bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of a new generation of plastic evacuated blood-collection tubes in clinical chemistry, therapeutic drug monitoring, hormone and trace metal analysis
Authors: Boeynaems Jean-Marie , Leener Anne De , Dessars Barbara , Villa-Lobos Hector Rodriguez , Aubry Jean-Claude , Cotton Frédéric , Thiry Philippe
Published: August 2004

Polyethylene terephthalate (PET) tubes have several advantages over glass tubes: they are unbreakable, lighter and more easily disposed of. Despite a steady increase in their use and an expansion of the range of available tubes, few studies validating their use have been published in the literature. This paper describes the various studies that have been performed to compare VENOJECT glass, VENOSAFE PET and VENOSAFE PET/heparin tubes for the assay of a panel of analytes in routine clinical chemistry, immunochemistry, hormone and tumor marker analysis and trace metal determination. These studies demonstrate that VENOSAFE PET tubes are a suitable alternative to glass tubes.
Effects of Stress on Largemouth Bass Reproduction
Authors: Ostrand Kenneth G. , Cooke Steven J. , Wahl David H.
Published: August 2004

Although largemouth bass Micropterus salmoides are frequently subjected to sublethal stressors (e.g., angling), the associated effects on their reproductive success have not been assessed. We examined the reproduction of largemouth bass that were subjected to the stress of exhaustive exercise, air exposure, culling, live-well conditions, and weigh-in procedures. Age-0 largemouth bass produced from parents subjected to stress were smaller (total length, 31 ± 0.4 mm (mean ± SE)) and weighed less (0.59 ± 0.04 g) than controls that were not stressed (35 ± 0.4 mm; 0.76 ± 0.03 g). Adults that were stressed had offspring with later swim-up dates than did controls. Our results provide evidence that stress before spawning has the potential to negatively affect largemouth bass reproductive success.
Decline of Yellow Perch in Southwestern Lake Michigan, 1987–1997
Authors: Marsden J. Ellen , Robillard Steven R.
Published: August 2004

The abundance of yellow perch Perca flavescens in southwestern Lake Michigan declined severely in the 1990s, after state and federal agencies noted a lakewide paucity of age-0 yellow perch in 1989. Regulations were changed in 1995 to reduce recreational and commercial fishing harvests, and commercial fisheries were closed lakewide in 1997. To document changes in the yellow perch population and to evaluate possible causes of the decline, we examined data collected annually in the Illinois waters of Lake Michigan during 1987–1997. Larval yellow perch were collected with plankton nets, age-0 yellow perch were collected with bottom trawls, and adult yellow perch were collected with fyke nets and gill nets. Age-0 yellow perch were rare or absent after 1988; however, larval abundance did not decline severely until after 1993. The presence of larvae and the almost complete absence of age-0 yellow perch in 1989–1993 suggest that overfishing was not initially responsible for the decline. The length at age and mean age of adult yellow perch increased steadily during the study period. The percentage of males in our samples increased to 99%. The reduction in larval catches since 1994 and the highly skewed sex ratio indicate that the number of reproducing female yellow perch was reduced below a critical level. The causes for the decline are unclear, but the demographics of the decline suggest that neither commercial fishing nor predation by alewives Alosa pseudoharengus on larvae were responsible, whereas alterations in the Lake Michigan ecosystem subsequent to the invasion by zebra mussels Dreissena polymorpha may have influenced the decline.
The Effects of Catch-and-Release Angling on the Growth and Survival of Juvenile White Seabass Captured on Offset Circle and J-Type Hooks
Authors: Aalbers Scott A. , Stutzer Greg M. , Drawbridge Mark A.
Published: August 2004

Despite the growing number of recreational anglers targeting white seabass Atractoscion nobilis in California, no information is available on the mortality rates of juveniles following catch and release. We captured juvenile white seabass (430–577 mm total length) with 4/0 offset circle hooks (n = 113) or 4/0 J-type hooks (n = 108) or with a net (control, n = 30) to investigate the effect of hook type on anatomical hook location. We also examined how hook location affected growth and survival for 90 d following release. Offset circle hooks penetrated the lip region significantly more frequently (73%) than did J-type hooks (41%). Hook location was directly correlated with mortality; all mortalities involved hook damage to the visceral region. A 10% postrelease mortality rate was observed for fish caught on both offset circle and J-type hooks. All mortalities occurred within 5 d postrelease. Survival was enhanced when deeply embedded hooks were left in place rather than removed from the visceral tissue. Hook-caught fish showed no reduction in growth when compared with control fish, but deeply hooked fish grew at a significantly lower rate than did fish hooked in the mouth. Angler success rates did not differ significantly between hook types. We recommend that catch-and-release mortality be incorporated into the management plan for white seabass.
Accuracy of Angler-Reported Harvest in Roving Creel Surveys
Authors: Mallison Craig T. , Cichra Charles E.
Published: August 2004

Harvest data obtained during roving creel surveys are often based on angler-reported information without validation. Angler creels were inspected following interviews during roving creel surveys on three Florida lakes. Comparisons between reported and counted harvest revealed significant differences for anglers targeting sunfish Lepomis spp. (22% error) and black crappie Pomoxis nigromaculatus (7% error). Differences were negligible for anglers targeting sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis), palmetto bass (male white bass × female striped bass), and largemouth bass Micropterus salmoides. Accuracy among species was inversely related to bag limit size; this was attributed to a combination of factors, including species, number and size of fish harvested, limit-conscious behavior of anglers, and differences among angler groups. Accuracy within species was not significantly influenced by the reported number of fish harvested or trip duration, nor was the interaction of the two significant. Daily total harvest estimates based on reported data were biased for sunfish (19% error) and black crappies (5% error), but correction factors were effective in reducing total errors to 2% for both species. Inspection of creels is recommended for all roving creel survey interviews when accuracy is critical to meeting study objectives. When moderate accuracy is sufficient, angler-reported harvest may be used if validated or adjusted with a correction factor if found to be inaccurate.
A Pipeline Model for Estimating Fishing Mortality in Salmon Mark-Selective Fisheries
Authors: Zhou Shijie
Published: August 2004

A model was developed to estimate fishing-induced mortality and exploitation rates for unmarked salmon Oncorhynchus spp. in mark-selective fisheries. This model is analogous to a pipeline, and the basic idea is similar to that of the change-in-ratio method used for estimating animal abundance. During spawning migration, a unidirectional movement occurs from the ocean to near shore and into freshwater. A series of nonselective and selective fisheries consequently catch these fish on their migration path. The model functions as follows: First, a cohort analysis is completed for the coded-wire-tagged fish to obtain their initial abundance and fishery-specific exploitation rate. Second, fishery-specific exploitation rates of unmarked fish are derived. Third, the initial abundance of unmarked fish is obtained from the total exploitation rate and escapement and then the ratio between the abundances of unmarked and marked fish is estimated for each fishery. Finally, the fishery-specific mortality of unmarked fish is estimated. The method assumes that the release mortality rates in selective fisheries are known. Methods for correcting potential bias are suggested. Sensitivity analyses show that the estimated exploitation rates of unmarked fish are less sensitive to bias in the release mortality rate than to bias in the estimated cohort size of marked fish. Bias in release mortality rates results in a diminishing bias of exploitation rates in sequential selective fisheries, but bias in the estimated cohort size results in an increasing bias. An example is given for Sandy River coho salmon O. kisutch in the lower Columbia River. This method does not require double index tagging and can presumably be applied to most fisheries. Some caveats in applying this model to salmon fishery management are given.
A Comparison of Injectable Fluorescent Marks in Two Genera of Darters: Effects on Survival and Retention Rates
Authors: Roberts James H. , Angermeier Paul L.
Published: August 2004

Visible implant elastomer (VIE) and injectable photonic dye (IPD), two types of injectable fluorescent marks, have shown promise in previous applications in a variety of fishes but have not been extensively tested on darters. We marked a species from each of two genera of darters, Percina and Etheostoma, in a laboratory experiment to determine the influence of VIE and IPD marks on survival and the influences of mark type, location, and color on mark retention. Short-term (≤80-d) survival was similar between marked and control specimens for both marks in both species. Over the long term (200–240 d), however, the survival rate for IPD-marked Roanoke darters P. roanoka was significantly lower than that for controls (50% versus 80%), whereas VIE-marked Roanoke darters had a survival rate (88%) similar to that of controls. Long-term survival of riverweed darters E. podostemone did not differ among groups. In Roanoke darters, the mark retention rate for IPD was significantly lower than that for VIE by day 80 of the experiment (80% versus 94%), and ventral IPD marks were retained with greater frequency than were dorsal IPD marks. In riverweed darters, retention was similar for VIE and IPD (79% versus 83%) in all body locations through day 240. In both species, yellow IPD marks exhibited higher retention rates than did green IPD marks, whereas the reverse was true for yellow and green VIE marks. Overall, VIE was a superior mark in the Percina representative but performed similarly to IPD in Etheostoma. Because of interspecific and intraspecific variability in mark performance, we recommend a pilot study before initiating field use of injectable marks in untested species.
Geographic Patterns of Genetic Differentiation among Collections of Green Sturgeon
Authors: Israel Joshua A. , Cordes Jan F. , Blumberg Marc A. , May Bernie
Published: August 2004

The population structure of green sturgeon Acipenser medirostris has not previously been evaluated, although commercial and bycatch harvests may be impacting multiple populations of this species. Molecular markers were used to distinguish between green and white sturgeon A. transmontanus and to examine the genetic variation among green sturgeon collected from four locations along the West Coast of the United States between San Pablo Bay, California, and the Columbia River, Washington. Verification that putative green sturgeon samples were not white sturgeon was accomplished with a diagnostic restriction fragment length polymorphism in the mitochondrial cytochrome b locus. Genetic variation in green sturgeon was investigated using six microsatellite loci developed from published primers. Allele frequencies, the fixation index FST, and observed heterozygosities were determined at three disomic and three tetrasomic loci amplified from fin tissue samples. Pairwise FST values of 0.005 and −0.002 indicated no genetic differentiation between the Klamath and Rogue River collections or the Columbia River and San Pablo Bay collections. All other FST values among pairs of collections ranged between 0.06 and 0.08 and indicated a significant difference between collections from the Rogue and Klamath rivers and those from San Pablo Bay and the Columbia River. These results and highly significant G-tests of genotypic differences between these pairs of collections support the existence of genetic structuring in this species along the Pacific coast. These data suggest that not all spawning populations have been identified and that additional genetic research will be necessary to adequately describe the population structure of green sturgeon before effective management plans can be developed.
Relationship between Lake-Record Weights of Fishes and Reservoir Area and Growing Season
Authors: Wilde Gene R. , Pope Kevin L.
Published: August 2004

We used information from an angler recognition program to assess the relationship between lake-record weights of freshwater fishes captured by Texas anglers and two predictors of fish production and growth: reservoir surface area and growing-season length. The lake-record weights of two species, largemouth bass Micropterus salmoides and flathead catfish Pylodictis olivaris, were directly related to the logarithm of surface area. The record weights of all species studied were unrelated to growing-season length. Regardless of the statistical significance of individual correlations, there was a significant excess of positive correlations across all species between lake-record weights of fish and log surface area. This indicates the presence of a general relationship between the record weights of fish and reservoir area. Our results suggest that record weights of fish may be constrained by reservoir surface area.
Effectiveness of Habitat Manipulation for Wild Salmonids in Wyoming Streams
Authors: Binns N. Allen
Published: August 2004

Habitat manipulation is commonly used to enhance habitat and stocks of fluvial trout of the genera Oncorhynchus, Salmo, and Salvelinus, but questions have been raised about the effectiveness of such work. Consequently, I analyzed wild trout abundance, biomass, and habitat before and after habitat manipulations among 30 projects done by the Wyoming Game and Fish Department. Abundance and biomass of trout increased following habitat manipulation among most of the projects. Excessive angler harvest prevented an increase at three projects, and drought hindered fish response in a fourth stream. At a fifth project, the trout population decreased after intense cattle grazing degraded project structures. Instream structures proved durable. Only one project, which featured wire trash catchers in a fourth-order mountain stream, suffered failure of habitat manipulation devices. Cover for trout and residual pool depth significantly increased following projects, whereas eroding banks significantly decreased. Both timber and log check dams consistently produced good pools, but rock check dams did not. Mean per project cost statewide was US$39,230/mi. These results demonstrate that well-built, properly located, and properly maintained instream structures can provide better habitat and increase stocks of trout in carefully selected reaches, thus satisfying public and agency expectations for fishery improvement and gaining time to correct watershed problems.
Factors That May Be Influencing Nonnative Brook Trout Invasion and Their Displacement of Native Westslope Cutthroat Trout in Three Adjacent Southwestern Montana Streams
Authors: Shepard Bradley B.
Published: August 2004

I examined trends in community structure and abundance in populations of native westslope cutthroat trout (WCT) Oncorhynchus clarki lewisi and nonnative brook trout Salvelinus fontinalis and fish habitat characteristics in three adjacent southwestern Montana streams during 1988, 1993–1995, and 1997–1999. Delano and upper Jerry creeks had relatively undisturbed riparian forests, whereas Libby Creek's riparian forest was harvested along much (0.9 km) of the stream during 1971. Libby Creek had higher summer water temperatures (average daily temperatures were 1–2°C higher) than Delano Creek. Libby Creek also contained more woody debris, a higher percentage of fine sediments within the streambed, and a higher proportion of pool habitats than Delano and upper Jerry creeks. Brook trout dominated the trout community in Libby Creek (78– 91%), whereas WCT dominated in Delano and upper Jerry creeks (77–100%). Similarly, brook trout densities were significantly higher in Libby Creek, and WCT densities were significantly greater in Delano and upper Jerry creeks. These data suggest that brook trout invasion and the displacement of WCT in these streams may have been influenced by water temperature, debris and pool frequencies, erosion and deposition of fine sediments on the streambed, or some combination of these factors. Past research has linked changes in these physical parameters to riparian timber harvest activities. More research is needed to better quantify potential influences of abiotic factors on brook trout invasion and the subsequent displacement of WCT. Until such research is completed, resource managers who wish to protect and conserve stream populations of native WCT should consider the effects of land management and fish restoration activities on the aforementioned stream habitat conditions, especially in systems that contain or could potentially be invaded by nonnative brook trout.
Bias and Precision of Estimates from an Age-Structured Stock Assessment Program in Relation to Stock and Data Characteristics
Authors: Yin Yanshui , Sampson David B.
Published: August 2004

Assessments for many U.S. Pacific coast groundfish stocks have been developed using the statistical catch-at-age method known as Stock Synthesis. This study used Monte Carlo simulation and a fractional factorial experiment to evaluate the effects of input data errors and stock characteristics on bias and precision in estimates of ending exploitable biomass, rate of fishing mortality, depletion, and other output variables. Nine factors were examined: length of the data series, rate of natural mortality, shape of the fishery selectivity curve, trend in fishing mortality, recruitment pattern, and level of sampling error in the data for catch, fishing effort, a survey biomass index, and sample size for fishery and survey age compositions. Length of the data series, age composition sample size, survey biomass variability, and fishing effort variability were the most influential factors for most of the output variables. The estimates of depletion had the least bias and the estimates of starting biomass the smallest variability; the estimates of ending recruitment had the greatest bias and largest variability. For all the output variables examined the estimates appeared to be median-unbiased. For the conditions considered in the experiment, it appears that the accuracy of assessment estimates for ending exploitable biomass and projected catch would be more readily improved by increased age composition sampling than by comparable (but much more expensive) improvements in survey estimates of stock biomass.
The Efficiency of a Bycatch Reduction Device Used in Skimmer Trawls in the Florida Shrimp Fishery
Authors: Warner Daniel A. , McMillen-Jackson Anne L. , Bert Theresa M. , Crawford Charles R.
Published: August 2004

Of principal concern to those who regulate shrimp harvesting gear are the quantity and composition of nontargeted species (bycatch) harvested by any allowable gear type. The use of skimmer trawls in the Florida shrimp fishery is a contested issue, in part because little bycatch characterization data exist for this gear. We characterized skimmer trawl bycatch and evaluated the efficiency of the Florida Fisheye (FFE) bycatch reduction device in a skimmer trawl typically used by commercial fishermen in Apalachicola Bay, Florida, an area with an active fishery for white shrimp Litopenaeus setiferus (also known as Penaeus setiferus). In general, the finfish bycatch in a 4.9-m-long × 3-m-wide skimmer trawl net equipped with an FFE was significantly lower than that in an identical net towed simultaneously but without the FFE; the two nets, however, did not differ in the quantity of shrimp retained. The magnitude of the reduction in bycatch in the FFE-equipped net varied between seasons (spring and fall) and among finfish species and, in the case of silver seatrout Cynoscion nothus and Atlantic croaker Micropogonias undulatus, between size- (i.e., age-) groups. Preliminary tests of FFEs in skimmer trawls in North Carolina also show a reduction in bycatch; we provide further details on how bycatch reduction devices work in skimmer trawls. Overall, our results indicate that skimmer trawls equipped with FFEs should compare favorably with other allowable shrimping gear.
Use of Ultrasound Imaging and Steroid Concentrations to Identify Maturational Status in Adult Steelhead
Authors: Evans Allen F. , Fitzpatrick Martin S. , Siddens Lisbeth K.
Published: August 2004

We sought to develop a rapid, noninvasive, and accurate method for distinguishing prespawn (mature or maturing) adult steelhead (anadromous rainbow trout Oncorhynchus mykiss) from postspawn adults (kelts). Ultrasound images of gonads were collected, and levels of plasma testosterone (T), 11-ketotestosterone (11-KT), and 17α-hydroxy-20β-dihydroxyprogesterone (DHP) were determined for adult steelhead before and after spawning. Results demonstrated that ultrasound images provided quantifiable selection criteria (number of eggs or gonad size) for the identification of prespawn versus postspawn adults. Mature females were easily identifiable by the presence of numerous, well-developed eggs. Conversely, only a few mature eggs remained in the body cavities of female kelts. Ultrasound investigation of the maximum testis area demonstrated that testes undergo substantial size changes following spawning. Mean maximum testis area was 2.86 cm2 in prespawn males and 0.62 cm2 male kelts. Distributions of testis measurements between the two maturational types did not overlap, and results of a discriminant function analysis suggested that a classification criterion (threshold) of 1.25 cm2 could accurately distinguish prespawn males from kelts. Median concentrations of T, 11-KT, and DHP were significantly higher in prespawn males (49.6, 78.4, and 13.0 ng/mL, respectively) than in kelts (<1.2, 6.6, and 1.6 ng/mL), providing an independent verification of the ultrasound technique. Despite the high degree of corroboration between ultrasound measurements of gonad size and plasma steroid levels, application of ultrasound imaging may result in some classification error (a few percentage points) if substantial gonad mass is retained in the body cavity after spawning. Use of ultrasound to accurately identify postspawn steelhead is an important first step towards development of effective kelt management practices in the Columbia River basin.
Experimental Assessment of Age-0 Largemouth Bass and Juvenile Bluegill Competition in a Small Impoundment in Virginia
Authors: Brenden Travis O. , Murphy Brian R.
Published: August 2004

Previous research has found that early ontogenetic stages of largemouth bass Micropterus salmoides and bluegills Lepomis macrochirus may compete for food resources in small impoundments in northern-latitudes. We experimentally assessed whether competition also might occur in a southern-latitude system by stocking fish allopatrically and sympatrically in 1.0-m3 cages within a small impoundment in Virginia and monitoring fish growth and diets. Although growth was not significantly different between bluegills stocked with and without largemouth bass, largemouth bass grew significantly larger when stocked alone than when stocked with bluegills. Although bluegills maintained similar diets in terms of sizes, numbers, and types of items consumed, largemouth bass stocked alone consumed fewer but larger items than those stocked with bluegills. Further, largemouth bass consumed higher volumetric proportions of Diptera larvae and Odonata nymphs when stocked alone than when stocked with bluegills. Of these two items, only Diptera larvae constituted a large portion of bluegill diets. Competition between largemouth bass and bluegills apparently occurs in both southern- and northern-latitude small impoundments. Competition with bluegills may result in a competitive juvenile bottleneck for largemouth bass in regions where overwinter mortality is size related, which could affect management (i.e., stocking, establishing harvest regulations) of small-impoundment fisheries.
Evaluation of Shortnose Sturgeon Spawning in the Pinopolis Dam Tailrace, South Carolina
Authors: Duncan Michelle S. , Isely J. Jeffery , Cooke Douglas W.
Published: August 2004

Fifty egg mats and up to five D-shaped plankton nets were deployed in the tailrace of Pinopolis Dam at river kilometer 77 on the Cooper River, South Carolina, to evaluate the spawning activity of shortnose sturgeon Acipenser brevirostrum. Spawning times were estimated by back-calculation based on developmental phase. Eggs were collected on 17 of 21 d sampled continuously from March 4 through March 25, 2002, when water temperatures were 10–16°C. A total of 31 shortnose sturgeon eggs were collected from egg mats. An additional 338 shortnose sturgeon eggs and 1 newly hatched yolk sac larva were collected from plankton nets. A minimum of 20 spawning events occurred in the tailrace during the 2002 spawning season. No relationship between mean daily discharge and spawning date was observed. Shortnose sturgeon spawned more often during the night than at any other time of day independent of generation.
Spatial Considerations in the Management of Atlantic Cod off Nova Scotia, Canada
Authors: Fu Caihong , Fanning L. Paul
Published: August 2004

A spatial, age-structured population dynamics model was developed for a stock of Atlantic cod Gadus morhua off eastern Nova Scotia to examine alternative management options. The model incorporates stock structure, seasonal migration, predation, Allee effects, and variation in natural mortality. The simulated dynamics of two substocks were compared under three management options: (1) historical catch levels; (2) combined management (substocks are managed as one unit) with a constant fishing mortality rate (F) of 0.4; and (3) separated management (substocks are managed individually) with the same F level. Three major conclusions emerged from the simulations. First, the population dynamics under historical catch levels tended to vary widely from complete extinction to a fourfold increase. Second, constant-F management produced stable population dynamics, reduced the probability of stock decline, and yielded a higher average catch. Third, the combined management option resulted in overfishing the more vulnerable substock; separated management helped to prevent the more vulnerable substock from collapse, but its performance was compromised when there was net immigration to the more vulnerable substock.
Status of Lake Trout Rehabilitation on Six Fathom Bank and Yankee Reef in Lake Huron
Authors: Madenjian Charles P. , Desorcie Timothy J. , McClain Jerry R. , Woldt Aaron P. , Holuszko Jeffrey D. , Bowen Charles A.
Published: August 2004

Six Fathom Bank, an offshore reef in the central region of Lake Huron's main basin, was stocked annually with hatchery-reared lake trout Salvelinus namaycush during 1985–1998, and nearby Yankee Reef was stocked with hatchery-reared lake trout in 1992, 1997, and annually during 1999–2001. We conducted gill-net surveys during spring and fall to evaluate performances of each of the various strains of lake trout, as well as the performance of the entire lake trout population (all strains pooled), on these two offshore reefs during 1992–2000. Criteria to evaluate performance included the proportion of “wild” fish within the population, spawner density, adult survival, growth, maturity, and wounding rate by sea lamprey Petromyzon marinus. Although naturally reproduced age-0 lake trout fry were caught on Six Fathom Bank and Yankee Reef, wild lake trout did not recruit to the adult population to any detectable degree. The density of spawning lake trout on Six Fathom Bank (>100 fish/305 m of gill net) during 1995–1998 appeared to be sufficiently high to initiate a self-sustaining population. However, annual mortality estimates for all lake trout strains pooled from catch curve analyses ranged from 0.48 to 0.62, well exceeding the target level of 0.40 suggested for lake trout rehabilitation. Annual mortality rate for the Seneca Lake strain (0.34) was significantly lower than that for the Superior–Marquette (0.69) and Lewis Lake (0.69) strains. This disparity in survival among strains was probably attributable to the lower sea-lamprey-induced mortality experienced by the Seneca Lake strain. The relatively high mortality experienced by adult lake trout partly contributed to the lack of successful natural recruitment to the adult population on these offshore reefs, but other factors were probably also involved. We recommend that both stocking of the Seneca Lake strain and enhanced efforts to reduce sea lamprey abundance in Lake Huron be continued.
Impacts of Small Club Tournaments on Black Bass Populations in Connecticut and the Effects of Regulation Exemptions
Authors: Edwards Gordon P. , Neumann Robert M. , Jacobs Robert P. , O'Donnell Eileen B.
Published: August 2004

Annual tournament-associated mortality of largemouth bass Micropterus salmoides and smallmouth bass M. dolomieu (≥30 cm) was quantified at Mansfield Hollow Reservoir and Gardner Lake, Connecticut, during 2001 and 2002 to determine the effects of tournaments on black bass populations. Nontournament and tournament anglers followed a 30-cm minimum length limit during both years. Tournament anglers—but not nontournament anglers—were exempt from new, more restrictive regulations (a 30–41-cm protected slot length limit at Mansfield Hollow Reservoir; a 41-cm minimum length limit at Gardner Lake) imposed in 2002. Annual tournament-associated mortality of largemouth bass was 2.4–8.4% of total annual mortality, 1.0–3.2% of the population size, and 2.0–20.8% of annual fishing mortality. For smallmouth bass, tournament-associated mortality was approximately 7% of total annual mortality, 4% of the population size, and 29–52% of annual fishing mortality. Based on the levels of total annual mortality, annual fishing mortality, and annual tournament-associated mortality, impacts of tournament angling appeared low in these two lakes. Tournament-associated impacts would have been lower if anglers were prohibited from exemptions. If exemptions were prohibited year-round or only during the summer, 80–94% of the tournament catch would have been immediately released. Relative to fishing effort, tournament anglers in Connecticut contributed a greater proportion of annual fishing mortality than nontournament anglers. In lakes where tournament-associated mortality is high, prohibiting exemptions (especially during summer) may help to reduce tournament-associated mortality. In lakes with low tournament impacts, allowing exemptions (except during summer) may protect tournament angling opportunities for most of the fishing season, while at the same time decreasing tournament-associated mortality during the warmest months.
The Importance of Beaver Ponds to Coho Salmon Production in the Stillaguamish River Basin, Washington, USA
Authors: Pollock Michael M. , Pess George R. , Beechie Timothy J. , Montgomery David R.
Published: August 2004

The use of beaver Castor canadensis ponds by juvenile coho salmon Oncorhynchus kisutch and other fishes has been well established. However, the population-level effects on coho salmon resulting from the widespread removal of millions of beaver and their dams from Pacific Coast watersheds have not been examined. We assessed the current and historic distributions of beaver ponds and other coho salmon rearing habitat in the Stillaguamish River, a 1,771-km2 drainage basin in Washington and found that the greatest reduction in coho salmon smolt production capacity originated from the extensive loss of beaver ponds. We estimated the current summer smolt production potential (SPP) to be 965,000 smolts, compared with a historic summer SPP of 2.5 million smolts. Overall, current summer habitat capacity was reduced by 61% compared with historic levels, most of the reduction resulting from the loss of beaver ponds. Current summer SPP from beaver ponds and sloughs was reduced by 89% and 68%, respectively, compared with historic SPP. A more dramatic reduction in winter habitat capacity was found; the current winter SPP was estimated at 971,000 smolts, compared with a historic winter SPP of 7.1 million smolts. In terms of winter habitat capacity, we estimated a 94% reduction in beaver pond SPP, a 68% loss in SPP of sloughs, a 9% loss in SPP of tributary habitat, and an overall SPP reduction of 86%. Most of the overall reduction resulted from the loss of beaver ponds. Our analysis suggests that summer habitat historically limited smolt production capacity, whereas both summer and winter habitats currently exert equal limits on production. Watershed-scale restoration activities designed to increase coho salmon production should emphasize the creation of ponds and other slow-water environments; increasing beaver populations may be a simple and effective means of creating slow-water habitat.
Fish Total Length Measurement Error from Recreational Anglers: Causes and Contribution to Noncompliance for the Mille Lacs Walleye Fishery
Authors: Page Kevin S. , Grant Gerold C. , Radomski Paul , Jones Thomas S. , Bruesewitz Richard E.
Published: August 2004

To estimate angler noncompliance with size limits due to measurement error by anglers, we used estimates of measurement error derived from (1) lengths of walleye Sander vitreus tagged and measured by biologists subsequently caught and voluntarily measured by anglers and (2) from dead walleyes of known length that anglers voluntarily measured during interviews at lake access sites. We also investigated the potential for postmortem changes in fish length. Monte Carlo simulations suggested that angler measurement error accounted for 41–100% of observed angler noncompliance with a 14-in to 16-in harvest slot limit for Mille Lacs lake, Minnesota. Simulations underestimated harvest (retention) rates for walleyes of lengths approaching the harvest slot boundaries compared with actual measures by anglers of the tagged fish they caught; this suggests greater attentiveness of anglers at measuring fish near the slot limits or angler intent to retain protected fish. When reporting total lengths of the tagged walleyes they caught, more anglers rounded measurements to 1-in or 1/2-in increments, whereas more anglers rounded to 1/4-in or 1/8-in increments when reporting lengths of tagged walleyes they retained or when measuring dead fish during interviews. Length measurement errors may be compounded by postmortem physical changes in harvested fish. Although postmortem changes will not influence angler retention of fish, temporal changes in the physical condition of fish may influence whether a creel clerk or conservation officer observes a fish as noncompliant. Understanding the level and characteristics of measurement error is important for understanding the factors influencing angler noncompliance with size limits.
Effects of Holding Environment and Exercise Conditioning on Swimming Performance of Southwestern Native Fishes
Authors: Ward David L. , Hilwig Kara D.
Published: August 2004

Rare native fish are often reared in ponds or tanks at hatcheries for later stocking into streams with depleted populations. Fish reared in standing water may experience increased stress, downstream displacement, or high predation mortality when released into lotic environments. We compared the swimming performance of captive fish held in standing water, captive fish exercised in flowing water, and wild fish captured from a stream to evaluate the effects of exercise conditioning and holding environment on swimming performance. The swimming performance of flannelmouth sucker Catostomus latipinnis, bonytail Gila elegans, razorback sucker Xyrauchen texanus, and spikedace Meda fulgida held in standing water increased by 10, 15, 26, and 40%, respectively, after exercise conditioning in flowing water (10–100 cm/s) for as little as 10 d. Exercising fish reared in standing water may improve swimming performance and increase survival.
Age Structure and Mortality of Walleyes in Kansas Reservoirs: Use of Mortality Caps to Establish Realistic Management Objectives
Authors: Quist Michael C. , Stephen James L. , Guy Christopher S. , Schultz Randall D.
Published: August 2004

Age structure, total annual mortality, and mortality caps (maximum mortality thresholds established by managers) were investigated for walleye Sander vitreus (formerly Stizostedion vitreum) populations sampled from eight Kansas reservoirs during 1991–1999. We assessed age structure by examining the relative frequency of different ages in the population; total annual mortality of age-2 and older walleyes was estimated by use of a weighted catch curve. To evaluate the utility of mortality caps, we modeled threshold values of mortality by varying growth rates and management objectives. Estimated mortality thresholds were then compared with observed growth and mortality rates. The maximum age of walleyes varied from 5 to 11 years across reservoirs. Age structure was dominated (≥72%) by walleyes age 3 and younger in all reservoirs, corresponding to ages that were not yet vulnerable to harvest. Total annual mortality rates varied from 40.7% to 59.5% across reservoirs and averaged 51.1% overall (SE = 2.3). Analysis of mortality caps indicated that a management objective of 500 mm for the mean length of walleyes harvested by anglers was realistic for all reservoirs with a 457-mm minimum length limit but not for those with a 381-mm minimum length limit. For a 500-mm mean length objective to be realized for reservoirs with a 381-mm length limit, managers must either reduce mortality rates (e.g., through restrictive harvest regulations) or increase growth of walleyes. When the assumed objective was to maintain the mean length of harvested walleyes at current levels, the observed annual mortality rates were below the mortality cap for all reservoirs except one. Mortality caps also provided insight on management objectives expressed in terms of proportional stock density (PSD). Results indicated that a PSD objective of 20–40 was realistic for most reservoirs. This study provides important walleye mortality information that can be used for monitoring or for inclusion into population models; these results can also be combined with those of other studies to investigate large-scale differences in walleye mortality. Our analysis illustrates the utility of mortality caps for monitoring walleye populations and for establishing realistic management goals.
Diamonds from the Pressure Cooker—Science or Science Fiction?
Authors: Sachdev Hermann
Published: August 2004

Questions are raised about some of the arguments and methods described by Q. Chen and co‐workers in their reports on the synthesis of diamonds under mild conditions: Are the data provided sufficient proof of a new synthetic method? Where is the evidence of the proposed reaction intermediates? Is there another cause for the formation of diamond?
A family‐based association study of congenital left‐sided heart malformations and 5,10 methylenetetrahydrofolate reductase
Authors: McBride Kim L. , Fernbach Susan , Menesses Andres , Molinari Laura , Quay Ellinor , Pignatelli Ricardo , Towbin Jeffrey A. , Belmont John W.
Published: August 2004

BACKGROUND

Aortic valve stenosis (AVS), coarctation of the aorta (CoA), and hypoplastic left heart syndrome (HLHS) are obstructive malformations of the left ventricular outflow tract that account for a significant proportion of infant mortality. Two previous small case‐control studies suggested methylenetetrahydrofolate reductase (MTHFR) polymorphisms may be associated with this group of malformations.

METHODS

We used a family‐based association design with inclusion criteria of nonsyndromic diagnosis of AVS, CoA, and HLHS, powered to detect an odds ratio for the heterozygote of <1.5. A total of 207 affected offspring‐parent trios were genotyped by restriction fragment length polymorphisms at the two common polymorphic loci C677T and A1298C.

RESULTS

Error rate estimation based on replicate samples was 0.76%. Mendelian inconsistency at either polymorphism was noted in 10 trios, for a calculated undetected error rate of 1.95%. A total of 197 trios were analyzed using the transmission disequilibrium test. Significant association was not found between both the C677T or A1298C polymorphisms and presence of a heart defect, whether analyzed as a group, or by sex, ethnicity, or specific diagnosis. A log‐linear analysis did not find increased relative risk based on the maternal genotype.

CONCLUSIONS

We were unable to replicate previous association studies and concluded that neither the affected nor the maternal MTHFR genotype, by itself, is a major risk factor for congenital left ventricular outflow tract malformations. Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.
Protein partitioning driven by excluded‐volume interactions in an aqueous nonionic micellar—gel system
Authors: van Roosmalen Dick , Lazzara Matthew J. , van den Broeke Leo J.P. , Keurentjes Jos T.F. , Blankschtein Daniel
Published: August 2004

The separation and purification of biomolecules in aqueous media driven by excluded‐volume interactions is a well‐established concept. In this article we propose a new separations method, based on excluded‐volume principles, consisting of an aqueous micellar—gel system (AMGS). Specifically, an outer aqueous phase containing cylindrically shaped micelles of the nonionic surfactant n‐decyl tetra (ethylene oxide) (C10E4) is physically separated from an inner aqueous phase defined by the interior volume of gel beads, from which the micelles are completely excluded because of their shape and size. In the AMGS, the concentration of the micelles outside the gel beads is sufficiently high that the volume excluded to a biomolecule in the solution external to the gel beads is much larger than that within the gel beads. Accordingly, when biomolecules are introduced into the AMGS, they partition preferentially into the gel‐bead phase, according to their sizes, as a result of the greater effect of the excluded‐volume interactions with the C10E4 micelles present in the aqueous phase outside the gel beads. The new AMGS is more versatile and adaptable than the conventional two‐phase aqueous C10E4 micellar system because the micelle volume fraction is independent of the temperature and because the effects of entrainment are eliminated. After demonstrating the experimental feasibility of creating the new AMGS, the three proteins myoglobin, ovalbumin, and BSA‐FITC, and the enzyme G6PD, were partitioned in the AMGS and their partitioning behavior was found to follow the experimental excluded‐volume trends dictated by the interactions of the biomolecules with the C10E4 micelles. Specifically, the measured partition coefficients of the four biomolecules into the micellar phase were found to be less than unity and to decrease with increasing biomolecule size. A theoretical description of the partitioning behavior of the biomolecules in the new AMGS was formulated, based on excluded‐volume considerations, and the predicted biomolecule partition coefficients were found to compare favorably with those measured for the four biomolecules studied. © 2004 Wiley Periodicals, Inc.
A novel approach for the extraction of herbicides and pesticides from water using liquid‐core microcapsules
Authors: Wyss A. , Cordente N. , von Stockar U. , Marison I.W.
Published: August 2004

A novel perstraction system using liquid‐core microcapsules for pesticide and herbicide removal from aqueous environments is proposed. The microcapsules contain an oil, dibutyl sebacate, surrounded by a hydrogel membrane. The extraction efficiency of the capsules was demonstrated with atrazine, methylparathion, ethylparathion, and 2,4‐dichloro‐phenoxyacetic acid. The results show that all of the tested compounds could be rapidly extracted, typically 75% extraction within 10 minutes using a capsule: liquid volume ratio of only 3.5% for ethylparathion, and that the rate of extraction increased with increasing hydrophobicity of the compound to be extracted. Higher rates of extraction could be achieved by changing the capsule: liquid volume ratio.

The effect of different liquid core solvents, size of capsules, agitation rate, and treatment with complexing agents on the properties of the microcapsules and extraction rate were studied.

Capsules of a diameter smaller than 0.800 mm show little external resistance to mass transfer. The main resistance to mass transfer of the pesticides/herbicides was found to reside in the hydrogel membrane composed of cross‐linked alginate/polyacrylamide. Removal of divalent cations from the membrane by the addition of citrate, resulted in a 50% increase in the mass transfer coefficient, probably as a result of solubilization and exo‐diffusion of alginate. © 2004 Wiley Periodicals, Inc.
Optimal operating mode for enantioseparation of SB‐553261 racemate based on simulated moving bed technology
Authors: Wongso Faldy , Hidajat K. , Ray Ajay K.
Published: August 2004

The performance of the simulated moving bed (SMB) technology and its modification, the Varicol process, was optimized using an experimentally verified model for the enantioseparation of SB‐553261 racemate. Single and multiobjective optimizations have been carried out for both existing as well as design stage and their efficiencies were compared. The optimization problem involves a relatively large number of decision variables, both continuous variables such as flow rates, switching time and length of the columns, as well as discrete variables like number and distribution of columns. A state‐of‐the‐art new optimization technique based on a genetic algorithm (nondominated sorting genetic algorithm with jumping genes) was utilized which allows handling of these complex optimization problems. The optimization results showed that significant improvement could be made to the chiral drug separation process using both the SMB and the Varicol process. It was found that the performance of a Varicol process is superior to that of a SMB process in terms of treating more feed using less desorbent or increasing productivity while at the same time achieving better product quality. Optimum results were explained using equilibrium theory by locating them in the pure separation region. © 2004 Wiley Periodicals, Inc.
Meta-analysis of non-sentinel node metastases associated with micrometastatic sentinel nodes in breast cancer
Authors: Cserni G , Gregori D , Merletti F , Sapino A , Mano M P , Ponti A , Sandrucci S , Baltás B , Bussolati G
Published: August 2004

Background

The need for further axillary treatment in patients with breast cancer with low-volume sentinel node (SN) involvement (micrometastases or smaller) is controversial.

Methods

Twenty-five studies reporting on non-SN involvement associated with low-volume SN involvement were identified using Medline and a meta-analysis was performed.

Results

The weighted mean estimate for the incidence of non-SN metastases after low-volume SN involvement is around 20 per cent, whereas this incidence is around 9 per cent if the SN involvement is detected by immunohistochemistry (IHC) alone. Subset analyses suggest that studies with axillary dissection after any type of SN involvement result in somewhat higher estimates than studies allowing omission of axillary clearance, as do studies with more detailed histological evaluation of the SN compared with those with a less intensive histological protocol. Higher-quality papers yield lower pooled estimates than lower-quality papers.

Conclusion

The risk of non-SN metastasis with a low-volume metastasis in the SN is around 10–15 per cent, depending on the method of detection of SN involvement. This should be taken into account when assessing the risk of omission of axillary dissection after a positive SN biopsy yielding micrometastatic or immunohistochemically positive SNs.