bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-Density Linkage Maps and Sex-Linked Markers for the Black Tiger Shrimp (Penaeus monodon)
Authors: Staelens Jan , Rombaut Debbie , Vercauteren Ilse , Argue Brad , Benzie John , Vuylsteke Marnik 
Published: June 2008

Abstract
We report on the construction of sex-specific high-density linkage maps and identification of sex-linked markers for the black tiger shrimp (Penaeus monodon). Overall, we identified 44 male and 43 female linkage groups (2n = 88) from the analysis of 2306 AFLP markers segregating in three full-sib families, covering 2378 and 2362 cM, respectively. Twenty-one putatively homologous linkage groups, including the sex-linkage groups, were identified between the female and male linkage maps. Six sex-linked AFLP marker alleles were inherited from female parents in the three families, suggesting that the P. monodon adopts a WZ–ZZ sex-determining system. Two sex-linked AFLP markers, one of which we converted into an allele-specific assay, confirmed their association with sex in a panel of 52 genetically unrelated animals.
Efficient Markov Chain Monte Carlo Implementation of Bayesian Analysis of Additive and Dominance Genetic Variances in Noninbred Pedigrees
Authors: Waldmann Patrik , Hallander Jon , Hoti Fabian , Sillanpää Mikko J 
Published: June 2008

AbstractAccurate and fast computation of quantitative genetic variance parameters is of great importance in both natural and breeding populations. For experimental designs with complex relationship structures it can be important to include both additive and dominance variance components in the statistical model. In this study, we introduce a Bayesian Gibbs sampling approach for estimation of additive and dominance genetic variances in the traditional infinitesimal model. The method can handle general pedigrees without inbreeding. To optimize between computational time and good mixing of the Markov chain Monte Carlo (MCMC) chains, we used a hybrid Gibbs sampler that combines a single site and a blocked Gibbs sampler. The speed of the hybrid sampler and the mixing of the single-site sampler were further improved by the use of pretransformed variables. Two traits (height and trunk diameter) from a previously published diallel progeny test of Scots pine (Pinus sylvestris L.) and two large simulated data sets with different levels of dominance variance were analyzed. We also performed Bayesian model comparison on the basis of the posterior predictive loss approach. Results showed that models with both additive and dominance components had the best fit for both height and diameter and for the simulated data with high dominance. For the simulated data with low dominance, we needed an informative prior to avoid the dominance variance component becoming overestimated. The narrow-sense heritability estimates in the Scots pine data were lower compared to the earlier results, which is not surprising because the level of dominance variance was rather high, especially for diameter. In general, the hybrid sampler was considerably faster than the blocked sampler and displayed better mixing properties than the single-site sampler.
Extraordinary Tertiary Constrictions of Tripsacum dactyloides Chromosomes: Implications for Karyotype Evolution of Polyploids Driven by Segmental Chromosome Losses
Authors: Koo Dal-Hoe , Jiang Jiming 
Published: June 2008

Abstract
Tripsacum dactyloides (2n = 2x = 36) is an ancient tetraploid species. Here we report that T. dactyloides chromosomes contain an extraordinary tertiary constriction, which causes a radical and distant separation of a terminal segment from the chromosome. The relationships between extraordinary tertiary constriction and segmental chromosome loss as well as karyotype evolution of polyploid species are discussed.
Using Directional Feeders to Feed Juvenile Coho Salmon in an Attempt to Increase Adult Survivals
Authors: Tipping Jack M 
Published: June 2008

Abstract
This study compared adult survivals of juvenile coho salmon Oncorhynchus kisutch fed with nonmoving directional feeders with fish fed by hand. In each of 2 years, two net-pens each of coded-wire-tagged coho salmon juveniles were fed with either directional feeders or by hand from January until release in May–June. Adult return rates were compared using analysis of variance, and no significant difference in fish survival was detected between the two feeding methods; mean recoveries were 2.43% and 2.45% for directional-feeder and hand-fed fish, respectively. However, directional feeders could provide labor savings if water-feed fouling were avoided.
Linking Landscapes and Habitat Suitability Scores for Diadromous Fish Restoration in the Susquehanna River Basin
Authors: Kocovsky Patrick M. , Ross Robert M. , Dropkin David S. , Campbell John M. 
Published: June 2008

Abstract
Dams within the Susquehanna River drainage, Pennsylvania, are potential barriers to migration of diadromous fishes, and many are under consideration for removal to facilitate fish passage. To provide useful input for prioritizing dam removal, we examined relations between landscape-scale factors and habitat suitability indices (HSIs) for native diadromous species of the Susquehanna River. We used two different methods (U.S. Fish and Wildlife Service method: Stier and Crance (1985), Ross et al. (1993a, 1993b, 1997), and Pardue (1983); Pennsylvania State University method: Carline et al. (1994)) to calculate HSIs for several life stages of American shad Alosa sapidissima, alewives Alosa pseudoharengus, and blueback herring Alosa aestivalis and a single HSI for American eels Anguilla rostrata based on habitat variables measured at transects spaced every 5 km on six major Susquehanna River tributaries. Using geographical information systems, we calculated land use and geologic variables upstream from each transect and associated those data with HSIs calculated at each transect. We then performed canonical correlation analysis to determine how HSIs were linked to geologic and land use factors. Canonical correlation analysis identified the proportion of watershed underlain by carbonate rock as a positive correlate of HSIs for all species and life stages except American eels and juvenile blueback herring. We hypothesize that potential mechanisms linking carbonate rock to habitat suitability include increased productivity and buffering capacity. No other consistent patterns of positive or negative correlation between landscape-scale factors and HSIs were evident. This analysis will be useful for prioritizing removal of dams in the Susquehanna River drainage, because it provides a broad perspective on relationships between habitat suitability for diadromous fishes and easily measured landscape factors. This approach can be applied elsewhere to elucidate relationships between fine- and coarse-scale variables and suitability of habitat for fishes.
Positive Effects of Agricultural Land Use Changes on Coldwater Fish Communities in Southwest Wisconsin Streams
Authors: Marshall David W. , Fayram Andrew H. , Panuska John C. , Baumann James , Hennessy Joseph 
Published: June 2008

Abstract
The Conservation Reserve Program (CRP) is a federal program that encourages the planting of cool- or warm-season grass cover on highly erodible croplands and along stream corridors. We sought to determine whether fish community structure in coldwater streams was associated with CRP and other agricultural land use changes in southwestern Wisconsin. We compared coldwater fish index of biotic integrity (IBI) scores and species richness in streams located in areas of relatively high (21.3% of land area; high-CRP area) versus relatively low (12.1% of land area; low-CRP area) CRP participation. All of the streams were sampled in the 1970s before implementation of the CRP and again at the same locations after implementation, from 2000 to 2005. Pre-CRP fish communities were characterized by a relatively high diversity of eurythermal species and low coldwater IBI scores. We found significant increases in coldwater IBI scores over time in streams within the high-CRP area relative to streams within the low-CRP area. Fish populations in streams within the high-CRP area shifted from eurythermal and tolerant species before CRP implementation to stenothermal, cool- and coldwater species after implementation. Ecological responses within the high-CRP streams also included a reduction in species richness. Without intensive monitoring of watershed nutrients, the fish community changes cannot be mechanistically linked to specific land use practices. However, we demonstrate that IBI scores and species richness were correlated with phosphorus loading estimates and that predicted phosphorus reductions were greater within the high-CRP grassland area. The estimated phosphorus loading declines reflected reduced cropland areas and reduced density of dairy farms. The estimates did not capture all environmental factors, such as trends in production of hogs and cattle or streamflow regime changes associated with conservation practices. We conclude that the combination of extensive grassland management, livestock reductions, and other long-term agricultural land use changes benefited the coldwater fish communities within the high-CRP area.
The Application of Rapid Microsatellite-Based Stock Identification to Management of a Chinook Salmon Troll Fishery off the Queen Charlotte Islands, British Columbia
Authors: Beacham Terry D. , Winther Ivan , Jonsen Kimberly L. , Wetklo Michael , Deng Langtuo , Candy John R. 
Published: June 2008

Abstract
Since 1995, the Northern British Columbia (NBC) troll fishery has been managed to reduce exploitation on stocks of Chinook salmon Oncorhynchus tshawytscha from the West Coast of Vancouver Island (WCVI). Before 2002, management actions in the NBC troll fishery were generally large-scale quota reductions and area closures that resulted in substantially reduced catches of Chinook salmon relative to the existing quota. Since 2002, in-season microsatellite-based stock identification has been used to address WCVI Chinook salmon management in the NBC troll fishery. The change in management strategy has resulted in increased quota utilization and increased catches of approximately 390,000 fish during 2002–2005. The increased catch in the fishery was concurrent with average fishing mortality on the main WCVI hatchery indicator stock declining from an average 3.3% during the era of reduced catches (1995–2001) to 2.3% since 2002, when in-season, microsatellite-based stock identification was applied to guide the locations and timing of NBC troll fishery openings.
Global Review of the Physical and Biological Effectiveness of Stream Habitat Rehabilitation Techniques
Authors: Roni Phil , Hanson Karrie , Beechie Tim 
Published: June 2008

Abstract
The degradation of inland aquatic habitats caused by decades of human activities has led to worldwide efforts to rehabilitate freshwater habitats for fisheries and aquatic resources. We reviewed published evaluations of stream rehabilitation techniques from throughout the world, including studies on road improvement, riparian rehabilitation, floodplain connectivity and rehabilitation, instream habitat improvement, nutrient addition, and other, less-common techniques. We summarize current knowledge about the effectiveness of these techniques for improving physical habitat and water quality and increasing fish and biotic production. Despite locating 345 studies on effectiveness of stream rehabilitation, firm conclusions about many specific techniques were difficult to make because of the limited information provided on physical habitat, water quality, and biota and because of the short duration and limited scope of most published evaluations. Reconnection of isolated habitats, floodplain rehabilitation, and instream habitat improvement have, however, proven effective for improving habitat and increasing local fish abundance under many circumstances. Techniques such as riparian rehabilitation, road improvements (sediment reduction), dam removal, and restoration of natural flood regimes have shown promise for restoring natural processes that create and maintain habitats, but no long-term studies documenting their success have yet been published. Our review demonstrates that the failure of many rehabilitation projects to achieve objectives is attributable to inadequate assessment of historic conditions and factors limiting biotic production; poor understanding of watershed-scale processes that influence localized projects; and monitoring at inappropriate spatial and temporal scales. We suggest an interim approach to sequencing rehabilitation projects that partially addresses these needs through protecting high-quality habitats and restoring connectivity and watershed processes before implementing instream habitat improvement projects.
Classification Tree Models for Predicting Distributions of Michigan Stream Fish from Landscape Variables
Authors: Steen Paul J. , Zorn Troy G. , Seelbach Paul W. , Schaeffer Jeffrey S. 
Published: June 2008

AbstractTraditionally, fish habitat requirements have been described from local‐scale environmental variables. However, recent studies have shown that studying landscape‐scale processes improves our understanding of what drives species assemblages and distribution patterns across the landscape. Our goal was to learn more about constraints on the distribution of Michigan stream fish by examining landscape‐scale habitat variables. We used classification trees and landscape‐scale habitat variables to create and validate presence‐absence models and relative abundance models for Michigan stream fishes. We developed 93 presence‐absence models that on average were 72% correct in making predictions for an independent data set, and we developed 46 relative abundance models that were 76% correct in making predictions for independent data. The models were used to create statewide predictive distribution and abundance maps that have the potential to be used for a variety of conservation and scientific purposes.
Chemical Recovery of Gas Hydrates Using Fluorine Gas and Microwave Technology
Authors: Garg Rachit , Ogra Konark , Choudhary Arpit , Menezes Richard 
Published: June 2008

Abstract
Methane gas hydrates are cages of water molecule that trap small, low molecular weight gas molecules e.g. methane, ethane, hydrogen sulfide etc. the enormous quantity of gas stored in them (1m3 G.H = 180m3) makes them an important area of research for the scientist and petroleum engineers.
Over the years the various theoretical techniques for recovery of the gas hydrates are Lthermal injection 2.inhibitors 3.depressurization. However due to inefficient and economic unfeasibility it is difficult to recover the methane from gas hydrates.
Low injectivity reservoir, small thickness of G.H bearing zone, heat loss especially in permafrost region, also the cost of the inhibitors (which change the thermodynamic condition) is litre of methanol makes it uneconomical, finally depressurization of an adjacent free gas zone can effectively dissociate hydrate but the endothermic nature of the hydrate decomposition will decrease the reservoir temperature and which may temporarily decrease the flow rate. The technical problems with estimating the gas hydrate are
Technology to safely and economically produce methane from G.H deposits. Safety and drill floor stability related issues related to drilling through G.H bearing accumulations.
This paper deals with a new technique of a recovery of methane from G.H.This technique involves use of a micro strip antenna which has huge power gain and is relatively inexpensive, with wire line the tool is placed in well bore and frequency of 2450 MHz is released which melt the G.H into water and methyl radical (as they are almost similar to ice) such that they disturb the thermodynamic condition, then the fluorine is injected, this results in reaction between methyl radical and injected fluorine (halogenation), which is strongly exothermic (-431KJ/mole), this reaction propagates the reaction and simultaneously we have solubility of methyl fluoride with water which is 166cc/ 100 ml of water. This pressurized gas solution is then recovered via tubing from production well. Later by applying wurtz reaction, electrolysis and cracking methane can be recovered.
The main advantage of using this technique is micro waves interact strongly with some materials and weakly with others, energy absorption depends on microwave frequency, sample composition, temperature. The chemical compound fluorine is abundant in nature (540000ppb) and methyl fluoride is environmental friendly.
In this technique, the pressure of the fluids in contact with hydrate is lowered, pushing the hydrate out of its stability region and leading to its decomposition. Because no extra heat is introduced into the reservoir, the heat of decomposition must be supplied from the surrounding formation.
Evaluation of Rigless Water Shutoff Treatments to be Used in Arab-C Carbonate Reservoir in Saudi Arabia
Authors: Al-Dhafeeri A. M. , Nasr-El-Din H. A. , Al-Harith A. M. 
Published: June 2008

Abstract
A multi-lateral oil-producing well A was killed due to excessive water production from Arab-C that is dumping into the Arab-D reservoir. Therefore, the communication between Arab-C and Arab-D where behind the expandable liner is urgently needed to be blocked. Several solutions were investigated in an attempt to stop this flow behind casing. This problem is always a challenging task for field operators. The effect of excess water production on the productive zone, Arab-D reservoir will be substantial in terms of changes in relative permeability of this zone and increased water saturation. This change in the reservoir behavior will result in reduction of well life.
The dead well A is a valuable asset that needs to be effectively utilized throughout the producing life of the field. Therefore, remedial treatments to revive this well are of value in terms of strategic plan to maximize revenues. Although the rigless water conformance method in a multi-lateral oil-producing well is a difficult task to the oil companies because of reservoir heterogeneity, cross-flow, gel placement, and cost.
Several options of water shutoff treatment are proposed to address remedial treatments for water conformance problems. The main objective of this study is to: 1) Identify and characterize the source of produced water, 2) Identify the chemical blocking agents that will flow through the water out zone, and 3) identify an effective technique to optimize the size and the placement of these chemicals. Challenges, design criteria, and field treatment evaluation are addressed in this paper.
A Simple and Accurate Mathematical Model for Predicting Productivity of Multifractured Horizontal Wells
Authors: Guo Boyun , Yu Xiance 
Published: June 2008

Abstract
Horizontal wells drilled in the direction of the minimum horizontal stress allow for multiple transverse fractures be hydraulically created for enhancing well productivity in low-permeability oil and gas reservoirs. Dominating factors affecting the productivity of the multi-fractured horizontal wells vary with reservoir and fracture properties, as well as well trajectories. A simple and accurate mathematical model for evaluating and optimizing productivity of this type of wells is not available and is highly desirable to reservoir engineers. This paper fills the gap.
After a case study with existing analytical models that were derived for multi-fractured wells we found that these models cannot describe the performance of oil wells with acceptable accuracy. We then formulated a simple analytical model that better describes the productivity of multi-fractured horizontal wells. The new model couples the radial flow in the non-fractured region of reservoir, the linear flow toward the fractures in the fractured region, the linear flow in the fracture, and the radial flow in the fracture toward the horizontal wellbore. It can model pseudo-steady state flow of reservoir fluids in sections reservoir of any shape with the fractured region being located at any area in the reservoir. The difference between the production rate given by the new model and the actual production rates was found to be less than 5% in the two cases studied. This paper provides reservoir engineers a simple and accurate tool for predicting, evaluating, and optimizing the performance of multi-fractured horizontal oil and gas wells.
Effect of Oilfield Scale Deposition on Mobility Ratio
Authors: Fadairo A. S. , Omole O. , Falode O. A. 
Published: June 2008

Abstract
Scaling phenomenon is a major problem that occurs when water is injected for oil displacement and pressure maintenance in oilfields. This phenomenon of precipitation and accumulation of oilfield scale due to incompatibility between formation and injected water is induced around the well bore after water breakthrough at reduced reservoir pressure. The effect results in formation damage which may negatively impact on reservoir performance well bore performance and the success of water flooding project that depends on mobility ratio. This paper presents an analytical model based on existing thermodynamic models for predicting brine mobility, hydrocarbon mobility and mobility ratio of water flooded reservoir with possible incidence of scale precipitation and accumulation. The key operational and reservoir/brine parameters which influence the mobility ratio such as salt concentration in the brine, produced water rate, pressure drawdown, reservoir temperature were identified using this model.
Results of the study shows that the mobility ratio of a water flooded reservoir remains constant until water breakthrough and achieves an increasing local maximum at 10% pore volume injected water as the flow rate of produced water increases with a significant jump beyond the critical flow rate observed at mobility ratio of 1. Similar results corroborating above were obtained with variation in skin factor.
This model therefore can be used to diagnose, evaluate and simulate mobility ratio and skin factor in a water flood scheme enabling production engineers plan an economically efficient water flood scheme.