Mountains are a source of water for downstream areas; thus, it is important to understand the storage and discharge characteristics of steep mountain catchments. Nested catchment studies have indicated that the relation between catchment area and specific discharge during baseflow can represent mesoscale storage and discharge characteristics, but this is poorly understood. We found that baseflow-specific discharge increased with catchment size in the headwater of the Arakawa River and identified the processes responsible for this spatial pattern. Synoptic discharge measurements obtained in catchment areas of 0.05 to 93.58 km 2 showed that specific discharge increased more than threefold with increasing drainage area. Analyses of the spatial variation in precipitation, hydrographs from three continuous gauging stations, and isotopic tracers implied that in this catchment, considerable amounts of water infiltrated in bedrock on hillslopes and did not discharge into small streams, but instead fed surface flow into a larger downstream catchment. A review of previous nested studies demonstrated three spatial patterns for specific discharge: Specific discharge may increase or decrease with catchment area, or it may be independent of area. An increase in specific discharge with area was observed only in catchments with permeable bedrock, which implies that such an increase is a useful indicator of the importance of the bedrock flow path to mountain watershed storage. The pattern of relationships between catchment area and specific discharge can be used to assess the storage and discharge properties of mesoscale catchments when the processes driving each pattern have been clarified.
Plum pox virus (PPV) is transmitted by infected buds and aphids. It is important to analyze the outbreak trends and viruliferous rate of aphids in areas where the occurrence of PPV is reported, so as to develop strategies for disease control. Between April 2011 and December 2012, yellow insect-trapping adhesive plates were placed for 2 days at a time each week in an area where PPV is occurring in Japan. Outbreak trends were analyzed based on the trapped alate aphid samples, and up to 50 of them were tested per week to identify species and determine the rate of viruliferous specimens. Although the number of aphids varied according to survey year, three peaks were noticeable in each year. Based on the sequence data for the mitochondrial cytochrome c oxidase I region, approximately 40 different species of aphid were trapped in both years. Of the five dominant species of aphids identified during the 2 years, Aphis spiraecola was trapped in large numbers. PPV-positive aphids were higher in fall onward, when the total number of trapped aphids decreased, than in spring and summer, when a larger number of aphids was caught. PPV transmission tests using the most abundant species revealed that A. spiraecola, A. craccivora, A. gossypii, and Rhopalosiphum maidis were transmitters, although A. spiraecola is likely of epidemiological significance.
The generation of 3-azidoarynes from o-iodoaryl triflate-type precursors was achieved using a silylmethyl Grignard reagent as the activator. The azido group served to control the regioselectivity of the reaction of 3-azidoarynes with arynophiles. The remaining azido group in the adduct also served as a transformable functional group, enabling further derivatization to various nitrogen-containing compounds.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.