Alignment of the atmospheric visibility monitoring telescope

Alignment of the first Atmospheric Visibility Monitoring Telescope has revealed errors in mount design, mount manufacture, software, and electronics. This article discusses error sources and solutions, and re-alignment results. Alignment requirements for operation are also presented. The telescope now operates with the desired accuracy and repeatability

Options for daytime monitoring of atmospheric visibility in optical communications

Techniques for daytime detection of atmospheric transmission and cloud cover to determine the capabilities of future deep-space optical communications links are considered. A modification of the planned nighttime photometry program will provide the best data while minimizing the need for further equipment. Greater degrees of modification will provide increased detection capabilities. Future testing of the equipment will better define the improvement offered by each level of modification. Daytime photometry is favored at certain wavelengths because of higher transmission and lower background noise, thus giving an increased signal-to-noise ratio. A literature search has provided a list of stars brighter than second magnitude at these wavelengths

Offshore Distances of Bowhead Whales (Balaena mysticetus) Observed during Fall in the Beaufort Sea, 1982–2000: An Alternative Interpretation

Nineteen years (1982– 2000) of sighting data from fall aerial surveys of bowhead whales (Balaena mysticetus) in the Alaskan Beaufort Sea were analyzed to determine how patterns in the distribution of migrating bowhead whales relate to annual sea-ice conditions. Transect sighting rate (transect sightings/km) indicated (ANOVA; F2, 980 = 143.84, p < 0.0001) that bowhead whales occurred farther offshore in years of heavy ice conditions (73.4 km, 95% CL: 67.2–79.6 km) than in years of moderate (49.3 km, 95% CL: 44.8–53.84 km), or light (31.2 km, 95% CL: 30.0–32.4 km) ice conditions. The most plausible explanation for the observed pattern in bowhead whale distribution is that in years of heavy ice conditions (annual pack ice; 1983, 1988, 1991), the developing landfast ice limits availability of shallow nearshore habitat, thus necessitating use of leads and ice openings in deeper water. We acknowledge that factors such as bathymetry, ocean currents, transport, and food availability may also interact to influence autumn distribution of bowhead whales. In heavy ice years, however, these factors likely exert less influence on bowhead whale distribution than in years with light to moderate ice conditions.Les données automnales prélevées à partir de relevés aériens pendant 19 années chez les baleines boréales (1982– 2000) (Balaena mysticetus) de la mer de Beaufort alaskienne ont été analysées dans le but de déterminer comment les tendances caractérisant la répartition des baleines boréales en migration se rapportent à l’état annuel des glaces et de la mer. Le taux de repérage transect (repérage transect/km) a indiqué (ANOVA; F2, 980 = 143.84, p < 0,0001) que les baleines boréales se trouvaient plus loin au large pendant les années où il y avait beaucoup de glace (73,4 km, 95 % CL: 67,2–79,6 km) que pendant les années où la glace était modérée (49,3 km, 95 % CL: 44,8–53.84 km) ou légère (31,2 km, 95 % CL: 30,0–32,4 km). L’explication la plus plausible à la source de la tendance qui a été observée en matière de répartition des baleines boréales, c’est que pendant les années où il y a beaucoup de glace (banquise; 1983, 1988, 1991), la glace de rive en formation limite la disponibilité d’habitats de faible profondeur à proximité du littoral, ce qui nécessite l’utilisation de chenaux et d’ouvertures dans la glace en eau plus profonde. On reconnaît que des facteurs comme la bathymétrie, les courants océaniques, le transport et la disponibilité de la nourriture peuvent également entrer en interaction au point d’exercer une influence sur la répartition automnale des baleines boréales. Cependant, pendant les années où il y a beaucoup de glace, ces facteurs sont susceptibles d’exercer moins d’influence sur la répartition des baleines boréales que pendant les années où la couverture de glace varie de légère à moyenne

The AP-3 Adaptor Complex Is Essential for Cargo-Selective Transport to the Yeast Vacuole

AbstractThree distinct adaptor protein (AP) complexes involved in protein trafficking have been identified. AP-1 and AP-2 mediate protein sorting at the trans-Golgi network and plasma membrane, respectively, whereas the function of AP-3 has not been defined. A screen for factors specifically involved in transport of alkaline phosphatase (ALP) from the Golgi to the vacuole/lysosome has identified Apl6p and Apl5p of the yeast AP-3 complex. Deletion of each of the four AP-3 subunits results in selective mislocalization of ALP and the vacuolar t-SNARE, Vam3p (but not CPS and CPY), while deletion of AP-1 and AP-2 subunits has no effect on vacuolar protein delivery. This study, therefore, provides evidence that the AP-3 complex functions in cargo-selective protein transport from the Golgi to the vacuole/lysosome

Connectivity of the bay scallop (Argopecten irradians) in Buzzards Bay, Massachusetts, U.S.A.

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Fisheries Oceanography 24 (2015): 364-382, doi:10.1111/fog.12114.The harvest of bay scallops (Argopecten irradians) from Buzzards Bay, Massachusetts, USA undergoes large interannual fluctuations, varying by more than an order of magnitude in successive years. To investigate the extent to which these fluctuations may be due to yearly variations in the transport of scallop larvae from spawning areas to suitable juvenile habitat (settlement zones), a high-resolution hydrodynamic model was used to drive an individual-based model of scallop larval transport. Model results revealed that scallop spawning in Buzzards Bay occurs during a time when nearshore bay currents were principally directed up-bay in response to a persistent southwesterly sea breeze. This nearshore flow results in substantial transport of larvae from lower-bay spawning areas to settlement zones further up-bay. Averaged over the entire bay, the spawning-to-settlement zone connectivity exhibits little interannual variation. However, connectivities between individual spawning and settlement zones vary by up to an order of magnitude. The model results identified spawning areas that have the greatest probability of transporting larvae to juvenile habitat. Because managers may aim to increase scallop populations either locally or broadly, the high-connectivity spawning areas were divided into: 1) high larval retention and relatively little larval transport to adjoining settlement areas, 2) both significant larval retention and transport to more distant settlement areas, and 3) little larval retention but significant transport to distant settlement areas.This project was supported by the Woods Hole Sea Grant through award NA10OAR4170083. All modeling computations were made on the University of Massachusetts at Dartmouth’s (UMD’s) GPGPU cluster, which was acquired with support from NSF award CNS-0959382 and AFOSR DURIP award FA9550-10-1-0354.2016-07-1

FVCOM validation experiments : comparisons with ROMS for three idealized barotropic test problems

Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): C07042, doi:10.1029/2007JC004557.The unstructured-grid Finite-Volume Coastal Ocean Model (FVCOM) is evaluated using three idealized benchmark test problems: the Rossby equatorial soliton, the hydraulic jump, and the three-dimensional barotropic wind-driven basin. These test cases examine the properties of numerical dispersion and damping, the performance of the nonlinear advection scheme for supercritical flow conditions, and the accuracy of the implicit vertical viscosity scheme in barotropic settings, respectively. It is demonstrated that FVCOM provides overall a second-order spatial accuracy for the vertically averaged equations (i.e., external mode), and with increasing grid resolution the model-computed solutions show a fast convergence toward the analytic solutions regardless of the particular triangulation method. Examples are provided to illustrate the ability of FVCOM to facilitate local grid refinement and speed up computation. Comparisons are also made between FVCOM and the structured-grid Regional Ocean Modeling System (ROMS) for these test cases. For the linear problem in a simple rectangular domain, i.e., the wind-driven basin case, the performance of the two models is quite similar. For the nonlinear case, such as the Rossby equatorial soliton, the second-order advection scheme used in FVCOM is almost as accurate as the fourth-order advection scheme implemented in ROMS if the horizontal resolution is relatively high. FVCOM has taken advantage of the new development in computational fluid dynamics in resolving flow problems containing discontinuities. One salient feature illustrated by the three-dimensional barotropic wind-driven basin case is that FVCOM and ROMS simulations show different responses to the refinement of grid size in the horizontal and in the vertical.For this work, H. Huang and G. Cowles were supported by the Massachusetts Marine Fisheries Institute (MFI) through NOAA grants DOC/NOAA/NA04NMF4720332 and DOC/ NOAA/NA05NMF472113; C. Chen was supported by NSF grants (OCE0234545, OCE0606928, OCE0712903, OCE0732084, and OCE0726851), NOAA grants (NA160P2323, NA06RG0029, and NA960P0113), MIT Sea grant (2006-RC-103), and Georgia Sea grant (NA26RG0373 and NA66RG0282); C. Winant was supported through NSF grant OCE-0726673; R. Beardsley was supported through NSF OCE—0227679 and the WHOI Smith Chair; K. Hedstrom was supported through NASA grant NAG13– 03021 and the Arctic Region Supercomputing Center; and D. Haidvogel was supported through grants ONR N00014- 03-1-0683 and NSF OCE 043557

A High-Speed, Wireless Network for Ship-to-Ship and Ship-to-Shore Data Exchange

Wireless networking equipment was installed on three research vessels and at three shore stations during the 1998 Thin Layers Experiment in East Sound, Washington. This wireless network provided high-speed data communication between scientists on separate vessels and permitted rapid transfer of data from vessels and from moored instruments to a common file server at one of the shore stations. This server was connected, via wireless link, to a local Internet service provider, thus permitting continuous Internet access from each vessel and each shore station. The wireless network used 900-MHz and 2.4-GHz spread spectrum systems and provided throughput comparable to T1 lines. Omnidirectional antennas were used between vessels and shore stations, providing communications at ranges up to 12 km. Such systems provide the capability for rapid data exchange during coordinated field operations and give investigators on separate vessels the opportunity to adapt sampling protocols to rapidly evolving conditions observed a few kilometers away

The Sec1/Munc18 protein Vps45 regulates cellular levels of its SNARE binding partners Tlg2 and Snc2 in Saccharomyces cerevisiae

Intracellular membrane trafficking pathways must be tightly regulated to ensure proper functioning of all eukaryotic cells. Central to membrane trafficking is the formation of specific SNARE (soluble N-ethylmeleimide-sensitive factor attachment protein receptor) complexes between proteins on opposing lipid bilayers. The Sec1/Munc18 (SM) family of proteins play an essential role in SNARE-mediated membrane fusion, and like the SNAREs are conserved through evolution from yeast to humans. The SM protein Vps45 is required for the formation of yeast endosomal SNARE complexes and is thus essential for traffic through the endosomal system. Here we report that, in addition to its role in regulating SNARE complex assembly, Vps45 regulates cellular levels of its SNARE binding partners: the syntaxin Tlg2 and the v-SNARE Snc2: Cells lacking Vps45 have reduced cellular levels of Tlg2 and Snc2; and elevation of Vps45 levels results in concomitant increases in the levels of both Tlg2 and Snc2. As well as regulating traffic through the endosomal system, the Snc v-SNAREs are also required for exocytosis. Unlike most vps mutants, cells lacking Vps45 display multiple growth phenotypes. Here we report that these can be reversed by selectively restoring Snc2 levels in vps45 mutant cells. Our data indicate that as well as functioning as part of the machinery that controls SNARE complex assembly, Vps45 also plays a key role in determining the levels of its cognate SNARE proteins; another key factor in regulation of membrane traffic

Acoustic doppler current profiler observations during the JGOFS AESOPS Antarctic polar front process studies I and II : R/V Revelle cruises from 30-Nov-97 to 3-Jan-98 and 13-Feb-98 to 19-Mar-98

We present velocity observations from a shipboard acoustic Doppler current profiler (ADCP) on RIV Revelle during cruises R9711 (30 November 1997 to 3 January 1998) and R9802 (13 February 1998 to 19 March 1998). The cruises were conducted as part of the Southern Ocean JGOFS (Joint Global Ocean Flux) Antarctic Polar Frontal Zone program. The ADCP was an RD Instruments hull-mounted 153-kHz narrowband unit. Data were collected nearly continuously during these Spring and Summer Process cruises, using an ensemble averaging interval of 2.5 min and a vertical bin length of 8 m. To reference the velocities to earth coordinates, we used GPS navigation in combination with the ship's gyrocompass and a GPS attitude system. An online version of this report is available at http://diana.coas.oregonstate.edu/sojgofs. In addition, the complete data sets and all processing details are available from the NODC Joint Archive for Shipboard ADCP: http://ilikai.soest.hawaii.edu/sadcp. This work was funded by National Science Foundation grant OPP-9530758