bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Dietary Lipid and Fatty Acids on White Bass Reproductive Performance, Egg Hatchability, and Overall Quality of Progeny
Authors: Lane Ryan L , Kohler Christopher C 
Published: March 2006

Abstract
We evaluated the dietary effects of graded levels of highly unsaturated fatty acids (HUFAs) fed to broodstock female white bass Morone chrysops on reproductive performance, egg hatchability, and larval survival of sunshine bass (female white bass × male striped bass M. saxatilis) through the endogenous feeding stage. Dietary treatments consisted of four isocaloric, isonitrogenous diets formulated to contain 45% crude protein and 15% lipid with graded levels of menhaden oil (0, 25, 75, and 100%) or corn oil as the dietary lipid variable. Significant differences existed among the dietary groups in egg fatty acids, which reflected levels in the maternal diet, especially for the neutral lipid component. Similar trends were also found in fatty acids of the polar lipid component and conservation of HUFAs; significantly higher quantities of linoleic acid (18:2[n-6]) were associated with increasing dietary inclusion of corn oil. Eggs with higher hatchability were associated with higher levels of n-3 HUFAs, including eicosapentaenoic acid (20:5[n-3]), docosapentaenoic acid (22:5[n-3]), and docosahexaenoic acid (22:6[n-3]). Our results suggest that white bass broodstock females possess low and moderate regulatory control of fatty acid deposition to the egg within the neutral and polar components, respectively. These results indicate that little to no elongation or desaturation of dietary fatty acids occurs during egg development. Accordingly, the inclusion of elevated levels of dietary HUFAs for white bass broodstock appears to be warranted.
Use of Survey Data to Estimate Economic Value and Regional Economic Effects of Fishery Improvements
Authors: Loomis John 
Published: March 2006

Abstract
This paper demonstrates a straightforward, survey-based approach that allows fisheries economists and managers to go beyond acquiring just a snapshot of current economic value and regional economic effects to estimate how angler use, benefits, and regional effects (e.g., tourism jobs) would increase with increases in the number or size of fish caught. This is performed by linking responses from intended visitation questions to contingent valuation and input–output models. In a case study of the Snake River in Idaho and Wyoming, I determined that for a 100% increase in angler catch, angler use would increase by 64.5% and would create a corresponding increase in annual economic value and jobs. A similar relationship was found for increases in the size of fish caught.
Chinese Attitudes toward Cleft Lip and Palate: Effects of Personal Contact
Authors: Chan R. K. K. , McPherson B. , Whitehill T. L. 
Published: March 2006

Objective: The purpose of this study was to investigate the effect of personal contact on the attitudes of individuals towards persons with cleft lip and palate (CLP) and the possible cultural differences in these attitudes for Chinese respondents living in Hong Kong. Design: Chinese parent, teacher, and employer groups were administered a cleft lip and palate attitudinal questionnaire and the Scale of Attitudes Toward Disabled Persons inventory. Subjects: Thirty-nine parents of children with CLP, 27 teachers of children with CLP, and 37 employers with no previous contact with individuals with CLP participated in the study. Results: The results showed significant intergroup differences on several items involving beliefs concerning emotional health, social development, and employment-related barriers for individuals with CLP, and whether such individuals should seek nonmedical help to treat speech problems. Employers showed a comparatively less favorable attitude to persons with CLP than the two other groups. Conclusion: Parent, teacher, and employer groups in the Chinese community studied showed differences in their attitudes towards individuals with CLP. The findings suggest the need for further community health education to help develop more positive attitudes towards disabled persons in general, as well as programs targeted at reducing negative stereotyping of adults and children with CLP.
Reduction of perchlorate in river sediment
Authors: Simon Rupert , Weber Eric J. 
Published: March 2006

AbstractThe transformation of perchlorate was investigated in river sediment during laboratory batch and column studies to determine if reduction of perchlorate is a viable pathway in natural sediment without previous exposure to perchlorate. Perchlorate at an initial concentration of 10 μM was reduced quantitatively to chloride in 3 d after a lag phase of 2 d in sediment slurries amended with lactate. Raising the initial concentration of perchlorate to 1,000 μM increased the lag phase to 20 d before reduction occurred. At perchlorate concentrations greater than 1,000 μM, the reduction of perchlorate was not observed within 40 d. We speculate that the high concentration of perchlorate specifically was problematic to the microbes mediating the reduction of perchlorate. High levels of nitrate inhibited the reduction of perchlorate as well. In sediment slurries amended with 870 μM sodium nitrate, the reduction of perchlorate at an initial concentration of 100 μM did not occur before day 15 of the experiment, but complete removal of nitrate had occurred by day four. Sediment column studies further demonstrated the dependence of perchlorate reduction on endogenous nitrate levels.
Trophic transfer and biotransformation of polychlorinated biphenyls in zebra mussel, round goby, and smallmouth bass in Lake Erie, USA
Authors: Kwon Tae-Dong , Fisher Susan W. , Kim Gene Wook , Hwang Haejo , Kim Jang-Eok 
Published: March 2006

AbstractTrophic transfer of polychlorinated biphenyl (PCB) congeners in zebra mussels (Dreissena polymorpha), round gobies (Neogobius melanstomus), and smallmouth bass (Micropterus dolomieu) were assessed in four sites along the south shore of the west and central basin of Lake Erie (all sites were in OH, USA). Total PCB levels in smallmouth bass (1,091–1,520 ng/g wet weight) and round gobies (118–256 ng/g wet weight) were similar among sites despite a west-to-east decrease in total PCB concentrations in zebra mussels (29–97 ng/g wet weight). At all sites, PCB body burden increased three- to fivefold at each successive trophic level, suggesting biomagnification in this nonnative food chain. Whereas fish species were dominated by the hexachlorine homologue, zebra mussels were dominated by penta- and hexachlorine homologues; the average degree of chlorination of PCBs was 56.1% for zebra mussels, 60.4% for round goby, and 59.9% for smallmouth bass bodies. Predictive structure-activity relationships based on chemical characteristics, such as the octanol-water partition coefficient (log Kow), had little predictive power on bioaccumulation and biotransformation of PCB congeners because of nonlinearity, threshold relationships, and species-specific differences. Calculated trophic transfer for the smallmouth bass-round goby linkage was higher than for the round goby-zebra mussel linkage. Only when PCB congeners were grouped by chemical structure first (vicinal [adjacent] H-atom position in the phenyl ring) were linear relationships achieved. It appeared that the chemical group to which each congener belonged influenced biotransformation more than species-specific (round gobies vs smallmouth bass) differences. Biotic changes at midtrophic levels, such as exotic species invasions, may have an increasingly important role in determining pollutant cycling and hence pollutant residues in top predators.
Congener-specific toxicokinetics of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and coplanar polychlorinated biphenyls in black-eared kites (Milvus migrans): Cytochrome P4501A—dependent hepatic sequestration
Authors: Kubota Akira , Iwata Hisato , Tanabe Shinsuke , Yoneda Kumiko , Tobata Sachiko 
Published: March 2006

AbstractConcentrations of dioxins and related compounds (DRCs), such as polychlorinated dibenzo- p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (Co-PCBs), were determined in black-eared kites (BEKs; Milvus migrans) collected from the Kanto district in Japan. Total 2,3,7,8-tetra-CDD toxic equivalents (TEQs) were in the range of 99 to 3,800 pg/g lipid weight in the liver and 42 to 760 pg/g lipid weight in the pectoral muscle. Three congeners, including PCB 126, 2,3,4,7,8-penta-CDF, and 1,2,3,7,8-penta-CDD, made a greater contribution to total TEQs in both tissues. Levels of ethoxy-resorufin-O-deethylase activity and a cross-reactive protein with anti-rat cytochrome P4501A (CYP1A) polyclonal antibodies showed no significant correlation with hepatic TEQs. This may be attributed to low sensitivity and insufficient TEQ levels to cause CYP1A induction, high metabolic potential of a series of congeners, and influence of CYP1A inducers other than DRCs. Most of the PCDD/Fs and non-ortho Co-PCBs exhibited a total TEQ- and CYP1A-dependent increase in the liver to muscle concentration ratios, implying their concentration-dependent hepatic sequestration in which CYP1A was involved. Comparison of the toxicokinetics in avian species revealed that BEKs possibly have higher potentials than common cormorants for metabolizing and sequestering certain congeners in the liver in terms of hepatic concentration profiles and liver:muscle concentration ratios, respectively. These results clearly indicate that the toxicokinetics of DRCs is congener-, tissue-, and species-specific as well as concentration-dependent. Therefore, CYP1A expression is one of the critical factors that determine the toxicokinetics in wild avian species.
Influence of metal exposure history on the bioaccumulation and subcellular distribution of aqueous cadmium in the insect Hydropsyche californica
Authors: Cain Daniel J. , Buchwalter David B. , Luoma Samuel N. 
Published: March 2006

Abstract
The influence of metal exposure history on rates of aqueous Cd accumulation, elimination, and subcellular distribution was examined in the aquatic insect Hydropsyche californica. Specimens were obtained from a reference site and a metal-contaminated site and returned to the laboratory where they were continuously exposed to aqueous Cd (518 ng/L, nominal) for 6 d, followed by 9 d of depuration. Rates of Cd accumulation and elimination were similar in insects from the two sites. Efflux rate constants, ke, ranged from 0.20 to 0.24/d (t1/2 ≈ 3 d). Immediately following exposure, the cytosol accounted for 40% of the body burden in insects from both sites; however, 89 ± 2% of the cytosolic Cd was associated with metallothionein-like proteins (MTLP) in insects from the contaminated site, compared to 60 ± 0% in insects from the reference site. The concentration of Cd bound to non-MTLPs (representing potentially Cd-sensitive proteins) was significantly greater in the insects from the reference site (134 ± 7 ng/g) than in those from the contaminated site (42 ± 2 ng/g). At the end of the depuration period, 90% of the accumulated Cd body burden had been eliminated, and Cd concentrations in MTLPs and non-MTLPs were similar between the sites. Results suggested that differences in exposure history had no influence on the bioaccumulation of Cd, but did affect the concentrations of Cd bound to MTLP during Cd exposure in these insects.
Bioaccumulation and trophic transfer of polychlorinated biphenyls by aquatic and terrestrial insects to tree swallows (Tachycineta bicolor)
Authors: Maul Jonathan D. , Belden Jason B. , Schwab Becky A. , Whiles Matt R. , Spears Brian , Farris Jerry L. , Lydy Michael J. 
Published: March 2006

AbstractInsectivorous passerines often bioaccumulate polychlorinated biphenyls (PCBs) via trophic transfer processes. Tree swallows (Tachycineta bicolor) frequently are used for estimating PCB bioaccumulation, yet the focus on specific trophic links between contaminated sediment and bird has been limited. Bioaccumulation of PCBs from sediment to tree swallows was examined with focus on trophic pathways by simultaneously examining PCBs in emergent aquatic and terrestrial insects and gut contents of nestlings. Total PCB concentrations increased from sediment (123.65 ± 15.93 μg/kg) to tree swallow nestlings (2,827.76 ± 505.67 μg/kg), with emergent aquatic insects, terrestrial insects, and gut content samples having intermediate concentrations. Biota-sediment accumulation factors (BSAFs) varied among congeners for tree swallow nestlings and for male and female Chironomus spp. For nestlings, the highest BSAF was for the mono-ortho-substituted congener 118. Nestling biomagnification values were similar for gut contents and female Chironomus spp., suggesting this diet item may be the main contributor to the overall PCB transfer to nestlings. However, gut content samples were highly variable and, on a PCB congener pattern basis, may have been influenced by other taxa, such as terrestrial insects. Considering dietary plasticity of many insectivorous birds, the present study suggests that a variety of potential food items should be considered when examining PCB accumulation in insectivorous passerines.
A molecular modeling analysis of polycyclic aromatic hydrocarbon biodegradation by naphthalene dioxygenase
Authors: Wammer Kristine H. , Peters Catherine A. 
Published: March 2006

Abstract
A theoretical analysis was performed to examine the role of naphthalene dioxygenase(NDO) enzymes in determining differences in biodegradability and biodegradation rates of two- to four-ring polycyclic aromatic hydrocarbons (PAHs) via oxygenation and desaturation reactions. Investigation of the thermodynamics of PAH biodegradation reactions catalyzed by NDO revealed that enthalpies of reaction can explain reaction patterns or regioselectivity of the enzyme in limited cases. Molecular modeling analysis of the size and shape constraints of PAH-enzyme interactions suggests that PAHs bigger than approximately four rings and compounds with α substituents or other structural features contributing to increased width at the end of the substrate near the active site are expected to have binding difficulties. This explains some regioselectivity observations, in that thermody-namically favorable sites on some PAH molecules cannot be positioned correctly to be oxidized at the active site. The enzyme fit analysis also suggests that slower biodegradation rates are expected for compounds with larger widths because of the unique positioning that is required for reaction to occur. An inverse relationship between a molecular descriptor of compound width and previously obtained biodegradation rates suggests that this descriptor may be valuable for predicting relative biodegradation rates of PAHs with dioxygenases other than NDO.
EFFECTS OF dl‐AMPHETAMINE UNDER CONCURRENT VI DRL REINFORCEMENT
Authors: Segal Evalyn F. 
Published: March 2006

Three adult, food‐deprived rats were given IP injections of dl‐amphetamine sulfate under DRL and concurrent VI DRL reinforcement schedules. The drug results were as follows.
The IRT distributions of DRL responses shifted to the left, but some temporal discrimination remained.
The IRT distributions of VI responses shifted slightly to the left.
The distinguishing characteristics of VI and DRL IRT distributions were preserved.
The frequency distribution of number of VI responses between two consecutive DRL responses was relatively unaffected. (5) Over‐all response rates on the two components of the concurrent schedules increased more or less proportionately.
These findings imply that the primary behavioral effect of dl‐amphetamine was a motor excitatory one. The drug's disruption of timing behavior was not due to a derangement of internal timing mechanisms, nor to interference with the topography or pattern of behavior. Rather, it might be a secondary result of the accelerated emission of overt behavior patterns mediating the temporal spacing of DRL bar presses.
AN ADJUSTING AVOIDANCE SCHEDULE1
Authors: Sidman Murray 
Published: March 2006

A shock‐avoidance schedule is described in which the animal accumulated 5 sec of safe time whenever it pressed a lever. With this schedule, the animal was not differentially reinforced for long pauses between responses; and, consistent with this property of the schedule, the probability that the animal would press the lever was not related in any regular way to the amount of time that had elapsed since its preceding lever press. Other features of the performance are also described.If the animal was given a warning stimulus whenever it came within 5 sec of a shock, it tended to spend more time in the close temporal vicinity of the shock and less time at the maximum temporal distance from shock.
A TRACKING PROCEDURE FOR DETERMINING THE CAT'S FREQUENCY DISCRIMINATION1
Authors: Elliott D. N. , Frazier L. , Riach W. 
Published: March 2006

A tracking procedure was used to investigate the time required to train cats to discriminate between a frequency‐modulated tone and a steady tone. The animal was reinforced with food on a VR schedule only when the steady tone was present and the animal pressed the correct bar (one of two). After reinforcement, the steady tone usually changed to a frequency‐modulated signal; by pressing the other bar, the tone could be changed to its steady state and the reinforcement then obtained as before. A major difficulty was the lack of control by the auditory stimulus on the cat's responses. This problem was solved by introducing interpress time outs which forced the animal to hesitate after every press. The use of light cues to signal the time outs and the correct bar to press accelerated the rate at which the training progressed.With cats, this conditioning procedure apparently requires a much longer training period before the actual threshold determinations than the more commonly used avoidance conditioning procedures. However, when animals are to be tested repeatedly over a period of several months or longer, the procedure may prove the more desirable one because it reduces experimental neurosis.
CONTROL OF THE BEHAVIOR OF SCHIZOPHRENIC PATIENTS BY FOOD1
Authors: Ayllon T. , Haughton E. 
Published: March 2006

Operant‐conditioning principles using food as a reinforcer were applied to control the behavior of 45 chronic schizophrenic patients. The investigation was conducted in a psychiatric ward in which there was 24‐hr environmental control.In order to use food as a reinforcer for controlling psychotic behavior, it was necessary first to deal with the eating deficits in the patients. Approximately 50% of the ward population was selected because of a history of refusal to eat. Their refusal to eat had remained relatively unaffected by one or more of these treatments: spoonfeeding, tubefeeding, intravaneous feeding, and electroshock. These treatments were discontinued, and the patients were left alone at mealtimes. The results show that social reinforcement in such forms as coaxing, persuading, and feeding the patient tend to shape patients into eating problems so they are conditioned to eat only with assistance. When refusal to eat was no longer followed by social reinforcement, the patients soon started eating unassisted. When access to the dining room was made dependent upon a chain of responses including a motor and social component, all patients learned these responses.
GENERALIZATION GRADIENTS OF INHIBITION FOLLOWING AUDITORY DISCRIMINATION LEARNING1
Authors: Jenkins H. M. , Harrison R. H. 
Published: March 2006

A more direct method than the usual ones for obtaining inhibitory gradients requires that the dimension of the nonreinforced stimulus selected for testing be orthogonal to the dimensions of the reinforced stimulus. In that case, the test points along the inhibitory gradient are equally distant from the reinforced stimulus. An attempt was made to realize this condition by obtaining inhibitory gradients along the frequency dimension of a pure tone after discrimination training in which the nonreinforced stimulus was a pure tone (or tones), and the reinforced stimulus was either white noise or the absence of a tone. The results showed that some degree of specific inhibitory control was exerted by the frequency of the tone, although the gradients were broad and shallow in slope.A further experiment was conducted to see whether the modification of an excitatory gradient resulting from training to discriminate neighboring tones could arise from a simple interaction of inhibitory and excitatory gradients. The results indicated that it could not, since discrimination training produced a concentration of responding in the vicinity of the reinforced stimulus which cannot be derived from any plausible gradient of inhibition.
ADDITIONAL TECHNIQUES FOR PRODUCING MULTIPLE‐SCHEDULE CONTROL IN CHILDREN1,2
Authors: Long Eugene R. 
Published: March 2006

The subjects in these experiments were 132 children, varying in age from 4 to 7 years. These experiments were designed to assess the efficacy of various multiple scheduling procedures in producing reliable stimulus control. The schedules studied were multiple fixed‐ratio—extinction (mult FR EXT); multiple differential‐reinforcement‐of‐other‐behavior—fixed‐ratio (mult DRO FR); multiple differential‐reinforcement‐for‐low‐rate—fixed‐ratio (mult DRL FR); and multiple fixed‐interval—fixed‐ratio (mult FI FR). In addition other techniques were investigated, such as presenting FR's in blocks; increasing the size of the FR's; attaching a DRL to the FI members; temporarily shifting to new schedules; and adding an external clock to the FI's. These experiments yielded the following results.
.) Strong stimulus control was produced by mult FR EXT, mult DRO FR, and mult DRL FR schedules. Control for mult FR EXT was mediated principally by the individual stimuli, though on occasion it was dependent in part on the change of stimuli. The mult DRO FR was found to be highly useful for those children who had very high initial rates or who were generally uncooperative and unmanageable.
.) Contrary to a previous finding, some subjects were brought under stimulus control by means of mult FI FR schedules without the aid of additional procedures. Most, however, were not. Additional techniques found to augment the development of mult FI FR control included: (1) presenting FR's in blocks; (2) increasing the size of the FR's; (3) attaching a DRL to the FI component for a time and later removing it; and (4) shifting to a mult DRL FR, developing control, and then returning to the original mult FI FR.
.) Addition of an external clock to the FI components of the mult FI FR had several effects. Strongest control, including well‐developed acceleratory patterns during the FI's, was developed in those subjects who had first been shifted from a regular mult FI FR to a mult FR EXT, brought under control, and then returned to the mult FI FR with the clock added. The added clock also produced strong control if it was present when the subject was first begun on a mult FI FR schedule. In some cases, the addition of the clock produced control in subjects who had not been controlled previously by the regular mult FI FR, but these were always subjects who had high rates. The addition of the clock first lowered the rate, then produced control.