The Urban Archaeological Supersite Paradigm: Integrating Archaeology and HGIS into Heritage Management

The archaeological heritages of many of the world’s historic cities are at risk. If these urban archaeological resources are destroyed before excavation and documentation using sound archaeological techniques, the material histories of these cities are erased. The Urban Archaeological Supersite Paradigm is presented as means to address some of the threats facing urban archaeological sites. The urban archaeological supersite paradigm is both an applied and a scholarly research framework useful for examining and interpreting the urban past and for helping to address urban archaeological heritage at risk. It conceptualizes the historic city as a supersite made up of numerous archaeological deposits and past activity areas that can reveal the palimpsest of the city. The supersite paradigm is also a mechanism to identify, analyze, and interpret the archaeological heritage of the city via historical GIS (HGIS). Using New Orleans as an example, the research presented involved collecting, creating, and analyzing geospatial data and combining this data in new, meaningful ways within a GIS platform. To showcase the usefulness of implementing the supersite paradigm using HGIS research, three different research questions, at three different scales, are addressed to investigate past histories of New Orleans. The goal is to improve the likelihood that archaeology is incorporated into larger urban planning, management, and implementation processes thereby reducing the threats to the historic urban landscape. Moreover, creating a research paradigm in combination with HGIS creates opportunities for scholars to examine the historic city from a variety of perspectives and helps to link research themes spatially by adding a geographical component

Predicting the cosmological constant with the scale-factor cutoff measure

It is well known that anthropic selection from a landscape with a flat prior distribution of cosmological constant Lambda gives a reasonable fit to observation. However, a realistic model of the multiverse has a physical volume that diverges with time, and the predicted distribution of Lambda depends on how the spacetime volume is regulated. We study a simple model of the multiverse with probabilities regulated by a scale-factor cutoff, and calculate the resulting distribution, considering both positive and negative values of Lambda. The results are in good agreement with observation. In particular, the scale-factor cutoff strongly suppresses the probability for values of Lambda that are more than about ten times the observed value. We also discuss several qualitative features of the scale-factor cutoff, including aspects of the distributions of the curvature parameter Omega and the primordial density contrast Q.Comment: 16 pages, 6 figures, 2 appendice

Constraints on the relationship between stellar mass and halo mass at low and high redshift

We use a statistical approach to determine the relationship between the stellar masses of galaxies and the masses of the dark matter halos in which they reside. We obtain a parameterized stellar-to-halo mass (SHM) relation by populating halos and subhalos in an N-body simulation with galaxies and requiring that the observed stellar mass function be reproduced. We find good agreement with constraints from galaxy-galaxy lensing and predictions of semi-analytic models. Using this mapping, and the positions of the halos and subhalos obtained from the simulation, we find that our model predictions for the galaxy two-point correlation function (CF) as a function of stellar mass are in excellent agreement with the observed clustering properties in the SDSS at z=0. We show that the clustering data do not provide additional strong constraints on the SHM function and conclude that our model can therefore predict clustering as a function of stellar mass. We compute the conditional mass function, which yields the average number of galaxies with stellar masses in the range [m, m+dm] that reside in a halo of mass M. We study the redshift dependence of the SHM relation and show that, for low mass halos, the SHM ratio is lower at higher redshift. The derived SHM relation is used to predict the stellar mass dependent galaxy CF and bias at high redshift. Our model predicts that not only are massive galaxies more biased than low mass ones at all redshifts, but the bias increases more rapidly with increasing redshift for massive galaxies than for low mass ones. We present convenient fitting functions for the SHM relation as a function of redshift, the conditional mass function, and the bias as a function of stellar mass and redshift.Comment: 21 pages, 17 figures, discussion enlarged, one more figure, updated references, accepted for publication in Ap

Are all threats equal? Associations of childhood exposure to physical attack versus threatened violence with preadolescent brain structure

Background: Neurodevelopmental studies of childhood adversity often define threatening experiences as those involving harm or the threat of harm. Whether effects differ between experiences involving harm (“physical attack”) versus the threat of harm alone (“threatened violence”) remains underexplored. We hypothesized that while both types of experiences would be associated with smaller preadolescent global and corticolimbic brain volumes, associations with physical attack would be greater. Methods: Generation R Study researchers (the Netherlands) acquired T1-weighted scans from 2905 preadolescent children, computed brain volumes using FreeSurfer, and asked mothers whether their children ever experienced physical attack (n = 202) or threatened violence (n = 335). Using standardized global (cortical, subcortical, white matter) and corticolimbic (amygdala, hippocampus, anterior cingulate cortex, orbitofrontal cortex) volumes, we fit confounder-adjusted models. Results: Physical attack was associated with smaller global volumes (βcortical=−0.14; 95% CI: −0.26, −0.02); βwhite matter= −0.16; 95% CI: − 0.28, − 0.03) and possibly some corticolimbic volumes, e.g., βamygdala/ICV-adjusted= −0.10 (95% CI: −0.21, 0.01). We found no evidence of associations between threatened violence and smaller volumes in any outcome; instead, such estimates were small, highly uncertain, and positive in direction. Conclusions: Experiences of physical attack and threatened violence may have quantitively different neurodevelopmental effects. Thus, differences between types of threatening experiences may be neurodevelopmentally salient.</p

Behavioral and neurostructural correlates of childhood physical violence victimization:Interaction with family functioning

Violence victimization may cause child behavior problems and neurostructural differences associated with them. Healthy family environments may buffer these effects, but neural pathways explaining these associations remain inadequately understood. We used data from 3154 children (x̅age  = 10.1) to test whether healthy family functioning moderated possible associations between violence victimization, behavior problems, and amygdala volume (a threat-responsive brain region). Researchers collected data on childhood violence victimization, family functioning (McMaster Family Assessment Device, range 0-3, higher scores indicate healthier functioning), and behavior problems (Achenbach Child Behavior Checklist [CBCL] total problem score, range 0-117), and they scanned children with magnetic resonance imaging. We standardized amygdala volumes and fit confounder-adjusted models with "victimization × family functioning" interaction terms. Family functioning moderated associations between victimization, behavior problems, and amygdala volume. Among lower functioning families (functioning score = 1.0), victimization was associated with a 26.1 (95% confidence interval [CI]: 9.9, 42.4) unit higher CBCL behavior problem score, yet victimized children from higher functioning families (score = 3.0) exhibited no such association. Unexpectedly, victimization was associated with higher standardized amygdala volume among lower functioning families (ŷ = 0.5; 95% CI: 0.1, 1.0) but lower volume among higher functioning families (ŷ = -0.4; 95% CI: -0.7, -0.2). Thus, healthy family environments may mitigate some neurobehavioral effects of childhood victimization.</p

Obligate Heterodimerization of the Archaeal Alba2 Protein with Alba1 Provides a Mechanism for Control of DNA Packaging

SummaryOrganisms growing at elevated temperatures face a particular challenge to maintain the integrity of their genetic material. All thermophilic and hyperthermophilic archaea encode one or more copies of the Alba (Sac10b) gene. Alba is an abundant, dimeric, highly basic protein that binds cooperatively and at high density to DNA. Sulfolobus solfataricus encodes a second copy of the Alba gene, and the Alba2 protein is expressed at ∼5% of the level of Alba1. We demonstrate by NMR, ITC, and crystallography that Alba2 exists exclusively as a heterodimer with Alba1 at physiological concentrations and that heterodimerization exerts a clear effect upon the DNA packaging, as observed by EM, potentially by changing the interface between adjacent Alba dimers in DNA complexes. A functional role for Alba2 in modulation of higher order chromatin structure and DNA condensation is suggested

Cosmological Feedback from High-Redshift Dwarf Galaxies

We model how repeated supernova explosions in high-redshift dwarf starburst galaxies drive superbubbles and winds out of the galaxies. We compute the efficiencies of metal and mass ejection and energy transport from the galactic potentials, including the effect of cosmological infall of external gas. The starburst bubbles quickly blow out of small, high-redshift, galactic disks, but must compete with the ram pressure of the infalling gas to escape into intergalactic space. We show that the assumed efficiency of the star formation rate dominates the bubble evolution and the metal, mass, and energy feedback efficiencies. With star formation efficiency f*=0.01, the ram pressure of infall can confine the bubbles around high-redshift dwarf galaxies with circular velocities v_c>52 km/s. We can expect high metal and mass ejection efficiencies, and moderate energy transport efficiencies in halos with v_c~30-50 km/s and f*~0.01 as well as in halos with v_c~100 km/s and f*>>0.01. Such haloes collapse successively from 1-2 sigma peaks in LambdaCDM Gaussian density perturbations as time progresses. These dwarf galaxies can probably enrich low and high-density regions of intergalactic space with metals to 10^-3-10^-2 Zsun as they collapse at z~8 and z<5 respectively. They also may be able to provide adequate turbulent energy to prevent the collapse of other nearby halos, as well as to significantly broaden Lyman-alpha absorption lines to v_rms~20-40 km/s. We compute the timescales for the next starbursts if gas freely falls back after a starburst, and find that, for star formation efficiencies as low as f*<0.01, the next starburst should occur in less than half the Hubble time at the collapse redshift. This suggests that episodic star formation may be ubiquitous in dwarf galaxies.Comment: Accepted for ApJ v613, 60 pages, 15 figure

Prenatal Maternal Stress and Child IQ

The evidence for negative influences of maternal stress during pregnancy on child cognition remains inconclusive. This study tested the association between maternal prenatal stress and child intelligence in 4,251 mother–child dyads from a multiethnic population-based cohort in the Netherlands. A latent factor of prenatal stress was constructed, and child IQ was tested at age 6 years. In Dutch and Caribbean participants, prenatal stress was not associated with child IQ after adjustment for maternal IQ and socioeconomic status. In other ethnicities no association was found; only in the Moroccan/Turkish group a small negative association between prenatal stress and child IQ was observed. These results suggest that prenatal stress does not predict child IQ, except in children from less acculturated minority groups

Glutathione Peroxidase 4 is associated with Neuromelanin in Substantia Nigra and Dystrophic Axons in Putamen of Parkinson's brain

<p>Abstract</p> <p>Background</p> <p>Parkinson's disease is a neurodegenerative disorder characterized pathologically by the loss of nigrostriatal dopamine neurons that project from the substantia nigra in the midbrain to the putamen and caudate nuclei, leading to the clinical features of bradykinesia, rigidity, and rest tremor. Oxidative stress from oxidized dopamine and related compounds may contribute to the degeneration characteristic of this disease.</p> <p>Results</p> <p>To investigate a possible role of the phospholipid hydroperoxidase glutathione peroxidase 4 (GPX4) in protection from oxidative stress, we investigated GPX4 expression in postmortem human brain tissue from individuals with and without Parkinson's disease. In both control and Parkinson's samples, GPX4 was found in dopaminergic nigral neurons colocalized with neuromelanin. Overall GPX4 was significantly reduced in substantia nigra in Parkinson's vs. control subjects, but was increased relative to the cell density of surviving nigral cells. In putamen, GPX4 was concentrated within dystrophic dopaminergic axons in Parkinson's subjects, although overall levels of GPX4 were not significantly different compared to control putamen.</p> <p>Conclusions</p> <p>This study demonstrates an up-regulation of GPX4 in neurons of substantia nigra and association of this protein with dystrophic axons in striatum of Parkinson's brain, indicating a possible neuroprotective role. Additionally, our findings suggest this enzyme may contribute to the production of neuromelanin.</p