New methods for chicken embryo manipulations

The capacity to image a growing embryo while simultaneously studying the developmental function of specific molecules provides invaluable information on embryogenesis. However, until recently, this approach was accomplished with difficulty both because of the advanced technology needed and because an easy method of minimizing damage to the embryo was unavailable. Here, we present a novel way of adapting the well-known EC culture of whole chick embryos to time-lapse imaging and to functional molecular studies using blocking agents. The novelty of our method stems from the ability to apply blocking agents ex ovo as well as in ovo. We were able to study the function of a set of molecules by culturing developing embryos ex ovo in tissue culture media containing these molecules or by injecting them underneath the live embryo in ovo. The in ovo preparation is particularly valuable, because it extends the period of time during which the developmental function of the molecule can be studied and it provides an easy, reproducible method for screening a batch of molecules. These new techniques will prove very helpful in visualizing and understanding the role of specific molecules during embryonic morphogenesis, including blood vessel formation

Federalism and the Arab League: A theoretical synergy

Abstract. The paper is a theoretical analogy of the Arab league as a regional organization. The paper also discusses the objectives, strengths and weaknesses of the league. By adopting descriptive-historical research from library instrument, findings show that, there is no doubt that the league had recorded some appreciable level of achievements since its inception and there have equally been some challenges along the line. The paper concludes that, the Arab league must find a way to reduce the perpetual tension and violence in Palestine by working towards enthroning a peaceful relationship with Israel while retaining their cultural identity. The paper also recommends that, the Arab league should strengthen their relationship with the non-Arab Nations especially in the face of globalization to reap the benefits therein involved as a league. Arab league must ensure that Arab states stop waging needless wars between and among themselves. The Syria and Yemeni crises among others is a disgrace to the Arab world.Keywords: Arab league, Theoretical, Synergy, Federalism, Integration.JEL. A10, F15

Toxic effects of estradiol E2 on development in the European tree frog (Hyla arborea)

Estrogenic hormones are a major environmental threat to aquatic wildlife. Here we report chronic toxic effects of exposure to the naturally excreted estrogen, 17β-estradiol (E2), on the larval and subadult development of the European tree frog (Hyla arborea), by an experimental setting and long-term monitoring. In addition to the documented impact on sexual development and mating behavior, the general toxicity of human-released estrogens may contribute to global amphibian declines

Stratégie d'amélioration du service de l'eau et impacts sur les performances de l'irrigation dans le périmètre de la Moulouya

International audienceL'aridité du climat, l'irrégularité des précipitations, ainsi que les sécheresses de plus en plus fréquentes font de l'irrigation un impératif technique incontournable dans la politique de développement agricole et rural au Maroc. Le périmètre irrigué de la Moulouya est un exemple de l'importance de l'irrigation en agriculture. Le système d'irrigation gravitaire y est dominant, l'irrigation par aspersion concerne 22 % des surfaces et l'irrigation localisée 3,5 %, l'arboriculture fruitière couvre plus du tiers des surfaces, la betterave à sucre 4 000 ha, et la céréaliculture 15 000 ha. En effet, disposant d'atouts importants, (superficie équipée en ” grande hydraulique ” de 65 000 ha, sols très favorables, savoir-faire capitalisé par les fermiers, la proximité du marché européen et un tissu agro-industriel prometteur), le périmètre de la Moulouya est confronté à des contraintes techniques qui menacent l'agriculture (réduction de plus de la moitié des capacités de stockage à cause de l'envasement des barrages, variabilité des apports d'eau, vétusté des infrastructures hydro-agricoles, usage mixte des canaux principaux, morcellement des terres). Pour atténuer ces contraintes, l'Office régional de mise en valeur agricole de la Moulouya (couvrant une zone de 550 000 ha) a mis en oeuvre un plan d'amélioration du service de l'eau qui comprend la réhabilitation des infrastructures, la promotion de mesures pour économiser l'eau et le développement du management participatif. Il représente le deuxième projet d'amélioration de la grande irrigation (PAGI 2) financé par la Banque mondiale et se poursuit au sein du projet de réhabilitation de la grande irrigation (PRGI) financé par la Banque europ éenne d'investissement. La mise en oeuvre de ces actions a induit l'amélioration des performances de l'irrigation, que reflètent plusieurs indicateurs : l'efficience, le taux de maintenance, la disponibilité opérationnelle des réseaux d'irrigation, des critères ayant trait à l'économie de l'eau et à l'implication des usagers dans la gestion de l'eau. Le maintien du niveau de performance, résultant de ces projets, dépend de l'harmonisation des efforts attendus de tous les intervenants locaux et nationaux, et plus particulièrement de la participation des agriculteurs au sein des associations et de leur contribution aux économies d'eau à la parcelle

A large-scale proteogenomics study of apicomplexan pathogens-Toxoplasma gondii and Neospora caninum

Proteomics data can supplement genome annotation efforts, for example being used to confirm gene models or correct gene annotation errors. Here, we present a large‐scale proteogenomics study of two important apicomplexan pathogens: Toxoplasma gondii and Neospora caninum. We queried proteomics data against a panel of official and alternate gene models generated directly from RNASeq data, using several newly generated and some previously published MS datasets for this meta‐analysis. We identified a total of 201 996 and 39 953 peptide‐spectrum matches for T. gondii and N. caninum, respectively, at a 1% peptide FDR threshold. This equated to the identification of 30 494 distinct peptide sequences and 2921 proteins (matches to official gene models) for T. gondii, and 8911 peptides/1273 proteins for N. caninum following stringent protein‐level thresholding. We have also identified 289 and 140 loci for T. gondii and N. caninum, respectively, which mapped to RNA‐Seq‐derived gene models used in our analysis and apparently absent from the official annotation (release 10 from EuPathDB) of these species. We present several examples in our study where the RNA‐Seq evidence can help in correction of the current gene model and can help in discovery of potential new genes

Recent advances in arsenic trioxide encapsulated nanoparticles as drug delivery agents to solid cancers

Since arsenic trioxide (ATO) was first approved as the front line therapy for acute promyelocytic leukemia (APL) 25 years ago, its anti-cancer properties for various malignancies have been under intense investigation. However, the clinical successes of ATO in treating hematological cancers have not been translated to solid cancers. This is due to arsenic’s rapid clearance by the body’s immune system before reaching the tumor site. Several attempts have henceforth been made to increase its bioavailability toward solid cancers without increasing its dosage albeit without much success. This review summarizes the past and current utilization of ATO in the medical field with primary focus on the implementation of nanotechnology for ATO delivery to solid cancer cells. Different approaches that have been employed to increase arsenic’s efficacy, specificity and bioavailability to solid cancer cells were evaluated and compared. The potential of combining different approaches or tailoring delivery vehicles to target specific types of solid cancers according to individual cancer characteristics and arsenic chemistry was proposed and discussed

Therapeutic potential of delivering arsenic trioxide into HPV-infected cervical cancer cells using liposomal nanotechnology

Arsenic trioxide (ATO) has been used successfully to treat acute promyelocytic leukaemia, and since this discovery, it has also been researched as a possible treatment for other haematological and solid cancers. Even though many positive results have been found in the laboratory, wider clinical use of ATO has been compromised by its toxicity at higher concentrations. The aim of this study was to explore an improved method for delivering ATO using liposomal nanotechnology to evaluate whether this could reduce drug toxicity and improve the efficacy of ATO in treating human papillomavirus (HPV)-associated cancers. HeLa, C33a, and human keratinocytes were exposed to 5 μm of ATO in both free and liposomal forms for 48 h. The stability of the prepared samples was tested using inductively coupled plasma optical emission spectrometer (ICP-OES) to measure the intracellular arsenic concentrations after treatment. Fluorescent double immunocytochemical staining was carried out to evaluate the protein expression levels of HPV-E6 oncogene and caspase-3. Cell apoptosis was analysed by flow cytometry. Results showed that liposomal ATO was more effective than free ATO in reducing protein levels of HPV-E6 and inducing cell apoptosis in HeLa cells. Moreover, lower toxicity was observed when liposomal-delivered ATO was used. This could be explained by lower intracellular concentrations of arsenic. The slowly accumulated intracellular ATO through liposomal delivery might act as a reservoir which releases ATO gradually to maintain its anti-HPV effects. To conclude, liposome-delivered ATO could protect cells from the direct toxic effects induced by higher concentrations of intracellular ATO. Different pathways may be involved in this process, depending on local architecture of the tissues and HPV status