bluuebunny/crossref_metadata_2025 huggingface dataset:
A model of Costeff Syndrome reveals metabolic and protective functions of mitochondrial OPA3
Authors: Pei Wuhong , Kratz Lisa E. , Bernardini Isa , Sood Raman , Yokogawa Tohei , Dorward Heidi , Ciccone Carla , Kelley Richard I. , Anikster Yair , Burgess Harold A. , Huizing Marjan , Feldman Benjamin
Published: July 2010

Costeff Syndrome, which is caused by mutations in the OPTIC ATROPHY 3 (OPA3) gene, is an early-onset syndrome characterized by urinary excretion of 3-methylglutaconic acid (MGC), optic atrophy and movement disorders, including ataxia and extrapyramidal dysfunction. The OPA3 protein is enriched in the inner mitochondrial membrane and has mitochondrial targeting signals, but a requirement for mitochondrial localization has not been demonstrated. We find zebrafish opa3 mRNA to be expressed in the optic nerve and retinal layers, the counterparts of which in humans have high mitochondrial activity. Transcripts of zebrafish opa3 are also expressed in the embryonic brain, inner ear, heart, liver, intestine and swim bladder. We isolated a zebrafish opa3 null allele for which homozygous mutants display increased MGC levels, optic nerve deficits, ataxia and an extrapyramidal movement disorder. This correspondence of metabolic, ophthalmologic and movement abnormalities between humans and zebrafish demonstrates a phylogenetic conservation of OPA3 function. We also find that delivery of exogenous Opa3 can reduce increased MGC levels in opa3 mutants, and this reduction requires the mitochondrial localization signals of Opa3. By manipulating MGC precursor availability, we infer that elevated MGC in opa3 mutants derives from extra-mitochondrial HMG-CoA through a non-canonical pathway. The opa3 mutants have normal mitochondrial oxidative phosphorylation profiles, but are nonetheless sensitive to inhibitors of the electron transport chain, which supports clinical recommendations that individuals with Costeff Syndrome avoid mitochondria-damaging agents. In summary, this paper introduces a faithful Costeff Syndrome model and demonstrates a requirement for mitochondrial OPA3 to limit HMG-CoA-derived MGC and protect the electron transport chain against inhibitory compounds.
Spps, aDrosophilaSp1/KLF family member, binds to PREs and is required for PRE activity late in development
Authors: Brown J. Lesley , Kassis Judith A.
Published: July 2010

The Polycomb group of proteins (PcG) is important for transcriptional repression and silencing in all higher eukaryotes. In Drosophila, PcG proteins are recruited to the DNA by Polycomb-group response elements (PREs), regulatory sequences whose activity depends on the binding of many different sequence-specific DNA-binding proteins. We previously showed that a binding site for the Sp1/KLF family of zinc-finger proteins is required for PRE activity. Here, we report that the Sp1/KLF family member Spps binds specifically to Ubx and engrailed PREs, and that Spps binds to polytene chromosomes in a pattern virtually identical to that of the PcG protein, Psc. A deletion of the Spps gene causes lethality late in development and a loss in pairing-sensitive silencing, an activity associated with PREs. Finally, the Spps mutation enhances the phenotype of pho mutants. We suggest that Spps may work with, or in parallel to, Pho to recruit PcG protein complexes to PREs.
Scapula development is governed by genetic interactions ofPbx1with its family members and withEmx2via their cooperative control ofAlx1
Authors: Capellini Terence D. , Vaccari Giulia , Ferretti Elisabetta , Fantini Sebastian , He Mu , Pellegrini Massimo , Quintana Laura , Di Giacomo Giuseppina , Sharpe James , Selleri Licia , Zappavigna Vincenzo
Published: July 2010

The genetic pathways underlying shoulder blade development are largely unknown, as gene networks controlling limb morphogenesis have limited influence on scapula formation. Analysis of mouse mutants for Pbx and Emx2 genes has suggested their potential roles in girdle development. In this study, by generating compound mutant mice, we examined the genetic control of scapula development by Pbx genes and their functional relationship with Emx2. Analyses of Pbx and Pbx1;Emx2 compound mutants revealed that Pbx genes share overlapping functions in shoulder development and that Pbx1 genetically interacts with Emx2 in this process. Here, we provide a biochemical basis for Pbx1;Emx2 genetic interaction by showing that Pbx1 and Emx2 can bind specific DNA sequences as heterodimers. Moreover, the expression of genes crucial for scapula development is altered in these mutants, indicating that Pbx genes act upstream of essential pathways for scapula formation. In particular, expression of Alx1, an effector of scapula blade patterning, is absent in all compound mutants. We demonstrate that Pbx1 and Emx2 bind in vivo to a conserved sequence upstream of Alx1 and cooperatively activate its transcription via this potential regulatory element. Our results establish an essential role for Pbx1 in genetic interactions with its family members and with Emx2 and delineate novel regulatory networks in shoulder girdle development.
MEX-5 enrichment in the C. elegans early embryo mediated by differential diffusion
Authors: Daniels Brian R. , Dobrowsky Terrence M. , Perkins Edward M. , Sun Sean X. , Wirtz Denis
Published: July 2010

Specification of germline and somatic cell lineages in C. elegans originates in the polarized single-cell zygote. Several cell-fate determinants are partitioned unequally along the anterior-posterior axis of the zygote, ensuring the daughter cells a unique inheritance upon asymmetric cell division. Recent studies have revealed that partitioning of the germline determinant PIE-1 and the somatic determinant MEX-5 involve protein redistribution accompanied by spatiotemporal changes in protein diffusion rates. Here, we characterize the dynamics of MEX-5 in the zygote and propose a novel reaction/diffusion model to explain both its anterior enrichment and its remarkable intracellular dynamics without requiring asymmetrically distributed binding sites. We propose that asymmetric cortically localized PAR proteins mediate the anterior enrichment of MEX-5 by reversibly changing its diffusion rate at spatially distinct points in the embryo, thus generating a stable concentration gradient along the anterior-posterior axis of the cell. This work extends the scope of reaction/diffusion models to include not only germline morphogens, but also somatic determinants.
Letter: High-Energy Electron Transfer Dissociation Using a Tandem Time-of-Flight Mass Spectrometer with an Electrospray Ionization Ion Source
Authors: Nagao Hirofumi , Shimma Shuichi , Hayakawa Shigeo , Awazu Kunio , Toyoda Michisato
Published: July 2010

A tandem time-of-flight (TOF) mass spectrometer with an electrospray ionization (ESI) ion source (ESI-TOF/quadTOF) was enhanced to perform high-energy electron transfer dissociation (ETD) experiments. Specifically, the collision cell for rare gas targets of ESI-TOF/quadTOF was replaced with one for alkali metal targets. High-energy ETD spectra were obtained of doubly protonated polypeptides and a phosphopeptide using a Cs target. Peaks due to several c- and z-type fragment ions formed by the high-energy ETD process were clearly observed in all cases. These results demonstrate that high-energy ETD can be performed using ESI-TOF/quadTOF.
Analysis of the Physicochemical State of C-Reactive Protein in Different Preparations Including 2 Certified Reference Materials
Authors: Rzychon Malgorzata , Zegers Ingrid , Schimmel Heinz
Published: July 2010

BACKGROUND

Standardization of clinical measurements of C-reactive protein (CRP) is based on the availability of reference materials. The serum protein reference material ERM-DA470 was used as a calibrant for various commercially available immunoassays but has now been exhausted. The recently released ERM-DA470k/IFCC was intended to fully replace ERM-DA470. However, the new material was not suited for the certification of CRP because of a bias introduced by the lyophilization process that caused loss of about 20% of CRP measurable by routine immunoassays, compared with the nonlyophilized material that was stored in a liquid frozen state.

METHODS

We investigated the physicochemical state of CRP in a set of 4 lyophilized and 2 nonlyophilized serum-based CRP-containing materials by semi-native gel electrophoresis, Western blotting, and gel filtration.

RESULTS

We detected a monomeric form of CRP (mCRP) in lyophilized materials at a concentration significantly higher than seen in the materials not subjected to lyophilization. Different reconstitution protocols led to variations of the monomeric CRP fraction found in reconstituted, previously lyophilized material.

CONCLUSIONS

Most of the 20% loss in measured CRP after lyophilization of the material can be accounted for by the dissociation of natively pentameric CRP into subunits. The observed dissociation results from lyophilization and subsequent reconstitution of the material at insufficient concentration levels of calcium ions. In the presence of various protein forms, differences in antibody specificity and reactivity between immunoassays and alterations of stoichiometry of antigen–antibody interactions can contribute to the divergence of the measured values.
A proposed accelerated field stake test for rapid assessment of wood preservative systems
Authors: Schultz Tor P. , Nicholas Darrel D.
Published: July 2010

A ground-contact field test which would yield faster deterioration data when testing new wood preservative systems would be useful. This paper reports on an accelerated field test concept where wood samples are treated with a proposed preservative and a reference system with known efficacy, with the treated samples installed next to ground-contact wood feeder stakes that are already infected with wood decay fungi. This method was employed to compare decay efficacies of wood treated with four copper systems commonly available in the US. Two preliminary short-term studies show that this test method can provide differentiation between preservatives systems after only a short exposure period.
Duration of Illness in Infants With Bronchiolitis Evaluated in the Emergency Department
Authors: Petruzella Frank D. , Gorelick Marc H.
Published: July 2010

OBJECTIVES:

To describe the duration of illness in infants with first-time bronchiolitis who present to an emergency department (ED) and assess the burden of the illness on caregivers and families.

METHODS:

This was a prospective cohort study of infants younger than 12 months who presented to a tertiary care children's hospital ED with a first episode of bronchiolitis. Subjects were excluded if they had a history of bronchodilator use or immunocompromise. Demographic and clinical data were collected in the ED. Outcomes data were collected by weekly telephone interviews for 4 weeks or until the subject was free of cough for 24 hours.

RESULTS:

Ninety-five infants were enrolled from November 2007 to March 2008. Median duration of symptoms was 15 days; 25% of the infants remained symptomatic after 21 days. Subjects with a history of eczema trended toward a longer median duration of symptoms when compared with those who did not (18 days [interquartile range (IQR): 15.5–24] and 15 days [IQR: 11–19], respectively; P = .055). Duration of symptoms did not significantly vary with regards to respiratory syncytial virus status or secondhand smoke exposure. Subjects missed a median of 2.5 days (IQR: 0.5–5.5) of day care, and caregivers missed a median of 2 days (IQR: 1–4) of work. Of these infants, 37.1% (95% confidence interval: 24.3–44.1) had a subsequent unscheduled medical visit.

CONCLUSIONS:

Infants seen in the ED for bronchiolitis have a prolonged disease course, with substantial burden to the family. Symptom duration may be influenced by a propensity toward atopy. Clinicians may use this information for counseling families.
Pediatric Gliomatosis Cerebri Mimicking Acute Disseminated Encephalomyelitis
Authors: Richard Hope T. , Harrison Jason F. , Abel Ty W. , Maertens Paul , Martino Anthony M. , Sosnowski Jeffrey S.
Published: July 2010

Gliomatosis cerebri (GC) is a diffuse infiltrating glial neoplasm of astrocytic origin. GC in children is rare and difficult to diagnose, often presenting with a variety of signs and symptoms that may mimic encephalitis. We discuss here the presentation and diagnosis of GC in 2 children who were initially suspected to have acute disseminating encephalomyelitis. In this report we underscore the limitations of relying on clinical presentation and neuroimaging as well as the essential role of pathologic evaluation for the diagnosis of GC in children.
Thyrotropin-Secreting Pituitary Adenoma in an Adolescent Boy: Challenges in Management
Authors: Kessler Marion , David Raphael , Pawelczak Melissa , Hanono Anat , Shah Bina
Published: July 2010

Thyrotropinomas tend to be aggressive, invasive tumors that are difficult to resect because of their marked fibrosis and their proximity to vital structures such as the optic chiasm. The latter characteristic also limits the use of radiation therapy. In the few cases reported of children younger than 18 years whose thyrotropinomas were treated surgically, the results were disappointing. We present here the case of a 16-year-old boy with a thyrotropin-secreting pituitary macroadenoma who underwent partial resection via a transsphenoidal approach and was left with significant residual tumor and continued hyperthyroidism. He subsequently received 4 years of long-acting release somatostatin therapy, during which he has remained euthyroid without requiring antithyroid medication. To our knowledge, this is thus far the longest duration of somatostatin therapy in the pediatric age group. This regimen also achieved a decrease in compression of the optic nerve and prevented further tumor growth. We review here the current literature on somatostatin analog treatment including molecular mechanisms and promising new treatment modalities, such as the heterodimerization of dopamine and somatostatin receptors. We conclude that this has been a useful adjuvant treatment for our adolescent patient.
Universal Versus Targeted Blood Cholesterol Screening Among Youth: The CARDIAC Project
Authors: Ritchie Susan K. , Murphy Emily C.-S. , Ice Christa , Cottrell Lesley A. , Minor Valerie , Elliott Eloise , Neal William
Published: July 2010

OBJECTIVES:

The goal was to determine the sensitivity and specificity of family history in identifying children with severe or genetic hyperlipidemias in a rural, predominantly white population.

METHODS:

A total of 20266 fifth-grade children in West Virginia, from the Coronary Artery Risk Detection in Appalachian Communities (CARDIAC) Project, who completed a family history and fasting lipid profile were used in analyses. The relationship between hyperlipidemia and family history was determined, and the use of family history to predict the need for pharmacologic treatment among children with dyslipidemia was evaluated.

RESULTS:

A total of 71.4% of children met the National Cholesterol Education Program (NCEP) guidelines for cholesterol screening on the basis of positive family history. Of those, 1204 (8.3%) were considered to have dyslipidemia (low-density lipoprotein ≥130 mg/dL), and 1.2% of these children with dyslipidemia warranted possible pharmacologic treatment (low-density lipoprotein ≥160 mg/dL). Of the 28.6% who did not have a positive family history (did not meet NCEP guidelines), 548 (9.5%) had dyslipidemia, 1.7% of whom warranted pharmacologic treatment. Sensitivity and specificity data demonstrated that family history does not provide a strong indication as to whether pharmacologic treatment may be warranted.

CONCLUSIONS:

Results indicate that the use of family history to determine the need for cholesterol screening in children would have (1) missed many with moderate dyslipidemia and (2) failed to detect a substantial number with likely genetic dyslipidemias that would require pharmacologic treatment. The use of universal cholesterol screening would identify all children with severe dyslipidemia, allowing for proper intervention and follow-up and leading to the prevention of future atherosclerotic disease.
Day-by-Day Postnatal Survival in Very Low Birth Weight Infants
Authors: Mohamed Mohamed A. , Nada Ayman , Aly Hany
Published: July 2010

OBJECTIVES:

Postnatal survival rates of very low birth weight (VLBW) infants are well established for each birth weight or gestational age category. These figures do not differentiate viable infants who survive the first few days of life from extremely immature ones who die shortly after birth. This study aimed to develop standardized curves for day-by-day postnatal survival rates of VLBW infants.

METHODS:

National Inpatient Sample Database and its pediatrics-only subportion were analyzed for the years 1997–2004. Infants with birth weight <1500 g were included in the study. Infants were classified according to their birth weight into 4 groups: <500, 500 to 749, 750 to 999, and 1000 to 1499 g. Postnatal survival rates were calculated for each group at birth and at 1, 2, 3, 4 to 5, 6 to 7, 14, 21, 28, and >28 postnatal days.

RESULTS:

Overall survival for infants with birth weight <500 g was 8%. Those who lived through the first 3 days of life had a chance of survival up to 50%. Infants in the 500- to 749-g group had overall survival rate of 50% that increased to 70% if they survived through the third day and 80% by the end of the first week. There was no improvement in the overall survival of any birth weight category over the years of the study.

CONCLUSIONS:

VLBW infants who survive the first few postnatal days have a considerably better chance for life. We can predict postnatal survival chances for each birth weight category on a day-by-day basis until discharge.
Length of Intravenous Antibiotic Therapy and Treatment Failure in Infants With Urinary Tract Infections
Authors: Brady Patrick W. , Conway Patrick H. , Goudie Anthony
Published: July 2010

OBJECTIVE:

The goal was to determine the association between short-duration (≤3 days) and long-duration (≥4 days) intravenous antibiotic therapy and treatment failure in a cohort of young infants hospitalized with urinary tract infections (UTIs).

METHODS:

We conducted a retrospective cohort study of infants <6 months of age who were hospitalized with UTIs between 1999 and 2004 at 24 children's hospitals in the Pediatric Health Information System. Our main model adjusted for all covariates, propensity scores, and clustering according to hospital to evaluate the effect of short versus long courses of inpatient intravenous antibiotic therapy on treatment failure, defined as readmission because of UTI within 30 days.

RESULTS:

Of the 12 333 infants who met the inclusion criteria, 240 (1.9%) experienced treatment failure. The treatment failure rates were 1.6% for children who received short-course intravenous antibiotic treatment and 2.2% for children who received long-course treatment. Treatment courses varied substantially across hospitals and with patient-level characteristics. After multivariate adjustment, including propensity scores, there was no significant association between treatment group and outcomes, with an odds ratio for long versus short treatment of 1.02 (95% confidence interval: 0.77–1.35). Known presence of genitourinary abnormalities, but not age, predicted treatment failure.

CONCLUSIONS:

Treatment failure for generally healthy young infants hospitalized with UTIs is uncommon and is not associated with the duration of intravenous antibiotic treatment. Treating more infants with short courses of intravenous antibiotic therapy might decrease resource use without affecting readmission rates.
Investigation of Posttraumatic Stress Disorder in Children After Animal-Induced Injury in China
Authors: Ji Li , Xiaowei Zhang , Chuanlin Wang , Wei Liu
Published: July 2010

OBJECTIVE:

Dogs are important members of many families in many countries. However, posttraumatic stress disorder (PTSD) in children after animal attacks has always been underestimated, and a more-detailed study of PTSD in children after animal attacks is needed.

METHODS:

The charts and follow-up data for 358 children after animal-induced injuries were reviewed. Family Apgar Scale assessment and PTSD screening were performed at emergency department admission. On week 1 after the emergency department admission, the patient underwent evaluation for acute stress disorder (ASD) diagnosis, by using the Child Acute Stress Questionnaire. PTSD screening and interim history-taking were performed 3 months after the emergency department admission, by telephone or in face-to-face interviews, by using the Clinician-Administered PTSD Scale for Children and Adolescents. P values of <.05 were considered significant.

RESULTS:

A total of 19 patients developed PTSD, including 10 patients with severe injuries, 8 patients with moderate injuries, and 1 patient with a mild injury (χ2=48.104; P=.000). No significant differences in PTSD occurrence according to gender and age were observed. Family Apgar Scale scores were not significantly related to PTSD (P=.781). ASD and PTSD symptom severity scores were significantly associated (r=0.51; P < .005).

CONCLUSIONS:

Child victims of severe animal attacks should be considered at risk for the development of PTSD, family support was not correlated with posttraumatic stress symptoms in school-aged children after animal attacks, and ASD seems to be an early predictive indicator of PTSD.
Three-Pass Depletion Sampling Accuracy of Two Electric Fields for Estimating Trout Abundance in a Low-Conductivity Stream with Limited Habitat Complexity
Authors: Habera James W. , Kulp Matt A. , Moore Stephen E. , Henry Theodore B.
Published: July 2010

We evaluated three-pass depletion sampling for both AC and pulsed-DC electrofishing for estimating the population size of rainbow trout Oncorhynchus mykiss in a representative low-conductivity (20-μS/cm) southern Appalachian stream with limited habitat complexity. Trout capture efficiencies in such streams could be expected to exceed those observed in streams in which habitat is more complex; thus, depletion estimates could be much more accurate in the former. We also compared the results for two trout length-groups to investigate size-related differences. Measured capture efficiency was 0.88 ± 0.04 (95% confidence interval) for trout greater than 100 mm (typically adults) and 0.65 ± 0.09 for trout less than 100 mm (age 0). Population size was underestimated in each depletion sample. The errors for trout over 100 mm were generally small (mean, 12%; range, 3–23%), and the upper 95% confidence limits were usually within 10% of the true population size (N). Underestimates of N were larger for trout under 100 mm (mean, 32%; range, 5–60%), although the upper 95% confidence limits were within 20% of the N for half of the samples. The results of a laboratory study confirmed that trout over 100 mm were immobilized at significantly lower voltage gradients than were smaller trout in both electric fields. We conclude that three-pass depletion sampling is relatively accurate in typical southern Appalachian trout streams and that the underestimation errors for rainbow trout larger than 100 mm would be acceptable given basic inventory and monitoring goals.
Biases with the Regression Line Percentile Method and the Fallacy of a Single Standard Weight
Authors: Gerow Kenneth G.
Published: July 2010

The regression line percentile (RLP) method for computing standard weight (Ws) equations produces third-quartile estimates that tend to be biased downward for long fish as a result of extrapolation acting in concert with systematic variation in the distribution of length–weight relationships among fish populations. Parameter mismatch in the development and use of Ws equations (i.e., third quartile for development of Ws equations and use of mean relative weight Wr for application and testing) induces artifactual biases when testing equations and leads to the appearance of reduced fish condition when applied to longer fish. Consistent interpretation of mean Wr against a single standard (e.g., third quartile, median, or any other) is not usually possible due to nonconstant variation in the distributions of mean Wr among species and among length-classes for a given species. I recommend that future computations of Ws use quadratic equations for all three quartiles to enable consistent and more informative interpretation of mean Wr.
Lake Trout Population Dynamics in the Northern Refuge of Lake Michigan: Implications for Future Rehabilitation
Authors: Madenjian Charles P. , Desorcie Timothy J.
Published: July 2010

The Northern Refuge was established in 1985 as part of the lake trout Salvelinus namaycush rehabilitation effort for Lake Michigan. To evaluate progress toward lake trout rehabilitation in the Northern Refuge, we conducted annual (1991–2008) gill-net surveys in the fall to assess the adult population and beam trawl surveys in the spring to assess naturally reproduced age-0 lake trout. Our criteria for evaluating progress included the density of “wild” age-0 fish within the Northern Refuge, the proportion of wild fish within the adult population, density of spawners, adult survival, growth, and wounding rate by sea lampreys Petromyzon marinus. No wild age-0 lake trout were caught in the Northern Refuge during 1991–2008. Overall, wild lake trout did not recruit to the adult population to any detectable degree. The mean density of spawning lake trout decreased from 45 fish·305 m of gill net−1·d−1 during 1991–1999 to only 4 fish·305 m−1·d−1 during 2000–2008. Although the sea lamprey wounding rate more than doubled between these two time periods, catch curve analysis revealed that mortality of adult lake trout actually decreased between the two periods. Therefore, the 90% decrease in abundance of spawning lake trout between the two periods could not be attributed to increased sea lamprey predation but instead was probably due in part to the reduced lake trout stocking rate during 1995–2005. The paucity of natural reproduction in the Northern Refuge during 1991–2008 most likely resulted from alewife Alosa pseudoharengus interference with lake trout reproduction and from the relatively low lake trout spawner density during 2000–2008. Our results suggest that the annual stocking rate of lake trout yearlings should be increased to at least 250,000 fish/reef to achieve greater densities of spawners.
Channel Morphology Response to Selective Wood Removals in a Sand-Laden Wisconsin Trout Stream
Authors: Dumke Joshua D. , Hrabik Thomas R. , Brady Valerie J. , Gran Karen B. , Regal Ronald R. , Seider Michael J.
Published: July 2010

Large sand bed loads in trout stream headwaters can limit salmonid spawning habitat and reproductive success. This phenomenon has been observed in many northern Wisconsin watersheds, where historic logging practices are the likely source of the sediment loading. Presently, sediment transport is limited by abundant woody debris, causing channels to aggrade and bury gravels. We evaluated the impacts of a wood debris and beaver dam removal remediation strategy on fine sediment transport and exposure of the underlying gravel and cobble substrates in a second-order Lake Superior tributary. A 300-m treatment reach received selective wood removals and was compared with both an upstream 300-m reference reach receiving no alteration and a downstream reach to monitor the effects of transferred fine sediment. Physical channel measurements were taken before the wood removal process, with repeat sampling at 10 and 12 months posttreatment. The wood removal treatment resulted in a significant 25% narrowing of mean stream widths, a 32% increase in mean flow velocities, a 58% reduction in the sand bed load, and a 400% increase in the available coarse substrate across the channel. Grain size distributions coarsened noticeably from pre- to posttreatment. Water depth and temperature were not altered by the treatment, and the reference station physical measures were relatively unchanged over the 12-month study period. Immediately after the wood removal there was an observable pulse of sediment traveling through the downstream reach that increased the sand bed load, increased stream widths, and filled pools. However, these impacts diminished with time, and near-preremoval conditions had returned after 12 months. The wood removal treatment caused a significant reduction in sand content and enhanced the availability of salmonid spawning substrates.
Investigating Interactions between Channel Catfish and other Sport Fishes in Small Impoundments
Authors: Leonard D. Michael , DeVries Dennis R. , Wright Russell A.
Published: July 2010

The channel catfish Ictalurus punctatus is a popular sport fish commonly maintained by annual stocking in small impoundments. We sought to determine whether channel catfish negatively affect two other sport fishes (bluegill Lepomis macrochirus and largemouth bass Micropterus salmoides) in Alabama's state public fishing lakes (ASPF lakes) through competition or predation. Using a variety of gears, we sampled channel catfish, largemouth bass, and bluegills in 12 ASPF lakes with variable channel catfish stocking and harvest rates. Four of these lakes were sampled more intensively to quantify the diets of these three species. Bioenergetics simulations were used to predict the annual consumption of channel catfish and largemouth bass populations of average density, size structure, and growth from these impoundments. Metrics of growth, condition, abundance, and population structure were not related between species. Latitude was negatively related to channel catfish growth. The diets of channel catfish and bluegills were moderately similar across all seasons in all lakes, while those of channel catfish and largemouth bass were highly dissimilar. Within species, diet similarity was high among lakes. Bioenergetics simulations suggest that the channel catfish populations in these lakes consume relatively little fish, particularly when compared with a typical largemouth bass population. We found little evidence of negative effects of channel catfish on the bluegill and largemouth bass populations in ASPF lakes, although largemouth bass growth and condition were poorest in the lake with the highest channel catfish stocking rate. However, current stocking and exploitation rates in most lakes appear to maintain channel catfish abundance below the level at which negative effects may occur.
When Conventional Fisheries Management Fails to Reduce the Catch and Discard of Juvenile Fish: A Case Study of the Argentine Hake Trawl Fishery in San Matías Gulf
Authors: Romero M. Alejandra , González Raúl A. , Ocampo-Reinaldo Matías
Published: July 2010

The performance of management measures adopted to reduce the catch of small-size fish in trawl fisheries requires a proper evaluation taking into account that different factors (e.g., the behavior of fishermen, gear efficiency, market forces, and weak controls) may affect the results. The high bycatch of juvenile Argentine hake Merluccius hubbsi recorded in the trawl fishery of San Matías Gulf, Argentina, could be an indication of a suboptimal harvesting pattern that should be addressed. Regulations to mitigate this problem (i.e., a minimum mesh size and the seasonal closure of a nursery area) were imposed in 1997–1998. The purpose of this study was to assess the efficacy of the size-selectivity measure 10 years after its implementation based on two key indicators: the presence of juvenile Argentine hake in catches and discard rates. Our results show that this measure was ineffective in reducing the catch and discard of juveniles and that both indicator values increased during the period analyzed. This failure could be the result of the limited scientific advice available when the measure was designed or poor implementation, monitoring, and control strategies.
Assessment of Hatchery-Reared Pallid Sturgeon Survival in the Lower Missouri River
Authors: Steffensen Kirk D. , Powell Larkin A. , Koch Jeff D.
Published: July 2010

The population of pallid sturgeon Scaphirhynchus albus in the lower Missouri River between Gavins Point Dam (river kilometer [rkm] 1,305.2) and the confluence with the Mississippi River (rkm 0.0) remains imperiled, little to no natural recruitment occurring. Artificial propagation and subsequent population augmentation (i.e., stocking) may be the only viable option for maintaining pallid sturgeon populations in the lower Missouri River in the near term. Because relatively little is known about the ability of hatchery-reared pallid sturgeon to survive, the objective of this study was to quantify survival estimates for hatchery-reared pallid sturgeon stocked into the lower Missouri River. We used stock–recapture data collected from 1994 to 2008 to derive survival estimates based on the Cormack–Jolly–Seber model within program MARK. Since 1994, a total of 78,244 hatchery-reared pallid sturgeon have been released and 1% of these have been recaptured. Recapture numbers by size at stocking were as follows: 48 age 0, 730 age 1, and 38 older than age 1. Stocked age-0 hatchery-reared pallid sturgeon had an estimated apparent survival rate of 0.051 (SE = 0.008), compared with 0.686 (SE = 0.117) for age-1 fish and 0.922 (SE = 0.015) for fish older than age 1. Our analysis confirms that hatchery-reared pallid sturgeon can survive in the wild and contribute to the overall population of this species. These estimates should provide critical information for decisions regarding stocking strategies within the lower Missouri River and enable biologists to estimate the number of stocked pallid sturgeon that reach sexual maturity.
Injury and Mortality of Juvenile Salmon Entrained in a Submerged Jet Entering Still Water
Authors: Deng Zhiqun , Mueller Robert P. , Richmond Marshall C. , Johnson Gary E.
Published: July 2010

Development of more eco-friendly hydroelectric facilities requires better understanding of the biological response of juvenile fish when they migrate through the turbines and other downstream passage facilities. Juvenile fall Chinook salmon Oncorhynchus tshawytscha were exposed to turbulent shear flows in a laboratory by using a fast-fish-to-slow-water mechanism in which test fish were carried by the fast-moving water of a submerged turbulent jet into the slow-moving water of a flume. Fish were released at six nozzle velocities: 6.1 (reference control), 12.2, 15.2, 18.3, 21.3, and 22.9 m/s. The onset of minor and major injuries occurred at 15.2 and 21.3 m/s, respectively. The acceleration magnitude threshold (m/s2) of major injury for the fast-fish-to-slow-water mechanism in this study was found to be significantly higher than that for a slow-fish-to-fast-water mechanism used in a previous study in which test fish were introduced into a turbulent jet from slow-moving water through an introduction tube placed just outside the edge of the jet. Fish responded differently and sustained different injuries when they were subjected to turbulent shear flows under the two exposure mechanisms. This information is applicable to the design and operation of turbines and spillways because these two tested mechanisms simulate the severe hydraulic events fish usually experience during passage at hydropower dams.
Sex Ratios of Black Crappies Harvested during Spring Fisheries on Two Minnesota Lakes: Are Males in the Majority?
Authors: Isermann Daniel A. , Schultz Douglas W. , Carlson Andrew J.
Published: July 2010

Sex-selective fishing mortality can alter the demographics and life history patterns of fish populations, yet the extent of this mortality is rarely investigated in harvest-oriented recreational fisheries. Potential differences in habitat use between sexes and nest-guarding behavior suggest that male black crappies Pomoxis nigromaculatus could dominate angler harvest during spring fisheries. We examined the potential for male-dominated harvest in spring (late April to mid-June) recreational fisheries for black crappies occurring on two north-central Minnesota lakes. In the three spring fisheries we examined, males represented between 45% and 57% of all black crappies harvested by anglers, but sex ratios (expressed as the percentages of males) did not significantly deviate from 1:1. However, a temporal pattern in sex ratios was observed on Lake Hubert, where female black crappies dominated angler harvest before 19 May in both 2005 and 2006 (41–42% male) while the harvest on or after 19 May was dominated by males (69–75% male); this shift appeared to coincide with peak nesting periods. In fall electrofishing samples, the sex ratios of black crappies that had been exposed to exploitation during spring fisheries (i.e., fish age 4 and older) did not significantly deviate from 1:1, suggesting that total annual mortality rates were similar between sexes. The sex ratios of black crappies harvested by anglers during spring can vary within and among lakes and will not always be skewed toward male fish. Estimating population sex ratios and the sex ratio of black crappies harvested by anglers may improve our understanding of the effects of exploitation on crappie populations, particularly when fishing intensity during nesting is high and nests are easily located by anglers.
Influence of Drought Conditions on Brown Trout Biomass and Size Structure in the Black Hills, South Dakota
Authors: James Daniel A. , Wilhite Jerry W. , Chipps Steven R.
Published: July 2010

We evaluated the influence of drought conditions on the biomass of brown trout Salmo trutta in Spearfish Creek, upper Rapid Creek, and lower Rapid Creek in the Black Hills of western South Dakota. Stream discharge, mean summer water temperature, the biomass of juvenile and adult brown trout, and brown trout size structure were compared between two time periods: early (2000–2002) and late drought (2005–2007). Mean summer water temperatures were similar between the early- and late-drought periods in Spearfish Creek (12.4°C versus 11.5°C), lower Rapid Creek (19.2°C versus 19.3°C), and upper Rapid Creek (9.8°C in both periods). In contrast, mean annual discharge differed significantly between the two time periods in Spearfish Creek (1.95 versus 1.50 m3/s), lower Rapid Creek (2.01 versus 0.94 m3/s), and upper Rapid Creek (1.41 versus 0.84 m3/s). The mean biomass of adult brown trout in all three stream sections was significantly higher in the early-drought than in the late-drought period (238 versus 69 kg/ha in Spearfish Creek, 272 versus 91 kg/ha in lower Rapid Creek, and 159 versus 32 kg/ha in upper Rapid Creek). The biomass of juvenile brown trout was similar (43 versus 23 kg/ha) in Spearfish Creek in the two periods, declined from 136 to 45 kg/ha in lower Rapid Creek, and increased from 14 to 73 kg/ha in upper Rapid Creek. Size structure did not differ between the early- and late-drought periods in lower Rapid and Spearfish creeks, but it did in upper Rapid Creek. In addition to drought conditions, factors such as angler harvest, fish movements, and the nuisance algal species Didymosphenia geminata are discussed as possible contributors to the observed changes in brown trout biomass and size structure in Black Hills streams.
Evaluation of a Sport Fish Stocking Program in Lakes of the Southern Murray–Darling Basin, Australia
Authors: Hunt Taylor L. , Allen Micheal S. , Douglas John , Gason Anne
Published: July 2010

The golden perch Macquaria ambigua is a recreationally important freshwater sport and food fish species found throughout southeastern Australia. Stocking golden perch in impoundments has been used by fisheries managers to enhance existing wild populations for over 30 years. Despite widespread stocking, the contribution of stocked fish to golden perch populations has not been investigated. We evaluated the stocking contribution by using chemically marked golden perch fingerlings introduced into three lakes in which natural recruitment is low. We surveyed the lakes to determine the contribution of the stocked fish to the lake populations and found an overall contribution of 47 ± 9% (mean ± SE) at Reedy Lake, 55 ± 9% at Kangaroo Lake, and 90 ± 5% at Lake Charm. Our results indicate that, rather than replacing wild fish, stocked fish increased the abundance of adult fish at all three lakes. The contribution of stocked fish to each population declined with increased connectedness to the Loddon River, which served as the probable source for the wild fish population. Stocking programs can substantially augment fish populations when natural recruitment is very low.
Evaluating the Status and Trends of Physical Stream Habitat in Headwater Streams within the Interior Columbia River and Upper Missouri River Basins Using an Index Approach
Authors: Al‐Chokhachy Robert , Roper Brett B. , Archer Eric K.
Published: July 2010

Identifying the overall status of freshwater streams is an important step in evaluating effects of land management and prioritizing restoration activities. To address these needs, we developed an index of physical habitat condition for headwater streams based on physical stream habitat data (2003–2007) and evaluated the condition status of 217 reference streams and 934 managed streams in the interior Columbia River and upper Missouri River basins. We used data collected from reference reaches to generate this index, which consisted of eight commonly collected metrics used in stream habitat monitoring. We incorporated landscape and climatic covariates into multiple linear regression analyses to control for inherent differences in physical habitat attributes among reaches, and we scored the overall condition of reaches with index values ranging from 0 to 100. Our results indicated that the condition index score of physical habitat was significantly higher in reference reaches (mean ± SE = 47.1 ± 1.4) than in managed reaches (30.4 ± 0.7); relative to reference reaches, a greater frequency of managed reaches had low habitat condition and a lower frequency of managed reaches had high habitat condition. Analyses evaluating the relationship between management activities and the condition of physical habitat in streams indicated a significant negative relationship with lower index scores in stream reaches within catchments containing higher densities of roads. When roads and livestock grazing occurred within catchments, we found the presence of grazing had an additional, significant negative effect on the relationship between road density and the condition of physical habitat of streams. Our results suggested that once natural variability and geoclimatic differences among reaches are accounted for, a multimetric index approach can provide managers with an easily interpretable tool to monitor the status of the overall condition of physical habitat.
Avian Piscivores as Vectors forMyxobolus cerebralisin the Greater Yellowstone Ecosystem
Authors: Koel Todd M. , Kerans Billie L. , Barras Scott C. , Hanson Katie C. , Wood John S.
Published: July 2010

Myxobolus cerebralis, the cause of whirling disease in salmonids, has dispersed to waters in 25 states within the USA, often by an unknown vector. Its incidence in Yellowstone cutthroat troutOncorhynchus clarkii bouvieriwithin the highly protected environment of Yellowstone Lake, Yellowstone National Park, is a prime example. Given the local abundances of piscivorous birds, we sought to clarify their potential role in the dissemination ofM. cerebralis. Six individuals from each of three bird species (American white pelicanPelecanus erythrorhynchos, double‐crested cormorantPhalacrocorax auritus, and great blue heronArdea herodias) were fed known‐infected or uninfected rainbow troutO. mykiss. Fecal material produced during 10‐d periods before and after feeding was collected to determine whetherM. cerebraliscould be detected and, if so, whether it remained viable after passage through the gastrointestinal tract of these birds. For all (100%) of the nine birds fed known‐infected fish, fecal samples collected during days 1–4 after feeding tested positive forM. cerebralisby polymerase chain reaction. In addition, tubificid wormsTubifex tubifexthat were fed fecal material from known‐infected great blue herons produced triactinomyxons in laboratory cultures, confirming the persistent viability of the parasite. No triactinomyxons were produced fromT. tubifexfed fecal material from known‐infected American white pelicans or double‐crested cormorants, indicating a potential loss of parasite viability in these species. Great blue herons have the ability to concentrate and release viable myxospores into shallow‐water habitats that are highly suitable forT. tubifex, thereby supporting a positive feedback loop in which the proliferation ofM. cerebralisis enhanced. The presence of avian piscivores as an important component of aquatic ecosystems should continue to be supported. However, given the distances traveled by great blue herons between rookeries and foraging areas in just days, any practices that unnaturally attract them may heighten the probability ofM. cerebralisdispersal and proliferation within the Greater Yellowstone Ecosystem.
Juvenile Salmonid Use of Reconnected Tidal Freshwater Wetlands in Grays River, Lower Columbia River Basin
Authors: Roegner G. Curtis , Dawley Earl W. , Russell Micah , Whiting Allan , Teel David J.
Published: July 2010

Degraded wetland systems with impaired hydraulic connections have resulted in diminished habitat opportunity for salmonid fishes and other native flora and fauna in the Pacific Northwest. Many of these lost habitats were once intertidal freshwater marshes and swamps. Restoration of these systems is effected in part by reestablishing tidal processes that promote connectivity, with a central goal of restoring rearing habitat for juvenile Pacific salmon Oncorhynchus spp. In the Grays River tidal freshwater system of Washington, we measured hydrologic changes that resulted from the removal of tide gates from diked pastureland and we determined the subsequent time series of salmonid abundance and size frequency in the restoring marshes. Dike breaching caused an immediate return of full semidiurnal tidal fluctuations to the pasturelands. Juvenile Pacific salmonids quickly expanded into this newly available habitat and used prey items that were presumably produced within the marshes. Habitat use varied by species and life history stage. Fry of chum salmon O. keta migrated rapidly through the system, whereas populations of Chinook salmon O. tshawytscha and coho salmon O. kisutch resided from March to at least July and were composed of fry, fingerlings, and (for coho salmon) yearlings. Based on salmon size at date and the timing of hatchery releases, we concluded that most salmon sampled in restored and reference sites were the progeny of natural spawners. However, the presence of adipose‐fin‐clipped Chinook salmon indicated that hatchery‐raised fish originating outside the Grays River system also used the restoring wetland habitat. Because of extensive mixing of stocks through hatchery practices, genetic analyses did not provide additional insight into the origins of the Chinook salmon but did reveal that out‐migrating juveniles were an admixed population composed of lower Columbia River ancestry and nonindigenous Rogue River stock. Restoration of tidal wetlands in the Columbia River estuary will improve overall ecosystem connectivity and reduce habitat fragmentation and may therefore increase survival of a variety of Pacific salmon stocks during migration.