Reanimating the tomb: Interpreting Palmyra’s banquet reliefs in context

This thesis focuses on banquet scenes from the tombs of Roman Palmyra, Syria – relief sculpture depicting the deceased reclining on a kline, surrounded by his family in a commemorative tableau of elite values. In response to the scattering of thousands of pieces of Palmyrene funerary sculpture in museums across the world, this research explores meaning in the reliefs as impacted by, and inherently tied to, its original funerary context. Taking a holistic approach, iconographic study of tomb sculpture and wall painting is utilized alongside analysis of grave goods and tomb architecture to build a fuller picture of eschatological belief and mortuary activity connected to these spaces. Closing with a case study of the Hypogeum of Bolha and Borrefa, the banquet reliefs within are presented as the centrepiece of a dynamic, sensory space in which multiple elements interact and contribute to the overall construction of meaning

Substituted Azolium Disposition: Examining the Effects of Alkyl Placement on Thermal Properties

We describe the thermal phase characteristics of a series of 4,5-bis(n-alkyl)azolium salts that were studied using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), polarized-light optical microscopy (POM), and synchrotron-based small- to wide-angle X-ray scattering (SWAXS) measurements. Key results were obtained for 1,3-dimethyl-4,5-bis(n-undecyl)imidazolium iodide (1-11), 1,3-dimethyl-4,5-bis(n-pentadecyl)imidazolium iodide (1-15), and 1,2,3-trimethyl-4,5-bis(n-pentadecyl)imidazolium iodide (2), which were found to adopt enantiotropic smectic A mesophases. Liquid-crystalline mesophases were not observed for 1,3-dimethyl-4,5-bis(n-heptyl)imidazolium iodide (1-7), 3-methyl-4,5-bis(n-pentadecyl)thiazolium iodide (3), and 2-amino-4,5-bis(n-pentadecyl)imidazolium chloride (4). Installing substituents in the 4- and 5-positions of the imidazolium salts appears to increase melting points while lowering clearing points when compared to data reported for 1,3-disubstituted analogues

Effect of Re-acidification on Buffalo Grass Rhizosphere and Bulk Microbial Communities During Phytostabilization of Metalliferous Mine Tailings

Phytostabilized highly acidic, pyritic mine tailings are susceptible to re-acidification over time despite initial addition of neutralizing amendments. Studies examining plant-associated microbial dynamics during re-acidification of phytostabilized regions are sparse. To address this, we characterized the rhizosphere and bulk bacterial communities of buffalo grass used in the phytostabilization of metalliferous, pyritic mine tailings undergoing re-acidification at the Iron King Mine and Humboldt Smelter Superfund Site in Dewey-Humboldt, AZ. Plant-associated substrates representing a broad pH range (2.35-7.76) were sampled to (1) compare the microbial diversity and community composition of rhizosphere and bulk compartments across a pH gradient, and (2) characterize how re-acidification affects the abundance and activity of the most abundant plant growth-promoting bacteria (PGPB; including N2-fixing) versus acid-generating bacteria (AGB; including Fe-cycling/S-oxidizing). Results indicated that a shift in microbial diversity and community composition occurred at around pH 4. At higher pH (>4) the species richness and community composition of the rhizosphere and bulk compartments were similar, and PGPB, such as Pseudomonas, Arthrobacter, Devosia, Phyllobacterium, Sinorhizobium, and Hyphomicrobium, were present and active in both compartments with minimal presence of AGB. In comparison, at lower pH (<4) the rhizosphere had a significantly higher number of species than the bulk (p < 0.05) and the compartments had significantly different community composition (unweighted UniFrac; PERMANOVA, p < 0.05). Whereas some PGPB persisted in the rhizosphere at lower pH, including Arthrobacter and Devosia, they were absent from the bulk. Meanwhile, AGB dominated in both compartments; the most abundant were the Fe-oxidizer Leptospirillum and Fe-reducers Acidibacter and Acidiphilium, and the most active was the Fe-reducer Aciditerrimonas. This predominance of AGB at lower pH, and even their minimal presence at higher pH, contributes to acidifying conditions and poses a significant threat to sustainable plant establishment. These findings have implications for phytostabilization field site management and suggest re-application of compost or an alternate buffering material may be required in regions susceptible to re-acidification to maintain a beneficial bacterial community conducive to long-term plant establishment.National Institute of Environmental and Health Sciences (NIEHS) Superfund Research Program (SRP) [P42 ES004940]; National Science Foundation Graduate Research Fellowhip Program (NSF GRFP) [DGE-1143953]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Resolving colocalization of bacteria and metal(loid)s on plant root surfaces by combining fluorescence in situ hybridization (FISH) with multiple-energy micro-focused X-ray fluorescence (ME μXRF)

Metal(loid)-contamination of the environment due to anthropogenic activities is a global problem. Understanding the fate of contaminants requires elucidation of biotic and abiotic factors that influence metal(loid) speciation from molecular to field scales. Improved methods are needed to assess micro-scale processes, such as those occurring at biogeochemical interfaces between plant tissues, microbial cells, and metal(loid)s. Here we present an advanced method that combines fluorescence in situ hybridization (FISH) with synchrotron-based multiple-energy micro-focused X-ray fluorescence microprobe imaging (ME pXRF) to examine colocalization of bacteria and metal(loid)s on root surfaces of plants used to phytostabilize metalliferous mine tailings. Bacteria were visualized on a small root section using SytoBC nucleic acid stain and FISH probes targeting the domain Bacteria and a specific group (Alphaproteobacteria, Gammaproteobacteria, or Actinobacteria). The same root region was then analyzed for elemental distribution and metal(loid) speciation of As and Fe using ME pXRF. The FISH and ME pXRF images were aligned using Image.' software to correlate microbiological and geochemical results. Results from quantitative analysis of colocalization show a significantly higher fraction of As colocalized with Fe-oxide plaques on the root surfaces (fraction of overlap 0.49 +/- 0.19) than to bacteria (0.072 +/- 0.052) (p < 0.05). Of the bacteria that colocalized with metal(loid)s, Actinobacteria, known for their metal tolerance, had a higher correlation with both As and Fe than Alphaproteobacteria or Gammaproteobacteria. This method demonstrates how coupling these micro-techniques can expand our understanding of micro-scale interactions between roots, metal(loid)s and microbes, information that should lead to improved mechanistic models of metal(loid) speciation and fate. (C) 2016 Elsevier B.V. All rights reserved.National Institute of Environmental Health Sciences (NIEHS) Superfund Research Program (SRP) [P42 ES04940, R01 ES1709]; National Science Foundation Graduate Research Fellowhip Program (NSF GRFP) [DGE-1143953]; U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-765F00515]12 month embargo; published online: 29 September 2016This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Self-assembly of liquid crystal block copolymer PEG-b-smectic polymer in pure state and in dilute aqueous solution

A series of amphiphilic LC block copolymers, in which the hydrophobic block is a smectic polymer poly(4-methoxyphenyl 4-(6-acryloyloxy-hexyloxy)-benzoate) (PA6ester1) and the hydrophilic block is polyethyleneglycol (PEG), were synthesized and characterized. The self-assembly of one of them in both the pure state and the dilute aqueous solution was investigated in detail. Nano-structures in the pure state were studied by SAXS and WAXS on samples aligned by a magnetic field. A hexagonal cylindrical micro-segregation phase was observed with a lattice distance of 11.2 nm. The PEG blocks are in the cylinder, while the smectic polymer blocks form a matrix with layer spacing 2.4 nm and layer normal parallel to the long axis of the cylinders. Faceted unilamellar polymer vesicles, polymersomes, were formed in water, as revealed by cryo-TEM. In the lyotropic bilayer membrane of these polymersomes, the thermotropic smectic order in the hydrophobic block is clearly visible with layer normal parallel to the membrane surface

Bacterial Rhizoplane Colonization Patterns of Buchloe dactyloides Growing in Metalliferous Mine Tailings Reflect Plant Status and Biogeochemical Conditions

Plant establishment during phytostabilization of legacy mine tailings in semiarid regions is challenging due to low pH, low organic carbon, low nutrients, and high toxic metal(loid) concentrations. Plant-associated bacterial communities are particularly important under these harsh conditions because of their beneficial services to plants. We hypothesize that bacterial colonization profiles on rhizoplane surfaces reflect deterministic processes that are governed by plant health and the root environment. The aim of this study was to identify associations between bacterial colonization patterns on buffalo grass (Buchloe dactyloides) rhizoplanes and both plant status (leaf chlorophyll and plant cover) and substrate biogeochemistry (pH, electrical conductivity, total organic carbon, total nitrogen, and rhizosphere microbial community). Buffalo grass plants from mesocosm- and field-scale phytostabilization trials conducted with tailings from the Iron King Mine and Humboldt Smelter Superfund Site in Dewey-Humboldt, Arizona, were analyzed. These tailings are extremely acidic and have arsenic and lead concentrations of 2-4 g kg-1 substrate. Bacterial communities on rhizoplanes and in rhizosphere-associated substrate were characterized using fluorescence in situ hybridization and 16S rRNA gene amplicon sequencing, respectively. The results indicated that the metabolic status of rhizoplane bacterial colonizers is significantly related to plant health. Principal component analysis revealed that root-surface Alphaproteobacteria relative abundance was associated most strongly with substrate pH and Gammaproteobacteria relative abundance associated strongly with substrate pH and plant cover. These factors also affected the phylogenetic profiles of the associated rhizosphere communities. In summary, rhizoplane bacterial colonization patterns are plant specific and influenced by plant status and rhizosphere biogeochemical conditions.National Institute of Environmental and Health Sciences (NIEHS) Superfund Research Program (SRP) [P42 ES004940, R01 ES01709]; National Science Foundation Graduate Research Fellowhip Program (NSF GRFP) [DGE-1143953]12 month embargo; published online: 2 June 2017This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Magnetization of coupled spin clusters in Ladder Geometry

In this paper, we construct a class of spin-1/2 antiferromagnetic (AFM) two-chain ladder models consisting of blocks of n-spin tetrahedral clusters alternating with two-spin rungs. For n=4 and 6 and in extended parameter regimes, the exact ground state of the ladder is shown to be a product of the ground states of the rungs and the n-spin blocks, in both zero and finite magnetic fields. In the latter case, magnetization/site (m) versus magenetic field (h) plot exhibits well-defined magnetization plateaus.Comment: 9 pages, latex, 6 figures, To be published in Phys. Rev.

Ciudades Inteligentes y Desempleo Juvenil: La Tecnología Móvil como Herramienta de Conexión de Oferta y Demanda Laboral

La Ciudad de Buenos Aires es frecuentemente identificada como una ciudad inteligente – al menos en el contexto regional –, particularmente en las dimensiones de gobernanza y proyección internacional. Pero es claro que queda mucho por hacer para seguir avanzando en distintos aspectos que hacen de una ciudad un centro urbano inteligente. Uno de los sectores en los cuales la ciudad ha avanzado en cuanto a implementación de enfoques de arriba hacia abajo (top-down) es la lucha contra el desempleo. El gobierno local cuenta con numerosos programas de capacitación y búsqueda de empleo para residentes de todas las edades. Sin embargo, estos programas se caracterizan por la falta de una plataforma amigable al usuario final que incorpore la tecnología móvil como principal medio de acceso. ¿Cómo podemos extender el concepto de ciudad inteligente a las políticas de empleo en la Ciudad? Y, más precisamente, ¿qué herramientas son más útiles para hacer los programas de capacitación y búsqueda ya existentes más eficientes y accesibles para quienes se encuentran en situación de desempleo, particularmente los jóvenes? Este trabajo se propone aplicar el concepto de ciudad inteligente a la problemática del desempleo juvenil en la Ciudad de Buenos Aires. Si bien el gobierno local cuenta con numerosas ofertas cuyo fin es luchar contra el desempleo joven e incrementar el capital humano, estas aún no han aprovechado al máximo las nuevas tecnologías, particularmente la tecnología móvil traducida en el aumento exponencial del uso de smartphones entre la población joven de todos los segmentos socioeconómicos. Basándome en el concepto de ciudad inteligente y en el foco en el usuario (o ciudadano) vía el uso de tecnología móvil, este trabajo ofrece una propuesta de política pública que apunta a mejorar la eficacia de los programas pro-empleo ya existentes en la Ciudad de Buenos Aires