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Children born very preterm (VP) display altered growth in corticolimbic structures compared with full-term peers. Given the association between the cortiocolimbic system and anxiety, this study aimed to compare developmental trajectories of corticolimbic regions in VP children with and without anxiety diagnosis at 13 years.
MRI data from 124 VP children were used to calculate whole brain and corticolimbic region volumes at term-equivalent age (TEA), 7 and 13 years. The presence of an anxiety disorder was assessed at 13 years using a structured clinical interview.
VP children who met criteria for an anxiety disorder at 13 years (n = 16) displayed altered trajectories for intracranial volume (ICV, p < 0.0001), total brain volume (TBV, p = 0.029), the right amygdala (p = 0.0009) and left hippocampus (p = 0.029) compared with VP children without anxiety (n = 108), with trends in the right hippocampus (p = 0.062) and left medial orbitofrontal cortex (p = 0.079). Altered trajectories predominantly reflected slower growth in early childhood (0–7 years) for ICV (β = −0.461, p = 0.020), TBV (β = −0.503, p = 0.021), left (β = −0.518, p = 0.020) and right hippocampi (β = −0.469, p = 0.020) and left medial orbitofrontal cortex (β = −0.761, p = 0.020) and did not persist after adjusting for TBV and social risk.
Region- and time-specific alterations in the development of the corticolimbic system in children born VP may help to explain an increase in anxiety disorders observed in this population.
To identify attention profiles at 7 and 13 years, and transitions in attention profiles over time in children born very preterm (VP; <30 weeks’ gestation) and full term (FT), and examine predictors of attention profiles and transitions.
Participants were 167 VP and 60 FT children, evaluated on profiles across five attention domains (selective, shifting and divided attention, processing speed, and behavioral attention) at 7 and 13 years using latent profile analyses. Transitions in profiles were assessed with contingency tables. For VP children, biological and social risk factors were tested as predictors with a multinomial logistic regression.
At 7 and 13 years, three distinct profiles of attentional functioning were identified. VP children were 2–3 times more likely to show poorer attention profiles compared with FT children. Transition patterns between 7 and 13 years were stable average, stable low, improving, and declining attention. VP children were two times less likely to have a stable average attention pattern and three times more likely to have stable low or improving attention patterns compared with FT children. Groups did not differ in declining attention patterns. For VP children, brain abnormalities on neonatal MRI and greater social risk at 7 years predicted stable low or changing attention patterns over time.
VP children show greater variability in attention profiles and transition patterns than FT children, with almost half of the VP children showing adverse attention patterns over time. Early brain pathology and social environment are markers for attentional functioning.
A new optimized quasi-helically symmetric configuration is described that has the desirable properties of improved energetic particle confinement, reduced turbulent transport by three-dimensional shaping and non-resonant divertor capabilities. The configuration presented in this paper is explicitly optimized for quasi-helical symmetry, energetic particle confinement, neoclassical confinement and stability near the axis. Post optimization, the configuration was evaluated for its performance with regard to energetic particle transport, ideal magnetohydrodynamic stability at various values of plasma pressure and ion temperature gradient instability induced turbulent transport. The effects of discrete coils on various confinement figures of merit, including energetic particle confinement, are determined by generating single-filament coils for the configuration. Preliminary divertor analysis shows that coils can be created that do not interfere with expansion of the vessel volume near the regions of outgoing heat flux, thus demonstrating the possibility of operating a non-resonant divertor.
The family physician is key to facilitating access to psychiatric treatment for young people with first-episode psychosis, and this involvement can reduce aversive events in pathways to care. Those who seek help from primary care tend to have longer intervals to psychiatric care, and some people receive ongoing psychiatric treatment from the family physician.
Our objective is to understand the role of the family physician in help-seeking, recognition and ongoing management of first-episode psychosis.
We will use a mixed-methods approach, incorporating health administrative data, electronic medical records (EMRs) and qualitative methodologies to study the role of the family physician at three points on the pathway to care. First, help-seeking: we will use health administrative data to examine access to a family physician and patterns of primary care use preceding the first diagnosis of psychosis; second, recognition: we will identify first-onset cases of psychosis in health administrative data, and look back at linked EMRs from primary care to define a risk profile for undetected cases; and third, management: we will examine service provision to identified patients through EMR data, including patterns of contacts, prescriptions and referrals to specialised care. We will then conduct qualitative interviews and focus groups with key stakeholders to better understand the trends observed in the quantitative data.
These findings will provide an in-depth description of first-episode psychosis in primary care, informing strategies to build linkages between family physicians and psychiatric services to improve transitions of care during the crucial early stages of psychosis.
Thin-section petrography is a crucial tool for the study of archaeological ceramics, and in recent years, image analysis has emerged as a powerful quantitative enhancement of that tool. Exploratory applications of image analysis to archaeological ceramic thin sections, and related work by sedimentary geologists, have indicated its usefulness to the field. In this paper, we first present the results of experimental work testing the consistency and reproducibility of image analysis. We identify procedures for fast and reliable analysis of thin sections using laboratory-prepared ceramic specimens of simple clay-sand systems. We then show how those procedures can be slightly modified to accommodate more complex archaeological specimens. We conclude with a discussion of the role of image analysis within the overall context of thin-section petrography of ceramic materials, as one among a repertoire of techniques, adding quantitative data and increasing the usefulness of ceramic thin sections for addressing archaeological research questions.
Pores in archaeological ceramics can form in a number of different ways, and reflect both deliberate choices and uncontrollable factors. Characterizing porosity by digital image analysis of thin sections holds a number of advantages as well as limitations. We present the results of experiments aimed at improving this method, focusing on high-resolution scans of entire thin sections. We examine the reproducibility of pore measurements by petrographic image analysis of ceramic thin sections using laboratory-prepared specimens of clay mixed with sand of known amount and size. We outline protocols for measuring Total Optical Porosity, using the Image-Pro Premier software package. We also briefly discuss use of pore size and pore shape (aspect ratio and roundness) in characterizing archaeological ceramics. While discerning reasons for observed amounts, sizes, and shapes of pores is an extremely complex problem, the quantitative analysis of ceramic porosity is one tool for characterizing a ware and comparing a product to others. The methods outlined here are applied to a case study comparing historic bricks from the Read House in New Castle, Delaware; the porosity studies indicate that different construction campaigns used bricks from different sources.
Whether property rights evolve from the bottom up or are assigned directly by government, they can provide important benefits by supporting environmental markets. Chapters 3 and 4 provided examples of the evolution of informal property rights and their role in providing environmental quality. In this chapter we turn to cases where environmental markets are based on formal property rights codified through a political and legal process. The examples are water rights, conservation credits, emission allowances, and tradable fishery shares. The details illustrate how environmental markets work and the nature of the property rights underwriting them.
In all of the cases, the rights are not based on fee simple titles but instead are use privileges. This distinction is important because privileges are just that, use opportunities that can be modified, reassigned, or revoked more easily by political or judicial action than is the case with formal title. Political action occurs through Congress and regulatory agencies, and judicial review through the courts. Use privileges have no constitutional takings protections, and monetary losses from government interventions are not compensable. Although use privileges give regulatory agencies greater flexibility, they are more uncertain and can have shorter time horizons and weaker incentives for investing in or reallocating the environmental resource than can more secure formal rights. When property rights are vague, environmental markets are weakened, and more environmental benefits must come from command-and-control regulation and tax policies. We examined the problems with those approaches in Chapters 2 and 3. A major lesson of this chapter is that property rights must be protected from regulatory takings if we are to harness markets to improve environmental quality. We provide examples of successful markets, some emerging ones, and some that have been weakened by political and bureaucratic intervention. This range of experiences reveals what is possible, what more remains, and what dangers can arise. We begin with two successful instances regarding water.
Environmental economics often focuses on the failure of markets to allocate and manage natural and environmental resources efficiently. Under the banner of externalities, markets fail either because private costs are less than social costs or because private benefits are less than social benefits. The former results in overuse of the environment such as overfishing, excessive air and water emissions, and overpumping of groundwater basins. The latter results in too little provision of public goods such as preservation of endangered species habitats, maintenance of adequate stream flows for recreation or pollution dilution, or investment in biodiversity.
The policy remedies for market failure include both taxes to raise private costs to social costs and regulation to hold quantities to the optimal amount. There is little discussion in the literature on the process through which taxes or regulations are devised and implemented that lead to socially beneficial improvements. Are the costs of securing tax or regulatory policies less than the benefits, or alternatively is the route one of rent seeking and interest-group politics? What motivates politicians and regulatory agencies to adopt taxes or regulations that lead to effective correction of the externality? Because taxes are rarely implemented, at least in the United States, the obvious question is why, if they are so beneficial? Is their absence an indication that political interests dominate efficiency goals? Similarly, command-and-control regulations are adopted to limit use of air, water, fisheries, forests, and other resources, but they are costly and often do not capture the incentives of resource users to engage in more optimal production. For example, in the case of fisheries, fishing season limits have been a common regulatory response to overharvest, but they generally result in twenty-four-hour fish derbies, excessive investment in capital and labor to win the derby, and a glut of fish during the season. Regulations on the number of vessels lead to larger ones with more sophisticated equipment to find and catch fish.
The objective of this book is to promote greater consideration of property rights and markets in addressing environmental problems. Although there is movement toward increased use of market approaches with the adoption of cap-and-trade in controlling air emissions, fishery harvests, and land use, there have been bumps in the road. Several environmental markets are thin with few trades, in others, prices have trended toward regulatory-set floors, and many have insecure property rights that limit incentives for long-term investment and conservation. We explore why that might be the case and what options exist for, and what benefits may be derived from, expansion. We believe that more can be done to improve the efficient provision of environmental quality through the greater definition of property rights and market exchange.
THE RECIPROCAL NATURE OF THE PROBLEM: NORMATIVE AND POSITIVE ANALYSIS
The manner in which our approach differs from standard presentations is that we recognize environmental problems as ones of reciprocal costs. Natural resource and environmental problems arise when people with diverse demands compete for the use of environmental goods. For example, the policy debate over air pollution levels reveals competition between those who want to use the air for low-cost waste disposal or to facilitate use of certain fossil fuels and those who want to breathe clean air, avoid the health effects of ingesting contaminants, have clear views of the surrounding terrain, or mitigate potential climate change. Debates over clear-cut forests reflect competition between those who demand wood products at low cost and seek maintenance of timber-based industries and communities and those who prefer forests for hiking trails, wildlife habitat, or carbon sequestration and the expansion of ecotourism. Concerns about overfishing indicate competition between those who want fish now, regardless of stock impacts, and those who want a sustainable yield into the future. In a positive sense, these are competing and conflicting demands. The different effects on welfare if one use dominates the other often are not obvious, although advocates on both sides have clear opinions. The ultimate answer depends upon the benefits and costs of each alternative and their distribution across society.
In a nutshell, this book has made the case for environmental markets based on well-defined, enforced, and transferable property rights. If all three exist, owners have an incentive to consider the full effects of their actions as they engage in Coasean bargaining to mitigate the losses of open access. Property rights – informal or formal, individual or group – help reduce the tragedy of the commons by assigning the costs and benefits of decisions, making the opportunity costs clear, limiting the race to capture rents, and allowing owners to reallocate resources across uses and across time. Property rights identify the relevant people who have a stake in the resource and who can engage in negotiation and contracting. Without them, there is little basis for bargaining. Absent exclusivity, any party can enter and compete for resource rents regardless of any agreement made by an initial group of users. Because everyone knows this potential, bargaining for environmental quality cannot gain much traction.
Property rights define expectations regarding entitlements from resource use, investment, coordination, and cooperation, relative to nonowners. They provide incentives for considering long-time horizons and for long-lasting collaboration. This certainly is necessary because most environmental and natural resource challenges involve the long term, require exclusion, and necessitate teamwork for solution. Secure property rights economize on the transaction costs of decision making, allowing market exchange, investment, and experimentation to take place quickly in response to new information regarding the environmental and natural resource asset. Given the limited scientific knowledge that often accompanies many open-access problems, the information generation and flexibility of markets are particularly critical.
In this chapter, we examine broader environmental and natural resource open-access problems that cross political jurisdictions. To get insights into what opportunities and challenges exist for the use of environmental markets, we examine case studies where multi-jurisdictional environmental markets have been implemented and where they have not. The nature of the underlying property rights helps to explain the differences in the potential for markets.
In earlier chapters, the analysis and examples indicated that environmental markets appear to work best when addressing more localized open-access problems that are narrow in scope, where property rights are secure, and where the parties involved share common incentives regarding resource conservation. Because immediate users often are both the source and the solution to the problem, they are more likely to internalize the costs and benefits of resolving it. At the local level, the costs of measuring and bounding environmental assets and demarcating property rights are generally lower. Moreover, confined open-access problems typically fall under a single political authority. In this situation, property rights, markets, and any distributional or administrative conflicts surrounding them are handled by politicians and bureaucratic officials who are at least loosely responsible to local political constituencies. Parties with more actual experience with the resource typically have the best information about it, the losses due to open access, the effects of human actions relative to more system-wide factors, and potential remedies.