bluuebunny/crossref_metadata_2025_split huggingface dataset:
WORLDWIDE DISTRIBUTION AND ECOLOGY OF EURYCERCUS AND SAYCIA (CLADOCERA)1
Authors: Frey David G. 
Published: March 2010

The two species of Eurycercus are largely allopatric in the Northern Hemisphere, glacialis tending to be peripheral in distribution in the far north, occurring only as far south as 51‐52° N in the outer Aleutians, Labrador, and the northern Kuriles. There are vigorous disjunct populations of unknown history in oligotrophic heath and dune localities in Denmark and the Netherlands. The center of distribution is Greenland–Iceland. Eurycercus lamellatus is widely distributed over much of continental North America south to Mexico City and over much of Eurasia south to Algeria and southern Tibet. It also is known from farther north than glacialis. It is the only species occupying the large mountain masses of the Northern Hemisphere, where glacialis might be expected to occur. The center of distribution seems to be western Europe. Co‐occurrence of the two species in the same water bodies is known only for a few scattered lakes in Denmark, northern Sweden, Iceland, and Alaska.Eurycercus lamellatus also occurs as disjunct populations in Argentina and South Africa, but not at comparable latitudes in Australia and New Zealand. Here, Saycia cooki occurs, which might be considered an ecological equivalent of E. lamellatus except that it is confined to temporary water bodies.The finding of three males of Saycia from Australia—the first males ever recorded— stimulated a detailed study of the morphology of the species and a comparison with Eurycercus. Retention of the two genera in separate subfamilies seems justified. The male of Saycia is unique among chydorid Cladocera in having a plumose sexual seta on the antennule and in having the postabdominal claw spatulate at the tip. The sperm ducts open near the tip of the postabdomen, rather than at the base as in Eurycercus, the latter condition being unique among the chydorids.Saycia from New Zealand differs from the population in Australia chiefly in having more preanal teeth on the postabdomen and in being higher and having a shorter posterior margin relative to length of the animal. All these characters change with size. These regressions are presented and their significance discussed. The New Zealand population has been designated a new geographic subspecies, pending the eventual recovery of males.The number of postabdominal teeth in E. lamellatus increases with increasing size, making it likely that the species described as E. polyodontus merely represents individuals from the upper end of this regression. The number of teeth in E. glacialis is smaller than in lamellatus and does not increase with size of animal. The variability of tooth number within each species is so great that the number 100 proposed in the past cannot be used to separate the two species with any reliability. Similarly, the subspecies of Saycia from New Zealand has a larger tooth number, which shows a marked increase with size of animal, than that from Australia.
ENVIRONMENTAL CONTROL OF THE ABUNDANCE AND DISTRIBUTION OF THE CHYDORID CLADOCERA1
Authors: Goulden Clyde E. 
Published: March 2010

Littoral populations of chydorid Cladocera were studied in 1968 and 1969 at 3 collection areas in Lake Lacawac, Pennsylvania. The station on the sandy leeward margin of the lake had peak populations in spring, the one on the detritus rich windward shore peaked in late summer and fall, and the one at the interface between the sandy and detritus‐rich shores had peak populations in both spring and fall. At all areas the chydorids were least abundant in summer.There appeared to be ample food available in summer; chydorids were still able to reproduce after water temperatures had reached the summer maximum; and potential competitor species did not increase as chydorids decreased. Observations indicated that the summer population minimum was largely caused by predaceous tanypodine midges. The midges were most common, and the number of chydorids in their guts increased, just before major chydorid population declines. The midges were rare or absent in spring and fall when chydorids were most abundant.Eight species of tanypodines were found in the lake. Three were common from mid‐May to June; the others occurred in July. The first pulse of midges in June devastated the chydorid populations. The second pulse appeared only after the chydorids had recovered and began to develop large populations.
A 22,000‐YEAR POLLEN RECORD FROM THE PLATEAU OF ZAMBIA
Authors: Livingstone D. A. 
Published: March 2010

Pollen analysis of a core from Ishiba Ngandu in Zambia reveals only one significant change in the pollen assemblage laid down over a period of 22,000 yr. About 3,000 B.P. a number of taxa characteristic of moist to dry evergreen forest at low, moderate, or high altitudes declined from very low levels to even lower ones. This decline was probably both relative and absolute. At the same time a small group of taxa that grow in both swamp forest and savannah increased in a relative sense, although probably not in absolute deposition rate. Possibly this change represents the effects of agriculturalists on the vegetation.Neither montane forest nor moist forest of low and intermediate altitudes appears to have grown in this part of Zambia during the past 22,000 yr. The lack of dramatic changes in pollen cannot be attributed with any assurance to a stable climate, however, because it is unlikely that the vegetational changes to be expected if the rainfall changed by as much as 50% from the present mean level would be recognizable by pollen analysis.
DEEP‐SEA AMPHIPODA FROM THE WESTERN NORTH ATLANTIC OCEAN. THE FAMILY AMPELISCIDAE1,2
Authors: Mills Eric L. 
Published: March 2010

Eleven species of Ampeliscidae (Amphipoda) occur on a deep‐sea benthic transect between Massachusetts and Bermuda. Two species of Byblis and one of Byblisoides are newly described; Ampelisca uncinata Chevreux, Byblis gaimardi (Krøyer), B. serrata Smith, Haploops setosa Boeck, and H. similis Stephensen are redescribed or refigured; and new distributional or ecological information is given for Ampelisca aequicornis Bruzelius, A. agassizi (Judd), and A. declivitatis Mills. There is a rough taxonomic and ecological zonation of Ampeliscidac, with species of Ampelisca in shallow water, blind species of Byblis on the continental slope, species of Haploops on the slope extending into the abyss, and an endemic species of Byblisoides at fully abyssal depths which is adapted for feeding on large quantities of abyssal sediments by having strongly‐modified second antennae and massive antennal muscles. Bathyal species of Byblis and Haploops also appear to be sediment or suspension feeders but are less strongly modified.Zoogeographic affinities of the species are varied, especially on the continental slope. Shallow‐water species are Virginian and Carolinian, outer shelf species may range to north or south (but not both), and the Byblisoides is endemic to the North American Basin. The bathyal species are widespread around the North Atlantic or closely related to species from the northeast Atlantic.
CHEMICAL EXCHANGES BETWEEN SEDIMENTS AND WATER IN THE GREAT LAKES‐SPECULATIONS ON PROBABLE REGULATORY MECHANISMS1
Authors: Mortimer C. H. 
Published: March 2010

As long as the oxygen concentration at the sediment surface does not fall below 1 or 2 mg/liter, typical deep‐water sediments in the Great Lakes will probably be found to exert a measurable but quantitatively unimportant influence on the chemistry of the overlying waters. This conclusion is supported by the case of Windermere.The sequence of more conspicuous changes that take place when the oxygen does fall below 1 mg/liter at the interface is illustrated by the case of Esthwaite Water, representative of events in lakes where biological production or organic pollution is high, where the subthermocline volume is relatively small, or both. A progressive decline in oxygen concentration from 2 mg/liter to analytical zero at the interface was accompanied by a fall in electrode potential in the upper few millimeters of sediment, correlated with mobilization and transfer into the water first of manganese and later of iron. There is a concurrent transfer into the water of substantial quantities of phosphate, previously held in complex form, which may have important biological consequences. Other changes include liberation into the water of ammonia and silicate. Further reduction of the water‐sediment system permits microbial reduction of sulfate.A third example of sediment‐water exchange occurs during winter stratification under ice cover. In Torneträsk, in the course of 95 days of ice cover, a relatively thin layer of bottom water, initially at 1C, gained heat and bicarbonate from and lost oxygen to the sediments. The density increase, arising from the heat gain, set density currents in motion that drained this contact water into the deepest parts of topographically isolated subbasins.
PRODUCTION AND BIOENERGETIC ROLE OF THE MIDGE GLYPTOTENDIPES BARBIPES (STAEGER) IN A WASTE STABILIZATION LAGOON1
Authors: Kimerle Richard A. , Anderson N. H. 
Published: March 2010

The bioenergctic role of a population of Glyptotendipes barbipes in the process of waste stabilization in two sewage lagoons was studied. Weekly production rates of the multivoltine midge were computed. Annual production of G. barbipes was 808 kcal/m2 in a narrow band nearshore of the secondary lagoon containing 90% of the biomass.Biomass data from both lagoons in 1966 and 1967 were used to estimate production using a turnover ratio (TR) of 8.49 (ratio of production: mean biomass) from definitive data collected in 1967. Production in the secondary lagoon was 459 kcal/m2 in 1966 and 37 in 1967; in the primary lagoon it was 165 and 18 respectively. The factors causing these differences in production were probably the dissolved oxygen concentrations during the growing season, percent of the total lagoon bottom inhabitable by midge larvae, and the condition of the sludge substrate.The total energy removed by emergence and respiration of G. barbipes was compared with the energy in other pathways in the lagoon: import of sewage, primary production, community respiration, storage, and export. In 1966, G. barbipes removed about 6.6% of the net primary production in the secondary lagoon and 0.5% in 1967.
Analyses of Species Densities by the Multivariate General Linear Model
Authors: Buzas Martin A. 
Published: March 2010

A multivariate general linear model was constructed a priori to analyze observed species densities for three species of Foraminifera at 3 stations in the Choptank River, Maryland. The model contained 21 parameters for environmental variables, station differences, overall periodicity, and interaction of periodicity and station differences.Several more restricted models were postulated and compared with the general model. None of the more restricted models adequately explained the data. The high degree of complexity indicates that large complex models will be needed to explain observed species densities.
THE PHYSIOLOGICAL STATE WITH RESPECT TO NITROGEN OF PHYTOPLANKTON FROM LOW‐NUTRIENT SUBTROPICAL WATER AS MEASURED BY THE EFFECT OF AMMONIUM ION ON DARK CARBON DIOXIDE FIXATION1
Authors: Morris Ian , Yentsch Clarice M. , Yentsch Charles S. 
Published: March 2010

The ammonium ion enhancement method has been used to estimate the state of nitrogen nutrition in natural populations of marine organisms, with the advantage that the native population can be assessed at time zero. The ammonium ion does not stimulate dark CO2 fixation by natural populations of phytoplankton in the low nitrogen subtropical waters of the Florida Strait, indicating that the cells are not physiologically nitrogen deficient; however nitrogen may still be limiting population size.When enhancement was not noted at time zero, incubation of the water in a carboy resulted in depletion of the available nitrogen and a physiological state of nitrogen deficiency subsequently became measurable by this method. The eventual positive results from the test therefore confirm the negative results at time zero.
PRODUCTION OF CALCIUM CARBONATE ON THE MAINLAND SHELF OF SOUTHERN CALIFORNIA1
Authors: Smith S. V. 
Published: March 2010

Although calcareous organisms are abundant on hard‐bottom portions of the southern California mainland shelf, negligible amounts of CaCO3 are accumulating there.Data collected at three localities and 22 stations along the southern California coastline give subtidal rates of CaCO3 production by calcareous organisms, from turnover rates calculated from growth rate data, from mortality calculations based on size distribution and growth data, and from miscellaneous information, near 400 g CaCO3 m‒2 yr‒1. Although this temperate climate production rate is lower than rates of coral reef production, it is similar to tropical nonreef production rates and much higher than pelagic production rates of CaCO3.The CaCO3 produced is lost from the mainland shelf, probably by transportation to adjacent basins, and then is apparently in large part dissolved. About 4 × 1010 g CaCO3 yr‒1 are produced across 103 km2 of the shallow hard‐bottom shelf areas of southern California and subsequently removed from those areas.
PRODUCTION OF DISSOLVED ORGANIC MATTER FROM DEAD GREEN ALGAL CELLS. II. ANAEROBIC MICROBIAL DECOMPOSITION1
Authors: Otsuki Akira , Hanya Takahisa 
Published: March 2010

At the 60th day of anaerobic decomposition of dead cells of Scenedesmus sp. at 20C, the 30% of added algal cell carbon was transformed into dissolved organic carbon and 20% mineralized; 50% remained as particulate matter. On the other hand, 8% of the added algal cell nitrogen was transformed into dissolved organic nitrogen, 48% was mineralized, and 44% remained in particulate form.The dissolved organic compounds consisted mainly of lower fatty acids and yellowish acidic substances. Some proteinaceous material was found. Anaerobic decomposition patterns are compared with those under aerobic conditions and suggest the presence of relatively high concentrations of dissolved organic matter in anaerobic natural environments.
A COMPARISON OF CHEMICAL, ISOTOPIC, AND ENZYMATIC METHODS FOR MEASURING NITROGEN ASSIMILATION OF MARINE PHYTOPLANKTON1
Authors: McCarthy James J. , Eppley Richard W. 
Published: March 2010

Shipboard cultures of natural seawater enriched with nitrate, ammonium, or urea were used to compare different techniques for measuring nitrogen assimilation by phytoplankton and to measure the rates of uptake of these nutrients when more than one was present. Increases in particulate nitrogen, decreases of nitrogenous nutrients, and the uptake by phytoplankton (using the 15N‐isotope technique) balanced rather well and for the nitrate‐enriched culture were in good agreement with the estimate of nitrogen assimilation from nitrite reductase activity. Glutamic dehydrogenase activity was present with both NADH and NADPH in all three cultures; either singly or as a sum it agreed poorly with ammonium uptake estimated by the 15N‐isotope technique. The presence of ammonium almost totally suppressed the uptake of nitrate and urea over a wide range of concentrations. The suppression of nitrate uptake in the presence of urea was nearly the same as the suppression of urea uptake in the presence of nitrate.Comparisons between the isotopic and enzymatic techniques were also made in seawater samples. Nitrite reductase activity was usually much greater than the rate of nitrate uptake estimated by the 15N‐isotope technique. Comparisons with chlorophyll a and ATP analysis indicate that chlorophyll‐containing cells were primarily responsible for the nitrite reductase activity. The rate of pyridine nucleotide oxidation with both NADII and NADPII was more consistent with the ATP than with the chlorophyll a content of seawater samples, suggesting that this enzymatic activity was not restricted to the phytoplankton.
GROWTH INTERACTIONS BETWEEN CHLAMYDOMONAS GLOBOSA SNOW AND CHLOROCOCCUM ELLIPSOIDEUM DEASON AND BOLD: THE ROLE OF EXTRACELLULAR PRODUCTS
Authors: Kroes H. W. 
Published: March 2010

Extracellular substances were isolated from Chlorococcum culture filtrates and the four salt‐free groups of substances obtained tested separately on Chlamydomonas growth. The group of steam‐volatile substances had an overall promoting effect. The lipophilic group inhibited growth initially but had no lasting effect. The yellow, water‐soluble pigments (phenolic compounds) could act as chelating substances. The high molecular weight fraction (proteins and polysaccharides) promoted growth in the initial phase but had an inhibiting effect later on. These effects observed were mostly small but statistically significant.In algal interactions, inhibition phenomena are not likely to be caused by strong “antibiotic” substances. Factors such as pH may be more important than extracellular compounds as such.
FATTY‐ACID ECOLOGY OF A TIDAL MARSH1
Authors: Jeffries H. Perry 
Published: March 2010

A salt marsh has differing biochemical patterns: The grasses have a terrestrial pattern rich in 16–18 C fatty acids, the animals a marine pattern dominated by long‐chain polyunsaturates. The patterns vary, but they remain far more distinct than at corresponding positions in the structure of an offshore community.Each pattern is reflected in the diet of two species of marsh fishes. Their most probable diet is a mixture of 5 parts detritus to 1 part marine invertebrates. This ratio is also a boundary condition: It cannot go any higher and still account for the patterns occurring in the digestive tracts. Food is so abundant during spring that despite identical diets the two species could avoid competition.
COMPETITION BETWEEN AN ALGA AND AN AQUATIC BACTERIUM FOR PHOSPHATE1
Authors: Rhee G‐Yull 
Published: March 2010

Competition for phosphate was studied in Scenedesmus sp. and Pseudomonas sp. grown in pure and mixed cultures. Algal growth was severely limited in the presence of bacteria, but the growth of bacteria was hardly affected by algae. The first sign of competition in mixed cultures (cessation of exponential algal growth) was always observed some time after the external phosphate had been exhausted.The faster growth rate of bacteria accounted for the suppressed growth of the algae in the mixed cultures. The first sign of competition in algae appeared when the concentration of surplus phosphorus within the algal cell dropped to a critical value near zero. The surplus phosphorus appeared to consist of three or all four inorganic polyphosphate fractions.
INTERACTION OF SALINITY AND TEMPERATURE ON NET PROTEIN SYNTHESIS AND VIABILITY OF VIBRIO MARINUS1,2
Authors: Cooper Mary F. , Morita Richard Y. 
Published: March 2010

The relationship of temperature and salinity to protein synthesis was determined for cells of Vibrio marinus. The critical temperature of the lesion in protein synthesis increased with increasing salinity of the growth medium. Protein synthesis was significantly inhibited at 22C at a salinity of 25‰, but not at a salinity of 35‰ until the cells were incubated for 20 min at 24C. The thermal lesion did not involve precursor accumulation mechanisms rather than protein synthesis at salinities between 25 and 35%. At 40‰, the uptake of extracellular proline by whole cells was inhibited at 24C and preceded the inhibition of precursor into protein.Total RNA synthesis continued for 50 min at 22C in growth media at salinities between 15 and 35‰ but at 40‰ decreased after 20 min of cell incubation. At salinities between 15‰ and 30‰, total RNA synthesis continued at 15 and 22C, but cellular protein synthesis was inhibited by either temperature or salinity effects.Loss of cell viability at 22 and 25C at salinities of 25 and 35‰ showed that the onset of cell death occurs simultaneously with thermal inhibition of protein synthesis.
TURBULENT DIFFUSION OF OIL IN THE OCEAN1
Authors: Murray Stephen P. 
Published: March 2010

On‐site observations of oil slick geometries and current speeds during the Chevron spill of March 1970 in the Gulf of Mexico have allowed a comparative evaluation of the role of large‐scale turbulence (in the form of a horizontal eddy diffusivity) and surface tension effects in the spreading of oil from a continuously emitting well into a steady current. The initial outline of the slick (roughly the first 50% of slick length) follows the laws of expansion as predicted by Taylor’s turbulent diffusion theory. The gross size and overall shape (neglecting details of outline) of this type of slick are well represented by a solution to the Fickian diffusion equations which predict approximate slick geometry as a function of current speed, horizontal eddy diffusivity, the oil discharge rate, and an empirically determined constant (the boundary concentration).Under the conditions observed the effect of surface tension seems confined to within the first few hundred meters downslick and can probably be neglected for practical purposes under moderate oil discharge rates and current speeds as low as even 5 cm/sec.
THE RELATION OF PERIPHYTIC AND PLANKTONIC ALGAL GROWTH IN AN ESTUARY TO HYDROGRAPHIC FACTORS
Authors: Welch Eugene B. , Emery Richard M. , Matsuda Robert I. , Dawson William A. 
Published: March 2010

The seasonal periodicity of periphyton growth in the Duwamish estuary (Washington) is compared with that of phytoplankton and lends support to a previous conclusion that hydrographic conditions determine the timing of phytoplankton blooms despite high concentrations of dissolved nitrogen and phosphorus. Accumulation of periphyton on substrates increased in June and July to around 10 µg Chl a cm−2 week−1 and is related to incident light; conversely, phytoplankton blooms were delayed until August and September when hydrographic conditions were optimum for biomass accumulations of from 30–70 µg Chl a/liter.Maximum growth of periphytic and planktonic algae occurred at the same location in the estuary. This similarity in spatial distribution is not directly related to hydrographic conditions since the periphyton algae are sessile and more resistant to washout. The water in this section of the estuary presumably contained a more adequate supply of one or more limiting nutrients than water from adjacent locations.
Energy Harvesting with Single‐Ion‐Selective Nanopores: A Concentration‐Gradient‐Driven Nanofluidic Power Source
Authors: Guo Wei , Cao Liuxuan , Xia Junchao , Nie Fu‐Qiang , Ma Wen , Xue Jianming , Song Yanlin , Zhu Daoben , Wang Yugang , Jiang Lei 
Published: March 2010

AbstractInspired by biological systems that have the inherent skill to generate considerable bioelectricity from the salt content in fluids with highly selective ion channels and pumps on cell membranes, herein, a fully abiotic single‐pore nanofluidic energy‐harvesting system that efficiently converts Gibbs free energy in the form of a salinity gradient into electricity is demonstrated. The maximum power output with the individual nanopore approaches ∼26 pW. By exploiting parallelization, the estimated power density can be enhanced by one to three orders over previous ion‐exchange membranes. A theoretical description is proposed to explain the power generation with the salinity‐gradient‐driven nanofluidic system. Calculation results suggest that the electric‐power generation and its efficiency can be further optimized by enhancing the surface‐charge density (up to 100 mC m−2) and adopting the appropriate nanopore size (between 10 and 50 nm). This facile and cost‐efficient energy‐harvesting system has the potential to power biomedical tiny devices or construct future clean‐energy recovery plants.