bluuebunny/crossref_metadata_2025_split huggingface dataset:
Poor Growth of Rainbow Trout Fed New Zealand Mud Snails Potamopyrgus antipodarum
Authors: Vinson Mark R. , Baker Michelle A. 
Published: April 2008

Abstract
The New Zealand mud snail (NZMS) Potamopyrgus antipodarum is rapidly invading North American freshwaters, leading to speculation that native fisheries, especially those involving trout, will be negatively impacted. To assess whether trout would consume NZMSs and could assimilate nutrients from them, we conducted a laboratory 15N tracer study, a laboratory feeding study, and bioenergetics modeling with rainbow trout Oncorhynchus mykiss; we also evaluated 5 years of diet and condition data describing rainbow trout and brown trout Salmo trutta collected from a river colonized by NZMSs. The 15N tracer study showed that rainbow trout consumed and to a lesser extent assimilated NZMSs. Rainbow trout fed 15N-labeled NZMSs had muscle isotopic signatures that were 80% higher than those of fish fed unlabeled NZMSs and 30% lower than those of fish fed 15N-labeled amphipods. The feeding study showed that rainbow trout fed an exclusive and unlimited amount of NZMSs lost 0.14–0.48% of their initial body weight per day. Collection of rainbow trout feces showed that 8.5% of the NZMS shells were empty, and these snails were assumed to have been digested; 53.8% of NZMSs passed through the digestive system alive. Bioenergetics modeling showed that starved rainbow trout would have lost between 0.52% and 0.54% of their initial body weight per day, depending on their initial weight. Based on observed fish weight changes during three trial periods, mean modeled digestibility of NZMSs for rainbow trout fed an unlimited supply of the snails (proportion of maximum consumption = 1.0) was 63, 65, and 27%. Field survey data supported our laboratory experiments: we observed a sharp annual increase in the number of brown and rainbow trout consuming NZMSs between 2001 and 2005 in the Green River, Utah, downstream from Flaming Gorge Dam; moreover, the condition of brown and rainbow trout with NZMSs in their guts was significantly lower than that of fish without NZMSs in their stomachs. Our results confirm that North American trout fisheries face potential negative impacts from NZMS invasion.
Escaping the Surface: The Effect of Capture Depth on Submergence Success of Surface-Released Pacific Rockfish
Authors: Hannah Robert W. , Parker Steven J. , Matteson Keith M. 
Published: April 2008

Abstract
We evaluated the effect of capture depth and fish size on the ability of several Pacific rockfishes Sebastes spp. to resubmerge after hook-and-line capture and surface release. We observed fish as they were released into a bottomless floating enclosure, and we recorded submergence success within a 5-min time limit. Submergence success was greater than 80% for all rockfish captured in depths less than 30 m. Yellowtail rockfish S. flavidus (N = 51) were 100% successful at submerging in less than 49 s at all depths sampled (10–51 m). At capture depths of 40–51 m, submergence success was 89% for quillback rockfish S. maliger (N = 9), 65% for black rockfish S. melanops (N = 46), and 30% for canary rockfish S. pinniger (N = 40). At depths of 30–51 m, submergence success was 32% for blue rockfish S. mystinus (N = 31). The external signs of barotrauma (e.g., exopthalmia, eversion of the esophagus) increased with depth of capture and were least prevalent in yellowtail rockfish and quillback rockfish. The presence of severe esophageal eversion (beyond the buccal cavity) was strongly negatively associated with submergence success for several species (P &lt; 0.01). At 40–51-m capture depths, the frequency of severe esophageal eversion by species was correlated with the frequency of submergence failure (P &lt; 0.05). Logistic regression showed a negative relationship between depth of capture and submergence success for black rockfish (P &lt; 0.001), blue rockfish (P &lt; 0.001), and canary rockfish (P &lt; 0.05). Larger body length negatively influenced submergence success only in blue rockfish (P &lt; 0.05).
Modeling Variation in Mass‐Length Relations and Condition Indices of Lake Trout and Chinook Salmon in Lake Huron: A Hierarchical Bayesian Approach
Authors: He Ji X. , Bence James R. , Johnson James E. , Clapp David F. , Ebener Mark P. 
Published: April 2008

AbstractCommonly used approaches to studying mass‐length relations and condition indices often do not adequately address covariance between mass‐length parameters, usually ignore heterogeneity in individual variance for body mass at a given length, and assume that length distributions of fish samples are similar across regions and years. We used body mass at selected lengths as condition indices based on statistical modeling and a hierarchical Bayesian approach to inferences, and our approach allowed us to avoid using restrictive assumptions. We estimated spatial and annual variation in mass‐length relations, where the process errors in parameters are drawn from a multivariate distribution. We also estimated region‐, year‐, and size‐group‐specific variance for individual variation in mass at given lengths. We applied our approach to study mass‐length relations of lake troutSalvelinus namaycush(1977‐2005) and Chinook salmonOncorhynchus tshawytscha(1983‐2004) in U.S. waters of Lake Huron. We found that small lake trout were able to maintain their condition in response to declines in prey availability, whereas Chinook salmon of the same size could not. Similarly, large Chinook salmon exhibited a greater and more rapid decline in body condition than did lake trout of the same size. We also found that spatial differences in recent temporal trends in condition of large fish altered the ranks of the three lake trout management regions. Ignoring spatial heterogeneity led to a biased overall average mass‐length relation for lake trout. The large temporal variation in mass‐length parameters suggested that it was better not to assume isometric growth for a specific year, even though the overall average exponent for Chinook salmon was nearly 3.0. In our study, conventional application of Fulton's condition factor to a relatively narrow size range was able to capture qualitative long‐term trends but missed some important short‐term changes because of the additional variation of length‐related bias and the limitation of sample sizes.
Wastewater modification processes assessment in a stabilization reservoir
Authors: Mannina G. , Mancini G. , Torregrossa M. , Viviani G. 
Published: April 2008

A semi-empirical mechanistic model able to simulate the dynamics of a stabilization reservoir was developed incorporating both settling of particulate components and chemical/biological processes. Several factors affecting the reservoir effluent quality were taken into account: hydraulics and hydrology, solar radiation, atmospheric reaeration, algae, zooplankton, organic matter, pathogen bacteria, and sediment-water interaction. The model quantifies the specific influence of each factor on effluent quality, evaluating the correlation between the different considered factors. State variables included in the model were: algae, dissolved oxygen, organic matter, zooplankton and indicator bacteria.
The model was transferred into a computational code in order to provide a useful and versatile tool for water resource planning management issues. The model was verified by comparing simulated results with full-scale data collected from a small reservoir (Sicily, IT) filled with partially treated wastewater. The reservoir has a volume of 11,000 m3, a maximum depth of 6.3 m and a mean depth of about 5 m. The monitoring period lasted four months during which the reservoir operated in different hydraulics conditions: as a standard batch reactor and as a continuous flow reactor. The model was able to reproduce the behaviour of the principal simulated parameters thus representing a potential tool for the management and performance optimization of these peculiar storage/treatment systems.
Reactive tracers reveal hydraulic and control instabilities in full-scale activated sludge plant
Authors: Braun D. , Gujer W. 
Published: April 2008

The hydraulic characteristics of aeration tanks in WWTPs have a major impact on the degradation of pollutants, as well as on the control of the aeration. In particular in long reactors, which are not separated by baffles, hydraulic shortcuts or large scale recirculation can lead to a loss of performance. This work demonstrates that reactive tracers such as ammonium and oxygen can be used to investigate the hydraulics of aeration tanks in detail. With the use of electrochemical sensors it is possible to investigate effects in a broad range of time scales.
In the present case study a slow oscillation of the aeration control loop was investigated. Large scale recirculation in the aeration tank and fast fluctuations of the ammonium concentrations close to the oxygen sensor were identified as the cause of these oscillations. Both, the recirculation as well as the fluctuation of the ammonium have a substantial influence on the performance of the aeration tank and the aeration control loop.
Preventing Film Blocking and Optimizing Haze of Metallocene PE Blown Films Through Blending with Rigid Polymers
Authors: Chinsirikul W. , Fuongfuchat A. , Kerddonfag N. , Phiboonkulsumrit S. , Winotapun C. , Khumsang P. 
Published: April 2008

Abstract
Film blocking typically observed in both mPE and higher modulus mPE/PP blends could be effectively reduced or prevented through the incorporation of only 2 wt.-% of rigid PS or PMMA into the blends. Blocking forces required to separate the two adjacent layers of mPE/[PP/PS] and mPE/[PP/PMMA] films were significantly reduced from 20.9 g for the neat mPE, to 0 g and 10.8 g, respectively. Films containing rigid PS, however, possessed high haze of 32.37 % while a much lower haze of 10.88 % was obtained for films with PMMA. Based on atomic force microscopy (AFM) results, total haze increased systematically with an increase in RMS surface roughness. Nevertheless, there seemed to be a critical surface roughness that could give rise to both low film blocking and low optical haze, as found in the mPE/[PP/PMMA] films. All developed films also had suitable mechanical properties and high oxygen transmission rates, OTR (> 10 000 cm3/m2 day); these high OTR films are desirable for fresh produce packaging. Current findings also demonstrate that controlling film morphologies of these mPE blends with PS and PMMA through mixing and processing principles appears to be a promising route in determining surface roughness and internal structure that have direct influences on film blocking and clarity or haze.
Development of Bicomponent Spunbond Nonwoven Webs Consisting of Ultra-fine Splitted Fibers
Authors: Prahsarn C. , Matsubara A. , Motomura S. , Kikutani T. 
Published: April 2008

Abstract
Development of bicomponent spunbond nonwoven consisting of ultra-fine splitted polypropylene (PP) and polyethylene (PE) fibers was described. The morphological structures developed in bicomponent spinning of PP/PE fibers with the cross-sectional configuration of “sixteen-segment hollow pie” were investigated in relation to molecular properties as well as the resulting fiber splittability. Structure developed in each component in the melt spinning process was found to depend not only on its molecular properties but also on those of the other component. Results showed that the PP/PE pair exhibiting good splittability possesses high molecular orientation in both components.
Erosive Wear Assesment of Glass Reinforced Polyester-Flyash Composites Using Taguchi Method
Authors: Patnaik A. , Satapathy A. , Mahapatra S. S. , Dash R. R. 
Published: April 2008

Abstract
Experiments are conducted to study the solid particle erosion wear behavior of glass reinforced polyester composites with flyash as a filler material. This study makes use of a methodology based on Taguchi's experimental design approach to characterize the erosion response of these composites. The procedure eliminates the need for repeated experiments and thus saves time, materials and cost. It identifies not only the significant control factors but also their interactions influencing the erosion rate predominantly. From the experimental findings an optimal combination of control factors is obtained on the basis of a proposed predictive model. This model is validated by performing a confirmation experiment with an arbitrarily chosen set of factor combination. Finally, optimal factor settings for minimum wear rate under specified experimental conditions have been determined using genetic algorithm.
An Experimental Study on the Pickout of Scaled-up Gravure Cells
Authors: Chuang H.-K. , Lee C.-C. , Liu T.-J. 
Published: April 2008

Abstract
An experimental study was carried out to investigate the pickout of scaled-up gravure cells. The pickout of a gravure cell is defined as the fractional volume of the coating solution transferred from the cell to the moving roller. Gravure cells of different sizes and combinations were examined. Dilute poly(vinyl) alcohol solutions was used as test fluids.
It was found that the stability of the liquid bridge that connects the moving roller and the gravure cell is the most critical factor to determine the pickout. The most stable condition that yields the maximum pickout is that the moving roller just touches the gravure cell and the coating gap is zero. Either a positive or a negative coating gap will decrease the pickout.
The pickout for a small gravure cell is lower than a larger one because the liquid bridge is less stable. The experiment on different cell combinations reveals that if the number of gravure cells in the coating direction is increased, the average pickout per cell will drop. The pickout decreases as the capillary number increases. A universal correlation was found between the modified pickout and the capillary number. This modified pickout is the product of the pickout and a shift factor which involves all the geometric parameters in gravure cells.
Spatial scale of GIS‐derived categorical variables affects their ability to separate sites by community composition
Authors: Holt Emily A. , McCune Bruce , Neitlich Peter 
Published: April 2008

Abstract.Questions: How well do GIS‐derived categorical variables (e.g., vegetation, soils, geology, elevation, geography, and physiography) separate plots based on community composition? How does the ability to distinguish plots by community composition vary with spatial scale, specifically number of patch types, patch size and spatial correlation? Both these questions bear on the effective use of stratifying variables in landscape ecology.Location: Arctic tundra; Bering Land Bridge National Preserve, northwestern Alaska, USA.Methods: We evaluated the strength of numerous alternative stratifying variables using the multi‐response permutation procedure (MRPP). We also created groups based on lichen community composition, using cluster analyses, and evaluated the relationship between these groups and groupings within categorical variables using Mantel tests. Each test represents different measures of community separation, which were then evaluated with respect to each variable's spatial characteristics.Results: We found each categorical variable derived from GIS separated lichen communities to some degree. Separation success ranged from strong (Alaska Subsections) to weak (Watersheds and Reindeer Ownership). Lichen community groups derived from cluster analysis demonstrated statistically significant relationships with 13 of the 17 categorical variables. Partialling out effects of spatial distance had little effect on these relationships.Conclusions: Greater number of patch types and larger average patch sizes contribute to optimal success in separating lichen communities; geographic distance did not appear to significantly alter separation success. Group distinctiveness or strength increased with more patch types or groups. Alternatively, congruence between lichen community types derived from cluster analysis and the 17 categorical variables was inversely related to patch size and spatial correlation.
Culture and the socialization of child cardiovascular regulation at school entry in the US
Authors: Decaro Jason A. , Worthman Carol M. 
Published: April 2008

AbstractThe measurement of cardiovascular functioning targets an important bridge between social conditions and differential well‐being. Nevertheless, the biocultural, psychosocial processes that link human ecology to cardiovascular function in children remain inadequately characterized. Childrearing practices shaped by parents' cultural beliefs should moderate children's affective responses to daily experience, and hence their psychophysiology. The present study concerns interactions among family ecology, the normative social challenge of entry into kindergarten, and parasympathetic (vagal) cardiac regulation in US middle‐class children (N= 30). Although parents believed children must be protected from overscheduling to reduce stress and improve socio‐emotional adaptation, maternal rather than child schedules predicted parasympathetic regulation during a nonthreatening social engagement task following school entry. Children of busier married mothers, but less busy single mothers, showed the context‐appropriate pattern of parasympathetic regulation, low respiratory sinus arrhythmia (RSA). These findings are expected if: maternal and family functioning, rather than the scheduling of the child's daily life, principally drive young children's cardiovascular responsiveness to a normative challenge; and busy schedules represent high family functioning with married mothers, but not under single‐parent conditions wherein adult staffing is uniquely constrained. Family ecology is shaped by culture, and in turn shapes the development of children's cardiovascular responses. Appropriately fine‐grained analysis of daily experience can illustrate how culturally driven parenting practices may have unintended consequences for child biological outcomes that vary by family structure. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.
Dendrimer‐encapsulated Pt nanoparticles/polyaniline nanofibers for glucose detection
Authors: Xu Lihuan , Zhu Yihua , Tang Longhua , Yang Xiaoling , Li Chunzhong 
Published: April 2008

AbstractA novel amperometric glucose biosensor based on self‐assembling glucose oxidase (GOx) and dendrimer‐encapsulated Pt nanoparticles (Pt‐DENs) on nanofibrous polyaniline (PANI) was described. PANI nanofibers were synthesized via an interfacial polymerization method. A sulfonated polyelectrolytes‐poly(sodium 4‐styrenesulfonate) (PSS) was used to form the negative PANI/sulfonated polyelectrolyte complex, which had good disperse in aqueous solution. GOx was immobilized on the PANI/PSS surface by alternatively assembling a cationic Pt‐DENs layer and an anionic GOx layer. The unique sandwich‐like layer structure (Pt‐DENs/GOx/Pt‐DENs/PANI/PSS) formed by self‐assembling provides a favorable microenvironment to keep the bioactivity of GOx and to prevent enzyme molecule leakage. The fabricated Pt‐DENs/GOx/Pt‐DENs/PANI/PSS electrode exhibited excellent response performance to glucose with a detection limit of 0.5 μM, wide linear range from 10 μM to 4.5 mM, short response time within 5 s, improved sensitivity of 39.63 μA/(mM cm2), and good stability (85% remains after 20 days). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
3D‐QSAR Studies on Chromone Derivatives as HIV‐1 Protease Inhibitors: Application of Molecular Field Analysis
Authors: Nunthanavanit Patcharawee , Anthony Nahoum G. , Johnston Blair F. , Mackay Simon P. , Ungwitayatorn Jiraporn 
Published: April 2008

AbstractThree‐dimensional quantitative structure‐activity relationship (3D‐QSAR) models were developed for chromone derivatives against HIV‐1 protease using molecular field analysis (MFA) with genetic partial least square algorithms (G/PLS). Three different alignment methods: field fit, pharmacophore‐based, and receptor‐based were used to derive three MFA models. All models produced good predictive ability with high cross‐validated r2(r2cv), conventional r2, and predictive r2(r2pred) values. The receptor‐based MFA showed the best statistical results with r2cv= 0.789, r2= 0.886, and r2pred= 0.995. The result obtained from the receptor‐based model was compared with the docking simulation of the most active compound21in this chromone series to the binding pocket of HIV‐1 protease (PDB entry 1AJX). It was shown that the MFA model related well with the binding structure of the complex and can provide guidelines to design more potent HIV‐1 protease inhibitors.
Functional characterization of hypertrophy in chondrogenesis of human mesenchymal stem cells
Authors: Mueller Michael B. , Tuan Rocky S. 
Published: April 2008

AbstractObjectiveMesenchymal stem cells (MSCs) are promising candidate cells for cartilage tissue engineering. Expression of cartilage hypertrophy markers (e.g., type X collagen) by MSCs undergoing chondrogenesis raises concern for a tissue engineering application for MSCs, because hypertrophy would result in apoptosis and ossification. To analyze the biologic basis of MSC hypertrophy, we examined the response of chondrifying MSCs to culture conditions known to influence chondrocyte hypertrophy, using an array of hypertrophy‐associated markers.MethodsHuman MSC pellet cultures were predifferentiated for 2 weeks in a chondrogenic medium, and hypertrophy was induced by withdrawing transforming growth factor β (TGFβ), reducing the concentration of dexamethasone, and adding thyroid hormone (T3). Cultures were characterized by histologic, immunohistochemical, and biochemical methods, and gene expression was assessed using quantitative reverse transcription–polymerase chain reaction.ResultsThe combination of TGFβ withdrawal, a reduction in the level of dexamethasone, and the addition of T3 was essential for hypertrophy induction. Cytomorphologic changes were accompanied by increased alkaline phosphatase activity, matrix mineralization, and changes in various markers of hypertrophy, including type X collagen, fibroblast growth factor receptors 1–3, parathyroid hormone–related protein receptor, retinoic acid receptor γ, matrix metalloproteinase 13, Indian hedgehog, osteocalcin, and the proapoptotic gene p53. However, hypertrophy was not induced uniformly throughout the pellet culture, and distinct regions of dedifferentiation were observed.ConclusionChondrogenically differentiating MSCs behave in a manner functionally similar to that of growth plate chondrocytes, expressing a very similar hypertrophic phenotype. Under the in vitro culture conditions used here, MSC‐derived chondrocytes underwent a differentiation program analogous to that observed during endochondral embryonic skeletal development, with the potential for terminal differentiation. This culture system is applicable for the screening of hypertrophy‐inhibitory conditions and agents that may be useful to enhance MSC performance in cartilage tissue engineering.