photosynthesis (1). Total radioactivity fixed per leaf was unchanged by the two-hour treatment with gibberellic acid; typical results are shown in table I. Similar results were also obtained in one experiment with Chlorella pyrenoidosa. Examination of autoradiograms of the chromatograms of extracts from the oats, barley, and peas showed no significant differences in the distribution of C'4 amon...

BACKGROUND Government-administered adulticiding is frequently conducted in response to dengue transmission worldwide. Anecdotal evidence suggests that spraying may create a "false sense of security" for residents. Our objective was to determine if there was an association between residents' reporting outdoor spatial insecticide spraying as way to prevent dengue transmission and both their repor...

This article reports the results of an econometric evaluation of the effects of Plan Colombia, the largest US aid package ever received by a country in the western hemisphere. We assess how the aerial spraying of illegal crops affects both the size of the land cultivated with coca bushes as well as the dynamics of localized violence in the context of Colombia’s armed conflict. In particular, we...

Autonomous selective spraying could be a way for agriculture to reduce production costs, save resources, protect the environment and help to fulfill specific pesticide regulations. The objective of this paper was to investigate the use of a low-cost sonar sensor for autonomous selective spraying of single plants. For this, a belt driven autonomous robot was used with an attached 3-axes frame wi...

We measured airborne exposures to the biological insecticide Bacillus thuringiensis var. kurstaki (Btk) during an aerial spray program to eradicate gypsy moths on the west coast of Canada. We aimed to determine whether staying indoors during spraying reduced exposures, to determine the rate of temporal decay of airborne concentrations, and to determine whether drift occurred outside the spray z...

Indoor residual spraying with DDT was the principle method by which malaria transmission was eradicated or greatly reduced in many countries between the late 1940s and 1970s. Since then, decreasing use of DDT has been associated with a resurgence of malaria in India, Sri Lanka, former Soviet Central Asia, Zanzibar, Venezuela and several other Latin American countries. In India and Zanzibar, DDT...

In the previous paper of this series, the retention characteristics of 4-methyl sterols were investigated with a view for establishing a systematic relationship between the structure of sterols and their gas chromatographic characteristics. The present report deals an extended study on 6methyl sterols prepared from cholesterol. The retention data for five 6-methyl sterols and for their derivati...

Povzetek. Sodobne organizacije se spreminjajo zelo pogosto. Spremembe se poskuša izvesti hitro in učinkovito. Spremembe pogosto vključujejo spremembe IS zaradi njegovega pomena v organizacijah. Odpor do sprememb spada med ključne dejavnike uspeha večjih projektov in programov IT. Obvladovanje odpora ne pomaga organizacijam zgolj izvesti spremembe hitreje in učinkoviteje, temveč je hkrati tudi p...

Current EPA emission factors (AP42) for styrene emissions from the production of polyester-resin-reinforced plastic products represent a composite of spraying and post-spraying emissions (from curing molds) from shower stall/bathtub manufacturing plants that use compressed-air-powered spray guns to apply catalyzed styrene resins to prepared molds. Because each step of manufacture (gel coating, ...

Some day it may be said that the air age in insect control arrived with the discovery of the unusual values of DDT during the Second World War. In the two preceding decades, the application of insecticides by airplane had been tried against various pests, but the method was not used extensively except over cotton fields. Its advantages were recognized—large acreages could be covered quickly wit...