Leaflet / Field Museum of Natural History, Dept. of Anthropology.

no.4(1922)

Type fossil Coelenterata (except corals) in Field Museum of Natural History / Gerald Glenn Forney --, Matthew H. Nitecki --, and Daniel T. Jenkins --.

v.37:no.4(1977)

Culture areas of Nigeria, by Wilfrid D. Hambly -- Frederick H. Rawson-Field Museum Ethnological Expedition to West Africa, 1929-30. 68 plates in photogravure and 1 map.

v.21:no.3(1935)

Catalogue of type and referred specimens of fossil corals in Field Museum of Natural History / [by] Phyllis N. Windle --, Ronald M. Augustynek -- [and] Matthew H. Nitecki --. [Patricia M. Williams, -- editor --]

v.32(1973)

Bulletin / Field Museum of Natural History.

v. 42 (1971)

Bulletin / Field Museum of Natural History.

v. 41 (1970)

Ecological economics

Ecological economics is a recently developed field, which sees the economy as a subsystem of a larger finite global ecosystem. Ecological economists question the sustainability of the economy because of its environmental impacts and its material and energy requirements, and also because of the growth of population. Attempts at assigning money values to environmental services and losses, and attempts at correcting macroeconomic accounting, are part of ecological economics, but its main thrust is rather in developing physical indicators and indexes of sustainability. Ecological economists also work on the relations between property rights and resource management, they model the interactions between the economy and the environment, they study ecological distribution conflicts, they use management tools such as integrated environmental assessment and multi-criteria decision aids, and they propose new instruments of environmental policy.

Field Museum of Natural History bulletin.

v. 44 (1973)

Publication. Field Columbian Museum.

v.2:no.1(1900)

Infinite index subgroups and finiteness properties of intersections of geometrically finite groups

We explore which types of finiteness properties are possible for intersections of geometrically finite groups of isometries in negatively curved symmetric rank one spaces. Our main tool is a twist construction which takes as input a geometrically finite group containing a normal subgroup of infinite index with given finiteness properties and infinite Abelian quotient, and produces a pair of geometrically finite groups whose intersection is isomorphic to the normal subgroup.

New field observations on the competitive displacement between two species of planorbid snails inhabiting Northeastern Brasil

Observations reported in the present paper have shown that Biomphalaria glabrata is being gradually displaced by B. straminea in coastal areas of two counties on the state of Pernambuco, Brazil, confirming former observations made in the same region.

What is paragonimus rudis (diesing, 1850)?: report on a field study in Mato Grosso, Brazil

Paragonimus rudis was found in the lungs of a giant otter Lutra (pteronura) brasiliensis by Natterer in 1828, who dissected the animal in the former capital Mato Grosso (=Vila Bela), Brazil. The flukes were described by Diesing in 1850, and redescribed by Braun in 1901. Both descriptions do not allow to identify the species. Therefore, P. rudis must be regarded a "nomen nudum". Because its rediscovery is desirable with regard to historical reasons and nomenclatoric questions, a field study was performed in Mato Grosso in 1980. Of 354 freshwater crabs from 24 localities collected and examined for parasitic infections, about 25% were found to be infected with 7kinds of trematode larvae, which differed distincly from Paragonimus-metacercariae. The question, whether P. rudis or other lung fluke species do not seem to occur or cannot be found any longer in the area investigated by us, is discussed.

Orthogonal systems in finite grahps

To a finite graph there corresponds a free partially commutative group: with the given graph as commutation graph. In this paper we construct an orthogonality theory for graphs and their corresponding free partially commutative groups. The theory developed here provides tools for the study of the structure of partially commutative groups, their universal theory and automorphism groups. In particular the theory is applied in this paper to the centraliser lattice of such groups.

Dispositius nanoelectrònics a freqüències de THz : estudi de la propagació electromagnètica en les connexions

Per a altes freqüències, les connexions poden tenir un paper rellevant. Atès que la velocitat de propagació dels senyals electromagnètics, c, en el cable no és infinita, el voltatge i el corrent al llarg del cable varien amb el temps. Per tant, amb l’objectiu de reproduir el comportament elèctric de dispositius nanoelectrònics a freqüències de THz, en aquest treball hem estudiat la regió activa del dispositiu nanoelectrònic i les seves connexions, en un sistema global complex. Per a aquest estudi hem utilitzat un nou concepte de dispositiu anomenat Driven Tunneling Device (DTD). Per a les connexions, hem plantejat el problema a partir de tot el conjunt de les equacions de Maxwell, ja que per a les freqüències i longituds de cable considerats, la contribució del camp magnètic és també important. En particular, hem suposat que la propagació que és dóna en el cable és una propagació transversal electromagnètica (TEM). Un cop definit el problema hem desenvolupat un programa en llenguatge FORTRAN que amb l'algoritme de diferències finites soluciona el sistema global. La solució del sistema global s'ha aplicat a una configuració particular de DTD com a multiplicador de freqüència per tal de discutir quins paràmetres de les connexions permet maximitzar la potència real que pot donar el DTD.