Heart and Soul in Aristotle

When Aristotle speaks of the soul \u27in the heart\u27 he has in mind the heart as primary and proximate material organ of the soul, the controlling organ originally informed and activated by the soul, upon which all the other organs depend for their formation and activation by the soul. They too live, are informed and activated by the soul, but in a way that is secondary and more remote. To speak of the soul as existing \u27in the heart\u27 is not to deny its presence in the other organs, but to indicate the primary and proximate subject it informs and activates

Three dimensional quantification of soil hydraulic properties using X-ray Computed Tomography and image based modelling

We demonstrate the application of a high-resolution X-ray Computed Tomography (CT) method to quantify water distribution in soil pores under successive reductive drying. We focus on the wet end of the water release characteristic (WRC) (0 to -75 kPa) to investigate changes in soil water distribution in contrasting soil textures (sand and clay) and structures (sieved and field structured), to determine the impact of soil structure on hydraulic behaviour. The 3D structure of each soil was obtained from the CT images (at a 10 µm resolution). Stokes equations for flow were solved computationally for each measured structure to estimate hydraulic conductivity. The simulated values obtained compared extremely well with the measured saturated hydraulic conductivity values. By considering different sample sizes we were able to identify that the smallest possible representative sample size which is required to determine a globally valid hydraulic conductivity

Resonant Absorption as Mode Conversion?

Resonant absorption and mode conversion are both extensively studied mechanisms for wave "absorption" in solar magnetohydrodynamics (MHD). But are they really distinct? We re-examine a well-known simple resonant absorption model in a cold MHD plasma that places the resonance inside an evanescent region. The normal mode solutions display the standard singular resonant features. However, these same normal modes may be used to construct a ray bundle which very clearly undergoes mode conversion to an Alfv\'en wave with no singularities. We therefore conclude that resonant absorption and mode conversion are in fact the same thing, at least for this model problem. The prime distinguishing characteristic that determines which of the two descriptions is most natural in a given circumstance is whether the converted wave can provide a net escape of energy from the conversion/absorption region of physical space. If it cannot, it is forced to run away in wavenumber space instead, thereby generating the arbitrarily small scales in situ that we recognize as fundamental to resonant absorption and phase mixing. On the other hand, if the converted wave takes net energy way, singularities do not develop, though phase mixing may still develop with distance as the wave recedes.Comment: 23 pages, 8 figures, 2 tables; accepted by Solar Phys (July 9 2010

Three Dimensional MHD Wave Propagation and Conversion to Alfven Waves near the Solar Surface. I. Direct Numerical Solution

The efficacy of fast/slow MHD mode conversion in the surface layers of sunspots has been demonstrated over recent years using a number of modelling techniques, including ray theory, perturbation theory, differential eigensystem analysis, and direct numerical simulation. These show that significant energy may be transferred between the fast and slow modes in the neighbourhood of the equipartition layer where the Alfven and sound speeds coincide. However, most of the models so far have been two dimensional. In three dimensions the Alfven wave may couple to the magneto-acoustic waves with important implications for energy loss from helioseismic modes and for oscillations in the atmosphere above the spot. In this paper, we carry out a numerical ``scattering experiment'', placing an acoustic driver 4 Mm below the solar surface and monitoring the acoustic and Alfvenic wave energy flux high in an isothermal atmosphere placed above it. These calculations indeed show that energy conversion to upward travelling Alfven waves can be substantial, in many cases exceeding loss to slow (acoustic) waves. Typically, at penumbral magnetic field strengths, the strongest Alfven fluxes are produced when the field is inclined 30-40 degrees from the vertical, with the vertical plane of wave propagation offset from the vertical plane containing field lines by some 60-80 degrees.Comment: Accepted for the HELAS II/ SOHO 19/ GONG 2007 Topical Issue of Solar Physic

Working Memory, but Not IQ, Predicts Subsequent Learning in Children with Learning Difficulties

The purpose of the present study was to compare the predictive power of working memory and IQ in children identified as having learning difficulties. The term ‘working memory’ refers to the capacity to store and manipulate information in mind for brief periods of time. Working memory capacity is strongly related to learning abilities and academic progress, predicting current and subsequent scholastic attainments of children across the school years in both literacy and numeracy. Children aged between 7 and 11 years were tested at Time 1 on measures of working memory, IQ, and learning. They were then retested two years later on the learning measures. The findings indicated that working memory capacity and domain-specific knowledge at Time 1, but not IQ, were significant predictors of learning at Time 2. The implications for screening and intervention are discussed

POTENTIAL EFFECTS OF CLIMATE CHANGE ON ELEVATIONAL DISTRIBUTIONS OF TROPICAL BIRDS IN SOUTHEAST ASIA

Environmental conditions during the neonatal period can affect the growth, physiology, behavior, and immune function of birds. In many avian studies the nestling environment includes investigator handling of young, which may be stressful. While neonatal handling is known to affect the adult phenotype in rats, the effects of handling on development have rarely been examined in wild birds. We examined the effect of short, repeated periods of neonatal handling on avian growth and immune system development. We subjected American Kestrels (Falco sparverius) and European Starlings (Sturnus vulgaris) to 15 min of daily investigator handling throughout the nestling period, while controls remained undisturbed. Immediately prior to fledging we assessed cutaneous immunity, humoral immunity, mass, and degree of fluctuating asymmetry. Daily handling did not significantly affect any of these measurements. We also addressed the possibility that treatment differences would appear only when birds were challenged with a more substantial stressor by bringing birds into captivity for 24 hr. Captivity did not affect mass, but significantly lowered the cutaneous immune response, although this was independent of treatment. Therefore, brief periods of investigator handling did not appear to affect immune or morphological development in these species, whereas 24 hr of captivity resulted in suppressed cutaneous immune responses

Origins of the Ambient Solar Wind: Implications for Space Weather

The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal heating and the acceleration of the ambient solar wind. We also discuss where the community stands in its ability to forecast how variations in the solar wind (i.e., fast and slow wind streams) impact the Earth. Although the last few decades have seen significant progress in observations and modeling, we still do not have a complete understanding of the relevant physical processes, nor do we have a quantitatively precise census of which coronal structures contribute to specific types of solar wind. Fast streams are known to be connected to the central regions of large coronal holes. Slow streams, however, appear to come from a wide range of sources, including streamers, pseudostreamers, coronal loops, active regions, and coronal hole boundaries. Complicating our understanding even more is the fact that processes such as turbulence, stream-stream interactions, and Coulomb collisions can make it difficult to unambiguously map a parcel measured at 1 AU back down to its coronal source. We also review recent progress -- in theoretical modeling, observational data analysis, and forecasting techniques that sit at the interface between data and theory -- that gives us hope that the above problems are indeed solvable.Comment: Accepted for publication in Space Science Reviews. Special issue connected with a 2016 ISSI workshop on "The Scientific Foundations of Space Weather." 44 pages, 9 figure

Epigenome-wide association study of kidney function identifies trans-ethnic and ethnic-specific loci

BACKGROUND: DNA methylation (DNAm) is associated with gene regulation and estimated glomerular filtration rate (eGFR), a measure of kidney function. Decreased eGFR is more common among US Hispanics and African Americans. The causes for this are poorly understood. We aimed to identify trans-ethnic and ethnic-specific differentially methylated positions (DMPs) associated with eGFR using an agnostic, genome-wide approach. METHODS: The study included up to 5428 participants from multi-ethnic studies for discovery and 8109 participants for replication. We tested the associations between whole blood DNAm and eGFR using beta values from Illumina 450K or EPIC arrays. Ethnicity-stratified analyses were performed using linear mixed models adjusting for age, sex, smoking, and study-specific and technical variables. Summary results were meta-analyzed within and across ethnicities. Findings were assessed using integrative epigenomics methods and pathway analyses. RESULTS: We identified 93 DMPs associated with eGFR at an FDR of 0.05 and replicated 13 and 1 DMPs across independent samples in trans-ethnic and African American meta-analyses, respectively. The study also validated 6 previously published DMPs. Identified DMPs showed significant overlap enrichment with DNase I hypersensitive sites in kidney tissue, sites associated with the expression of proximal genes, and transcription factor motifs and pathways associated with kidney tissue and kidney development. CONCLUSIONS: We uncovered trans-ethnic and ethnic-specific DMPs associated with eGFR, including DMPs enriched in regulatory elements in kidney tissue and pathways related to kidney development. These findings shed light on epigenetic mechanisms associated with kidney function, bridging the gap between population-specific eGFR-associated DNAm and tissue-specific regulatory context

The application of X-ray micro Computed Tomography imaging for tracing particle movement in soil

Despite significant advances in recent years in the application of sensing and imaging technologies to the study of the hydraulic behaviour of soils, our understanding of how solutes and particulate matter move through soil is still limited and often based on idealised soil structures. The aim of this work was to use an appropriate proxy material, in this case (Decabromodiphenyl ether (DBDE)), to represent 1–2 μm sized chemical particles, frequently used in agricultural practices, in order to trace their spatial and temporal movement through a soil column. X-ray Computed Tomography (CT) was employed to map the 3D pore geometry and facilitate visualization of the concentration distribution of the highly X-ray attenuating proxy material as it was applied and subsequently leached through the soil over a 5 hour period. Simultaneously the soil eluate was collected from the bottom of each column and the concentration of proxy material measured using gas chromatography to compare with the imaged data. The method developed for visualizing the tracer material in 3D at the pore-scale was successful. The results demonstrated that the tracer material initially moved rapidly through the upper portion of the soil but subsequently became immobile, despite repeated elution with water as confirmed by imagery. Similar concentrations to those applied to the soil surface were not recorded at any point in time towards the bottom of the soil column. By visualizing the DBDE distribution in 3D it was possible to correlate the highest concentrations of the tracer material with the location of the smaller size pores (i.e. mesopores). Dynamic X-ray CT imaging of tracer materials has considerable potential as a proxy for the visualization of particulate agricultural chemicals that will assist with understanding how their transport behaviour varies both spatially and temporally

Whole genome sequence analysis of pulmonary function and COPD in 19,996 multi-ethnic participants

Chronic obstructive pulmonary disease (COPD), diagnosed by reduced lung function, is a leading cause of morbidity and mortality. We performed whole genome sequence (WGS) analysis of lung function and COPD in a multi-ethnic sample of 11,497 participants from population- and family-based studies, and 8499 individuals from COPD-enriched studies in the NHLBI Trans-Omics for Precision Medicine (TOPMed) Program. We identify at genome-wide significance 10 known GWAS loci and 22 distinct, previously unreported loci, including two common variant signals from stratified analysis of African Americans. Four novel common variants within the regions of PIAS1, RGN (two variants) and FTO show evidence of replication in the UK Biobank (European ancestry n ~ 320,000), while colocalization analyses leveraging multi-omic data from GTEx and TOPMed identify potential molecular mechanisms underlying four of the 22 novel loci. Our study demonstrates the value of performing WGS analyses and multi-omic follow-up in cohorts of diverse ancestry