bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of the Amazon River plume on distributions of free‐living and symbiotic cyanobacteria in the western tropical north Atlantic Ocean
Authors: Foster R. A. , Subramaniam A. , Mahaffey C. , Carpenter E. J. , Capone D. G. , Zehr J. P.
Published: July 2010

The vertical and horizontal distributions of seven diazotrophic populations in the western tropical north Atlantic (WTNA) Ocean were examined using a nifH DNA quantitative polymerase chain reaction (QPCR) approach. The nifH phylotype abundances were highest near the surface and decreased with depth, with the exception of the cyanobacterial symbiont Calothrix, which was not detected at any station. Richelia associated with the diatoms Rhizosolenia clevei and Hemiaulus hauckii were distributed within the freshwater lens of the Amazon plume. Abundances of H. hauckii‐Richelia nifH genes dominated all depths in 6 of 10 vertical profiles and 10 of 20 surface samples. In addition, estimates of Richelia associated with H. hauckii increased northwest (8‐ 12°N, 56‐54°W) from the river mouth, where significantly ( p < 0.001) higher abundances (>105 copies L−1) were found in mesohaline waters (31‐34.9). nifH copy abundance for surface populations of the H. hauckii‐Richelia symbioses were positively correlated (r2 = 0.59) with salinity. Three unicellular cyanobacterial groups and Trichodesmium had similar horizontal distributions, where the highest nifH copy estimates were at stations with salinity ≥35 and northeast (6‐10°N 50°W) of the freshwater lens. The abundance of Trichodesmium spp. and unicellular Group B nifH gene copies co‐varied (r2 = 0.60). The QPCR study showed the dominance of H. hauckii‐Richelia symbioses in the Amazon plume waters, implying that these associations had an ecological advantage over the other diazotrophs. Outside of the plume nutrients were below detection, abundances of freeliving unicellular cyanobacterial phylotypes, including a novel group designated Group C, were abundant (>105 copies L−1) and comparable to the abundances of Trichodesmium spp. Thus, there appeared to be a cascade of diazotrophic communities along gradients of salinity and nutrients in the WTNA.
Diagenetic and sedimentological controls on the composition of organic matter preserved in California Borderland Basin sediments
Authors: Mollenhauer Gesine , Eglinton Timothy I.
Published: July 2010

Compound‐specific radiocarbon (14C) contents, stable carbon isotopes, and abundances of phytoplankton and vascular plant derived lipid biomarkers (alkenones and fatty acids) were obtained from Santa Barbara Basin and Santa Monica Basin sediments, along with radiocarbon contents of planktic foraminifera and total organic carbon. We investigated core‐top and prebomb sediment intervals at sites from the flanks and depocenters of the basins deposited under contrasting bottom water oxygen concentrations. Bulk organic matter generally has the lowest radiocarbon levels of all sediment constituents measured, whereas planktic foraminifera tend to be the most radiocarbon enriched. Alkenones are systematically depleted in radiocarbon with respect to foraminifera. Short‐chain (C14, C16, C18) fatty acids decrease rapidly in absolute abundance and relative to longer‐chain (>C24) homologues from core‐top to prebomb samples. The loss of short‐chain fatty acids with depth is associated with 13C depletion of short‐chain fatty acids, indicating preferential preservation of terrestrially derived fatty acids. Short‐chain fatty acids tend to be more 14C‐enriched relative to alkenones in core‐top sediments, whereas longerchain homologues are generally the most radiocarbon depleted of the lipids studied here. Less refractory compounds (e.g., short‐chain fatty acids) are thus enriched in radiocarbon with respect to more recalcitrant biomarkers (alkenones, long‐chain fatty acids). The lower 14C content of more refractory compounds reflects a larger proportion of laterally supplied, preaged material. Greater preservation of labile organic compounds observed at the depocenters than in flank sediments results in the presence of “younger” biomarkers, underlining the important influence of selective degradation of labile compounds on their radiocarbon ages.
Biostabilization of cohesive sediment beds in a freshwater wave‐dominated environment
Authors: Droppo Ian G. , Ross Nathalie , Skafel Michael , Liss Steven N.
Published: July 2010

An assessment of bed sediment stability was carried out over biostabilized and nonbiostabilized cohesive sediment within a laboratory wave flume. Biofilms of 5, 9, and 15 d were grown over kaolinite, and changes in bed shear stress were applied through increasing wave height. Results show that the stability of the bed was highly related to the structural integrity of the overlying and integrated biofilm. Biofilms with substantial algal growth and lifting, due to decay and gas production, were weaker than those in contact with the bed. Generally, biostabilized beds of the same age failed at similar shear stresses (although the mechanism of failure varied), and the 9‐d biofilms exhibited the greatest strength. Changes in the microbial diversity and dominant species with time, as measured with phospholipids fatty acid analysis (PLFA) and denaturing gradient gel electrophoresis (DGGE), are believed to have influenced the observed variations in bed strength. Young biofilms were dominated by bacterial species, whereas older biofilms were dominated more by algae (particularly cyanobacteria). Fungal species also played a large role in the biofilm development and structure. Laser confocal microscopy and environmental scanning electron microscopy were used to show structural differences between biofilms and changes with wave energy. Biofilm development and bio‐armoring of underlying cohesive sediments are successional processes, with new layers of biofilm integrating into the sediment beneath older decaying biofilm layers. As such, there is a continuous temporal oscillation in bed sediment stability depending on the stage of biofilm development and decay.
Accounting for grazing dynamics in nitrogen‐phytoplankton‐zooplankton (NPZ) models
Authors: Mitra Aditee , Flynn Kevin J. , Fasham Michael J. R.
Published: July 2010

Nitrogen‐phytoplankton‐zooplankton (NPZ)‐type models are widely used to explore the dynamics of marine planktonic ecosystems. Within these models, grazing by zooplankton on phytoplankton that are subjected to varying degrees of nitrogen limitation is described using N‐based grazing kinetics together with fixed N assimilation efficiency. There is no empirical evidence for zooplankton displaying such behavior; on the contrary, there is evidence for a decline in zooplankton growth rates on consumption of N‐impoverished prey, with decreased assimilation efficiencies coupled with decreased ingestion rates of nutrient‐limited (i.e., poor quality, low N: C) prey. Unwittingly, then, traditional NPZ models make unjustified assumptions concerning changes in predator‐prey interactions on consumption of low‐quality prey. We explore the effects of this flawed description, also asking why NPZ models can still give reasonable descriptions of field data. Our conclusion is that one flaw may be countered by another, namely, by an inadequate description of nongrazing phytoplankton losses. In nature, these nongrazing losses are enhanced within nutrient‐depleted phytoplankton populations. In models, a decline in grazing losses on nutrient‐deprived phytoplankton is, de facto, compensated for by enhanced nongrazing losses. While the fit of the revised model to the data is not dissimilar to that of the original model (with its inappropriate descriptions of grazing and nongrazing phytoplankton mortality), the fate of primary production is very different. With the biologically more acceptable description, more material flows through the detrital compartment, with important implications for trophic dynamics. Care must be taken not to oversimplify descriptions of biology in models, as these may directly or indirectly mask the simulation of other important ecological processes.
Bleaching, energetics, and coral mortality risk: Effects of temperature, light, and sediment regime
Authors: Anthony Kenneth R. N. , Connolly Sean R. , Hoegh-Guldberg Ove
Published: July 2010

The most severe outcome of coral bleaching is colony mortality. However, the risk of mortality is one of the least understood consequences for reef corals under climate‐change scenarios. Specifically, links among combinations of temperature anomalies, varying solar irradiance, reduced water quality, and mortality risks are unclear. Here, we analyze the effects of high temperature, irradiance, and sediment loading on coral survivorship in a controlled tank experiment using Acropora intermedia from the inner Great Barrier Reef lagoon. Survival analyses based on the fate of 1600 subcolonies revealed that temperature and sediment exerted strong effects on coral mortality risk. As expected, high temperature increased mortality risk at all light and sediment levels. However, high sediment reduced mortality under high temperature and/or high light, potentially by alleviating light pressure and by providing an alternative food source for bleached corals. A survivorship model using coral energy status (lipid stores) as a predictor variable provided an excellent fit to the data, suggesting that much of the variation in survivorship among treatments and over time can be explained by colony energetics. Our study provides a new framework for predicting coral mortality risk under complex bleaching scenarios in which multiple environmental variables are involved.
Does low temperature constrain the growth rates of heterotrophic protists? Evidence and implications for algal blooms in cold waters
Authors: Rose Julie M. , Caron David A.
Published: July 2010

Literature review and synthesis of growth rates of aquatic protists focused on the role of temperature in the formation of massive annual algal blooms in high‐latitude ecosystems. Maximal growth rates of herbivorous protists equaled or exceeded maximal growth rates of phototrophic protists at temperatures above 15°C. Maximal growth rates of herbivorous protists declined more rapidly with decreasing temperature than did those of phototrophic protists, and at the very low temperatures common to high‐latitude ecosystems, the maximal growth rates of herbivorous protists were less than half the maximal growth rates of phototrophic protists. Growth rates of herbivorous protists were consistently lower than those of bacterivorous protists and were unrelated to differences in cell volume between the two groups. Linear equations describing the relationship of the natural log of maximal growth rates of bacterivorous and herbivorous protists to temperature were generated and compared to published information for maximal growth rates of phototrophic protists and copepods. The three heterotrophic groups had similar slopes (0.12 for bacterivorous protists, 0.10 for herbivorous protists, and 0.13 for copepods) that were approximately double that of phototrophic protists (0.06). The massive annual algal blooms observed in high latitudes are due in part to a fundamental difference in the relationship between growth and temperature for phototrophic protists and their grazers.
Large‐scale coherence in the response of lake surface‐water temperatures to synoptic‐scale climate forcing during summer
Authors: Livingstone David M. , Padisák Judit
Published: July 2010

Daily mean lake surface‐water temperatures (LSWTs) measured in Swiss Alpine lakes in summer and early autumn 2000 were compared with LSWTs measured simultaneously in Lake Balaton, Hungary, 750 km to the east. The Swiss lakes are small (0.0043–0.46 km2), predominantly oligotrophic, and are located in a mountainous environment, some at altitudes >2,000 m above sea level, whereas Lake Balaton is a large (593 km2), shallow, mesotrophic lake situated in the much lower‐lying Carpathian Basin. Despite the large distance separating the two regions and the extreme differences in character between the lakes, the LSWTs in Switzerland and Hungary exhibited a coherent response to synoptic‐scale meteorological forcing, expressed in terms of exponentially smoothed air temperature, which can be viewed as a causal forcing variable in its own right and as a proxy for other forcing variables with which it is correlated. The coherent response of LSWT in very dissimilar lakes in two different geographical regions of Europe demonstrates that largescale climatic forcing on synoptic timescales is much more important for lakes than previously thought. This appears to be particularly true for low‐altitude lakes, whereas lakes at higher altitudes exhibit more heterogeneity in their response.
Physical, chemical, and microbial regimes in an anoxic fjord (Nitinat Lake)
Authors: Pawlowicz Rich , Baldwin Susan A. , Muttray Annette , Schmidtova Jana , Laval Bernard , Lamont Grant
Published: July 2010

New observations of physical, biological, and chemical parameters were obtained between July 2003 and February 2005 in Nitinat Lake, British Columbia, a permanently anoxic seawater fjord. These observations include continuous profiles of nitrate and bisulfide using a new instrument for in situ ultraviolet spectrophotometry. Anoxic seawaters in this 200‐m—deep basin can be found as shallow as 7 m. However, Nitinat Lake is surprisingly dynamic, with a deep‐water renewal time of only about 5 yr and significant spatial and temporal variability. Exchange with the ocean is limited by the size of the linking channel, and during low tides the outflow is subject to an hydraulic control. This nonlinearity causes a relatively large fortnightly cycle in water level and explains flooding events associated with heavy rainstorms. In addition, the restricted flow makes deep‐water renewal gradual so that anoxic conditions are preserved. Intermediate waters (5‐40 m in depth) are renewed alternately by oxygenation from surface mixing in winter and by upwelling of anoxic water and horizontal inflow of subducted ocean water in summer. The horizontal inflow results in a subsurface region of suboxic water in mid‐fjord during summer. No suboxic regime is evident at either the river end of Nitinat Lake (where oxygen and sulfide‐rich regions adjoin in a nitrate‐depleted water column) or at the ocean end of Nitinat Lake (where oxygen and nitrate‐rich regions sometimes overlap with sulfide‐rich regions). Maximum phytoplankton levels near the surface are high in both winter and summer. A second peak in biological activity appears near the anoxic boundary, possibly as a result of sulfur‐oxidizing bacteria. Sulfate‐reducing bacteria are also present in anoxic water in both seasons and just above the oxic/anoxic interface in winter and just above the suboxic/anoxic interface in summer.
The relative significance of viral lysis and microzooplankton grazing as pathways of dimethylsulfoniopropionate (DMSP) cleavage: An Emiliania huxleyi culture study
Authors: Evans Claire , Kadner Susanne V. , Darroch Louise J. , Wilson William H. , Liss Peter S. , Malin Gillian
Published: July 2010

Dimethylsulfoniopropionate (DMSP) cleavage was investigated during culture studies of grazing by the microzooplankter Oxyrrhis marina and viral lysis by Emiliania huxleyi virus 86 (EhV‐86) on two axenic strains of E. huxleyi. The cleavage products of DMSP, dimethyl sulfide (DMS) and acrylic acid (AA), accumulated during viral infection of both strains, confirming that viral lysis of algae can lead directly to DMSP cleavage. AA and DMS accumulated in parallel with compromised E. huxleyi cells, indicating that DMSP cleavage occurred during the physical disruption of the infected cells. This is in agreement with the hypothesis that DMSP and DMSP lyase ([DL] the enzyme responsible for cleaving DMSP) are segregated in healthy or undamaged cells. During grazing, the concentrations of DMS and AA produced per eaten cell were an order of magnitude higher than the concentrations resulting from cell death caused by viral infection, suggesting that grazing is the quantitatively more significant pathway of DMS production in E. huxleyi. Levels of DL activity decreased in infected cultures to a minimum of 0.00065 fmol cell−1 min−1 as compared with an average of 0.09 fmol cell−1 min−1 in the control cultures, indicating that reduced DL activity in virally infected cells was responsible for the lower levels of DMSP cleavage observed during viral lysis.
Vitamin B12 and iron colimitation of phytoplankton growth in the Ross Sea
Authors: Bertrand Erin M. , Saito Mak A. , Rose Julie M. , Riesselman Christina R. , Lohan Maeve C. , Noble Abigail E. , Lee Peter A. , DiTullio Giacomo R.
Published: July 2010

Primary production in the Ross Sea, one of the most productive areas in the Southern Ocean, has previously been shown to be seasonally limited by iron. In two of three bottle incubation experiments conducted in the austral summer, significantly higher chlorophyll a (Chl a) concentrations were measured upon the addition of iron and B12, relative to iron additions alone. Initial bacterial abundances were significantly lower in the two experiments that showed phytoplankton stimulation upon addition of B12 and iron relative to the experiment that did not show this stimulation. This is consistent with the hypothesis that the bacteria and archaea in the upper water column are an important source of B12 to marine phytoplankton. The addition of iron alone increased the growth of Phaeocystis antarctica relative to diatoms, whereas in an experiment where iron and B12 stimulated total phytoplankton growth, the diatom Pseudonitzschia subcurvata went from comprising approximately 70% of the phytoplankton community to over 90%. Cobalt additions, with and without iron, did not alter Chl a biomass relative to controls and iron additions alone in the Ross Sea. Iron and vitamin B12 plus iron treatments caused reductions in the DMSP (dimethyl sulfoniopropionate) : Chl a ratio relative to the control and B12 treatments, consistent with the notion of an antioxidant function for DMSP. These results demonstrate the importance of a vitamin to phytoplankton growth and community composition in the marine environment.
Phylogenetic diversity in cadmium : phosphorus ratio regulation by marine phytoplankton
Authors: Finkel Z. V. , Quigg A. S. , Chiampi R. K. , Schofield O. E. , Falkowski P. G.
Published: July 2010

We examined the effect of irradiance and growth rate on cadmium : phosphorus ratio in five species of phytoplankton representing four different phylogenetic groups to determine the relative importance of growth rate, irradiance, and taxonomic differences on Cd : P ratios. Irradiance and growth rate are responsible for >2 orders of magnitude variation in the Cd : P of phytoplankton. Diatoms exhibit an increase; cyanobacteria, a decrease; and prasinophyte and dinoflagellate species, no functional response in Cd : P with increasing growth rate because of changes in irradiance. These results are consistent with a metabolic demand for Cd in diatoms and a metabolic sensitivity to Cd by cyanobacteria.
Air‐water exchange and vertical profiles of organic carbon in a subarctic fjord
Authors: Ruiz-Halpern Sergio , Sejr Mikael K. , Duarte Carlos M. , Krause-Jensen Dorte , Dalsgaard Tage , Dachs Jordi , Rysgaard Søren
Published: July 2010

In this article, we examine the air‐sea exchange of exchangeable organic carbon (OC) as well as the internal pools and sources within a subarctic fjord. Air‐water fluxes of OC ranged from an uptake of 22 ± 10 mmol C m−2 d−1 in winter to a release of 2 ± 8 mmol C m−2 d−1 in the fall, sizable compared to that of CO2 (average uptake of 136 mmol C m−2 d−1 for the fall and 2.6 ± 0.84 mmol C m−2 d−1 in the winter). The water column profiles of exchangeable dissolved organic carbon (EDOC) followed closely those of dissolved organic carbon (DOC), and EDOC represented, on average, about one‐third of DOC. The dynamic characteristic and active cycling of EDOC was evidenced by incubation experiments performed on each fjord compartment (sediment, water column, macroalgae) where sediments and macroalgae were found to be substantial sources and the water column acted as a strong sink of EDOC.
Dead in the water: The fate of copepod carcasses in the York River estuary, Virginia
Authors: Elliott David T. , Harris Courtney K. , Tang Kam W.
Published: July 2010

Using laboratory and field experiments we investigated three fates of copepod carcass organic matter in the York River estuary, Virginia: ingestion by planktivores (necrophagy), microbial decomposition, and removal by gravitational settling in the presence of turbulence (sinking). The ctenophore Mnemiopsis leidyi ingested live copepods and carcasses indiscriminately in feeding experiments. Microbial decomposition led to ca. 50% of carcass dry weight loss within 8 h after death. Carcass settling velocities in still water were ca. 0.1 cm s−1, implying short residence time (hours) in the shallow estuary. However, turbulent mixing kept carcasses in suspension much of the time, reducing sinking losses. Rates of carcass organic matter removal were combined in a simple mathematical model predicting the fate of estuarine copepod carcasses. When sinking was considered, it removed a large fraction of carcass organic matter (≥58% for copepodites, ≥ 35% for nauplii), with most of the remainder being removed by microbial decomposition. In the absence of sinking losses, necrophagy became proportionally more important in removing carcass organic matter (≥ 49%, except in summer).
High concentrations of mycosporine‐like amino acids and colored dissolved organic matter in the sea surface microlayer off the Iberian Peninsula
Authors: Tilstone Gavin H. , Airs ruth L. , Vicente Victor Martinez , Widdicombe Claire , Llewellyn Carole
Published: July 2010

Mycosporine‐like amino acids (MAAs), phytoplankton pigments, and inherent optical properties were analyzed in sea surface microlayer (SSM), near‐surface (0‐2 m), and subsurface (0–110 m) samples from stations off the Iberian Peninsula in June‐July 2005. During a visible surface slick, MAA concentrations reached 290 µg L−1 in the SSM, which correlated with an increase in abundance of the dinoflagellate, Prorocentrum micans (> 4000 cells mL−1) and covaried with low Ekman transport. High levels of colored dissolved organic material (CDOM) were also found in the SSM, and a prominent absorption shoulder between 300 and 340 nm was evident in the CDOM absorption spectra, indicative of MAAs in the dissolved fraction. Low CDOM slope ratios (SCDOM(275‐295) : (350‐400)) during the development of the surface slick suggest microbial production of CDOM, possibly exuded from the sudden proliferation in P. micans. In the absence of a well‐defined SSM, higher SCDOM(275–295) : (350–400) ratios were found, suggesting photobleaching of CDOM at the surface. The particulate absorption spectra of MAAs (aPMAA(λ)) were effective at absorbing ultraviolet (UV) radiation in a narrow spectral band between 310 and 350 nm. Since aCDOM(λ) exhibits an exponential rise in absorption in the UV and was high in the SSM and the subsurface compared with aPMAA (λ), CDOM would be the principal mechanism of UVA and B attenuation in the water column, providing an additional sunscreen to phytoplankton.
Processes affecting horizontal mixing and dispersion in Winam Gulf, Lake Victoria
Authors: Okely Patricia , Imberger Jö rg , Antenucci Jason P.
Published: July 2010

Several large rivers enter Winam Gulf, a large shallow semi‐enclosed embayment of Lake Victoria. Given the vast spatial scale of this embayment (1400 km2), horizontal transport of waterborne material plays a major role in determining its biochemical properties. To identify the dominant hydrodynamic characteristics of this horizontal transport, a combination of field data and three‐dimensional numerical modeling were employed to investigate effects due to variable wind forcing, riverine inflows, and interactions with the rest of Lake Victoria including astronomical tides and a complex bathymetry. Currents in the Gulf were oscillatory due to periodic wind and tidal forcing leading to surface seiching, with a residual circulation component. In the western region of the Gulf near the connection with Lake Victoria, substantial vertical and horizontal shear in the currents resulted in efficient horizontal dispersion with rates of up to 160 m2 s−1 simulated using numerical tracers. In the eastern region, however, rates of horizontal dispersion were reduced to around 12 m2 s−1. This spatial variability in hydrodynamic conditions underpins regional differences in ecological properties of Winam Gulf.
Flow effects on benthic grazing on phytoplankton by a Caribbean reef
Authors: Monismith Stephen G. , Davis Kristen A. , Shellenbarger Gregory G. , Hench James L. , Nidzieko Nicholas J. , Santoro Alyson E. , Reidenbach Matthew A. , Rosman Johanna H. , Holtzman Roi , Martens Christopher S. , Lindquist Niels L. , Southwell Melissa W. , Geninf Amatzia
Published: July 2010

We present measurements of flows and fluxes of phytoplankton to Conch Reef, Florida, a Caribbean reef dominated by sponges and soft corals, located in 15 m of water offshore of Key Largo. Vertical profiles of chlorophyll a, a proxy for phytoplankton biomass, showed a near‐bed depletion, indicating the existence of concentration boundary layers. Along with simultaneous measurements of velocity profiles, near‐bed turbulence, and temperature stratification, these profiles were used to compute α, the mass transfer velocity of phytoplankton to the bed (i.e., the flux to the bed normalized by near‐bed concentration). The α value ranged from ‐40 to +130 m d−1, with a significant linear positive relationship with shear velocity. The median value of α = 48 ± 20 m d−1 is larger than would be expected, given the observed population of filter‐feeding sponges. Nonetheless, these large values of a are consistent with values found recently for another coral reef as well as for a soft bottom estuarine community. Taken as a whole, these measurements indicate that reefs with large roughness and/or energetic currents should be able to support higher biomasses of benthic organisms than would low relief reefs or reefs in sluggish waters.
The Uneasy Case for the Personal Maintenance Deduction
Authors: Thornton Robert J. , Schwartz Eli
Published: July 2010

No abstract available.
Evaluating Household Services: Additional Evidence
Authors: Kiker B. F. , Heath Julia A.
Published: July 2010

No abstract available.
An Historical Simulation Approach to the Present Valuation of Future Earnings
Authors: Dulaney Ronald A.
Published: July 2010

No abstract available.
The Use of the Years of Dependency Formula in the Apportionment of Wrongful Death Settlements–Criticism and Modification
Authors: Franz Wolfgang W.
Published: July 2010

No abstract available.
Estimating Monetary Loss Due to Personal Injury
Authors: Marlin James W.
Published: July 2010

No abstract available.
Economic Damages – The Handbook for Plaintiff and Defense Attorneys
Authors: Slesnick Frank
Published: July 2010

No abstract available.
Recent Trends in Women's use of Time and their Implications for Assessing the Replacement Cost of Household Services
Authors: Leonesio Michael V.
Published: July 2010

No abstract available.
Effective roughness modelling as a tool for soil moisture retrieval from C- and L-band SAR
Authors: Lievens H. , Verhoest N. E. C. , De Keyser E. , Vernieuwe H. , Matgen P. , Álvarez-Mozos J. , De Baets B.
Published: July 2010

Abstract. Soil moisture retrieval from Synthetic Aperture Radar (SAR) using state-of-the-art backscatter models is not yet fully operational at present, mainly due to difficulties involved in the parameterisation of soil surface roughness. Recently, increasing interest has been drawn to the use of calibrated or effective roughness parameters, as they circumvent issues known to the parameterisation of field-measured roughness. This paper analyses effective roughness parameters derived from C- and L-band SAR observations over a large number of agricultural seedbed sites in Europe and furthermore shows that parameters may largely differ between SAR acquisitions, as they are related to the observed backscatter coefficients and variations in the local incidence angle. Therefore, a statistical model is developed that allows the estimation of effective roughness parameters from microwave backscatter observations. Subsequently, these parameters can be propagated through the Integral Equation Model (IEM) for soil moisture retrieval. It is shown that fairly accurate soil moisture results are obtained both at C- and L-band, with an RMSE ranging between 4 vol% and 6.5 vol%.
Connection of large earthquakes occurring moment with the movement of the Sun and the Moon and with the Earth crust tectonic stress character
Authors: Kachakhidze M. K. , Kiladze R. , Kachakhidze N. , Kukhianidze V. , Ramishvili G.
Published: July 2010

Abstract. It is acceptable that earthquakes certain exogenous (cosmic) triggering factors may exist in every seismoactive (s/a) region and in Caucasus among them. They have to correct earthquake occurring moment or play the triggering role in case when the region is at the limit of the critical value of the geological medium of course. Our aim is to reveal some exogenous factors possible to initiate earthquakes, on example of Caucasus s/a region, taking into account that the region is very complex by the point of view of the tectonic stress distribution. The compression stress directed from North to South (and vice versa) and the spread stress directed from East to West (and vice versa) are the main stresses acted in Caucasus region. No doubt that action of the smallest external stress may "work" as earthquakes triggering factor. In the presented work the Moon and the Sun perturbations are revealed as initiative agents of earthquakes when the directions of corresponding exogenous forces coincide with the directions of the compression stress or the spreading tectonic stress in the region.
Harnessing Surface Wrinkle Patterns in Soft Matter
Authors: Yang Shu , Khare Krishnacharya , Lin Pei‐Chun
Published: July 2010

Mechanical instabilities in soft materials, specifically wrinkling, have led to the formation of unique surface patterns for a wide range of applications that are related to surface topography and its dynamic tuning. In this progress report, two distinct approaches for wrinkle formation, including mechanical stretching/releasing of oxide/PDMS bilayers and swelling of hydrogel films confined on a rigid substrate with a depth‐wise modulus gradient, are discussed. The wrinkling mechanisms and transitions between different wrinkle patterns are studied. Strategies to control the wrinkle pattern order and characteristic wavelength are suggested, and some efforts in harnessing topographic tunability in elastomeric PDMS bilayer wrinkled films for various applications, including tunable adhesion, wetting, microfluidics, and microlens arrays, are highlighted. The report concludes with perspectives on the future directions in manipulation of pattern formation for complex structures, and potential new technological applications.
Bioinspired Structural Material Exhibiting Post‐Yield Lateral Expansion and Volumetric Energy Dissipation During Tension
Authors: Wang Lifeng , Boyce Mary C.
Published: July 2010

Nature has inspired the design of improved synthetic materials that achieve superior and more efficient mechanical performance. Here microstructures inspired by the inner nacreous layer of seashells are designed and their mechanical properties including stiffness, strength, and energy dissipation are computed using micromechanical analysis. The hierarchical mineral/polymer microstructure can be tailored to achieve not only stiffness and strength, but also lateral plastic expansion during tension providing a volumetric energy dissipation mechanism.
Colloidal Films That Mimic Cilia
Authors: Liu Fang , Ramachandran Dhanya , Urban Marek W.
Published: July 2010

Cilia are wavy hair‐like structures that extend outward from surfaces of various organisms. They are classified into two general categories, primary cilia, which exhibit sensing attributes, and motile cilia, which exert mechanical forces. A new poly(2‐(N,N‐dimethylamino)ethyl methacrylate‐co‐n‐butyl acrylate‐co‐N,N‐(dimethylamino) azobenzene acrylamide) (p(DMAEMA/nBA/DMAAZOAm) copolymer is prepared using colloidal synthesis, which, upon coalescence, form films capable of generating surfaces with cilia‐like features. While film morphological features allow the formation of wavy whiskers, the chemical composition of the copolymer facilitates chemical, thermal, and electromagnetic responses manifested by simultaneous shape and color changes as well as excitation wavelength dependent fluorescence. These studies demonstrate that synthetically produced polymeric films can exhibit combined thermal, chemical, and electromagnetic sensing leading to locomotive and color responses, which may find numerous applications in sensing devices, intelligent actuators, defensive mechanisms, and others.
Research on optimum heating system design for rapid thermal response mold with electric heating based on response surface methodology and particle swarm optimization
Authors: Wang Guilong , Zhao Guoqun , Guan Yanjin
Published: July 2010

A new electric‐heating rapid thermal response (RTR) mold with floating cavity/core for rapid heat cycle molding is investigated in this study. Process principles of Rapid heat cycle molding (RHCM) with such new electric‐heating mold are discussed and presented. Response surface methodology (RSM) is employed to develop mathematical relationships between layout of the heating elements and heating efficiency, temperature uniformity and structural strength of the floating cavity. Three explanatory variables including half distance between two adjacent heating rods, spacing between heating rods and cavity surface, and the diameter of the heating rod are used to describe the layout and scale of the heating elements. The response variables involving required heating time, maximum cavity surface temperature, and maximum von‐Mises stress are used to characterize heating efficiency, temperature uniformity, and structural strength of the floating cavity, respectively. Central composite design (CCD) method is used for factorial experiments. Finite element analyses are conducted for combination of explanatory parameters to acquire the corresponding values of the response variables. Three predictive models for the response variables are created by regression analysis. Analysis of variance (ANOVA) is used to check their accuracy. These response surface models are interfaced with an effective particle swarm algorithm for the optimum heating system design of the electric‐heating RTR mold. The developed optimum method is then used for the design of the floating electric‐heating cavity for an actual industrial product. The following heat transfer analysis results show that the temperature distribution uniformity of the cavity surface is greatly improved with the optimal cavity structure and layout of heating rods. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Rheological behavior in the molten state and solution of hyperbranched polyester of fourth and fifth generation
Authors: Murillo Edwin A. , Cardona Alvaro , López Betty L.
Published: July 2010

The rheological behavior in the molten state and solution of hyperbranched polyol polyesters (HBPs) obtained by one step (HBP4, HBP5), step by step (HBP4P, HBP5P), and combination of both (HBP1‐4, HBP1‐5) was studied. Under conditions of dynamic oscillatory shear, all HBPs presented a shear‐thinning behavior and under steady shear they showed a Newtonian behavior. Also, the steady shear viscosities decreased with increasing temperature. The behavior of HBPs was mainly viscous, except for the HBP4P that showed higher storage modulus and reduction of complex viscosity when increasing the angular frequency. The HBPs presented higher complex viscosity than steady shear and they did not follow the Cox‐Merz rule. The HBPs in solution presented a plateau region at shear rate lower than 40 s−1 but a shear‐thickening behavior at shear rate higher than 40 s−1. The viscosities of HBPs in solution (in the plateau region) and molten state increase in the following order: HBP5P > HBP1‐5 > HBP4P > HBP1‐4 > HBP4 > HBP5. These results are not in agreement with the values of the number average molar mass obtained by vapor pressure osmometry due to different interaction between HBPs molecules. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Morphology and tensile properties of polypropylene‐multiwalled carbon nanotubes composite fibers
Authors: Soitong Tawat , Pumchusak Jantrawan
Published: July 2010

In this work, we analyzed tensile properties of polypropylene‐multiwalled carbon nonotubes composite fibers. The multiwalled carbon nanotubes (MWCNTS) were used in different contents of 0, 1, 2, 3, 4, and 5 wt %. Dispersing agents were used to disperse MWCNTs in polypropylene matrix. After the dispersing agent was removed, the mixture was melt mixed. The fibers were spun by a home‐made melt spinning equipment and stretching was done at a draw ratio of 7.5. By using 1–5 wt % of MWCNTs, the modulus of composite fibers increased by 69–84% and tensile strength increased about 39% when compared with the virgin polypropylene fibers. In addition, the MWCNTs dispersion in the matrix was monitored by scanning electron microscopy and transmission electron microscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effects of long‐term etanercept treatment on growth in children with selected categories of juvenile idiopathic arthritis
Authors: Giannini Edward H. , Ilowite Norman T. , Lovell Daniel J. , Wallace Carol A. , Rabinovich C. Egla , Reiff Andreas , Higgins Gloria , Gottlieb Beth ,   Pediatric Rheumatology Collaborative Study Group, Chon Yun , Zhang Nan , Baumgartner Scott W.
Published: July 2010

Objective

To evaluate the effects of long‐term etanercept treatment, with or without methotrexate, on growth in children with selected categories of juvenile idiopathic arthritis (JIA).

Methods

We conducted a 3‐year, open‐label, nonrandomized registry of 594 patients with polyarticular or systemic JIA treated with etanercept only, etanercept plus methotrexate, or methotrexate only. Height, weight, and body mass index (BMI) were assessed at baseline and at years 1, 2, and 3, using percentiles derived from US Centers for Disease Control and Prevention standardized growth charts.

Results

Statistically significant increases in the mean height percentiles from baseline were observed in etanercept‐treated patients at year 3 (4.8 percentile points) and in patients treated with etanercept plus methotrexate at years 1, 2, and 3 (2.4, 3.3, and 5.6 percentile points, respectively). Statistically significant increases from baseline in the mean weight percentiles were observed at years 1, 2, and 3 in both the etanercept group (7.4, 10.0, and 13.0 percentile points) and the etanercept‐plus‐methotrexate group (2.9, 6.9, and 8.4 percentile points, respectively). Statistically significant increases from baseline in the mean BMI percentiles were observed in both the etanercept group (range 9.6–13.8 percentile points) and the etanercept‐plus‐methotrexate group (range 2.1–5.2 percentile points). The mean height, weight, and BMI percentiles did not change significantly in patients in the methotrexate‐only group.

Conclusion

Etanercept treatment, with or without methotrexate, may contribute to the restoration of normal growth in children with JIA.
Reduction in cadmium‐induced toxicity and c‐Jun N‐terminal kinase activation by glutathione in cultured mouse embryonic cells
Authors: MacKinnon Yolanda , Kapron Carolyn M.
Published: July 2010

INTRODUCTION

Cadmium (Cd2+) induces limb defects and other malformations in experimental animals. However, the mechanisms of the developmental toxicity of this metal are not fully understood. The ubiquitous intracellular tripeptide glutathione (GSH) protects nonembryonic cells from Cd2+‐induced cell death and is essential for normal embryonic development. We predicted that pretreatment with GSH would prevent cytotoxicity in cultured mouse embryonic limb bud cells exposed to Cd2+. Additionally, it was expected that GSH pretreatment would prevent the Cd2+‐induced activation of the signaling molecule c‐Jun N‐terminal kinase (JNK), which becomes phosphorylated upon exposure to Cd2+.

METHODS

Primary micromass cultures of limb bud cells obtained from organogenesis‐stage mouse embryos were treated with either Cd2+or GSH alone, or both Cd2+and GSH. Treatment with GSH commenced 4 hr prior to Cd2+treatment.

RESULTS

Cell proliferation was inhibited by approximately 50% after exposure to 4 μM Cd2+for 5 days. Cd2+treatment also resulted in a dose‐dependent increase in the intracellular GSH content as measured after 5 days of exposure. Pretreatment with 4 mM GSH for 4 hr prevented the Cd2+‐induced inhibition of cell proliferation and differentiation and also inhibited a threefold activation of JNK induced by 4 μM Cd2+after 24 and 48 hr of exposure.

CONCLUSION

Exogenous GSH protects cultured embryonic limb bud cells from Cd2+‐induced inhibition of cell proliferation and differentiation, which is associated with the activation of JNK. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
Perceptions of childfree women: The role of perceivers' and targets' ethnicity
Authors: Vinson Candice , Mollen Debra , Smith Nathan Grant
Published: July 2010

The purpose of this study was to examine the impact of ethnicity on perceptions of voluntary childfree women. We were interested in determining whether mothers were viewed as more stereotypically positive than women without children and how the ethnicity of the participant and the target impacted participants' ratings. We utilized vignettes and manipulated motherhood status and ethnicity of the target. Participants (n = 224) were comprised of female university students in the southwestern region of the United States. Results indicated that women view childfree women negatively. Moreover, women view African American mothers more favourably than childfree African American women. Results are discussed in terms of gender roles in communities of colour. Copyright © 2010 John Wiley & Sons, Ltd.
Insight into C35 terpene Biosyntheses by Nonpathogenic Mycobacterium Species: Functional Analyses of Three Z‐Prenyltransferases and Identification of Dehydroheptaprenylcyclines
Authors: Sato Tsutomu , Takizawa Kazuo , Orito Yuriko , Kudo Hanayo , Hoshino Tsutomu
Published: July 2010

Nonpathogenic Mycobacterium species produce rare cyclic C35 terpenes that are biosynthesized by cyclization of Z‐type C35 polyprenyl diphosphate. To provide deeper insight into the biosynthesis of C35 terpenes, we carried out functional analyses of three Z‐prenyltransferase homologues in M. vanbaalenii identified by genomic analysis. Mvan_3822, a novel bifunctional Z‐prenyltransferase, biosynthesizes C35‐heptaprenyl diphosphate as a main product from (E,E)‐farnesyl diphosphate (E,E‐FPP) and (E,E,E)‐geranylgeranyl diphosphate (E,E,E‐GGPP), but produces a C50‐decaprenyl diphosphate from geranyl diphosphate. Mvan_1705 is a novel Z,E,E‐GGPP synthase. In addition, novel cyclic C35 terpenes, (14E)‐ and (14Z)‐dehydroheptaprenylcycline, were identified as minor metabolites in nonpathogenic Mycobacterium cells. C35 terpenes could be biosynthesized by two routes, in which E and Z geometric isomers of heptaprenyl diphosphate are produced from E,E‐FPP and E,E,E‐GGPP, and the prenylreductase responsible for the biosynthesis of C35 terpenes could reduce both E and Z prenyl residues.
ChemInform Abstract: Facile and One Pot Synthetic Routes for Various Novel, Differently Fused and Promising Heteropolycycles.
Authors: Gupta Shallu , Gupta Poonam , Sachar Anand , Sharma R. L.
Published: July 2010

Functionalized pyridopyrimidines (IV), obtained by a four component cyclocondensation reaction, are convenient starting compounds for the synthesis of a variety of heteropolycycles.
ChemInform Abstract: Combinatorial Synthesis of Deoxyhexasaccharides Related to the Landomycin A Sugar Moiety, Based on an Orthogonal Deprotection Strategy.
Authors: Tanaka Hiroshi , Yamaguchi Sho , Yoshizawa Atsushi , Takagi Motoki , Shin‐ya Kazuo , Takahashi Takashi
Published: July 2010

A library of 16 hexasaccharides related to landomycin A is prepared, by the synthesis of eight distinct trisaccharides and selective β‐glycosylation between the glycosyl donors and acceptors.
Discretionary power of project managers in knowledge‐intensive firms and gender issues
Authors: Chasserio Stéphanie , Legault Marie‐Josée
Published: July 2010

The scarcity of women among highly qualified professionals in business‐to‐business information and communication technologies (ICT) in Europe and in North America has been noted as recently as the late 1990s (Panteli, Stack, Atkinson, & Ramsay, 1999). The organization and management of work in such firms is typically project‐based. This has many consequences, including: long working hours with fierce resistance to any reduction, unpaid overtime, high management expectations of employee flexibility to meet unanticipated client demands, and the need for employees to negotiate flexible work arrangements on a case‐by‐case basis with a project manager who often has much discretion on whether to accommodate such requests. We found that women are particularly disadvantaged in such a system, which could partly explain their under‐representation in such jobs. Copyright © 2010 ASAC. Published by John Wiley & Sons, Ltd.
Midterm outcomes in patients with intermediate‐sized hepatocellular carcinoma
Authors: Morimoto Manabu , Numata Kazushi , Kondou Masaaki , Nozaki Akito , Morita Satoshi , Tanaka Katsuaki
Published: July 2010

BACKGROUND:

To improve the efficacy of radiofrequency ablation (RFA) for the treatment of intermediate‐sized hepatocellular carcinomas (HCCs), the authors compared RFA combined with transcatheter arterial chemoembolization (TACE) to RFA alone.

METHODS:

The authors randomly assigned 37 patients with solitary HCCs (diameter, 3.1‐5.0 cm in the greatest dimension) to 2 groups: the TACE‐RFA group, in which the patients received TACE followed by RFA on the same day, and the RFA group, in which the patients received only RFA.

RESULTS:

Technical success was achieved after 1.4 ± 0.5 RFA sessions in the RFA group and after 1.1 ± 0.2 RFA sessions in the TACE‐RFA group (P < .01). The mean diameters of the longer and shorter axes of the RFA‐induced ablated areas were 50 ± 8.0 mm and 41 ± 7.1 mm, respectively, in the RFA group and 58 ± 13.2 mm and 50 ± 11.3 mm, respectively, in the TACE‐RFA group; the mean diameters of the shorter axes were significantly different (P = .012). The rates of local tumor progression at the end of the third year in the RFA and TACE‐RFA groups were 39% and 6%, respectively (P = .012). The 3‐year survival rates of the patients in the RFA and TACE‐RFA groups were 80% and 93%, respectively (P = .369).

CONCLUSIONS:

In patients with intermediate‐sized HCCs, RFA combined with TACE is more effective than RFA alone for extending the ablated area in fewer treatment sessions and for decreasing the local tumor progression rate. Cancer 2010. © 2010 American Cancer Society.