bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostic evaluation of food-related allergic diseases
Authors: Eckman John , Saini Sarbjit S , Hamilton Robert G
Published: October 2009

Food allergy is a serious and potentially life-threatening problem for an estimated 6% of children and 3.7% of adults. This review examines the diagnostic process that begins with a patient's history and physical examination. If the suspicion of IgE-mediated food allergy is compelling based on the history, skin and serology tests are routinely performed to provide confirmation for the presence of food-specific IgE antibody. In selected cases, a provocation challenge may be required as a definitive or gold standard reference test for confirmation of IgE mediated reactions to food. Variables that influence the accuracy of each of the diagnostic algorithm phases are discussed. The clinical significance of food allergen-specific IgE antibody cross-reactivity and IgE antibody epitope mapping of food allergens is overviewed. The advantages and limitations of the various diagnostic procedures are examined with an emphasis on future trends in technology and reagents.
CD74 interacts with APP and suppresses the production of Aβ
Authors: Matsuda Shuji , Matsuda Yukiko , D'Adamio Luciano
Published: October 2009

Background

Alzheimer disease (AD) is characterized by senile plaques, which are mainly composed of β amyloid (Aβ) peptides. Aβ is cleaved off from amyloid precursor protein (APP) with consecutive proteolytic processing by β-secretase and γ-secretase.

Results

Here, we show that CD74, the invariant chain of class II major histocompatibility complex, interacts with APP and serves as a negative regulator of Aβ. CD74 resembles other APP interacters such as BRI2 and BRI3, since all of them reduce the level of Aβ. However, unlike BRIs, CD74 does not reduce the secretion of sAPPα or sAPPβ. Interestingly, in HeLa cells, over expression of CD74 steers APP, but not Notch, to large vacuoles created by CD74.

Conclusion

Taken together, we propose that CD74 inhibits Aβ production by interacting with and derailing normal trafficking of APP.
Whole-genome resequencing of Escherichia coli K-12 MG1655 undergoing short-term laboratory evolution in lactate minimal media reveals flexible selection of adaptive mutations
Authors: Conrad Tom M , Joyce Andrew R , Applebee M Kenyon , Barrett Christian L , Xie Bin , Gao Yuan , Palsson Bernhard Ø
Published: October 2009

Background

Short-term laboratory evolution of bacteria followed by genomic sequencing provides insight into the mechanism of adaptive evolution, such as the number of mutations needed for adaptation, genotype-phenotype relationships, and the reproducibility of adaptive outcomes.

Results

In the present study, we describe the genome sequencing of 11 endpoints of Escherichia coli that underwent 60-day laboratory adaptive evolution under growth rate selection pressure in lactate minimal media. Two to eight mutations were identified per endpoint. Generally, each endpoint acquired mutations to different genes. The most notable exception was an 82 base-pair deletion in the rph-pyrE operon that appeared in 7 of the 11 adapted strains. This mutation conferred an approximately 15% increase to the growth rate when experimentally introduced to the wild-type background and resulted in an approximately 30% increase to growth rate when introduced to a background already harboring two adaptive mutations. Additionally, most endpoints had a mutation in a regulatory gene (crp or relA, for example) or the RNA polymerase.

Conclusions

The 82 base-pair deletion found in the rph-pyrE operon of many endpoints may function to relieve a pyrimidine biosynthesis defect present in MG1655. In contrast, a variety of regulators acquire mutations in the different endpoints, suggesting flexibility in overcoming regulatory challenges in the adaptation.
Effects of Maternal Dexamethasone Treatment in Early Pregnancy on Pituitary-Adrenal Axis in Fetal Sheep
Authors: Braun Thorsten , Li Shaofu , Sloboda Deborah M. , Li Wei , Audette Melanie C. , Moss Timothy J. M. , Matthews Stephen G. , Polglase Graeme , Nitsos Ilias , Newnham John P. , Challis John R. G.
Published: October 2009

Fetal exposure to elevated levels of bioactive glucocorticoids early in gestation, as in suspected cases of congenital adrenal hyperplasia, may result in adverse neurological events. Fetal hypothalamic-pituitary-adrenal development and function may be involved. We investigated immediate and long-term effects of maternal dexamethasone (DEX) administration early in pregnancy on fetal growth and pituitary-adrenal activity in sheep. Pregnant ewes carrying singleton fetuses (total n = 119) were randomized to control (2 ml saline/ewe) or DEX-treated groups (im injections of 0.14 mg/kg ewe weight · 12 h) at 40–41 d gestation (dG). At 50, 100, 125, and 140 dG, fetal plasma and tissues were collected. DEX-exposed fetuses were lighter than controls at 100 dG (P < 0.05) but not at any other times. Fetal plasma ACTH levels and pituitary POMC and PC-1 mRNA levels were similar between groups. Fetal plasma cortisol levels were significantly reduced after DEX exposure in both male and female fetuses at 50 dG (P < 0.05), were similar at 100 and 125 dG, but were significantly higher than controls at 140 dG. At 140 dG, there was increased adrenal P450C17 and 3β-HSD mRNA in female fetuses and reduced expression of ACTH-R mRNA in males. Fetal hepatic CBG mRNA levels mimicked plasma cortisol patterns. DEX exposure reduced CBG only in males at 50 dG (P < 0.05). Placental mRNA levels of 11β-HSD2 were increased after DEX in males (P < 0.05). Therefore, in sheep, early DEX may alter the developmental trajectory of the fetal hypothalamic-pituitary-adrenal axis, directly increasing fetal adrenal activation but not anterior pituitary function. In females, this effect may be attributed, in part, to increased fetal adrenal steroidogenic activity.
Effects of Endogenous Growth Differentiation Factor 9 on Activin A-Induced Inhibin B Production in Human Granulosa-Lutein Cells
Authors: Shi Feng-Tao , Cheung Anthony P. , Huang He-Feng , Leung Peter C. K.
Published: October 2009

Background: We recently reported on the effects of exogenous growth differentiation factor 9 (GDF9) in enhancing activin A-induced inhibin βB-subunit mRNA and inhibin B levels in human granulosa-lutein (hGL) cells by modulating key components of the activin signaling pathway. We undertook the following study to characterize the role of endogenous GDF9 in this regard.

Methods: We compared inhibin subunit (α, βA, and βB) mRNA and inhibin B levels and activation of activin receptors (ACVRs) and Smad signaling pathway in hGL cells obtained from women undergoing in vitro fertilization and cultured with and without activin A treatment after GDF9-targeting small interfering RNA transfection. GDF9, inhibin subunits, ACVR2B/1B and Smad2/3/4/7 mRNA and/or protein levels, Smad phosphorylation, and inhibin B were assessed with RT-PCR, immunoblotting, and ELISA. Data were analyzed by ANOVA followed by Tukey’s test.

Results: GDF9 was detected as mRNA and protein in hGL cells and protein in follicular fluid from all 11 patients tested. Reduced endogenous GDF9 expression after targeting small interfering RNA transfection was associated with decreased ACVR2B/1B and Smad2/3/4 but increased inhibitory Smad7 mRNA and protein levels and, consequently, reduced activin A-induced βB-subunit mRNA and inhibin B levels.

Conclusions: We report here for the first time autocrine roles for endogenous GDF9 in hGL cells in enhancing activin A-induced βB-subunit mRNA and inhibin B levels via key components of the activin signaling pathway. However, the relative contributions of GDF9 in granulosa cells vs. oocyte as autocrine/paracrine regulators of βB-subunit and inhibin B production in normal and abnormal human ovarian functions remain to be determined.
Mitochondrial Function and Insulin Resistance in Overweight and Normal-Weight Children
Authors: Fleischman Amy , Kron Matthew , Systrom David M. , Hrovat Mirko , Grinspoon Steven K.
Published: October 2009

Background: Obesity has become an epidemic in children, associated with an increase in insulin resistance and metabolic dysfunction. Mitochondrial function is known to be an important determinant of glucose metabolism in adults. However, little is known about the relationship between mitochondrial function and obesity, insulin resistance, energy expenditure, and pubertal development in children.

Methods: Seventy-four participants, 37 overweight (≥85th percentile body mass index for age and sex) and 37 normal-weight (<85th percentile) without personal or family history of diabetes mellitus were enrolled. Subjects were evaluated with an oral glucose tolerance test, metabolic markers, resting energy expenditure, Tanner staging, and 31P magnetic resonance spectroscopy of skeletal muscle for mitochondrial function.

Results: Overweight and normal-weight children showed no difference in muscle ATP synthesis [phosphocreatine (PCr) recovery after exercise] (32.4 ± 2.3 vs. 34.1 ± 2.1, P = 0.58). However, insulin-resistant children had significantly prolonged PCr recovery when compared with insulin-sensitive children, by homeostasis model assessment for insulin resistance quartile (ANOVA, P = 0.04). Similarly, insulin-resistant overweight children had PCr recovery that was prolonged compared with insulin-sensitive overweight children (P = 0.01). PCr recovery was negatively correlated with resting energy expenditure in multivariate modeling (P = 0.03). Mitochondrial function worsened during mid-puberty in association with insulin resistance.

Conclusion: Reduced skeletal muscle mitochondrial oxidative phosphorylation, assessed by PCr recovery, is associated with insulin resistance and an altered metabolic phenotype in children. Normal mitochondrial function may be associated with a healthier metabolic phenotype in overweight children. Further studies are needed to investigate the long-term physiological consequences and potential treatment strategies targeting children with reduced mitochondrial function.
On the Numerical Analysis of Inhomogeneous Continuous-Time Markov Chains
Authors: Arns M. , Buchholz P. , Panchenko A.
Published: October 2009

Inhomogeneous continuous-time Markov chains play an important role in different application areas. In contrast to homogeneous continuous-time Markov chains, where a large number of numerical analysis techniques are available and have been compared, few results about the performance of numerical techniques in the inhomogeneous case are known. This paper presents a new variant of the uniformization technique, the most efficient approach for homogeneous Markov chains. The new uniformization technique allows for the stable computation of strict bounds for the transient distribution of inhomogeneous continuous-time Markov chains, which is not possible with other numerical techniques that provide only an approximation of the distribution and asymptotic bounds. Furthermore, another variant of uniformization is presented that computes an approximation of the transient distribution and is shown to outperform standard differential equation solvers if transition rates change slowly.
An Adaptive Large Neighbourhood Search Heuristic for the Capacitated Arc-Routing Problem with Stochastic Demands
Authors: Laporte Gilbert , Musmanno Roberto , Vocaturo Francesca
Published: October 2009

The capacitated arc-routing problem with stochastic demands (CARPSD) is an extension of the well-known capacitated arc-routing problem (CARP) in which demands are stochastic. This leads to the possibility of route failures whenever the realized demand exceeds the vehicle capacity. This paper presents the CARPSD in the context of garbage collection. It describes an adaptive large-scale neighbourhood search heuristic for the problem. Computational results show the superiority of this algorithm over an alternative solution approach.
Hydrogen Embrittlement Coverage by U.S. Government Standardization Documents
Authors: Clegg Edward T.
Published: October 2009

This paper covers the Defense Specifications and Standards Program (DSSP). It describes the Department of Defense (DoD) standardization organization, discusses types of standardization documents, defines standardization terms, and covers requirements and test methods for hydrogen embrittlement in defense standardization documents. The DSSP is administered by the Deputy Under Secretary of Defense for Research and Engineering through the Defense Materials Specification and Standards Office (DMSSO). Authority is delegated by the DMSSO to Army, Navy, Air Force, and Defense Logistics Agency Departmental Standardization Offices (DEPSOs) for portions of the DSSP program. These DEPSOs further delegate responsibility among the forty plus standardization offices located at military installations. The Army Materials Technology Laboratory (AMTL) is one of these standardization offices.

The coverage of hydrogen embrittlement by DoD standardization documents is also discussed. The requirement section of specifications states the required hydrogen embrittlement relief treatment, and the quality assurance section describes the test methods to determine if embrittlement relief treatment has been successful.
Electrochemical Sensor for the Determination of Hydrogen in Metals by Potential Measurements
Authors: Mackor Adri , Wim de Kreuk C. , Schoonman Joop
Published: October 2009

An electrochemical sensor is described for the nondestructive determination of the activity of mobile elemental hydrogen in a wide range of metals, like steel and palladium. The sensor is based on the principle of a concentration cell. In this cell one of the electrodes is either the sample metal to be investigated or an ultrathin palladium layer in direct contact with the sample, acting as a sensing electrode. The other electrode functions as the reference, for which we have used palladium hydride or molybdenum bronze. The electrolyte is a liquid or preferably solid proton conductor. A version, using molybdenum bronze and thin palladium film (20 nm) electrodes and hydrogen uranyl phosphate tetrahydrate, has been found to be especially valuable because of its selectivity and long-term stability.

Various metal samples from research and industry have been investigated to yield significant potential differences between samples containing (mobile) hydrogen and those which were low in hydrogen content. The qualitative and quantitative information from these hydrogen measurements may be used for many purposes provided that suitable calibration procedures are carried out.
Diffusible Hydrogen Testing by Gas Chromatography
Authors: Quintana Marie A. , Dannecker John R.
Published: October 2009

In recent years, there has been a rising interest in diffusible hydrogen testing of steel weld metals. Several test methods have been used with varying degrees of success. The glycerin displacement method, which has been widely used, has been demonstrated to be inaccurate and under certain conditions totally unreliable. Alternative use of mercury as a collection medium provides for reliability in testing but introduces complications associated with the use of a hazardous material. Recently, gas chromatography has been used as a basis for diffusible hydrogen analysis. The method presented in this paper allows for degassing of a welded specimen in a closed chamber and subsequent analysis of the resulting gas mixture by gas chromatography. The method is flexible in that it allows for degassing at several temperatures and allows for analysis of the gas contained without consuming it entirely. The purpose of this paper is to outline the general method and provide experimental and analytical verification of its accuracy. It is discussed in comparison with other methods and equipment in current use, and some examples of its application are presented.
Prevention of Hydrogen Embrittlement by Surface Films
Authors: Murray George T.
Published: October 2009

In liquid or gaseous media, certain additives, called inhibitors, can occupy, via a strong binding energy to the base metal, atom sites on the metal surfaces, thus preventing a metal-hydrogen bond and thereby inhibiting the entry of hydrogen into the base metal. For both metallic and nonmetallic solid films, hydrogen entry can be prevented or reduced if the film has a lesser binding energy for hydrogen than the base metal and if a low solubility and/or a low diffusivity for hydrogen. Nonmetallic films appear to be the better films for preventing hydrogen entry and subsequent embrittlement of the base metal.

Data are presented for oxide and nitride films in the 50 to 3000-nm range of thickness. A 50-nm-thick film of sputtered alumina (A12O3) and a 3000-nm-thick, thermally grown oxide film appear to prevent hydrogen embrittlement in the precipitation-hardening stainless steels.
Examination of Cadmium-Plated Aircraft Fasteners for Hydrogen Embrittlement
Authors: Levy Milton , Bruggeman Gordon A.
Published: October 2009

The Army Technology Materials Laboratory (AMTL) participated in a possible hydrogen embrittlement (HE) problem involving a variety of cadmium-plated AISI4340 steel fasteners used in OH-58 and CH-47 helicopters. These fasteners were being reworked at an Army depot where cadmium plating was carried out according to Federal Specification QQ-P-416C. A three-month period was considered suspect for cadmium-plated items processed at the depot, and AMTL was supplied with a number of fasteners (bolts), both new and reworked at the depot during the suspect period, for evaluation. These fasteners were sustained load tested for evidence of HE. All of the bolts provided by the depot survived at least 200 h of testing without cracking or fracture. Several of the bolts which were plated during the suspect period and which had passed HE relief tests were deliberately fractured for examination of failure mode. The fracture topography showed no evidence of HE effects. Hardness and cadmium plating thickness measurements were consistent with specification requirements.
Assessment of the Degree of Hydrogen Embrittlement Produced in Plated High-Strength 4340 Steel by Paint Strippers Using Slow Strain Rate Testing
Authors: Pollock William J. , Grey Colin
Published: October 2009

The present work demonstrates how a slow strain rate test can be used to quantify rapidly the severity of hydrogen embrittlement produced in porous cadmium plated-and-baked high-strength 4340 steel by paint strippers. The results of multiple slow strain rate tests, conducted at a crosshead displacement rate of 2 × 10-4 mm/s using notched tension specimens in various paint strippers, show that a minimum mean fracture stress within the range of 1700 to 1850 MN/m2 can be correlated with the pass/fail criterion for acceptability of paint strippers in standard notched C-ring tests. The advantages of using a slow strain rate test as a viable alternative to existing standard methods for hydrogen embrittlement testing are discussed.
Hydrogen Transport, Microstructure, and Hydrogen-Induced Cracking in Austenitic Stainless Steels
Authors: Perng T. , Altstetter C.
Published: October 2009

Susceptibility to embrittlement in hydrogen gas was investigated for three types of stainless steel alloys having different microstructures. Both slow strain rate notched tension tests and constant load crack propagation tests were used to evaluate susceptibility at 0 to 200°C in hydrogen gas at 108 kPa (1 psig). The alloys were austenitic, ferritic, or austenite/ferrite mixtures produced by different thermomechanical treatments. The onset of embrittlement and crack propagation rates could be correlated with the microstructure of the alloys. Of particular importance to the understanding of the results are the marked hydrogen transport and solubility differences between the austenite and ferrite phases. The stress-induced transformation of austenite to body-centered cubic (bcc) martensite has particular relevance in rationalizing the behavior of various austenitic stainless steel alloys.
Hydrogen Embrittlement: Prevention and Control
Authors: Raymond Louis
Published: October 2009

Description

Papers cover all aspects of preventing of controlling hydrogen embrittlement, including the making of alloys, part fabrication, finishing, in-service performance testing, and testing actual hardware for quality assurance. This book focuses on the use and interpretation of standardized tests relative to hydrogen embrittlement, as well as on new and advanced techniques.
Increased risk of thyroid pathology in patients with thyroid hemiagenesis: results of a large cohort case–control study
Authors: Ruchala Marek , Szczepanek Ewelina , Szaflarski Witold , Moczko Jerzy , Czarnywojtek Agata , Pietz Leszek , Nowicki Michal , Niedziela Marek , Zabel Maciej , Köhrle Josef , Sowinski Jerzy
Published: October 2009

Objective

Thyroid hemiagenesis (THA) is an anomaly resulting from the developmental failure of one thyroid lobe. Etiopathogenesis, clinical significance, and management of patients in whom THA is diagnosed are still a matter of debate. The aim of the study is to provide the first systematic analysis of a large cohort of subjects with THA.

Design

Forty patients with THA are described in comparison to a control group of 80 subjects with fully developed thyroid gland.

Methods

Serum concentrations of thyrotropin (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and thyroid autoantibodies were measured. In 37 patients, thyroid ultrasonography and Tc-99m thyroid scintiscan were performed, followed by fine-needle aspiration biopsy if indicated. The remaining archival three cases were diagnosed with the use of I-131 scintiscan under basal conditions and after TSH stimulation.

Results

Patients with THA, while usually clinically euthyroid, presented with significantly higher levels of TSH and FT3 as well as with higher FT3/FT4 concentration in comparison to the control group. Furthermore, a higher incidence of associated functional, morphological, and autoimmune thyroid disorders in patients with THA was observed when compared to subjects with bilobate thyroid (P<0.05).

Conclusions

Our results revealed that individuals with THA are more likely to develop thyroid pathology. The observed high incidence of associated pathologies is presumably due to long-lasting TSH overstimulation. Therefore, THA diagnosis should be followed by systematic observation and adequate levothyroxine treatment in patients with elevated TSH level.
Zona pellucida protein ZP2 is expressed in the oocyte of Japanese quail (Coturnix japonica)
Authors: Kinoshita Mihoko , Rodler Daniela , Sugiura Kenichi , Matsushima Kayoko , Kansaku Norio , Tahara Kenichi , Tsukada Akira , Ono Hiroko , Yoshimura Takashi , Yoshizaki Norio , Tanaka Ryota , Kohsaka Tetsuya , Sasanami Tomohiro
Published: October 2009

The avian perivitelline layer (PL), a vestment homologous to the zona pellucida (ZP) of mammalian oocytes, is composed of at least three glycoproteins. Our previous studies have demonstrated that the matrix's components, ZP3 and ZPD, are synthesized in ovarian granulosa cells. Another component, ZP1, is synthesized in the liver and is transported to the ovary by blood circulation. In this study, we report the isolation of cDNA encoding quailZP2and its expression in the female bird. By RNase protection assay andin situhybridization, we demonstrate that ZP2 transcripts are restricted to the oocytes of small white follicles (SWF). The expression level ofZP2decreased dramatically during follicular development, and the highest expression was observed in the SWF. Western blot and immunohistochemical analyses using the specific antibody against ZP2 indicate that the 80 kDa protein is the authentic ZP2, and the immunoreactive ZP2 protein is also present in the oocytes. Moreover, ultrastructural analysis demonstrated that the immunoreactive ZP2 localizes to the zona radiata, the perivitelline space, and the oocyte cytoplasm in the SWF. By means of western blot analysis and immunofluorescence microscopy, we detected a possible interaction of the recombinant ZP2 with ZP3 and that this interaction might lead to the formation of amorphous structure on the cell surface. These results demonstrate for the first time that the avian ZP gene is expressed in the oocyte, and that the ZP2 protein in the oocyte might play a role for the PL formation in the immature follicles of the ovary.
Differences in oocyte development and estradiol sensitivity among mouse strains
Authors: Pepling Melissa E , Sundman Emily A , Patterson Nicole L , Gephardt Grant W , Medico Leonard , Wilson Krystal I
Published: October 2009

Mouse oocytes develop in clusters of interconnected cells called germline cysts. Shortly after birth, the majority of cysts break apart and primordial follicles form, consisting of one oocyte surrounded by granulosa cells. Concurrently, oocyte number is reduced by two-thirds. Exposure of neonatal females to estrogenic compounds causes multiple oocyte follicles that are likely germline cysts that did not break down. Supporting this idea, estrogen disrupts cyst breakdown and may regulate normal oocyte development. Previously, the CD-1 strain was used to study cyst breakdown and oocyte survival, but it is unknown if there are differences in these processes in other mouse strains. It is also unknown if there are variations in estrogen sensitivity during oocyte development. Here, we examined neonatal oocyte development in FVB, C57BL/6, and F2 hybrid (Oct4-GFP) strains, and compared them with the CD-1 strain. We found variability in oocyte development among the four strains. We also investigated estrogen sensitivity differences, and found that C57BL/6 ovaries are more sensitive to estradiol than CD-1, FVB, or Oct4-GFP ovaries. Insight into differences in oocyte development will facilitate comparison of mice generated on different genetic backgrounds. Understanding variations in estrogen sensitivity will lead to better understanding of the risks of environmental estrogen exposure in humans.
Ecotype Distinctions among Steelhead in Hood River, Oregon, Allow Real‐Time Genetic Assignment of Conservation Broodstocks
Authors: Matala A. P. , French R. , Olsen E. , Ardren W. R.
Published: October 2009

Efforts to rehabilitate threatened summer‐run (SR) and winter‐run (WR) populations of steelhead Oncorhynchus mykiss in the Hood River, Oregon, include operation of two conservation hatchery programs. Annual collection of discrete broodstocks relies on identification of SR and WR fish based on return time, reproductive state, and other physical and behavioral characteristics. An increased likelihood of misidentification occurs in the spring, when SR and WR return times overlap. The resulting interbreeding between ecotypes in the hatchery imposes serious genetic risks to wild SR and WR steelhead populations. We characterized life history differences between Hood River SR and WR steelhead and evaluated genetic structure using a suite of microsatellite loci. Significant differences in life history, including age at return and fork length, were corroborated by spatially influenced genetic structure among SR and WR fish; SR fish spawn in the west fork of the Hood River, while WR fish spawn in the east and middle forks. Temporal and spatial distinctions persist among Hood River steelhead ecotypes despite past operation of segregated hatchery programs utilizing out‐of‐basin stocks. We evaluated the feasibility of using real‐time genetic assignment tests to differentiate SR from WR among candidate broodstock fish captured downstream of spawning grounds. Among adult steelhead of known origin, we observed 91.5% assignment accuracy for WR fish and 77.7% accuracy for SR fish. A rapid‐response protocol was subsequently developed that provides hatchery managers with genetic assignment of broodstock to ecotypes within 24 h after interrogation of returning fish.
Migration and Spawning of American Shad in the James River, Virginia
Authors: Aunins Aaron , Olney John E.
Published: October 2009

Acoustic telemetry and ichthyoplankton surveys were used to characterize the migratory behavior and spawning grounds of American shad Alosa sapidissima in the James River, Virginia. Seven acoustic monitoring stations spanned a distance of 95 river kilometers extending downstream from just below the fall line in Richmond to the estuarine portion of the river at Hog Island. Ninety‐three fish were tagged in the estuarine portion of the river near Hog Island on 21 March 2005. Eighty‐six fish exhibited fallback behavior, and 45 of these fish eventually abandoned the migration. Forty‐six fish were eventually detected upstream at the mouths of the two major James River tributaries (Appomattox and Chickahominy rivers), within the main‐stem James River up to the fall line, or both. Upstream movements detected by stationary hydrophones during the prespawning migration were significantly related to flooding tides, and movements downstream during the postspawning emigration were significantly related to ebbing tides. However, there was no significant relationship between time of day and movements during the prespawning or postspawning migration phase. Movement patterns suggested three primary areas of residency located within the 65‐km reach below the fall line downstream to Upper Brandon Plantation, although some fish exhibited behaviors that were inconsistent with a specific residence area. Ichthyoplankton collections of eggs and yolk sac larvae indicated that the principal spawning grounds were located in a 33.5‐km reach extending downstream from the fall line, a finding consistent with repeated detection of a majority of the tagged cohort within this reach.
Influences of Wildfire, Habitat Size, and Connectivity on Trout in Headwater Streams Revealed by Patterns of Genetic Diversity
Authors: Neville Helen , Dunham Jason , Rosenberger Amanda , Umek John , Nelson Brooke
Published: October 2009

Wildfire is an important natural process in many stream ecosystems, but the ability of fish to respond to wildfire‐related disturbances is increasingly constrained by human activities that fragment and degrade stream habitats. In this study, we used molecular genetic markers (nuclear microsatellites) to examine the effects of wildfire and related disturbances along with habitat fragmentation on native rainbow trout in the Boise and Payette River basins, Idaho. We surveyed the genetic diversity of fish in 55 tributary streams to compare the level of diversity in samples without the recent influence of wildfire with that of those influenced by stand‐replacing wildfire and those influenced by both wildfire and a severe channel‐reorganizing disturbance. Stream habitats also varied substantially in size (catchment basin area) and isolation caused by road culverts. Based on prior work in our study streams, we expected that both wildfire and channel reorganization would reduce local population sizes significantly. Accordingly, we expected that wildfire‐related disturbances would reduce genetic diversity via founder effects or population bottlenecks. Our results, however, showed little evidence of these influences. In contrast, the level of genetic diversity was lower in fish collected upstream of culvert barriers, probably because of restricted gene flow. We also observed the expected positive correlation between habitat size and genetic diversity, which suggested the importance of larger local population sizes and habitat diversity in maintaining genetic diversity. An unexpected finding was that 15 of the 55 samples showed genetic evidence of hybridization between rainbow trout Oncorhynchus mykiss and nonnative cutthroat trout O. clarkii. The results of this study suggest that human influences such as barriers to dispersal and introductions of nonnative fish may pose greater threats to populations of native trout than wildfire itself.
Inferences on the Latent Mortality of Snake River Spring–Summer‐Run Chinook Salmon Using Spawner–Recruit Models
Authors: Hinrichsen Richard A. , Fisher Timothy R.
Published: October 2009

The rapid decline of the Snake River spring–summer‐run Chinook salmon Oncorhynchus tshawytscha evolutionarily significant unit (ESU) in the 1990s led a group of scientists to develop the Plan for Analyzing and Testing Hypotheses (PATH). Under this plan, researchers used spawner–recruit (SR) data to estimate the survival of out‐migrating smolts through eight dams of the Federal Columbia River Power System (FCRPS). Direct measurements of survival during out‐migration, known as passage survival, were not available, so the PATH scientists estimated survival for index populations using trends from Ricker‐type SR models. This modeling framework had the advantage of estimating both the direct and indirect (or latent) effects (FCRPS‐related mortalities that do not occur until the smolts have passed the FCRPS dams) on the life cycle survival of the populations. We evaluated the SR model used by the PATH scientists by examining how changes in model structure affected important inferences. We calculated condition indexes as measures of the sensitivity of the model results to perturbations in the SR data and model structure, finding that the results were highly sensitive to certain assumptions. In particular, we found that changing the Ricker α term from a population‐specific parameter to a parameter common to all of the populations in the ESU changed total passage survival from 9% to 56% and latent mortality from one‐half the total passage mortality to a value that is not significantly different from zero. Therefore, the condition indexes revealed high potential sensitivities of the SR model results to perturbations in data and model structure. Although information criteria indicated that the population‐specific model had a poorer fit than lower‐parameter models, it was impossible to resolve the question as to whether there was latent mortality.
A Statewide Assessment of Mercury Dynamics in North Carolina Water Bodies and Fish
Authors: Sackett Dana K. , Aday D. Derek , Rice James A. , Cope W. Gregory
Published: October 2009

Mercury contamination of aquatic systems has received much attention recently because of potential health effects on humans and wildlife. Although the factors affecting mercury deposition, its conversion to biologically active methylmercury, and its bioaccumulation in aquatic systems have been identified, equivocal results for particular species and systems have hampered policy making. Our study addresses this problem through a comprehensive, statewide synthesis of the available data on fish mercury contamination in North Carolina and the environmental factors associated with methylmercury formation and transport through aquatic food webs. Using data collected by the North Carolina Department of Environment and Natural Resources, the U.S. Environmental Protection Agency, and others, we examined the relationships between a suite of biotic and abiotic factors and tissue mercury concentrations in fish from North Carolina water bodies. Multivariate tests were conducted to create predictive models relating environmental variables to mercury levels in fish, and Akaike's information criterion was used to examine the relative strengths of the candidate models. The best model in our analyses (R2 = 0.81) included species, fish trophic status, ecoregion, and pH. Other important drivers of mercury accumulation were land use patterns (the percentage of the subbasin that is agricultural) and site type (swamps versus lakes, rivers, and bays). Although previous investigations have indicated similar individual relationships, our study is unique in that we examined the relative importance of a large number of biotic and abiotic variables across a range of environments, ecosystems, and species. The results of these analyses should help policymakers in making risk assessment decisions and serve as a template for future investigations.
Temperature and Flow Effects on Migration Timing of Chinook Salmon Smolts
Authors: Sykes Gregory E. , Johnson Chris J. , Shrimpton J. Mark
Published: October 2009

Physiological and behavioral changes occur in the spring when juvenile Pacific salmon Oncorhynchus spp. undergo smolting. Survival is maximized if the timing of these changes coincides with migration from fresh to marine environments. Therefore, understanding how environmental conditions influence the onset, duration, and termination of smolting can have substantial management implications, particularly for flow‐controlled rivers. We used an information‐theoretic model comparison analysis to investigate the roles of daily mean temperature, temperature experience (accumulated thermal units [ATU]), photoperiod, and flow on the timing of the downstream migration of Chinook salmon O. tshawytscha smolts from the Nechako River in central British Columbia. Both binary (migration or not) and count (the total number of migrants) models were developed that predicted the downstream migration of Chinook salmon based on data collected from fish captured at rotary‐screw traps from 1992 to 2004. The analyses identified a combination of temperature experience, flow, and the number of spawners as best able to describe the observed migration patterns. In addition, increasing ATU had a positive influence on migration, while increasing flow had a negative influence. Temperature experience was found to have more influence on migration than daily mean temperature. The predictive ability of each model was tested with 2 years of independent data. The count model accurately predicted the general trends in migration and, in particular, the termination of migration, but not the daily fluctuations in movement. By contrast, the binary model predicted whether fish would migrate on a given day with accuracies of 93% and 99%, respectively, for the 2 years tested. Temperature experience was more strongly linked to migration than the daily or threshold temperature; warmer temperatures resulted in earlier migration. Our data suggest that flow plays an important role once migration is under way and may even serve as a termination cue. Furthermore, the number of migrants and the probability of migration was positively related to the number of spawners. Based on the results of this study, flow manipulations that change the timing, duration, or magnitude of temperature and flow in the spring could affect the migration of Chinook salmon. Both temperature and river flow should be considered when one is managing flow‐controlled watersheds for salmon productivity.
Distribution and Migration of Juvenile Chinook Salmon Derived from Coded Wire Tag Recoveries along the Continental Shelf of Western North America
Authors: Trudel M. , Fisher J. , Orsi J. A. , Morris J. F. T. , Thiess M. E. , Sweeting R. M. , Hinton S. , Fergusson E. A. , Welch D. W.
Published: October 2009

The effects of ocean conditions on highly migratory species such as salmon are difficult to assess owing to the diversity of environments they encounter during their marine life. In this study, we reconstructed the initial ocean migration routes of juvenile Chinook salmonOncorhynchus tshawytschaoriginating from Oregon to Southeast Alaska using coded wire tag recovery data from Canadian Department of Fisheries and Oceans and National Marine Fisheries Service research surveys conducted between 1995 and 2006. Over this 12‐year period, 1,862 coded‐wire‐tagged juvenile Chinook salmon were recovered along the coasts of Oregon, Washington, British Columbia, and Alaska from March to November. Except for those from the Columbia River, most juvenile Chinook salmon remained within 100–200 km of their natal rivers until their second year at sea, irrespective of their freshwater history and adult run timing. Northward migration of most coastal stocks was initiated during their second or possibly third year at sea, whereas the Strait of Georgia and Puget Sound stocks primarily migrated onto the continental shelf after their first year at sea. In contrast, Columbia River Chinook salmon generally undertook a rapid northward migration that varied among life histories and stocks. Columbia River spring Chinook salmon were recovered as far north as Prince William Sound, Alaska, during their first summer at sea, whereas very few Columbia River fall Chinook salmon were recovered north of Vancouver Island. In addition to northern migrants, a fraction of the Columbia River spring and fall Chinook salmon actively migrated south of the Columbia River. The stock‐specific initial ocean migration routes described in this study will aid in the identification of the appropriate spatial and temporal scales for assessing the processes regulating Chinook salmon recruitment in the marine environment.
Seasonal Stock‐Specific Migrations of Juvenile Sockeye Salmon along the West Coast of North America: Implications for Growth
Authors: Tucker S. , Trudel M. , Welch D. W. , Candy J. R. , Morris J. F. T. , Thiess M. E. , Wallace C. , Teel D. J. , Crawford W. , Farley E. V. , Beacham T. D.
Published: October 2009

Knowledge of the migratory habits of juvenile Pacific salmon Oncorhynchus spp. is required to test the hypothesis that ocean food resources are a limiting factor in their production. Using DNA stock identification techniques, we reconstructed the regional and seasonal changes in the stock composition of juvenile sockeye salmon O. nerka (n = 4,062) collected from coastal Washington to the Alaska Peninsula in coastal trawl surveys from May to February 1996–2007. Individuals were allocated to 14 regional populations. The majority were allocated to stocks from the Fraser River system (42%), while west coast Vancouver Island stocks accounted for 15% of the total catch; Nass and Skeena River sockeye salmon constituted 14% and Rivers Inlet 6% of the total. The remainder of the stocks identified individually contributed less than 5% of the sockeye salmon analyzed. These proportions generally reflected the abundance of those populations. In spring and summer, the majority of fish were caught in close proximity to their rivers of origin, lending further support to the allocations. By fall, sockeye salmon were caught as far north and west as the Alaska Peninsula, the majority being caught from central British Columbia to Southeast Alaska. Juvenile sockeye salmon generally disappeared from the coast by winter, suggesting dispersion into the Gulf of Alaska. Within each region, the proportional stock composition changed as the seasons progressed, with northward (and in some cases, rapid) migration along the coast. We also demonstrated stock‐specific differences in migration patterns. For each stock identified, body size and energy density were higher at northern latitudes, suggesting that there is an environmental or food web influence on growth or that faster growing fish initiated their northward migration earlier.
Diet, Movement, and Growth of Dolly Varden in Response to Sockeye Salmon Subsidies
Authors: Denton Keith P. , Rich Harry B. , Quinn Thomas P.
Published: October 2009

A large and growing body of literature has documented the transfer of marine‐derived nutrients from the ocean to freshwater and riparian systems by semelparous Pacific salmon Oncorhynchus spp. The pathways by which these nutrients reach resident fish are often indirect, and the evidence for direct benefits to the resident fish is not always conclusive. However, the consumption of salmon tissue (in one form or another) by resident fish would constitute a direct and efficient pathway for energy transfer. We studied a population of small‐bodied, nonanadromous Dolly Varden Salvelinus malma feeding on the fry and eggs of sockeye salmon O. nerka and blowfly (family Calliphoridae) larvae that had fed on salmon carcasses at a series of spring‐fed and otherwise unproductive ponds in southwestern Alaska. The Dolly Varden fed heavily on sockeye salmon fry when available, shifted their diet almost exclusively to eggs after salmon spawning commenced, and then shifted to blowfly larvae toward the end of the season. Dolly Varden large enough to eat eggs moved into ponds where sockeye salmon spawn synchronously with the arrival of the salmon, and Dolly Varden growth rates increased greatly once salmon eggs and blowfly maggots were available. Young‐of‐the‐year Dolly Varden, which were too small to eat eggs and fry, were concentrated in small streams between ponds where fewer sockeye salmon spawn, perhaps to minimize the risk of predation from larger conspecifics. These results indicate the importance of a pulse of salmon‐related food resources for this population of resident fish and their adaptations to take advantage of these resources. It is likely that similar dependence occurs in other systems where sockeye salmon produce a suite of temporally predictable energy resources; thus, resident fish may depend on large populations of salmon.
Utilização de medicamentos e fatores associados entre crianças residentes em áreas pobres
Authors: Santos Djanilson Barbosa , Barreto Mauricio Lima , Coelho Helena Lutescia Luna
Published: October 2009

OBJETIVO: Descrever o perfil de uso de medicamentos entre crianças residentes em áreas pobres e fatores associados. MÉTODOS: Estudo transversal de base populacional que incluiu 1.382 crianças entre quatro e 11 anos de idade, selecionadas por amostragem aleatória de 24 micro-áreas representativas das zonas mais pobres da população residente no município de Salvador, BA, em 2006. A variável dependente foi o consumo de medicamentos nos 15 dias anteriores à realização dos inquéritos. Foram considerados três grupos de variáveis explanatórias: socioeconômicas, estado de saúde da criança e utilização dos serviços de saúde. A análise ajustada utilizou regressão de Poisson seguindo um modelo conceitual hierarquizado. RESULTADOS: A prevalência de consumo de medicamentos em crianças foi de 48%. As crianças do sexo feminino apresentaram prevalência de utilização de medicamentos superior ao sexo masculino, 50,9% e 45,4%, respectivamente (p=0,004). A prevalência de uso de medicamentos diminuiu significativamente com a idade (p<0,001) em ambos os sexos. Os grupos farmacológicos mais utilizados foram os analgésicos/antitérmicos (25,5%), antibacterianos sistêmicos (6,5%) e antitussígenos/expectorantes (6,2%). Na análise multivariada os fatores determinantes de maior utilização de medicamentos foram: idade (quatro a cinco, seis, sete a oito anos), sexo feminino, mães de cor da pele branca, pior percepção de saúde, interrupção de atividades por problemas de saúde e atendimento de saúde independentemente de estar doente nos últimos 15 dias, gasto com medicamentos no último mês e realização de consultas ao médico nos últimos três meses. CONCLUSÕES: A prevalência de uso de medicamentos entre crianças pobres estudadas foi inferior à verificada em outros estudos populacionais no Brasil, mas semelhante à de adultos. A identificação de grupos mais sujeitos ao uso excessivo de medicamentos pode embasar estratégias para promoção de seu uso racional.
Estresse no trabalho e hipertensão arterial em mulheres no Estudo Pró-Saúde: Estudo Pró-Saúde (Pro-Health Study)
Authors: Alves Márcia Guimarães de Mello , Chor Dóra , Faerstein Eduardo , Werneck Guilherme L , Lopes Claudia S
Published: October 2009

Com o objetivo de analisar a associação entre estresse no trabalho e hipertensão arterial na população feminina, foi realizado estudo transversal com 1.819 mulheres participantes do Estudo Pró-Saúde no Rio de Janeiro, RJ, entre 1999 e 2001. Foi utilizada a versão brasileira da escala reduzida de estresse no trabalho (modelo demanda-controle). A prevalência global de hipertensão arterial aferida (>140/90 mmHg e/ou uso de medicação anti-hipertensiva) foi de 24%. Comparadas com participantes com trabalho classificado como de baixa exigência, as razões ajustadas de prevalências de hipertensão arterial de mulheres em trabalhos de alta exigência, passivos e ativos, foram, respectivamente, de 0,93 (IC 95%: 0,72;1,20), 1,06 (IC 95%: 0,86;1,32) e 1,14 (IC 95%: 0,88;1,47). Sugere-se a realização de análises longitudinais para elucidar o papel dessas características psicossociais do ambiente de trabalho na determinação da hipertensão arterial.