bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of the SNAT2 amino acid transporter during the development of rat cerebral cortex
Authors: Angelina Rodríguez , Laura C Berumen , Francisco Zafra , Cecilio Giménez , Guadalupe García‐Alcocer María 
Published: June 2011

AbstractThe sodium‐coupled neutral amino acid transporter 2 (SNAT2) is a protein that is expressed ubiquitously in mammalian tissues and that displays Na+, voltage and pH dependent activity. This transporter mediates the passage of small zwitterionic amino acids across the cell membrane and regulates the cell homeostasis and its volume. We have examined the expression of SNAT2 mRNA and protein during the development of the rat cerebral cortex, from gestation through the postnatal stages to adulthood. Our data reveal that SNAT2 mRNA and protein expression is higher during embryogenesis, while it subsequently diminishes during postnatal development. Moreover, during embryonic period SNAT2 colocalizes with the radial glial cells marker GLAST, while in postnatal period it is mainly detected in neuronal dendrites. These findings suggest a relevant role for amino acid transport through SNAT2 in the developing embryonic brain.
The role of faith‐based organizations in maternal and newborn health care in Africa
Authors: Widmer Mariana , Betran Ana P. , Merialdi Mario , Requejo Jennifer , Karpf Ted 
Published: June 2011

AbstractBackgroundGlobal disparities in maternal and newborn health represent one of the starkest health inequities of our times. Faith‐based organizations (FBOs) have historically played an important role in providing maternal/newborn health services in African countries. However, the contribution of FBOs in service delivery is insufficiently recognized and mapped.ObjectivesA systematic review of the literature to assess available evidence on the role of FBOs in the area of maternal/newborn health care in Africa.Search strategyMEDLINE and EMBASE were searched for articles published between 1989 and 2009 on maternal/newborn health and FBOs in Africa.ResultsSix articles met the criteria for inclusion. These articles provided information on 6 different African countries. Maternal/newborn health services provided by FBOs were similar to those offered by governments, but the quality of care received and the satisfaction were reported to be better.ConclusionEfforts to document and analyze the contribution of FBOs in maternal/newborn health are necessary to increase the recognition of FBOs and to establish stronger partnerships with them in Africa as an untapped route to achieving Millennium Development Goals 4 and 5.
The influence of exchange hazards and power on opportunism in outsourcing relationships
Authors: Handley Sean M. , Benton W.C. 
Published: June 2011

AbstractService provider opportunism is widely noted as a principal risk with outsourcing. Indeed, economic theory regarding the factors which influence the outsourcing decision, treats opportunism as a core behavioral assumption. It is assumed that if given the opportunity, outsourcing providers will act in a self‐serving manner despite the potentially negative impact it may have on their customer. Other researchers have suggested that opportunism is not an unwavering human behavior, but rather can be substantively influenced by the management practices which define the relationship. Building on these arguments, this study investigates the validity of these divergent positions. Hierarchical linear regression is used to examine dyadic data on 102 information technology, logistics, and other business process outsourcing relationships. We test a model which hypothesizes that the buying firm's reliance on different bases of inter‐firm power will have differing effects on the risk of opportunism (shirking and poaching). These hypotheses are evaluated while concurrently examining the influence of exchange hazards (relationship‐specific investments and technological uncertainty) on provider shirking and poaching. The results offer strong evidence that buyer reliance on mediated forms of power (i.e. rewards, coercive, legal legitimate) enhance the risk of both provider shirking and poaching, while non‐mediated power (i.e. expert, referent) is associated with a diminished level of opportunistic behavior. Interestingly, relationship‐specific investments have a significant effect on some forms of opportunistic behavior but not on other forms of opportunistic behavior. Technological uncertainty did not have a significant impact on provider opportunism.
Better Catch Curves: Incorporating Age‐Specific Natural Mortality and Logistic Selectivity
Authors: Thorson James T. , Prager Michael H. 
Published: June 2011

AbstractCatch‐curve analysis is one of the simplest methods for stock assessment and is widely applied in data‐poor fisheries. Conventional catch‐curve methods rely on the strong assumptions of constant fishing and natural mortality rates above some fully selected age that is usually estimated by visually inspecting a plot of catch at age. Here, we evaluate the performance of three catch‐curve methods that relax or modify these assumptions by (1) estimating logistic selectivity parameters, (2) assuming Lorenzen‐form natural mortality (natural mortality that decreases with weight), and (3) using both methods simultaneously. We used simulation modeling and decision tables to compare estimates of fishing mortality from four catch‐curve methods, including the conventional method, across a variety of observable and unobservable data characteristics. We then applied the methods to catch‐at‐age data for Atlantic menhadenBrevoortia tyrannusfrom the U.S. South Atlantic fishery management region and compared the resulting estimates with published estimates of fishing mortality (F). In our simulation modeling, catch curves that estimated logistic selectivity parameters performed better than those derived by the conventional method when logistic selectivity was present. There was generally little difference in performance between estimates assuming constant natural mortality and those assuming Lorenzen natural mortality. The improvements from estimating selectivity parameters were particularly pronounced when the sample sizes for catch‐at‐age data were large: in those instances, estimating selectivity improved the estimation accuracy forFby nearly 20%. In our example involving Atlantic menhaden, estimates ofFassuming logistic selectivity were most similar to those of published stock assessments, which had previously estimated logistic selectivity at age. We recommend our logistic‐selectivity catch curve when selectivity is likely to be logistic because it improves accuracy at only a very small cost in terms of computational complexity.
Increasing Regional Temperatures Associated with Delays in Atlantic Salmon Sea‐Run Timing at the Southern Edge of the European Distribution
Authors: Valiente A. G. , Juanes F. , Garcia‐Vazquez E. 
Published: June 2011

AbstractPopulations of Atlantic salmon Salmo salar at the edge of the species’ distribution are the most vulnerable to environmental changes. Those inhabiting southern European rivers are expected to be particularly affected by global warming. However, they are exploited as a very valuable resource for the region, attracting tourism and generating substantial income. In the central part of northern Spain (Asturias), there is a long tradition of sport fisheries (angling). The first salmon caught in a river each year is called the “campanu.” Analysis of a 50‐year time series demonstrates that the run timing of the Asturian Atlantic salmon has changed over this period, as inferred from significant delays in the date of capture of the campanu. Average campanu weight has experienced a parallel significant decrease but age has not changed, indicating diminution of salmon condition. These changes are statistically associated with an increase in regional temperature, there being a minor effect of the global climate North Atlantic Oscillation index. Negative effects of high temperatures on salmon run and feeding, together with long migratory routes, may explain these results.
Determinants of Fish Assemblage Structure in Northwestern Great Plains Streams
Authors: Mullen Jason A. , Bramblett Robert G. , Guy Christopher S. , Zale Alexander V. , Roberts David W. 
Published: June 2011

AbstractPrairie streams are known for their harsh and stochastic physical conditions, and the fish assemblages therein have been shown to be temporally variable. We assessed the spatial and temporal variation in fish assemblage structure in five intermittent, adventitious northwestern Great Plains streams representing a gradient of watershed areas. Fish assemblages and abiotic conditions varied more spatially than temporally. The most important variables explaining fish assemblage structure were longitudinal position and the proportion of fine substrates. The proportion of fine substrates increased proceeding upstream, approaching 100% in all five streams, and species richness declined upstream with increasing fine substrates. High levels of fine substrate in the upper reaches appeared to limit the distribution of obligate lithophilic fish species to reaches further downstream. Species richness and substrates were similar among all five streams at the lowermost and uppermost sites. However, in the middle reaches, species richness increased, the amount of fine substrate decreased, and connectivity increased as watershed area increased. Season and some dimensions of habitat (including thalweg depth, absolute distance to the main‐stem river, and watershed size) were not essential in explaining the variation in fish assemblages. Fish species richness varied more temporally than overall fish assemblage structure did because common species were consistently abundant across seasons, whereas rare species were sometimes absent or perhaps not detected by sampling. The similarity in our results among five streams varying in watershed size and those from other studies supports the generalization that spatial variation exceeds temporal variation in the fish assemblages of prairie and warmwater streams. Furthermore, given longitudinal position, substrate, and stream size, general predictions regarding fish assemblage structure and function in prairie streams are possible.
Microsatellite Identification of Canadian Sockeye Salmon Rearing in the Bering Sea
Authors: Beacham Terry D. , Candy John R. , Porszt Erin , Sato Shunpei , Urawa Shigehiko 
Published: June 2011

AbstractThe stock composition of sockeye salmon Oncorhynchus nerka caught in the central Bering Sea in the summer of 2009 was estimated to evaluate migration patterns of salmon of Canadian origin, which have not been demonstrated previously to rear in the Bering Sea. The variation at 14 microsatellites was analyzed for 450 immature sockeye salmon, and a baseline of 387 populations from Japan, Russia, Alaska, Canada, and Washington State was used to determine the stock composition of the fish sampled. Sockeye salmon originating from Alaska were the most abundant in the catch, comprising 86.0% of all sockeye salmon caught, the catch being dominated by sockeye salmon of Bristol Bay origin. Russian‐origin sockeye salmon accounted for 10.2% of the catch, while Canadian‐origin sockeye salmon accounted for 3.8% of the catch. Salmon from Canada were estimated to originate from the Fraser River, Rivers Inlet (Owikeno Lake), the Skeena River (Babine Lake), the Stikine River, and the Alsek River, British Columbia. These results indicate that the central Bering Sea provides a summer rearing area for some Canadian sockeye salmon.
The Response to Forced Decompression in Six Species of Pacific Rockfish
Authors: Pribyl Alena L. , Kent Michael L. , Parker Steven J. , Schreck Carl B. 
Published: June 2011

AbstractPacific rockfish experience high discard mortality when captured owing to a condition called barotrauma, which is caused by the change in pressure during capture. This condition appears to be species specific at the macroscopic level; however, little is known about the microscopic tissue‐level effects of barotrauma. Determining whether tissue‐level injuries are also species specific or influenced by factors such as life history and phylogenetic relatedness can improve our management of discard mortality. We evaluated the responses of six species of Pacific rockfish (black rockfish Sebastes melanops, blue rockfish S. mystinus, yellowtail rockfish S. flavidus, quillback rockfish S. maliger, canary rockfish S. pinniger, and yelloweye rockfish S. ruberrimus) captured from varying depths to forced decompression at the histological level (heart ventricle, rete mirabile, head kidney, liver, gill, and eye) as well as the macroscopic level. At the macroscopic level we focused on injuries caused by barotrauma, namely, everted esophaguses, exophthalmia, ocular emphysema, and ruptured swim bladders. Yellowtail and quillback rockfish experienced the fewest macroscopic injuries. Depth of capture influenced the presence of exophthalmia in quillback rockfish and ocular emphysema in quillback and yelloweye rockfish. Tissue injuries as a result of forced decompression included emphysema in the heart ventricle, emboli in the vessels of the rete mirabile, and emboli in the vessels of the head kidney. No injuries were observed at the histological level in the liver, gill, or eye owing to barotrauma. We could not detect a difference in the tissue‐level response to barotrauma among the six species, suggesting that all species are susceptible to high internal gas pressure during forced decompression.
Indications of Continued Overexploitation of Speckled Hind Along the Atlantic Coast of the Southeastern United States
Authors: Ziskin Gabriel L. , Harris Patrick J. , Wyanski David M. , Reichert Marcel J. M. 
Published: June 2011

AbstractFrom 1977 to 2007, speckled hind Epinephelus drummondhayi were sampled along the Atlantic coast of the southeastern United States from North Carolina to central Florida. In total, 1,365 speckled hind were obtained from two sources (fishery‐independent survey and commercial catches). The ages of specimens were estimated from increment counts on transverse sections of sagittal otoliths. Sex and reproductive state of specimens were determined by histological examination of gonads. Age of collected speckled hind ranged from 1 to 35 years, and total length (TL) ranged from 164 to 973 mm. The TL and age ranges were 169–730 mm and 1–13 years, respectively, for females; 366–730 mm and 2–13 years for mature females; 451–718 mm and 3–7 years for transitional individuals; and 500–930 mm and 4–35 years for males. There were several indications that the speckled hind population off the U.S. Atlantic coast continues to be overexploited despite a trip limit of 1 fish/vessel, which was established in 1994. The instantaneous total mortality rate (Z) and fishing mortality rate (F) increased from 1979–1981 (Z = 0.61; F = 0.48) to 2004–2007 (Z = 1.27; F = 1.14). Mean age and mean TL also decreased significantly from 7.2 years and 574 mm in 1979–1981 to 4.5 years and 462 mm in 2004–2007. No individuals above the age of 10 were collected during 2004–2007. Mean length at ages 4–6 decreased significantly from 1979–1981 to 2004–2007. During 2004–2007, 73% of specimens were immature females, and none of the sampled females was in spawning condition.
Quantifying the Extent of and Factors Associated with the Temporal Variability of Physical Stream Habitat in Headwater Streams in the Interior Columbia River Basin
Authors: Al‐Chokhachy Robert , Roper Brett B. , Archer Eric K. , Miller Scott 
Published: June 2011

AbstractThe quality and quantity of stream habitat can have profound impacts on the distribution and abundance of aquatic species. Stream networks, however, are dynamic in their response to natural‐ and human‐induced disturbance regimes, which results in spatially explicit patterns of temporal variability. Quantifying spatial patterns in habitat (temporal) variability across different sites and identifying those factors associated with different levels of variability are important steps for stream habitat assessments. We evaluated the temporal variability in stream habitat over a 9‐year period for 47headwater streams of the interior Columbia River basin. We used repeat‐measures analyses to calculate temporal variability as root mean square error for six habitat attributes at each site. Multiple linear regression analyses with root mean square error as the response were then used to quantify which landscape, climate, and disturbance attributes were associated with different levels of temporal variability among habitat attributes. Our results indicated a considerable range of temporal variability in physical stream attributes across sites and an almost fourfold difference in the overall variability at sites. Landscape factors affecting stream power, land management activities, and recent fire regimes were all factors associated with the different levels of temporal variability across sites; surprisingly, we found little association with the different climatic attributes considered herein. The observed differences in temporal variability across sites suggest that a “one‐size‐fits‐all” approach to monitoring stream habitat in response to restoration and management activities may be misleading, particularly in terms of sampling intensity, required resources, and statistical power; thus, in situ measures of temporal variability may be required for accurate assessments of statistical power.
Growth, Morphology, and Developmental Instability of Rainbow Trout, Yellowstone Cutthroat Trout, and Four Hybrid Generations
Authors: Ostberg C. O. , Duda J. J. , Graham J. H. , Zhang S. , Haywood K. P. , Miller B. , Lerud T. L. 
Published: June 2011

AbstractHybridization of cutthroat trout Oncorhynchus clarkii with nonindigenous rainbow trout O. mykiss contributes to the decline of cutthroat trout subspecies throughout their native range. Introgression by rainbow trout can swamp the gene pools of cutthroat trout populations, especially if there is little selection against hybrids. We used rainbow trout, Yellowstone cutthroat trout O. clarkii bouvieri, and rainbow trout × Yellowstone cutthroat trout F1 hybrids as parents to construct seven different line crosses: F1 hybrids (both reciprocal crosses), F2 hybrids, first‐generation backcrosses (both rainbow trout and Yellowstone cutthroat trout), and both parental taxa. We compared growth, morphology, and developmental instability among these seven crosses reared at two different temperatures. Growth was related to the proportion of rainbow trout genome present within the crosses. Meristic traits were influenced by maternal, additive, dominant, overdominant, and (probably) epistatic genetic effects. Developmental stability, however, was not disturbed in F1 hybrids, F2 hybrids, or backcrosses. Backcrosses were morphologically similar to their recurrent parent. The lack of developmental instability in hybrids suggests that there are few genetic incompatibilities preventing introgression. Our findings suggest that hybrids are not equal: that is, growth, development, character traits, and morphology differ depending on the genomic contribution from each parental species as well as the hybrid generation.
Estimating Proportional Contributions of Migratory Bull Trout from Hierarchical Populations to Mixed‐Stock Recreational Fisheries Using Genetic and Trapping Data
Authors: Warnock Will G. , Blackburn Jason K. , Rasmussen Joseph B. 
Published: June 2011

AbstractGenetic assignment methods were used to assign 104 adult migrant bull trout Salvelinus confluentus from five recreational fisheries in the Oldman River drainage (Alberta, Canada) to a baseline of three coarse‐scale genetic stocks that had been previously identified with a model‐based Bayesian clustering method. Based on individual assignment and genetic stock identification, most fisheries were largely dominated by the stock with the most proximate spawning tributaries; however, assignment tests suggested variation among source stocks in the proportions of long‐range (>90 river kilometers) migrants relative to short‐range migrants (i.e., that used nearby river systems draining spawning streams). Migrants originating from a subset of the drainage were then subjected to a finer‐scale mixed‐stock analysis in which populations at near‐tributary scales were used as the baseline. These stock proportions were compared with estimates from direct observations and were found to yield similar values to stock proportions derived from 2 years of trapping in several spawning streams. These genetic assignment methods may be used to infer contributions of large and fine‐scale hierarchical populations to mixed‐stock recreational fisheries and are especially applicable for use by inland recreational fisheries managers, which have traditionally not taken advantage of spatial genetic analysis tools to the extent used by coastal commercial fisheries managers.
Movements of Yearling Chinook Salmon during the First Summer in Marine Waters of Hood Canal, Washington
Authors: Chamberlin Joshua W. , Kagley Anna N. , Fresh Kurt L. , Quinn Thomas P. 
Published: June 2011

AbstractMigration is a fundamental component of the life history and ecology of many species, but the extent and duration of specific migrations can vary depending on species and environment. Chinook salmonOncorhynchus tshawytschaare characterized by a spectrum of life history types with different migration patterns and spatial distributions. The objective of this study was to quantify the movements of yearling Chinook salmon smolts during their initial summer in Hood Canal, a long, narrow fjord in western Puget Sound, Washington. Fifty‐eight yearling hatchery‐reared smolts were tagged with acoustic transmitters and tracked during May–August 2008 with a network of 50 receivers placed throughout Hood Canal. A total of 41 fish were detected during the study period; of these, 18 fish were still being detected in Hood Canal after 100 d. Fish initially congregated near the release site and gradually dispersed during summer; individual movement rates ranged between 0.44 and 1.52 body lengths/s. Fish movement occurred both with and against tidal currents, and nearly all fish showed some period of inactivity, especially as recorded on receivers near estuaries and tidal deltas. Eight fish (20%) were detected as leaving Hood Canal during the study, but seven of them later returned to Hood Canal. The extended use of Hood Canal as rearing habitat indicated the importance of such environments beyond their role as migratory corridors to the Pacific Ocean.