bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Sulfonated Lignin Dispersants by Hydrophobic Interactive Chromatography
Authors: Winowiski T , Lebo S , Gretland K , Gustafsson J
Published: August 2005

Organic surfactants can be produced by sulfonation of lignin that naturally occurs in the structural tissue of plants. These sulfonated lignins often exist as a heterogeneous mixture that is difficult to analyze by conventional means. It is believed that molecular weight and degree of sulfonation impact the hydrophobic balance and subsequent performance of lignin dispersants, but analytical measurements of these properties typically report an average value and give little or no detail about heterogeneity. Each component of this mixture will impart a unique quality to the dispersant and its subsequent effect in the formulation. Hydrophobic Interactive Chromatography (HIC) is useful in separating and characterizing various components of lignin dispersants based on hydrophobic response. For example, Borresperse NA (BNA-6.0) has a high percentage of hydrophilic material that elutes quickly from the column. In contrast, Lignosperse AGO-300 (OXY-2.6) elutes much later and has a strong hydrophobic peak. Both have overlapping middle peaks. These two dispersants are completely water soluble, although their dissolution rates differ. However, significant portions of OXY-2.6 are not soluble in 32-0-0 liquid fertilizer. The fractional percentage of dispersant that remains insoluble in 32-0-0 is predicted by HIC.
Influence of Adjuvants on Weed Control from Tribenuron
Authors: Zollinger RK
Published: August 2005

Tribenuron is a slow acting sulfonylurea herbicide that becomes more soluble as spray solution pH increases. Data from field research show differences in adjuvant enhancement of tribenuron. The most effective adjuvants with tribenuron were methylated seed oil and basic pH blend adjuvants, but the greatest activity occurred when applied together. The order of tribenuron enhancement from adjuvants was: methylated seed oil & basic pH blend>methylated seed oil=basic pH blend>crop oil concentrate=nonionic surfactant & organosilicone>nonionic surfactant=nonionic surfactant&water conditioner>nonionic surfactant&organosilicone. Methylated seed oil & basic pH blend adjuvant did not entirely overcome tribenuron antagonism of quizalofop. Tribenuron, applied as a soluble granule (SG) formulation and having properties to increase spray solution pH, provided similar weed control at a reduced rate as compared to the commercial extruded paste (XP) formulation of tribenuron. Limited research suggests that applying adjuvants on an area basis provides greater adjuvant enhancement than if applied on a percent volume basis. This would be especially important as spray volume decreases. These results generally support the concept that herbicide solubilization and absorption are necessary to maximize foliar activity.
Nozzle Formulation Interactions: Consequences for Spray Droplet Adhesion to Plant Surfaces
Authors: Downer RA , Hacker JK , Ebert RS
Published: August 2005

Tests were conducted with a widely used herbicide (glyphosate) that is available in a range of formulations and a selection of commonly used nozzle types [XR TeeJet, extended range flat spray tip (XR), Turbo TeeJet, wide angle flat spray tip (TT), AI TeeJet, Air Induction spray tip (AI)] and determined the rebound characteristics of each combination using a difficult-to-wet foliar crop target (cabbage), an easy-to-wet hairy weed (velvetleaf), and a difficult-to-wet weed (lambsquarters). The rebound was determined under standard spraying conditions in a track room using a “bounce chamber” constructed at The Laboratory for Pest Control Application Technology (LPCAT). The amount of spray liquid retained and reflected from the leaf surfaces was determined by weight. The data showed that there were no significant differences between the nozzles, but that formulation differences did occur and were a reflection of surfactant level in the spray mixture. There was a significant formulation X leaf interaction and leaf X nozzle interaction, but not a formulation X nozzle interaction.
SED Method of Measuring Yield Strength of Adhesives and Other Materials
Authors: Lenwari A , Albrecht P , Albrecht M
Published: August 2005

The strain energy density (SED) method of determining the yield strength of adhesives and other materials that is based on the fundamental principles of mechanics is described in this paper. The results from two sets of tests are reported. In the first set, the yield strength of multiple specimens made of the adhesive FM 300K was determined in the dry/cold, moderate, and humid/hot environments; the strain rates were 10−2/s, 10−4/s, and 10−6/s. In the second set, single specimens of five other adhesives were tested in the dry/cold and humid/hot environments; the strain rate was 10−4/s. Fifty-three out of the 60 specimens have yield strengths calculated with the SED method that are equal to or lower than the values obtained with the 0.2% offset method suggested in the ASTM specifications. The SED method is most valuable when the stress-strain curve of the material exhibits a gradual transition from elastic to the inelastic behavior typical of polymers, aluminum, and some very high strength steels. To ensure the safety of bonded structures, the yield strength of adhesives should be determined with the SED method, which is based on the fundamental principles of mechanics, instead of on an arbitrary estimate of strain offset. Although applied in this paper to stress-strain curves of adhesives, the SED method may also discern the onset of yielding and instability in columns and beams. To ensure that the yield strength of adhesives for bonding load-bearing structures is not systematically overestimated, the authors recommend using the SED method in lieu of the 0.2% offset method.
Analysis of Gasoline and Diesel Fuel Samples by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Using Pneumatic Nebulizer and Standard Spray Chamber
Authors: Onyeso CC
Published: August 2005

A method has been developed for accurate quantitative determination of additive elements and wear metals in gasoline and diesel fuel in the concentration range of 0 to 50 ppm using inductively coupled plasma atomic emission spectrometry (ICP-AES). This method requires an ICP capable of detecting metals at the 0.02 mg/kg level, and capable of linear calibration over the range of 0.05 to 20.0 mg/kg with a correlation coefficient of 0.9999 or better. No additional ICP-AES accessory or lengthy sample preparation is required. The PerkinElmer Optima 4300 has been shown to meet this requirement.
The Application of Ti-15Mo Beta Titanium Alloy in High Strength Structural Orthopaedic Applications
Authors: Jablokov VR , Nutt MJ , Richelsoph ME , Freese HL
Published: August 2005

Titanium-15Molybdenum beta titanium alloy is a generic alloy that has been around for a long time, but has never found wide use in the aerospace industry. Beta titanium alloys, in general, and corrosion-resistant biocompatible titanium alloys, in particular, attracted a lot of attention in the medical and surgical device industry in the late 1980s and early 1990s. Until that time, all of the titanium grades used for medical implant applications were based on ASTM “F” standards modeled from aerospace industry and AMS specifications. The CP titanium grades (CP-1, CP-2, and CP-4) and two α + β alloys, Ti-6Al-4V ELI and Ti-6Al-4V, were widely used in aerospace applications and found early acceptance to become the reference metallic materials in ASTM F 748. Two important factors held Ti-15Mo back from commercial applications and use: the physical metallurgy of the alloy and the inability of the then-current reactive metals melting and processing machinery to handle this unusual binary alloy. This paper will briefly review high-technology manufacturing advances and processing technology that have enabled the reliable production of large-scale lots of Ti-15Mo bar and rod product forms. Additionally, mechanical and metallurgical data for semi-finished high strength rod product suitable for highly stressed orthopaedic implant applications will be presented.
An Automatic Pavement Surface Distress Inspection System
Authors: Huang Y , Xu B
Published: August 2005

This paper presents a customized image-processing algorithm for the high-speed and real-time detection of pavement surface distresses. The algorithm was developed based on the “grid cell” analysis, in which a pavement image is divided into a grid of 8 × 8 pixel cells, and each cell is classified as a non-crack cell or a crack cell based on the statistics of the grayscales of the cell pixels. A crack cell can be regarded as a seed for crack formation. Adjacent crack seeds or seed clusters are connected to a crack segment. Each segment has it own direction and contrast traced from all seed in the path. A full crack is a connection of nearby segments with similar directions and contrasts. Most importantly, there must be a clear crack path along these segments. Because many operations are performed on the grid cells rather than on the original image, the algorithm can detect the cracks in the current image during the time when the camera is capturing a new image. Therefore, the survey can run at real time at a highway speed. The trial test results showed a good repeatability and accuracy when the system conducts multiple surveys and runs at different speeds and different weather conditions.
Reducing Tin and Aminosilane Concentration in Silicone Elastomeric Coating to Improve Its Durability
Authors: Cai Y
Published: August 2005

This study evaluated the impacts of tin and amino-functional silane on the long-term durability of a silicone coating material.

An experimental design was applied. Tin and aminosilane's concentrations were the variables. Laboratory-made samples were tested for initial mechanical properties. Samples were further placed in the QUV accelerated weathering chamber (fluorescent UV and condensation method) and tested periodically for tensile and elongation properties within the durability evaluation.

Based on the observations of the material and the measurements of mechanical properties, the concentration of tin in the formulation has the most influential impact on durability. The higher the concentration of tin, the faster the chalking. The concentration of the aminosilane also showed similar impacts on the durability, but not as significant as tin.

This study suggested that it is feasible to reduce both tin and aminosilane's amount by 30 % without significant impacts on the material's properties, and this may improve the coating's durability by more than 50 %. This finding may also apply to silicone sealant and adhesives.
Designing and Specifying Self-Adhering Flashings for the Window-Wall Interface
Authors: Bateman R
Published: August 2005

Self-adhering flashings provide a flexible and durable material that conforms to various wall planes, particularly those occurring in recessed wall openings. New flashing methods for the window-wall interface are available for this material. These new methods for designers are illustrated with step-by-step installation details for recessed windows, flush wall openings, recessed sills, and sill pan flashings. Considerations for flashing the window-wall interface are presented. A guide specification for self-adhering flashings is included for specifiers.
New Chemical Antistripping Additives for Bituminous Mixtures
Authors: Abo-Qudais S , Walid Mulqi M
Published: August 2005

The main objective of this study was to develop new, low cost, chemical antistripping additives that have low negative effects on Hot-Mix Asphalt (HMA) properties such as stability and low temperature cracking potential. To achieve this objective, HMA specimens were prepared using limestone aggregate, asphalt with 80/100 penetration, and different types of chemical antistripping compounds. Eighteen different low cost chemical compounds were prepared and added to the HMA at different percentages. The effect of 28 different combinations of additive types and amounts on the HMA stripping was evaluated using the modified Texas Boiling Test. The results indicated that out of the 28 evaluated combinations of additive type and amount, five combinations caused a negative or no impact on stripping resistance. On the other hand, twelve additive combinations show relatively small improvements in stripping resistance. Another 11 additive combinations showed a positive effect on stripping resistance. Five of these 11 additives showed a high positive improvement in the stripping resistance (increase in coating areas was greater than 20%). However, of these five additives, four caused a high reduction in the asphalt ductility and penetration, while the fifth one (Aluminum mono-stearate) caused a small reduction in ductility and an insignificant change in penetration. This suggests that this additive is suitable for use as an antistripping agent.

The effects of antistripping additives in improving stripping resistance may be explained by the formation of strong links between the metal surfactant and with both the aggregate and asphalt. The stripping resistance of metal surfactants derived from the saponification reaction between the metal hydroxide [Ca(OH)2 and Al(OH)3] and the triglyceride of stearic acid was less than those derived from pure stearic acid (by neutralizing the stearic acid with the metal hydroxides). This may be explained by the presence of glycerol in the metal surfactants derived from the saponification reaction. Since glycerol contains three hydroxyl groups, it makes strong hydrogen bonding with water and appreciable interaction with the metal surfactant due to the presence of dipole-dipole forces. Accordingly, some of the metal surfactant and its attached asphalt are leached out during the boiling test producing a lower anti stripping effect.
Bidirectional Modulation of Hippocampal Long-Term Potentiation under Stress and No-Stress Conditions in Basolateral Amygdala-Lesioned and Intact Rats
Authors: Korz Volker , Frey Julietta U.
Published: August 2005

Hippocampal long-term potentiation (LTP) is widely considered as a cellular model for learning and memory formation. We have shown previously that protein synthesis-independent, early dentate gyrus (DG) LTP, lasting ∼4-5 h, can be transformed into a late-LTP with a duration of ≥24 h by a brief acute swim stress experience (high-stress condition). This reinforcement requires the activation of mineralocorticoid receptors and protein synthesis. The basolateral amygdala (BLA) is known to modulate glucocorticoid effects on the consolidation of spatial/contextual memory via a β-adrenergic mechanism. Interestingly, hippocampal DG-LTP can also be indirectly modulated by β-adrenergic and cholinergic/muscarinergic processes. Here, we show that the reinforcement of early-DG-LTP under high-stress conditions depends on the processing of novel spatial/contextual information. Furthermore, this reinforcement was blocked in BLA-lesioned animals compared with sham-operated and intact controls; however, it was not dependent on β-adrenergic or cholinergic/muscarinergic receptor activation. In contrast, under low-stress conditions, the induction of late-LTP in BLA-lesioned animals is facilitated, and this facilitation, again, was dependent on β-adrenergic activation. The data suggest that DG-LTP maintenance can be influenced by the BLA through different mechanisms: a short-lasting corticosterone-dependent and β-adrenergic-independent mechanism and a long-lasting mechanism that facilitated hippocampal β-adrenergic mechanisms.
Imaging Experimental Cerebral MalariaIn Vivo: Significant Role of Ischemic Brain Edema
Authors: Penet Marie-France , Viola Angèle , Confort-Gouny Sylviane , Le Fur Yann , Duhamel Guillaume , Kober Frank , Ibarrola Danielle , Izquierdo Marguerite , Coltel Nicolas , Gharib Bouchra , Grau Georges E. , Cozzone Patrick J.
Published: August 2005

The firstin vivomagnetic resonance study of experimental cerebral malaria is presented. Cerebral involvement is a lethal complication of malaria. To explore the brain of susceptible mice infected withPlasmodium bergheiANKA, multimodal magnetic resonance techniques were applied (imaging, diffusion, perfusion, angiography, spectroscopy). They reveal vascular damage including blood-brain barrier disruption and hemorrhages attributable to inflammatory processes. We provide the firstin vivodemonstration for blood-brain barrier breakdown in cerebral malaria. Major edema formation as well as reduced brain perfusion was detected and is accompanied by an ischemic metabolic profile with reduction of high-energy phosphates and elevated brain lactate. In addition, angiography supplies compelling evidence for major hemodynamics dysfunction. Actually, edema further worsens ischemia by compressing cerebral arteries, which subsequently leads to a collapse of the blood flow that ultimately represents the cause of death. These findings demonstrate the coexistence of inflammatory and ischemic lesions and prove the preponderant role of edema in the fatal outcome of experimental cerebral malaria. They improve our understanding of the pathogenesis of cerebral malaria and may provide the necessary noninvasive surrogate markers for quantitative monitoring of treatment.
Mechanisms of Neuropeptide Y, Peptide YY, and Pancreatic Polypeptide Inhibition of Identified Green Fluorescent Protein-Expressing GABA Neurons in the Hypothalamic Neuroendocrine Arcuate Nucleus
Authors: Acuna-Goycolea Claudio , Tamamaki Nobuaki , Yanagawa Yuchio , Obata Kunihiko , van den Pol Anthony N.
Published: August 2005

The fast inhibitory transmitter GABA is robustly expressed in the arcuate nucleus (ARC) and appears to play a major role in hypothalamic regulation of endocrine function and energy homeostasis. Previously, it has not been possible to record selectively from GABA cells, because they have no defining morphological or physiological characteristics. Using transgenic mice that selectively express GFP (green fluorescent protein) in GAD67 (glutamic acid decarboxylase 67)-synthesizing cells, we identified ARC GABA neurons (n> 300) and used whole-cell recording to study their physiological response to neuropeptide Y (NPY), the related peptide YY3-36(PYY3-36), and pancreatic polypeptide (PP), important modulators of ARC function. In contrast to other identified ARC cells in which NPY receptor agonists were reported to generate excitatory actions, we found that NPY consistently reduced the firing rate and hyperpolarized GABA neurons including neuroendocrine GABA neurons identified by antidromic median eminence stimulation. The inhibitory NPY actions were mediated by postsynaptic activation of G-protein-linked inwardly rectifying potassium (GIRK) and depression of voltage-gated calcium currents via Y1and Y2receptor subtypes. Additionally, NPY reduced spontaneous and evoked synaptic glutamate release onto GABA neurons by activation of Y1and Y5receptors. The peptide PYY3-36, a peripheral endocrine signal that can act in the brain, also inhibited GABA neurons, including identified neuroendocrine cells, by activating GIRK conductances and depressing calcium currents. The endogenous Y4agonist PP depressed the activity of GABA-expressing neurons mainly by presynaptic attenuation of glutamate release. Together, these results show that the family of neuropeptide Y modulators reduces the activity of inhibitory GABA neurons in the ARC by multiple presynaptic and postsynaptic mechanisms.
Blocking Caspase Activity Prevents Transsynaptic Neuronal Apoptosis and the Loss of Inhibition in Lamina II of the Dorsal Horn after Peripheral Nerve Injury
Authors: Scholz Joachim , Broom Daniel C. , Youn Dong-Ho , Mills Charles D. , Kohno Tatsuro , Suter Marc R. , Moore Kimberly A. , Decosterd Isabelle , Coggeshall Richard E. , Woolf Clifford J.
Published: August 2005

We show that transsynaptic apoptosis is induced in the superficial dorsal horn (laminas I-III) of the spinal cord by three distinct partial peripheral nerve lesions: spared nerve injury, chronic constriction, and spinal nerve ligation. Ongoing activity in primary afferents of the injured nerve and glutamatergic transmission cause a caspase-dependent degeneration of dorsal horn neurons that is slow in onset and persists for several weeks. Four weeks after spared nerve injury, the cumulative loss of dorsal horn neurons, determined by stereological analysis, is >20%. GABAergic inhibitory interneurons are among the neurons lost, and a marked decrease in inhibitory postsynaptic currents of lamina II neurons coincides with the induction of apoptosis. Blocking apoptosis with the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD) prevents the loss of GABAergic interneurons and the reduction of inhibitory currents. Partial peripheral nerve injury results in pain-like behavioral changes characterized by hypersensitivity to tactile or cold stimuli. Treatment with zVAD, which has no intrinsic analgesic properties, attenuates this neuropathic pain-like syndrome. Preventing nerve injury-induced apoptosis of dorsal horn neurons by blocking caspase activity maintains inhibitory transmission in lamina II and reduces pain hypersensitivity.
Phosphorylation of Synapsin I by cAMP-Dependent Protein Kinase Controls Synaptic Vesicle Dynamics in Developing Neurons
Authors: Bonanomi Dario , Menegon Andrea , Miccio Annarita , Ferrari Giuliana , Corradi Anna , Kao Hung-Teh , Benfenati Fabio , Valtorta Flavia
Published: August 2005

In developing neurons, synaptic vesicles (SVs) undergo cycles of exo-endocytosis along isolated axons. However, it is currently unknown whether SV exocytosis is regulated before synaptogenesis. Here, we show that cAMP-dependent pathways affect SV distribution and recycling in the axonal growth cone and that these effects are mediated by the SV-associated phosphoprotein synapsin I. The presence of synapsin I on SVs is necessary for the correct localization of the vesicles in the central portion of the growth cone. Phosphorylation of synapsin I by cAMP-dependent protein kinase (protein kinase A) causes the dissociation of the protein from the SV membrane, allowing diffusion of the vesicles to the periphery of the growth cone and enhancing their rate of recycling. These results provide new clues as to the bases of the well known activity of synapsin I in synapse maturation and indicate that molecular mechanisms similar to those operating at mature nerve terminals are active in developing neurons to regulate the SV life cycle before synaptogenesis.
Dopamine Is a Regulator of Arousal in the Fruit Fly
Authors: Kume Kazuhiko , Kume Shoen , Park Sang Ki , Hirsh Jay , Jackson F. Rob
Published: August 2005

Sleep and arousal are known to be regulated by both homeostatic and circadian processes, but the underlying molecular mechanisms are not well understood. It has been reported that theDrosophilarest/activity cycle has features in common with the mammalian sleep/wake cycle, and it is expected that use of the fly genetic model will facilitate a molecular understanding of sleep and arousal. Here, we report the phenotypic characterization of aDrosophilarest/activity mutant known asfumin(fmn). We show thatfmnmutants have abnormally high levels of activity and reduced rest (sleep); genetic mapping, molecular analyses, and phenotypic rescue experiments demonstrate that these phenotypes result from mutation of theDrosophila dopamine transportergene. Consistent with the rest phenotype,fmnmutants show enhanced sensitivity to mechanical stimuli and a prolonged arousal once active, indicating a decreased arousal threshold. Strikingly,fmnmutants do not show significant rebound in response to rest deprivation as is typical for wild-type flies, nor do they show decreased life span. These results provide direct evidence that dopaminergic signaling has a critical function in the regulation of insect arousal.
Use-Dependent Inhibition of P2X3Receptors by Nanomolar Agonist
Authors: Pratt Emily B. , Brink Thaddeus S. , Bergson Pamela , Voigt Mark M. , Cook Sean P.
Published: August 2005

P2X3receptors desensitize within 100 ms of channel activation, yet recovery from desensitization requires several minutes. The molecular basis for this slow rate of recovery is unknown. We designed experiments to test the hypothesis that this slow recovery is attributable to the high affinity (< 1 nm) of desensitized P2X3receptors for agonist. We found that agonist binding to the desensitized state provided a mechanism for potent inhibition of P2X3current. Sustained applications of 0.5 nmATP inhibited >50% of current to repetitive applications of P2X3agonist. Inhibition occurred at 1000-fold lower agonist concentrations than required for channel activation and showed strong use dependence. No inhibition occurred without previous activation and desensitization. Our data are consistent with a model whereby inhibition of P2X3by nanomolar [agonist] occurs by the rebinding of agonist to desensitized channels before recovery from desensitization. For several ATP analogs, the concentration required to inhibit P2X3current inversely correlated with the rate of recovery from desensitization. This indicates that the affinity of the desensitized state and recovery rate primarily depend on the rate of agonist unbinding. Consistent with this hypothesis, unbinding of [32P]ATP from desensitized P2X3receptors mirrored the rate of recovery from desensitization. As expected, disruption of agonist binding by site-directed mutagenesis increased the IC50for inhibition and increased the rate of recovery.
Brown Bullhead as an Indicator Species: Seasonal Movement Patterns and Home Ranges within the Anacostia River, Washington, D.C.
Authors: Sakaris Peter C. , Jesien Roman V. , Pinkney Alfred E.
Published: August 2005

Elevated liver and skin tumor prevalence has been reported in brown bullhead Ameiurus nebulosus from the tidal Anacostia River, Washington, D.C. Movement data are needed to effectively use tumor prevalence as an indicator of habitat quality. We used ultrasonic telemetry to verify the residency of 40 adult brown bullheads (250–310 mm total length) in the Anacostia River during summer 2000, spring 2001, and fall–winter 2001–2002. During summer (10 fish tagged), fish remained within 500 m of their capture–release location, and their mean 95% minimum area polygon (MAP) and linear home ranges were 4.5 ha and 0.50 km. During spring (12 fish tagged), most fish traveled upstream of the capture–release location as water temperatures increased; they were approximately 1 km upriver by the end of the season. Mean 95% MAP and linear home ranges in spring were 19.7 ha and 2.1 km. During fall–winter (18 fish tagged), fish released in the river remained within 4.2 km upstream and 3.1 km downstream of their capture– release location, and their mean 95% MAP and linear home ranges were 15.9 ha and 2.1 km. In comparison, the 95% MAP and linear home ranges of fish released in Lake Kingman (a tidal freshwater impoundment of the Anacostia) were 5.8 ha and 0.58 km. No fish were located outside of the Anacostia River. We conclude that adult brown bullheads were resident in the system throughout the year.
Recolonization by Warmwater Fishes and Crayfishes after Severe Drought in Upper Coastal Plain Hill Streams
Authors: Adams Susan B. , Warren Melvin L.
Published: August 2005

Extreme hydrologic disturbance, such as a supraseasonal drought, can dramatically influence aquatic communities. Documentation of the responses of aquatic communities after such disturbances provides insight into the timing, order, and mechanisms of recolonization. Postdisturbance recolonization of streams depends on many factors, including the region and characteristics of the disturbance relative to the disturbance regime. A supraseasonal drought that ended in the fall of 2000 resulted in the desiccation of numerous small streams or stream segments in northern Mississippi that were normally perennial. We repeatedly sampled fish and crayfish during predrought and postdrought periods in seven stream reaches that dried and five that remained flowing during the drought. From immediately after the drought until early summer of 2001, postdrought fish and crayfish assemblages differed from predrought assemblages in dry sites but not in flowing sites. The initially slow recolonization rates increased considerably during early spring 2001 so that by June 2001 fish catch per unit effort, species composition, and species richness in dry sites no longer differed significantly from predrought values. The fish recolonization process was highly ordered, as indicated by significant patterns of species nestedness over time in dry sites. Crayfish numerical recovery followed a pattern similar to that for fish, and we captured more crayfish in June 2001 than in the predrought period. Patterns in fish and crayfish population size structures over time indicated that repopulation was due to both immigration and reproduction. Recolonization was indicative of high mobility, particularly during spring and early summer. Although the fauna was quite resilient to stream desiccation, the effects on fish species composition and fish and crayfish size structure persisted 1 year after the drought.
Close Encounters with a Fish Screen: Integrating Physiological and Behavioral Results to Protect Endangered Species in Exploited Ecosystems
Authors: Swanson Christina , Young Paciencia S. , Cech Joseph J.
Published: August 2005

Protection of endangered species that are restricted to highly modified ecosystems and threatened by anthropogenic activities often includes regulatory design and operational criteria for structures and facilities located within the species' critical habitat. In many freshwater systems, loss of fishes at water diversions has contributed to population declines of multiple species. Fish screens prevent removal of fish from the habitat; however, under current design criteria, the degree of protection provided by screens is unknown for most affected species. We used a large laboratory‐based flume to observe and quantify the responses of delta smelt Hypomesus transpacificus, an endangered osmerid threatened by water diversions in California's Sacramento–San Joaquin Estuary, to a simulated fish screen. For a range of flow and environmental conditions, we measured screen contact frequency, swimming behavior, injuries, and survival. Delta smelt experienced frequent temporary contact with the screen, and contact rates were influenced by flow and time of day–light level. Contact was injurious, and postexperiment mortality rates were directly related to both contact frequency and severity as well as temperature. Quantitative models showed that, for this species, both behavioral responses such as swimming velocity and physiological responses to fish screen contact, as modified by environmental conditions, controlled the species' performance and its risk from the diversion and the screen. The results illustrate that ecologically effective protection strategies and regulatory criteria developed on the basis of multiple integrated responses of the organism to the stressor offer greater benefits and certainty to both the organism and the regulated activities.
Simple and Efficient Isolation of Hematopoietic Stem Cells from H2K-zFP Transgenic Mice
Authors: Surdez Didier , Kunz Beatrice , Wagers Amy J. , Weissman Irving L. , Terskikh Alexey V.
Published: August 2005

We have generated a transgenic mouse line that allows for simple and highly efficient enrichment for mouse hematopoietic stem cells (HSCs). The transgene expresses a green fluorescent protein variant (zFP) under the control of H2Kb promoter/enhancer element. Despite the broad zFP expression, transgenic HSCs express exceptionally high levels of zFP, allowing prospective isolation of a population highly enriched in HSCs by sorting the 0.2% of the brightest green cells from the enriched bone marrow of H2K-zFP mice. Up to 90% of zFPbright cells are also c-kithigh, Sca-1high, Linneg, Flk-2neg, which is a bona fide phenotype for long-term HSCs. Double-sorted zFPbright HSCs were capable of long-term multilineage reconstitution at a limiting dilution dose of approximately 12 cells, which is comparable to that of highly purified HSCs obtained by conventional multicolor flow cytometry. Thus, the H2K-zFP transgenic mice provide a straightforward and easy setup for the simple and highly efficient enrichment for genetically labeled HSCs without using fluorescence-conjugated monoclonal antibodies. This approach will greatly facilitate gene transfer, including short interfering RNA for gene knockdown, into HSCs and, consequently, into all other hematopoietic lineages.
Metals Distribution and Interactions in Tissues of Shrews (Sorexspp.) from Copper‐ and Zinc‐Contaminated Areas in Poland
Authors: Świergosz‐Kowalewska R. , Gramatyka M. , Reczyński W.
Published: August 2005

To assess the risk from heavy metal accumulation to insectivorous species exposed to different pollutants, shrews [Sorex araneus(Linnaeus 1758) andSorex minutus(Linnaeus 1766)] were collected in the Olkuski Ore Region (OOR; a Zn and Cd smelter area), Legnicko–Głogowski Copper Mine Region (LGCR; a copper ore‐mining area), and Białowieża Forest (BF; a control area). A few sites were chosen in each region and a total of 57 animals were collected from them. The liver and kidneys were dissected from the animals, dried, and digested in a 4:1 mixture of HNO3(nitric acid) and HClO4(perchloric acid). Cadmium, lead, zinc, copper, and iron were determined in the samples by flame or flameless atomic absorption spectrometry. The interactions between toxic and essential metals were calculated for each tissue. The data showed that accumulation of metals by insectivores is high; shrews accumulated much higher amounts of cadmium and lead than bank voles, studied by other researchers, from the same areas. The expected high tissue accumulation of copper at LGCR and zinc at OOR was not seen, but the levels of both elements were higher in the tissues of shrews from OOR than from LGCR. The lowest copper concentrations were in the tissues of shrews from BF. The highest cadmium and lead concentrations were found in the tissues of shrews from OOR. Some significant correlations were found between the tissue concentrations of xenobiotic and essential metals (e.g., between cadmium and zinc and between lead and iron).
The Effect of Flow Path and Mixing Layer on Phosphorus Release
Authors: Sánchez M. , Boll J.
Published: August 2005

Soil phosphorus (P) concentrations typically are greater in surface soils compared with subsurface soils. Surface soils have a greater chance to interact with runoff leading to P transport to streams. The thin surface layer where P concentrates is referred to as the mixing layer denoting where water and chemicals mix during transport. The objective of this study was to evaluate the effect of hydrologic flow paths on soluble reactive phosphorus (SRP) loss at two temperatures. Laboratory flumes were built to simulate infiltration, return flow, saturation excess, and interflow, and subsequent interaction with the mixing layer. The sandy loam soil in the flumes was kept at saturation throughout all experiments, so that biochemical effects were normalized. Flow through the flumes was maintained at 3.6 mm/h for 24 to 99 h (at 6 and 25°C) with water entering and exiting the flumes at different ports (to simulate different flow paths) or as low intensity rainfall. Experiments were performed with and without an artificially created P‐enriched surface layer (5 mm thick, total P increased from 1010 mg/kg in the original soil to 2310 mg/kg by addition of dissolved phosphate). Results indicated that (i) SRP release was greater in soil with a mixing layer than in soil without a mixing layer; (ii) SRP release was greater during experiments at 25°C than at 6°C; (iii) at 25°C, SRP release was greatest when water traversed the mixing layer in the upward direction (i.e., in return flow), and by flow parallel to the mixing layer (i.e., surface runoff); and (iv) at 6°C, SRP release in subsurface flow following rainfall was slightly greater than in return flow and infiltration. Our results confirmed the presence of a variable, temperature‐dependent desorption process when runoff water interacted with the mixing layer. Our findings have important implications for how different water flow paths in and over the soil interact with P in the soil, and what the ultimate concentration will be in runoff and interflow.
Degradation of Potassium Formate in the Unsaturated Zone of a Sandy Aquifer
Authors: Hellstén Pasi P. , Kivimäki Anna‐Liisa , Miettinen Ilkka T. , Mäkinen Risto P. , Salminen Jani M. , Nystén Taina H.
Published: August 2005

This paper presents results from a lysimeter experiment on the fate of potassium formate, an alternative deicing agent. The experiment was performed through the winter and spring to identify any thermal sensitivity in the transport and biodegradation of formate in the lysimeter. Ninety‐eight percent of the total quantity of formate applied was degraded while percolating through the 1.7‐m‐thick unsaturated sand layer within the lysimeter. Concomitantly, the bicarbonate concentration of the percolating water increased. The low concentrations of nitrogen (0.02 mg L−1) and phosphorous (<0.002 mg L−1) in the percolated water, however, potentially limited microbial activity. During the study period, 99% of the applied potassium was retained in the lysimeter, and the ion exchange between the potassium and a variety of monovalent and divalent ions was assumed to be responsible for the leaching of barium, calcium, magnesium, and sodium from the soil material. Except for manganese, the concentrations of the studied metals in the percolated water did not exceed the threshold values set for drinking water by the Council of the European Union. By contrast, the application of potassium formate had a detrimental effect on the vegetation on the lysimeter. To conclude, formate was effectively degraded in the sandy lysimeter and its application did not cause major undesirable changes in the quality of the percolating water. Further research at field scale is, however, needed for instance on the biodegradation of potassium formate and on its impacts on roadside vegetation.
Environmental Implications of Adopting a Dominant Factor Approach to Salinity Management
Authors: Shani Uri , Ben‐Gal Alon , Dudley Lynn M.
Published: August 2005

Additive or multiplicative models of crop response on which salinity management theory have been developed may lead to an erroneous perception regarding compensative interaction among salinity and other growth factors. We present results from studies of biomass production and transpiration of corn (Zea mays L. cv. Jubilee), melon (Cucumis melo L. subsp. melo cv. Galia), tomato (Lycopersicon esculentum Mill. cv. 5656), onion (Allium cepa L. cv. HA 944), and date palms (Phoenix dactylifera L. cv. Medjool) under salinity combined with water or nitrate (growth promoters) or with boron (growth inhibitor). The measured crop responses were to the more severe stress rather than to combinations of the individual effects of the various stresses. Consequences of shifting management of saline water to a dominant factor approach include reduction of environmental contamination and conservation of water resources.
Degradation of Methyl Isothiocyanate and Chloropicrin in Forest Nursery Soils
Authors: Zhang Y. , Spokas K. , Wang D.
Published: August 2005

Recent studies have observed enhanced degradation of methyl isothiocyanate (MITC) from repeated fumigation in agricultural soils. Little is known about fumigant degradation in forest and nursery soils. This study was conducted to determine degradation rates of MITC and chloropicrin (CP) in two forest soils and the impacts of nursery management on degradation of MITC and CP. The half‐life values of MITC and CP were evaluated in the laboratory under isothermal conditions (22 ± 2°C). Three rates representing 0.5×, 1×, and 2× field application rates for each fumigant were used in laboratory incubations. Effect of microbial degradation was determined by conducting incubations with both fresh and sterilized soils. Soil moisture effects were also studied. There was no difference in MITC or CP degradation between fumigated and nonfumigated forest nursery soils. Soil sterilization and high soil moisture content (15% by wt.) reduced MITC and CP degradation. The degradation rates of MITC and CP varied with factors such as nursery history, fumigant application rates, and freshness of tested soils.
Cadmium Solubility and Sorption in a Long‐Term Sludge‐Amended Arable Soil
Authors: Bergkvist Petra , Berggren Dan , Jarvis Nicholas
Published: August 2005

Cadmium solubility and sorption in an arable clay loam soil that had received sewage sludge for 41 years were compared to an unsludged control in batch studies. Soil pH dominated Cd sorption, explaining >92% of the variation in Kd values in both treatments. At any pH, Cd sorption was apparently slightly but significantly (p < 0.05) smaller in the sludge‐amended soil compared to the control, even though the organic carbon content was 70% larger and the ammonium oxalate–extractable iron content was roughly doubled. Correction for dissolved organic carbon (DOC) complexation with the speciation model WHAM reduced the difference in sorption between treatments, but the sludged soil still had significantly smaller Kd values (p < 0.01). Batch equilibrations without addition of Cd showed that there was no significant difference in the solubility of “native” cadmium (defined as EDTA‐extractable Cd) in sludged and control soils. The reason for the lack of increase in Cd sorption in the sludge‐amended soil has not been established, but it may be due to competition for sorption sites on humic compounds with sludge‐derived Fe and trace metals such as zinc. The fact that the pyrophosphate‐extractable (i.e., organically associated) iron content was seven times larger in the sludged soil provides some supporting evidence for this hypothesis.
Corn Residue Level and Manure Application Timing Effects on Phosphorus Losses in Runoff
Authors: Grande Joseph D. , Karthikeyan K. G. , Miller Paul S. , Powell J. Mark
Published: August 2005

Growing interest in corn (Zea mays L.) silage utilization on Wisconsin dairy farms may have implications for nutrient losses from agricultural lands. Increasing the silage cutting height will increase residue cover and could reduce off‐site migration of sediments and associated constituents compared with conventional silage harvesting. We examined the effects of residue level and manure application timing on phosphorus (P) losses in runoff from no‐till corn. Treatments included conventional corn grain (G) and silage (SL; 10‐ to 15‐cm cutting height) and nonconventional, high‐cut (60–65 cm) silage (SH) subjected to different manure application regimes: no manure (N) or surface application in fall (F) or spring (S). Simulated rainfall (76 mm h−1; 1 h) was applied in spring and fall for two years (2002–2003), runoff from 2.0‐ × 1.5‐m plots was collected, and subsamples were analyzed for dissolved reactive phosphorus (DRP), total phosphorus (TP), and P mass distribution in four particle size classes. Total P and DRP loads were inversely related to percent residue cover, but both TP and DRP concentrations were unaffected by residue level. Manure application increased DRP concentrations in spring runoff by two to five times but did not significantly affect DRP loads, since higher concentrations were offset by lower runoff volumes. Spring manure application reduced TP loads in spring runoff by 77 to 90% compared with plots receiving no manure, with the extent of reductions being greatest at the lower residue levels (<24%). The TP concentration in sediments increased as particle size decreased. Manure application increased the TP concentration of the 0‐ to 2‐μm fraction by 79 to 125%, but elevated the 2‐ to 10‐ and 10‐ to 50‐μm fractions to a lesser extent. Recent manure additions were most influential in enriching transported sediments with P. By itself, higher residue cover achieved by high‐cutting silage was often insufficient to lower P losses; however, the combination of manure application and higher residue levels significantly reduced P losses from corn fields harvested for silage.
Fire and Grazing Effects on Wind Erosion, Soil Water Content, and Soil Temperature
Authors: Vermeire Lance T. , Wester David B. , Mitchell Robert B. , Fuhlendorf Samuel D.
Published: August 2005

Selective grazing of burned patches can be intense if animal distribution is not controlled and may compound the independent effects of fire and grazing on soil characteristics. Our objectives were to quantify the effects of patch burning and grazing on wind erosion, soil water content, and soil temperature in sand sagebrush (Artemisia filifolia Torr.) mixed prairie. We selected 24, 4‐ha plots near Woodward, OK. Four plots were burned during autumn (mid‐November) and four during spring (mid‐April), and four served as nonburned controls for each of two years. Cattle were given unrestricted access (April–September) to burned patches (<2% of pastures) and utilization was about 78%. Wind erosion, soil water content, and soil temperature were measured monthly. Wind erosion varied by burn, year, and sampling height. Wind erosion was about 2 to 48 times greater on autumn‐burned plots than nonburned plots during the dormant period (December–April). Growing‐season (April–August) erosion was greatest during spring. Erosion of spring‐burned sites was double that of nonburned sites both years. Growing‐season erosion from autumn‐burned sites was similar to nonburned sites except for one year with a dry April–May. Soil water content was unaffected by patch burn treatments. Soils of burned plots were 1 to 3°C warmer than those of nonburned plots, based on mid‐day measurements. Lower water holding and deep percolation capacity of sandy soils probably moderated effects on soil water content and soil temperature. Despite poor growing conditions following fire and heavy selective grazing of burned patches, no blowouts or drifts were observed.
Functional disomies of the X chromosome influence the cell selection and hence the X inactivation pattern in females with balanced X‐autosome translocations: A review of 122 cases
Authors: Schmidt Malgorzata , Du Sart Desirée
Published: August 2005

We reviewed 122 cases of balanced X‐autosome translocations in females, with respect to the X inactivation pattern, the position of the X break point and the resulting phenotype.

In 77% of the patients the translocated X chromosome was early replicating in all cells analysed. The break points in these cases were distributed all along the X chromosome. Most of these patients were either phenotypically normal or had gonadal dysgenesis, some had single gene disorders, and less than 9% had multiple congenital anomalies and/or mental retardation.

In the remaining 23% of the cases the translocated X chromosome was late replicating in a proportion of cells. In these cells only one of the translocation products was reported to replicate late, while the remaining portion of the X chromosome showed the same replication pattern as the homologous part of the active, structurally normal X chromosome. The analysis of DNA methylation in one of these cases confirmed noninactivation of the translocated segment. Consequently, these cells were functionally disomic for a part of the X chromosome. The presence of disomic cells was highly prevalent in translocations with break points at Xp22 and Xq28, even though spreading of X inactivation onto the adjacent autosomal segment was noted in most of these cases. This suggests that selection against cells with a late replicating translocated X is driven predominantly by a functional disomy X, and that the efficiency of this process depends primarily on the position of the X break point, and hence the size of the noninactivated region. Since the persistence of cells with a late replicating translocated X was usually associated with mental retardation and other abnormalities, it is concluded that the outcome of the selection process against the functional disomy X is the major determinant of the clinical status in most patients with balanced X‐autosome translocations.