Suspended Alexandrium Spp. Hypnozygote Cysts in the Gulf of Maine

Hypnozygote cysts are a known stage in the life cycle of Alexandrium spp. Negatively buoyant cysts purportedly fall ,to the benthos where they undergo mandatory quiescence until their endogenous clock makes germination possible. If oxygen is present and the endogenous clock allows, germination will occur at a rate proportional to light and temperature. Offshore in the Gulf of Maine, where Alexandrium blooms are well documented, the paradigm of benthic cysts is problematic. Sediment surveys have found wide distribution of cysts, with highest cyst concentrations below 100 m in areas where deposition is favored. Germination at these depths is likely slow due to light inhibition; negative effects of burial on germination rate, and losses of cells during the transit from benthos to photic zone also present problems. The purpose of this study was to determine if cysts are suspended in the water column where they would be better positioned to initiate springtime Alexandrium populations. During cruises in February, April, and June of 2000, thirty liter samples were taken from the near-bottom, the top of the bottom nepheloid layer, and near surface, concentrated and stained with primulin for examination using epifluorescence microscopy. Suspended cysts were found widely distributed throughout the Gulf of Maine and Bay of Fundy. Generally, cysts were more abundant in near-bottom and top of the bottom nepheloid layer samples than in the surface.\u27 Alexandrium hypnozygote cysts were most abundant in February and least abundant in April. As a first order assessment of the potential for planktonic cysts relative to benthic cysts to initiate springtime populations of Alexandrium vegetative cells, the following rough calculation was performed using as an example the data from the Bay of Fundy in February. In February planktonic cysts numbered on the order of lo2 cysts m in surface waters in the Bay of Fundy; near bottom cyst concentrations were between lo2 - lo3 cysts m . Roughly integrating total suspended cysts yields lo4 cysts m-2. Cysts in the Bay of Fundy sediments were found at concentrations of lo3 cysts ~ m - ~ . Conservatively, only the uppermost 1 rnm layer of cysts will be able to successfully geminate, which equals lo2 cysts cm-2 or lo6 cysts m-2. Studies have shown that only 10 % of benthic cysts germinate and that light enhances germination rate 10-fold, which lowers the benthic estimate to lo4 cysts m-2, the same concentration as found in the water column. The purpose of this study was primarily to determine the presence or absence of Alexandriurn hypnozygote cysts in the water column in the Gulf of Maine. The data, while significant in that they show the presence of potentially important cyst in the water, do not lend themselves well to robust statistical analysis. However, this study provides evidence that suspended cysts likely contribute significantly to spring Alexandrium populations. Suspended cysts should be considered in future investigations and computer modeling designed to predict Alexandrium caused paralytic shellfish poisoning events

The Power of Invitation: Teacher Leaders as Agents of Change

Programs offered by universities and other entities outside the organizational boundaries of schools are an important source of ideas and support for educational improvement. Such organizations can focus on important needs—such as improving teaching of science—that schools perhaps cannot address on their own due to resource constraints. In such cases, teacher leaders can play key roles in bringing the knowledge and insights from external organizations into schools, sharing them with colleagues, and gaining administrative support. This kind of teacher leadership, responding to external initiatives rather than just to administrative priorities, is understudied, but programs in Maine that connect schools to universities and nonprofit organizations provide insight into the nature of such teacher leadership. We draw upon cases from two of these programs to offer suggestions to other organizations that might wish to develop programs for teacher leaders in support of educational improvement

Community Science’s Contributions to Fostering Relational Values to Overcome Coastal Ecosystems Challenges

This paper applies the emerging concept of ‘relational values’ – values people hold toward their relationships with nature and with each other – and brings attention to the role of community science in enhancing relational ecosystem values. We feature Gouldsboro Shore, Gulf of Maine Research Institute’s (GMRI) coastal flood monitoring, and river herring monitoring and restoration efforts as focal examples. Gouldsboro Shore activates community volunteers and high school students to support the management and resilience of their clam fishery in Gouldsboro, ME. GMRI’s flood monitoring provides a platform for coastal residents to report, monitor, and map coastal flooding in participating municipalities. In multiple towns, biologists and community members have worked together to restore aquatic habitat and connectivity to support river herring populations while also deepening their connection to their local ecosystems. In each case, community science contributed to enhancing both people-nature and people-people relationships in the community to overcome coastal ecosystem challenges. Coastal decision-makers need to move beyond the antiquated Millennium Ecosystem Assessment framework to recognize a wider set of values that people hold towards coastal and marine natural environments. Community science programs have the potential to foster relational values and activate sustainability-aligned values into action to overcome ecosystem and other societal challenges

Learning and developing science capital through citizen science

Citizen science, the active participation of the public in scientific research projects, is a rapidly expanding field in open science and open innovation. It provides an integrated model of public knowledge production and engagement with science. As a growing worldwide phenomenon, it is invigorated by evolving new technologies that connect people easily and effectively with the scientific community. Catalysed by citizens’ wishes to be actively involved in scientific processes, as a result of recent societal trends, it also offers contributions to the rise in tertiary education. In addition, citizen science provides a valuable tool for citizens to play a more active role in sustainable development. This book identifies and explains the role of citizen science within innovation in science and society, and as a vibrant and productive science-policy interface. The scope of this volume is global, geared towards identifying solutions and lessons to be applied across science, practice and policy. The chapters consider the role of citizen science in the context of the wider agenda of open science and open innovation, and discuss progress towards responsible research and innovation, two of the most critical aspects of science today

Search for Global Dipole Enhancements in the HiRes-I Monocular Data above 10^{18.5} eV

Several proposed source models for Ultra-High Energy Cosmic Rays (UHECRs) consist of dipole distributions oriented towards major astrophysical landmarks such as the galactic center, M87, or Centaurus A. We use a comparison between real data and simulated data to show that the HiRes-I monocular data for energies above 10^{18.5} eV is, in fact, consistent with an isotropic source model. We then explore methods to quantify our sensitivity to dipole source models oriented towards the Galactic Center, M87, and Centaurus A.Comment: 17 pages, 31 figure

An upper limit on the electron-neutrino flux from the HiRes detector

Air-fluorescence detectors such as the High Resolution Fly's Eye (HiRes) detector are very sensitive to upward-going, Earth-skimming ultrahigh energy electron-neutrino-induced showers. This is due to the relatively large interaction cross sections of these high-energy neutrinos and to the Landau-Pomeranchuk-Migdal (LPM) effect. The LPM effect causes a significant decrease in the cross sections for bremsstrahlung and pair production, allowing charged-current electron-neutrino-induced showers occurring deep in the Earth's crust to be detectable as they exit the Earth into the atmosphere. A search for upward-going neutrino-induced showers in the HiRes-II monocular dataset has yielded a null result. From an LPM calculation of the energy spectrum of charged particles as a function of primary energy and depth for electron-induced showers in rock, we calculate the shape of the resulting profile of these showers in air. We describe a full detector Monte Carlo simulation to determine the detector response to upward-going electron-neutrino-induced cascades and present an upper limit on the flux of electron-neutrinos.Comment: 13 pages, 3 figures. submitted to Astrophysical Journa

Search for Point Sources of Ultra-High Energy Cosmic Rays Above 40 EeV Using a Maximum Likelihood Ratio Test

We present the results of a search for cosmic ray point sources at energies above 40 EeV in the combined data sets recorded by the AGASA and HiRes stereo experiments. The analysis is based on a maximum likelihood ratio test using the probability density function for each event rather than requiring an a priori choice of a fixed angular bin size. No statistically significant clustering of events consistent with a point source is found.Comment: 7 pages, 7 figures. Accepted for publication in The Astrophysical Journa

Search for Correlations between HiRes Stereo Events and Active Galactic Nuclei

We have searched for correlations between the pointing directions of ultrahigh energy cosmic rays observed by the High Resolution Fly's Eye experiment and Active Galactic Nuclei (AGN) visible from its northern hemisphere location. No correlations, other than random correlations, have been found. We report our results using search parameters prescribed by the Pierre Auger collaboration. Using these parameters, the Auger collaboration concludes that a positive correlation exists for sources visible to their southern hemisphere location. We also describe results using two methods for determining the chance probability of correlations: one in which a hypothesis is formed from scanning one half of the data and tested on the second half, and another which involves a scan over the entire data set. The most significant correlation found occurred with a chance probability of 24%.Comment: 13 pages, 1 table, 5 figure

Observation of the Ankle and Evidence for a High-Energy Break in the Cosmic Ray Spectrum

We have measured the cosmic ray spectrum at energies above $10^{17}$ eV using the two air fluorescence detectors of the High Resolution Fly's Eye experiment operating in monocular mode. We describe the detector, PMT and atmospheric calibrations, and the analysis techniques for the two detectors. We fit the spectrum to models describing galactic and extragalactic sources. Our measured spectrum gives an observation of a feature known as the ``ankle'' near $3\times 10^{18}$ eV, and strong evidence for a suppression near $6\times 10^{19}$ eV.Comment: 14 pages, 9 figures. To appear in Physics Letters B. Accepted versio