bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spring Mixing: Turbulence and Internal Waves during Restratification on the New England Shelf
Authors: MacKinnon J. A. , Gregg M. C. 
Published: January 2006

Abstract
Integrated observations are presented of water property evolution and turbulent microstructure during the spring restratification period of April and May 1997 on the New England continental shelf. Turbulence is shown to be related to surface mixed layer entrainment and shear from low-mode near-inertial internal waves. The largest turbulent diapycnal diffusivity and associated buoyancy fluxes were found at the bottom of an actively entraining and highly variable wind-driven surface mixed layer. Away from surface and bottom boundary layers, turbulence was systematically correlated with internal wave shear, though the nature of that relationship underwent a regime shift as the stratification strengthened. During the first week, while stratification was weak, the largest turbulent dissipation away from boundaries was coincident with shear from mode-1 near-inertial waves generated by passing storms. Wave-induced Richardson numbers well below 0.25 and density overturning scales of several meters were observed. Turbulent dissipation rates in the region of peak shear were consistent in magnitude with several dimensional scalings. The associated average diapycnal diffusivity exceeded 10−3 m2 s−1. As stratification tripled, Richardson numbers from low-mode internal waves were no longer critical, though turbulence was still consistently elevated in patches of wave shear. Kinematically, dissipation during this period was consistent with the turbulence parameterization proposed by MacKinnon and Gregg, based on a reinterpretation of wave–wave interaction theory. The observed growth of temperature gradients was, in turn, consistent with a simple one-dimensional model that vertically distributed surface heat fluxes commensurate with calculated turbulent diffusivities.
Near-Inertial Waves on the New England Shelf: The Role of Evolving Stratification, Turbulent Dissipation, and Bottom Drag
Authors: MacKinnon J. A. , Gregg M. C. 
Published: January 2006

Abstract
Energetic variable near-inertial internal waves were observed on the springtime New England shelf as part of the Coastal Mixing and Optics (CMO) project. Surface warming and freshwater advection tripled the average stratification during a 3-week observational period in April/May 1997. The wave field was dominated by near-inertial internal waves generated by passing storms. Wave evolution was controlled by a balance among wind stress, bottom drag, and turbulent dissipation. As the stratification evolved, the vertical structure of these near-inertial waves switched from mode 1 to mode 2 with associated changes in the magnitude and location of wave shear. The growth of mode-2 waves was attributable to a combination of changing wind stress forcing and a nonlinear coupling between the first and second vertical modes through quadratic bottom stress. To explore both forcing mechanisms, an open-ocean mixed layer model is adapted to the continental shelf. In this model, surface wind stress and bottom stress are distributed over the surface and bottom mixed layers and then projected onto orthogonal vertical modes. The model replicates the correct magnitude and evolving modal distribution of the internal waves and confirms that bottom stress can act to transfer energy between internal wave modes.
Driving Forces of Interleaving in the Baroclinic Front at the Equator
Authors: Kuzmina Natalia , Lee Jae Hak 
Published: January 2006

Abstract
The different types of instability in the equatorial β-plane approximation are analyzed by means of a 2D linear stability problem. The double-diffusive (DD) and diffusive/baroclinic (2D baroclinic and McIntyre) instabilities are shown not to develop if contours of the mean salinity/density have a parabolic, symmetrical-relative-to-the-equator shape. Using modeling results, an illustrative scheme of Equatorial Undercurrent (EUC) regions where different types of instability can develop is presented and subsequently applied to understand the driving forces of the intrusions observed in a closed spaced CTD section, located between the equator and 1°N. Long coherence intrusions are situated within two isopycnal layers, aligned to 25 (layer 1) and 26.3 (layer 2) σT, where the vertical shear is low. It was shown from the model that the layer-1 intrusions being observed in the midlayer of the EUC where the mean horizontal gradient of salinity is approximately constant are likely generated by a combined effect of DD instability and instability due to linear horizontal shear. The layer-2 intrusions being observed in the lower part of EUC where the mean salinity contours have a parabolic shape likely arise because of linear horizontal shear only, while double diffusion can be considered as an effect that increases the growth rate of unstable modes. Special attention is focused on two different parts of the EUC in the mixing of the thermocline. It is noted that the EUC only makes the mass transfer by long coherence intrusions in certain layers where the vertical shear is small. Conversely, the EUC contributes to the growth rate of unstable modes due to the horizontal linear shear.
Wind-Induced Circulation in Semienclosed Homogeneous, Rotating Basins
Authors: Sanay Rosario , Valle-Levinson Arnoldo 
Published: January 2006

Abstract
The wind-induced circulation over laterally varying bathymetry was investigated in homogeneous systems using the three-dimensional Regional Ocean Model System (ROMS). The investigation focused on the influence of the earth’s rotation on the lateral distribution of the flow, with particular emphasis on the transverse circulation. Along-basin wind stress with no rotation caused a circulation dominated by an axially symmetric transverse structure consisting of downwind flow over the shoals and upwind flow in the channel along the whole domain. Transverse circulation was important only at the head of the system where the water sank and reversed direction to move toward the mouth. The wind-induced flow pattern under the effects of the earth’s rotation depended on the ratio of the maximum basin’s depth h to the Ekman depth d. The solution tended to that described in a nonrotating system as h/d remained equal to or below 1. For higher values of h/d, the longitudinal flow was axially asymmetric. Maximum downwind flow was located over the right shoal (in the Northern Hemisphere, looking downwind). The transverse component of velocity described three gyres. The main gyre was clockwise (looking downwind) and occupied the entire basin cross section, as expected from the earth’s rotation and the presence of channel walls. The other two gyres were small and localized and were linked to the lateral distribution of the along-channel velocity component, which in turn was dictated by bathymetry. These results compared favorably with a limited set of observations and are expected to motivate future measurements.
Boundary Intensification of Vertical Velocity in a β-Plane Basin
Authors: Pedlosky Joseph , Spall Michael A. 
Published: January 2006

Abstract
The buoyancy-driven circulation of simple two-layer models on the β plane is studied in order to examine the role of beta in determining the magnitude and structure of the vertical motions forced in response to surface heating and cooling. Both analytical and numerical approaches are used to describe the change in circulation pattern and strength as a consequence of the planetary vorticity gradient. The physics is quasigeostrophic at lowest order but is sensitive to small nonquasigeostrophic mass fluxes across the boundary of the basin. The height of the interface between the two layers serves as an analog of temperature, and the vertical velocity at the interface consists of a cross-isopycnal velocity, modeled in terms of a relaxation to a prescribed interface height, as well as an adiabatic representation of eddy thickness fluxes parameterized as lateral diffusion of interface displacement. In the numerical model the lateral eddy diffusion of heat is explicitly represented by a resolved eddy field. In the plausibly more realistic case, when the lateral diffusion of buoyancy dominates the diffusion of momentum, the major vertical velocities occur at the boundary of the basin as in earlier f-plane studies. The effect of the planetary vorticity gradient is to intensify the sinking at the western wall and to enhance the magnitude of that sinking with respect to the f-plane models. The vertical mass flux in the Sverdrup interior exactly balances the vertical flux in the region of the strong horizontal transport of the western boundary current, leaving the net flux to occur in a very narrow region near the western boundary tucked well within the western boundary current. On the other hand, if the lateral diffusion of heat is arbitrarily and unrealistically eliminated, the vertical mass flux is forced to occur in the interior. The circulation pattern is extremely sensitive to small net inflows or outflows across the basin perimeter. The cross-basin flux determines the interface height on the basin’s eastern boundary and affects the circulation pattern across the entire basin.
Eulerian and Lagrangian Velocity Distributions in the North Atlantic
Authors: LaCasce J. H. 
Published: January 2006

AbstractVelocity probability density functions (PDFs) are calculated using data from subsurface current meters in the western North Atlantic Ocean. The PDFs are weakly, but significantly, non-Gaussian. They deviate from normality because of an excess of energetic events, and there are evidently more such events in the main thermocline than in the deep ocean. The PDFs are also compared with those obtained from subsurface floats in the same region. The PDFs are statistically indistinguishable so long as the float data are averaged in appropriately sized bins. Taking too-small bins yields overly Gaussian float PDFs, and taking too-large bins yields too-non-Gaussian PDFs. With this caveat, the Lagrangian and Eulerian PDFs agree, consistent with expectations from theory and previous numerical simulations.
Geostrophic Adjustment of an Isolated Diapycnal Mixing Event and Its Implications for Small-Scale Lateral Dispersion
Authors: Lelong M-Pascale , Sundermeyer Miles A. 
Published: January 2006

Abstract
In this first of two companion papers, the time-dependent relaxation of an isolated diapycnal mixing event is examined in detail by means of numerical simulations, with an emphasis on the energy budget, particle displacements, and their implications for submesoscale oceanic lateral dispersion. The adjustment and dispersion characteristics are examined as a function of the lateral extent of the event L relative to the Rossby radius of deformation R. The strongest circulations and horizontal displacements occur in the regime R/L ≈ O(1). For short times, less than an inertial period, horizontal displacements are radial. Once the adjustment is completed, displacements become primarily azimuthal and continue to stir fluid over several to tens of inertial periods. The cumulative effect of many such events in terms of the effective lateral dispersion that they induce is examined in the companion paper.
Ballooning of River-Plume Bulge and Its Stabilization by Tidal Currents
Authors: Isobe Atsuhiko 
Published: January 2006

Abstract
When freshwater debouches into an adjacent ocean, an anticyclonic eddy (bulge) is formed in front of the river mouth. It is well known that a bulge growing offshore (ballooning) hardly reaches a steady state in the absence of either ambient currents or wind forcing. This study provides a physical interpretation for the ballooning of river-plume bulges by conducting numerical experiments in which a river plume is induced by a coastal freshwater source. Part of the freshwater released to the model ocean undergoes inertial instability. Near-inertial oscillations are predominant when disturbances are not forced in ambient waters of the river plume. These isotropic disturbances are amplified by inertial instability, so that unstabilized freshwater can move in arbitrary directions. Thus, unstabilized freshwater does not need to move toward the coastal boundary current on the right-hand side of the river mouth. Freshwater unstabilized for a long time can stay in the bulge for a long time. Unstabilized freshwater accumulates gradually in the bulge, and so ballooning occurs. When the direction of disturbances is prescribed in ambient waters, unstabilized freshwater is forced to move in the same direction. Thereby, the motion of unstabilized freshwater is restricted in the alongshore direction when background disturbances are induced by alongshore tidal currents. It is therefore concluded that tidal currents play a role in stabilizing the offshore growth of river-plume bulges in coastal and shelf waters.
Acceleration of mesoderm development and expansion of hematopoietic progenitors in differentiating ES cells by the mouse Mix-like homeodomain transcription factor
Authors: Willey Stephen , Ayuso-Sacido Angel , Zhang Hailan , Fraser Stuart T. , Sahr Kenneth E. , Adlam Matthew J. , Kyba Michael , Daley George Q. , Keller Gordon , Baron Margaret H. 
Published: January 2006

AbstractThe cellular and molecular events underlying the formation and differentiation of mesoderm to derivatives such as blood are critical to our understanding of the development and function of many tissues and organ systems. How different mesodermal populations are set aside to form specific lineages is not well understood. Although previous genetic studies in the mouse embryo have pointed to a critical role for the homeobox gene Mix-like (mMix) in gastrulation, its function in mesoderm development remains unclear. Hematopoietic defects have been identified in differentiating embryonic stem cells in which mMix was genetically inactivated. Here we show that conditional induction of mMix in embryonic stem cell–derived embryoid bodies results in the early activation of mesodermal markers prior to expression of Brachyury/T and acceleration of the mesodermal developmental program. Strikingly, increased numbers of mesodermal, hemangioblastic, and hematopoietic progenitors form in response to premature activation of mMix. Differentiation to primitive (embryonic) and definitive (adult type) blood cells proceeds normally and without an apparent bias in the representation of different hematopoietic cell fates. Therefore, the mouse Mix gene functions early in the recruitment and/or expansion of mesodermal progenitors to the hemangioblastic and hematopoietic lineages.
GABAergic Signaling at Mossy Fiber Synapses in Neonatal Rat Hippocampus
Authors: Safiulina Victoria F. , Fattorini Giorgia , Conti Fiorenzo , Cherubini Enrico 
Published: January 2006

In the adult rat hippocampus, granule cell mossy fibers (MFs) form excitatory glutamatergic synapses with CA3 principal cells and local inhibitory interneurons. However, evidence has been provided that, in young animals and after seizures, the same fibers can release in addition to glutamate GABA. Here we show that, during the first postnatal week, stimulation of granule cells in the dentate gyrus gave rise to monosynaptic GABAA-mediated responses in principal cells and in interneurons. These synapses were indeed made by MFs because they exhibited strong paired-pulse facilitation, high sensitivity to the metabotropic glutamate receptor agonistl-AP-4, and short-term frequency-dependent facilitation. MF responses were potentiated by blocking the plasma membrane GABA transporter GAT-1 with NO-711 or by allosterically modulating GABAAreceptors with flurazepam. Chemical stimulation of granule cell dendrites with glutamate induced barrages of GABAA-mediated postsynaptic currents into target neurons. Furthermore, immunocytochemical experiments demonstrated colocalization of vesicular GABA transporter with vesicular glutamate transporter-1 and zinc transporter 3, suggesting that GABA can be taken up and stored in synaptic vesicles of MF terminals.Additional fibers releasing both glutamate and GABA into principal cells and interneurons were recruited by increasing the strength of stimulation. Both the GABAergic and the glutamatergic component of synaptic currents occurred with the same latency and were reversibly abolished byl-AP-4, indicating that they originated from the MFs. GABAergic signaling may play a crucial role in tuning hippocampal network during postnatal development. Low-threshold GABA-releasing fibers may undergo elimination, and this may occur when GABA shifts from the depolarizing to the hyperpolarizing direction.
Alternative Logics in Action: Water Management in the Andes
Authors: Holben Symantha A. 
Published: January 2006

Water and Power in Highland Peru: The Cultural Politics of Irrigation and Development. Paul H. Gelles. New Brunswick, NJ: Rutgers University Press, 2000.Water Rights and Empowerment. Rutgerd Boelens and Paul Hoogendam. eds. The Netherlands: Van Gorcum, 2002.
Snf1-Dependent and Snf1-Independent Pathways of Constitutive ADH2 Expression in Saccharomyces cerevisiae
Authors: Voronkova Valentina , Kacherovsky Nataly , Tachibana Christine , Yu Diana , Young Elton T 
Published: January 2006

Abstract
The transcription factor Adr1 directly activates the expression of genes encoding enzymes in numerous pathways that are upregulated after the exhaustion of glucose in the yeast Saccharomyces cerevisiae. ADH2, encoding the alcohol dehydrogenase isozyme required for ethanol oxidation, is a highly glucose-repressed, Adr1-dependent gene. Using a genetic screen we isolated &gt;100 mutants in 12 complementation groups that exhibit ADR1-dependent constitutive ADH2 expression on glucose. Temperature-sensitive alleles are present among the new constitutive mutants, indicating that essential genes play a role in ADH2 repression. Among the genes we cloned is MOT1, encoding a repressor that inhibits TBP binding to the promoter, thus linking glucose repression with TBP access to chromatin. Two genes encoding proteins involved in vacuolar function, FAB1 and VPS35, and CDC10, encoding a nonessential septin, were also uncovered in the search, suggesting that vacuolar function and the cytoskeleton have previously unknown roles in regulating gene expression. Constitutive activation of ADH2 expression by Adr1 is SNF1-dependent in a strain with a defective MOT1 gene, whereas deletion of SNF1 did not affect constitutive ADH2 expression in the mutants affecting vacuolar or septin function. Thus, the mutant search revealed previously unknown Snf1-dependent and -independent pathways of ADH2 expression.
Inhibitory Effects of Mizolastine on Ultraviolet B‐Induced Leukotriene B4 Production and 5‐Lipoxygenase Expression in Normal Human Dermal Fibroblasts In Vitro
Authors: Yan Yan , Wang Baoxi , Zuo Ya‐gang , Qu Tao 
Published: January 2006

ABSTRACTUltraviolet B (UVB) irradiation exerts hazardous effects such as acute photodamage, skin cancer and photoaging. In this study we evaluated the protective effects of a nonsedative histamine H1‐receptor antagonist, mizolastine, on UVB‐exposed skin dermal fibroblasts. Therefore, primary human skin fibroblasts were incubated with mizolastine or dexamethasone after 100 mJ/cm2 UVB irradiation. Leukotriene B4 (LTB4) in fibroblast supernatants was detected with enzyme immunoassays, expression of 5‐lipoxygenase (5‐LOX) messenger RNA (mRNA) in skin fibroblasts was examined by reverse transcriptase‐polymerase chain reaction and expression of 5‐LOX protein was measured by immune blotting and immunofluorescent staining with rabbit anti‐human 5‐LOX antibody. It was found that 0.01 mM mizolastine inhibited UVB‐induced LTB4 production from skin fibroblasts at 12, 24 and 36 h. Meanwhile, mizolastine down‐regulated 5‐LOX mRNA expression and inhibited 5‐LOX translocation from nucleus to cytoplasm in fibroblasts. On the basis of these findings, we propose that mizolastine might play a protective role in the pathogenesis of UV radiation‐induced acute photodamage of the skin.
Polycarbonates
Authors: Brunelle Daniel J. 
Published: January 2006

AbstractPolycarbonates are an unusual and extremely useful class of high heat polymers known for their toughness and clarity. The vast majority of polycarbonates are based on bisphenol A (BPA), and sold under the trade names Lexan (GE), Makrolon (Bayer), Caliber (Dow), Panlite (Teijin), and Iupilon (Mitsubishi). BPA polycarbonates have glass transition temperatures (Tg) in the range of 140–155°C, and are widely regarded for their optical clarity and exceptional impact resistance and ductility at or below room temperature. Other properties such as modulus, dielectric strength, and tensile strength are comparable to other amorphous thermoplastics at similar temperatures below their respectiveTgs. However, whereas most amorphous polymers are stiff and brittle below theirTgs, polycarbonates retain their ductility. Polycarbonates are prepared commercially by two completely different processes: Schotten–Baumann reaction of phosgene and an aromatic diol in an amine‐catalyzed interfacial condensation reaction, or via base‐catalyzed transesterification of a bisphenol with a monomeric carbonate such as diphenyl carbonate. Each process has its own inherent advantages and disadvantages. Many important products are also based on polycarbonate in blends with other materials, copolymers, branched resins, flame‐retardant compositions, foams, and other materials. Polycarbonates are produced with global manufacture currently just over 2 million tons annually. Polycarbonates are also the object of both industrial and academic research, due to its widespread utility and unusual properties. Research on polycarbonates has steadily increased over the past two decades, with over 5000 publications on the topic since 1995, and nearly 20,000 patents having appeared globally, more than 8000 since 1995. Polycarbonates have been the subject of three monographs, once of them published in 2000. This paper gives a brief overview of polycarbonates.
Superabsorbent Polymers
Authors: Buchholz Fredric L. 
Published: January 2006

Abstract
Superabsorbent polymers are very high molecular mass, cross‐linked polyelectrolytes that can absorb more than 10 times their mass of water or aqueous solutions. The commercially available superabsorbent polymers are alkali metal salts of poly(acrylic acid) cross‐linked with multifunctional monomers. The polymers are usually made by means of free‐radical‐initiated polymerization of an aqueous solution of the monomers, followed by drying the resulting hydrogel, and grinding the dry polymers to a granular powder. The principal use of superabsorbent polymers is as a liquid absorbent in baby diapers, feminine hygiene products, and adult incontinence products. Smaller volumes are used in food packaging and in water‐blocking tapes for electrical and telecommunication cables.
On the design of crystallization‐based separation processes: Review and extension
Authors: Cisternas Luis A. , Vásquez Cristian M. , Swaney Ross E. 
Published: January 2006

AbstractAn analysis is given of various aspects of the design of crystallization‐based separation processes. A literature review is included for each of the different themes treated in the study. Special emphasis is placed on the usefulness of the relative composition diagram as a tool for identification of possible flow sheets for separations based on fractional crystallization. A series of rules are derived that may be of practical value in the use of the relative composition diagram. Illustrative examples are included that present the advantages and limitations of this methodology. Results are compared with those obtained from the literature where available. © 2006 American Institute of Chemical Engineers AIChE J, 2006