Variegation of comet 67P/Churyumov-Gerasimenko in regions showing activity

Aims. We carried out an investigation of the surface variegation of comet 67P/Churyumov-Gerasimenko, the detection of regions showing activity, the determination of active and inactive surface regions of the comet with spectral methods, and the detection of fallback material. Methods. We analyzed multispectral data generated with Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) narrow angle camera (NAC) observations via spectral techniques, reflectance ratios, and spectral slopes in order to study active regions. We applied clustering analysis to the results of the reflectance ratios, and introduced the new technique of activity thresholds to detect areas potentially enriched in volatiles. Results. Local color inhomogeneities are detected over the investigated surface regions. Active regions, such as Hapi, the active pits of Seth and Ma'at, the clustered and isolated bright features in Imhotep, the alcoves in Seth and Ma'at, and the large alcove in Anuket, have bluer spectra than the overall surface. The spectra generated with OSIRIS NAC observations are dominated by cometary emissions of around 700 nm to 750 nm as a result of the coma between the comet's surface and the camera. One of the two isolated bright features in the Imhotep region displays an absorption band of around 700 nm, which probably indicates the existence of hydrated silicates. An absorption band with a center between 800-900 nm is tentatively observed in some regions of the nucleus surface. This absorption band can be explained by the crystal field absorption of Fe2+, which is a common spectral feature seen in silicates.

Economic integration, location of industries, and frontier regions : evidence from Cambodia

We examine changes in the location of economic activity in Cambodia between 1998 and 2008 in terms of employment growth. During this period, Cambodia joined ASEAN and increased trade with neighboring countries. Drawing on the predictions of the new economic geography, we focus on frontier regions such as border regions and international port cities. We examine the changing state of manufacturing in Cambodia from its initial concentration in Greater Phnom Penh to its growth in the frontier regions. The results suggest that economic integration and concomitant trade linkages may lead to the industrial development of frontier regions as well as the metropolitan areas in Cambodia.

Production sharing, demand spillovers and CO2 emissions : the case of Chinese regions in GVCs

This study adopts the perspective of demand spillovers to provide new insights regarding Chinese domestic-regions' production position in global value chains and their associated CO2 emissions. To this end, we constructed a new type of World Input-Output Database in which China's domestic interregional input-output table for 2007 is endogenously embedded. Then, the pattern of China's regional demand spillovers across both domestic regions and countries are revealed by employing this new database. These results were further connected to endowments theory, which help to make sense of the empirical results. It is found that China's regions locate relatively upstream in GVCs, and had CO2 emissions in net exports, which were entirely predicted by the environmental extended HOV model. Our study points to micro policy instruments to combat climate change, for example, the tax reform for energy inputs that helps to change the production pattern thus has impact on trade pattern and so forth.

Rice flows across regions in Madagascar

Although spatial disintegration of rice markets in Madagascar has been well documented, little is known about actual rice flows across regions. Using weekly collected unique data from rice markets in 22 regional capital cities for one year, this study explores the physical distribution of rice in Madagascar and reveals that rice flows from sufficient regions to deficit regions, along with geographical proximity, have positive effects on rice flow. In contrast, season factors, such as harvest/non-harvest periods and weather conditions have a negligible effect on rice flow. These findings suggest that rice flows generally follow a rational pattern despite the fact that market indicators indicate that rice trade across regions is underdeveloped.