Life cycle studies of the hexose transporter of Plasmodium species and genetic validation of their essentiality

A Plasmodium falciparum hexose transporter (PfHT) has previously been shown to be a facilitative glucose and fructose transporter. Its expression in Xenopus laevis oocytes and the use of a glucose analogue inhibitor permitted chemical validation of PfHT as a novel drug target. Following recent re-annotations of the P. falciparum genome, other putative sugar transporters have been identified. To investigate further if PfHT is the key supplier of hexose to P. falciparum and to extend studies to different stages of Plasmodium spp., we functionally analysed the hexose transporters of both the human parasite P. falciparum and the rodent parasite Plasmodium berghei using gene targeting strategies. We show here the essential function of pfht for the erythrocytic parasite growth as it was not possible to knockout pfht unless the gene was complemented by an episomal construct. Also, we show that parasites are rescued from the toxic effect of a glucose analogue inhibitor when pfht is overexpressed in these transfectants. We found that the rodent malaria parasite orthologue, P. berghei hexose transporter (PbHT) gene, was similarly refractory to knockout attempts. However, using a single cross-over transfection strategy, we generated transgenic P. berghei parasites expressing a PbHT–GFP fusion protein suggesting that locus is amenable for gene targeting. Analysis of pbht-gfp transgenic parasites showed that PbHT is constitutively expressed through all the stages in the mosquito host in addition to asexual stages. These results provide genetic support for prioritizing PfHT as a target for novel antimalarials that can inhibit glucose uptake and kill parasites, as well as unveiling the expression of this hexose transporter in mosquito stages of the parasite, where it is also likely to be critical for survival

Influence of ethephon stimulation on latex physiological parameters and consequences on latex diagnosis implementation in rubber agro-industry

Latex Diagnosis (LD) is currently considered by Cirad and most of its rubber agro-industry partners as a routine physiological tool to optimise, at block level, the rubber yield production of the rubber plantations. Without using LD, a general stimulation recommendation per clone and per tapping year is generally applied at plantation scale, as a function of tapping cut position and direction, whatever the local and actual yield potential is. Even though this general recommendation is based on clonal physiological latex characteristics, such a global approach does not permit to consider the local specificities of the yield potential, as it avoids considering factors like soil heterogeneity, microclimate variations in larger estates and differential expression of diseases (leaf diseases, root diseases...). In this case, plantations are almost "blind" regarding suitability of the applied stimulation intensities, and uniform application of the same rate of stimulant in all homogenous cultural units may sometimes lead to optimised exploitation but may also lead locally to under exploitation in higher yield potential areas or to over exploitation in lower yield potential areas. Using LD permits to optimize the stimulation at local level (decrease of stimulation when an over exploitation is detected, increase of stimulation intensity when an under exploitation is detected) and therefore permits the yield optimisation block per block, taking into account the plantations heterogeneities and therefore the actual local yield potential. Of course, LD interpretation depends on former set up LD parameters reference values. These ones are clonal and established for the 4 parameters used in LD: latex sucrose content, latex inorganic phosphorus content, latex reduced thiols content and DRC/TSC. These LD reference values are established for 5 limit levels (very low, low, normal, high and very high), for each LD parameter (Suc, Pi, RSH and DRC/TSC), either at regional scale or, in case of large estates and companies, at plantation scale when local LD parameters database is large enough. To set up correctly these LD reference values, it is required to know what can be the general evolution of the 4 LD parameters depending on exploitation intensity. These evolutions are detailed in the document. (Résumé d'auteur

L'expérience de l'espoir vécue par des enfants atteints d'un cancer

L'histoire des soins palliatifs pédiatriques est plutôt brève et récente (Canouî, 2003). Si l'association entre « soins palliatifs » et « pédiatriques » étonne, il n'est pas rare que de jeunes enfants meurent de maladies graves comme le cancer. Malheureusement, seulement 5 à 12% des enfants canadiens pouvant bénéficier des services de soins palliatifs reçoivent ces soins spécialisés (Widger et autres, 2007). De plus en plus, les besoins des enfants en fin de vie et ceux de leur famille sont reconnus et, progressivement, les chercheurs commencent à s'intéresser aux soins palliatifs pédiatriques et à les développer. Si l'espoir est par ailleurs nécessaire pour tous les êtres humains positionnés à différents cycles de la vie (Miller, 2007), la promotion de l'espoir chez les enfants constitue l'un des six défis en soins palliatifs pédiatriques (Liben, Papadatou et Wolfe, 2008). Le but de cette étude est donc d'explorer l'expérience de l'espoir vécue par des enfants atteints de cancer et âgés de 9 à 15 ans, au moyen d'une approche d'inspiration phénoménologique. Plusieurs instruments ou stratégies de collecte des données ont été mis en place, notamment les rencontres non officielles, les entrevues semi-structurées, le clavardage, le dessin, le cercle d'émotions/couleurs ainsi que l'observation participante. L'analyse des données a été effectuée en suivant les étapes sous-jacentes à la méthode phénoménologique mise au point par Colaizzi (1978). L'échantillon est composé de huit enfants atteints d'un cancer et âgés de 9 à 15 ans. Quatre dimensions de la description exhaustive de l'expérience de l'espoir ont été identifiées par les participants : éprouver l'intérieur de soi en s'appuyant sur son monde extérieur; vivre un ensemble de sentiments ambivalents; attendre et croire en la fin de son cancer, et, enfin, se projeter vers un devenir ressemblant au passé. Les résultats de cette recherche ont contribué à mettre en évidence l'importance de soutenir l'espoir auprès des enfants atteints d'un cancer

Influence of Ethephon stimulation on latex physiological parameters and consequences on latex diagnosis implementation in rubber agro-industry

Latex Diagnosis (LD) is currently considered by Cirad and most of its rubber agro-industry partners as a routine physiological tool to optimise, at block level, the rubber yield production of the rubber plantations. Without using LD, a general stimulation recommendation per clone and per tapping year is generally applied at plantation scale, as a function of tapping cut position and direction, whatever the local and actual yield potential is. Even though this general recommendation is based on clonal physiological latex characteristics, such a global approach does not permit to consider the local specificities of the yield potential, as it avoids considering factors like soil heterogeneity, microclimate variations in larger estates and differential expression of diseases (leaf diseases, root diseases...). In this case, plantations are almost "blind" regarding suitability of the applied stimulation intensities, and uniform application of the same rate of stimulant in all homogenous cultural units may sometimes lead to optimised exploitation but may also lead locally to underexploitation in higher yield potential areas or to overexploitation in lower yield potential areas. Using LD permits to optimize the stimulation at local level (decrease of stimulation when an overexploitation is detected, increase of stimulation intensity when an underexploitation is detected) and therefore permits the yield optimisation block per block, taking into account the plantations heterogeneities and therefore the actual local yield potential. Of course, LD interpretation depends on former set up LD parameters reference values. These ones are clonal and established for the 4 parameters used in LD: latex sucrose content, latex inorganic phosphorus content, latex reduced thiols content and DRC/TSC. These LD reference values are established for 5 limit levels (very low, low, normal, high and very high), for each LD parameter (Suc, Pi, RSH and DRC/TSC), either at regional scale or, in case of large estates and companies, at plantation scale when local LD parameters database is large enough. To set up correctly these LD reference values, it is required to know what can be the general evolution of the 4 LD parameters depending on exploitation intensity. These evolutions are detailed in the document. (Résumé d'auteur

Lestijoen, Pöntiönjoen, Lohtajanjoen, Viirretjoen ja Koskenkylänjoen vesistöalueiden vesienhoidon toimenpideohjelma 2016-2021

Vesienhoidon keskeisenä tavoitteena on estää jokien, järvien ja rannikkovesien sekä pohjavesien tilan heikkeneminen sekä pyrkiä kaikkien vesien vähintään hyvään tilaan. Erinomaisiksi tai hyviksi arvioitujen vesien tilaa ei saa heikentää. Tavoitteen saavuttamiseksi suunnitellaan ja toteutetaan vesien tilaa parantavia toimenpiteitä ja seurataan niiden vaikutuksia. Vesienhoidossa otetaan huomioon myös merenhoidon, tulvariskien hallinnan sekä luonnonsuojelun tavoitteet. Vesienhoitoa suunnitellaan vesienhoitoalueittain, joita on Manner-Suomessa seitsemän. Vesienhoitoalue muodostuu yhdestä tai useammasta vesistöalueesta. Lestijoen, Pöntiönjoen, Lohtajanjoen, Viirretjoen ja Koskenkylänjoen (Lestijoen ym.) toimenpideohjelman alue kuuluu Kokemäenjoen-Saaristomeren-Selkämeren vesienhoitoalueeseen. Vesienhoidon suunnittelu etenee kuuden vuoden jaksoissa. Ensimmäiset vuoteen 2015 ulottuvat toimenpideohjelmat laadittiin laajassa yhteistyössä vuosien 2008–2009 aikana. Lisätietoa vesienhoidosta ja vesienhoidon järjestämisestä vesienhoitoalueella on saatavilla osoitteessa www.ymparisto.fi/lantinenvesienhoitoalue sekä Kokemäenjoen - Saarisromeren – Selkämeren vesienhoitoalueen vesienhoitosuunnitelmasta. Vesienhoitosuunnitelmassa esitellään tarkemmin vesienhoitoon liittyvä lainsäädäntö ja vesienhoitoon liittyvät muut suunnitelmat ja strategiat. Lisäksi vesienhoitosuunnitelmassa on tehty koko vesienhoitoaluetta koskava vaihtoehtotarkastelu vesienhoi-don toimenpiteistä

Differences in the Components and Relations of a Multidimensional Model of Reading Comprehension in Low and Average 8- to 11-Year-Old French Readers.

International audienceIf the simple view of reading earlier characterised reading comprehension as a product of decoding and linguistic comprehension, research has evolved to a more complex simple view including speed or fluency as a major factor of reading comprehension. Through this complex simple view approach, multidimensional models of reading comprehension emerged, which, in addition, proposed the implication of other cognitive skills. The purpose of our study is; Firstly, as we hypothesised a structural theoretical model of the relationships between oral language skills, decoding and word fluency, oral text comprehension, reading fluency and reading comprehension, we want to test if this model fits the data obtained from 8 to 11-year-old French students and to identify the contribution and relations of each skill to reading comprehension. Secondly, we want to explore the relations of text fluency with other components of the model and with reading comprehension. Thirdly, we try to identify variations of the relations between these components according to the average or low level of reading achievement of pupils. The results obtained by studying differences in the relationships between multiple predictors of reading comprehension for low and average primary school readers seem to indicate that proficiency in reading is acquired by passing from an independent participation of the OLS and WLS to reading comprehension, as stated by the simple view of reading, to a more integrated functioning with some links between these two groups of skills, which calls for more complex views of reading