Hadron Chemistry at High-PT with Identified Particles

We discuss mechanisms that change the hadron chemistry for high momentum particles emitted in high energy nuclear collisions. We argue that particle ratios naturally tend to be different from jets in the vacuum. We show results of computations in a model that propagates leading particles through a quark gluon plasma and permits elastic flavor changing processes. We predict less suppression for kaons compared to pions in central collision. We also discuss elliptic flow resulting from flavor changing processes.Comment: Report for CIPANP 2009; 4 pages, 4 figures, AIP style files include

Hadronization of Dense Partonic Matter

The parton recombination model has turned out to be a valuable tool to describe hadronization in high energy heavy ion collisions. I review the model and revisit recent progress in our understanding of hadron correlations. I also discuss higher Fock states in the hadrons, possible violations of the elliptic flow scaling and recombination effects in more dilute systems.Comment: 8 pages, 4 figures; plenary talk delivered at SQM 2006, to appear in J. Phys.

Relationships between Rooting Restrictions, Radial Growth, and Drought Stress with White Pine (Pinus strobus) Decline in Southern Maine

Throughout southern Maine there was a noticeable decline and mortality of white pine (Pinus sfrobus) from 1997 through 2000 in dense pole-size stands. The decline was widespread, scattered, and happened simultaneously indicating that it was incited by an abiotic stress. Because only isolated stands showed decline and mortality, site factors likely predisposed trees to injury. Site factors are likely related to the widespread field abandonment that took place throughout southern and central Maine, and led to establishment of pure white pine stands in many areas. Although white pine can regenerate on many sites, some locations will have soil limitations, such as plow plans and lithological discontinuities that cause white pine roots to spread more horizontally. A shallow root system would result in less water being available to a tree during a drought. The first hypothesis is that soil rooting restrictions predisposed the white pine to water stress inciting decline and mortality. The second hypothesis follows that the drought event occurred prior to 1997-2000, the period of white pine mortality. Paired sites, consisting of one high and one low mortality site, were evaluated in nine locations in Maine south of 45 N latitude in the towns of Wells, Lebanon, Hollis, Limington, Casco, Nobleboro, Massabesic, New Gloucester and Oxford. Tree species, crown class, crown condition, and diameter at breast height (DBH) were recorded at each stand. Two cores were removed from each dominant and codominant white pine, including dead trees, for dendrochronological analysis. Crossdating of cores was used to calculate the percentage of dead trees with the last growth ring in a given calendar year. Average annual increments between dead and surviving trees were compared on each high mortality site using mean ring widths. Potential rooting depth was measured in each site. Stream flow, precipitation, temperature, and Palmer Drought Severity Index (PDSI) were used with the program PRECON to look at long tern relationships between climate and growth

Understanding the Barriers to the Assimilation of Interorganizational Technologies in Channel Relationships

Organizations are increasingly focusing on their value chain activities in an effort to improve their performance, especially in the recent economic times. Improving the effectiveness and efficiency of their channel activities has become a focal point for many organizations. Interorganizational systems (IOS’s) have played an important part in this effort. While in theory, IOS’s have the ability to enhance the degree of cooperation and coordination between two channel partners, often the results obtained are not what is expected. Hence, it becomes very important to understand the barriers to the assimilation of these technologies. Drawing upon theoretical perspectives of governance, including transaction cost analysis (TCA), control theory and agency theory, we develop an integrative model that examines the factors that influence an organizations assimilation process. The model identifies and examines three stages of assimilation: technological, exploitive and explorative assimilation that add value to an organization. The model features asset specificity, technological uncertainty, performance documentation, agent orientation and bilateral governance mechanisms as antecedents to assimilation. It also examines the moderating effects of bilateral mechanisms. Our results suggest that theories of governance provide an additional lens to examine assimilation phenomena. In specific, our empirical analysis leads to several key findings: (1) channel partners who are locked in to the relationship with high levels of asset specificity are more likely to assimilate the technology; (2) bilateral governance mechanisms are a key force in the assimilation process, with both direct and moderated effects; (3) organizations that view the channel partner as an agent of the firm are less likely to adopt the technology, especially when the relationship exhibits low levels of bilateral governance mechanisms. Together these findings provide new insights into barriers to the assimilation of IOS’s in channel relationships

The Epidemiology of Multiple Sclerosis in Scotland: Inferences from Hospital Admissions

PMCID: PMC3029296This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Scanning micro-raman spectroscopy on carbon-rich residues of primitive chondrites: A tool for chondrite classification and stardust analysis

We present results obtained by Raman spectroscopy of various organic residues of primitive chondrites in order to better characterize the microstructural state of the organic matter. These results will be correlated with the petographic classification of the chondrites

Azimuthal Asymmetry of Direct Photons in High Energy Nuclear Collisions

We show that a sizeable azimuthal asymmetry, characterized by a coefficient v_2, is to be expected for direct photons produced in non-central high energy nuclear collisions. This signal is generated by photons radiated by jets interacting with the surrounding hot plasma. The anisotropy is out of phase by an angle $\pi/2$ with respect to that associated with the elliptic anisotropy of hadrons, leading to negative values of v_2. Such an asymmetry, if observed, could be a signature for the presence of a quark gluon plasma and would establish the importance of jet-plasma interactions as a source of electromagnetic radiation.Comment: New title. Final versio

Rapid Classification of Ordinary Chondrites Using Raman Spectroscopy

Classification of ordinary chondrites is typically done through measurements of the composition of olivine and pyroxenes. Historically, this measurement has usually been performed via electron microprobe, oil immersion or other methods which can be costly through lost sample material during thin section preparation. Raman microscopy can perform the same measurements but considerably faster and with much less sample preparation allowing for faster classification. Raman spectroscopy can facilitate more rapid classification of large amounts of chondrites such as those retrieved from North Africa and potentially Antarctica, are present in large collections, or are submitted to a curation facility by the public. With development, this approach may provide a completely automated classification method of all chondrite types

Everyone Wins: A Mars-Impact Origin for Carbonaceous Phobos and Deimos

Discussions of Phobos' and Deimos' origin(s) tend to feature an orthogonally opposed pair of observations: dynamical studies which favor coalescence of the moons from an orbital debris ring arising from a large impact on Mars; and reflectance spectroscopy of the moons that indicate a carbonaceous composition that is not consistent with Martian surface materials. One way to reconcile this discrepancy is to consider the option of a Mars-impact origin for Phobos and Deimos, followed by surficial decoration of carbon-rich materials by interplanetary dust particles (IDP). The moons experience a high IDP flux because of their location in Mars' gravity well. Calculations show that accreted carbon is sufficient to produce a surface with reflectance spectra resembling carbonaceous chondrites

Meteoritic Material Recovered from the 07 March 2018 Meteorite Fall into the Olympic Coast National Marine Sanctuary

On 07 March 2018 at 20:05 local time (08 March 03:05 UTC), a dramatic meteor occurred over Olympic Coast National Marine Sanctuary (OCNMS) off of the Washington state coast (OCNMS fall, henceforth). Data to include seismometry (from both on-shore and submarine seismometers), weather radar imagery (Figure 1), and a moored weather buoy, were used to accurately identify the fall site. The site was visited by the exploration vessel E/V Nautilus (Ocean Exploration Trust) on 01 July 2018 [1] and by the research vessel R/V Falkor (Schmidt Ocean Institute) from 03-06 June 2019. Remotely operated vehicles (ROVs) from both vessels were used to search for meteorites and sample seafloor sediments. These expeditions performed the first attempts to recover meteorites from a specific observed fall in the open ocean. Analysis of weather radar data indicates that this fall was unusually massive and featured meteorites of unusually high mechanical toughness, such that large meteorites were disproportionately produced compared to other meteorite falls (Figure 2)[2-4]. We report the recovery of many (>100) micrometeorite-sized melt spherules and other fragments, and one small (~1mm3 ) unmelted meteorite fragment identified to date. Approximately 80% of the fragments were recovered from a single sample, collected from a round pit in the seafloor sediment. Melt spherules are almost exclusively type I iron-rich spherules with little discernible oxidation. Analyses are currently underway to attempt to answer the primary science question by identifying the parent meteorite type. Also, differences in the number and nature of samples collected by Nautilus and Falkor reveal a distinct loss rate to oxidation over the 15 months following the fall that is useful to inform future recovery efforts