bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemato‐biochemical changes, disease incidence and live weight gain in individual versus group reared calves fed on different levels of milk and skim milk
Authors: BABU Lakshman K. , PANDEY Harnarain , PATRA Ramesh C. , SAHOO Artabandhu
Published: January 2009

A 2 × 3 factorial design was used to study the impact of rearing systems, individual (I) versus group (G) and different levels of milk/skim milk feeding (F1, F2 and F3) on hemato‐biochemical profile, disease incidence and average daily gain of crossbred (Bos indicus × Bos taurus) calves. Six calves were taken in each group on the basis of their birth weight and housed in individual (2.20 × 1.16 m2/calf) or in group pens (2.20 × 1.03 m2/calf). After 3 days of colostrum feeding, calves were allocated to one of three different milk feeding schedules: milk fed up to 8 weeks of age (F1), milk up to 4 weeks followed by 50% replacement by skim milk up to 6 weeks and 100% thereafter (F2) and 100% replacement of milk with skim milk after 4 weeks (F3). Calf starter and cereal green fodders were fed ad libitum from the second week of age and continued for 14 weeks. Parameters on health and disease profiles of calves (disease incidence, duration of illness, response to treatment and recovery) and weekly live weight change were recorded. Calf scour predominated (52.8%), followed by joint ill (25.0%) and respiratory infections (19.4%). The disease incidence was greater (P < 0.01) in individually housed calves (94.4 vs. 55.9%). The management of navel ill required longer recovery (7.01 days) followed by joint ill (4.87 days) and respiratory infection (4.86 days). The average daily gain during 0–14 weeks of age was higher (P < 0.01) in group‐housed calves (433 ± 22 vs. 355 ± 31 g), while the effect of feeding was not significant. Blood samples collected at 4, 8 and 14 weeks of age showed some periodic higher concentrations (but within normal range) of plasma urea and total protein in group housed calves on F2 and F3 feeding schedules in response to high protein intake. Other parameters remained non‐significantly different. Thus, group‐housed calves can be reared successfully with comparatively better performance and less illness than individually housed ones under the present health care and housing management system. However, the system should not be used as a substitute for good management, and frequent observations of calves should be an integral part of any successful rearing program.
A simple and efficient method for extraction of PCR‐amplifiable DNA from chicken eggshells
Authors: RIKIMARU Kazuhiro , TAKAHASHI Hideaki
Published: January 2009

Recently, we reported a method for discriminating a Japanese brand of chicken, the Hinai‐jidori. As an application of this method for discriminating Hinai‐jidori eggs, we here report an efficient method for extracting maternal DNA from eggshells. Eggshell powder was completely decalcified with EDTA solution, and then DNA was isolated by conventional phenol‐chloroform extraction and ethanol precipitation. The efficiency of DNA recovery from eggshells was 50‐fold higher than that of a previously reported method. The recovered DNA could be used for PCR, and 10 markers for identifying the Hinai‐jidori chicken were detected. The genotypes of the Hinai‐jidori exactly matched those of the Hinai‐dori breed. Using this method, Hinai‐jidori and Hinai‐dori eggs could be distinguished from the eggs of Rhode Island Reds. This is the first report of a technique that can be used to discriminate the eggs of Hinai‐jidori from those of other chickens, and it can also be utilized to validate the labeling of Hinai‐jidori eggs in the market.
The Administrative Presidency and Bureaucratic Control: Implementing a Research Agenda
Authors: RUDALEVIGE ANDREW
Published: January 2009

As Richard Nathan pointed out inThe Administrative Presidency25 years ago, much contemporary policy making occurs through the execution of the laws and the management process. Thus, the conditions under which administrative power can be effectively exercised are important components of future research. In short, we must revisit an old question: Who controls the bureaucracy? This article sets out a research agenda for doing so by examining a set of related strategies that presidents have utilized in their efforts to assert control over the bureaucracy—namely, centralization, politicization, and reorganization—in the course of linking two strands of literature with significant overlap but little conversation between them: the largely quantitative bureaucratic control literature, and the largely qualitative “politicized presidency” literature focused on presidential structures. Each strand, I suggest, can inform and enrich the other; both would benefit from better measures of inputs, outputs, and, crucially, the processes that connect the two and influence the success of policy implementation.
The Appointments Process and the Administrative Presidency
Authors: ABERBACH JOEL D. , ROCKMAN BERT A.
Published: January 2009

This essay reviews and analyzes the literature on presidential appointments in light of the growing tendency of chief executives to use the methods associated with what is now known as the administrative presidency. It closes with a discussion of the normative issues raised by the existing appointment system, one that appears to generate incompetence, distrust, and delays in filling posts.
The Law: The Baker‐Christopher War Powers Commission
Authors: FISHER LOUIS
Published: January 2009

In July 2008, the National War Powers Commission released a detailed report that recommended the repeal of the War Powers Resolution of 1973 and its replacement with the War Powers Consultation Act. Co‐chaired by former secretaries of state James A. Baker III and Warren Christopher, the commission report promised “equal respect” to the legislative and executive branches, but, in fact, it strengthened the president's capacity to initiate war and greatly weakened congressional and public control. Instead of addressing the framers' fear of placing the war power in the hands of a single executive with an appetite for military glory and fame, the report claimed that the U.S. Constitution is “ambiguous” about war powers and that federal courts “for the most part” have declined jurisdiction over war power cases. Both assertions are false.
Polls and Elections: How Did the Primary Vote Forecasts Fare in 2008?
Authors: STEGER WAYNE P.
Published: January 2009

This study compares the leading primary vote forecasts for a common set of candidates and nomination campaigns, updated through 2008. Pre‐primary and post–New Hampshire primary forecasts are estimated. Models that predicted well the primary vote from 1980 to 2000 produce substantial errors in prediction for the 2004 and 2008 presidential nominations. This suggests that the factors driving presidential nominations during the 1980s and 1990s are changing in ways that have increased the potency of campaign momentum in presidential nominations. Post–New Hampshire forecasts, which capture the effects of momentum from the early contests, continue to predict well candidates' primary vote shares.
Mitochondria regulate platelet metamorphosis induced by opsonized zymosan A – activation and long‐term commitment to cell death
Authors: Matarrese Paola , Straface Elisabetta , Palumbo Giuseppe , Anselmi Maurizio , Gambardella Lucrezia , Ascione Barbara , Del Principe Domenico , Malorni Walter
Published: January 2009

Changes in the mitochondrial membrane potential play a key role in determining cell fate. Mitochondria membrane hyperpolarization has been found to occur after cell activation, e.g. in lymphocytes, whereas depolarization is associated with apoptosis. The aim of this study was to investigate the effects of an immunological stimulus, i.e. opsonized zymosan A, on human platelet mitochondria by means of flow and static cytometry analyses as well as biochemical methods. We found that opsonized zymosan induced significant changes of platelet morphology at early time points (90 min). This was associated with increased production of reactive oxygen species, and, intriguingly, mitochondrial membrane hyperpolarization. At a later time point (24 h), opsonized zymosan was found to induce increased expression of CD47 adhesion molecule, platelet aggregation, mitochondrial membrane depolarization and phosphatidylserine externalization. Although these late events usually represent signs of apoptosis in nucleated cells, in opsonized zymosan‐treated platelets they were not associated with membrane integrity loss, changes in Bcl‐2 family protein expression or caspase activation. In addition, pre‐treatment with low doses of the ‘mitochondriotropic’ protonophore carbonyl cyanide p‐(trifluoro‐methoxy)phenylhydrazone counteracted mitochondrial membrane potential alterations, production of reactive oxygen species and phosphatidylserine externalization induced by opsonized zymosan. Our data suggest that mitochondrial hyperpolarization represents a key event in platelet activation and remodeling under opsonized zymosan immunological stimulation, and opsonized zymosan immunological stimulation may represent a useful tool for understanding of the pathogenetic role of platelet alterations associated with vascular complications occurring in metabolic and autoimmune diseases.
Spontaneous cervicothoracolumbar pneumorrhachis, pneumomediastinum and pneumoperitoneum
Authors: Al‐Mufarrej Faisal , Gharagozloo Farid , Tempesta Barbara , Margolis Marc
Published: January 2009

Introduction:  Pneumorrhachis, or epidural pneumatosis, is a rare entity that is usually traumatic or iatrogenic. Usually, the epidural emphysema is limited to a few vertebral spaces. Less commonly, it is secondary to mediastinal air that tracks into the epidural space. Mediastinal air is usually associated with subcutaneous emphysema, but rarely is it associated with pneumopericardium or pneumoperitoneum. The cause of pneumomediastinum is usually identifiable on history or radiology.

Methods:  Report of a case.

Results:  We report the extremely rare simultaneous occurrence of self‐limiting cervicothoracolumbar pneumorrhachis, pneumomediastinum, cervical subcutaneous emphysema and pneumoperitoneum in a healthy 20‐year‐old gentleman in the absence of an identifiable cause.

Conclusion:  Extensive pneumorrhachis and pneumoperitoneum may simultaneously accompany pneumomediastinum and subcutaneous emphysema in the absence of an identifiable cause and still follow a benign clinical course.

Please cite this paper as: Al‐Mufarrej F, Gharagozloo F, Tempesta B and Margolis M. Spontaneous cervicothoracolumbar pneumorrhachis, pneumomediastinum and pneumoperitoneum. The Clinical Respiratory Journal 2009; 3: 239–243.
A Comparison of the Impact of Information from a Clinician and Research‐based Information on Patient Treatment Choice in Dentistry
Authors: Gilmore Diane , Sturmey Peter , Newton J. Timothy
Published: January 2009

Objectives:There is an imperative that clinicians should employ an evidence‐based approach to both clinical care and treatment, and involve patients in the decision‐making process. In Britain, public policy emphasizes the importance of patient involvement, participation and partnership in health care, however little is known of the effect of evidence‐based information on this. This study compares treatment decisions made by dental patients on the basis of two sources of evidence: clinician and research. Method:Vignette method with the two sources of evidence as experimental variables. The study population was a convenience sample of dental patients recruited from a clinic waiting area at a Dental Hospital (n=lOO). Each participant read a vignette describing a visit to the dentist for treatment of severe toothache in a back tooth. The nature and purpose of the visit was identical in each vignette. The participants indicated their decision about possible treatment, based on the information they had been given in the vignette and rated their confidence in the decision on a three point Likert scale. Additionally participants were asked to rate their own oral health. Results:Research evidence influences the confidence patients have in their in decision especially when it supports clinical judgement and where individuals value their oral health. Research evidence does not replace the confidence that patients have in the dentist's clinical judgement. Conclusion: Dental patients' willingness to engage in treatment is in fluenced by the dentist's clinical recommendation and the importance of oral health to the patient.
Deficits in Perceptions of Oral Health Relative to General Health in Populations
Authors: Sanders Anne E. , Slade Gary D.
Published: January 2009

Objectives:To compare perceptions of general health versus oral health within two populations. Methods:Secondary analysis of cross‐sectional survey data obtained from representative samples of dentate adults in Australia and the United States. Australian data were collected in the 2002 National Dental Telephone Interview Survey and United States data were from the NHANES, 1988–1994. A stratified analysis compared self‐ratings of general and oral health among groups classified by age, socioeconomic status and access to dental care. Results:In Australia, 43.6% rated their dental health ‘very good’ or ‘excellent’ whereas 58.6% rated their general health ‘very good’ or ‘excellent’ ‐ a deficit of 15.0%. In the US, there was a comparable deficit of 24.2%. The deficit could be explained as a ‘generation gap’ where oral health ratings of the youngest cohort resembled the general health ratings of middle‐aged adults in Australia and retirees in the US. An ‘affluence gap’ was evident where the oral health ratings of wealthier adults resembled the general health ratings of disadvantaged adults. Among Australians with private dental insurance who had visited a dentist in the past year the oral health deficit was negligible. Similar stratification in the US sample considerably attenuated the deficit. Conclusion:There is a deficit in perceived oral health compared with general health at all stages of adulthood and spanning the socioeconomic spectrum. The deficit was diminished among insured adults who had made a dental visit within the preceding year, suggesting that improved access to dental services may help redress the discrepancy.
Linguistic Adaptation and Validation of the General Oral Health Assessment Index (GOHAI) in an Elderly Japanese Population
Authors: Naito Mariko , Suzukamo Yoshimi , Nakayama Takeo , Hamajima Nobuyuki , Fukuhara Shunichi
Published: January 2009

Objectives:This study sought to develop a Japanese version of the General Oral Health Assessment Index (GOHAI) and validate its use in an elderly Japanese population. Methods:The GOHAI scale was translated in a standardized way consisting of forward translation, pilot study, and backward translation. Psychometric properties of the final version were assessed on 175 participants (mean age: 70.0 years, SD 6.4). Results:The response rate was more than 98% for each item. The reliability in terms of a Cronbach's alpha value was 0.89. The mean GOHAI scores were significantly lower for participants with poor perceived oral health (P<0.001) or poor perceived general health (P<0.01). Significant correlations were observed between the GOHAI scores and the general health or physical functioning scores of the Medical Outcome Study Short Form 36 (P<0.01). Conclusions:The present study showed that the Japanese version of the GOHAI was psychometrically valid in an elderly sample population.
Association of Smoking in Household and Dental Caries in Japan
Authors: Tanaka Keiko , Hanioka Takashi , Miyake Yoshihiro , Ojima Miki , Aoyama Hitoshi
Published: January 2009

Objectives:The study investigated the relationship between smoking in the household and dental caries in Japanese children using nationally representative cross‐sectional data. Methods:This study included 925 children aged 1–14 years. A child was considered to have decayed and/or filled teeth if a dentist diagnosed these conditions in deciduous or permanent teeth. Smoking in the household was defined as positive if someone in the household reported smoking cigarettes. Results:No statistically significant relationship was observed between household smoking and canes experience. However, smoking in the household was independently associated with an increased prevalence of decayed teeth. The adjusted mean of filled teeth among children exposed to household smoking was higher than that among non‐exposed children. Conclusions:The results of the study failed to substantiate a positive association between passive smoking and caries experience in Japanese children.
Design and Evaluation of a New General-Purpose Device for Calibrating Instrumented Spatial Linkages
Authors: Nordquist Joshua A. , Hull M. L.
Published: January 2009

Because instrumented spatial linkages (ISLs) have been commonly used in measuring joint rotations and must be calibrated before using the device in confidence, a calibration device design and associated method for quantifying calibration device error would be useful. The objectives of the work reported by this paper were to (1) design an ISL calibration device and demonstrate the design for a specific application, (2) describe a new method for calibrating the device that minimizes measurement error, and (3) quantify measurement error of the device using the new method. Relative translations and orientations of the device were calculated via a series of transformation matrices containing inherent fixed and variable parameters. These translations and orientations were verified with a coordinate measurement machine, which served as a gold standard. Inherent fixed parameters of the device were optimized to minimize measurement error. After parameter optimization, accuracy was determined. The root mean squared error (RMSE) was 0.175 deg for orientation and 0.587 mm for position. All RMSE values were less than 0.8% of their respective full-scale ranges. These errors are comparable to published measurement errors of ISLs for positions and lower by at least a factor of 2 for orientations. These errors are in spite of the many steps taken in design and manufacturing to achieve high accuracy. Because it is challenging to achieve the accuracy required for a custom calibration device to serve as a viable gold standard, it is important to verify that a calibration device provides sufficient precision to calibrate an ISL.
Two-Dimensional Simulation of Flow and Platelet Dynamics in the Hinge Region of a Mechanical Heart Valve
Authors: Govindarajan V. , Udaykumar H. S. , Chandran K. B.
Published: January 2009

The hinge region of a mechanical bileaflet valve is implicated in blood damage and initiation of thrombus formation. Detailed fluid dynamic analysis in the complex geometry of the hinge region during the closing phase of the bileaflet valve is the focus of this study to understand the effect of fluid-induced stresses on the activation of platelets. A fixed-grid Cartesian mesh flow solver is used to simulate the blood flow through a two-dimensional geometry of the hinge region of a bileaflet mechanical valve. Use of local mesh refinement algorithm provides mesh adaptation based on the gradients of flow in the constricted geometry of the hinge. Leaflet motion is specified from the fluid-structure interaction analysis of the leaflet dynamics during the closing phase from a previous study, which focused on the fluid mechanics at the gap between the leaflet edges and the valve housing. A Lagrangian particle tracking method is used to model and track the platelets and to compute the magnitude of the shear stress on the platelets as they pass through the hinge region. Results show that there is a boundary layer separation in the gaps between the leaflet ear and the constricted hinge geometry. Separated shear layers roll up into vortical structures that lead to high residence times combined with exposure to high-shear stresses for particles in the hinge region. Particles are preferentially entrained into this recirculation zone, presenting the possibility of platelet activation, aggregation, and initiation of thrombi.
A Model of the Upper Extremity Using FES for Stroke Rehabilitation
Authors: Freeman Chris T. , Hughes Ann-Marie , Burridge Jane H. , Chappell Paul H. , Lewin Paul L. , Rogers Eric
Published: January 2009

A model of the upper extremity is developed in which the forearm is constrained to lie in a horizontal plane and electrical stimulation is applied to the triceps muscle. Identification procedures are described to estimate the unknown parameters using tests that can be performed in a short period of time. Examples of identified parameters obtained experimentally are presented for both stroke patients and unimpaired subjects. A discussion concerning the identification’s repeatability, together with results confirming the accuracy of the overall representation, is given. The model has been used during clinical trials in which electrical stimulation is applied to the triceps muscle of a number of stroke patients for the purpose of improving both their performance at reaching tasks and their level of voluntary control over their impaired arm. Its purpose in this context is threefold: Firstly, changes occurring in the levels of stiffness and spasticity in each subject’s arm can be monitored by comparing frictional components of models identified at different times during treatment. Secondly, the model is used to calculate the moments applied during tracking tasks that are due to a patient’s voluntary effort, and it therefore constitutes a useful tool with which to analyze their performance. Thirdly, the model is used to derive the advanced controllers that govern the level of stimulation applied to subjects over the course of the treatment. Details are provided to show how the model is applied in each case, and sample results are shown.
Open Sea Releases of Atlantic Salmon Smolts, Salmo salar, In Central Norway, 1973–83
Authors: Gunnerød T. B. , Hvidsten N. A. , Heggberget T. G.
Published: January 2009

Low returns of adult Atlantic salmon (Salmo salar) from releases of hatchery-reared smolts initiated experiments to increase recapture rates in the River Surna. A hypothesis that heavy postsmolt mortality due to predation could be reduced by guiding the smolts through coastal areas was tested. Three sites of release were selected: in the Surna, in the fjord, and on the coast off the Surna. Offshore releases gave 111% higher total recapture rates compared with river releases. The remote migration system did not seem to be disturbed by open sea releases, but the number of strayers to rivers other than the Surna increased significantly with the distance between point of release and the native river. Site of release of smolts was more important than genetic background of the fish for the site of recaptures of adult salmon.
Preseason Forecasts of Sockeye Salmon (Oncorhynchus nerka): Comparison of Methods and Economic Considerations
Authors: Bocking Robert C. , Peterman Randall M.
Published: January 2009

We compared the ability of two methods to forecast observed abundances of sockeye salmon (Oncorhynchus nerka) in Bristol Bay, Alaska, stocks from 1956 through 1980. We determined that the commonly used linear forecasting method, based on untransformed abundances of sibling age classes, overestimated sockeye abundances more frequently than did a nonlinear method. Furthermore, the nonlinear method produced mean forecasts that were closer to actual abundances of returns than forecasts from the linear method. We therefore recommend use of the nonlinear method. We also quantified significant economic implications of incorrect preseason forecasts for Bristol Bay sockeye. Deviations of actual escapements from the target are correlated with errors in the preseason forecast. Thus, large errors in preseason forecasts can influence potential long-term harvests and resulting economic benefits. In addition, annual changes in prices of set and drift gill net permits for fishermen were correlated with forecasted annual change in the abundance of sockeye recruits. This result is consistent with the hypothesis that preseason forecasts of sockeye salmon returns affect expectations by fishermen of economic rents (related to profits). Overestimates of abundance of recruits by current methods may thus subsequently lead to overinvestment by fishermen seeking to increase their share of expected rents.
Oxygen Isotope Studies on Sea Scallops, Placopecten magellanicus, from Browns Bank, Nova Scotia
Authors: Tan F. C. , Cai D. , Roddick D. L.
Published: January 2009

Oxygen isotope records from two sea scallops, Placopecten magellanicus, collected alive from Browns Bank, Nova Scotia, show annual cycles that closely approximate the isotopic composition predicted as a function of observed temperatures and the isotopic composition of the ambient seawater. The external growth lines coincided with the most positive δ18O values of the cycles, suggesting their formation during the period of coldest water temperatures (spring). The δ18O results indicate that the growth lines are annual events, consistent with the biological evidence.
Do Rainbow Trout (Salmo gairdneri) Acclimate to Low pH?
Authors: Audet Céline , Wood Chris M.
Published: January 2009

Adult rainbow trout (Salmo gairdneri) previously exposed to long-term sublethal acid stress (3 mo, pH 4.8) in artificial soft water (Ca2+ = 50, Na+ = 50, Cl− = 100 μeq∙L−1) were challenged with acute severe acid exposure (4.5–5 h, pH 4.0). Their response in terms of whole-body ionic exchanges and blood chemistry was compared with that of trout that had no previous history of acid exposure (naive fish). Acute pH 4.0 exposure caused significant ionoregulatory disturbances in both acid-preexposed and naive fish. Rates of net Na+ and Cl− body losses were twice as large in acid-preexposed fish as in naive fish. The two groups showed similar slight net uptake of acidic equivalents. However, the dynamics of acid–base exchange differed, especially with regard to ammonia excretion which was elevated in acid-preexposed fish and inhibited in naive fish. A larger decrease in plasma Na+, red blood cell swelling, and the maintenance of high-stress indicators (elevated plasma glucose and ammonia excretion, depressed osmolality) confirmed that osmo-ionoregulatory disturbances were more intense in acid-preexposed fish than in naive fish. Thus, long-term sublethal acid exposure did not improve but rather significantly decreased the ability of rainbow trout to respond to more severe acid stress. We conclude that acclimation to acid stress does not occur in rainbow trout.
Assessment of Sea Lamprey (Petromyzon marinus) Predation by Recovery of Dead Lake Trout (Salvelinus namaycush) from Lake Ontario, 1982–85
Authors: Bergstedt Roger A. , Schneider Clifford P.
Published: January 2009

During 1982–85, 89 dead fake trout (Salvelinus namaycush) were recovered with bottom trawls in U.S. waters of Lake Ontario: 28 incidentally during four annual fish-stock assessment surveys and 61 during fall surveys for dead fish. During the assessment surveys, no dead lake trout were recovered in April–June, one was recovered in August, and 27 were recovered in October or November, implying that most mortality from causes other than fishing occurred in the fall. The estimated numbers of dead lake trout between the 30- and 100-m depth contours in U.S. waters ranged from 16 000 (0.08 carcass/ha) in 1983 to 94 000 (0.46 carcass/ha) in 1982. Of 76 carcasses fresh enough to enable recognition of sea lamprey (Petromyzon marinus) wounds, 75 bore fresh wounds. Assuming that sea lamprey wounding rates on dead fish were the same as on live ones of the same length range (430–740 mm), the probability of 75 of the 76 dead lake trout bearing sea lamprey wounds was 3.5 × 10−63 if death was independent of sea lamprey attack, thus strongly implicating sea lampreys as the primary cause of death of fish in the sample. The recovery of only one unwounded dead lake trout also suggested that natural mortality from causes other than sea lamprey attacks is negligible.
Copper Intoxication in Chinook Salmon (Oncorhynchus tshawytscha) Induced by Natural Springwater: Effects on Gill Na+, K+-ATPase, Hematocrit, and Plasma Glucose
Authors: Beckman Brian R. , Zaugg Waldo S.
Published: January 2009

Chinook salmon (Oncorhynchus tshawytscha) parr and smolts were exposed to natural springwater with an elevated copper concentration. Gill Na+, K+-ATPase activity in parr was unaffected by 18 h of exposure, while significant inhibition was found in smolts. Under the same exposure conditions, significant increases in hematocrit and plasma glucose were found in both parr and smolts. The results suggest that only the Na+, K+-ATPase enzyme associated with chloride cells in the gill of smolts is susceptible to inhibition by copper, thus explaining the lack of enzyme inhibition found in parr.
Detection of Environmental Influence on Recruitment Using Abundance Data
Authors: Kope Robert G. , Botsford Louis W.
Published: January 2009

Environmental influences on recruitment are usually detected by correlation analysis using environmental and recruitment data. When recruitment data are unavailable, abundance data are sometimes used instead. An abundance time series can be described as a convolution of the recruitment time series, and consequently, when it is used as a proxy for recruitment, the magnitude of correlations is lower and the probability of both type I and type II errors is greater. Two approaches can restore the correlation between the environmental series and the recruitment series: (1) convolution of the environmental series and (2) deconvolution of the abundance series. Convolution of the environmental series increases the variance of computed correlation coefficients and can further increase the probability of type II errors. Deconvolution of the abundance series can recover the correlation between the environment and recruitment without increasing the variance of sample correlation coefficients or the probability of type II errors, as long as the deconvolution is stable and errors in the data are relatively small. When errors in the data are sufficiently large or the deconvolution is sufficiently unstable, the best results may be obtained by simply using abundance as a recruitment index. We evaluate application of the deconvolution technique to chinook salmon (Oncorhynchus tshawytscha) catch and spawner abundance series using both real and simulated data.
Osmoregulatory Ability of Wild Coho Salmon (Oncorhynchus kisutch) and Dolly Varden Char (Salvelinus malma) Smolts
Authors: Johnson Scott W. , Heifetz Jonathan
Published: January 2009

Osmoregulatory ability of wild coho salmon (Oncorhynchus kisutch) and Dolly Varden char (Salvelinus malma) smolts migrating from a small stream in southeastern Alaska was assessed by plasma Na+ levels after a 24-h seawater challenge. Osmoregulatory ability of coho salmon was unaffected by time of out-migration, water temperature, and fish size. Osmoregulatory ability of Dolly Varden char was apparently affected by time of out-migration or water temperature but not by fish size. Char migrating in the first half of the migration period, when water temperature was usually < 8.0 °C, had lower plasma Na+ levels than did char migrating in the second half when temperatures were [Formula: see text]. A plasma Na+ threshold of 170 mmol∙L−1, used by others to separate smolts from silvery parr, indicated that 70% of the coho salmon and 80% of the Dolly Varden char we sampled were physiologically prepared to enter seawater. The remaining fish may have suffered some level of osmoregulatory stress.
Error in Estimation of Feeding Rates from Changes in Mean Body Mass
Authors: Cochran P. A. , Knutsen K. J.
Published: January 2009

Because of nonlinear relationships between body mass and many parameters in energetics models, rates of food intake calculated from change in mean body mass (a typical application of energetics models) do not necessarily equal true mean rates of food intake calculated from individual changes in body mass. Using both hypothetical data and actual field data for largemouth bass (Micropterus salmoides) marked with individually numbered tags, we show that discrepancies increase with variability in body mass but are negligible (< 3.5%) in all cases examined. Biased estimates of change in mean body mass, such as might result from size-selective mortality or sampling gear, can lead to substantial errors in energetics model estimates of mean food consumption rates. Use of growth data for individually marked fish in conjunction with an energetics model permits calculation of confidence intervals, statistical comparison of food consumption rates, and examination of relationships between foraging success and individual body mass.
Predictability of Change in Shoreline Vegetation in a Hydroelectric Reservoir, Northern Sweden
Authors: Nilsson Christer , Keddy Paul A.
Published: January 2009

We asked whether we could predict the responses of vegetation to specified perturbations acting on a known initial state using 10 yr of vegetation data and precise water level records from the Gardiken Reservoir on the Ume River in Sweden; this has a restricted flora and one obvious controlling factor: water level. Abundance and species richness were strongly correlated for both vascular and nonvascular plants (bryophytes and lichens). Duration of flooding was the most important variable controlling those independent variables chosen for study. The change from year t to t + 1 could be roughly predicted for community attributes such as richness and cover (R2 > 0.33) but not for species composition (R2 < 0.04). The initial (preceding-year) state of the system and the duration of flooding (also in the preceding year) were always the two most important independent variables. The major conclusions were that (1) even in this "simple" system with presumably one major control variable, our best regression equation accounted for only 41% of the variation, (2) community properties were more predictable than species composition, and (3) the similarity of the species pool, the lack of coupling from competitive interactions, and the high degree of immaturity may have reduced predictability of species composition.
Response of Headwater Lakes to Varying Atmospheric Deposition in North-Central Ontario, 1979–85
Authors: Kelso J. R. M. , Jeffries D. S.
Published: January 2009

Between 1976 and 1985, loadings of SO42− to the Algoma district (north-central Ontario) varied from a low of 47 (1980) to a high of 84 meq∙m−2 (1978) and was low in years of low annual precipitation. The mean and median lake concentrations of H+ and SO42− in 54 lakes declined between 1979 and 1982 following the period of lowest annual deposition and declined further between 1982 and 1985. Overall, mean lake pH increased 0.35 unit between 1979 and 1982 and an additional 0.07 unit over the next 3 yr. Lake concentrations in the Turkey Lakes watershed exhibited a similar trend. Two lakes without fish in 1979 and with pH's < 5.5 developed white sucker (Catostomus commersoni) populations by 1986 with ages indicating that survival began after 1980. This apparent invasion from downstream populations probably occurred when lake pH's neared 5.5. Although a direct link has not been established, these lakes appear to be extremely responsive to changes in atmospheric deposition. The "recovery" of water quality clearly extends beyond that locally documented at Sudbury, Ontario, yet it remains to be determined to what degree the responses relate to differences in continental deposition and/or responses within the watershed.
Summer Habitat Utilization and Ecology of Cutthroat Trout Fry (Salmo clarki) in Cascade Mountain Streams
Authors: Moore Kelly M. S. , Gregory Stanley V.
Published: January 2009

Emergent cutthroat trout fry (Salmo clarki) were observed in the margins, backwaters, and side channels, collectively called "lateral habitats," of three study streams with different riparian vegetation. Most fry remained in these lateral habitats until the end of their first summer. The abundance of cutthroat fry was proportional to the area of lateral habitat in each of the study streams. Average size and growth rate of fry were related to the effect of site elevation on stream temperature and the influence of riparian vegetation on the availability of invertebrate food. Lateral habitats are characterized by slow, shallow-water, abundant detritus and benthic invertebrate assemblages of high density. Stream margins and backwaters provide gradients of depth and velocity, cover, and access to food that are appropriate to the habitat requirements of fry. Because fry populations are closely related to the abundance and quality of lateral habitats in small streams, these habitats should be included in the assessment of habitat requirements of cutthroat trout.
Seasonal Variation in Faunal Distribution within the Sediments of a Canadian Shield Stream, with Emphasis on Responses to Spring Floods
Authors: Giberson Donna J. , Hall Ronald J.
Published: January 2009

The vertical distribution of invertebrates within the shallow substrates of a Canadian Shield lake outflow stream was examined to determine the importance of season and spate on distribution pattern. Stream invertebrates were found throughout the year to depths of 25 cm below the sediment surface, only about 5 cm above bedrock. Insect abundance showed a strong seasonal pattern, with highest numbers occurring during early winter (December) in all depth zones. Except for Chironomidae, the majority of the insects found below 5 cm were early instar larvae of those found regularly at the surface, Insect abundance was generally higher at the sediment surface than for all other depth zones combined and consisted mainly of one taxon, Prosimulium (Diptera: Simuiiidae). Non-insect invertebrates were always more abundant in the hyporheos than at the surface. Total invertebrate abundance (primarily Prosimulium) at the sediment surface decreased by about 40% during the spring snowmelt flood, but no significant changes in abundance occurred in the hyporheos during this period. Chemical analysis of surface and interstitial water showed that both pH and alkalinity decreased slightly in surface waters during the flood, but increased within the hyporheos, particularly on the rising limb of the flood hydrograph.
Apparent Digestibility in Rainbow Trout (Salmo Gairdneri): Influence of Hypoxia
Authors: Pouliot T. , Noüe J. de la
Published: January 2009

We assessed the influence of hypoxia, which is likely to reduce the productivity of fish culture, on the digestibility of nutrients in rainbow trout (Salmo gairdneri). Rainbow trout (seven to each diet) were kept for 8 d in water with an oxygen saturation level of 40.0 ± 4.0%, while control fish were kept in 89.4 ± 4.2% oxygen-saturated water. Three isonitrogenous and isocaloric diets composed of different sources of protein (animal, plant, and mixed) were used. The apparent digestibility coefficients (ADC) were calculated by the indirect method (chromic oxide) after the automatic collection of feces. The experimental hypoxia used did not change the ADC for protein (total nitrogen), gross energy, or dry matter. The amino acids only showed a tendency for better absorption: proline, glycine, alanine, and tryptophan had a significantly higher ADC (P < 0.05) in experimental fish than in control fish when the animal protein based diet was used. Finally, we noted that feed intake was diet dependent. In contrast with what we observed with the commercial (mixed protein sources) and plant protein based diets, the fish receiving the animal protein based diet maintained a normal (or returning to normal) feed intake when they were subjected to hypoxia.
The effect of mineral supplements on nutrient concentrations and pool sizes in the alimentary tract of reindeer fed lichens or concentrates during the winter
Authors: Staaland H. , Jacobsen E. , White R. G.
Published: January 2009

Domestic reindeer (Rangifer tarandus tarandus L.), fed a mixed lichen or concentrate diet with or without a mineral supplement, were killed, and 21 segments of the digestive tract were analyzed for weight of digesta and concentrations of water, organic matter (OM), N, Ca, P, Mg, Na, K, Cl, and S. Trends in alimentary nutrient concentrations were of two patterns: (A) Ca, P, Mg, S, OM, and N increased in concentration per unit wet weight in ruminal to omasal contents and, followed by a decline from abomasal to jejunal contents, there was a steady increase to the rectal contents; (B) water, Na, Cl, and, with some modification, K decreased in concentration from the small intestinal to the rectal contents. The concentrate diet was associated with significantly increased body weight, plasma P levels, and N, P, and Mg levels in most sections of the alimentary tract. Mineral supplementation suppressed concentrations of N in the entire alimentary tract of lichen-fed reindeer but was associated with increased concentrations of P, Ca, and Mg in the entire tract of both the concentrate and lichen diets.
The life history of Zapada columbiana (Plecoptera: Nemouridae) in a Rocky Mountain stream
Authors: Mutch R. A. , Pritchard G.
Published: January 2009

The life cycle of Zapada columbiana (Claassen) is basically 3 years in a subalpine stream in the Rocky Mountains of Alberta, although some individuals may complete their life cycle in 2 years. Adults emerged from mid-April to early June and did not disperse far from the stream. Emerging adults and ovipositing females showed no tendency to move upstream. The eggs hatched prior to winter of the same year and growth of larvae was confined to the ice-free period of June to November. It was estimated that at any time during the growth season at least 50% of the population in the stream was in moss covering boulders and cobbles in riffles. Moss was the predominant component in guts of larvae taken from moss, and detritus predominated in guts of larvae from other habitats. During the winter, detritus (from conifer needles) was the major component of the gut contents. Experiments demonstrated that larvae grew faster on moss than on conditioned Salix glauca leaves. Larvae grew on conifer needles only when the latter were highly conditioned and fragmented. This study has indicated that Zapada columbiana, an abundant shredder in many Rocky Mountain subalpine creeks, is as dependent on the autochthonous production of moss as it is on allochthonous detritus.
Comparison of daily energy expenditure of greater snow geese between two habitats
Authors: Gauthier G. , Bédard J. , Bédard Y.
Published: January 2009

We estimated the daily energy expenditure (DEE) of greater snow geese (Anser caerulescens atlanticus) on their St. Lawrence River estuary spring staging ground using time budget data. We compared DEE between two habitats: the traditionally occupied freshwater Scirpus-dominated marsh (SCI), and the recently invaded Spartina-dominated salt marsh (SPA). As greater snow geese staging at SCI have been found to accumulate larger fat reserves in the spring than those staging at SPA, we sought to explain these differences in diverging DEE patterns between the two habitats. We found that geese spent 42% more time (and energy) feeding in the marsh at SCI, but spent 61% less energy feeding in the field than at SPA. The energy spent in other activities was similar in both habitats. However, during the 6-week staging period, DEE was lower by only 4.7% at SPA (1613 kJ/day; 2.3 × basal metabolic rate (BMR) when compared with SCI (1689 kJ/day; 2.5 × BMR). This difference in DEE cannot account for the habitat-based differences in prebreeding fattening, and alternative hypotheses are examined.
The adaptive significance of dorsal spine variation in the fourspine stickleback, Apeltes quadracus, I. Geographic variation in spine number
Authors: Blouw D. M. , Hagen D. W.
Published: January 2009

The goal of our research is to investigate the adaptive significance of a polymorphism for the number of dorsal spines in Apeltes quadracus, the fourspine stickleback. One approach we take is to search for correlations between phenotypes and environments. To this end we collected Apeltes and scored environments at 570 sites in the Maritime Provinces of Canada. In this paper we describe geographic variation in spine number and evaluate how reliably it reflects genetic differentiation among sites. Morph frequencies are highly differentiated geographically. We describe four kinds of variation: relatively constant frequencies, gentle clines, steep clines, and remarkably abrupt changes (called "intrusions") where frequencies at some sites differ greatly from those at a larger number of surrounding sites. Most of the variation among sites is due to differences in the frequencies of the four- and five-spined morphs. However, a remarkable result is that the three-spined morph, which is rare or absent elsewhere in the range, reaches very high frequencies in Bras D'Or Lake. Our evidence suggests this variation among sites reflects substantial genetic differentiation. The differentiation is favorable for detecting selective agents, if indeed selection is responsible.
Intermolt cuticle and muscle growth in Tipula larvae (Insecta, Diptera)
Authors: Pritchard Gordon , Mutch Cynthia
Published: January 2009

The head capsule of larval Tipula consists of three regions: (i) a heavily sclerotized anterior region that is free from the body and carries the mouthparts, (ii) a middle region permanently fused to the invaginated cervical cuticle, and (iii) a posterior region to which cuticle is added between ecdyses. Mandibular and head protractor muscles increase in size during the intermolt period by growing in parallel with the cuticle. Increased muscle power is thereby probably achieved without molting.
Host discrimination in the aphid parasitoid Aphidius nigripes
Authors: Cloutier Conrad , Dohse Lothar A. , Bauduin France
Published: January 2009

Females of the solitary aphid parasitoid Aphidius nigripes do not consistently avoid superparasitizing their hosts, the potato aphid Macrosiphum euphorbiae. Tests were conducted in which two attacks separated by a time interval ranging from 1 to 24 h were allowed per host. No evidence of host discrimination was found when the interval was <2 h. For longer intervals, host discrimination was an increasing function of the length of the interval up to 24 h after the initial attack. Various mathematical models, permitting time-related rejection of parasitized hosts, were used to simulate the parasitoids–host distributions following two attacks. The best fitting models also had to incorporate time-dependent discrimination against hosts that had been attacked but not successfully parasitized. The results are discussed with respect to possible mechanisms of host discrimination in A. nigripes and its significance in intraspecific competition.
Orientation of procercoids of Triaenophorus crassus Forel in Cyclops bicuspidatus thomasi Forbes: effects on growth and development
Authors: Shostak Allen W. , Rosen Ronald B. , Dick Terry A.
Published: January 2009

The orientation of procercoid larvae of Triaenophorus crassus within the hemocoele of experimentally infected Cyclops bicuspidatus thomasi was evaluated between 2 and 28 days postexposure to coracidia. Short procercoids did not exhibit a preferred orientation. Procercoids tended to align with the longitudinal axis of the host as they lengthened, exhibiting a significant preference for an anterior orientation (frontal region of the procercoid anterior in the host to its oncospheral hooks). About 80% of procercoids greater than 200 μm in length were oriented anteriorly. Anterior orientation was associated with faster initial procercoid growth and development than in posteriorly oriented procercoids, but the final size and developmental state reached by days 17–28 postexposure were not influenced by orientation. The effect of orientation on procercoid growth was similar to the effect of crowding in low intensity infections. The faster growth and development of anteriorly oriented procercoids likely enhances the probability of their successful transmission.