bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Density Dependence in Growth Patterns of Ceded Territory Walleye Populations of Northern Wisconsin: Effects of Changing Management Regimes
Authors: Sass Greg G. , Hewett Steven W. , Beard T. Douglas , Fayram Andrew H. , Kitchell James F. 
Published: December 2004

Abstract
We assessed density-related changes in growth of walleye Sander vitreus in the ceded territory of northern Wisconsin from 1977 to 1999. We used asymptotic length (L∞), growth rate near t0 (ω), and body condition as measures of walleye growth to determine the relationship between growth and density. Among lakes, there was weak evidence of density-dependent growth: Adult density explained only 0–6% of the variability in the growth metrics. Within lakes, growth was density dependent, L∞, ω, and body condition of walleyes changing with density for 69, 28, and 62% of the populations examined, respectively. Our results suggest that walleye growth was density dependent within individual lakes. However, growth was not coherently density dependent among lakes, which was possibly due to inherent differences in the productivity, surface area, forage base, landscape position, species composition, and management regime of lakes in the ceded territory. Densities of adult walleyes averaged 8.3 fish/ha and did not change significantly during 1990–1999. Mean L∞ and body condition of walleyes were significantly higher before 1990 than after 1990, which may indicate an increase in density due to changes in management regimes. The observed growth changes do not appear to be a consequence of the statewide 15-in minimum size limit adopted in 1990 but rather a response to the treaty rights management regime. We conclude that walleye growth has the potential to predict regional-scale adult walleye densities if lake-specific variables are included in a model to account for regional-scale differences among walleye populations and lakes.
Microsatellite Variation Indicates Population Genetic Structure of Bocaccio
Authors: Matala Andrew P. , Gray A. K. , Gharrett A. J. , Love M. S. 
Published: December 2004

Abstract
The California groundfish fishery has recently experienced a severe decline in both the biomass and harvest of bocaccio Sebastes paucispinis. The conservation and management actions necessary to reverse this trend require biological data, including information on the population structure, that reflect the basis of productivity. Using microsatellite loci, we conducted a population genetic analysis of bocaccio with samples from waters ranging from British Columbia to Baja California. A log-likelihood test of homogeneity of allele frequencies over the entire data set was significant, although partitioning variation by FST analysis revealed no statistically significant geographic divergence among populations, and no evidence of a geographic cline of structure was detected in a Mantel test. By partitioning the heterogeneity among populations into homogeneous groups of adjacent populations, we observed structure related to geographic location that could be consistent with the divisions of current regimes among the California Current system, a neighborhood model of isolation and limited gene flow, or both. Resolving more detailed structure was not possible with the numbers of samples and collections available, but our observations indicate that caution should be exercised in making conservation or management decisions that do not consider genetic structure or that assume its absence.
Comparison of Fish Density Estimates from Repeated Hydroacoustic Surveys on Two Wyoming Waters
Authors: Gangl R. Scott , Whaley Roy A. 
Published: December 2004

Abstract
The ability to actively sample fish populations is a major advantage of hydroacoustic assessment. This technique does not affect fish behavior, and it typically produces more precise abundance estimates than do other gears. Thus, hydroacoustic surveys repeated on a closed population should produce similar fish density estimates. We sought to demonstrate this on inland waters using multiplexed side- and down-looking transducers and target-tracking enumeration methods. To test the repeatability of hydroacoustically derived fish density estimates, we conducted complete hydroacoustic surveys daily over three consecutive days on two Wyoming reservoirs, with a parallel transect design at one reservoir and a zigzag design at the other; this mimicked two designs commonly used during routine hydroacoustic surveys. These repeated surveys were performed on each reservoir monthly from April to September 2001. We used a Kruskal–Wallis test to detect significant differences in fish density estimates among repeated surveys for each lake during each month. There were no significant differences among daily surveys when sampling conditions were constant. During periods of increased wind we increased the aiming-angle of the side-looking transducer to minimize wind noise interference at the lake surface. This produced significantly lower density estimates than on calm days. We concluded that sampling under marginal conditions affected the results of the survey and inhibited the comparability of samples over time.
Postrelease Rate of Loss of Juvenile Red Drum Stocked out of Season in the Chassahowitzka National Wildlife Refuge, Florida
Authors: Sherwood Edward T. , Murie Debra J. , Parkyn Daryl C. 
Published: December 2004

Abstract
Rates of loss of juvenile red drum Sciaenops ocellatus (∼85 mm total length) stocked out of season were estimated using hatchery releases and ultrasonically tagged fish in Pumpkin and May creeks in the Chassahowitzka National Wildlife Refuge on the Gulf coast of Florida. In Pumpkin Creek, approximately 7,000 of the 10,000 fish released on 27 June 2000 survived combined transport mortality (2%) and 24-h acute mortality (28 ± 8.7% [mean ± SE] n = 6). In May Creek, approximately 5,100 of the 10,000 fish released on 29 June 2000 survived combined transport (7.5–10%) and 24-h acute (44 ± 0%, n = 2) mortality. Catch curve estimates of the instantaneous “rate of loss” (mortality or emigration) within 5 d were 0.46/d and 0.50/d for Pumpkin and May creeks, respectively. Red drum with ultrasonic transmitters (n = 12) also rapidly “disappeared” from the creeks within 4 d after release. These are the first estimates of postrelease rate of loss for juvenile red drum released out of season on the west coast of Florida. Understanding the causes of this overall rapid rate of loss will be critical to evaluating the success of out-of-season releases of red drum in Florida.
Abundance and Demography of Channel Catfish in a Large Northern River
Authors: Haxton Tim , Punt Kirby 
Published: December 2004

Abstract
A northern population of channel catfish Ictalurus punctatus was assessed to ascertain the abundance and demographics of the population. Standardized trap-netting was conducted from 1997 to 2002 in six reaches of the Ottawa River. A total of 13,197 channel catfish were sampled. The relative stock density was 18.5% stock, 47.7% quality, 27.2% preferred, 4.4% memorable, and 0.5% trophy. Mean relative weight was 71 for all channel catfish combined and for the different size-classes it was 37 for stock, 61 for quality, 88 for preferred, 133 for memorable, and 120 for trophy. Growth was slow compared with that of more southerly populations but longevity was greater (ages of up to 26 years). Annual mortality was 15.7%. Population estimates ranged from 38,445 to 220,924 in the various reaches, and density ranged from 3.5 to 31.7/ha. Channel catfish are an abundant and underutilized species in the Ottawa River; however, given their life history traits, this fishery is susceptible to overexploitation.
Stock-Specific Migration Timing of Adult Spring–Summer Chinook Salmon in the Columbia River Basin
Authors: Keefer Matthew L. , Peery Christopher A. , Jepson Michael A. , Tolotti Kenneth R. , Bjornn Theodore C. , Stuehrenberg Lowell C. 
Published: December 2004

Abstract
An understanding of the migration timing patterns of Pacific salmon Oncorhynchus spp. and steelhead O. mykiss is important for managing complex mixed-stock fisheries and preserving genetic and life history diversity. We examined adult return timing for 3,317 radio-tagged fish from 38 stocks of Columbia River basin spring–summer Chinook salmon O. tshawytscha over 5 years. Stock composition varied widely within and between years depending on the strength of influential populations. Most individual stocks migrated at similar times each year relative to overall runs, supporting the hypotheses that run timing is predictable, is at least partially due to genetic adaptation, and can be used to differentiate between some conspecific populations. Arrival timing of both aggregated radio-tagged stocks and annual runs was strongly correlated with river discharge; stocks arrived earlier at Bonneville Dam and at upstream dams in years with low discharge. Migration timing analyses identified many between-stock and between-year differences in anadromous salmonid return behavior and should aid managers interested in protection and recovery of evolutionarily significant populations.
Angling Pressure and Trout Catchability: Behavioral Observations of Brown Trout in Two New Zealand Backcountry Rivers
Authors: Young Roger G. , Hayes John W. 
Published: December 2004

Abstract
Angling pressure is increasing in many recreational trout fisheries throughout the world. There is a strong perception among anglers that trout become harder to catch after being disturbed by other anglers, thus affecting the quality of their angling experience. However, there is little scientific evidence to support or refute this perception. We measured the response to angling pressure in two rivers in New Zealand: The remote Ugly River and the more heavily fished Owen River. Both of these rivers have fisheries for brown trout Salmo trutta. The numbers of trout seen and caught over the length of four 3-d angling trips were compared between rivers. The behavioral responses to angling of naïve trout in the Ugly River were compared with those of Owen River trout and trout that had been angled previously from the Ugly River. The proportion of the trout population in the study reaches caught by two anglers after four 3-d trips was estimated as between 11% and 23% in the Owen River and up to 47% in the Ugly River. The most marked behavioral response to angling pressure was in the Ugly River, where trout that had been caught and released or merely disturbed by anglers were rarely seen over the following days. No such hiding response was observed in the Owen River. A learning response was also evident, as trout that had been fished previously were more likely to be scared by anglers or required smaller, low-profile flies before being caught than naïve trout. Faced with increasing angling pressure, anglers can perhaps cope with the observed learning response by improving their techniques to outsmart trout. However, the hiding response observed in the remote river indicates that controls on angling, such as access restrictions, may be required to maintain quality angling experiences in these wilderness fisheries.
Using Time-Lapsed Video to Estimate Survey Life for Area-under-the-Curve Methods of Escapement Estimation
Authors: Shardlow Tom 
Published: December 2004

Abstract
Accurate estimation of spawner populations for Pacific salmon Oncorhynchus spp. is critically important in stock assessment for fisheries management and science. Survey life (SL) is one essential component for area-under-the-curve (AUC) estimation of spawner populations. However, AUC spawner estimates often rely on a constant or borrowed estimate of SL because reliable estimates require extensive and costly annual field programs. Using a constant SL estimate can introduce serious bias when estimating spawner populations for sockeye salmon O. nerka as well as other salmon species. In this study, inexpensive video observations of redd residency time (RRT) of female sockeye salmon were used to approximate SL. Data from past studies indicate that RRT and SL are often close in duration for sockeye salmon, Chinook salmon O. tshawytscha, and coho salmon O. kisutch. In addition, SL estimates for male and female sockeye salmon are not significantly different. As a result, the RRT of female sockeye salmon, as observed by time-lapsed video recordings, can be used to provide an inexpensive annual estimate of sockeye salmon SL.
Simulated Impacts of Tournament-Associated Mortality on Largemouth Bass Fisheries
Authors: Allen M. S. , Rogers M. W. , Myers R. A. , Bivin W. M. 
Published: December 2004

Abstract
We used creel survey data combined with a simulation model to assess how tournament-associated mortality could increase exploitation of largemouth bass Micropterus salmoides and influence largemouth bass fisheries. We obtained estimates of total largemouth bass harvest (HARV) and total tournament catch (TC, i.e., the number of fish brought to judging stations) at nine lakes from Arkansas, Florida, and Texas. The ratio of TC to HARV exceeded 1.0 at five of the nine lakes studied and ranged from 0.35 to 5.18. We simulated potential tournament-associated mortality rates ranging from 0% to 70% applied to TC fish. Because exploitation was not known, we modeled harvest estimates to represent four potential exploitation rates (5, 15, 25, and 35%). The age-structured simulation model predicted that at three of nine lakes where TC/HARV ratios exceeded 3.0, tournament-associated mortality rates of 20–30% could cause 5–12% declines in the abundance of largemouth bass larger than 300 mm total length and resulted in declines in population size structure. At lakes with TC/HARV ratios of less than 1.0 (N = 4 lakes), the model predicted that tournament-associated mortality would have a negligible impact (i.e., &lt;5%) on the abundance of adult fish and population size structure, regardless of the tournament-associated mortality rate. Tournament-associated mortality may not significantly influence most largemouth bass fisheries. However, in lakes where tournament catch was substantially higher than harvest, tournament-associated mortality could encompass a large portion of fishing-associated mortality and would influence largemouth bass fisheries if harvest estimates corresponded to exploitation rates of 15% or more. Exploitation measures based solely on harvest may not reveal significant portions of fishing-associated mortality for fisheries where tournament catch can exceed harvest.
Anchor and Visible Implant Elastomer Tag Retention by Hatchery Rainbow Trout Stocked into an Ozark Stream
Authors: Walsh Maureen G. , Winkelman Dana L. 
Published: December 2004

Abstract
As part of a study to evaluate the stocking of rainbow trout Oncorhynchus mykiss in an Oklahoma Ozark stream, we tagged 2,542 hatchery-reared rainbow trout (123–366 mm total length) with individually numbered Floy FD-68B anchor tags and visible implant fluorescent elastomer (VIE) tags. We experimentally stocked double-marked rainbow trout into a small northeastern Oklahoma stream from November 2001 to March 2002 and resampled them monthly from December 2001 to October 2002 by electrofishing. Anchor tag retention was 91% through 6 months, and VIE tag retention was 96% through 6 months despite extensive handling of fish within 24 h of tagging. Based on the ease of application, high visibility, and high retention observed in this study, we recommend the use of VIE tags as a batch mark in similarly sized, similarly pigmented fish. The retention of VIE tags was slightly higher than that of anchor tags, and cost per fish was less for VIE than for anchor tags. However, VIE tags would have limited utility if numerous individual tags are necessary; therefore, we recommend anchor tags as individual marks in similarly sized salmonids. Retention for both tag types was relatively high and could be corrected for when estimating population parameters from tagging data.
Catalysis of hydrosilylation part XVIII. Pt(PPh3)2(CH2CH2) – a versatile catalyst for hydrosilylation of olefins
Authors: Marciniec B , Guliński J , Urbaniak W , Nowicka T , Mirecki J 
Published: December 2004

AbstractPt(PPh3)2(CH2CH2) appeared to be a versatile catalyst in hydrosilylation of alkenes (with 5–22 C atoms) as well as of functionalized alkenes such as allyl chloride, allylamine, allyl methacrylate and vinylsilanes. In comparison with a well‐known Speier catalyst or with Pt(PPh3)4, this complex is characterized by a very high effectiveness (activity and selectivity) and relative resistance to oxygenation and it may be applied in recycling runs with a minor induction period. The catalytic processes examined are of great industrial importance since they lead to a synthesis of alkylsilanes, disilylethanes and silane coupling agents.
Synthesis and characterization of rac‐1,2‐bis(palmitoyloxy)‐3‐propyl (2‐trimethylarsonioethyl)phosphonate, an arsenic‐containing phosphonolipid
Authors: Junk Thomas , Pappalardo Giuseppe C , Irgolic Kurt J 
Published: December 2004

AbstractArsenic analogs of lecithins (i.e. with replacement of nitrogen by arsenic in the choline group) are probably trace constituents of phospholipids in many organisms. Attempts to synthesize 1,2‐bis(palmitoyloxy)‐3‐propyl 2‐trimethylarsonioethyl phosphate (arsenolecithin) according to wellestablished procedures for the synthesis of the corresponding nitrogen compound failed. However, 1,2‐bis(palmitoyloxy)‐3‐propyl 2‐trimethylarsonioethylphosphonate, an arsenic‐containing phosphonolipid, was obtained in 16% yield by reacting 1,2‐bis(palmitoyloxy)‐3‐iodopropane with silver 2‐trimethylarsonioethylphosphonate in isopropanol. The precursors to the arsenic‐containing phosphonolipid were obtained by quaternization of trimethylarsine with diethyl 2‐bromoethylphosphonate, hydrolysis of the resulting product with concentrated hydrochloric acid, and reaction of the phosphonic acid with silver oxide to give silver 2‐trimethylarsonioethylphosphonate. Quaternization and hydrolysis proceeded almost quantitatively. The silver phosphonate was not isolated but was used in situ.
Laser photodissociation of organometallic compounds on a cryosubstrate
Authors: Kawasaki Masahiro , Nishi Nobuyuki 
Published: December 2004

AbstractThe photodissociation dynamics of organometallic compounds (tetramethyltin, trimethylgallium, trimethylindium and dimethylzinc) adsorbed on a quartz substrate at 100 K have been studied by time‐of‐flight mass spectrometry, detecting mainly CH3 photofragments. Shapes of the time‐of‐flight spectra depend on the flux of the dissociation laser at 193 nm and the thickness of multilayers of organometallic compounds. In thick layers, not only a low energy component but also a high energy component are observed in the time‐of‐flight spectrum of the CH3 photofragments. In thin layers, relaxation processes take place so quickly that the product time‐of‐flight profiles are characterized by a Maxwell–Boltzmann temperature profile.
New chelated complexes of bis‐β‐carboalkoxyethyltin(IV) dichloride with S‐benzyldithiocarbazate Schiff bases
Authors: Gopinathan Sarada , Degaonkar M P , Gopinathan C 
Published: December 2004

AbstractThe Schiff bases [H2SBSaD], [H2SBVD] and [H2SBND], derived by the condensation of S‐benzyldithiocarbazate and salicylaldehyde, 2‐hydroxy‐3‐methoxybenzaldehyde and 2‐hydroxy‐1‐naphthaldehyde respectively, react with diestertin dichlorides, R2SnCl2 [R=CH2CH2CO2CH3, CH2CH2CO2C2H5 or CH2CH2CO2C4H9] in 1:1 molar proportion to yield chlorine‐substituted complexes of the type R2Sn(Schiff base), the base being tridentate. The complexes are characterized on the basis of their elemental analyses, IR and 1H NMR spectral studies. The 13C and 119Sn NMR and the tin‐carbon coupling constant data reveal the structures of the complexes to be octahedral with trans ester grouping, and bidentate ester linkages. The pentacoordinated complex (CH3)2Sn(SBSaD) was prepared by the reaction of dimethyltin oxide with H2SBSaD in equimolar proportions.
Mono‐organotin(IV) compounds as esterification and transesterification catalysts
Authors: Hobbs L A , Smith P J 
Published: December 2004

AbstractA series of monoorganotin(IV) compounds has been investigated as transesterification catalysts for the reaction of butyl propionate with methanol. The most active catalysts were found to be those which contain tin‐halogen bonds, e.g. monobutyltin trichloride (BuSnCl3), and the least effective were the coordinatively saturated monoorganotin derivatives. Certain of the mono(2‐carboalkoxyethyl)tin compounds were found to undergo a facile autocatalysed transesterification reaction with alcohols. Coordination of the carbonyl group in the ester to the tin catalyst is an important factor influencing its activity. A study of the catalysis of the esterification of propionic acid by BuSnCl3 is reported.
Photodissociation of multilayered trimethylaluminum adsorbed on a cryogenic substrate: A time‐of‐flight mass‐spectrometric study
Authors: Kobayashi Makoto , Sato Akihiko , Tanaka Yugo , Shinohara Hisanori , Sato Hiroyasu 
Published: December 2004

AbstractPhotodissociation of trimethylaluminum [Al(CH3)3] adsorbed on a silica (SiO2) substrate at 110 K has been studied by multiphoton ionization time‐of‐flight mass spectrometry. Translational energy distributions of aluminum and AlCH3 fragments can be fitted with a composition of two Maxwell–Boltzmann distributions. The two components are attributed to different environments of photodissociating parent molecules in the multilayer.
High‐Tech‐Folien. Neue Anwendungen für Fluoreszenzfarbstoffe
Authors: Haremza Sylke 
Published: December 2004

AbstractWir alle kommen täglich – bewußt oder unbewußt – mit Gegenständen in Kontakt, bei denen fluoreszierende Verbindungen eingesetzt werden. Dem Bedürfnis nach einem „reinen”︁, strahlenden Weiß wird seit Jahrzehnten durch den Einsatz von optischen Aufhellern, vor allem in Textilien und Papier, Rechnung getragen. Zum gewohnten Alltagsbild zählen Sonderlackierungen von Feuerwehr‐ und Rettungsfahrzeugen ebenso wie Reklamedrucke oder „knallbuntes”︁ Sport‐ und Freizeitequipment vom Surfbrett bis zur Schiedsrichterkarte.
Vielfalt an Ausbildungswegen. Materialwissenschaften – Studium und Arbeitsmarkt
Authors: Thieme Peter 
Published: December 2004

AbstractDer lange Marsch in Richtung Materialwissenschaften begann, als der Mensch lernte, aus Erzen Metalle zu schmelzen und diese durch gezielte Variation seinen Bedürfnissen anzupassen. Ursprünglich ein auf Erfahrung beruhendes Handwerk der Metallgießerei, der Keramikherstellung und der Glasschmelze, sind die Materialwissenschaften inzwischen dank der grundlegenden Erkenntnisse der modernen Chemie und Physik zu einer eigenständigen Forschungsrichtung geworden. Wie sollten die Universitäten auf diese Entwicklung reagieren und welche Perspektiven haben Absolventen mit einer Ausbildung in dieser Fachrichtung auf dem Arbeitsmarkt?
Wissenschaft aktuell
Authors: Janenika Lother 
Published: December 2004

AbstractDie Verwunderung, daß ein gasförmiges, niedermolekulares „Umweltgift”︁ als Signalvermittler im tierischen Organismus dient, ist bei Medizinern und Biochemikern noch frisch, obgleich es die hundert Jahre alte Erfahrung mit Kranzgefäß‐erweiternden Nitrodrogen endlich auf eine solide Basis stellt.