The Hertz Corporation

About: The Hertz Corporation is a based out in . It is known for research contribution in the topics: Population & Soil water. The organization has 9562 authors who have published 11044 publications receiving 447929 citations. The organization is also known as: Hertz Rental Car & Hertz Rent-a-Car.

Unusual response of DDT-resistant houseflies to carbinol analogues of DDT

Abstract: THE toxic action of DDT is thought to be caused by complex formation between the insecticide and nerve protein, a mechanism consistent with the well known phenomenon of negative correlation between insect mortality and temperature1. We present here evidence which indicates that some carbinols which are close analogues of DDT may have a different mode of action. These compounds elicit very different symptoms of poisoning, and none of the major mechanisms of resistance to DDT in the housefly confers significant resistance to these compounds.

Acute Paralysis Virus Isolates from Honeybee Colonies Infested with Varroa Jacobsoni

Abstract: SummaryLarge amounts of acute paralysis virus (APV) were extracted from dead, field-collected samples of European honeybees (Apis mellifera) from Russia and German Federal Republic. Virus isolates were compared to the British type strain. Particles of the three isolates were physically indistinguishable and closely related serologically, and each produced three well-defined protein bands of apparently identical mol wt on SDS Polyacrylamide gels. In Britain APV has never been found to be associated with mortality in nature. In both Russia and Germany the occurrence of APV in dead field bees and brood was associated with infestation of the colonies by the mite Varroa jacobsoni. The possible role of the mite in APV infection of honeybees is discussed.

Nuclear differentiation in the pollen grain.

Abstract: THE satisfactory differentiation of the pollen grain is necessary for its effective life, and therefore directly bears on all breeding experiments with flowering plants. Moreover it is under a genetic control of a most complex kind, derived partly from the diploid parent and partly from the haploid cell itself; where it is the most sensitive indicator of the effects of segregation. For these various reasons a precise understanding of the physiology of its development is needed by the plant breeder. A wealth of evidence has accumulated in support of the belief that nuclear differentiation in the pollen grain of Angiosperms is dependent on polarity of development. The most notable work in this direction has been done by Sax (i), Sax and Husted (1936) and Geitler Notwithstanding the excellence of this work, some of the underlying principles have remained obscure. In the present work, the initial observations were connected with an anomalous behaviour found in dwarf pollen grains of a single clone of Tradescantia bracteata. From information so gained, and by comparison with other material, it is believed that a plausible explanation for nuclear differentiation has been provided. In order that the problem should be seen in clear perspective, a review of the previous relevant literature is included.