36 research outputs found
Effet antibiose de quatre cultivars de bananier et bananiers plantains sur Cosmopolites sordidus Germar (Coleoptera: Curculionidae) à Kisangani, RD Congo
Black weevil (Cosmopolites sordidus Germar) development on bananas and plantains (Musa sp.) was assessed on four cultivars named: Libanga likale (AAB), Litete (AAB), Lokusu (AAB) and Yangambi Km5 (AAA). Rearing black weevil with Litete cultivar has shown better insect growth larvae expressed from most of parameters such as larvae number (31), adults emergency frequency (26.6), larvae's mortality rate (14.1%) and post-larvae development cycle (30 to 34 days) compared to Yangambi (9.3 larvae). Therefore, black weevil showed good response on plantains cultivars. Sex ratio (male: female) was either for among plantains cultivars but highly influenced from Yangambi Km5 with 1.8:1. Yangambi Km5 antibiosis showed high larvae mortality rate of 63.67%, weak emergency rate (28) and long post-larvae development of 50 days. This shows that the cultivar 'Litete' was the most susceptible to weevils.
Keys words: banana, Musa cultivars, weevils, emergency, development cycleLe développement du charançon noir (Cosmopolites sordidus Germar) des bananiers et bananiers plantains (Musa sp.) a été évalué sur quatre cultivars: Libanga likale (Musa AAB), Litete (Musa AAB), Lokusu (Musa AAB) et Yangambi Km5 (Musa AAA). Le charançon noir élevé sur le cultivar Litete a montré une meilleure croissance exprimée dans la plupart des paramètres comme le nombre de larves (31), la fréquence d’émergence des adultes (26.6), le taux de mortalité larvaire (14,1%) ainsi que la longueur du cycle de développement post-larvaire (30 à 34 jours). Le charançon noir s’y développe plus vite et plus nombreux. Le ratio sexuel est similaire chez les cultivars de bananiers plantains mais fortement influencé chez Yangambi Km5 où il est de 1,8 :1. L’antibiose de Yangambi Km5 se manifeste par un taux de mortalité larvaire élevé de 62.8%, faible taux d’émergence des adultes (9.3) et un cycle de développement post-larvaire plus long (50 jours) et un ratio sexuel déséquilibré. Ceci montre que le cultivar Litete est le plus sensible aux charançons par rapport aux cultivars étudiés.
MOTS-CLEFS: bananier, Musa, cultivars, charançons, émergence, cycle de développemen
Tuning Pt characteristics on Pt/C catalyst for aqueous-phase reforming of biomass-derived oxygenates to bio-H-2
Pt/C catalysts with varied Pt sizes and distributions were investigated for aqueous-phase reforming (APR) of ethylene glycol (EG) to H2. APR experiments were performed on a continuous-flow fixed bed reactor with a catalyst loading of 1 g and EG feeding of 120 mL h−1 at 225 °C and 35 bar for 7 h. The fresh and used Pt/C catalysts were characterized by XRF, BET, CO chemisorption, TEM, XTEM, and XPS. Catalyst preparation protocols changed Pt characteristics on Pt/C catalysts, leading to a distinguishable H2 production. The rates for EG conversion and H2 production increased linearly with mean Pt size (3–11 nm), while having a volcano relationship with the mean size of agglomerated Pt particles (17–30 nm). Pt with concentrated Pt particles on surface of Pt/C catalysts was more preferable for APR of EG than the homogeneously distributed in catalysts. Optimal performance was obtained over a Pt/C-PR catalyst, which was prepared by precipitation method, showing a superb turnover frequency of 248 molH2 molPt−1 min−1 for H2 production from EG in APR. Besides, Pt/C catalysts also showed excellent stability. These results have shown the promise of Pt/C catalyst for APR of EG, which can be extended for bio-H2 production via APR of biomass-derived oxygenates in waste streams
Interaction of Aspirin (Acetylsalicylic Acid) with Lipid Membranes
We studied the interaction of Aspirin (acetylsalicylic acid) with lipid membranes using x-ray diffraction for bilayers containing up to 50 mol% of aspirin. From 2D x-ray intensity maps that cover large areas of reciprocal space we determined the position of the ASA molecules in the phospholipid bilayers and the molecular arrangement of the molecules in the plane of the membranes. We present direct experimental evidence that ASA molecules participate in saturated lipid bilayers of DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) and preferably reside in the head group region of the membrane. Up to 50 mol% ASA molecules can be dissolved in this type of bilayer before the lateral membrane organization is disturbed and the membranes are found to form an ordered, 2D crystal-like structure. Furthermore, ASA and cholesterol were found to co-exist in saturated lipid bilayers, with the ASA molecules residing in the head group region and the cholesterol molecules participating in the hydrophobic membrane core
A Comprehensive Expression Profile of MicroRNAs in Porcine Pituitary
MicroRNAs (miRNAs) are an abundant class of small RNAs that regulate expressions of most genes. miRNAs play important roles in the pituitary, the “master” endocrine organ.However, we still don't know which role miRNAs play in the development of pituitary tissue or how much they contribute to the pituitary function. By applying a combination of microarray analysis and Solexa sequencing, we detected a total of 450 miRNAs in the porcine pituitary. Verification with RT-PCR showed a high degree of confidence for the obtained data. According to the current miRBase release17.0, the detected miRNAs included 169 known porcine miRNAs, 163 conserved miRNAs not yet identified in the pig, and 12 potentially new miRNAs not yet identified in any species, three of which were revealed using Northern blot. The pituitary might contain about 80.17% miRNA types belonging to the animal. Analysis of 10 highly expressed miRNAs with the Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that the enriched miRNAs were involved not only in the development of the organ but also in a variety of inter-cell and inner cell processes or pathways that are involved in the function of the organ
Production of Transgenic Pigs Mediated by Pseudotyped Lentivirus and Sperm
Sperm-mediated gene transfer can be a very efficient method to produce transgenic pigs, however, the results from different laboratories had not been widely repeated. Genomic integration of transgene by injection of pseudotyped lentivirus to the perivitelline space has been proved to be a reliable route to generate transgenic animals. To test whether transgene in the lentivirus can be delivered by sperm, we studied incubation of pseudotyped lentiviruses and sperm before insemination. After incubation with pig spermatozoa, 62±3 lentiviral particles were detected per 100 sperm cells using quantitative real-time RT-PCR. The association of lentivirus with sperm was further confirmed by electron microscopy. The sperm incubated with lentiviral particles were artificially inseminated into pigs. Of the 59 piglets born from inseminated 5 sows, 6 piglets (10.17%) carried the transgene based on the PCR identification. Foreign gene and EGFP was successfully detected in ear tissue biopsies from two PCR-positive pigs, revealed via in situ hybridization and immunohistochemistry. Offspring of one PCR-positive boar with normal sows showed PCR-positive. Two PCR-positive founders and offsprings of PCR-positive boar were further identified by Southern-blot analysis, out of which the two founders and two offsprings were positive in Southern blotting, strongly indicating integration of foreign gene into genome. The results indicate that incubation of sperm with pseudotyped lentiviruses can incorporated with sperm-mediated gene transfer to produce transgenic pigs with improved efficiency
Chironomid communities from subalpine peatlands in subtropical China as indicators of environmental change
The composition of Chironomidae communities and the ecological significance of such assemblages in peatlands have received little attention, especially in subtropical alpine regions. We report on the spatial distribution of subfossil chironomids and environmental controls on the insects in three subalpine peatlands from subtropical, central China. We found 44 genera and 62 morphotypes in 41 surficial peat samples from three peatlands in subtropical China. The taxa are different from those found in shallow freshwater lakes in the same region, as terrestrial/semi-terrestrial taxa are common in the peatland chironomid communities. Dissimilarities were observed among the three investigated peatlands, and spatially heterogeneous microhabitats also showed notable differences in particular species abundances, even within the same peatland. Important taxa that are associated with specific peatlands, and/or illustrate within-peatland community differences, include Tanytarsus pallidicornis-type2, which is related to lower conductivity, and Neozavrelia, which is associated with greater redox potential and pH. Multivariate statistical analysis revealed significant relationships between chironomid community composition and three environmental factors (conductivity, redox potential and pH). Anthropogenic influences and autogenic processes in peatlands likely modify the biotic communities, either through direct or indirect changes in peatland hydrology and chemistry. Low chironomid concentrations and diversity in Erxianyan Peatland may reflect ecological degradation caused by intense human activities, including the harvest of Sphagnum. This study provides information about subtropical peatland biodiversity and illustrates the utility of subfossil chironomids as proxies for past hydro-chemical changes in peatlands
Adipose depots differ in cellularity, adipokines produced, gene expression, and cell systems
The race to manage the health concerns related to excess fat deposition has spawned a proliferation of clinical and basic research efforts to understand variables including dietary uptake, metabolism, and lipid deposition by adipocytes. A full appreciation of these variables must also include a depot-specific understanding of content and location in order to elucidate mechanisms governing cellular development and regulation of fat deposition. Because adipose tissue depots contain various cell types, differences in the cellularity among and within adipose depots are presently being documented to ascertain functional differences. This has led to the possibility of there being, within any one adipose depot, cellular distinctions that essentially result in adipose depots within depots. The papers comprising this issue will underscore numerous differences in cellularity (development, histogenesis, growth, metabolic function, regulation) of different adipose depots. Such information is useful in deciphering adipose depot involvement both in normal physiology and in pathology. Obesity, diabetes, metabolic syndrome, carcass composition of meat animals, performance of elite athletes, physiology/pathophysiology of aging, and numerous other diseases might be altered with a greater understanding of adipose depots and the cells that comprise them-including stem cells-during initial development and subsequent periods of normal/abnormal growth into senescence. Once thought to be dormant and innocuous, the adipocyte is emerging as a dynamic and influential cell and research will continue to identify complex physiologic regulation of processes involved in adipose depot physiology
A Survey on Personalized TV and NGN Services through Context-Awareness
International audienceThe advances in IPTV (Internet Protocol Television) technology enable a new user-centric and interactive TV model, in which context-awareness is promising in making the user's interaction with the TV dynamic and transparent. Our research interest is how to achieve TV service personalization applying context-awareness to the NGN IPTV architecture. In this article we present the different existing contributions that employ context-awareness to allow interactive services. Some of these contributions directly focus on TV, while others are proposed for specific NGN services. We present a technical analysis for these solutions and give some guidelines for future deployment of personalized IPTV services