bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observations of Antarctic Polynya With Unmanned Aircraft Systems
Authors: Cassano John J. , Maslanik James A. , Zappa Christopher J. , Gordon Arnold L. , Cullather Richard I. , Knuth Shelley L. 
Published: August 2010

Working in the polar environment is always challenging, particularly during the winter, when environmental conditions are harshest. With hurricane force winds, frigid temperatures, and the potential to alter the global thermohaline circulation, the Terra Nova Bay region of Antarctica in the western Ross Sea is an environment where acquiring observations of local atmospheric and oceanic interactions is critical and also extremely challenging.An important feature of Terra Nova Bay is a recurring polynya—an area of nearly ice‐free water surrounded by sea ice and land. Strong katabatic winds (cold, negatively buoyant air that flows downslope under the influence of gravity) drain from the interior of the continent and blow over the open water of the polynya, resulting in large upward fluxes of heat and moisture. Sea ice production occurs as a result of the large transfer of heat from sea to air, with the newly formed sea ice blown offshore, effectively removing freshwater from the coastal ocean. The high‐salinity water created through this process becomes part of the global thermohaline circulation as Antarctic bottom water. Coastal polynyas, such as the one in Terra Nova Bay, are of interest to atmospheric scientists and oceanographers due to the intense air‐sea coupling and the impact of these fluxes on the state of the atmosphere and ocean.
Report on Climate Change E‐mails Exonerates Scientists
Authors: Showstack Randy 
Published: August 2010

A new report commissioned by the University of East Anglia (UEA) has largely exonerated climate scientists from the university's Climatic Research Unit (CRU) who wrote a number of controversial e‐mail messages that were made public without authorization in November 2009. Critics have argued that the e‐mails indicate that scientists had tampered with scientific data— including data related to land station temperatures and temperature reconstructions from tree ring analysis—subverted the peer review process, misused the Intergovernmental Panel on Climate Change (IPCC) process, and withheld data from critics.At a 7 July news conference to release the “Independent climate change e‐mails review,” report chair Muir Russell said, “Climate science is a matter of such global importance that the highest standards of honesty, rigor, and openness are needed in its conduct. On the specific allegations made against the behavior of CRU scientists, we find that their rigor and honesty as scientists are not in doubt.” He continued, “In addition, we do not find that their behavior has prejudiced the balance of advice given to policy makers. In particular, we did not find any evidence of behavior that might undermine the conclusions of the IPCC assessments.” Russell is chair of the Judicial Appointments Board for Scotland and formerly was principal and vice‐chancellor of the University of Glasgow, in Scotland.
NSF's Response to Gulf Oil Spill
Authors: Killeen Tim 
Published: August 2010

Under its statutory authority, the U.S. National Science Foundation (NSF) is using its Rapid Response Research (RAPID) funding mechanism to support research on the Deepwater Horizon oil spill. NSF issued a “dear colleague” letter on 27 May reminding the U.S. academic research community that RAPID awards are a special grant mechanism developed specifically by the foundation to respond to unanticipated events such as earthquakes, volcanic eruptions, hurricanes, and other natural and man‐made disasters where a timely response is essential to achieving research results.To date, NSF has received more than 90 unsolicited proposals for research and related activities from scientists and engineers at U.S. academic institutions wanting to launch or continue research in the Gulf of Mexico and along its shorelines related to the Deepwater Horizon oil spill. On the basis of reviews from NSF program officer teams, the foundation has funded 46 awards so far in fiscal year 2010, totaling $4.6 million for research and $2.5 million for ship costs.
Studying Active Lakes of Costa Rica: 7th Workshop of the IAVCEI Commission of Volcanic Lakes; Costa Rica, 10–19 March 2010
Authors: Rouwet Dmitri , Ohba Takeshi 
Published: August 2010

Volcanic lakes are surface manifestations of a volcano's deeper hydrothermal system. Insights into crater lake dynamics can be very useful in volcano monitoring programs (J. C. Varekamp and M. J. van Bergen (Eds.), Volcanic lakes and environmental impacts of volcanic fluids, J. Volcanol. Geotherm. Res., 178, 131–330, 2008). To bring together researchers with a variety of areas of expertise to study crater lake dynamics, the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) Commission of Volcanic Lakes (CVL) reunited in Costa Rica for its seventh workshop, almost 6 years after its last workshop, in Caviahue, Argentina.The main goal of CVL7 was to expand the multidisciplinary efforts of the scientific community. Quoting J. C. Varekamp, former CVL leader, volcanic lake science is “a special field with intertwined aspects of disciplines such as volcanology, limnology, geochemistry and biology/toxicology.” Considering that during the past decade, volcanic lake research was mainly focused on characterizing geochemical processes, an additional aim of the CVL7 workshop was to give renewed attention to the hazards posed by Nyos‐type lakes, named for a lake in Cameroon that stores carbon dioxide in its bottom waters.
Advances and Applications for Geodesy: 2010 UNAVCO Science Workshop; Boulder, Colorado, 8–11 March 2010
Authors: Calais Eric , Schwartz Susan , Arrowsmith Ramon 
Published: August 2010

Geodesy's reach has expanded rapidly in recent years as EarthScope and international data sets have grown and new disciplinary applications have emerged. To explore advances in geodesy and its applications in geoscience research and education, approximately 170 scientists (representing 11 countries: Colombia, Denmark, Ecuador, France, Japan, Lebanon, Mexico, New Zealand, Russia, Spain, and the United States), including 15 students, gathered at the 2010 UNAVCO Science Workshop in Colorado. UNAVCO is a nonprofit membership‐governed consortium that facilitates geoscience research and education using geodesy.Plenary sessions integrated discovery with broad impact and viewed geodesy through three lenses: (1) pixel‐by‐pixel geodetic imaging where various remote sensing methodologies are revealing fine‐scale changes in the near‐surface environment and the geologic processes responsible for them; (2) epoch‐by‐epoch deformation time series measured in seconds to millennia, which are uncovering ephemeral processes associated with the earthquake cycle and glacial and groundwater flow; and (3) emerging observational powers from advancing geodetic technologies. A fourth plenary session dealt with geodesy and water, a new strategic focus on the hydrosphere, cryosphere, and changing climate. Keynotes included a historical perspective by Bernard Minster (Scripps Institution of Oceanography) on space geodesy and its applications to geophysics, and a summary talk by Susan Eriksson (UNAVCO) on the successes of Research Experience in Solid Earth Science for Students (RESESS) and its 5‐year follow‐on with opportunities to mentor the next generation of geoscientists through cultivation of diversity.
Nutrient inflows into apple roots. II. Nitrate uptake rates measured on intact roots of mature trees under field conditions
Authors: BHAT K. K. S. 
Published: August 2010

Abstract The rates of uptake of nitrate‐N per unit length; surface area and volume of root were measured in solution depletion experiments conducted in a root laboratory, using intact roots of two 4.5‐year‐old apple trees (Discovery/M.9 and Worcester Pearmain/M.9) at two different depths in the soil profile.In Discovery/M.9, NO3− uptake rate per unit root was constant over the 20‐200 mmol m−3 range of solution concentration. In Worcester/M.9, the uptake rate per unit root over the 200‐150 mmol m−3 range (corresponding to a ‘lag’ phase) was lower than that over 150‐20 mmol m−3. The uptake rates after the lag phase at depths of 46 and 104 cm were ca. 1.3 and 5.0 times greater than those in Discovery/M.9 at the 46 and 110 cm depths, respectively. The concentration below which net uptake was zero was ca. 1 mmolm−3.In Discovery/M.9, the uptake rate per unit root at the 46cm depth was about 2.8 times that at 110 cm whereas in Worcester/M.9, the uptake rates at 46cm depth were about 1.8 and 1.4 times lower than those at 104cm over the solution concentration ranges 200‐150 and 150‐20 mmol m−3, respectively.Only small differences were observed in uptake rates per unit root between 1400‐1700 h, 2400‐0400 h, and 0700‐1100 h.For successive 5°C‐increments in root temperature between 5 and 25° C, the nitrate uptake rate per unit root increased by 130, 10, 30 and 5%, respectively. A major change in the activation energy for nitrate uptake was observed at a transition temperature located between 5°and 10°C.
China's emerging market for property rights: Theoretical and empirical perspectives1
Authors: Jefferson Gary H. , Rawski Thomas G. 
Published: August 2010

his paper contrasts state–directed and market–mediated reform of enterprise ownership rights in transition economies. We evaluate China's emerging market for enterprise ownership rights from the perspective of conditions underpinning the Coase Theorem: the assignment of property rights, the degree of competition, and the nature of transaction costs. China's recent experience suggests that policies designed to expand and support the scope of decentralized, market–based restructuring of ownership rights, even under conditions that deviate widely from the ideal assumptions underlying the Coase Theorem, may prove more beneficial than direct official intervention.JEL classification: G34, K11, L1 and P3.
Gender Segregation, Size of Workplace and the Public Sector
Authors: Burchell Brendan J. 
Published: August 2010

Gender segregation is considered to be a key structuring factor in the labour market, and is central to explanations of phenomena as diverse as the everyday experience of men’s and women’s employment to the underachievement of women and the limited impact of equal pay legislation.Studies of occupational segregation by gender tend to be polarized between qualitative and quantitative extremes. At the quantitative end, a primary focus of research has been to quantify segregation to a single index, permitting simple comparisons between countries and over time. However, detailed case studies of particular occupations have often hinted at ways in which breakdowns in occupational segregation have been replaced by other forms of gender segregation.This paper will present data showing that even within occupational categories there is still significant gender segregation and concentration by public/private sector and by size of workplace. For instance, female pharmacists are very over‐represented, and female gardeners very under‐represented, in the public sector. And the general tendency for women to work in smaller workplaces is severe for some occupations (e.g. office managers) and reversed in other occupations (e.g. production fitters). These analyses question the usefulness of single indices which take account only of segregation or concentration by occupation and therefore underestimate the gendering of job opportunities even within mixed occupations.
THE Si:C:N RATIO OF MARINE DIATOMS: INTERSPECIFIC VARIABILITY AND THE EFFECT OF SOME ENVIRONMENTAL VARIABLES1
Authors: Brzezinski Mark A. 
Published: August 2010

ABSTRACTThe variability of marine diatom Si:C and Si:N composition ratios was examined to assess their utility as ecological conversion factors. Twenty‐seven diatom species grown under an 18:6 h LD cycle and sampled at the end of the light period gave mean ratios, by atoms, of 0.13 ± 0.04 and 1.12 ± 0.33 for Si:C and Si:N ratios, respectively (95% C.I. reported). The mean ratios for 18 species grown under continuous illumination were 0.12 ± 0.03 for Si:C and 0.95 ± 0.23 for Si:N. The mean ratios of the clones grown under constant light were not statistically different from those calculated for the same species grown under an 18:6 h LD photoperiod. The overall mean Si:C and Si:N ratios for the 18:6 h LD and continuous light experiments taken together, weighted by the number of species in each experiment, are 0.13 and 1.05, respectively. The average ratios for the nine nanoplankton species (<20 μm) examined were 0.09 ± 0.03 for Si:C and 0.80 ± 0.35 for Si:N. The eighteen netplankton species (>20 μm) had higher mean ratios, Si:C = 0.15 ± 0.04 and Si:N = 1.20 ± 0.37.Time course sampling throughout a 24 h period revealed twofold variations in both ratios for individual species grown on a 14:10 h LD cycle. Changes in irradiance can also produce factor of two variations, both ratios being higher under low light. Comparisons of these data with those from the literature regarding the effects of temperature and nutrient limitation on diatom elemental composition suggest that use of these ratios to convert field estimates of biogenic silica into nitrogen or carbon units, or to estimate silica production from14C data, should yield results accurate to within a factor of three under most circumstances.
DEVELOPMENT OF THE FLAGELLAR APPARATUS AND FLAGELLAR ORIENTATION IN THE COLONIAL GREEN ALGAGONIUM PECTORALE(VOLVOCALES)1
Authors: Greuel Brian T. , Floyd Gary L. 
Published: August 2010

ABSTRACTVegetative cells ofGonium pectoralehave a fine structure similar to that ofChlamydomonas.In addition, three zones comprise an extracellular matrix; a fibrillar sheath and tripartite boundary surround individual cells, and a fragile capsule zone surrounds the entire colony. Cytokinesis is accomplished by a phycoplast and cleavage furrow.The flagellar apparatus of the immature vegetative cell of this colonial alga is similar to that ofChlamydomonas,but the basal bodies are slightly separated at their proximal ends. The four microtubular rootlets alternate between two and four members. During development, the basal bodies become further separated and nearly parallel. The distal fiber is stretched, but it remains attached to both basal bodies. At maturity, the basal bodies of peripheral cells of the colony have rotated in opposite directions on their longitudinal axes resulting in a displacement of the distal fiber to one side, an asymmetrical orientation of the rootlets and loss of 180° rotational symmetry. Central cells remain similar toChlamydomonasin that basal bodies do not rotate, rootlets are cruciate, the distal fiber remains medially inserted and 180° rotational symmetry is conserved. A “pin‐wheel” configuration of flagellar pairs and the orientation of parallel rootlets toward the colony perimeter probably accounts for the rotation of the colonies during forward swimming. In addition, these ultrastructural features support the traditional placement ofG. pectoraleas an intermediate between the unicellularChlamydomonasand the more complex colonial volvocalean genera.
SEA ICE MICROBIAL COMMUNITIES. V. THE VERTICAL ZONATION OF DIATOMS IN AN ANTARCTIC FAST ICE COMMUNITY1
Authors: Grossi Sarah McGrath , Sullivan C. W. 
Published: August 2010

ABSTRACTA distinct vertical zonation was observed among diatoms in a bottom congelation ice community at McMurdo Sound, Antarctica during the 1981 spring bloom. The bottom 20 cm of ice collected in December from four stations with variable snow cover was subdivided into 5 cm sections for analysis of algal distribution. Algal abundance was inversely related to the depth of snow cover, and generally decreased with increasing distance above the ice‐water interface. Most diatoms, including the dominant species Nitzschia stellata Manguin, Amphiprora kufferathii Manguin and Fragilaria islandica var. adeliae Manguin showed peak abundance in the bottom 10 cm of the ice, where the proportion of living to empty cells was also highest. Two species, however, an Auricula Castracane sp. and Navicula glaciei van Heurck, reached highest concentrations at depths 10–20 cm above the ice‐water interface. We considered two factors as contributing to the observed vertical zonation: (1) successive blooms at the ice‐water interface become spatially stratified within the ice by further accretion below; (2) a differential growth of species occurs along physicochemical gradients within the ice column. A comparison of early versus late season profiles suggests the latter mechanism may prevail once ice accretion has ceased.
PHOTOINHIBITION OF TEMPERATE LAKE PHYTOPLANKTON BY NEAR‐SURFACE IRRADIANCE: EVIDENCE FROM VERTICAL PROFILES AND FIELD EXPERIMENTS1
Authors: Elser James J. , Kimmel Bruce L. 
Published: August 2010

ABSTRACTTo evaluate the in situ occurrence of phytoplankton photoinhibition, the light‐mediated depression of chlorophyll in vivo fluorescence (IVF) and of the cellular fluorescence capacity (CFC) of phytoplankton was determined in three southeastern United States reservoirs. Vertical profiles of a fluorescence depression index (FDI) and of the CFC for reservoir phytoplankton showed that near‐surface photoinhibition of fluorescence properties occurred in association with high surface irradiance and weak vertical mixing of the water column. To characterize the time scales of photochemical and photosynthetic responses to and recovery from exposure to supraoptimal light intensity, phytoplankton IVF responses and 14C‐fixation rates were measured infield experiments. Phytoplankton chlorophyll IVF, CFC, and photosynthetic 14C fixation were rapidly (20–40 min) depressed when reservoir phytoplankton were exposed to surface irradiances (1700–2000 μE·m−2·s−1). Light‐mediated increases in the FDI declined rapidly (20–40 min) to pre‐exposure levels during a subsequent low‐light (75–200 μE·m−2·s−1) period, but CFC and 14C fixation recovered more slowly (>40 min). Exposure of reservoir phytoplankton to a light‐intensity gradient revealed both intensity and time thresholds for IVF and CFC depression. Phytoplankton photochemical responses to bright light operate on time scales that, in conjunction with vertical mixing, should limit the occurrence of photoinhibition to extreme irradiance environments. Our results support the hypothesis that the photoinhibition of phytoplankton productivity occurs less commonly than is indicated by fixed‐depth incubation measurements.
PHOTOSYNTHETIC ELECTRON TRANSPORT IN CELL‐FREE EXTRACTS OF DIVERSE PHYTOPLANKTON1,2
Authors: Samuelsson Göran , Prezélin Barbara B. 
Published: August 2010

ABSTRACTA simple and rapid procedure for preparing thylakoid membranes that are active in photosynthetic electron transport from diverse phytoplankton species is described. The method requires disruption of algal cells with glass beads, exposure to mild hypotonic stress, and subsequent enrichment of the thylakoid membranes by differential centrifugation. Isolated thylakoid membranes were assayed for photosynthetic electron transport activity by measuring rates of oxygen consumption and oxygen production, using a variety of electron donors and acceptors. In the dinoflagellate Gonyaulax polyedra Stein, a relatively broad pH optimum between 7.0 and 8.0 was determined for the whole chain electron transport from water to methyl viologen. The preparation maintained maximum activity for 45 min following the preparation. The assay for photosystem I activity in G. polyedra, determined as electron flow from ascorbate/2,6‐dichlorophenolindophenol to methyl viologen, had a somewhat narrower pH optimum around 8.0. Rates of whole chain photosynthetic electron transport on a per cell and on a per chlorophyll a basis were shown to decrease dramatically with cell age in batch cultures of G. polyedra. Using the procedures optimized for G. polyedra, reproducible rates of electron transport on a per cell chlorophyll a basis were also measured in cultures of the dinoflagellate Glenodinium sp., the diatom Nitzschia closterium (Ehrenberg 1839) Wm. Smith 1853 and the chrysophyte Monochrysis lutheri Droop {= Pavlova lutheri (Droop) Green}.Other electron transport assays applied to G. polyedra, and that resulted in comparable rates to those found in other algal groups, include the photosystem II assay from water to diaminodurene/ferricyanide and the photosystem I assay from durohydroquinone to methyl viologen.
ULTRASTRUCTURE OF MITOSIS AND CYTOKINESIS INKLEBSORMIDIUM MUCOSUMNOV. COMB., FORMERLYULOTHRIX VERRUCOSA(CHLOROPHYTA)1
Authors: Lokhorst Gijsbert M. , Star Wim 
Published: August 2010

ABSTRACTA transmission electron microscopy study of dividing cells ofUlothrix verrucosaLokhorst has provided clear evidence that this species differs in many respects from otherUlothrixKützing species. These differences include the presence of a microtubular sheath around the prophase nucleus, the complete disintegration of the nuclear envelope coinciding with the proliferation of extranuclear microtubules into the prometaphase nucleus and the intrusion of vacuoles into the interzonal spindle region in between the widely separated telophase nuclei. This necessitates the transfer ofUlothrix verrucosato the charophycean genusKlebsormidiumSilva, Mattox and Blackwell. The new combinationKlebsormidium mucosumis proposed. On account of its mitotic pattern, this species can be placed in the (charophycean) evolutionary line towards the higher plants. However, because of its cytokinesis (annular centripetal ingrowth of the plasmalemma) this species probably should be considered as a blind offshoot of this line. It is emphasized that furrowing green algae with a persistent interzonal spindle at telophase (including the presently studied alga) often show an ill‐defined cytokinetic microtubular system.
THE OPTIMUM PH OF FOUR STRAINS OF ACIDOPHILIC SNOW ALGAE IN THE GENUS CHLOROMONAS (CHLOROPHYTA) AND POSSIBLE EFFECTS OF ACID PRECIPITATION1
Authors: Hoham Ronald W. , Mohn William W. 
Published: August 2010

ABSTRACTFour axenic strains of snow algae were examined for optimum pH under laboratory conditions using M‐1 growth medium. Growth was measured using cell counts, cell measurements and absorbance readings at 440 nm. Strains C204 and C479A of Chloromonas sp. from the Adirondack Mountains, New York, grew optimally at pH 4.0 to 5.0. Strains C381F and C381G, Chloromonas polyptera (Fritsch) Hoh., Mull. & Roem. from the White Mountains, Arizona, grew optimally at pH 4.5 to 5.0. Growth was significantly higher at pH 4.0 in the northeastern species (Chloromonas sp.), but no significant difference was observed in final growth at pH 4.5, 5.0 and 5.5 between species. It is postulated that the more acidic precipitation in the northeastern United States may be selecting for strains of snow algae with greater tolerance to acidity than in strains from the southwestern United States or that the different pH optima reported are simply species differences. New York strain C204 was also grown in heavily buffered AM medium where it had an optimum pH of 5.0, but cells became irregularly shaped and tended to clump at pH 6.0 to 7.0. Growth of C204 in AM medium was significantly lower than in M‐1 medium for snow algae. These findings justify the use of M‐1 medium for this type of experimentation.