bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transitions Between Male and Female Heterogamety Caused by Sex-Antagonistic Selection
Authors: van Doorn G Sander , Kirkpatrick Mark 
Published: July 2010

Abstract
Many animal taxa show frequent and rapid transitions between male heterogamety (XY) and female heterogamety (ZW). We develop a model showing how these transitions can be driven by sex-antagonistic selection. Sex-antagonistic selection acting on loci linked to a new sex-determination mutation can cause it to invade, but when acting on loci linked to the ancestral sex-determination gene will inhibit an invasion. The strengths of the consequent indirect selection on the old and new sex-determination loci are mediated by the strengths of sex-antagonistic selection, linkage between the sex-antagonistic and sex-determination genes, and the amount of genetic variation. Sex-antagonistic loci that are tightly linked to a sex-determining gene have a vastly stronger influence on the balance of selection than more distant loci. As a result, changes in linkage, caused, for example, by an inversion that captures a sex-determination mutation and a gene under sex-antagonistic selection, can trigger transitions between XY and ZW systems. Sex-antagonistic alleles can become more strongly associated with pleiotropically dominant sex-determining factors, which may help to explain biases in the rates of transitions between male and female heterogamety. Deleterious recessive mutations completely linked to the ancestral Y chromosome can prevent invasion of a neo-W chromosome or result in a stable equilibrium at which XY and ZW systems segregate simultaneously at two linkage groups.
Bacterial DNA Uptake Sequences Can Accumulate by Molecular Drive Alone
Authors: Maughan H , Wilson L A , Redfield R J 
Published: July 2010

AbstractUptake signal sequences are DNA motifs that promote DNA uptake by competent bacteria in the family Pasteurellaceae and the genus Neisseria. The genomes of these bacteria contain many copies of their canonical uptake sequence (often &gt;100-fold overrepresentation), so the bias of the uptake machinery causes cells to prefer DNA derived from close relatives over DNA from other sources. However, the molecular and evolutionary forces responsible for the abundance of uptake sequences in these genomes are not well understood, and their presence is not easily explained by any of the current models of the evolution of competence. Here we describe use of a computer simulation model to thoroughly evaluate the simplest explanation for uptake sequences, that they accumulate in genomes by a form of molecular drive generated by biased DNA uptake and evolutionarily neutral (i.e., unselected) recombination. In parallel we used an unbiased search algorithm to characterize genomic uptake sequences and DNA uptake assays to refine the Haemophilus influenzae uptake specificity. These analyses showed that biased uptake and neutral recombination are sufficient to drive uptake sequences to high densities, with the spacings, stabilities, and strong consensuses typical of uptake sequences in real genomes. This result greatly simplifies testing of hypotheses about the benefits of DNA uptake, because it explains how genomes could have passively accumulated sequences matching the bias of their uptake machineries.
Pubertal Stage and the Prevalence of Violence and Social/Relational Aggression
Authors: Hemphill Sheryl A. , Kotevski Aneta , Herrenkohl Todd I. , Toumbourou John W. , Carlin John B. , Catalano Richard F. , Patton George C. 
Published: July 2010

OBJECTIVE:
We examined associations between pubertal stage and violent adolescent behavior and social/relational aggression.

METHODS:
The International Youth Development Study comprises statewide representative student samples in grades 5, 7, and 9 (N = 5769) in Washington State and Victoria, Australia, drawn as a 2-stage cluster sample in each state. We used a school-administered, self-report student survey to measure previous-year violent behavior (ie, attacking or beating up another person) and social/relational aggression (excluding peers from the group, threatening to spread lies or rumors), as well as risk and protective factors and pubertal development. Cross-sectional data were analyzed.

RESULTS:
Compared with early puberty, the odds of violent behavior were approximately threefold higher in midpuberty (odds ratio [OR]: 2.87 [95% confidence interval (CI): 1.81–4.55]) and late puberty (OR: 3.79 [95% CI: 2.25–6.39]) after adjustment for demographic factors. For social/relational aggression, there were weaker overall associations after adjustment, but these associations included an interaction between pubertal stage and age, and stronger associations with pubertal stage at younger age were shown (P = .003; midpuberty OR: 1.78 [95% CI: 1.20–2.63]; late puberty OR: 3.00 [95% CI: 1.95–4.63]). Associations between pubertal stage and violent behavior and social/relational aggression remained after the inclusion of social contextual mediators in the analyses.

CONCLUSIONS:
Pubertal stage was associated with higher rates of violent behavior and social/relational aggression, with the latter association seen only at younger ages. Puberty is an important phase at which to implement prevention programs to reduce adolescent violent and antisocial behaviors.
Assessing Length-Related Bias and the Need for Data Standardization in the Development of Standard Weight Equations
Authors: Ranney Steven H. , Fincel Mark J. , Wuellner Melissa R. , VanDeHey Justin A. , Brown Michael L. 
Published: July 2010

Abstract
The recently developed empirical percentile (EmP) method, a technique for deriving standard weight (Ws) equations, putatively reduces the length-related biases that often plague such equations. To determine whether the EmP method is superior to the regression line–percentile (RLP) method in reducing length-related biases, we developed new Ws equations by applying both methods to two morphologically distinct species, walleye Sander vitreus and black crappie Pomoxis nigromaculatus. We also investigated diagnostic approaches to provide quality control for weight–length data. We evaluated the new Ws equations with filtered independent data to determine which equation reduced length bias the most. We suggest a protocol for evaluating length-related bias using an independent data set. Our results showed that for randomly selected walleye populations, the RLP method did not have any length-related biases when relative weight (Wr) was plotted as a function of length. However, the Wr values calculated from the EmP Ws equations were length biased when the latter were applied to those same populations. Both methods generated Ws equations that were length biased when Wr was plotted as a function of length for black crappies. Further, the absolute difference in Wr between the RLP and EmP methods indicates that there is little difference between the methods as far as their relevance to management is concerned. Based on these results, we believe that revising existing Ws equations using the EmP method is unnecessary and that the RLP technique should remain the standard for developing Ws equations pending the development of an approach that clearly eliminates methodological length bias.
Evidence of Panmixia between Sympatric Life History Forms of Coastal Cutthroat Trout in Two Lower Columbia River Tributaries
Authors: Johnson Jeffrey R. , Baumsteiger Jason , Zydlewski Joseph , Hudson J. Michael , Ardren William 
Published: July 2010

Abstract
Coastal cutthroat trout Oncorhynchus clarkii clarkii exhibit resident and migratory life history strategies that often occur sympatrically, but the relationship between these forms within a population is poorly characterized. Through use of passive integrated transponder technology, migratory and resident coastal cutthroat trout were identified in two lower Columbia River tributaries (Abernathy Creek and the Chinook River) separated by more than 80 km. Genetic data from 17 highly variable microsatellite loci were used to ascertain the genetic population structure of these life history forms within and between streams. No distinct genetic separation was observed between the life history forms within a stream, as assessed by four different statistical approaches: permutation tests based on the genetic differentiation index FST, principal components analysis of individuals, analysis of molecular variance, and contingency tests of allele frequency heterogeneity. Genetic differences were an order of magnitude higher between stream samples (FST &gt; 0.03) than between life history forms within a stream (FST &lt; 0.003). The contingency test detected allele frequency differences between migratory and resident life history forms in Abernathy Creek (P = 0.001), but this result was influenced more by age-class structure than by reproductive isolation between life history forms. Results are consistent with a single, randomly mating population in each stream producing both migratory and resident life history forms. These data suggest that individual life history strategy in coastal cutthroat trout is predominantly determined by phenotypic plasticity rather than genotype.
The Native Range of Walleyes in the Missouri River Drainage
Authors: Hoagstrom C. W. , Berry C. R. 
Published: July 2010

Abstract
The southern limit of the native range of walleye Sander vitreus is difficult to determine because of sparse historical information, early stockings, and early human disturbances. The southwestern limit is traditionally set within the Missouri River drainage, but the exact limit is uncertain and investigators have recently postulated that walleyes are not native anywhere in the drainage. We conducted a literature review to assess this controversy. The walleye is invasive, it has been stocked into the drainage, and many populations are associated with human-effected habitats (e.g., reservoirs). However, distributional, fossil, and molecular data indicate that walleyes were widespread in the drainage during glacial periods, and there is little evidence that the habitats of the Missouri River drainage are unsuitable. Although the historical information is inconclusive, other fishes with similar histories are regarded as native in at least some of the waters of the drainage. Fish distributions in the Missouri River drainage are dynamic and responsive to climatic fluctuations and human disturbance. The walleye probably is most appropriately considered a marginal native of this basin. Populations should be individually designated native or nonnative based on the following criteria: (1) the population does (does not) inhabit waters accessible via natural dispersal given no anthropogenic barriers (i.e., potential native range), (2) natural habitat conditions would (would not) be suitable (i.e., present native range), and (3) the population does (does not) originate from a native source. These criteria could be applied to all associated fishes for increased consistency among designations.
Sportfishing Participation on Lake Ontario: Modeling the Past, Predicting the Future
Authors: Connelly Nancy A. , Brown Tommy L. 
Published: July 2010

Abstract
Lake Ontario, one of the five Great Lakes bordering the United States and Canada, has a long, rich tradition of sportfishing. The lake provides a good case study showing how biological, societal, and managerial factors interact with each other to affect fishing participation. Fishing effort at Lake Ontario peaked in 1990 and has since trended downward. Using multiple-regression analysis, we found three variables that explain the number of fishing boat trips taken on Lake Ontario over time. The first variable, time, may be acting as a surrogate for two interacting phenomena: the novelty of Great Lakes salmonid fishing specifically, which appears to be gradually declining, and the declining interest in fishing and outdoor recreation seen nationally. Stakeholders may look first for local explanations for changes, but they need to consider that national and societal trends may be very important. Second, a biological variable, the number of Pacific salmon Oncorhynchus spp. stocked in Lake Ontario, is positively correlated with boat trips. Third, the number of black bass Micropterus spp. harvested is positively correlated with the number of trips. Although not significant at the cutoff level of 0.05, this variable was retained in the model because it was considered an important variable and was close to the cutoff at 0.074. Forecasting these variables into the future, the model predicts a decline of 32% in fishing trips in the ensuing 5 years. Armed with this information, local communities can choose to be proactive and try to counteract the trend predicted by the model. The use of case studies and regression analysis to explain and forecast trends may be applicable to many other fisheries situations across the country.
Comparison of Two Alternative Approaches for Estimating Dam Passage Survival of Salmon Smolts
Authors: Skalski John R. , Townsend Richard L. , Steig Tracey W. , Hemstrom Steven 
Published: July 2010

Abstract
Traditional single and paired release–recapture models are incapable of providing unbiased estimates of dam passage survival because their assumptions can never be met. Nevertheless, regulatory requirements mandate the estimation of this important performance measure for migratory fish species passing through hydroprojects. We present a new release–recapture model that uses a virtual release of in-river migrants known to have arrived at the dam, combined with a paired release below the dam, to estimate dam passage survival. Analytical comparisons of the sampling precision of the proposed virtual–paired-release model and an established route-specific model found that the new approach was always more precise for equal release numbers of tagged fish. In a field trial at Rocky Reach Dam, Washington, using smolts of sockeye salmon Oncorhynchus nerka, the new approach estimated dam passage survival with more than twice the precision of the alternative method. The proposed virtual–paired-release design has the potential to provide robust and precise estimates of dam passage survival under a variety of hydroproject scenarios.
Physical Injuries in Juvenile Atlantic Salmon, Slimy Sculpin, and Blacknose Dace Attributable to Electrofishing
Authors: Clément Marie , Cunjak Richard A. 
Published: July 2010

Abstract
Juvenile Atlantic salmon Salmo salar captured by electrofishing were X-rayed and dissected to determine rates of electrofishing-induced spinal injuries and hemorrhages. This study showed a low incidence of spinal injuries (11%) in electrofished wild parr captured alive and thereafter sacrificed. A negligible hemorrhage rate (2%) was observed. All of the spinal injuries observed were rated class 1 (minor injury), except for a class 2 injury in one parr. Larger, older wild parr (≥age 2) showed a higher incidence of spinal injuries (17%) than age-1 parr (4%). Parr captured with two or more electrofishing sweeps had a spinal injury rate of 20%, compared with 6% when captured with a single electrofishing sweep. Among the mortalities, 8% of the parr had spinal injuries (class 1 except for one class 3) and 5% had hemorrhages. Spinal injury was observed in 6% of the mortalities of slimy sculpin Cottus cognatus and blacknose dace Rhinichthys atratulus; no hemorrhages were observed in these fish. This study showed that electrofishing produced a low incidence of injuries in juvenile Atlantic salmon, slimy sculpin, and blacknose dace. Nonetheless, caution is advised when conducting electrofishing surveys because sublethal effects other than physical injuries remain largely unknown.
Did the Texas Closure Increase Brown Shrimp Catches off Texas?
Authors: Matlock Gary C. 
Published: July 2010

Abstract
The annual catch of brown shrimp Farfantepenaeus aztecus off Texas is forecasted by the National Marine Fisheries Service using a model that relates spring (April–June) juvenile abundance in Galveston Bay to subsequent offshore catch (July to the following June). The model is not well documented, nor has it been used rigorously to examine the success of management actions in enhancing the fishery. State and federal agencies use an areal closure of Gulf of Mexico waters deeper than 4 fathoms from late May to early July to increase shrimp abundance, catch, and value by delaying the harvest of emigrating juvenile shrimp. This study reports a preclosure (1960–1980) regression that explained over 70% of the variation in offshore Texas catches as a function of the juvenile abundance index from Galveston Bay. Positive effects of the closure—in terms of increasing the catch for a given level of juvenile abundance in 1981–2007—were not found in this study. However, the utility of the relationship between the juvenile abundance index and catch as a forecasting tool continued through 2007, but with less precision than in the preclosure regression.
Recall Bias in a Sportfishing Mail Survey
Authors: Osborn Maury F. , Matlock Gary C. 
Published: July 2010

Abstract
Information on sportfishing activity is often collected through mail and telephone surveys. These surveys may rely on a respondent's memories of a previous year's activity, which are subject to recall errors. Limited research has been conducted to quantify the possible bias caused by recall periods less than 1 year. Data from a 1982 mail survey of registered Texas boat owners were used to determine whether estimated saltwater sport boat fishing effort differed based on recall periods of 1 month and 1 year. The mean annual number of days of saltwater fishing per registered boat owner was statistically similar for the two recall periods although variances were statistically different. However, the number of days of saltwater fishing was about 7.5 times higher for coastal county residents than for inland county residents. The pattern of use among boat access types and fishing areas was generally similar between coastal and inland county residents within each recall period. However, the estimated number of days each access type was used and the reported number of days each area was fished were significantly different between the two recall periods. Saltwater fishing participation estimates based on a 1-year recall could be adjusted using the relationship between the two recall periods to improve accuracy and precision of estimates and to reduce sampling costs. Fisheries managers could more effectively monitor changes in fishing activity for possible development of forecasting models.
Behavior and Breeding Success of Wild and First‐Generation Hatchery Male Spring Chinook Salmon Spawning in an Artificial Stream
Authors: Schroder Steven L. , Knudsen Curtis M. , Pearsons Todd N. , Kassler Todd W. , Young Sewall F. , Beall Edward P. , Fast David E. 
Published: July 2010

AbstractSpring Chinook salmon Oncorhynchus tshawytscha native to the upper Yakima River, Washington, were placed into an artificial stream to evaluate the effect of a single generation of hatchery culture on their spawning behavior and ability to produce offspring. From 2001 to 2005, seven independent test groups containing wild and hatchery fish were placed into the stream. The effects of body weight, spawning ground longevity, attack frequency, social dominance, courting frequency, and mate number on breeding success in hatchery and wild males were evaluated. Male breeding success increased with body weight, while spawning ground longevity was negatively associated with breeding success. Although important, body weight had a lesser effect on male breeding success than did social dominance or attack frequency. Males with high attack and courting frequencies produced the most progeny; of the traits examined, the number of female spawning partners explained the greatest amount of variation (average r2 = 80%) in male breeding success. Differences in male agonism due to male origin were found. Wild males exhibited higher attack rates and greater social dominance than did hatchery males. However, the observed inequalities in agonism and dominance appeared to be largely caused by differences in body weight between the two types of males: wild males were, on average, 9% heavier than hatchery males. Wild and hatchery males did not differ in the frequency of courting behaviors or in the number of mates. Pedigree analyses based on DNA showed that hatchery and wild males had comparable breeding success values. Consequently, a single generation of hatchery exposure appeared to have a low effect on spring Chinook salmon male breeding success in our experimental setting.
Habitat Selection and Abundance of Young‐of‐Year Smallmouth Bass in North Temperate Lakes
Authors: Brown Peter James , Bozek Michael Anthony 
Published: July 2010

AbstractHabitat use during early life history plays an important role in the ecology of smallmouth bass Micropterus dolomieu in north temperate lakes. The highest levels of mortality occur during the first year of life, and the habitat selected probably affects mortality. We used resource selection functions and abundance data from two northern Wisconsin lakes to determine the habitats that influence the survival of smallmouth bass. Coarse substrates were consistently important to both nesting locations and young‐of‐year smallmouth bass. Young smallmouth bass used woody structure after swimming from their nests but disassociated themselves from habitats with more complex woody structure by August. Nonwoody cobble areas offer protection for young‐of‐year smallmouth bass without attracting predators, as woody habitats do. The decline in the abundance of young‐of‐year smallmouth bass was best fit to an exponential decay function in woody habitats, but in rock habitats it was linear. Habitat selection by young‐of‐year smallmouth bass shifts over time, and the shift is linked to predation risk: woody habitats initially offer them an advantage with respect to spawning but eventually provide their predators greater opportunities for ambush. This shift underscores the importance of having a diversity of littoral habitats. This study provides the first quantifiable analyses describing the habitat features selected by young‐of‐year smallmouth bass and links these descriptions to population dynamics.
Timing of Walleye Spawning as an Indicator of Climate Change
Authors: Schneider Kristal N. , Newman Raymond M. , Card Virginia , Weisberg Sanford , Pereira Donald L. 
Published: July 2010

AbstractWe obtained Minnesota Department of Natural Resources historical records describing the egg‐take from walleyes Sander vitreus at 12 spawning locations to determine whether the timing of walleye spawning runs could be used as an indicator of climate change. We used ice‐out data instead of temperature for our analyses because walleyes often spawn soon after ice‐out, and ice‐out has been previously related to climate change. We used linear regressions to determine (1) the relationship between the start of spawning (based on first egg‐take) or peak of the spawning run (greatest egg‐take) and ice‐out date and (2) whether long‐term trends existed in ice‐out and date of spawning over time. Linear regressions of the date of first walleye egg‐take versus ice‐out date showed that walleye spawning begins 0.5–1.0 d earlier for each 1.0‐d decrease in ice‐out date. All but two regressions had slopes less than 1.0. Similar results were found for peak of spawning runs. Regressions of egg‐take and ice‐out date versus year showed trends toward both earlier spawning and earlier ice‐out. For regressions of first egg‐take versus year (16 total with restricted data sets), significant negative slopes (P < 0.10) were observed in 5 of 16 regressions; for peak egg‐take, six regressions had significant negative slopes. For regressions of ice‐out date versus year, 25 of 26 regressions were negative; there were nine significant negative slopes (P < 0.10). Overall, ice‐out and walleye spawning are occurring earlier in Minnesota, and the timing of walleye spawning may be a good biological indicator of climate change.