Studies of Birds and Mammals in the Baird and Schwatka Mountains, Alaska

In 1963 a joint University of Alaska-Smithsonian Institution crew worked at five locations in the Baird and Schwatka mountains in northwestern Alaska, conducting an ecological reconnaissance and faunal and floral inventory. Standard methods of observation and collection were used. Camps in the Kobuk drainage were located in the Redstone River valley and at Walker Lake, both on the margin of the taiga. The Noatak valley was represented by one camp each in the lower, middle, and upper reaches of the river, all in tundra. A summary of pre-1963 ornithological work in the region is presented. Significant records of distribution and/or breeding were obtained for the following birds: Podiceps grisegena, Anas platyrhynchos, Aythya valisineria, Histrionicus histrionicus, Melanitta perspicillata, Mergus merganser, Aphrizia virgata, Bartramia longicauda, Actitis macularia, Tringa flavipes, Phalaropus fuficarius, Lobipes lobatus, Larus hyperboreus,Xema sabini, Sayornis saya, Nuttalornis borealis, Eremophilia alpestris, Tachycineta thalassina, Riparia riparia, Petrochelidon pyrrhonota, Phylloscopus borealis, Dendroica petechia, Leucosticte tephrocotis, Zonotrichia atricapilla, Calcarius pictus; and the mammal, Spermophilus undulatus. Good series of Cletihrionomys rutilius (350) and Microtus miurus (147) have been deposited in the University of Alaska Museum. Severe doubt has been raised regarding the validity of the standard three-night trap grid for population estimation under wet conditions in arctic areas

Contrasting Views of Complexity and Their Implications For Network-Centric Infrastructures

There exists a widely recognized need to better understand and manage complex “systems of systems,” ranging from biology, ecology, and medicine to network-centric technologies. This is motivating the search for universal laws of highly evolved systems and driving demand for new mathematics and methods that are consistent, integrative, and predictive. However, the theoretical frameworks available today are not merely fragmented but sometimes contradictory and incompatible. We argue that complexity arises in highly evolved biological and technological systems primarily to provide mechanisms to create robustness. However, this complexity itself can be a source of new fragility, leading to “robust yet fragile” tradeoffs in system design. We focus on the role of robustness and architecture in networked infrastructures, and we highlight recent advances in the theory of distributed control driven by network technologies. This view of complexity in highly organized technological and biological systems is fundamentally different from the dominant perspective in the mainstream sciences, which downplays function, constraints, and tradeoffs, and tends to minimize the role of organization and design

All-Orders Singular Emission in Gauge Theories

I present a class of functions unifying all singular limits for the emission of soft or collinear gluons in gauge-theory amplitudes at any order in perturbation theory. Each function is a generalization of the antenna functions of ref. [1]. The helicity-summed interferences these functions are thereby also generalizations to higher orders of the Catani--Seymour dipole factorization function.Comment: 5 pages, 1 figur

Interest rate targets abandoned

Interest rates ; Monetary policy - Japan

Cities and Skills

This paper examines the productivity (and wage) gains from locating in dense, urban environments. We distinguish between three potential explanations of why firms are willing to pay urban workers more: (1) the urban wage premium is spurious and is the result of omitted ability measures, (2) the urban wage premium works because cities enhance productivity and (3) the urban wage premium is the result of faster skill accumulation in cities. Using a combination of standard regressions, individual fixed effects estimation (using migrants) and instrumental variables methods, we find that the urban wage premium does not represent omitted ability bias and it is only in part a level effect to productivity. The bulk of the urban wage premium accrues over time as a result of greater skill accumulation in cities.