6,848 research outputs found

    Why Emissions Pricing Can’t Do It Alone

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    This article explores whether emissions pricing is sufficient to achieve the low-emissions transition in Aotearoa New Zealand. It draws on a critical review of the international literature on emissions pricing, policy interactions and political economy to make three broad arguments. First, that emissions pricing alone cannot be expected to induce the necessary levels of behaviour change and technological transition in the urgent time frame required. Second, non-pricing policies can deliver emissions reductions, even within the context of emissions trading under a volume cap. Third, even if emissions pricing could induce sufficient change, there are political economy constraints on reaching the adequate price in a feasible and equitable way. Consequently, we argue that the weight of evidence lies with utilising emissions pricing as part of a policy mix

    Conditional Spectral Analysis of Replicated Multiple Time Series with Application to Nocturnal Physiology

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    This article considers the problem of analyzing associations between power spectra of multiple time series and cross-sectional outcomes when data are observed from multiple subjects. The motivating application comes from sleep medicine, where researchers are able to non-invasively record physiological time series signals during sleep. The frequency patterns of these signals, which can be quantified through the power spectrum, contain interpretable information about biological processes. An important problem in sleep research is drawing connections between power spectra of time series signals and clinical characteristics; these connections are key to understanding biological pathways through which sleep affects, and can be treated to improve, health. Such analyses are challenging as they must overcome the complicated structure of a power spectrum from multiple time series as a complex positive-definite matrix-valued function. This article proposes a new approach to such analyses based on a tensor-product spline model of Cholesky components of outcome-dependent power spectra. The approach flexibly models power spectra as nonparametric functions of frequency and outcome while preserving geometric constraints. Formulated in a fully Bayesian framework, a Whittle likelihood based Markov chain Monte Carlo (MCMC) algorithm is developed for automated model fitting and for conducting inference on associations between outcomes and spectral measures. The method is used to analyze data from a study of sleep in older adults and uncovers new insights into how stress and arousal are connected to the amount of time one spends in bed

    Takeoff/approach noise for a model counterrotation propeller with a forward-swept upstream rotor

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    A scale model of a counterrotating propeller with forward-swept blades in the forward rotor and aft-swept blades in the aft rotor (designated F39/A31) has been tested in the NASA Lewis 9- by 15-Foot Anechoic Wind Tunnel. This paper presents aeroacoustic results at a takeoff/approach condition of Mach 0.20. Laser Doppler velocimeter results taken in a plane between the two rotors are also included to quantify the interaction flow field. The intention of the forward-swept design is to reduce the magnitude of the forward rotor tip vortex and/or wakes which impinge on the aft rotor, thus lowering the interaction tone levels. A reference model propeller (designated F31/A31), having aft-swept blades in both rotors, was also tested. Aeroelastic performance of the F39/A31 propeller was disappointing. The forward rotor tip region tended to untwist toward higher effective blade angles under load. The forward rotor also exhibited steady state blade flutter at speeds and loadings well below the design condition. The noise results, based on sideline acoustic data, show that the interaction tone levels were up to 8 dB higher with the forward-swept design compared to those for the reference propeller at similar operating conditions, with these tone level differences extending down to lower propeller speeds where flutter did not occur. These acoustic results are for a poorly-performing forward-swept propeller. It is quite possible that a properly-designed forward-swept propeller would exhibit substantial interaction tone level reductions

    Consumption inequality and income uncertainty

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    This paper places the debate over using consumption or income in studies of inequality growth in a formal intertemporal setting. It highlights the importance of permanent and transitory income uncertainty in the evaluation of growth in consumption inequality. We derive conditions under which the growth of variances and covariances of income and consumption can be used to separately identify the growth in the variance of permanent and transitory income shocks. Household data from Britain for the period 1968-1992 are used to show a strong growth in transitory inequality toward the end of this period, while younger cohorts are shown to face significantly higher levels of permanent inequality

    Managing identity conflicts in organizations: a case study of one welfare non-profit

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    How nonprofit organizations manage multiple and conflicting identities is not well understood. In a case study of a nonprofit welfare organization, we use Pratt and Foreman’s (2000) framework of identity management responses to illuminate different ways that nonprofit organizations can seek to manage and potentially resolve identity conflicts. We focus on the actual practices nonprofit organizations use to manage multiple identities and, in particular, reveal the important role of organizational routines and artefacts in facilitating or constraining particular identity management responses

    Ultrastructure of the salivary glands, alimentary canal and bacteria-like organisms in the Asian citrus psyllid, vector of citrus huanglongbing disease bacteria

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    AbstractThe Asian citrus psyllid (ACP, Diaphorina citri, Hemiptera: Liviidae) is the principal vector of Candidatus Liberibacter asiaticus (Las), the putative bacterial agent of citrus greening/huanglongbing (HLB); currently the most serious citrus disease worldwide. Las is transmitted in a persistent–propagative manner by ACP, and the salivary glands and midgut have been suggested as transmission barriers that can impede translocation of Las within the vector. However, no detailed ultrastructural studies have been reported on these organs in this or other psyllid species, although some bacterium-like structures have been described in them and assumed to be the causal agents of HLB. In this study, we describe the ultrastructure of the salivary glands, filter chamber, other parts of the alimentary canal, and other organs and tissues of ACP including the compound ganglionic mass (in the thorax) and the bacteriome (in the abdomen). Furthermore, in addition to two ultrastructurally apparently different symbiotic bacteria found in the bacteriome, other morphological types of bacteria were found in the gut epithelial cells and salivary glands of both Las-infected (quantitative polymerase chain reaction positive) and noninfected (quantitative polymerase chain reaction negative) ACP. These results show the importance of immunolabeling, fluorescence in situ hybridization, or other labeling techniques that must be used before identifying any bacterium-like structures in ACP or other vectors as Las or other possible agents of HLB. This ultrastructural investigation should help future work on the cellular and subcellular aspects of pathogen–psyllid relationships, including the study of receptors, binding sites, and transmission barriers of Las and other pathogens within their psyllid vectors

    Best Management Practices for Corn Production in South Dakota: Corn Planting Guide

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    Obtaining maximum profit from a corn crop depends on the timely planting of an appropriate hybrid, at the proper depth, with a planter that evenly spaces the seed. The success of a corn crop is dependent on equipment maintenance, seedbed preparation, the development of a sound fertility and pest management program, and planting the seed. Early planting is best, but temperatures should be warm enough to assure quick germination and emergence, and late enough to avoid hard frosts. Planting-opportunity windows can be narrow due to spring rains or a late warm-up. Time spent in the off-season maintaining equipment and planning tentative season-long schedules can increase planting efficiency. This section discusses planter maintenance, planting date, replanting considerations, seeding rate, and planting depth

    Control of anthocyanin and non-flavonoid compounds by anthocyanin-regulating MYB and bHLH transcription factors in Nicotiana benthamiana leaves

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    Coloration of plant organs such as fruit, leaves and flowers through anthocyanin production is governed by a combination of MYB and bHLH type transcription factors. In this study we introduced Rosea1 (ROS1, a MYB type) and Delila (DEL, a bHLH type), into Nicotiana benthamiana leaves by agroinfiltration. ROS1 and DEL form a pair of well-characterized transcription factors from Snapdragon (Antirrhinum majus), which specifically induce anthocyanin accumulation when expressed in tomato fruit. In N. benthamiana, robust induction of a single anthocyanin, delphinidin-3-rutinoside (D3R) was observed after expression of both ROS1 and DEL. Surprisingly in addition to D3R, a range of additional metabolites were also strongly and specifically up-regulated upon expression of ROS1 and DEL. Except for the D3R, these induced compounds were not derived from the flavonoid pathway. Most notable among these are nornicotine conjugates with butanoyl, hexanoyl and octanoyl hydrophobic moieties, and phenylpropanoid-polyamine conjugates such as caffeoyl-putrescine. The defensive properties of the induced molecules were addressed in bioassays using the tobacco specialist lepidopteran insect Manduca sexta. Our study showed that the effect of ROS1 and DEL expression in N. benthamiana leaves extends beyond the flavonoid pathway. Apparently the same transcription factor may regulate different secondary metabolite pathways in different plant species
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