bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Less-Abundant Viral MicroRNAs Encoded by Herpes Simplex Virus 2 Latency-Associated Transcript and Their Roles in Regulating ICP34.5 and ICP0 mRNAs
Authors: Tang Shuang , Patel Amita , Krause Philip R.
Published: November 2008

We recently identified an acutely and latently expressed viral microRNA (miRNA), miR-I, encoded by herpes simplex virus 2 (HSV-2) latency-associated transcript (LAT) through small RNA cloning and two miRNAs encoded by HSV-1 LAT through prediction. We now report the use of high-throughput sequencing technology to identify two additional relatively less-abundant viral miRNAs, miR-II and miR-III, encoded by HSV-2 LAT exon 2. miR-II includes two miRNAs, miR-II-5p and miR-II-3p, which are processed from the same miRNA precursor. miR-II and miR-III map antisense to the 5′ untranslated region of ICP34.5 and to the coding region of ICP0 exon 3, respectively. These novel miRNAs are conserved in different HSV-2 strains, and their presence in infected- and transfected-cell cultures was confirmed by Northern hybridization. All three HSV-2 LAT-encoded miRNAs map to genome locations similar to those of three out of four identified HSV-1 LAT-encoded miRNAs, but the sequences of these miRNAs are not conserved. The expression of LAT-encoded miRNAs is negatively regulated by ICP4, the major viral transactivator. We further show that, similar to miR-I, miR-II is able to efficiently silence the expression of ICP34.5, a key viral neurovirulence factor, and that miR-III is able to silence the expression of ICP0, a key viral transactivator. All these data suggest that LAT sequences likely contribute to HSV latency and reactivation through tight control of these LAT-encoded miRNAs and their viral targets.
Human Immunodeficiency Virus Type 2 (HIV-2)/HIV-1 Envelope Chimeras Detect High Titers of Broadly Reactive HIV-1 V3-Specific Antibodies in Human Plasma
Authors: Davis Katie L. , Bibollet-Ruche Frederic , Li Hui , Decker Julie M. , Kutsch Olaf , Morris Lynn , Salomon Aidy , Pinter Abraham , Hoxie James A. , Hahn Beatrice H. , Kwong Peter D. , Shaw George M.
Published: November 2008

Deciphering antibody specificities that constrain human immunodeficiency virus type 1 (HIV-1) envelope (Env) diversity, limit virus replication, and contribute to neutralization breadth and potency is an important goal of current HIV/AIDS vaccine research. Transplantation of discrete HIV-1 neutralizing epitopes into HIV-2 scaffolds may provide a sensitive, biologically functional context by which to quantify specific antibody reactivities even in complex sera. Here, we describe a novel HIV-2 proviral scaffold (pHIV-2KR.X7) into which we substituted the complete variable region 3 (V3) of theenvgene of HIV-1YU2or HIV-1Cconto yield the chimeric proviruses pHIV-2KR.X7YU2 V3 and pHIV-2KR.X7Ccon V3. These HIV-2/HIV-1 chimeras were replication competent and sensitive to selective pharmacological inhibitors of virus entry. V3 chimeric viruses were resistant to neutralization by HIV-1 monoclonal antibodies directed against the CD4 binding site, coreceptor binding site, and gp41 membrane proximal external region but exhibited striking sensitivity to HIV-1 V3-specific monoclonal antibodies, 447-52D and F425 B4e8 (50% inhibitory concentration of [IC50] <0.005 μg/ml for each). Plasma specimens from 11 HIV-1 clade B- and 10 HIV-1 clade C-infected subjects showed no neutralizing activity against HIV-2 but exhibited high-titer V3-specific neutralization against both HIV-2/HIV-1 V3 chimeras with IC50measurements ranging from 1:50 to greater than 1:40,000. Neutralization titers of B clade plasmas were as much as 1,000-fold lower when tested against the primary HIV-1YU2virus than with the HIV-2KR.X7YU2 V3 chimera, demonstrating highly effective shielding of V3 epitopes in the native Env trimer. This finding was replicated using a second primary HIV-1 strain (HIV-1BORI) and the corresponding HIV-2KR.X7BORI V3 chimera. We conclude that V3 is highly immunogenic in vivo, eliciting antibodies with substantial breadth of reactivity and neutralizing potential. These antibodies constrain HIV-1 Env to a structure(s) in which V3 epitopes are concealed prior to CD4 engagement but do not otherwise contribute to neutralization breadth and potency against most primary virus strains. Triggering of the viral spike to reveal V3 epitopes may be required if V3 immunogens are to be components of an effective HIV-1 vaccine.
Vaccinia Virus Extracellular Enveloped Virion Neutralization In Vitro and Protection In Vivo Depend on Complement
Authors: Benhnia Mohammed Rafii-El-Idrissi , McCausland Megan M. , Moyron Juan , Laudenslager John , Granger Steven , Rickert Sandra , Koriazova Lilia , Kubo Ralph , Kato Shinichiro , Crotty Shane
Published: November 2008

Antibody neutralization is an important component of protective immunity against vaccinia virus (VACV). Two distinct virion forms, mature virion and enveloped virion (MV and EV, respectively), possess separate functions and nonoverlapping immunological properties. In this study we examined the mechanics of EV neutralization, focusing on EV protein B5 (also called B5R). We show that neutralization of EV is predominantly complement dependent. From a panel of high-affinity anti-B5 monoclonal antibodies (MAbs), the only potent neutralizer in vitro (90% at 535 ng/ml) was an immunoglobulin G2a (IgG2a), and neutralization was complement mediated. This MAb was the most protective in vivo against lethal intranasal VACV challenge. Further studies demonstrated that in vivo depletion of complement caused a >50% loss of anti-B5 IgG2a protection, directly establishing the importance of complement for protection against the EV form. However, the mechanism of protection is not sterilizing immunity via elimination of the inoculum as the viral inoculum consisted of a purified MV form. The prevention of illness in vivo indicated rapid control of infection. We further demonstrate that antibody-mediated killing of VACV-infected cells expressing surface B5 is a second protective mechanism provided by complement-fixing anti-B5 IgG. Cell killing was very efficient, and this effector function was highly isotype specific. These results indicate that anti-B5 antibody-directed cell lysis via complement is a powerful mechanism for clearance of infected cells, keeping poxvirus-infected cells from being invisible to humoral immune responses. These findings highlight the importance of multiple mechanisms of antibody-mediated protection against VACV and point to key immunobiological differences between MVs and EVs that impact the outcome of infection.
Hepatitis C Virus Neuroinvasion: Identification of Infected Cells
Authors: Wilkinson Jeffrey , Radkowski Marek , Laskus Tomasz
Published: November 2008

Hepatitis C virus (HCV) infection often is associated with cognitive dysfunction and depression. HCV sequences and replicative forms were detected in autopsy brain tissue and cerebrospinal fluid from infected patients, suggesting direct neuroinvasion. However, the phenotype of cells harboring HCV in brain remains unclear. We studied autopsy brain tissue from 12 HCV-infected patients, 6 of whom were coinfected with human immunodeficiency virus. Cryostat sections of frontal cortex and subcortical white matter were stained with monoclonal antibodies specific for microglia/macrophages (CD68), oligodendrocytes (2′,3′-cyclic nucleotide 3′-phosphodiesterase), astrocytes (glial fibrillary acidic protein [GFAP]), and neurons (neuronal-specific nuclear protein); separated by laser capture microscopy (LCM); and tested for the presence of positive- and negative-strand HCV RNA. Sections also were stained with antibodies to viral nonstructural protein 3 (NS3), separated by LCM, and phenotyped by real-time PCR. Finally, sections were double stained with antibodies specific for the cell phenotype and HCV NS3. HCV RNA was detected in CD68-positive cells in eight patients, and negative-strand HCV RNA, which is a viral replicative form, was found in three of these patients. HCV RNA also was found in astrocytes from three patients, but negative-strand RNA was not detected in these cells. In double immunostaining, 83 to 95% of cells positive for HCV NS3 also were CD68 positive, while 4 to 29% were GFAP positive. NS3-positive cells were negative for neuron and oligodendrocyte phenotypic markers. In conclusion, HCV infects brain microglia/macrophages and, to a lesser extent, astrocytes. Our findings could explain the biological basis of neurocognitive abnormalities in HCV infection.
Efficient Nuclear Export of Herpes Simplex Virus 1 Transcripts Requires both RNA Binding by ICP27 and ICP27 Interaction with TAP/NXF1
Authors: Johnson Lisa A. , Sandri-Goldin Rozanne M.
Published: November 2008

Herpes simplex virus 1 (HSV-1) regulatory protein ICP27 has been reported to bind viral RNA and to interact with the nuclear export adaptor Aly/REF and the major cellular mRNA nuclear export receptor TAP/NXF1. Using in situ hybridization and in vitro export assays, we show here that poly(A)
+
RNA was retained in the nucleus of cells infected with viral ICP27 mutants that either cannot bind RNA or that do not interact with TAP/NXF1. Microarray analysis of nuclear and cytoplasmic RNA fractions demonstrated that efficient export of the majority of viral transcripts requires that ICP27 be able to bind RNA and to interact with TAP/NXF1. We conclude that ICP27 is the major export adaptor for HSV-1 mRNA and that it links bound transcripts to the TAP/NXF1 export receptor.
The C-Terminal Domain of ERp29 Mediates Polyomavirus Binding, Unfolding, and Infection
Authors: Rainey-Barger Emily K. , Mkrtchian Souren , Tsai Billy
Published: November 2008

Penetration of the endoplasmic reticulum (ER) membrane by polyomavirus (PyV) is a decisive step in virus entry. We showed previously that the ER-resident factor ERp29 induces the local unfolding of PyV to initiate the ER membrane penetration process. ERp29 contains an N-terminal thioredoxin domain (NTD) that mediates its dimerization and a novel C-terminal all-helical domain (CTD) whose function is unclear. The NTD-mediated dimerization of ERp29 is critical for its unfolding activity; whether the CTD plays any role in PyV unfolding is unknown. We now show that three hydrophobic residues within the last helix of the ERp29 CTD that were individually mutated to either lysine or alanine abolished ERp29's ability to stimulate PyV unfolding and infection. This effect was not due to global misfolding of the mutant proteins, as they dimerize and do not form aggregates or display increased protease sensitivity. Moreover, the mutant proteins stimulated secretion of the secretory protein thyroglobulin with an efficiency similar to that of wild-type ERp29. Using a cross-linking coimmunoprecipitation assay, we found that the physical interaction of the ERp29 CTD mutants with PyV is inefficient. Our data thus demonstrate that the ERp29 CTD plays a crucial role in PyV unfolding and infection, likely by serving as part of a substrate-binding domain.
In Vivo Fitness Cost of the M184V Mutation in Multidrug-Resistant Human Immunodeficiency Virus Type 1 in the Absence of Lamivudine
Authors: Paredes Roger , Sagar Manish , Marconi Vincent C. , Hoh Rebecca , Martin Jeffrey N. , Parkin Neil T. , Petropoulos Christos J. , Deeks Steven G. , Kuritzkes Daniel R.
Published: November 2008

Lamivudine therapy selects for the M184V mutation. Although this mutation reduces the replicative capacity of human immunodeficiency virus in vitro, its impact on viral fitness in vivo has not been well defined. We used quantitative allele-specific PCR to precisely calculate the fitness differences between the mutated M184V virus and one that had reverted to the wild type in a cohort of patients by selectively interrupting reverse transcriptase inhibitor therapy, and we found that the M184V variants were consistently 4 to 8% less fit than the wild type in the absence of drug. After a lag phase of variable duration, wild-type variants emerged due to continued evolution of
pol
and back mutation rather than through emergence of an archived wild-type variant.
Inhibitory effect of rapamycin and dexamethasone on production of IL-17 and IFN-γ in Vogt–Koyanagi–Harada patients
Authors: Yang K , Wen J , Liu X , Kijlstra A , Chen L , Chi W , Zhou H , Huang X , Yang P
Published: November 2008

Aims:

To evaluate the effect of rapamycin (RAPA) and dexamethasone (DEX) on the production of IL-17 and IFN-γ by peripheral blood mononuclear cells (PBMCs) from Vogt–Koyanagi–Harada (VKH) patients and healthy individuals.

Methods:

Blood samples were drawn from 10 active VKH patients and 10 healthy individuals. PBMCs were cultured with or without anti-CD3 and anti-CD28 antibodies in the presence or absence of different concentrations of RAPA or DEX for 72 h. IL-17 and IFN-γ concentrations in the supernatants were measured by enzyme-linked immunosorbent assay (ELISA).

Results:

The expression of IL-17 and IFN-γ was significantly increased in active VKH patients compared with that in healthy controls. Both RAPA and DEX were able to significantly inhibit the production of IL-17 and IFN-γ by PBMCs from patients and healthy controls. RAPA was able to completely inhibit IL-17 production at a dosage of 10 ng/ml but only partially suppressed IFN-γ production even at a much higher concentration (1000 ng/ml). DEX inhibited the production of both IL-17 and IFN-γ by approximately 70%.

Conclusions:

This study indicates that both RAPA and DEX inhibit the production of IL-17 and IFN-γ by PBMCs. RAPA is much stronger in inhibiting the production of IL-17 than DEX.
Predictive index to differentiate invasive squamous cell carcinoma from preinvasive ocular surface lesions by impression cytology
Authors: Barros J N , Lowen M S , Ballalai P L , Mascaro V L D M , Gomes J Á P , Martins M C
Published: November 2008

Background/aims:

In the literature, no cytological features have been identified that reliably differentiate invasive squamous cell carcinoma (SCC) from preinvasive lesions in impression cytology (IC) samples. The aim was to identify cytological features related to malignancy and apply them in a quantitative model to determine an index score with the best predictive power to differentiate SCC from preinvasive ocular surface lesions by IC.

Methods:

39 patients with ocular surface epithelial lesions were enrolled. IC was obtained from all lesions before surgical excision. Specimens with atypical cells were evaluated regarding 11 cytological parameters based on the 2001 Bethesda system.

Results:

Histopathological diagnosis was pterygium in one case, actinic keratosis in nine cases, intraepithelial neoplasia in nine cases and SCC in 20 cases. Analysis of the receiver operating characteristic curve revealed that a predictive index score (cut-off point) ⩾4.25 presented the best relationship between sensitivity and specificity in identifying SCC (sensitivity of 95%, specificity of 93%, positive predictive value of 95% and negative predictive value of 93%).

Conclusion:

The scoring system model presented is suitable for clinical practice in differentiating SCC from preinvasive ocular surface lesions by IC and can be better evaluated with prospective use.
A prospective study of punch biomechanics and cognitive function for amateur boxers
Authors: Stojsih S , Boitano M , Wilhelm M , Bir C
Published: November 2008

Objective

To evaluate several biomechanical factors of the head during a sparring session and their link to cognitive function.

Design

Instrumented Boxing Headgear (IBH) was used for data collection during four 2 min sparring sessions. Neurocognitive assessment was measured using the ImPACT© Concussion management software. A baseline neurocognitive test was obtained from each athlete prior to sparring; two additional tests were obtained and compared with the baseline.

Setting

Male and female amateur boxers.

Participants

Data were collected from 30 male and 30 female amateur boxers.

Main outcome measurements

Head accelerations (translational and rotational), injury severity indexes (Head Injury Criteria (HIC) and Gadd Severity Index (GSI)) and cognitive function scores.

Results

Peak translational and rotational acceleration values were 191gand 17 156 rad/s2, respectively, for males and 184gand 13 113 rad/s2, respectively, for females. The peak HIC and GSI values for males were 1652 and 2292, respectively, and for females 1079 and 1487, respectively. There was no significant difference in the neurocognitive scores between genders. A decrease was exhibited in the delayed memory postbout scores. All other scores either increased or did not significantly decrease when compared with the baseline.

Conclusions

The majority of impacts experienced by both genders were under the threshold for mild head injury. There was a statistically significant difference between peak translational and rotational acceleration, HIC and GSI when comparing genders. When analysing cognitive functions, there was no statistical difference between genders.
Is tai chi beneficial for improving aerobic capacity? A systematic review
Authors: Lee M S , Lee E-N , Ernst E
Published: November 2008

Tai chi has been claimed to generate beneficial effects with respect to a wide range of diseases. The purpose of this systematic review was to evaluate evidence from randomised clinical trials (RCTs) testing the effectiveness of tai chi for increasing aerobic capacity. Systematic searches were conducted on 14 electronic databases without restrictions on population characteristics or the language of publication. The outcome measures considered for inclusion were changes in maximal oxygen consumption as a test for aerobic capacity. Five RCTs met all inclusion criteria. Three RCTs compared the effects of tai chi with no treatment. The meta-analysis failed to show an effect of tai chi on aerobic capacity compared with sedentary controls (n = 151, weight mean difference, ml/kg/min, 0.50, 95% CI −1.14 to 2.15, p = 0.55). Two RCTs compared tai chi with conventional physical exercise including brisk, low intensity and moderate intensity walking, and aerobic exercise. The results show that tai chi was not statistically significantly superior to physical exercise. In conclusion, the existing evidence does not suggest that regular tai chi is an effective way of increasing aerobic capacity.
The effects of acute dynamic exercise on haemostasis in first class Scottish football referees
Authors: Peat E E , Dawson M , McKenzie A , Hillis W S
Published: November 2008

Purpose

Physical fitness may confer protection from thrombosis; however, exercise-induced platelet activation may be involved in the triggering of acute vascular events. This study aimed to assess haemostatic responses to acute exercise in trained and sedentary middle-aged subjects.

Methods

21 first class Scottish football referees and 15 sedentary controls performed a treadmill exercise test. Blood sampling was performed before, immediately after and 30 minutes post-exercise. Samples were analysed for platelet count, prothrombin time, activated partial thromboplastin time (APTT) and serum fibrinogen. Platelet activation was assessed using flow cytometry with CD62 (P-selectin) and antifibrinogen antibodies at rest and in response to ADP and epinephrine.

Results

Mean maximal oxygen consumption (Vo2) (ml/kg per minute) achieved was 47.23 (5.02) in the referees and 30.1 (5.2) in sedentary controls. Total platelet count (×10−9/l) increased immediately post-exercise (228.2 (40.5), 278.6 (48.9) p=0.001) remaining elevated at 30 minutes in both groups. APTT (s) was reduced immediately post-exercise (32.15 (3.1), 29.7 (3.94) p=0.001) with a further reduction seen at 30 minutes (32.15 (3.1), 28.4 (3.31) p=0.001). In the referees, percentage CD62 expression increased immediately post-exercise (0.688 (0.52), 1.42 (1.3) p=0.008). Percentage antifibrinogen expression increased post-exercise (5.19 (4.31), 13.01 (14.24) p=0.017), with a further increase at 30 minutes (5.19 (4.31), 20.47 (26.8) p=0.02). Similar trends were seen in sedentary controls.

Conclusion

This study suggests that in an older athletic population, physical fitness does not protect against the prothrombotic effects of exercise. These data suggest that during a football match when referees achieve approximately 80% of peak Vo2(23) they may be at risk of significant platelet activation. Prophylactic platelet inhibition should be considered in this group after appropriate screening and risk stratification.
Promoting physical activity in children: the stepwise development of the primary school-based JUMP-in intervention applying the RE-AIM evaluation framework
Authors: De Meij J S B , Chinapaw M J M , Kremers S P J , Van der wal M F , Jurg M E , Van Mechelen W
Published: November 2008

Background

There is a lack of effective intervention strategies that promote physical activity (PA) in school children. Furthermore, there is a gap between PA intervention research and the delivery of programmes in practice. Evaluation studies seldom lead to adaptations in interventions that are subsequently evaluated by implementation on a wider scale. The stepwise development and study of JUMP-in aims to add knowledge to better understand how, when and for whom intervention effects (or lack of effects) occur.

Methods

This paper describes the stepwise development of JUMP-in, a Dutch school-based multi-level intervention programme, aimed at the promotion of PA behaviour in 6–12-year-old children. JUMP-in incorporates education, sports, care and policy components. JUMP-in consists of six programme components:

Pupil Follow-up Monitoring System;

School sports clubs;

In-class exercises with “The Class Moves!”;

Personal workbook “This is the way you move!”;

Parental Information Services;

Extra lessons in physical education, Motor Remedial

Teaching and extra care.

The process and effect outcomes of a pilot study were translated into an improved programme and intervention organisation, using the RE-AIM framework (Reach, Efficacy, Adoption, Implementation and Maintenance).

This paper presents the process and results of the application of this framework, which resulted in a widescale implementation of JUMP-in.

Results

The application of the RE-AIM framework resulted in challenges and remedies for an improved JUMP-in intervention. The remedies required changes at three different levels: (1) the content of the programme components; (2) the organisation and programme management; and (3) the evaluation design.

Conclusions

Considering factors that determine the impact of PA interventions in ‘real life’ is of great importance. The RE-AIM framework appeared to be a useful guide by which process and effect outcomes could be translated into an improved programme content and organisation.
Exercise and cognition in older adults: is there a role for resistance training programmes?
Authors: Liu-Ambrose T , Donaldson M G
Published: November 2008

In recent years, there has been a strong interest in physical activity as a primary behavioural prevention strategy against cognitive decline. A number of large prospective cohort studies have highlighted the protective role of regular physical activity in lowering the risk of cognitive impairment and dementia. Most prospective intervention studies of exercise and cognition to date have focused on aerobic-based exercise training. These studies highlight that aerobic-based exercise training enhances both brain structure and function. However, it has been suggested that other types of exercise training, such as resistance training, may also benefit cognition. The purpose of this brief review is to examine the evidence regarding resistance training and cognitive benefits. Three recent randomised exercise trials involving resistance training among seniors provide evidence that resistance training may have cognitive benefits. Resistance training may prevent cognitive decline among seniors via mechanisms involving insulin-like growth factor I and homocysteine. A side benefit of resistance training, albeit a very important one, is its established role in reducing morbidity among seniors. Resistance training specifically moderates the development of sarcopenia. The multifactorial deleterious sequelae of sarcopenia include increased falls and fracture risk as well as physical disability. Thus, clinicians should consider encouraging their clients to undertake both aerobic-based exercise training and resistance training not only for “physical health” but also because of the almost certain benefits for “brain health”.
Ion Flux Rates, Acid–Base Status, and Blood Gases in Rainbow Trout,Salmo gairdneri, Exposed to Toxic Zinc in Natural Soft Water
Authors: Spry Douglas J. , Wood Chris M.
Published: November 2008

Exposure to 0.8 mg Zn2+/L in natural soft water for up to 72 h was toxic to rainbow trout, Salmo gairdneri, causing an acid–base disturbance and net branchial ion losses. Mean arterial pH fell from 7.78 to 7.58. Both [Formula: see text] and lactate rose, indicating a mixed respiratory and metabolic acidosis, despite maintenance of high [Formula: see text] Net branchial uptake of Na+and Cl−became a net loss immediately following exposure to Zn2+, and this continued during 60 h of exposure. Net K+loss was exacerbated, and net Ca2+uptake was abolished. Unidirectional flux measurements with22Na+and36Cl−indicated an increased efflux immediately following zinc exposure. Both influx and efflux of Na+and Cl−were stimulated after 48–60 h in Zn2+. Both net branchial ammonia excretion and net branchial uptake of acidic equivalents from the water (=base loss) were greatly stimulated, the latter contributing to metabolic acidosis. Kidney function, as measured by urine flow rate and excretion of ammonia, acidic equivalents, Na+, Cl−, K+, and Zn2+, was relatively insensitive to the effects of zinc. The only renal component to be affected was Ca2+excretion, which decreased during a single flux period, possibly in response to the reduced entry of Ca2+at the gill. We conclude that toxic concentrations of zinc are capable of altering gill function so as to cause ionoregulatory and acid–base disturbances without disturbance of [Formula: see text].
Resource Partitioning and Niche Shifts of Bream (Abramis brama) and Eel (Anguilla anguilla) Mediated by Predation of Smelt (Osmerus eperlanus) on Daphnia hyalina
Authors: Lammens Eddy H. R. R. , Nie Henrik W. de , Vijverberg Jacobus , Densen Wim L T. van
Published: November 2008

The resource partitioning of the bream (Abramis brama) and eel (Anguilla anguilla) populations in Lake Tjeukemeer, The Netherlands, was related to the variation in abundance of their most important food organisms, Daphnia hyalina and larval chironomids. Niche shifts of both bream and eel populations were related to the abundance of young planktivorous fish, particularly smelt (Osmerus eperlanus). When these fish were abundant the D. hyalina population was dominated by small individuals and bream switched from a planktivorous to a benthivorous diet, the condition of mature bream deteriorated, and its gonads developed poorly. Under these circumstances the eel population switched from a diet of chironomid pupae and molluscs to one of predominantly fish. The condition of eels smaller than 35 cm decreased and the chironomid population decreased in numbers and biomass. Conversely, when the recruitment of planktivorous fish was poor, the size of D. hyalina was large and diets and conditions of bream and eel populations changed again. Because of the hydrological regime the stock of the young planktivorous fish is determined to a great extent by the immigration of allochthonous larval smelt and varies markedly, but the biomass of the bream and eel populations is comparatively stable.
Tidal Exchange of Anadromous Rainbow Smelt (Osmerus mordax) Larvae Between a Shallow Spawning Tributary and the St, Lawrence Estuary
Authors: Ouellet Patrick , Dodson Julian J.
Published: November 2008

The factors involved in the riverine transport and tidal exchange of yolk-sac rainbow smelt (Osmerus mordax) larvae between Ouelle River and the St. Lawrence estuary were documented. A 72-h sampling series provided evidence of synchronous nighttime hatching of larvae independent of water temperature and river hydrodynamics. Although light conditions influence the vertical distribution of yolk-sac larvae at the river's mouth, the influence of current speed on larval vertical distribution appears to be a more important element in the dynamics of riverine drift and tidal exchange. Yolk-sac larvae sink to the bottom as water currents decrease prior to low slack water. With the intrusion of estuarine water along the bottom during the flood, yolk-sac larvae drifting from the river appear to be mixed with larger post yolk-sac larvae of estuarine origin resulting in temporary retention at the mouth of Ouelle River. However, longer ebb phases in the river result in a net transport of smelt larvae towards the St. Lawrence estuary. We conclude that the riverine transport and mixing of yolk-sac larvae with the estuarine water mass is controlled principally by the hydrodynamics of the system and the nighttime hatching and specific gravity of yolk-sac larvae.
Historical Relationships between Phosphorus Loading and Biogenic Silica Accumulation in Bay of Quinte Sediments
Authors: Schelske Claire L. , Conley Daniel J. , Warwick William F.
Published: November 2008

Sediments from Warwick's 1972 Glenora-B core from the Bay of Quinte, Lake Ontario, were analyzed to compare the historical relationship between the accumulation of biogenic silica (BSi) and total phosphorus (TP). The similarities in patterns provide evidence that increased phosphorus (P) inputs caused increased diatom production and BSi accumulation. BSi accumulation increased soon after initial European settlement by French Sulpicians in 1669 and reached maximum levels during the early 1850s when forest clearance and erosion of the deforested drainage basin increased sediment accumulation rates 110-fold compared with rates before 1669. Maximum rates of BSi and TP accumulation increased 170-fold and 150-fold, respectively, during the same period. Ratios of BSi:TP were about sixfold greater in the sediments deposited after 1888 than in those deposited prior to 1669, indicating that the proportion of available P in TP inputs increased with increased disposal of domestic sewage into the bay as populations shifted to urban centers. Increases in BSi accumulation above the Ambrosia horizon (dated at 1852) indicate that sediments can be a significant sink for BSi. Although the onset of Si depletion cannot be confirmed with data from this core, there is clear evidence that BSi accumulation increased as the result of increased P inputs.
Effects of Density and Microdetritus Enrichment on the Growth of Chironomid Larvae in a Small Pond
Authors: Rasmussen Joseph B.
Published: November 2008

Densities, species-ratios, and food regimes of chironomid larvae were manipulated in enclosures placed in a small prairie pond, and effects of these treatments on the growth rates of larvae of Chironomus riparius and Glyptotendipes paripes were measured. These two species have tubiculous microphagous larvae that make up the majority of the benthos of the study pond. Intraspecific density effects strongly reduced growth rates for both species; however, interspecific effects were weak and sometimes not statistically significant. Chironomus riparius responded to the addition of sedimented microdetritus with a substantial increase in its growth rate, whereas G. paripes showed no response. The results indicate that the larvae of the two species can coexist stably at densities high enough to result in substantial intraspecies competition, and that differences associated with their mode of feeding contribute to resource partitioning. A sharp reduction in chironomid larval densities resulting from poor weather during the emergence period showed that the abiotic environment can override density effects in determining year-to-year abundance of these larvae.
Bioaccumulation and Bioconversion of Dietary Labeled Fatty Acids in Artemia and Winter Flounder (Pseudopleuronectes americanus)
Authors: Schauer Paul S. , Simpson Kenneth L.
Published: November 2008

One-day-old Artemia were fed for 14 d on nine different rice bran diets, most containing either [1-14C]18:2 ω6 or [1-14C]18:3 ω3, along with various nonlabeled fatty acids. The 15-d-old Artemia were then fed as labeled diets to winter flounder (Pseudopleuronectes americanus). Although 18:2 ω6, 18:3 ω3, and 20:5 ω3 were primarily bioaccumulated, all 15-d-old Artemia groups contained some22:6 ω3, even when it was not present in the diet. Therefore, the 15-d-old Artemia had bioconverted small amounts of 18:2 ω6 and 18:3 ω3 to 20:5 ω3 and 22:6 ω3. The bioconversion rate was substantially reduced when either 20:5 ω3 or 22:6 ω3 was present in the diet. When fed the 15-d-old Artemia, the winter flounder accumulated 20:5 ω3 and 22:6 ω3 and also bioconverted some of the 18:3 ω3 to 20:5 ω3 and 22:6 ω3. Those fish fed diets that contained lower levels of 20:5 ω3 and 22:6 ω3 contained higher levels of radioactively labeled 20:5 ω3 and 22:6 ω3. When 20:5 ω3 and 22:6 ω3 were present from the diet, the radioactivity generally accumulated in the 20:4 ω3 and 20:5 ω3 fatty acids.
Statistical Evaluation of a Large-Scale Fishing Experiment Designed to Test for a Genetic Effect of Size-Selective Fishing on British Columbia Pink Salmon (Oncorhynchus gorbuscha)
Authors: McAllister Murdoch K. , Peterman Randall M. , Gillis Darren M.
Published: November 2008

Since 1950, stocks of British Columbia pink salmon (Oncorhynchus gorbuscha) have shown up to a 34% decrease in mean adult body weight, causing significant reduction in economic value of commercial harvests. Previous research suggests that this trend is due to size-selective harvesting of large fish, but changes in oceanographic conditions are a plausible alternative. Corrective action by management agencies requires that the true causal mechanism be identified. We therefore examined several possible designs for a large-scale fishing experiment devised to test the size-selective fishing hypothesis. These designs would generate accurate and precise field estimates of the heritability (h2) of growth rate, which is important because it, in combination with the selection differential (D) caused by fishing, determines how rapidly body size changes. Monte Carlo simulations showed that block designs with three to six spatial replicates and relatively short durations generated high statistical power. For example, for h2 = 0.22, D = 0.25 kg, and four spatial replicates, an 8-yr experiment resulted in power = 0.87, which gave a SE < 0.10 for h2 = 0.22. We conclude that some experimental designs have good potential to test the possible effects of size-selective fishing on mean adult size of British Columbia pink salmon.
La périodicité de la croissance chez la femelle de l'esturgeon jaune (Acipenser fulvescens) du fleuve Saint-Laurent est-elle reliée à la périodicité de la reproduction?
Authors: Guénette Sylvie , Goyette Daniel , Fortin Réjean , Leclerc Jean , Fournier Nelson , Roy Gilles , Dumont Pierre
Published: November 2008

Measurements of annual increments on cross-sections of the first ray of the pectoral fin of 125 St. Lawrence River female lake sturgeon (Acipenser fulvescens) aged 24 yr and older were used to test the correspondance between growth patterns at the margin of the sections and the state of maturity of the fish. For each of the 21 females aged 34 yr and older, and for the upper Ottawa River specimens presented by Roussow (1957. J. Fish. Res. Board Can. 14: 553–572), annual increments were treated as a temporal series and analysed with the contingency periodogram. The mean age at first spawning was determined using the age at the end of the first belt of crowded annuli, following Roussow. Only 3 of the 21 females aged 34 yr and older showed a typical succession of belts of large and narrow annuli. The most frequent periods were 5–11 yr, using the periodogram, as compared with 6–9 yr for Roussow' specimens. No significant correspondance was found between the pattern of the last five annual increments and the state of maturity. The mean age at first spawning, estimated at 19 yr by this technique, is lower than the mean age of sexual maturity determined for St. Lawrence River females based on the examination of the gonads (26 yr).
Effects of Sounds from a Geophysical Survey Device on Catch-per-Unit-Effort in a Hook-and-Line Fishery for Rockfish (Sebastes spp.)
Authors: Skalski John R. , Pearson Walter H. , Malme Charles I.
Published: November 2008

We examined the concern of commercial fishermen that the sounds generated by acoustic geophysical survey devices result in decreased commercial catches. In blind experimental trials, a test of effects was performed on the rockfish (Sebastes spp.) hook-and-line fishery located along the central California coast. A single 1639-cm3 air gun with a source level of 223 dB re 1 μPa was used to produce peak pressures above 186 dB re 1 μPa at the base of rockfish aggregations. There was an average decline in catch-per-unit-effort of −52.4% (90% confidence interval −27.9%, −76.9%) under emission conditions relative to control trials. This overall decline was also reflected in the individual catches of chilipepper (S. goodei (α = 0.046)), bocaccio (S. paucispinis (α = 0.007)), and greenspotted rockfish (S. chlorostictus (α = 0.021)). The overall reduction in catch translated to an average economic loss of 49.8% (90% confidence interval −21.7%, −77.9%) under the test conditions of this experiment. Fathometer recordings during the study showed no significant change in an index of aggregation size as the result of air-gun emissions (α = 0.374). However, aggregation height appeared to change as the result of emission (α = 0.094) after adjustment for species composition of the catch.
Influence of Hydrographic Conditions and Wind Forcing on the Distribution and Abundance of Dungeness crab, Cancer magister, Larvae
Authors: Hobbs Roderick C. , Botsford Louis W. , Thomas Andrew
Published: November 2008

The distribution of larval Dungeness crab (Cancer magister) was sampled by joint U.S.A./U.S.S.R. ichthyoplankton surveys off the coasts of Washington, Oregon, and northern California involving more than 120 stations from 5 to 360 km offshore and between 40 and 48°N latitude in each of the five years 1981–85. Observed cross-shelf distributions of megalopae were consistent with a mechanism by which diel vertical migratory behavior of the late-stage megalopae in the presence of wind-induced currents results in onshore transport to favorable settlement areas. Total onshore transport for 45 d prior to sampling, estimated as the effects of wind on a passive particle at the surface at night and in the Ekman layer during the day, was correlated with the nearshore megalopal abundance. Mean larval densities for each of the five cruises declined exponentially with time of year of the cruise. This implied (1) an instantaneous mortality rate of 0.066∙d−1 and (2) that survival is independent of inter-annual variation in environment. Abundance of megalopae was not correlated with station hydrographic data (salinity, temperature, and dissolved oxygen) nor chlorophyll levels (satellite data from the Coastal Zone Color Scanner).
Sublethal Responses of Coho Salmon (Oncorhynchus kisutch) to Suspended Sediments
Authors: Servizi James A. , Martens Dennis W.
Published: November 2008

Underyearling coho salmon (Oncorhynchus kisutch) were exposed to sublethal concentrations of Fraser River suspended sediments (SS) in the laboratory. Comparisons with other rivers indicated that Fraser River sediments caused the lowest turbidity for a given SS value. Blood sugar levels (y) were elevated and directly proportional to SS exposure (x) according to y = 5.79 + 4.23(x). Published blood sugar data for adult sockeye salmon (O. nerka) exposed to Fraser River SS were in agreement with the linear relationship for underyearling coho. Cough frequency was elevated approximately eightfold over control levels at 0.24 g SS∙L−1. No increase in cough frequency was observed at 0.02 g SS∙L−1. Avoidance was defined by movement to the surface to escape higher SS at depth. Mean avoidance (y) was related to SS by y = 0.077 + 4.457(x) − 1.547(x2) + 0.202(x3). Mean avoidance was less than 5% up to the inflection point at 2.55 g SS∙L−1 but rose to approximately 25% at 7.0 g SS∙L−1. Laboratory results indicated that sublethal responses could be expected at naturally occurring SS levels in the Fraser River.
A Fur Seal Simulation Model to Explore Alternative Management Strategies
Authors: Wickens P. A. , Shelton P. A. , David J. H. M. , Field J. G. , Oosthuizen W. H. , Roux J-P. , Starfield A. M.
Published: November 2008

A simulation model is formulated for the South African fur seal (Arctocephalus pusillus pusillus) to evaluate the appropriate management action when culling to reduce population growth rate, culling to decrease fish consumption by seals, or harvesting to maximise numbers of seals removed. There is disturbance associated with bull sealing which increases pup mortality and reduces pregnancy rates, but this is not well quantified. Disturbance can be included or excluded from model runs. To reduce population growth, cow removal is most effective, but the population sex ratio becomes severely altered and this may be undesirable ecologically. Reduction of fish consumption is best achieved either by removing cows, with the same caveat regarding sex ratio, or by removing bulls and including disturbance effects. However, the acceptability of a reduction achieved by humans disrupting seals is questionable, and the continued removal of bulls may eventually lead to further decreases in pregnancy rate. To maximise a harvest, the relative commercial value of different seal products is considered, and bull removal, excluding disturbance effects, followed by removal of pups achieves this aim most effectively.
A Bioenergetics Model of Zebra Mussel, Dreissena polymorpha, Growth in the Great Lakes
Authors: Schneider Daniel W.
Published: November 2008

An individual growth model of the zebra mussel, Dreissena polymorpha, is presented, based on weight- and temperature-specific physiological parameters taken from the literature on zebra mussels and marine mussels. Given food availability and water temperature the model can predict growth and consumption of zebra mussels in diverse environments. The model was tested with data from Lake Constance and matches observed growth fairly closely. Using the functional response of zebra mussels to increasing food concentration, the model simulates individual zebra mussel growth in novel habitats. For the Great Lakes, the following predictions were made: zebra mussels have bimodal growth patterns, with rapid growth in the spring and fall during periods of high food availability and moderate temperatures; growth rates are highest in Lake Ontario and lowest in Lake Superior, reflecting the trophic gradient in the Great Lakes; based on published weight/fecundity relationships, zebra mussels reach reproductive size in all of the Great Lakes except the main body of Lake Superior; and local eutrophication (e.g. Duluth/Superior Harbor) increases zebra mussel growth rates. Modelled consumption rates in Lakes Erie and Ontario are also consistent with rates of consumption by the zebra mussel in eutrophic and mesotrophic European lakes.
Spatial Heterogeneity of Littoral Fish Assemblages in Lakes: Relation to Species Diversity and Habitat Structure
Authors: Benson Barbara J. , Magnuson John J.
Published: November 2008

We quantified the spatial heterogeneity in nearshore fish community composition within six Wisconsin lakes and examined its relation to habitat heterogeneity and species diversity. Fish abundance was estimated annually (1981–84) using seines at six sites in each lake. Substrate type, macrophyte growth form, and depth gradient were noted at each site. Species richness was estimated as the expected number of species when the number of individuals was held constant over lakes (rarefaction). Fish community spatial heterogeneity (the average percent dissimilarity in fish species composition over all possible pairs of seine sites within a lake) differed among lakes; it was positively correlated with within-lake variation in the depth gradient and with species diversity as estimated by rarefaction. We tested whether differences in community spatial heterogeneity among lakes resulted simply from differences in species diversity using a randomization test based on random permutations of the rows (seine hauls) in the species composition data matrix. Lakes differed in the extent to which the observed community heterogeneity exceeded the randomization results. Spatial heterogeneity of the fish community, as opposed to sampling phenomena resulting from differences in richness, was a strong factor in some lakes.
Genetic Identification and Implications of Another Invasive Species of Dreissenid Mussel in the Great Lakes
Authors: May Bernie , Marsden J. Ellen
Published: November 2008

In this paper we report the discovery and implications of a second nonindigenous species of dreissenid mussel in the Great Lakes. This species was detected in a routine screening of zebra mussels (Dreissena polymorpha) for allozyme variability. The two species differ at allozyme loci (Nei's I = 0.30 using 12 loci) and in their shell morphology (the second species lacks the acute angle, or carina, between the ventral and dorsal surfaces of the shell of the zebra mussel). As a working name, at least until its species identity is discovered, we have called the new species the "quagga mussel." Currently, this mussel occurs in Lake Ontario in equal frequencies with D. polymorpha. Its low frequency of occurence in neighboring waters (e.g. the Erie canal, Niagara River, and outlet to Onondaga Lake) and lack of occurrence in any of the other Great Lakes suggest that (1) its point of introduction to North America was in Lake Ontario and (2) its range may expand.
Tests of Genetic Stock Identification Using Coded Wire Tagged Fish
Authors: Brodziak Jon , Bentley Boyd , Bartley Devin , Gall Graham A. E. , Gomulkiewicz Richard , Mangel Marc
Published: November 2008

Genetic Stock Identification (GSI) uses allozyme variation to determine the composition of mixed-stock fisheries. The GSI method was tested using real fishery data. We report, for the first time in the primary literature, results of tests of GSI in which source stock and ocean-caught mixture samples were separately obtained and the mixture composition was known exactly because the fish used were marked by Coded Wire Tags (CWTs). The accuracy of GSI and its dependence on the quality of genetic data were studied by computer experiments. Rare alleles, which could result from poor sampling procedures, can lead to significant estimation errors. Estimation accuracy depended on the concordance between stocks present in the baseline data and the mixture sample and on the number of loci used in the analysis. Two methods for computing the contributions of groups of source stocks were found to be comparable under most, but not all, conditions. In a blind test of GSI, stock group composition estimates had absolute errors of less than 3%. This suggests that the GSI method can produce accurate stock contribution estimates using real fishery data.