Ecology of a reef forming serpulid, Hydroides norvegica : final report

Experimental results reported herein were obtained on colonies of serpulid worms collected from a filter box (Fig. 1) through which water was pumped at a rate of about 1,000 gallons per day. The filter box was located within and the water was drawn from the cooling water intake system of the Central Power and Light Company plant located between the Port of Corpus Christi and Nueces Bay, Texas. Although at least three species of serpulids were identified from this locality during the spring of 1969, all specimens collected for experimentation included only Hydroides norvegica. Salinity of the water in the Port of Corpus Christi ranged from 29 to 35 ppt through the sampling period.Marine Scienc

Upperslope Oilseep Study: I. Geological and Geophysical Results. II. Geochemical and Stable Isotope Results

This is a report on the geology of the first well-documented oil seep actually sampled in the northern Gulf of Mexico. The area studied lies about 220 km south of Morgan City, Louisiana on the upper continental slope.Institute for Geophysic

Use of the Goldberg Refractometer as a salinometer for biological and geological field work

The Goldberg Refractometer (American Optical Co., model 10402) has been tested as a potential field salinometer. The instrument has a range of 0 to 220‰ and an accuracy of about one ppt. Although it is inaccurate relative to titration and conductimetric salinometers, the Refractometer has the advantages of temperature compensation, small size, small sample requirements, large range, and low cost

Environmental Considerations in Naval Operations

With its historic mission clearly defined as supporting the operational fleet, the Oceanographic Office of the U.S. Navy in recent years has expanded its efforts to also meet the growing challenge of working within a national program of studying the marine environment

Beach impact study, Padre Island National Seashore

Prepared for Office of Natural Science, Southwest Region, National Park Service, under contract CX70005044830 April 1976Vegetative differences between heavily and very lightly trafficked beaches show that more beach traffic correlates with quantitative decreases in variety and density of plants and with declines of grasses relative to forbs. The vegetated portions of all beaches continue to grow in volume. However, this is at the expense of the more seaward (more trafficked) parts of the beaches and has lead to overall loss of total beach volume except where vehicular traffic is prohibited. The very lightly trafficked beach is the only study site wherein the entire beach to mean sea level has grown. The effect of these trends on resistance to storm surge erosion remains to be tested.Marine Scienc

Beach impact study, Padre Island National Seashore

The purpose of this study is to determine if the rapidly increasing vehicular and pedestrian traffic on the beaches of the Padre Island National Seashore is adversely affecting the long term stability of the vegetated foredune system. At each of the four study sites a pair of concrete and steel monuments was erected along a range line perpendicular to the local shoreline. This enables the survey crew to measure exactly the same profile line during each survey in order to accurately measure small amounts of erosion or accretion. During each survey, elevations are determined every 10 feet along the range line. A level loop including the stations at NOTRAF, PEDTRAF, and VEHTRAF has been closed so that those three stations are all relative to the same datum. The datum is approximately mean sea level as determined from local water level and a tide gage located at the Corpus Christi Water Exchange Pass. The datum for SHELL is also approximately mean sea level and was determined in the same fashion, but was not tied in to the other three stations by a level loop because of the distance involved. The study areas were profiled monthly from April 1974 through July 1974 and bimonthly thereafter. During the fall and winter study periods, qualitative vegetative data was collected at each of the four study sites during each survey. The species present in each zone of each study area were noted as well as their effectiveness in sand stabilization and trapping. During November 1974 detailed maps of the vegetation at NOTRAF and VEHTRAF were compiled in order to better understand the function of each species in sand stabilization. A similar map was compiled in SHELL during December. These maps are representative of the individual localities and broadly representative of each traffic usage level for the fall and early winter months.Marine Scienc

Distal Insertional Footprint of the Brachialis Muscle: 3D Morphometric Study

Objective. The purpose of this study is to describe the three-dimensional morphometry of the brachialis muscle at its distal attachment to the ulna. Methods. Fifty cadaveric elbows were dissected and the brachialis distal insertion was isolated on the ulna bone and probed with a three-dimensional digitizer, to create a three-dimensional model of the footprint. Measurements and analysis of each footprint shape were recorded and compared based on gender and size. Results. There was significant gender difference in the surface length (P = 0.002) and projected length (P = 0.001) of the brachialis footprint. The shapes of the footprint also differed among the specimens. Conclusion. The shape of the brachialis muscle insertion differed among all the specimens without significant variation in gender or sides. There was also a significant difference in muscle length between males and females with little difference in the width and surface area. Significance. The information obtained from this study is important for kinematic understanding and surgical procedures around the elbow joint as well as the understanding of the natural age related anatomy of the brachialis footprint morphology

Single nucleotide polymorphisms of the ovine ADRB3 gene in crossbred Australian sheep supplemented with spirulina (Arthrospira platensis) cyanobacterial microalgae

The adrenergic-receptor beta3 (ADRB3) gene is an obesity gene that is involved in the regulation of energy balance and a variety of physiological functions by increasing lipolysis and thermogenesis. Spirulina (Arthrospira platensis) is a blue-green cyanobacterial alga containing 60-70% protein with an extensive history of human consumption, and more recently, inclusion in animal feeds. We had earlier demonstrated that low level oral supplementation by drenching prime lambs with 100 mL/head/day of 1g of Spirulina powder dissolved in 10 mL of water (10%wt:vol) increased live weight and body conformation measurements in Black Suffolk (BS) x Merino crossbred sheep. The hypothesis that genetics-nutrition interactions between sheep breeds with fewer mutations at the ADRB3 locus and an optimal Spirulina supplementation level will increase lean meat production was tested in the current study. Forty-eight crossbred Australian prime lambs sired by four rams of diverse breeds under the same pasture-based management conditions were subjected to a nine-week feeding trial with Spirulina, followed by genomic DNA extraction and single nucleotide polymorphism (SNP) analysis. Eleven SNPs in both the coding and noncoding regions of the ovine ADRB3 gene were detected. Nine of the SNPs were in exon I and two in the intron. Variations in SNP frequencies were highly significant (P <0.0001) between all sheep breeds. The maximum and minimum number of SNPs were found in purebred Merinos (4.83) and Black Suffolk x Merino (BS) crossbreds (1.67). In total, one indel and six transverse mutations were detected that resulted in six amino acid substitutions. BS crossbreds had the lowest frequency of mutation and amino acid substitutions in their population in agreement with our hypothesis. In conclusion, BS sheep genetics matched with low level (100 mL/head/day) of Spirulina supplementation can lead to higher meat production with less fat content in a typical pasture-based sheep production system

Actionable Neural Representations: Grid Cells from Minimal Constraints

To afford flexible behaviour, the brain must build internal representations that mirror the structure of variables in the external world. For example, 2D space obeys rules: the same set of actions combine in the same way everywhere (step north, then south, and you won't have moved, wherever you start). We suggest the brain must represent this consistent meaning of actions across space, as it allows you to find new short-cuts and navigate in unfamiliar settings. We term this representation an `actionable representation'. We formulate actionable representations using group and representation theory, and show that, when combined with biological and functional constraints - non-negative firing, bounded neural activity, and precise coding - multiple modules of hexagonal grid cells are the optimal representation of 2D space. We support this claim with intuition, analytic justification, and simulations. Our analytic results normatively explain a set of surprising grid cell phenomena, and make testable predictions for future experiments. Lastly, we highlight the generality of our approach beyond just understanding 2D space. Our work characterises a new principle for understanding and designing flexible internal representations: they should be actionable, allowing animals and machines to predict the consequences of their actions, rather than just encode

Biological and physical ocean indicators predict the success of an invasive crab, Carcinus maenas, in the northern California Current

An introduced population of European green crabs Carcinus maenas was established in San Francisco Bay (California, USA) prior to 1989. Subsequently, their larvae were likely carried northward into the embayments of Oregon, Washington (USA), and British Columbia (Canada) by the unusually strong Davidson Current during the winter of the El Niño of 1997-1998. Since this colonizing event, green crabs in Oregon and Washington have persisted at low densities. In this study, we show that after the arrival of the strong founding year-class of 1998, significant recruitment to the Oregon and Washington populations has occurred, but only in 2003, 2005, 2006 and 2010. Warm winter water temperatures, high positive values of the Pacific Decadal Oscillation (PDO) and Multivariate ENSO (El Niño Southern Oscillation) indices in March, weak southward shelf currents in March and April, a late biological spring transition, and high abundance of subtropical copepods are all strongly correlated with strong year-classes. We hypothesize that northward transport of larvae from California by coastal currents during warm winters is the mechanism by which the larvae are delivered to the Pacific Northwest. Among the best indicators of northward flow (and green crab recruitment) were the date of ‘biological spring transition’, the sign of the PDO, and the biomass of southern copepod species, which indicate (1) stronger northward flow of coastal waters during winters, (2) relatively warm winters (sea surface temperature >10°C), which enable larvae to complete their development in the near-shore, and (3) coastal circulation patterns that may keep larvae close to shore, where they can be carried by tidal currents into estuaries to settle.Keywords: El Niño, California current system, Plankton community structure, Year-class strength, Alongshore currents, Recruitment, Pacific Decadal Oscillation, European green crabKeywords: El Niño, California current system, Plankton community structure, Year-class strength, Alongshore currents, Recruitment, Pacific Decadal Oscillation, European green cra