Shellfish Tissue Monitoring in Piscataqua Region Estuaries 2010 and 2011

Conducted by a committee of Canadian and US government and university scientists, Gulfwatch examines the effects of decades of development and industrialization on the water quality of the Gulf as it relates to human health primarily through assessing contaminant exposure of marine organisms. Gulfwatch scientists collect blue mussels at over 60 US and Canadian sites Gulfwide, and analyze the organisms’ tissue for potentially harmful levels and concentrations of toxins including heavy metals, chlorinated pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs)

Shellfish Tissue Monitoring in Piscataqua Region Estuaries 2013

Originally conducted by the Gulf of Maine Council on the Marine Environment from 1993 to 2011, the Gulfwatch Program examined trends in the water quality of the Gulf of Maine by monitoring toxic contaminant concentrations in the tissues of shellfish. Starting in 2012 the Piscataqua Region Estuaries Partnership (PREP) continued this program in the Piscataqua Region. Each year, PREP collects blue mussels at three sites: Dover Point, NH (NHDP), Clark Cove on Seavey Island, ME (MECC), and Hampton-Seabrook Harbor (NHHS). The mussel tissue is analyzed to determine the concentrations of toxic contaminantss including heavy metals, chlorinated pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs)

Shellfish Tissue Monitoring in Piscataqua Region Estuaries 2010: Final Report

Gulfwatch examines the effects of decades of development and industrialization on the water quality of the Gulf as it relates to human health primarily through assessing contaminant exposure of marine organisms. Gulfwatch scientists collect blue mussels at over 60 US and Canadian sites Gulfwide, and analyze the organisms’ tissue for potentially harmful levels and concentrations of toxins including heavy metals, chlorinated pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). New Hampshire increased the number of Gulfwatch sampling locations from two sites per year in 1997 to an average of five sites per year from 1998-2010. The increased spatial coverage provides comprehensive information for contaminant concentrations throughout the New Hampshire estuarine waters. All samples collected for the Gulfwatch monitoring program, from the Canadian provinces as well as the New England states involved, have been sent to the same laboratories for analysis. All of the samples have been analyzed at the same time in the same laboratories in an effort to reduce error and variability. This practice has ensured the consistency that was necessary to allow a region-wide assessment of the health of the Gulf. During the 2010 sampling season, mussels were collected at six sampling locations in New Hampshire and Maine (MECC, NHHS, NHDP, NHRH, NHPI and NHLH). Project Goals and Objectives The goal of this project was to provide data for two PREP indicators of estuarine condition: TOX1 and TOX3. These two indicators report on “Shellfish tissue concentrations relative to FDA standards” and “Trends in shellfish tissue contaminant concentrations”, respectively. Both of these indicators depend on data from the Gulfwatch Program. In particular, TOX3 requires annual data at benchmark sites to assess trends. In 2010, PREP supported the collection and analysis of tissue samples from benchmark mussel sites in Hampton-Seabrook Harbor and Dover Point

Shellfish Tissue Monitoring in Piscataqua Region Estuaries 2012

Originally conducted by a committee of Canadian and US governments and university scientists, Gulfwatch examined the effects of decades of development and industrialization on the water quality of the Gulf of Maine as it relates to human health primarily through assessing contaminant exposure of marine organisms from 1993 to 2010. The NH Gulfwatch Program continues these efforts by collecting blue mussels at two sites in the Great Bay Estuary and one in the Hampron-Seabrook Estuary, and analyzes the organisms’ tissue for potentially harmful levels and concentrations of toxins including heavy metals, chlorinated pesticides, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). During the 2012 sampling season, mussels were collected at three sampling locations in New Hampshire and Maine (MECC, NHHS and NHDP)

Order and Disorder in Type–II InAs/InAsSb Superlattices

We employ cross–sectional scanning tunneling microscopy (STM) to examine how an as–grown InAs/InAsSb superlattice differs from the intended one as regards translational invariance in (001) planes perpendicular to the growth direction. This requires atomic–resolution, lateral surveys paralleling the buffer/epilayer interface for up to a micron in orthogonal (–1–10) or (1–10) cross sections, together with repeated lateral surveys at representative vertical locations (i.e., spanned superlattice repeats) within the multilayer stack. We show that STM may be used to accurately map the period fluctuations throughout this superlattice. The concept, analogous to Bragg's law in high–resolution x–ray diffraction, relies on an analysis of the [001]–convolved reciprocal–space satellite peaks obtained from discrete Fourier transforms of individual STM images. Properly implemented, the technique enables local period measurements that reliably discriminate lateral fluctuations localized to within ~ 40 nm along directions in the growth plane. While not as accurate as x–ray, the inherent, single–image measurement error associated with the method may be made as small as 0.1%, allowing the lateral period fluctuations contributing to inhomogeneous energy broadening and carrier localization in these structures to be pinpointed and quantified. The direct visualization of unexpectedly–large fluctuations on nanometer length scales is tied to a stochastic description of correlated interface roughness. We also introduce a new technique to automatically tabulate the crystalline coordinates of previously–identified top–layer antimony atoms and construct the antimony pair–correlation functions for orthogonal cross sections. Nearest–neighbor correlations on opposing cleavage faces are inversely related, with the (–1–10) deficit at nearest–neighbor sites balanced by a compensating (1–10) surplus. The logarithm of this preference scales inversely with bulk antimony fraction. In more vivid physical terms, the preferential [110]–incorporation of nearest–neighbor antimony atoms in the bulk is traced to the inferred concentration of [110]–oriented antimony dimers at the growth surfac

Shellfish Tissue Monitoring in Piscataqua Region Estuaries 2010 and 2011

The goal of this project was to provide data for two PREP indicators of estuarine condition: TOX1 and TOX3. These two indicators report on “Shellfish tissue concentrations relative to FDA standards” and “Trends in shellfish tissue contaminant concentrations”, respectively. Both of these indicators depend on data from the Gulfwatch Program. In particular, TOX3 requires annual data at benchmark sites to assess trends. In 2010 and 2011, PREP supported the collection and analysis of tissue samples from benchmark mussel sites in Hampton-Seabrook Harbor and Dover Point

Near-Shortest and K-Shortest Simple Paths

2005, Networks, 46, pp. 98-109

Search for Gamma-ray Emission from Dark Matter Annihilation in the Small Magellanic Cloud with the Fermi Large Area Telescope

The Small Magellanic Cloud (SMC) is the second-largest satellite galaxy of the Milky Way and is only 60 kpc away. As a nearby, massive, and dense object with relatively low astrophysical backgrounds, it is a natural target for dark matter indirect detection searches. In this work, we use six years of Pass 8 data from the Fermi Large Area Telescope to search for gamma-ray signals of dark matter annihilation in the SMC. Using data-driven fits to the gamma-ray backgrounds, and a combination of N-body simulations and direct measurements of rotation curves to estimate the SMC DM density profile, we found that the SMC was well described by standard astrophysical sources, and no signal from dark matter annihilation was detected. We set conservative upper limits on the dark matter annihilation cross section. These constraints are in agreement with stronger constraints set by searches in the Large Magellanic Cloud and approach the canonical thermal relic cross section at dark matter masses lower than 10 GeV in the $b\bar{b}$ and $\tau^+\tau^-$ channels.Comment: 17 pages, 11 figures. Accepted by PR

Mints not Mines: a macroscale investigation of Roman silver coinage

Although silver coins have been investigated through the lens of geological provenance to locate argentiferous ore deposits exploited in their production, we consider that this avenue of research may be a cul-de-sac, especially for studies that rely heavily on deciphering lead and silver isotope signatures that may have been altered by the addition of lead and copper (and their associated impurities) during silver refining and debasement, and by ancient recycling of coinage. Instead, we focus our attention on mints, by analysing the compositions of over 1000 silver coins from the early 1st century BC to AD 100. We propose that lead from the west Mediterranean was used exclusively to refine silver at mints in the West, and that an unknown lead supply (possibly from Macedonia), used in the East by the Late Seleucid ruler Philip I Philadelphus and later Mark Antony, was mixed with western lead. Extensive mixing of lead and/or silver coins is particularly evident under Nero and Vespasian, aligning with historically attested periods of recycling following currency reform. We further propose that coins minted in the kingdom of Mauretania used different lead and silver sources from the majority of coins minted in the western Mediterranean, and that silver coins minted at Tyre are derived from silver refined in the west Mediterranean. Coinage minted at Alexandria is consistent with debasement of recycled Roman denarii, thereby suggesting that denarii were deliberately removed from circulation to mint tetradrachms during the early Imperial Roman period