A Review of Current Methodologies for Regional Evapotranspiration Estimation from Remotely Sensed Data

An overview of the commonly applied evapotranspiration (ET) models using remotely sensed data is given to provide insight into the estimation of ET on a regional scale from satellite data. Generally, these models vary greatly in inputs, main assumptions and accuracy of results, etc. Besides the generally used remotely sensed multi-spectral data from visible to thermal infrared bands, most remotely sensed ET models, from simplified equations models to the more complex physically based two-source energy balance models, must rely to a certain degree on ground-based auxiliary measurements in order to derive the turbulent heat fluxes on a regional scale. We discuss the main inputs, assumptions, theories, advantages and drawbacks of each model. Moreover, approaches to the extrapolation of instantaneous ET to the daily values are also briefly presented. In the final part, both associated problems and future trends regarding these remotely sensed ET models were analyzed to objectively show the limitations and promising aspects of the estimation of regional ET based on remotely sensed data and ground-based measurements

Predicting the distribution of Chilo partellus (Swinhoe) and its Parasitoid Cotesia flavipes Cameron in Ethiopia using correlation, step-wise regression and geographic information systems

The recent development of geographic information systems (GIS) provides new avenues for analysing spatial patterns in insect populations. Field survey data, along with GIS and statistical models were used to predict the distribution of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) and Cotesia flavipes Cameron (Hymenoptera: Braconidae) in Ethiopia. The results obtained suggested that the distributions of Ch. partellus and Co. flavipes were affected by rainfall and temperature. The predicted distributions of Ch. partellus and Co. flavipes were similar. Validation of predicted values is discussed. RÉSUMÉ Le récent développement du système d'information géographique (GIS) ouvre de nouvelles perspectives pour l'analyse de la distribution spatiale des populations d'insectes. Les données obtenues lors d'enquêtes de terrain, combinées à des modèles GIS et statistiques on été utilisées pour prédire la distribution de Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) et de Cotesia flavipes Cameron (Hymenoptera: Braconidae) en Ethiopie. Les résultats obtenus suggèrent que la distribution de Ch. partellus et de Co. flavipes est influencée par la pluviométrie et la température. Les distributions prédites de Ch. partellus et de Co. flavipes sont similaires. La validation des valeurs prédites est discutée

Will Cotesia flavipes drive its African homologue, Cotesia sesamiae, to extinction

This paper addresses the competitive interaction between Cotesia sesamiae, a gregarious larval endoparasitoid that is native to Africa, and Cotesia flavipes, an introduced parasitoid from southern Pakistan which has recently been established in East Africa for biological control of the exotic stemborer, Chilo partellus. The two parasitoids are morphologically similar, and they both attack medium-sized to large larval stages of gramineous lepidopteran stemborers. Based on previous work which suggested that Cotesia flavipes was competitively superior to Co. sesamiae, we speculated that Co. sesamiae may be locally extirpated in some areas of Africa. However, evidence from the field does not support this prediction. Recent field surveys in areas where both parasitoids occur, revealed that Co. sesamiae was still present, and densities were not declining. The interaction of the two parasitoids, as well as the influence of this interaction on host regulation, are discussed. RÉSUMÉ Cet article discute de la compétition entre Cotesia sesamiae et Cotesia flavipes deux parasitoïdes internes et grégaires, morphologiquement semblables. Ils attaquent les larves de foreurs de tige de graminés. Le premier est endémique á l'Afrique et le second a été importé du sud Pakistan dans la cadre de la lutte biologique classique en Afrique de l'est contre, Chilo partellus, un foreur de tige de céréales originaire d'Asie. Sur la base des travaux antérieurs qui ont montré que Co. flavipes était competitivement supérieur á Co. sesamiae, nous avions spéculé que Cotesia sesamiae pourrait eventuellement être éliminé dans certaines régions d'Afrique. Toutefois, des données récentes de terrain ne sont pas en accord avec cette hypothèse. Des enquêtes récentes dans les régions où les deux parasitoïdes existent ont montré que Co. sesamiae est toujours présent et que ses densités ne décroissent pas. Les interactions entre les deux parasitoïdes et l'effet de cette interaction sur la régulation de l'hôte sont discutés

Expression and Significance of Nrf2 and Its Target Genes in Pulmonary Adenocarcinoma A549 Cells Resistant to Cisplatin

Background and objective Nuclear factor erythroid-2 related factor 2 (Nrf2) is a key transcription factor in oxidation-reduction reaction. It has been proved that Nrf2 is relevant to cisplatin-resistance in ovarian cancer cells. Up to now, little is know whether Nrf2 and it’s signal patheways play an important role in cisplatin-resistance in pulmonary adenocarcinoma cells or not. The aim of this study is to explore the expression levels of transcription factor Nrf2 and its target genes in A549 cells which are resistance to cisplatin and reveal the mechanism behind it. Methods A549/DDP and A549 were cultured in vitro. MTT was used to detect the drug resistance index of A549/DDP cells. Real-time PCR was used to evaluate the expression of transcription factor Nrf2 and its target genes mRNA. Results The drug resistance index of A549/DDP was 12.12, and its Keap1, Nrf2, NQO1, GSTP1, GCL, HO-1, MRP4 mRNA expressions were all significantly increased compared with A549 (P<0.01). On the other hand, MRP1, MRP2, MRP3 showd the crosscurrent (P<0.01). Conclusion It proves that the transcription factor Nrf2 and it’s signal pathways are closely related with drug resistance of tumors. Moreover, this provides a new direction to reverse drug resistance and have significance to avoid and overcome drug resistance of tumor