on animals from early September to late November. A large proportion of the ticks were attached in the posterior udder quarters: 41% and 64% of adult ticks and nymphs, respectively. The animals that were heavily infested by adult ticks were also heavily infested by nymphs. Moreover, 17% of adult ticks and 53% of nymphs were present on only 5% of cattle population. These data are important for the success of targeted acaricide application leading to a dramatic decrease of acaricide quantity needed for the treatment. When the preferential sites of attachment are known, the effectiveness of manual removal of ticks can be improved. The presence of highly infested animals is to be considered when any control programme is implemented, since these animals harbour a high proportion of the ticks

SURRA CNOMVT 2018

Présentation sur le surra en Tunisie

A climate-based model for tick life cycle: positive semigroup theory on Cauchy problem approach

The distribution of ticks is essentially determined by the presence of climatic conditions and ecological contexts suitable for their survival and development. We build a model that explicitly takes into account each physiological state through a system of infinite differential equations where tick population density are structured on an infinite discrete set. We suppose that intra stage development process is temperature dependent (Arrhenius temperatures function) and that larvae hatching and adult mortality are temperature and water vapor deficit dependent. We analysed mathematically the model and have explicit the R0 of the tick population

Hd86 mRNA expression profile in Hyalomma scupense life stages, could it contribute to explain anti-tick vaccine effect discrepancy between adult and immature instars?

International audienceBm86 midgut protein has been used in order to control ticks of the Hyalomma genus. Previous studies demonstrated the inefficacity of this antigen in the control of Hyalomma scupense, whereas recombinant Hd86 antigen, the Bm86 ortholog in H. scupense produced in Pichia pastoris, was protective against larval H. scupense tick stage infestations but ineffective in the control of the adult stage. One possible explanation for this result is the variation in Hd86 expression levels between these two developmental stages. To test this hypothesis, Hd86 mRNA levels were characterized in H. scupense developmental stages. The expression profile of Hd86 demonstrated a significant variation between tick life stages and showed a significant reduction in the number of transcripts during feeding and, particularly after molting to adults. The most interesting result was noted after molting of engorged nymphs in unfed adults where the expression levels decreased significantly by 12.78 (10.77-17.39) (p<0.001) and 9.25 (5.77-15.72)-fold (p<0.001) in unfed males and unfed females, respectively. Comparing unfed nymphs to unfed adult ticks, the Hd86 expression levels decreased by 13.82 (5.39-24.45) (p=0.035) and 9.93 (2.87-22.08)-fold (p=0.038) in males and females respectively. Lower Hd86 mRNA levels in adult ticks should result in lower protein levels and thus less antibody-antigen interactions necessary for vaccine efficacy in ticks fed on vaccinated animals. Thus, the observed differences in Hd86 expression profile between immature and adult stages might explain, in part, the discrepancy of the Hd86 vaccine efficacy against these two life stages of H. scupense