bluuebunny/crossref_metadata_2025 huggingface dataset:
Vitiligo pathogenesis: autoimmune disease, genetic defect, excessive reactive oxygen species, calcium imbalance, or what else?
Authors: Ralf Paus Lübeck , Schallreuter K. U. , Bahadoran P. , Picardo M. , Slominski A. , Elassiuty Y. E. , Kemp E. H. , Giachino C. , Liu J. B. , Luiten R. M. , Lambe T. , Le Poole I. C. , Dammak I. , Onay H. , Zmijewski M. A. , Dell’Anna M. L. , Zeegers M. P. , Cornall R. J. , Paus R. , Ortonne J. P. , Westerhof W.
Published: November 2008

Abstract:  The pathobiology of vitiligo has been hotly disputed for as long as one remembers, and has been a magnet for endless speculation. Evidently, the different schools of thought – ranging, e.g. from the concept that vitiligo essentially is a free‐radical disorder to that of vitiligo being a primary autoimmune disease – imply very different consequences for the best therapeutic strategies that one should adopt. As a more effective therapy for this common, often disfiguring pigmentary disorder is direly needed, we must strive harder to settle the pathogenesis debate definitively – on the basis of sound experimental evidence, rather than by a war of dogmatic theories.

Recognizing, however, that it is theories which tend to guide our experimental designs and choice of study parameters, the various pathogenesis theories on the market deserve to be critically, yet unemotionally re‐evaluated. This Controversies feature invites you to do so, and to ask yourself: Is there something important or worthwhile exploring in other pathogenesis scenarios than those already favoured by you that may help you improve your own study design, next time you have a fresh look at vitiligo?

Vitiligo provides a superb model for the study of many fundamental problems in skin biology and pathology. Therefore, even if it later turns out that, as far as your own vitiligo pathogenesis concept is concerned, you have barked‐up the wrong tree most of the time, chances are that you shall anyway have generated priceless new insights into skin function along the way.
Transcatheter closure of an atrial septal defect in a newborn with aortic stenosis
Authors: Beitzke Albrecht , Zobel Gerfried , Nagel Bert , Koestenberger Martin
Published: November 2008

Aim: A newborn with valvular aortic stenosis and a 5 mm atrial septal defect (ASD) underwent emergency aortic valvotomy. The small left ventricle of the newborn with signs of fibroelastosis showed good function but a reduced compliance and caused a large left to right shunt at atrial level.

Methods and Results: As the patient became respirator‐dependant the ASD was interventionally closed with an 18 mm Amplatzer® PFO occluder. The patient could be weaned from the ventilator within two days and had an uneventful recovery.

Conclusion: Interventional closure of an ASD is possible even in the newborn period and should be considered as an alternative to surgery.
THE GOVERNMENTALIZATION OF LEARNING AND THE ASSEMBLAGE OF A LEARNING APPARATUS
Authors: Simons Maarten , Masschelein Jan
Published: November 2008

Abstract In this essay, Maarten Simons and Jan Masschelein reconsider the concepts “educationalization” and “the grammar of schooling” in the light of the overwhelming importance of “learning” today. Doubting whether these concepts and related historical‐analytical perspectives are still useful, the authors suggest the concept “learning apparatus” as a point of departure for an analysis of the “grammar of learning.” They draw on Michel Foucault’s analysis of governmentality to describe how learning has become a matter of both government and self‐government. In describing the governmentalization of learning and the current assemblage of a ”learning apparatus,” Simons and Masschelein indicate how the concept of learning has become disconnected from education and teaching and has instead come to refer to a kind of capital, to something for which the learner is personally responsible, to something that can and should be managed, and to something that must be employable. Finally, the authors elaborate how these discourses combine to play a crucial role in contemporary advanced liberalism that seeks to promote entrepreneurship.
THE WINNING WAYS OF A LOSING STRATEGY: EDUCATIONALIZING SOCIAL PROBLEMS IN THE UNITED STATES
Authors: Labaree David F
Published: November 2008

Abstract In this essay, David Labaree examines the paradox of educationalization in the American context. He argues that, like most modern Western societies, the United States has displayed a strong tendency over the years for educationalizing social problems, even though schools have repeatedly proven that they are an ineffective mechanism for solving these problems. He starts by examining the ways in which the process of educationalizing social problems is deeply grounded in American beliefs, social processes, political and organizational tensions, and structural possibilities. These include utility, individualism, optimism, professional interest, political interest, political opportunity, structural limits, and formalism. Then Labaree examines the roots of education’s failure in the role of social reform agent. Finally, he closes with an analysis of why we continue to pursue educationalization in the face of its ineffectiveness.
EDUCATIONALIZATION: ON THE APPROPRIATENESS OF ASKING EDUCATIONAL INSTITUTIONS TO SOLVE SOCIAL AND ECONOMIC PROBLEMS
Authors: Bridges David
Published: November 2008

Abstract Educationalization is a term most frequently used to indicate that government (in particular) has inappropriately imposed on educational institutions responsibility for providing the solution to some social or economic problem. In this essay David Bridges illustrates, however, the way in which educational institutions collude in this process, where they see doing so as in their interests. He also points to the way idealistically (rather than cynically) educators might seek to contribute to the wider social agenda of their age. Indeed it is arguable that there is a conceptual link between the idea of education and that of social improvement. These observations frame the question about educationalization as one concerning the appropriateness or otherwise of looking to educational institutions to solve social problems and how one might determine such appropriateness. To what extent, Bridges asks, can and should educational institutions play a role in addressing the wider social and economic political agenda? In this essay he attempts the beginning of an answer to both these questions.
Late gas accretion on to primordial minihaloes: a model for Leo T, dark galaxies and extragalactic high-velocity clouds
Authors: Ricotti Massimo
Published: November 2008

In this Letter, we revisit the idea of reionization feedback on dwarf galaxy formation. We show that primordial minihaloes with vcir < 20 km s−1 stop accreting gas after reionization, as it is usually assumed, but in virtue of their increasing concentration and the decreasing temperature of the intergalactic medium as redshift decreases below z= 3, they have a late phase of gas accretion and possibly star formation. We expect that pre-reionization fossils that evolved on the outskirts of the Milky Way or in isolation show a bimodal star formation history with 12- and <10-Gyr old population of stars. Leo T fits with this scenario. Another prediction of the model is the possible existence of a population of gas-rich minihaloes that never formed stars. More work is needed to understand whether a subset of compact high-velocity clouds can be identified as such objects or whether an undiscovered population of dark galaxies exists in the voids between galaxies.
NCME 2008 Presidential Address: The Impact of Anchor Test Configuration on Student Proficiency Rates
Authors: Fitzpatrick Anne R.
Published: November 2008

Examined in this study were the effects of reducing anchor test length on student proficiency rates for 12 multiple‐choice tests administered in an annual, large‐scale, high‐stakes assessment. The anchor tests contained 15 items, 10 items, or five items. Five content representative samples of items were drawn at each anchor test length from a small universe of items in order to investigate the stability of equating results over anchor test samples. The operational tests were calibrated using the one‐parameter model and equated using the mean b‐value method. The findings indicated that student proficiency rates could display important variability over anchor test samples when 15 anchor items were used. Notable increases in this variability were found for some tests when shorter anchor tests were used. For these tests, some of the anchor items had parameters that changed somewhat in relative difficulty from one year to the next. It is recommended that anchor sets with more than 15 items be used to mitigate the instability in equating results due to anchor item sampling. Also, the optimal allocation method of stratified sampling should be evaluated as one means of improving the stability and precision of equating results.
The Design and Development of a Closed Chamber for the in‐situ Quantification of Dryland Soil Carbon Dioxide Fluxes
Authors: HOON STEPHEN R. , THOMAS ANDREW D. , LINTON PATRICIA E
Published: November 2008

This paper describes the design features and capabilities of a portable automated in‐situ closed chamber (ISCC) for the quantification of CO2 fluxes in dryland soils where both photosynthetic and respiratory components may be associated with a cyanobacterial crust. The processes of CO2 flux in dryland soils are briefly described in order to clarify the conditions that make quantification of these fluxes problematic. The instrumentation currently available for in‐situ soil CO2 flux measurements is then reviewed demonstrating their inadequacies for the dryland environment. The ISCC described here is a member of the closed or enrichment class of soil respiration chambers. The ISCC, however, features an optical window possessing high (>90%) transmission in the photosynthetic active region (PAR) of the solar irradiance spectrum, permitting observations of photosynthesis. The ISCC possesses automatic venting and purging so that gaseous concentrations inside the chamber do not change from ambient sufficiently to significantly affect diffusion. The ISCC features both active and passive cooling employing internal solid‐state Peltier coolers and external aluminised Mylar respectively. This avoids severe disturbance of the microclimate within the chamber due to admission of high fluxes of PAR and permits in‐situ operation under a wide range of ambient field temperatures (~ −5 to 40°C). Sensors internal to the chamber monitor temperature, relative humidity, irradiance and pressure. In this implementation the ISCC is coupled to a portable gas chromatograph (Agilent GC‐3000) to sample the chamber atmosphere. Indicative data for Kalahari Sand soils of Botswana are presented as an illustration of the general performance characteristics.
Human Adaptive Responses to Catastrophic Landscape Disruptions During the Holocene at Numundo, PNG
Authors: PARR J.F. , BOYD W.E. , HARRIOTT V. , TORRENCE R.
Published: November 2008

Prehistoric land use and social activity in West New Britain, PNG, are well documented, although the landscapes – largely shaped by catastrophic volcanic eruptions – in which these took place, and the relationships people had with these landscapes, are poorly understood. We define the evolving landscape at Numundo, from prior to the Witori‐Kimbe 2 eruption (W‐K2, ca. 3600 BP) to after the Witori‐Kimbe 4 eruption (W‐K4, ca. 1400 BP), using fossil phytolith and coral evidence at eight archaeological sites to provide environmental evidence of the human responses to periodic catastrophic events. From ca. 5900 to 3600 BP, all the sites were coastal and disturbed. Early disturbance reflected natural forest recovery after W‐K1 (ca. 5900 BP), whereas the later landscape was largely shaped by human activity. In contrast, forest regrowth was limited after W‐K2 and open environments typical of human activity with a mosaic of regenerating, disturbed and managed vegetation, persisted until W‐K3. Environmental recovery from W‐K3 and W‐K4 (ca. 1700 BP and ca. 1400 BP) differed completely, reflecting severity of the volcanism and the short time between eruptions. The landscape after W‐K3 was largely a naturally recovering landscape, in contrast to effective vegetation recovery and significant human exploitation of the landscape – again a mosaic of regenerating, disturbed and managed vegetation – after W‐K4. The social history is one in which people evolved increasingly flexible land‐use practices, enabling them to re‐settle this periodically disrupted landscape, and to take advantage of an increasingly broad range of habitats suitable for cultivation. The human response to this highly dynamic landscape represents a close relationship between social and natural processes, as people became increasingly better at re‐settling an unpredictably disrupted landscape; both the social and environmental processes within this landscape become equally influential and instrumental in shaping the effects of the other.
MODIS‐derived NDVI Characterisation of Drought‐Induced Evergreen Dieoff in Western North America
Authors: YUHAS ANDREW N. , SCUDERI LOUIS A.
Published: November 2008

Vegetation stress or mortality can be the result of many factors including drought‐induced water deficit, insect infestations and failures of, or fluctuations in, precipitation sources typical to an area. Reduction of cover and reduced health are identifiable in remotely‐sensed multispectral satellite images. A suite of images from NASA's MODIS sensor was used to calculate the Normalised Difference Vegetation Index (NDVI) during the 2000–2006 North American growing seasons. Fluctuations in NDVI over this period show a significant decline in vegetative health in the region with specific areas showing changes linked to moisture sources, prevailing wind patterns, slope aspect and solar radiation receipt. Ground‐truthing of these areas has confirmed the extent and magnitude of the dieoff signal. Historically, dieoff has been reversed through regeneration as climate conditions return to a normal regime. However, quantification of recent vegetative change in western North America suggests that the degree of change may be too severe for regrowth to occur and may have far‐reaching impacts on a scale unseen in modern times. The loss of vegetative habitat and native species in semi‐arid regions and lack of regeneration in these marginal ecosystems due to prolonged drought are growing global problems. Similar drought stress impacts on marginal ecotypes have also been observed in semi‐arid regions of Australia, South America, Asia and Africa. Observations of the spatial pattern of temperate forest vegetation globally can be used to develop a precise picture of vegetative health in these regions and how they are reacting to global climate change.
A metapopulation model for the introgression from genetically modified plants into their wild relatives
Authors: Meirmans Patrick G. , Bousquet Jean , Isabel Nathalie
Published: November 2008

Most models on introgression from genetically modified (GM) plants have focused on small spatial scales, modelling gene flow from a field containing GM plants into a single adjacent population of a wild relative. Here, we present a model to study the effect of introgression from multiple plantations into the whole metapopulation of the wild relative. The most important result of the model is that even very low levels of introgression and selection can lead to a high probability that the transgene goes to fixation in the metapopulation. Furthermore, the overall frequency of the transgene in the metapopulation, after a certain number of generations of introgression, depends on the population dynamics. If there is a high rate of migration or a high rate of population turnover, the overall transgene frequency is much higher than with lower rates. However, under an island model of population structure, this increased frequency has only a very small effect on the probability of fixation of the transgene. Considering these results, studies on the potential ecological risks of introgression from GM plants should look not only at the rate of introgression and selection acting on the transgene, but also at the metapopulation dynamics of the wild relative.
Is exfoliation syndrome a sign of systemic vascular disease?
Authors: Tarkkanen Ahti
Published: November 2008

Exfoliation syndrome (ES) is an age‐related disorder in which greyish‐white flakes accumulate in different tissues in the anterior eye. Its pathogenesis is not completely known, but it results in electron‐dense microfibrils. The finding that these can be seen outside the eye in many visceral organs inspired the theory that ES might be a part of a generalized disorder. It was postulated that ES might contribute to increased morbidity, mainly of systemic vascular diseases. This review is a summary of the existing knowledge. The prevalence of arterial hypertension (AHT) in elderly populations is > 30%. No differences have been found in the frequency of AHT among patients with ES or exfoliative glaucoma (EG) compared with those with primary open‐angle glaucoma (POAG) or no ES. There are conflicting reports of frequencies of ischaemic heart disease (IHD). A recent registry‐based study that used uniform criteria for IHD found no difference in the rate of IHD between patients with EG and those with POAG. However, findings of elevated homocysteine levels in the plasma and aqueous humour of patients with ES or EG suggest an increased vascular risk. No studies have yet been conducted to assess possible links between ES and systemic vascular diseases. In a single‐blind study, ES was associated with abdominal aortic aneurysm, but this was not found in a large, cross‐sectional investigation. The frequency of ES in patients with diabetes mellitus (DM) is only about half of that when compared in patients with no ES or with POAG. This finding warrants further studies. Molecular genetics research has found no common denominator for ES and the vascular diseases. There is no evidence that ES or EG are related to increased mortality for cardiovascular diseases. Further large‐scale, randomized clinical studies are required. At present there are no known medical indications that infer an increased systemic vascular risk or imply a need for the complete internal medical examination of a symptom‐free patient with newly diagnosed ES in the eye.
Considerations on fundamental issues in establishing a universal coverage system for health in China
Authors: Lei Hai Chao
Published: November 2008

This study discusses basic health services in China. In this study common sense and international experience in establishing a high‐performing health system were introduced. Five components are identified: basic qualified human resources for health; basic infrastructure; essential medicines; essential technology and procedures; and basic service pathways. Recommendations were presented based upon the Chinese situation. They are: increase public financing and lower private out‐of‐pocket payment for services; revitalize the functions of public facilities; merge different health financing schemes; co‐ordinate public fiscal and pricing policies; prioritize public financing to preventive and primary healthcare; establish and strengthen the partnership between public and private facilities and insurance schemes; and re‐organize the administrative system in health‐based upon the rules of simplicity, unity, and efficiency.
From randomized controlled trials to evidence grading schemes: current state of evidence‐based practice in social sciences
Authors: Boruch Robert , Rui Ning
Published: November 2008

With the advance of web search and navigation technology, enormous amount of information, non‐information, and misinformation may be obtained in milliseconds in response to questions about ‘what works’ in social sciences. Today, policy makers in non‐medical public service arenas are under increasing pressure to make sound decisions based on scientific evidence. Some of these decisions are a matter of legal requirement. This paper shows how such movements are closely aligned with the evolution of organizations that develop and apply evidence standards and evidence grading schemes within the social science communities. The current state of evidence‐based practice in social sciences is examined by reviewing the latest development of randomized trials and evidence grading schemes in the fields of education, criminal justice, and social welfare. Studies conducted under the auspices of the Campbell Collaboration and What Works Clearinghouse are used to illustrate ingredients of evidence grading schemes, graphic display of results of systematic reviews, and discrepancies of evidence derived from randomized trials and non‐experimental trials. Furthermore, it is argued that the use of evidence on ‘what works’ depends on the potential users' awareness, understanding of the evidence, as well as their capacity and willingness to use it. Awareness and understanding depends on the world wide web and its augmentations, while capacity and willingness depends more on incentives to use good evidence and on political and ethical values. Implications for the future development of evidence grading organizations are discussed.
The protective role of Hepatopoietin Cn on liver injury induced by carbon tetrachloride in rats*
Authors: Cui Chun‐Ping , Wei Ping , Liu Yang , Zhang Da‐Jin , Wang Li‐Sheng , Wu Chu‐Tse
Published: November 2008

Background:  Hepatopoietin Cn (HPPCn) is a member of the leucine‐rich acidic nuclear protein family (LANP), and studies of partially hepatectomized (PH) mice show that levels of HPPCn mRNA increase following liver injury. Furthermore, the recombinant human protein (rhHPPCn) was shown to stimulate hepatic DNA synthesis and activate signaling pathways involved in hepatocyte proliferation in vitro and in vivo.

Aim:  The aim of the study was to evaluate the protective effect of rhHPPCn on liver injury and fibrosis induced by carbon tetrachloride (CCl4) injection.

Methods:  Wistar rats weighing 200 g were given a single and repeated intraperitoneal injections of CCl4. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity in rat serum were measured using biochemical assay. Hepatic hydroxyproline (Hyp) level was determined in the hydrolysates of liver samples. Immunostaining and Masson's trichrome staining were conducted to evaluate hepatocyte proliferation and fibrosis.

Results:  The results showed that exogenous rhHPPCn could alleviate hepatocyte necrosis and protect the liver from the development of fibrotic lesions by proliferation stimulation. Additionally, HPPCn could reduce ALT/AST levels in rat serum following single and repeated CCl4 injection.

Conclusion:  It was suggested that HPPCn could protect hepatocytes from injury induced by CCl4 as a proliferation stimulator.
AMPylation of Rho GTPases by
Vibrio
VopS Disrupts Effector Binding and Downstream Signaling
Authors: Yarbrough Melanie L. , Li Yan , Kinch Lisa N. , Grishin Nick V. , Ball Haydn L. , Orth Kim
Published: November 2008

The
Vibrio parahaemolyticus
type III effector VopS is implicated in cell rounding and the collapse of the actin cytoskeleton by inhibiting Rho guanosine triphosphatases (GTPases). We found that VopS could act to covalently modify a conserved threonine residue on Rho, Rac, and Cdc42 with adenosine 5′-monophosphate (AMP). The resulting AMPylation prevented the interaction of Rho GTPases with downstream effectors, thereby inhibiting actin assembly in the infected cell. Eukaryotic proteins were also directly modified with AMP, potentially expanding the repertoire of posttranslational modifications for molecular signaling.
Preparation of Au-Pt Nanostructures on Highly Oriented Pyrolytic Graphite Surfaces by Pulsed Laser Deposition and Their Characterization by XPS and AFM Methods
Authors: Plšek Jan , Janda Pavel , Bastl Zdeněk
Published: November 2008

Au-Pt nanostructures on highly oriented pyrolytic graphite (HOPG) were prepared by irradiating bimetallic target under ultrahigh vacuum with pulsed radiation of Nd:YAG laser. The deposited nanostructures were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The measured spectra of Au (4f) and Pt (4f) photoelectrons of laser deposits were composed of two overlapping doublets. Analysis of images obtained from AFM revealed bimodal particle size distribution and presence of few large particles. In agreement with AFM images of the deposit we attributed a two doublet structure of Au (4f) and Pt (4f) spectra to bimodal nanoparticle size distribution. Carbon KLL Auger electron spectra revealed formation of defects in the superficial layers of HOPG by impinging metal ions accompanied by appearance of sp3 hybridized carbon atoms. The dependence of Au (4f) and Pt (4f) core level binding energies on the amount of metals deposited and formation of bimetallic nanoparticles are discussed.
Thermodynamic Data of Iodine Reactions Calculated by Quantum Chemistry. Training Set of Molecules
Authors: Mečiarová Katarína , Cantrel Laurent , Černušák Ivan
Published: November 2008

This paper focuses on the reactivity of iodine which is the most critical radioactive contaminant with potential short-term radiological consequences to the environment. The radiological risk assessments of 131I volatile fission products rely on studies of the vapour-phase chemical reactions proceeding in the reactor coolant system (RCS), whose function is transferring the energy from the reactor core to a secondary pressurised water line via the steam generator. Iodine is a fission product of major importance in any reactor accident because numerous volatile iodine species exist under reactor containment conditions. In this work, the comparison of the thermodynamic data obtained from the experimental measurements and theoretical calculations (approaching "chemical accuracy") is presented. Ab initio quantum chemistry methods, combined with a standard statistical-thermodynamical treatment and followed by inclusion of small energetic corrections (approximating full configuration interaction and spin-orbit effects) are used to calculate the spectroscopic and thermodynamic properties of molecules containing atoms H, O and I. The set of molecules and reactions serves as a benchmark for future studies. The results for this training set are compared with reference values coming from an established thermodynamic database. The computed results are promising enough to go on performing ab initio calculations in order to predict thermo-kinetic parameters of other reactions involving iodine-containing species.
Chronic obstructive pulmonary disease mortality in railroad workers
Authors: Hart J E , Laden F , Eisen E A , Smith T J , Garshick E
Published: November 2008

Background:

There is little information describing the risk of non-malignant respiratory disease and occupational exposure to diesel exhaust.

Methods:

US railroad workers have been exposed to diesel exhaust since diesel locomotives were introduced after World War II. In a retrospective cohort study we examined the association of chronic obstructive pulmonary disease (COPD) mortality with years of work in diesel-exposed jobs. To examine the possible confounding effects of smoking, multiple imputation was used to model smoking history. A Cox proportional hazards model was used to estimate an incidence rate ratio, adjusted for age, calendar year, and length of follow-up after leaving work (to reduce bias due to a healthy worker survivor effect).

Results:

Workers in jobs with diesel exhaust exposure had an increased risk of COPD mortality relative to those in unexposed jobs. Workers hired after the introduction of diesel locomotives had a 2.5% increase in COPD mortality risk for each additional year of work in a diesel-exposed job. This risk was only slightly attenuated after adjustment for imputed smoking history.

Conclusions:

These results support an association between occupational exposure to diesel exhaust and COPD mortality.
The Quantification of Stream Drift
Authors: Allan J. David , Russek Estelle
Published: November 2008

Although the purpose of many drift studies is to describe quantitatively the abundance of drifting invertebrates and make comparisons between seasons or sites, almost no investigations have employed replicate sampling. We analyzed drift collections from a Rocky Mountain stream in order to investigate the variability of drift sampling. The data were normalized and the variances stabilized for each taxon examined by data transformation. The fourth root transformation was favored for five taxa and the logarithmic transformation for three. Using the 95% confidence limits on 24-h drift density for an abundant mayfly (Baetis bicaudatus), we found that six to seven replicates are required to obtain 95% CL ± 50% of the mean. Drift sampling appears to require fewer replicates than benthic sampling for comparable precision. Investigators may fail to replicate drift samples because they elect to sample frequently over 24 h in order to quantify the diel periodicity of drift. However, when comparison between sites or dates is the principal goal, we recommend that the effort normally put into frequent sampling over 24 h be invested instead in replicated sampling just after dark, when drift normally is greatest. When we regressed drift from the first night sample against total drift from the remainder of the 24-h period, 60–90% of the variation in the latter was predicted from the single nighttime sample. Thus, little information appears to be lost by this recommended procedure.
Modelling Winter Oxygen Depletion Rates in Ice-Covered Temperate Zone Lakes in Canada
Authors: Babin J. , Prepas E. E.
Published: November 2008

Winter oxygen depletion rates (WODR) (g O2∙m−2∙d−1) were determined for 13 lakes in central Alberta during the winter of 1982–83. Although dissolved oxygen decreased in all lakes for the first 3.5 mo after freeze-up, the decreases were nonlinear. The highest WODR were observed just after freeze-up. The nonlinear WODR were significantly correlated with two estimates of lake productivity (i.e. total phosphorus and chlorophyll a, P < 0.05) but were not significantly correlated with morphometry (e.g. mean depth). When the WODR from the Albertan lakes were treated as linear, to enable a comparison with other studies, correlations were found between WODR and morphometry, and WODR and estimates of summer productivity. These relationships were significantly different from observations by previous investigators who worked on ice-covered lakes in two other regions. When data from other ice-covered lakes were combined with this study, WODR were best predicted from a combination of mean summer TP (TPsu in mg∙m−2) in the euphotic zone and mean depth ([Formula: see text] in m):[Formula: see text]The above equation permits the prediction of WODR for a greater range of lake types than previous models.
Gas Supersaturation as a Cause of Early Spring Mortality of Stocked Trout
Authors: Mathias Jack A. , Barica Jan
Published: November 2008

Rainbow trout (Salmo gairdneri) fingerlings, stocked through the ice of shallow prairie lakes, experienced high mortality even though algal photosynthesis had returned whole-lake oxygen concentrations to normal levels prior to ice melting. Fish caged beneath the ice showed symptoms of asphyxiation or gas bubble disease, depending on depth. Asphyxiation occurred at oxygen concentrations below 4 mg/L We identify total dissolved gas tension as the primary cause of bubble disease and resulting mortality, and demonstrate the relative contribution of oxygen and nitrogen to total gas tension. Significant mortalities were associated with oxygen relative partial pressures (gas partial pressure relative to total hydrostatic pressure) exceeding 0.2, but only when accompanied by nitrogen relative partial pressures above 1.1. Total relative gas tension under these circumstances exceeded 1.3. An increase in nitrogen partial pressures over the winter was attributed to the physical freeze-out of nitrogen from the ice in shallow lakes where reduction of lake volume due to ice formation is substantial.
Experimental and Field Evidence for Inter- and Intraspecific Competition in Two Freshwater Fishes
Authors: Hanson John Mark , Leggett William C.
Published: November 2008

Direct evidence for intra- and interspecific competition in fishes was obtained by manipulating populations of yellow perch (Perca flavescens) and pumpkinseed (Lepomis gibbosus) stocked into littoral zone enclosures. Stocking densities were above, below, and equal to measured littoral zone fish biomass. There were no significant differences in mean percent weight change at given densities among repeated experiments (each of 14-d duration). In experiments testing for intraspecific competition, all fish reared at low density gained weight, all fish reared at high density lost weight, and mean weight change at natural density did not differ from 0.0. In experiments testing for interspecific competition, growth of pumpkinseed did not differ from growth of pumpkinseed reared alone at equivalent densities whereas growth of yellow perch was depressed relative to growth of yellow perch reared alone at equivalent densities. These growth changes did not result from behavioural interactions. We conclude that (a) inter- and intraspecific competition for food is significant at natural fish densities and (b) pumpkinseed are superior to perch when competing for food. A marked reduction in yellow perch growth in Lake Memphremagog between 1972 and 1983, coincident with a major increase in pumpkinseed abundance, is consistent with these findings and our interpretations.
Initial Egg Weight, Time to Maximum Alevin Wet Weight, and Optimal Ponding Times for Chinook Salmon (Oncorhynchus tshawytscha)
Authors: Rombough Peter J.
Published: November 2008

Eggs of chinook salmon (Oncorhynchus tshawytscha) were segregated into eight size groups (range 163–437 mg) and incubated at 5, 7.5, 10, and 12.5 °C. The time required to reach maximum alevin wet weight (MAWW) varied significantly (p < 0.01) both with mean incubation temperature (T °C) and with initial egg weight (W mg). A good (R2 = 98.4%, n = 21) prediction of days postfertilization to MAWW (D) is given by[Formula: see text]Optimal ponding times are closely associated with the attainment of MAWW and can be estimated using this equation. Data relating mean incubation temperatures (T) to actual ponding time were collected from 17 hatcheries throughout British Columbia. The equation[Formula: see text]where D′ is days postfertilization to ponding, provided the best fit to the data (R2 = 97.5%, n = 85). Hatchery ponding times were not significantly different from times to MAWW predicted for 200-mg eggs.
Variation in Length and Body Depth of Pink Salmon (Oncorhynchus gorbuscha) and Chum Salmon (O. keta) in Southern British Columbia
Authors: Beacham Terry D. , Murray Clyde B.
Published: November 2008

The magnitude of within-stock variability of postorbital–hypural length and body depth was investigated for spawning pink salmon (Oncorhynchus gorbuscha) and chum salmon (O. keta) stocks. Variability of postorbital–hypural length and body depth of male pink salmon, all maturing at 2 yr of age, was greater than that for male chum salmon, maturing at ages of 3–5 yr. Female pink salmon were less variable for the two characters than all ages of female chum salmon, equally variable when only age 3 or age 4 female chum salmon were considered, and more variable in comparison with age 5 female chum salmon. Males were more variable for each character than females for both species. Small males of both species tend to resemble females when body depths are compared. It is suggested that small males mimic females to reduce aggression from larger males and gain access to spawning females.
Responses of Sockeye Salmon (Oncorhynchus nerka) to Fertilization of British Columbia Coastal Lakes
Authors: Hyatt Kim D. , Stockner John G.
Published: November 2008

Addition of nitrogen and phosphorus fertilizer to several British Columbia coastal lakes has resulted in increased autotrophic and heterotrophic production and larger standing stocks of zooplankton. These changes at the primary and secondary trophic levels are reflected by increased in-lake growth of juvenile sockeye salmon (Oncorhynchus nerka) and larger outmigrant smolts. Evidence is presented that smolt size changes in fertilized lakes will lead to increases in the harvestable surplus of sockeye adults by promoting both increases in marine survival and an earlier age-at-return to the fishery.
Dispersion and Retention of Anadromous Rainbow Smelt (Osmerus mordax) Larvae in the Middle Estuary of the St. Lawrence River
Authors: Quellet Patrick , Dodson Julian J.
Published: November 2008

The vertical and horizontal distribution of anadromous rainbow smelt (Osmerus mordax) larvae from hatching in their natal river to their occupation of nursery areas in the middle estuary of the St. Lawrence River was documented to describe the mechanism responsible for the retention of smelt larvae in this area. Peaks of larval abundance observed downstream of the spawning grounds indicate a 24-h periodicity in hatching and the introduction of larvae into the riverine circulation. No retention of larvae was observed between the spawning ground and the downstream portion of the natal river. Our evidence indicates daytime accumulation of larvae at the mouth of the natal river, possibly resulting from the negative phototaxis exhibited by small smelt larvae. Patches of smelt larvae were incorporated into the St. Lawrence estuarine water mass once every 24 h at night following high tide. The subsequent downstream transport of larvae in the St. Lawrence estuary appears slower than the advection of the water mass due to the tendency of larvae to remain deeper in the water column during ebb tides and to concentrate near the surface during flood tides. Smelt larvae are transported from the south shore to the partially mixed northern portion of the middle estuary which represents the principal zone of larval smelt accumulation. We propose that the vertical displacements exhibited by smelt larvae in combination with the two-layer circulation system of the northern middle estuary results in the retention of smelt larvae in this region.
Aspects of the Biology of Pseudocarcinonemertes homari and Its Association with the American Lobster, Homarus americanus
Authors: Aiken D. E. , Waddy S. L. , Uhazy L S.
Published: November 2008

Pseudocarcinonemertes homari can reproduce on and destroy the egg mass of both the American (Homarus americanus) and the European lobster (H. gammarus) but does not appear to be a problem for brachyuran species. The eggs of P. homari are subspherical, average 251 × 260 μm, and are contained in individual compartments in a membranous brood sac that is attached to the lobster abdomen or egg mass. An average of 39 eggs occur in a brood sac. Newly hatched larvae are ciliated, lack anterior and posterior tufts, cirri or flagella, and are retained in the brood sac. Larval development is direct, and there is no free-swimming stage. After the larvae break out of the brood sac they join the adults and juveniles on the lobster egg mass. Many lobsters gradually remove infested eggs, but on those that do not, the nemertean population can increase to more than 14 000 individuals. After the lobster eggs are destroyed, the nemerteans disperse. Some form mucoid aggregations at protected sites on the exoskeleton; others move to the branchial chamber and gills or transfer to other lobsters. Reproduction occurs almost exclusively on the lobster egg mass, but P. homari appears capable of reproducing on lobster gills if denied access to lobster eggs for extended periods.
Strontium Labelling for Verifying Daily Growth Increments in the Statolith of the Short-Finned Squid (Illex illecebrosus)
Authors: Hurley Geoffrey V. , Odense Paul H. , O'Dor Ron K. , Dawe Earl G.
Published: November 2008

Shrimp soaked in strontium chloride solution were fed to short-finned squid (Illex illecebrosus). The strontium was deposited in the statolith of the squid where, with the use of an electron microprobe, it was detectable as a distinct band on the ground surface of the statolith. Strontium X-ray maps and corresponding back-scattered electron images in the atomic contrast mode were obtained. Use was made of a strontium X-ray line profile to discriminate between markings deposited only 2 d apart. Micrographs were compared with light micrographs to verify the daily growth increments.
COMPARISON BETWEEN GLOBAL, CLASSICAL DOMAIN DECOMPOSITION AND LOCAL, SINGLE AND DOUBLE COLLOCATION METHODS BASED ON RBF INTERPOLATION FOR SOLVING CONVECTION-DIFFUSION EQUATION
Authors: GUTIERREZ GAIL , FLOREZ WHADY
Published: November 2008

This work presents a performance comparison of several meshless RBF formulations for convection-diffusion equation with moderate-to-high Peclet number regimes. For the solution of convection-diffusion problems, several comparisons between global (full-domain) meshless RBF methods and mesh-based methods have been presented in the literature. However, in depth studies between new local RBF collocation methods and full-domain symmetric RBF collocation methods are not reported yet. The RBF formulations included: global symmetric method, symmetric double boundary collocation method, additive Schwarz domain decomposition method (DDM) when it is incorporated into two anterior approaches, and local single and double collocation methods. It can be found that the accuracy of solutions deteriorates as Pe increases, if no special treatment is used. From the numerical tests, it seems that the local methods, especially the derived double collocation technique incorporating PDE operator, are more effective than full domain approaches even with iterative DDM in solving moderate-to-high Pe convection-diffusion problems subject to mixed boundary conditions.
TIGHT-BINDING METHOD FOR QUANTUM-CONFINEMENT ENERGY CALCULATIONS IN THE CdSe/ZnSe MULTIPLE QUANTUM WELLS
Authors: TIT NACIR , OBAIDAT IHAB M.
Published: November 2008

We present an efficient method to calculate the quantum-confinement energy of charge carriers in the ( ZnSe )M( CdSe )N (001) multiple quantum wells (MQW). The method is based on the 3D empirical sp3s* tight-binding models, which include the spin-orbit coupling. The method can handle large systems while it takes account of the band mixing caused by the strain and confinement. In these perspectives, it proves itself more reliable than the traditional effective-mass approach (EMA) by further generating more relevant information about the quantum states localized within the wells; in particular, the number of bound states and their energy levels and their corresponding wavefunctions were obtained based on more realistic physical models. The quantum-confinement energy, bandgap energy, and band structures are studied versus the CdSe well width (N). The results are found to be comparable with those experimentally obtained using photoluminescence.
CORRELATIONS BETWEEN POLITICAL PARTY SIZE AND VOTER MEMORY: A STATISTICAL ANALYSIS OF OPINION POLLS
Authors: ANDRESEN CHRISTIAN A. , HANSEN HENNING F. , HANSEN ALEX , VASCONCELOS GIOVANI L. , ANDRADE JOSÉ S.
Published: November 2008

This paper describes the application of statistical methods to political polling data in order to look for correlations and memory effects. We propose measures for quantifying the political memory using the correlation function and scaling analysis. These methods reveal time correlations and self-affine scaling properties, respectively, and they have been applied to polling data from Norway. Power-law dependencies have been found between correlation measures and party size, and different scaling behaviors have been found for large and small parties.
PHASE TRANSITION IN THE ISING MODEL ON LOCAL-WORLD EVOLVING NETWORKS
Authors: QIANG WEI , HU GUANGDAO , ZHAO PENGDA
Published: November 2008

We study the critical behavior of the Ising model on the local-world evolving network. Monte Carlo simulations with the standard Metropolis local update algorithms are performed extensively on the network with different parameters. Ising spins put onto network vertices exhibit an effective phase transition from ferromagnetism to paramagnetism upon heating. The critical temperature has been demonstrated to increase linearly with the average degree of the network as TC ~ 〈k〉. Simulation results on local-world evolving networks with various parameters show logarithmical relationships of the critical temperature with the size of the local world as TC ~ ln (ml), and with the size of the network as TC ~ ln (N), respectively. The latter is the generalization of the conclusion for the Ising model on the Barabási–Albert scale-free network, a limiting case of the local-world evolving network.
EXPERT SYSTEM FOR ANALYSIS OF SPECTRA IN NUCLEAR METROLOGY
Authors: PETROVIĆ IVAN , PETROVIĆ V. , KRSTIĆ D. , NIKEZIĆ D. , BOČVARSKI V.
Published: November 2008

In this paper is described an expert system (ES) developed in order to enable the analysis of emission spectra, which are obtained by measurements of activities of radioactive elements, i.e., isotopes, actually cesium. In the structure of those spectra exists two parts: first on lower energies, which originates from the Compton effect, and second on higher energies, which contains the photopeak. The aforementioned ES is made to perform analysis of spectra in whole range of energies. Analysis of those spectra is very interesting because of the problem of environmental contamination by radio nuclides.
THE CONTINUUM AND INTERFERENCE EFFECT IN $e^+e^-\to D^0\bar{D}^0$, D+D- Processes
Authors: YANG MAO-ZHI
Published: November 2008

In the e+e- annihilation processes [Formula: see text], D+D- near or above the threshold of [Formula: see text], there are not only the resonance contribution [Formula: see text], D+D-, but also the continuum contribution through virtual photon directly [Formula: see text], D+D-. The amplitudes through virtual photon directly and through resonance can interfere seriously. We consider the continuum and interference effect in the [Formula: see text] production process in e+e- annihilation. We find that the effect is significant near and above the threshold of the [Formula: see text] mesons.
EXACTNESS IN THE PATH INTEGRAL OF THE COULOMB POTENTIAL IN ONE SPACE DIMENSION
Authors: SAKODA SEJII
Published: November 2008

We solve time-sliced path integrals of one-dimensional Coulomb system in an exact manner. In formulating path integrals, we make use of the Duru–Kleinert transformation with Fujikawa's gauge theoretical technique. Feynman kernels in the momentum representation both for bound states and scattering states will be obtained with clear pole structure that explains the exactness of the path integral. The path integrals presented here can be, therefore, evaluated exactly by making use of Cauchy's integral theorem.
POWER SPECTRUM OF AN INTERFEROMETER SIGNAL IN EXPERIMENTS ON SOUNDING OF A TURBULENT WATER STREAM WITH PULSATING VELOCITY
Authors: V'UGIN PAVEL N. , GAVRILENKO VLADIMIR G. , KUSTOV LEONID M. , MART'ANOV ALEKSANDR I. , NECHAEVA MARIA B.
Published: November 2008

The paper is related to studies of a turbulent medium by the sounding method with the interferometric reception. We performed a theoretical analysis of a multiplicative interferometer response to noise quasi-monochromatic emission, disturbed by a turbulent water stream. The effect of turbulent pulsations of the stream velocity on output interferometer signal was considered. Spectral analysis of the output interferometer signal allowed to perform the diagnostics of the propagation media. Particularly, it was shown, that the interferometer power spectrum carries information on the spatial spectrum of fluctuations of cavity bubbles concentration and on the average stream velocity. The theoretical evidence has been compared with the results of interferometric experiments on ultrasonic sounding of the water stream inside a pipe.