502 research outputs found
Old Tools, New Ways of Using Them: Harnessing Expert Opinions to Plan for Surprise in Marine Socio-Ecological Systems
Copyright © 2019 Gladstone-Gallagher, Hope, Bulmer, Clark, Stephenson, Mangan, Rullens, Siwicka, Thomas, Pilditch, Savage and Thrush. With globally accelerating rates of environmental disturbance, coastal marine ecosystems are increasingly prone to non-linear regime shifts that result in a loss of ecosystem function and services. A lack of early-detection methods, and an over reliance on limits-based approaches means that these tipping points manifest as surprises. Consequently, marine ecosystems are notoriously difficult to manage, and scientists, managers, and policy makers are paralyzed in a spiral of ecosystem degradation. This paralysis is caused by the inherent need to quantify the risk and uncertainty that surrounds every decision. While progress toward forecasting tipping points is ongoing and important, an interim approach is desperately needed to enable scientists to make recommendations that are credible and defensible in the face of deep uncertainty. We discuss how current tools for developing risk assessments and scenario planning, coupled with expert opinions, can be adapted to bridge gaps in quantitative data, enabling scientists and managers to prepare for many plausible futures. We argue that these tools are currently underutilized in a marine cumulative effects context but offer a way to inform decisions in the interim while predictive models and early warning signals remain imperfect. This approach will require redefining the way we think about managing for ecological surprise to include actions that not only limit drivers of tipping points but increase socio-ecological resilience to yield satisfactory outcomes under multiple possible futures that are inherently uncertain
Structural Change and the Fall of Income Inequality in Latin America : Agricultural Development, Inter-sectoral Duality, and the Kuznets Curve
In this study we approach the recent decline in income inequality in Latin America from the perspective of structural change with a focus on the relative performance of the agricultural sector. Our focus is on the underlying forces implied by Kuznets (1965). We zoom in on the relative performance of agriculture in the development process and the rural-urban duality and pay particular attention to the last couple of decades in relation to the entire post-1950 period. We attempt to estimate empirically possible theoretical relations with regard to these patterns by posing the following basic questions: how does the resurgence of agriculture relate to the reduction of income inequality and to what extent is this an expression of Latin America moving downward on the Kuznets curve? The literature on agriculture’s relation to the recent changes of income distribution in Latin America is quite limited. For instance, in a recent ECLAC report titled “Structural change for equality” (2012), the role of agriculture is not even mentioned. By agriculture we mean both farming and agro-business that processes and transports that output. To our knowledge, this paper is the first attempt to investigate this relationship for the recent decades in the perspective of structural change in Latin America. There are strong theoretical reasons to connect agricultural development to income distribution. The closing of the rural-urban income gap reflects what Reynolds (1975) called a “dynamic” transformation of agriculture and relates to the contribution agriculture provides for overall growth of the economy. In addition, the elasticity of poverty reduction with respect to growth is estimated to be stronger when growth emanates in the agricultural sector (Ravallion and Chen 2007, de Janvry and Sadoulet 2009). Productivity growth in the lagging sector should also contribute to sectoral labor productivity to convergence and thus helps to reduce inequality (Timmer 1988). For these reasons, the resurgence of agriculture driven partly by improving commodity prices should be given due attention when assessing the decline in income inequality in Latin America. According to the logic of the Kuznets curve, the hypothesized “turning point” of the inverted U-curve is generated by a reduction of income inequality in one or both of the sectors and/or a reduction of the rural-urban income gap as the weight of the agricultural sector diminishes, and the income per capita gap between them declines. We find that the recent decline in income inequality is related to the recent resurgence of Latin American agriculture, and, by inference, its lack of decline across most of the 20th century must be related to a lack of productivity change in agriculture. We provide estimates showing that during the recent decades inter-sectoral duality has been reduced by agricultural productivity growth. The duality expressed as an inter-sectoral Gini shows the shape of an inverted U-curve and as such the closing of the rural-urban income gap corroborates with the theoretical expectations postulated by Kuznets. The wider implication of the study is, however, that with slower growth in agricultural labor productivity, continuing improvement in the income distribution becomes more difficult. In the absence of strong manufacturing growth, agriculture might be able to reduce income inequality further if agro-industries remain unskilled labor intensive, thus raising the opportunity cost of unskilled workers. On the other hand, the traditional service sector has perhaps become the “new agricultural sector” in terms of productivity and labor surplus. In other words, the source of the remaining dualism does not come only from rural areas, but also from urban areas
Production, characterization, and antigen specificity of recombinant 62-71-3, a candidate monoclonal antibody for rabies prophylaxis in humans
Rabies kills many people throughout the developing world every year. The murine monoclonal antibody (mAb) 62-71-3 was recently identified for its potential application in rabies postexposure prophylaxis (PEP). The purpose here was to establish a plant-based production system for a chimeric mouse-human version of mAb 62-71-3, to characterize the recombinant antibody and investigate at a molecular level its interaction with rabies virus glycoprotein. Chimeric 62-71-3 was successfully expressed in Nicotiana benthamiana. Glycosylation was analyzed by mass spectroscopy; functionality was confirmed by antigen ELISA, as well as rabies and pseudotype virus neutralization. Epitope characterization was performed using pseudotype virus expressing mutagenized rabies glycoproteins. Purified mAb demonstrated potent viral neutralization at 500 IU/mg. A critical role for antigenic site I of the glycoprotein, as well as for two specific amino acid residues (K226 and G229) within site I, was identified with regard to mAb 62-71-3 neutralization. Pseudotype viruses expressing glycoprotein from lyssaviruses known not to be neutralized by this antibody were the controls. The results provide the molecular rationale for developing 62-71-3 mAb for rabies PEP; they also establish the basis for developing an inexpensive plant-based antibody product to benefit low-income families in developing countries.—Both, L., van Dolleweerd, C., Wright, E., Banyard, A. C., Bulmer-Thomas, B., Selden, D., Altmann, F., Fooks, A. R., Ma, J. K.-C. Production, characterization, and antigen specificity of recombinant 62-71-3, a candidate monoclonal antibody for rabies prophylaxis in humans
Functional Inequality in Latin America: News from the Twentieth Century
We report on a novel approach for the measurement of gas adsorption in microporous solids using X-ray computed tomography (CT) that we refer to as digital adsorption. Similar to conventional macroscopic methods, the proposed protocol combines observations with an inert and an adsorbing gas to produce equilibrium isotherms in terms of the truly measurable quantity in an adsorption experiment, namely the surface excess. Most significantly, X-ray CT allows probing the adsorption process in three dimensions, so as to build spatially-resolved adsorption isotherms with a resolution of approximately 10 mm3 within a fixed-bed column. Experiments have been carried out at 25 C and in the pressure range 1-30bar using CO2 on activated carbon, zeolite 13X and glass beads (as control material), and results are validated against literature data. A scaling approach was applied to analyze the whole population of measured adsorption isotherms (~7600), leading to single universal adsorption isotherm curves that are descriptive of all voxels for a given adsorbate-adsorbent system. By analyzing the adsorption heterogeneity at multiple length scales (1 mm3 to 1 cm3), packing heterogeneity was identified as the main contributor for the larger spatial variability in the adsorbed amount observed for the activated carbon rods as compared to zeolite pellets. We also show that this technique is readily applicable to a large spectrum of commercial porous solids, and that it can be further extended to weakly adsorbing materials with appropriate protocols that reduce measurement uncertainties. As such, the obtained results prove the feasibility of digital adsorption and highlight substantial opportunities for its wider use in the field of adsorptive characterization of porous solids
The Emergence of Shell Valuable Exchange in the New Guinea Highlands
Shell valuable exchange in the New Guinea Highlands has been a key
interest in anthropology, providing insight into economics, aesthetics, and social
stratification amongst banded communities. This paper describes how shell exchange
at ethnographic present reflects deeper historical processes. We trace the origins and
subsequent changes in shell use from the terminal Pleistocene to the Late Holocene at
the site of Kiowa in Chimbu Province, Papua New Guinea. Zooarchaeological and
technological analyses of Kiowa’s shell artifacts indicates riverine mussel was
procured locally from the terminal Pleistocene (9,500–10,000 years ago) and featured
as a minor component in the diet into the recent precolonial period. In contrast,
evidence for marine shell valuables only appears in the Late Holocene in the form of
Trochus armbands and Tegillarca granosa and Polymesoda cf. erosa multifunctional
tools. This challenges ideas that associate the gradual dispersal of marine shell into
the highlands with the spread of agriculture around the Wahgi Valley at the start of
the Holocene, and supports punctuated pulses of coastal contact. In doing so, we
formulate a testable model for the development of shell exchange into the highlands,
with implications for the emergence of stratification and the conduits between the
interior and coast
Social Transfer of Pathogenic Fungus Promotes Active Immunisation in Ant Colonies
Social contact with fungus-exposed ants leads to pathogen transfer to healthy nest-mates, causing low-level infections. These micro-infections promote pathogen-specific immune gene expression and protective immunization of nest-mates
On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection
A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)
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