Digging in the Dirt and Keeping Research Clean: Bridging Two Majors with Hands‐on Work

With a double major in anthropology and Earth science, my research experiences include both archaeological field school in Belize and work in a clean lab. In field school I experienced what participating in a Maya dig is like: early mornings, long days in the tropical heat, the rewarding feeling of finding artifacts and making maps of the site, and finally, validating that archaeology is what I want to do. My more recent work in the clean lab has branched off from that field school experience. Throughout the summer of 2018 and the academic year that followed, I have been working to expand our knowledge of neodymium as a useful new method in archaeology. Specifically, I am aiming to improve the methods in which the provenance of ceramic artifacts can be attained. During my research I worked with clay samples taken from the Belize River Valley during the 2013–2014 field seasons by a previous University of New Hampshire student. I analyzed both the strontium isotopes, a method that is already used in archaeological research, and the neodymium isotopes, a method new to the archaeological field. My results will go toward a push to make neodymium isotopic analysis more common in the field and a database of known neodymium concentrations available for future archaeologists. Funded by a Summer Undergraduate Research Fellowship, this project has allowed me to combine both of my majors for my senior thesis and has set me up for a great beginning to my graduate career

Nanomedicine and Society

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110021/1/cptclpt2008276.pd

Plastic deformation of CoO single crystals

Constant strain rate compressions along have been performed on CoO single crystals (ε ∼ 6 x 10-5 s-1). Yield stresses and work hardening rates have been measured between 77 K and 1 400 K; CoO is very strong when compared to similar compounds. Vickers indentations have been performed on { 100 }, { 110 } and {111 } faces around the Néel temperature, i.e. between 0 °C and 40 °C. Hardness values are low if compared to constant strain rate deformation characteristics; they show a minor anomaly at the Néel temperature.Des essais de compression à vitesse constante (ε ∼ 6 x 10 -5 s-1) ont été réalisés selon une direction de monocristaux de CoO. La contrainte à la limite élastique et le taux de consolidation ont été déterminés entre 77 K et 1 400 K. Leurs valeurs sont très élevées par rapport à celles de composés similaires. La micro-dureté Vickers a été mesurée sur les faces { 100 }, { 110 } et { 111 } entre 0 °C et 40 °C, températures encadrant le point de Néel. La dureté de CoO est faible par comparaison avec les caractéristiques de déformation à vitesse constante; elle montre une faible anomalie à la température de Néel

Effects of Genotype and Child Abuse on DNA Methylation and Gene Expression at the Serotonin Transporter

Altered regulation of the serotonin transporter (SLC6A4) is hypothesized to be a key event in many forms of neuropsychiatric illness, yet our understanding of the molecular mechanisms through which changes in gene function could lead to illness remains incomplete. In prior studies, we and others have demonstrated that methylation of CpG residues in the promoter associated CpG island alters SLC6A4 gene expression, that the extent of that DNA methylation in child abuse is genotype dependent, and that adverse childhood experiences such as child sex abuse are related to methylation. However, we have not examined whether these effects are splice variant specific, whether the association of methylation to gene expression varies as a function of genotype, and whether methylation in other SLC6A4 gene regions are more likely candidates for GxE effects. In the current investigation we measured methylation in lymphoblast DNA from 158 female subjects in the Iowa Adoption Studies at 16 CpG residues spread across the SLC6A4 locus, and analyzed their relationship to gene expression for two SLC6A4 splice variants. Methylation of two CpG residues in the shore of the CpG island (cg22584138 and cg05951817), a location immediately upstream from exon 1A, predicted gene expression for the splice variant containing Exon 1A + 1B. Methylation at two residues in the CpG island itself (cg 25769822 and cg05016953) was associated with total SLC6A4 expression. Examination of these four CpG residues indicated that methylation of cg22584138 was influenced by both genotype and sex abuse, whereas methylation of cg05016953 was influenced only by sex abuse history. Factors influencing methylation at other CpG dinucleotide pairs were not identified. We conclude that methylation effects on transcription may vary as a function of underlying gene motif and splice variant, and that the shore of CpG islands, upstream of TSS, may be of particular interest in examining environmental effects on methylation

Valorization of surface-water RO brines via Assisted-Reverse Electrodialysis for minerals recovery: Performance analysis and scale-up perspectives

Reverse osmosis (RO) processes have been recently identified as mostly capable of quantitative removal of salts and contaminants from saline and surface waters, though posing the problem of a concentrated brine to be disposed of and a produced permeate too low in minerals, thus requiring a sometimes expensive remineralization step. In the present paper, Assisted-Reverse Electrodialysis (A-RED) has been proposed for the remineralization of surface-water RO permeate by recovering minerals from its brine. A purposely developed and validated model has been adopted to carry out a parametric analysis for design and optimization of an industrial-scale plant. The techno-economic analysis underlined that full permeate remineralization can be achieved with minimum specific energy consumption of 0.08 kWh m(-3), while a minimum remineralization cost of 2.2 c(sic) m(-3) was found applying a permeate by-pass and feed & bleed scheme to (i) increase the plant remineralization capacity and (ii) maintain a stack inlet conductivity above 100-160 mu S cm(-1) (starting from a permeate similar to 10 mu S cm(-1)). Compared to current post-treatment techniques, results appear very promising thanks to the reduction of chemicals and total costs as well as environmental concerns related to brine disposal

Calibration of thickness-dependent k-factors for germanium X-ray lines to improve energy-dispersive X-ray spectroscopy of SiGe layers in analytical transmission electron microscopy

We show that the accuracy of energy-dispersive X-ray spectroscopy can be improved by analysing and comparing multiple lines from the same element. For each line, an effective k-factor can be defined that varies as a function of the intensity ratio of multiple lines (e.g. K/L) from the same element. This basically performs an internal self-consistency check in the quantification using differently absorbed X-ray lines, which is in principle equivalent to an absorption correction as a function of specimen thickness but has the practical advantage that the specimen thickness itself does not actually need to be measured

Diffusion and jump-length distribution in liquid and amorphous Cu33_{33}Zr67_{67}

Using molecular dynamics simulation, we calculate the distribution of atomic jum ps in Cu$_{33}$Zr$_{67}$ in the liquid and glassy states. In both states the distribution of jump lengths can be described by a temperature independent exponential of the length and an effective activation energy plus a contribution of elastic displacements at short distances. Upon cooling the contribution of shorter jumps dominates. No indication of an enhanced probability to jump over a nearest neighbor distance was found. We find a smooth transition from flow in the liquid to jumps in the g lass. The correlation factor of the diffusion constant decreases with decreasing temperature, causing a drop of diffusion below the Arrhenius value, despite an apparent Arrhenius law for the jump probability

Self-organized transient facilitated atomic transport in Pt/Al(111)

During the course of atomic transport in a host material, impurity atoms need to surmount an energy barrier driven by thermodynamic bias or at ultra-low temperatures by quantum tunneling. In the present article we demonstrate using atomistic simulations that at ultra-low temperature transient inter-layer atomic transport is also possible without tunneling when the Pt/Al(111) impurity/host system self-organizes itself spontaneously into an intermixed configuration. No such extremely fast athermal concerted process has been reported before at ultra low temperatures. The outlined novel transient atomic exchange mechanism could be of general validity. We find that the source of ultra-low temperature heavy particle barrier crossing is intrinsic and no external bias is necessary for atomic intermixing and surface alloying in Pt/Al although the dynamic barrier height is few eV. The mechanism is driven by the local thermalization of the Al(111) surface in a self-organized manner arranged spontaneously by the system without any external stimulus. The core of the short lived thermalized region reaches the local temperature of $\sim 1000$ K (including few tens of Al atoms) while the average temperature of the simulation cell is $\sim 3$ K. The transient facilitated intermixing process also takes place with repulsive impurity-host interaction potential leading to negative atomic mobility hence the atomic injection is largely independent of the strength of the impurity-surface interaction. We predict that similar exotic behaviour is possible in other materials as well.Comment: 12 pages, 8 figures, full paper at: http://www.mfa.kfki.hu/~sule/papers/ptonal.pdf . J. Chem. Phys. (2008), in pres

Education and older adults at the University of the Third Age

This article reports a critical analysis of older adult education in Malta. In educational gerontology, a critical perspective demands the exposure of how relations of power and inequality, in their myriad forms, combinations, and complexities, are manifest in late-life learning initiatives. Fieldwork conducted at the University of the Third Age (UTA) in Malta uncovered the political nature of elder-learning, especially with respect to three intersecting lines of inequality - namely, positive aging, elitism, and gender. A cautionary note is, therefore, warranted at the dominant positive interpretations of UTAs since late-life learning, as any other education activity, is not politically neutral.peer-reviewe