Impatience and Intergenerational Equity in a Model of Sustainable Growth

We argue that intergenerational neutrality has been prematurely excluded from the dialogue on sustainable growth. By incorporating Burton’s distinction between intragenerational and intergenerational discounting into a model suitable for analyzing sustainability issues, we are able to accommodate some of the underlying concerns. We show that in an economy with a renewable resource, eschewing intergenerational discounting leads to the implication of a sustained growth path, without the necessity of a sustainability constraint. We find that green net national product remains constant along the optimal approach path to golden rule consumption. This avoids the paradox that maximizing sustainable income leads to unsustained consumption and income.Sustainable development, intergenerational equity, intra-generational discounting, renewable resources, green net national product

Sustainable Growth with Environmental Spillovers: A Ramsey-Koopmans Approach

In this paper, we apply the canonical approach of Ramsey, Koopmans, and Diamond to the problem of optimal and intertemporally-equitable growth with a non-renewable resource constraint and show that the solution is sustainable. The model is extended to cases involving environmental amenities and disamenities and renewable resources. The solutions equivalently solve the problem of maximizing net national product adjusted for depreciation in natural capital and environmental effects, which turns out to be both sustainable and constant even without technical change.

Islands of Sustainability in Time and Space

We review the economics perspective on sustainable resource use and sustainable development. Under standard conditions, dynamic efficiency leads to sustainability of renewable resources but not the other way around. For the economic-ecological system as a whole, dynamic efficiency and intergenerational equity similarly lead to sustainability, but ad hoc rules of sustainability may well lead to sacrifices in human welfare. We then address the challenges of extending economic sustainability to space as well as time and discuss the factors leading to optimal islands of preservation regarding renewable resources. Exogenous mandates based on moral imperatives such as self-sufficiency and strong sustainability may result in missed win-win opportunities that could improve both the economy and the environment, as well as increase social welfare across generations.Islands of sustainability, sustainable development, sustainability science, fisheries, forests

Golden Rules For Sustainable Resource Management

This paper presents a simple model of resource management that combines use of a nonrenewable resource, such as oil, with eventual transition to a backstop substitute resource in infinite supply (e.g., solar energy). In the context of this model, we derive golden rules that govern efficiency in both the accumulation of capital and in the extraction of natural resources for use in production. These results supplement the Solow/Hartwick model of maximum consumption in helping to illuminate the notion of sustainable development.

Microfabricated Thin Film Impedance Sensor & AC Impedance Measurements

Thin film microfabrication technique was employed to fabricate a platinum based parallel-electrode structured impedance sensor. Electrochemical impedance spectroscopy (EIS) and equivalent circuit analysis of the small amplitude (±5 mV) AC impedance measurements (frequency range: 1 MHz to 0.1 Hz) at ambient temperature were carried out. Testing media include 0.001 M, 0.01 M, 0.1 M NaCl and KCl solutions, and alumina (∼3 μm) and sand (∼300 μm) particulate layers saturated with NaCl solutions with the thicknesses ranging from 0.6 mm to 8 mm in a testing cell, and the results were used to assess the effect of the thickness of the particulate layer on the conductivity of the testing solution. The calculated resistances were approximately around 20 MΩ, 4 MΩ, and 0.5 MΩ for 0.001 M, 0.01 M, and 0.1 M NaCl solutions, respectively. The presence of the sand particulates increased the impedance dramatically (6 times and 3 times for 0.001 M and 0.1 M NaCl solutions, respectively). A cell constant methodology was also developed to assess the measurement of the bulk conductivity of the electrolyte solution. The cell constant ranged from 1.2 to 0.8 and it decreased with the increase of the solution thickness

Type 1 aqueous alteration in CM carbonaceous chondrites: Implications for the evolution of water-rich asteroids

The CM carbonaceous chondrite meteorites experienced aqueous alteration in the early solar system. They range from mildly altered type 2 to almost completely hydrated type 1 chondrites, and offer a record of geochemical conditions on water‐rich asteroids. We show that CM1 chondrites contain abundant (84–91 vol%) phyllosilicate, plus olivine (4–8 vol%), magnetite (2–3 vol%), Fe‐sulfide (120 °C), although higher water/rock ratios may also have played a role. The modal data provide constraints for interpreting the composition of asteroids and the mineralogy of samples returned from these bodies. We predict that “CM1‐like” asteroids, as has been proposed for Bennu—target for the OSIRIS‐REx mission—will have a high abundance of Mg‐rich phyllosilicates and Fe‐oxides, but be depleted in calcite

Conservation of the role of INNER NO OUTER in development of unitegmic ovules of the Solanaceae despite a divergence in protein function

The P-SlINO::SlINO-GFP transgene continues to be expressed after fertilization during the onset of fruit development. A-C: Ovules from P-SlINO::SlINO-GFP plants. D, E: Ovules from control plants. Images A (confocal) and B (DIC overlaid with GFP channel) show expression in the outer cell layer in an ovule post-anthesis. C-E are images of the surface cells of the integument of ovules taken from 3–4 mm fruits. C and D are images taken on an epifluorescence microscope (Axioplan) using a Chroma GFP filter set 41017 (Chroma, Bellows Falls, VT). E is a dark-field image of the same ovule in D. These images show expression is present in developing fruit. Scale bar in B represents 20 μm, scale bar in E represents 20 μm in C-E. (TIF 4435 kb

The Yamato-type (CY) carbonaceous chondrite group: Analogues for the surface of asteroid Ryugu?

We report new mineralogical, petrographic and noble gas analyses of the carbonaceous chondrite meteorites Y-82162 (C1/2ung), Y-980115 (CI1), Y-86029 (CI1), Y-86720 (C2ung), Y-86789 (C2ung), and B-7904 (C2ung). Combining our results with literature data we show that these meteorites experienced varying degrees of aqueous alteration followed by short-lived thermal metamorphism at temperatures of >500 °C. These meteorites have similar mineralogy, textures and chemical characteristics suggesting that they are genetically related, and we strongly support the conclusion of Ikeda (1992) that they form a distinct group, the CYs (“Yamato-type”). The CY chondrites have the heaviest oxygen isotopic compositions (δ17O ˜12‰, δ18O ˜22‰) of any meteorite group, high abundances of Fe-sulphides (˜10 ‒ 30 vol%) and phosphates, and contain large grains of periclase and unusual objects of secondary minerals not reported in other carbonaceous chondrites. These features cannot be attributed to parent body processes alone, and indicate that the CYs had a different starting mineralogy and/or alteration history to other chondrite groups, perhaps because they formed in a different region of the protoplanetary disk. The short cosmic-ray exposure ages (≤1.3 Ma) of the CY chondrites suggest that they are derived from a near-Earth source, with recent observations by the Hayabusa2 spacecraft highlighting a possible link to the rubble-pile asteroid Ryugu

Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF

The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described