Orbital Observations of Dust Lofted by Daytime Convective Turbulence

Over the past several decades, orbital observations of lofted dust have revealed the importance of mineral aerosols as a climate forcing mechanism on both Earth and Mars. Increasingly detailed and diverse data sets have provided an ever-improving understanding of dust sources, transport pathways, and sinks on both planets, but the role of dust in modulating atmospheric processes is complex and not always well understood. We present a review of orbital observations of entrained dust on Earth and Mars, particularly that produced by the dust-laden structures produced by daytime convective turbulence called “dust devils”. On Earth, dust devils are thought to contribute only a small fraction of the atmospheric dust budget; accordingly, there are not yet any published accounts of their occurrence from orbit. In contrast, dust devils on Mars are thought to account for several tens of percent of the planet’s atmospheric dust budget; the literature regarding martian dust devils is quite rich. Because terrestrial dust devils may temporarily contribute significantly to local dust loading and lowered air quality, we suggest that martian dust devil studies may inform future studies of convectively-lofted dust on Earth

Dust Devil Sediment Transport: From Lab to Field to Global Impact

The impact of dust aerosols on the climate and environment of Earth and Mars is complex and forms a major area of research. A difficulty arises in estimating the contribution of small-scale dust devils to the total dust aerosol. This difficulty is due to uncertainties in the amount of dust lifted by individual dust devils, the frequency of dust devil occurrence, and the lack of statistical generality of individual experiments and observations. In this paper, we review results of observational, laboratory, and modeling studies and provide an overview of dust devil dust transport on various spatio-temporal scales as obtained with the different research approaches. Methods used for the investigation of dust devils on Earth and Mars vary. For example, while the use of imagery for the investigation of dust devil occurrence frequency is common practice for Mars, this is less so the case for Earth. Modeling approaches for Earth and Mars are similar in that they are based on the same underlying theory, but they are applied in different ways. Insights into the benefits and limitations of each approach suggest potential future research focuses, which can further reduce the uncertainty associated with dust devil dust entrainment. The potential impacts of dust devils on the climates of Earth and Mars are discussed on the basis of the presented research results

Delineating the molecular and phenotypic spectrum of the SETD1B-related syndrome

Purpose: Pathogenic variants in SETD1B have been associated with a syndromic neurodevelopmental disorder including intellectual disability, language delay, and seizures. To date, clinical features have been described for 11 patients with (likely) pathogenic SETD1B sequence variants. This study aims to further delineate the spectrum of the SETD1B-related syndrome based on characterizing an expanded patient cohort. Methods: We perform an in-depth clinical characterization of a cohort of 36 unpublished individuals with SETD1B sequence variants, describing their molecular and phenotypic spectrum. Selected variants were functionally tested using in vitro and genome-wide methylation assays. Results: Our data present evidence for a loss-of-function mechanism of SETD1B variants, resulting in a core clinical phenotype of global developmental delay, language delay including regression, intellectual disability, autism and other behavioral issues, and variable epilepsy phenotypes. Developmental delay appeared to precede seizure onset, suggesting SETD1B dysfunction impacts physiological neurodevelopment even in the absence of epileptic activity. Males are significantly overrepresented and more severely affected, and we speculate that sex-linked traits could affect susceptibility to penetrance and the clinical spectrum of SETD1B variants. Conclusion: Insights from this extensive cohort will facilitate the counseling regarding the molecular and phenotypic landscape of newly diagnosed patients with the SETD1B-related syndrome

TRADE OPENNESS: AN AUSTRALIAN PERSPECTIVE

Australia's external trade is relatively low compared with the size of its economy. Indeed, Australia's openness ratio (exports plus imports as a proportion of GDP) in 2002 was the third-lowest among the 30�OECD countries. This paper seeks to understand Australia's low openness by analysing the empirical determinants of aggregate country trade. We present an equation for country openness which explains a substantial amount of the cross-country variation. The most important explanators of openness are population and a measure of distance to potential trade partners. Countries with larger populations trade less, as do countries that are relatively more remote. Furthermore, after controlling for trade policy there is little evidence of a positive correlation between openness and economic development. The openness equation suggests that Australia's level of trade is relatively close to what would be expected. The most important factors in explaining Australia's low openness ratio are its large geographic size and distance to the rest of the world. Copyright 2006 The Authors Journal compilation 2006 Blackwell Publishing Ltd/University of Adelaide and Flinders University.

The Institutional Determinants of Bilateral Trade Patterns

This paper studies the effect of institutions on trade flows, using a gravity model approach. Standard gravity equations incorporate factors such as geographical proximity, language, trade policy and common history as explanatory factors for variation in bilateral trade that reflect the costs of trade across geographical and cultural distance. We extend this type of analysis by focusing on the relevance of the quality of governance and the extent of familiarity with the resulting framework of rules and norms in explaining variation in bilateral trade patterns. More specifically, we test whether institutional homogeneity and institutional quality have an independent impact on the trade volume between pairs of countries. We find that having a similar institutional framework promotes bilateral trade by 13%, on average. Furthermore, a better quality of formal institutions tends to coincide with more trade. Depending on being either importer or exporter, an increase in overall institutional quality of one standard deviation from the mean leads to an estimated increase of 30-44% in bilateral trade. Copyright WWZ and Helbing & Lichtenhahn Verlag AG 2004.

Exchange Rate Uncertainty and Agricultural Trade

Using a sample of bilateral trade flows across ten developed countries between 1974 and 1995, this article explores the effect of exchange rate uncertainty on the growth of agricultural trade as compared to other sectors. Based on a gravity model that controls for other factors likely to determine bilateral trade, the results show that real exchange rate uncertainty has had a significant negative effect on agricultural trade over this period. Moreover, the negative impact of uncertainty on agricultural trade has been more significant compared to other sectors. Copyright 2002, Oxford University Press.