The development of tropical depressions within tropical waves over the Atlantic and eastern Pacific is usually preceded by a " surface low along the wave " as if to suggest a hybrid wave-vortex structure in which flow streamlines not only undulate with the waves, but form a closed circulation in the lower troposphere surrounding the low. This 5 structure, equatorward of the easterly jet axis, r...

Given a tropical line L on a tropical surface X, we define its combinatorial position on X to be a certain decorated graph, showing the relative positions of vertices of X on L, and how the vertices of L are positioned on X. We classify all possible combinatorial positions of a tropical line on general smooth tropical surfaces of any degree. This classification allows one to give an upper bound...

We study the tropical lines contained in smooth tropical surfaces in R3. On smooth tropical quadric surfaces we find two one-dimensional families of tropical lines, like in classical algebraic geometry. Unlike the classical case, however, there exist smooth tropical surfaces of any degree with infinitely many tropical lines.

malaria is a major problem in tropical and sub-tropical countries, with high morbidity and mortality. splenectomy makes patients more susceptible to serious bacterial and parasitic infections. we report for the first time in iran a fatal case of plasmodium vivax malaria, confirmed by microscopic and molecu­lar (semi-nested multiplex pcr) tests in a patient who had undergone splenectomy due to h...

Contents 1. Introduction 2. The origin of tropical crops 3. Dissemination of tropical crops outside their centers of origin 4. Tropical agriculture in colonial times 5. Independence and tropical agriculture 6. Tropical food crops 7. Outlook on tropical agriculture 8. Tropical food crops in a globalized economy 9. Historical background 10. Globalization 11. Free trade 12. The starting point 13. ...

The standard view of modern human infectious diseases is that many of them arose during the Neolithic when animals were first domesticated, or afterwards. Here we review recent genetic and molecular clock estimates that point to a much older Paleolithic origin (2.5 million years ago to 10,000 years ago) of some of these diseases. During part of this ancient period our early human ancestors were...

Detection and attribution of past changes in cyclone activity are hampered by biased cyclone records due to changes in observational capabilities. Here we construct an independent record of Atlantic tropical cyclone activity on the basis of storm surge statistics from tide gauges. We demonstrate that the major events in our surge index record can be attributed to landfalling tropical cyclones; ...

Recent years have seen a rapid growth of interest in the history of tropical medicine, sparked by a number of academic and political developments. Imperialism is back on the scholarly agenda, leading us to ask how important empire was to science and medicine, and vice versa. Post-colonial studies raise questions about how the colonies were critical to the constitution or genealogy of science an...

Received Jan 11, 2018 Revised Mar 8, 2018 Accepted Mar 22, 2018 Free-space optical (FSO) links provide high speed point-to-point wireless communication, but its availability can easily be affected by weather conditions. In heavy rainfall regions, FSO links are relatively sensitive to rain. Availability prediction of FSO is indispensable part, especially in tropical areas. In this paper, methods...

Observations of pre-1950 tropical cyclones are sparse due to observational limitations; therefore, the hurricane database HURDAT2 (1851-present) maintained by the National Oceanic and Atmospheric Administration may be incomplete. Here we provide additional documentation for HURDAT2 from historical United States Army fort records (1820-1915) and other archived documents for 28 landfalling tropic...