Maximal Ergodic Inequalities for Banach Function Spaces

We analyse the Transfer Principle, which is used to generate weak type maximal inequalities for ergodic operators, and extend it to the general case of $\sigma$-compact locally compact Hausdorff groups acting measure-preservingly on $\sigma$-finite measure spaces. We show how the techniques developed here generate various weak type maximal inequalities on different Banach function spaces, and how the properties of these function spaces influence the weak type inequalities that can be obtained. Finally, we demonstrate how the techniques developed imply almost sure pointwise convergence of a wide class of ergodic averages.Comment: 46 pages. The former Lemma 4.7 and Theorem 4.8 (which had a small gap in the proof) is replaced by Theorem 4.7. This change affects the latter part of section

Integrating functional diversity, food web processes, and biogeochemical carbon fluxes into a conceptual approach for modeling the upper ocean in a high-CO2 world

Marine food webs influence climate by channeling carbon below the permanent pycnocline, where it can be sequestered. Because most of the organic matter exported from the euphotic zone is remineralized within the "upper ocean" (i.e., the water column above the depth of sequestration), the resulting CO2 would potentially return to the atmosphere on decadal timescales. Thus ocean-climate models must consider the cycling of carbon within and from the upper ocean down to the depth of sequestration, instead of only to the base of the euphotic zone. Climate-related changes in the upper ocean will influence the diversity and functioning of plankton functional types. In order to predict the interactions between the changing climate and the ocean's biology, relevant models must take into account the roles of functional biodiversity and pelagic ecosystem functioning in determining the biogeochemical fluxes of carbon. We propose the development of a class of models that consider the interactions, in the upper ocean, of functional types of plankton organisms (e.g., phytoplankton, heterotrophic bacteria, microzooplankton, large zooplankton, and microphagous macrozooplankton), food web processes that affect organic matter (e.g., synthesis, transformation, and remineralization), and biogeochemical carbon fluxes (e.g., photosynthesis, calcification, respiration, and deep transfer). Herein we develop a framework for this class of models, and we use it to make preliminary predictions for the upper ocean in a high-CO2 world, without and with iron fertilization. Finally, we suggest a general approach for implementing our proposed class of models

Projected Red Pine Yields from Aldrin-Treated and Untreated Stands Damaged by White Grubs and Other Agents

(excerpt) Young red pines, Pinus resinosa Ait., during the first few years after planting in the Lake States, are vulnerable to several injurious agents, including white grubs, the larvae of May beetles, Phyllophaga spp. (Kittredge, 1929; Craighead, 1950). The pesticide aldrin3 has frequently been applied at planting time to protect seedlings from white grubs. More than 12,000 acres of national forest land were treated with aldrin from 1960 to 1967 in the Lake States; almost 10,000 of these were on the Hiawatha National Forest (Fowler, 1973)

White Grub Populations, Phyllophaga Spp., in Relation to Damaged Red Pine Seedlings in Michigan and Wisconsin Plantations (Coleoptera: Scarabaeidae)

Excerpt: White grubs (Coleoptera, Scarabaeidae), the larvae of May and related beetles, are destructive pests in some young pine plantations in the Lake States Region. They live in the soil and feed on roots of trees and other vegetation. Larvae chew off the smaller and girdle the ldrger roots of pine seedlings, and consequently reduce growth, weaken, and kill the seedlings. Recommendations against planti.ng or for control measures have been made for grub population densities ranging from 4.4/ft2, 2.0/ft.3, 2.0/ft.\u27, down to 0.5 grubs/ft2 of soil surface (Stone and Schwardt, 1943; Rudolf, 1950; Speers and Schmiege, 1961 ; Shenefelt et al., 1954). A study was carried out to accurately assess or predict grub-caused mortality and damage to seedlings from a given grub population density. This information is necessary for making control recommendations

Decline in Youth Participation in Canada in the 1990s: Structural or Cyclical?

Of the three major age groups, youth (aged 15-24), experienced the largest fall in labour force participation and accounted for the lion’s share of the aggregate decline. Consequently, an understanding of the factors behind this development is essential to an overall understanding of the fall in labour force participation in the 1990s in Canada. In the fifth and final article in the symposium, Richard Archambault and Louis Grignon examine the causes of this large fall in youth labour force participation in Canada in the 1990s. They disaggregate the youth participation rate into three components: the student participation rate, the non-student participation rate, and the school enrolment rate. The aggregate youth rate is the sum of the student and non-student rates weighted by their respective shares of the population (the enrolment rate for students). Such an approach makes it possible to take account of behavioural differences between students and non-students and to treat the enrolment rate as a phenomenon to be explained rather than a determinant of the participation rate. All three variables are modelled as a function of a cyclical variable and a number of structural variables - the real wage, the relative minimum wage, employment insurance, social assistance, and a time trend. The results show the importance of economic conditions and the modest effect of public policy programs on the decision to participate in the labour market and go to school. Based on the equations estimated for the 1976-96 period, a dynamic simulation was conducted over the 1990-96 period to account for the impact of the variables on the student and non-student participation rates and enrolment rate. According to the equations estimated for the 15-24 age group, the cyclical variable accounts for about one half of the decline in the youth participation rate between 1990 and 1996, two thirds of the decline in the student participation rate, and about one third of the fall in both the non-student participation rate and rise in the enrolment rate. The remaining decline in the two participation rates and rise in the enrolment rate are not to any significant degree explained by the four structural variables, but rather are either captured by the time trend or not explained at all. Given these results, the authors conclude that we have a poor understanding of the non-cyclical forces that account for up to one half of the decline in youth labour force participation in the 1990s.Canada, Labour Force Participation, Labor Force Participation, Participation Rate, Labour Force Participation Rate, Labor Force Participation Rate, Age Structure, Age, Youth, Teenage, Young Adult, Student, Enrolment Rate, Enrolment, Enrollment Rate, Enrollment