Storm-driven sediment transport in Massachusetts Bay

This paper is not subject to U.S. copyright. The definitive version was published in Continental Shelf Research 28 (2008): 257-282, doi:10.1016/j.csr.2007.08.008.Massachusetts Bay is a semi-enclosed embayment in the western Gulf of Maine about 50 km wide and 100 km long. Bottom sediment resuspension is controlled predominately by storm-induced surface waves and transport by the tidal- and wind-driven circulation. Because the Bay is open to the northeast, winds from the northeast (‘Northeasters’) generate the largest surface waves and are thus the most effective in resuspending sediments. The three-dimensional oceanographic circulation model Regional Ocean Modeling System (ROMS) is used to explore the resuspension, transport, and deposition of sediment caused by Northeasters. The model transports multiple sediment classes and tracks the evolution of a multilevel sediment bed. The surficial sediment characteristics of the bed are coupled to one of several bottom-boundary layer modules that calculate enhanced bottom roughness due to wave–current interaction. The wave field is calculated from the model Simulating WAves Nearshore (SWAN). Two idealized simulations were carried out to explore the effects of Northeasters on the transport and fate of sediments. In one simulation, an initially spatially uniform bed of mixed sediments exposed to a series of Northeasters evolved to a pattern similar to the existing surficial sediment distribution. A second set of simulations explored sediment-transport pathways caused by storms with winds from the northeast quadrant by simulating release of sediment at selected locations. Storms with winds from the north cause transport southward along the western shore of Massachusetts Bay, while storms with winds from the east and southeast drive northerly nearshore flow. The simulations show that Northeasters can effectively transport sediments from Boston Harbor and the area offshore of the harbor to the southeast into Cape Cod Bay and offshore into Stellwagen Basin. This transport pattern is consistent with Boston Harbor as the source of silver found in the surficial sediments of Cape Cod Bay and Stellwagen Basin.We gratefully acknowledge support from the USGS Mendenhall Post-Doctoral Research Program for John C. Warner

Evidence of antineutrinos from distant reactors using pure water at SNO

The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240 km away in Ontario, Canada. This analysis uses events with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5σ

Improved search for invisible modes of nucleon decay in water with the SNO+ detector

This paper reports results from a search for single and multi-nucleon disappearance from the $^{16}$O nucleus in water within the \snoplus{} detector using all of the available data. These so-called "invisible" decays do not directly deposit energy within the detector but are instead detected through their subsequent nuclear de-excitation and gamma-ray emission. New limits are given for the partial lifetimes: $\tau(n\rightarrow inv) > 9.0\times10^{29}$ years, $\tau(p\rightarrow inv) > 9.6\times10^{29}$ years, $\tau(nn\rightarrow inv) > 1.5\times10^{28}$ years, $\tau(np\rightarrow inv) > 6.0\times10^{28}$ years, and $\tau(pp\rightarrow inv) > 1.1\times10^{29}$ years at 90\% Bayesian credibility level (with a prior uniform in rate). All but the ($nn\rightarrow inv$) results improve on existing limits by a factor of about 3.info:eu-repo/semantics/publishedVersio

Observation of Antineutrinos from Distant Reactors using Pure Water at SNO+

The SNO+ collaboration reports the first observation of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240 km away in Ontario, Canada. This analysis used events with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods were used to distinguish reactor antineutrinos from background events in 190 days of data and yielded consistent observations of antineutrinos with a combined significance of 3.5 $\sigma$.Comment: v2: add missing author, add link to supplemental materia

The tobacco splitworm /

no.59 (1914

Estrogen and soy isoflavonoids decrease sensitivity of medulloblastoma and central nervous system primitive neuroectodermal tumor cells to chemotherapeutic cytotoxicity

Abstract Background Our previous studies demonstrated that growth and migration of medulloblastoma (MB), the most common malignant brain tumor in children, are stimulated by 17β-estradiol. The growth stimulating effects of estrogens are mediated through ERβ and insulin-like growth factor 1 signaling to inhibit caspase 3 activity and reduce tumor cell apoptosis. The objective of this study was to determine whether estrogens decreased sensitivity of MB cells to cytotoxic actions of chemotherapeutic drugs. Methods Using in vitro cell viability and clonogenic survival assays, concentration response analysis was used to determine whether the cytoprotective effects of estradiol protected human D283 Med MB cells from the cytotoxic actions of the MB chemotherapeutic drugs cisplatin, vincristine, or lomustine. Additional experiments were done to determine whether the ER antagonist fulvestrant or the selective ER modulator tamoxifen blocked the cytoprotective actions of estradiol. ER-selective agonists and antagonists were used to define receptor specificity, and the impacts of the soy-derived phytoestrogens genistein, daidzein, and s-equol on chemosensitivity were evaluated. Results In D283 Med cells the presence of 10 nM estradiol increased the IC50 for cisplatin-induced inhibition of viability 2-fold from ~5 μM to >10 μM. In clonogenic survival assays estradiol decreased the chemosensitivity of D283 Med cells exposed to cisplatin, lomustine and vincristine. The ERβ selective agonist DPN and low physiological concentrations of the soy-derived phytoestrogens genistein, daidzein, and s-equol also decreased sensitivity of D283 Med cells to cisplatin. The protective effects of estradiol were blocked by the antiestrogens 4-hydroxytamoxifen, fulvestrant (ICI 182,780) and the ERβ selective antagonist PPHTP. Whereas estradiol also decreased chemosensitivity of PFSK-1 cells, estradiol increased sensitivity of Daoy cell to cisplatin, suggesting that ERβ mediated effects may vary in different MB celltypes. Conclusions These findings demonstrate that E2 and environmental estrogens decrease sensitivity of MB to cytotoxic chemotherapeutics, and that ERβ selective and non-selective inhibition of estrogen receptor activity blocks these cytoprotective actions. These findings support the therapeutic potential of antiestrogen adjuvant therapies for MB, and findings that soy phytoestrogens also decrease sensitivity of MB cells to cytotoxic chemotherapeutics suggest that decreased exposure to environmental estrogens may benefit MB patient responses to chemotherapy

Storm activity in ancient climates 2. An analysis using climate simulations and sedimentary structures.

Severe storms generate sedimentary structures and textures that can be identified in the geologic record. A companion paper [PSUCLIM, this issue] describes the genesis and distribution of both winter storms and hurricanes and their sensitivity to climatic and geographic variables. In this paper, a total of 90 storm deposits are compared to GENESIS climate simulations in order to examine storm activity from the Permian to the Cretaceous and to evaluate the ability of the model to predict storms in ancient environments. Approximately 70% of the observed deposits are predicted by the models. The majority of the missed deposits are associated with recognizable errors. If these specific sources of error are eliminated, the model predicts over 90% of observed deposits. This degree of accuracy allows the assignment of generative processes to individual deposits; however, causative differences between hummocky cross stratification and tempestite type deposits are not distinguishable. The distribution of severe storms through Earth history varies as a function of both continental geometry and climate. Elevated atmospheric CO2 appears to homogenize the latitudinal distribution of storm deposits by expanding the area of hurricane genesis. Geography exerted the dominant control on winter storm distribution and was responsible for a shift in the concentration of winter storm deposits from the Southern Hemisphere in the Early Permian to the Northern Hemisphere in the mid-Cretaceous.Anna M. Agustsdottir, Eric J. Barron, Karen L. Bice, Lee A. Colarusso, Janette L. Cookman, Brian A. Cosgrove, Jennifer L. De Lurio, Jan F. Dutton, Brent J. Frakes, Lawrence A. Frakes, Carmen J. Moy, Thomas D. Olszewski, Richard D. Pancost, Christopher J. Poulsen, Charles M. Ruffner, Douglas G. Sheldon, and Timothy S. White

Storm activity in ancient climates:1. Sensitivity of severe storms to climate forcing factors on geologic timescales

Severe storms are important agents of sediment transport, and they generate sedimentary structures and textures that can be identified in the geologic record. The genesis and the distribution of storms are associated with distinctive meteorological controls, which in many cases lend themselves to analysis using general circulation models of the atmosphere. The goal of this study is to predict the distribution of severe storms in Earth history and to evaluate the correspondence between climate model predictions and geologic observations for widely different past climate conditions. The first step toward achieving this goal is an assessment of the importance of different climatic forcing factors, including paleogeography, topography, solar luminosity, carbon dioxide concentrations, and ocean heat transport variations. This assessment is based on sensitivity experiments using the GENESIS general circulation model. Paleogeography plays the most important role in governing the distribution of winter storms and plays a major role in hurricane genesis and steering. In contrast, changes in carbon dioxide, ocean heat transport, and solar luminosity exhibit little influence on the distribution of winter storms or the steering of hurricanes. However, these factors influence the strength of winter storms and the area and frequency of hurricane generation. The relationships between climatic forcing factors and storm genesis and distribution provide considerable guidance in comparisons of model predictions with observations of severe storms in Earth history and for the interpretations of storm deposits. The comparison of model predictions to the geologic record is the subject PSUCLIM 2 [this issue]