bluuebunny/crossref_metadata_2025 huggingface dataset:
Histological and immunohistochemical analysis of initial and early osseous integration at chemically modified and conventional SLA® titanium implants: preliminary results of a pilot study in dogs
Authors: Schwarz Frank , Herten Monika , Sager Martin , Wieland Marco , Dard Michel , Becker Jürgen
Published: May 2007

Objectives: The aim of the present pilot study was to investigate initial and early tissue reactions to modified (mod) and conventional sand‐blasted, large grit and acid‐etched (SLA) titanium implants.

Material and methods: Implantation of modSLA and SLA implants was performed bilaterally in both the mandible and maxilla of dogs. The animals were sacrificed after a healing period of 1, 4, 7 and 14 days, respectively. Peri‐implant tissue reactions were assessed in non‐decalcified tissue sections using conventional histology (Toluidine blue‐TB and Masson Goldner Trichrome stain‐MG) and immunohistochemistry using monoclonal antibodies to transglutaminase II (TG) (angiogenesis) and osteocalcin (OC). Bone density (BD) and bone to implant contact (BIC) were assessed histomorphometrically.

Results: Day 1 revealed an early TG antigen reactivity in the provisional fibrin matrix adjacent to both implant surfaces. Day 4 was characterized by the formation of a collagen‐rich connective tissue (MG), which revealed the first signs of OC synthesis adjacent to modSLA surfaces. Immunohistochemical staining for TG revealed a direct correlation between angiogenesis and new bone formation, which was clearly identifiable after 7 days by means of increasing BD, BIC and OC values. After 14 days, modSLA surfaces seemed to be surrounded by a firmly attached mature, parallel‐fibered woven bone.

Conclusions: Within the limits of the present study, it might be concluded that the combination of immunohistochemical and conventional histological stainings in non‐decalcified tissue sections is a valuable technique to evaluate the initial and early stages of wound healing around endosseous titanium implants.
Mast cells in the pathogenesis of rheumatic diseases and as potential targets for anti‐rheumatic therapy
Authors: Eklund Kari K.
Published: May 2007

Summary:  Increasing evidence suggests that mast cells (MCs), in addition to acute allergic reactions, are involved in the pathogenesis of chronic inflammatory diseases and in particular in rheumatoid arthritis (RA). MCs reside in connective tissues and in synovial tissue of joints. They produce an array of proinflammatory mediators, tissue destructive proteases, and cytokines, most prominently tumor necrosis factor‐α, which is one of the key cytokines in the pathogenesis of RA. MCs may also participate in the development of secondary or amyloid A amyloidosis, as the partial degradation of the serum amyloid A (SAA) protein by MCs leads to the generation of a highly amyloidogenic N‐terminal fragment of SAA. MCs may contribute to the pathogenesis of connective tissue diseases, scleroderma, vasculitic syndromes, and systemic lupus erythematosus, although the data available are limited. Inhibition of the most important growth factor receptor of human MCs, c‐Kit, by the selective tyrosine kinase inhibitor imatinib mesylate, induces apoptosis of synovial tissue MCs. As MCs are long‐lived cells, induction of their apoptosis could be a feasible approach to inhibit their functions. Preliminary findings suggest that a drug that inhibits c‐Kit could have anti‐rheumatic activity in the treatment of patients with RA and spondyloarthropathies.
Effects of combination of melatonin and dexamethasone on secondary injury in an experimental mice model of spinal cord trauma
Authors: Genovese Tiziana , Mazzon Emanuela , Crisafulli Concetta , Esposito Emanuela , Di Paola Rosanna , Muià Carmelo , Di Bella Paolo , Bramanti Placido , Cuzzocrea Salvatore
Published: May 2007

Abstract: This study investigates the effects of combination therapy with melatonin and dexamethasone on the degree of spinal cord injury caused by the application of vascular clip in mice. Spinal cord injury in mice resulted in severe trauma, characterized by edema, neutrophil infiltration, and apoptosis (measured by terminal deoxynucleotidyltransferase‐mediated UTP end labeling staining, and immunoreaction of Bax, Bcl‐2, and Fas Ligand). Infiltration of the spinal cord tissue with neutrophils (measured as increase in myeloperoxidase activity) was associated with enhanced immuno‐ histochemical and functional alterations revealed, respectively, by an increased of tumor necrosis factor (TNF)‐αimmunoreactivity, NOS as well as nitrotyrosine and loss of hind leg movement in spinal cord injury (SCI)‐operated mice. In contrast, the degree of neutrophil infiltration at different time points, cytokine expression, histologic damage iNOS expression, apoptosis, was markedly reduced in the tissues obtained from SCI‐treated mice with the combination therapy, and the motor recovery was also ameliorated. No anti‐inflammatory effect was observed in animals treated with melatonin (10 mg/kg) or with dexamethasone (0.025 mg/kg) alone. This study shows that the combination therapy with melatonin and dexamethasone reduces the degree of secondary damage associated with spinal cord injury in mice, and supports the possible use of melatonin in combination with steroids to reduce the dose and the side effects related with the use of steroids for the management of inflammatory disease.
Effect of high environmental temperatures on ascorbic acid, sulfhydryl residue and oxidized lipid concentrations in plasma of dairy cows
Authors: TANAKA Masahito , KAMIYA Yuko , KAMIYA Mitsuru , NAKAI Yutaka
Published: May 2007

Information on oxidative stress under hot conditions from the levels of cells to organs and the whole body has accumulated in the last decades. Although a hot climate decreased dairy performance, changes of oxidative stress markers under hot conditions have remained obscure. Therefore, the effect of high environmental temperature on ascorbic acid, sulfhydryl (SH) residue and oxidized lipids concentrations in plasma from a total of 128 dairy cows was investigated. The monthly average maximum day temperature varied from 9.2°C in January to 32°C in August of 2004 in this institute. High ambient temperatures increased the rectal temperature of dairy cows up to 39.3°C in August. One of the reducing equivalents in plasma, SH residue concentration, decreased in July compared with December (P < 0.05). Another antiradical molecule, ascorbic acid concentration in plasma, also decreased in July (P < 0.01). The oxidative stress index, thiobarbituric acid reactive substance (TBARS), which was produced from the oxidation of polyunsaturated fatty acids under oxidative conditions, increased in summer (P < 0.05). A significant positive relationship of SH residue and ascorbic acid concentrations in the hot season was observed (P < 0.01). A negative correlation between rectal temperatures and ascorbic acid concentrations in the hot season was obtained (P < 0.01). However, TBARS concentration varied independently of the SH residue and ascorbic acid concentration. These results suggest that the response of oxidative stress markers of SH residue, ascorbic acid and TBARS concentration to oxidative stress under hot conditions were not shown to be the same, and that oxidative stress in dairy cows in the hot season increased.
Temporal and spatial spread of Lettuce mosaic virus in lettuce crops in central Spain: factors involved in Lettuce mosaic virus epidemics
Authors: Moreno A. , Nebreda M. , Diaz B.M. , García M. , Salas F. , Fereres A.
Published: May 2007

Lettuce mosaic virus (LMV) is transmitted by aphid vectors in a nonpersistent manner as well as by seeds. The virus causes severe disease outbreaks in commercial lettuce crops in several regions of Spain. The temporal and spatial patterns of spread of LMV were studied in autumn 2002 in the central region of Spain. Symptomatic lettuce (var. Cazorla) plant samples were collected weekly, first at the seedling stage from the greenhouse nursery and later outdoors after transplantation. The exact position of symptomatic plants sampled in the field was recorded and then material was tested by enzyme‐linked immunosorbent assay to assess virus infection. Cumulative spatial data for infected plants at different growth stages were analysed using spatial analysis by distance indices. For temporal analysis, the monomolecular, Gompertz, logistic and exponential models were evaluated for goodness of fit to the entire set of disease progress data obtained. The results indicated that the disease progress curve of LMV epidemics in the selected area is best described by a Gompertz model and that the epidemic follows a polycyclic disease progression. Our data suggest that secondary cycle of spread occurs when noncolonising aphid species land on the primary infected plants (probably coming from infected seed) and move to adjacent plants before leaving the crop. The role of weeds growing close to lettuce fields as potential inoculum sources of virus and the aphid species most likely involved in the transmission of LMV were also identified.
Riqueza y Distribución Ecológica de Especies de Pteridofitas en la Zona del Río Yavarí‐Mirín, Amazonía Peruana
Authors: Cárdenas Glenda G. , Halme y Hanna Tuomisto Kati J.
Published: May 2007

We studied the ecological distribution of pteridophytes (ferns and fern allies) along eight 8‐km transects covering 12.7 ha in Peruvian Amazonia. Subunits of 200 m2 of the transects have previously been classified into four different forest types, and here we document and quantify the floristic differences among these forest types. Pteridophytes have been suggested as an indicator group to classify rain forest habitats, but this requires that the ecological preferences of the species are well documented and consistent across geographic regions. Here we analyzed in detail the distribution and diversity patterns of 130 species across the four rain forest types. Relative species abundance and species diversity were similar among some of the forest types and differed among others, but the species composition differed markedly. Our results largely confirmed the earlier interpretation of the edaphic preferences of the pteridophyte species in western Amazonia. This supports the proposition that deterministic processes have an important role in influencing the floristic composition of Amazonian forests.
Photosynthesis and Optimal Light Microhabitats for a Rare Cactus, Mammillaria gaumeri, in Two Tropical Ecosystems
Authors: Cervera J. Carlos , Andrade José Luis , Graham Eric A. , Durán Rafael , Jackson Paula C. , Simá J. Luis
Published: May 2007

Mammillaria gaumeri, an endemic cactus from Yucatan, is threatened due to human‐mediated habitat fragmentation but knowledge regarding factors that would inform management plans is limited, including information on optimal microhabitats and growth. We studied seasonal patterns of microclimate, net CO2 uptake and growth of adult individuals during the dry, rainy and northwind (late fall to winter) seasons in separate populations located in a coastal dune and in a dry forest. To provide an assay of primary productivity, we measured the production of new axillary buds (areoles) from the apex. We found that patterns of net CO2 uptake in the three seasons were consistent with obligate crassulacean acid metabolism. The reduction in soil water potential and the increase in water vapor pressure deficit led to a reduction in 24‐h net CO2 uptake from 18.0 to 1.3 mmol CO2/m2, after 30 d of drought. Dry‐weight gain was maximal during the rainy season and there was no growth during the dry season, thus seasonal patterns of net CO2 uptake and growth for M. gaumeri reflected soil and atmospheric water contents. Annual dry‐weight gain increased linearly with plant size and with total daily photosynthetic photon flux density (PPFD) up to 80 percent of ambient. Maximal growth was in exposed microhabitats receiving 60–80 percent of total ambient PPFD. We hypothesize that low‐magnitude disturbances, resulting in more exposed microhabitats, might be beneficial for growth and conservation of adult individuals of this rare species.
A Case Report of Plasmapheresis and Cyclophosphamide for Steroid‐Resistant Focal Segmental Glomerulosclerosis: Recovery of Renal Function After Five Months on Dialysis
Authors: Oliveira Lily , Wang Donald , McCormick Brendan B
Published: May 2007

Abstract:  We describe a patient who presented with nephrotic syndrome and progressive renal failure with biopsy findings of focal segmental glomerulosclerosis (FSGS). He progressed rapidly to end‐stage renal disease (ESRD) and remained hemodialysis dependent for five months despite high dose prednisone therapy. Initiation of plasmapheresis and low dose oral cyclophosphamide resulted in the prompt return of urine output and renal recovery. He remains off dialysis with stable renal function (creatinine clearance = 40 mL/min) two years later. This is the first report of late rescue from apparent ESRD due to FSGS with combined plasmapheresis and low dose oral cyclophosphamide.
Pharmaceuticals in On‐Site Sewage Effluent and Ground Water, Western Montana
Authors: Godfrey Emily , Woessner William W. , Benotti Mark J.
Published: May 2007

Human use of pharmaceuticals results in the excretion and disposal of compounds that become part of municipal and domestic waste streams. On‐site waste water disposal and leaking city sewer systems can provide avenues for the migration of effluent to the underlying aquifers. This research assessed the occurrence and persistence of 22 target pharmaceuticals in septic tank effluent and two shallow, coarse‐grained aquifers in western Montana. Twelve compounds (acetaminophen, caffeine, codeine, carbamazepine, cotinine, erythromycin‐18, nicotine, paraxanthine, ranitidine, sulfamethoxazole, trimethoprim, and warfarin) were detected in a high school septic tank effluent. Three of the 12 compounds, carbamazepine, sulfamethoxazole, and nicotine, were detected in the underlying sand and gravel aquifer after effluent percolation through a 2.0‐m thick sand vadose zone. Sampling of a second sand, gravel, and cobble dominated unconfined aquifer, partially overlain by septic systems and a city sewer system, revealed the presence of caffeine, carbamazepine, cotinine, nicotine, and trimethoprim. The presence of carbamazepine and sulfamethoxazole in these aquifers appears to correlate with local usage based on a reported monthly prescription volume. This work highlights the need for expanding geochemical investigations of sewage waste impacted ground water systems to include sampling for selected pharmaceuticals.
Update on the Use of the RORA Program for Recharge Estimation
Authors: Rutledge Albert T.
Published: May 2007

An update on the use of the RORA program is provided to supplement information given in the initial description of the program in Ground Water in 1994. The method estimates ground water recharge on the basis of streamflow records. Important considerations in the use of the automated approach are described that should improve the reliability of recharge estimates and avoid misapplication of the technique. Topics include the recession index, errors caused by direct surface runoff, the time scale for reporting results, comparisons with results of manual calculations, and errors caused by gradual recharge and discharge. The use of ground water levels for independent assessment of results from RORA is also described. RORA results are compared and contrasted with results from other base flow separation techniques.
Are Models Too Simple? Arguments for Increased Parameterization
Authors: Hunt Randall J. , Doherty John , Tonkin Matthew J.
Published: May 2007

The idea that models should be as simple as possible is often accepted without question. However, too much simplification and parsimony may degrade a model’s utility. Models are often constructed to make predictions; yet, they are commonly parameterized with a focus on calibration, regardless of whether (1) the calibration data can constrain simulated predictions or (2) the number and type of calibration parameters are commensurate with the hydraulic property details on which key predictions may depend. Parameterization estimated through the calibration process is commonly limited by the necessity that the number of calibration parameters be smaller than the number of observations. This limitation largely stems from historical restrictions in calibration and computing capability; we argue here that better methods and computing capabilities are now available and should become more widely used. To make this case, two approaches to model calibration are contrasted: (1) a traditional approach based on a small number of homogeneous parameter zones defined by the modeler a priori and (2) regularized inversion, which includes many more parameters than the traditional approach. We discuss some advantages of regularized inversion, focusing on the increased insight that can be gained from calibration data. We present these issues using reasoning that we believe has a common sense appeal to modelers; knowledge of mathematics is not required to follow our arguments. We present equations in an Appendix, however, to illustrate the fundamental differences between traditional model calibration and a regularized inversion approach.
Psychological Treatments That Cause Harm
Authors: Lilienfeld Scott O.
Published: May 2007

The phrase primum non nocere (“first, do no harm”) is a well-accepted credo of the medical and mental health professions. Although emerging data indicate that several psychological treatments may produce harm in significant numbers of individuals, psychologists have until recently paid little attention to the problem of hazardous treatments. I critically evaluate and update earlier conclusions regarding deterioration effects in psychotherapy, outline methodological obstacles standing in the way of identifying potentially harmful therapies (PHTs), provide a provisional list of PHTs, discuss the implications of PHTs for clinical science and practice, and delineate fruitful areas for further research on PHTs. A heightened emphasis on PHTs should narrow the scientist-practitioner gap and safeguard mental health consumers against harm. Moreover, the literature on PHTs may provide insight into underlying mechanisms of change that cut across many domains of psychotherapy. The field of psychology should prioritize its efforts toward identifying PHTs and place greater emphasis on potentially dangerous than on empirically supported therapies.
The Economics of Rising Fuel Costs and European Fisheries Les pêcheries européennes confrontées à la croissance du coût des carburants Die ökonomischen Aspekte steigender Mineralölkosten und europäischer Fischerei
Authors: Arnason Ragnar
Published: May 2007

summary

The Economics of European Fisheries

The huge increase in fuel prices — about doubling since 2004 — represents a major economic shock to European fishing fleets. Before this latest price hike, fuel accounted for 15 per cent of the operating costs of most fleet segments. Thus, in spite of various fuel saving measures, this fuel price increase has probably reduced the profitability of European fishing fleets by well over 5 per cent of revenues on average. What is perhaps less obvious is that the fuel price increase also serves to bring the industry more into line with the biological productivity of the fish stocks. Many European fisheries today are characterized by excessive fishing fleets and severely overexploited fish stocks. It is shown in this article that lower profitability in fishing serves to reduce this excessive fishing pressure leading to some fish stock recovery and the possibility of higher sustainable catches. Thus, as painful as it is to the fishing industry, this fuel price increase may actually contribute to a healthier fishery in the longer run, and by increasing sustainable catches also benefit consumers of fish. These benefits, however, will not materialize if the impact of the fuel price increase is neutralized by inadvisable financial subsidies to the fishing industry
Taxation of European Farmers La fiscalité des agriculteurs européens Die Besteuerung der Landwirte in Europa
Authors: Hill Berkeley , Cahill Carmel
Published: May 2007

summary

Taxation of European Farmers

The special treatments that farmers and landowners receive in national systems of taxation and social security are a little‐studied way in which governments are involved with agriculture and provide it with support. As policy instruments they can be an alternative to programmes that involve government expenditure. A recent OECD inventory covering taxes on income, property (annual, transfers and capital gains) and inputs (such as duty on fuel) has found that special treatments of agriculture are widespread in Europe, mostly in the form of concessions relative to the arrangements applied to other industries and occupations. They represent an accumulation of responses to particular problems, many of which have receded into history. But once in place special treatments are often difficult to remove. Agricultural concessions influence the pattern of production in the short‐term and the structure of the industry and its output in the longer term. The present inventory reveals inconsistency and contains conflicts with other policy aims. The lack of transparency and difficulty of establishing clearly what is a preferential treatment, together with important information gaps, suggests that further study and evaluation of tax concessions is required. Nevertheless, special treatment of agriculture is too important to be ignored.
Ethanol Transforms Agricultural Markets in the USA L'éthanol transforme les marchés agricoles aux Etats‐Unis Ethanol transformiert die Agrarmärkte in den USA
Authors: Westhoff Pat , Thompson Wyatt , Kruse John , Meyer Seth
Published: May 2007

summary

Ethanol Transforms Agricultural Markets in the USA

In the United States the volume of ethanol produced from maize is increasing at a very fast rate. The high crude oil prices explain some of this growth, but government policies have also been instrumental by fostering the growth of the US ethanol industry. Tax credits and import tariffs have encouraged investment by increasing ethanol producer returns, while at the same time environmental regulations and mandated levels of renewable fuel use have encouraged, if not required, gasoline blenders to use ethanol. The growing biofuel industry has resulted in closer links between energy and agricultural markets more than ever before. Prices for maize and other grains have increased, feed rations have changed, and the expected taxpayer cost of traditional US farm commodity programs has sharply declined. In 2006, high petroleum prices along with supportive policies contributed to record high US ethanol prices and massive investment in even greater production capacity. The immediate implications for the European Union are higher world commodity prices as maize is reallocated to ethanol production. As biofuels represent a larger share of motor fuel use in the US than in the EU, the US experience is a useful point of comparison as EU energy policies are developed.
Valuing Water Rights in Douglas County, Oregon, Using the Hedonic Price Method1
Authors: Butsic Van , Netusil Noelwah R.
Published: May 2007

Abstract:  This paper uses the hedonic price method to estimate the value of an acre‐foot of irrigation water in Douglas County, Oregon. The analysis uses detailed information from 113 arms‐length transactions of farmland for 2000 and 2001. The estimated willingness‐to‐accept of $261 to sell an acre‐foot of irrigation water is consistent with other studies and recent transactions in the study area. Estimates for the value of leasing water are provided using a range of discount rates and leasing periods.
Sensitivity Analysis of a FGR Industrial Furnace for NOx Emission Using Frequency Domain Method
Authors: Jiang Qing , Zhang Chao , Jiang Jin
Published: May 2007

Preliminary study has shown that the flue gas recirculation (FGR) is one of the effective ways to reduce the nitric oxides (NOx) emission in industrial furnaces. The sensitivity of the NOx emission from a FGR industrial furnace to the change in three major furnace input variables—inlet combustion air mass flow rate, inlet combustion air temperature, and pressure head of the FGR fan—is investigated numerically in this study. The investigation is carried out in frequency domain by superimposing sinusoidal signals of different frequencies on to the furnace control inputs around the design operating condition, and observing the frequency responses. The results obtained in this study can be used in the design of active combustion control systems to reduce NOx emission. The numerical simulation of the turbulent non-premixed combustion process in the furnace is conducted using a moment closure method with the assumed β probability density function for the mixture fraction. The combustion model is derived based on the assumption of instantaneous full chemical equilibrium. The discrete transfer radiation model is chosen as the radiation heat transfer model, and the weighted-sum-of-gray-gases model is used to calculate the absorption coefficient.
An Experimental Study of Artificially-Generated Turbulent Spots Under Strong Favorable Pressure Gradients and Freestream Turbulence
Authors: Yaras M. I.
Published: May 2007

This paper presents experimental results on the internal flow structure of turbulent spots, and examines the sensitivity of this structure to streamwise acceleration rate and freestream turbulence. Measurements were performed on a flat plate, with two levels of freestream acceleration rate and three levels of freestream turbulence. The turbulent spots were generated artificially at a fixed distance from the test-surface leading edge, and the development of the spot was documented through hotwire measurements at three streamwise locations. The measurements were performed at multiple spanwise locations to allow observation of the three-dimensional spatial structure of the turbulent spot and the temporal evolution of this structure. Analysis of the perturbation velocity and rms velocity fluctuations provides insight into the variations of the streaky streamwise-velocity structure within the turbulent spot, with a focus on the effects of freestream acceleration rate and turbulence level.
LES Simulation of Backflow Vortex Structure at the Inlet of an Inducer
Authors: Yamanishi Nobuhiro , Fukao Shinji , Qiao Xiangyu , Kato Chisachi , Tsujimoto Yoshinobu
Published: May 2007

Turbopump inducers often have swirling backflow under a wide range of flow rates because they are designed with a certain angle of attack even at the design point in order to attain high cavitation performance. When the flow rate is decreased, the backflow region extends upstream and may cause various problems by interacting with upstream elements. It is also known that the backflow vortex structure occurs in the shear layer between the main flow and the swirling backflow. Experimental studies on the backflow from an inducer have given us insight into the characteristics of backflow vortex structure, but the limited information has not lead to the complete understanding of the phenomena. Numerical studies based on Reynolds-averaged Navier-Stokes (RANS) computations usually deteriorate when the flow field of interest involves large-scale separations, as shown by a previous study by Tsujimoto et al. (2005). On the other hand, the numerical approach using the Large Eddy Simulation (LES) technique has the potential to predict unsteady flows and/or flow fields that include regions of large-scale separation much more accurately than RANS computations does in general. The present paper describes the application of the LES code developed by one of the authors (Kato) to further understand the backflow vortex structure at the inlet of an inducer. First, the internal flow of the inducer was simulated, as a way to evaluate the validity of the proposed method, under a wide range of inlet flow coefficients. The static pressure peformance and the length of the backflow region was compared with measured values, and good agreement was obtained. Second, using the validated LES code, the fundamental characteristics of the backflow vortex was investigated in detail. It was found that the backflow vortices are formed in a circumferentially twisted manner at the boundary between the swirling backflow and the straight inlet flow. Also, the backflow vortices rotate in the same direction as the inducer, but with half of the circumferential flow velocity in the backflow region. Another finding was that the backflow region expands toward the center of the flow field and the number of vortices decrease, as the flow coefficient decreases. To the best of our knowledge, this is the first computation of the backflow at the inducer inlet to achieve quantitative agreement with measured results, and give new findings to the complicated three-dimensional structure of the backflow, which was very limited under experimental studies.
A Quasi-Analytical Method for Fluid Flow in a Multi-Inlet Collection Manifold
Authors: Sparrow Ephraim M. , Tong Jimmy C. K. , Abraham John P.
Published: May 2007

This paper sets forth a fully validated quasianalytical method for determining the fluid flow in a multi-inlet collection manifold. The method is based on first principles, which are the conservation laws for mass and momentum. Although it is necessary to use numerical means to extract results from the model, the solution task is accomplished by the use of a spreadsheet, without the need for complex software or large computer assets. The validation of the method was achieved by comparing the key results with those from a numerically exact simulation. The comparison included both local results and global results. For the local results, the accuracy of the model was found to be in the 1% range, while the global results from the model were accurate to about 4%. The investigated manifold was a case study drawn from a problem involving thermal management of electronic equipment, in which an array of coldplates discharged spent air into the manifold. It was found, from both the quasianalytical method and the numerical simulation, that there is a variation in the per-coldplate flowrate due to axial pressure variations in the manifold. These pressure variations can be attributed to the streamwise acceleration of the manifold flow due to the accumulation of the flow entering the manifold from the coldplate array. The utility of the quasianalytical method was further demonstrated by applying it to a number of other cases. In particular, the method was used to design a manifold capable of producing a uniform mass flowrate through all of its ports.
Flow Downstream of a Cluster of Nine Jets
Authors: Boutazakhti M. , Sullivan P. E. , Thomson M. J. , Yimer I.
Published: May 2007

This work is an experimental investigation of the flow downstream of a low emission nozzle. The nozzle is a 3×3 square matrix of nine small swirling air jets, has a design swirl number of 0.8, and operates at a Reynolds number of 40,000. Particle image velocimetry (PIV) was used to map the velocity field under nonburning and atmospheric conditions for the first 18 jet diameters downstream of the nozzle exit plane. Seeding was liquid injected into the air stream and drops were sized to filter out those larger than 3×3pixels. The results showed that the cluster blends into a single jet-like flow 12 jet diameters downstream with the axial component of the velocity displaying self-similar properties. Lateral jet interaction slows the decay of the axial component of the velocity and jet expansion in the developed region while accelerating the decay of the radial component.
Automatic Differentiation of the General-Purpose Computational Fluid Dynamics Package FLUENT
Authors: Bischof Christian H. , Bücker H. Martin , Rasch Arno , Slusanschi Emil , Lang Bruno
Published: May 2007

Derivatives are a crucial ingredient to a broad variety of computational techniques in science and engineering. While numerical approaches for evaluating derivatives suffer from truncation error, automatic differentiation is accurate up to machine precision. The term automatic differentiation comprises a set of techniques for mechanically transforming a given computer program to another one capable of evaluating derivatives. A common misconception about automatic differentiation is that this technique only works on local pieces of fairly simple code. Here, it is shown that automatic differentiation is not only applicable to small academic codes, but scales to advanced industrial software packages. In particular, the general-purpose computational fluid dynamics software package FLUENT is transformed by automatic differentiation.
Near-Wall Turbulent Pressure Diffusion Modeling and Influence in Three-Dimensional Secondary Flows
Authors: Sauret E. , Vallet I.
Published: May 2007

The purpose of this paper is to develop a second-moment closure with a near-wall turbulent pressure diffusion model for three-dimensional complex flows, and to evaluate the influence of the turbulent diffusion term on the prediction of detached and secondary flows. A complete turbulent diffusion model including a near-wall turbulent pressure diffusion closure for the slow part was developed based on the tensorial form of Lumley and included in a re-calibrated wall-normal-free Reynolds-stress model developed by Gerolymos and Vallet. The proposed model was validated against several one-, two, and three-dimensional complex flows.
Central haemodynamics and peripheral muscle function during exercise in patients with chronic heart failure
Authors: Warburton Darren E.R. , Taylor Arlana , Bredin Shannon S.D. , Esch Ben T.A. , Scott Jessica M. , Haykowsky Mark J.
Published: May 2007

In this narrative review of the current literature, we examine the central and peripheral mechanisms responsible for the exercise intolerance of chronic heart failure and highlight briefly the benefits of exercise training in the treatment of this debilitating disorder. Specifically, we identify the common finding of reduced cardiac output reserve during exercise conditions leading to decreased exercise tolerance. We also reveal that the stroke volume response to exercise varies depending on the individual patient, the presence of mitral regurgitation, and the aetiology of heart failure. Chronic heart failure patients with left ventricular systolic dysfunction appear able to use the Frank–Starling mechanism to compensate (in part) for their decreased contractile reserve. Patients with left ventricular diastolic dysfunction have normal contractile function; however, they are unable to make use of the Frank–Starling mechanism during exercise conditions. We also reveal that pericardial constraint may limit diastolic filling and exercise capacity in patients with chronic heart failure. It appears that interventions that reduce pericardial constraint and mitral regurgitation enhance diastolic filling and increase exercise tolerance. A series of peripheral muscle changes also occur, including changes in muscle mass, cellular structure, energy metabolism, and blood flow. Each of these factors is associated with decreased exercise capacity and the symptoms of chronic heart failure. Exercise training has been shown to improve both central haemodynamics and peripheral muscle function leading to improvements in exercise capacity, functional status, and overall quality of life in patients with chronic heart failure.
Cardiovascular consequences of high-performance aircraft maneuvers: implications for effective countermeasures and laboratory-based simulations
Authors: Scott Jessica M. , Esch Ben T.A. , Goodman Len S. , Bredin Shannon S.D. , Haykowsky Mark J. , Warburton Darren E.R.
Published: May 2007

The gravitational stress encountered by pilots of high-performance aircraft can cause dramatic shifts in blood volume and circulatory pressure, thus placing the cardiovascular system under significant stress, sometimes resulting in loss of consciousness due to cerebral under-perfusion. Since pilots experience both increased and decreased gravitational stress in high-risk environments, it is important not only to examine the cardiovascular effects of altered gravitational exposure, but also to create effective countermeasures that will increase pilot safety. In this review, we discuss the cardiovascular consequences of rapid changes in gravitational forces. We also examine the effectiveness of the countermeasures that have been developed to combat gravity-induced loss of consciousness. Finally, we examine those current laboratory-based techniques that simulate hyper-gravity and the “push–pull effect,” making it possible to investigate the cardiovascular mechanisms responsible for maintaining cerebral perfusion and consciousness.
The evaluation of cardiac function across the health spectrum under diverse conditions of physiological stress: introduction
Authors: Warburton Darren E.R. , Haykowsky Mark J.
Published: May 2007

In this paper we introduce 3 papers resulting from a symposium evaluating cardiac function across the health spectrum under varied conditions of physiological stress. Esch et al. (Appl. Physiol. Nutr. Metab. 32: this issue) evaluate the potential role the pericardium plays on diastolic filling in endurance-trained athletes. These authors reveal how pericardial remodelling may explain (in part) why endurance athletes can achieve superior stroke volumes during exercise while also being increasingly susceptible to orthostatic intolerance. Warburton et al. (Appl. Physiol. Nutr. Metab. 32: this issue) review the central and peripheral mechanisms responsible for the exercise intolerance of chronic heart failure. They also reveal the important therapeutic effects of exercise rehabilitation for the treatment of heart failure. Scott et al. (Appl. Physiol. Nutr. Metab. 32: this issue) highlight the cardiovascular consequences of the gravitational stress placed upon pilots and the countermeasures commonly used. Collectively, these articles highlight the importance and difficulty of assessing cardiac function under varied conditions of physiological stress.
Acute exercise markedly increases blood oxidative stress in boys and girls
Authors: Nikolaidis Michalis G. , Kyparos Antonios , Hadziioannou Marina , Panou Neraida , Samaras Leonidas , Jamurtas Athanasios Z. , Kouretas Dimitris
Published: May 2007

This study investigated the effect of an acute swimming protocol on selected blood redox status indices in trained children. Eleven boys and 11 girls (aged 9–11 y) swam 12 bouts of 50 m at a pace corresponding to 70%–75% of the participant’s 50 m maximum velocity, with each bout separated by 1 min rest periods. At rest, no differences in any redox status marker between boys and girls were observed. As compared with the pre-exercise values, significant increases in thiobarbituric acid-reactive substances (TBARS), protein carbonyls, catalase activity, total antioxidant capacity (TAC), and oxidized glutathione (GSSG) concentration, as well as significant decreases in reduced glutathione (GSH) concentration and GSH:GSSG, were found post-exercise in both boys and girls. The magnitude of the exercise-induced alterations in the blood redox status based on the calculated effect sizes could be considered large for all parameters in both sexes (median effect size in absolute values was equal to 1.38). The main finding of the present study is that an acute swimming bout at 70%–75% maximum velocity resulted in blood oxidative stress in a similar manner in both trained young boys and girls.
Arterial stiffness following repeated Valsalva maneuvers and resistance exercise in young men
Authors: Heffernan Kevin S. , Jae Sae Young , Edwards David G. , Kelly Erin E. , Fernhall Bo
Published: May 2007

The purpose of this study was to compare arterial stiffness after a bout of resistance exercise (RE) and an experimental condition consisting of repeated Valsalva maneuvers (VMs). Fourteen male participants randomly completed a lower-body, unilateral RE bout and a VM bout designed to alter blood pressure (BP) in a similar pulsatile fashion. Pulse-wave velocity (PWV, measured in metres per second (m·s–1)) was used to measure central and peripheral arterial stiffness and was assessed before and 20 min after each perturbation. Beat-to-beat blood pressure (BP) was assessed during bouts using finger plethysmography. Change in systolic BP, diastolic BP, mean arterial pressure, and pulse pressure were similar during both bouts. Central PWV increased after repeated VMs (7.1 ± 0.3 m/s to 7.8 ± 0.3 m/s), but not after RE (7.2 ± 0.3 m/s to 7.2 ± 0.3 m/s) (interaction, p = 0.032). There was no change in peripheral PWV after VM (8.9 ± 0.3 m/s to 9.3 ± 0.3 m/s) or RE (8.5 ± 0.2 m/s to 8.4 ± 0.2 m/s). Arterial stiffness increased after repeated VM. Even though presented with a similar BP load, arterial stiffness did not increase after acute RE. These findings suggest a role for VM in acutely altering arterial properties.
Association of insulin sensitivity and muscle strength in overweight and obese sedentary postmenopausal women
Authors: Karelis Antony D. , Tousignant Benoit , Nantel Julie , Proteau-Labelle Majorique , Malita Florin M. , St-Pierre David H. , Brochu Martin , Doucet Eric , Rabasa-Lhoret Rémi
Published: May 2007

The objective of this study was to examine the relationship between insulin sensitivity and lower body muscle strength in overweight and obese sedentary postmenopausal women. The design of the study was cross-sectional. The study population consisted of 82 non-diabetic overweight and obese sedentary postmenopausal women (age: 58.2 ± 5.1 y; body mass index (BMI): 32.4 ± 4.6 kg·m–2). Subjects were classified by dividing the entire cohort into quartiles based on relative insulin sensitivity expressed per kilograms of lean body mass (LBM) (Q1, < 10.3, vs. Q2, 10.3–12.4, vs. Q3, 12.5–14.0, vs. Q4, >14.0 mg·min–1·kg LBM–1). We measured insulin sensitivity (using the hyperinsulinemic–euglycemic clamp technique), body composition (using dual-energy X-ray absorptiometry), visceral fat and muscle attenuation (using computed tomography), and a lower-body muscle strength index expressed as weight lifted in kilograms per kilogram of LBM (kg·kg LBM–1) (using weight-training equipment). A positive and significant relationship was observed between insulin sensitivity and the muscle strength index (r = 0.37; p < 0.001). Moreover, a moderate but significant correlation was observed between the muscle strength index and muscle attenuation (r = 0.22; p < 0.05). Finally, the muscle strength index was significantly higher in the Q4 group compared with the Q2 and Q1 groups, respectively (3.78 ± 1.13 vs. 2.99 ± 0.77 and 2.93 ± 0.91 kg·kg LBM–1; p < 0.05). Insulin sensitivity is positively associated with lower-body muscle strength in overweight and obese sedentary postmenopausal women.
STRONG REPRESENTATION OF A DISCRETE DECISION PROCESS BY POSITIVELY/NEGATIVELY BITONE SEQUENTIAL DECISION PROCESS
Authors: MARUYAMA YUKIHIRO
Published: May 2007

In this paper, we will introduce a new subclass of bitone sequential decision process (bsdp) and give a representation theorem for the subclass called positively/negatively bsdp, shortly, p/n bsdp, that is, necessary and sufficient condition for p/n bsdp to strongly represent a given discrete decision process (ddp).
IMPRECISE DEA — ENVELOPMENT AND MULTIPLIER MODEL APPROACHES
Authors: CHEN YAO
Published: May 2007

When multiple outputs and multiple inputs are imprecise data such as bounded data, ordinal data or ratio bound data, the standard linear data envelopment analysis (DEA) model becomes a nonlinear and is called imprecise DEA (IDEA) which can either be converted into a linear program by scale transformations and variable alternations, or solved using the standard DEA model by converting imprecise data into a set of exact data. The current paper investigates the working mechanism of IDEA and shows alternative ways to convert ordinal data into a set of exact data. It is shown that (i) the original IDEA — multiplier IDEA (MIDEA) which is developed from the multiplier DEA model presents the best efficiency scenario, and (ii) the primal IDEA (PIDEA) which is developed from the primal DEA model presents the worst efficiency scenario. The nonlinear PIDEA can also be easily executed by the standard linear DEA models based upon a set of derived exact data whereas it cannot be converted into a linear program via scale transformations and variable alternations.
SPIN CONSTRAINTS ON REGGE PREDICTIONS AND PERTURBATIVE EVOLUTION IN HIGH ENERGY COLLISIONS
Authors: BASS STEVEN D.
Published: May 2007

Two key issues in the application of perturbative QCD and Regge predictions to high energy processes are whether the hard and soft pomerons should be considered as two separate distinct exchanges and whether the Regge intercepts are Q2 independent or not. Models involving a distinct hard pomeron exchange predict much larger values for the LHC total cross-section. Here we argue that there is a polarized analogue of this issue in the isovector part of the spin structure function g1 and that the spin data appear to favour a distinct hard exchange.
EXOTIC MOLECULAR IONS (HeH)2+ AND ${\rm He}_2^{3+}$ IN A STRONG MAGNETIC FIELD: LOW-LYING STATES
Authors: TURBINER A. V. , LÓPEZ VIEYRA J. C.
Published: May 2007

The Coulombic systems (αpe) and (ααe), (αppe), (ααpe) and ( Li 3+ Li 3+e) placed in a magnetic field B ≳ 1011 G are studied. It is demonstrated a theoretical existence of the exotic ion ( He H )2+ for B ≳ 5 × 1012 G in parallel configuration (the magnetic field is directed along internuclear axis) as optimal as well as its excited states 1π, 1δ. As for the exotic ion [Formula: see text] it is shown that in spite of strong electrostatic repulsion of α-particles this ion can also exist for B ≳ 100 a.u. (= 2.35 × 1011 G ) in parallel configuration as optimal in the states 1σg (ground state), 1πu, 1δg. Upon appearance both ions are unstable towards dissociation with He + in the final state but with very large lifetime. However, at B ≳ 10000 a.u. , the ion ( He H )2+ becomes stable, while at B ≳ 1000 a.u. , the ion [Formula: see text] becomes stable. For both ions the vibrational and rotational energies are calculated. With a magnetic field growth, both exotic ions become more and more tightly bound and compact, their lowest rotational and vibrational energies grow drastically. At the edge of applicability of nonrelativistic approximation, B ~ 4.414 × 1013 G , there are indications that three more exotic linear ions ( H – He – H )3+, ( He – H – He )4+ and even [Formula: see text] in parallel configuration may also occur.
IR WAVELENGTH DEPENDENCE QUANTUM SIZE EFFECTS IN Nb/SiO2 QUANTUM WELLS
Authors: VILLAGÓMEZ R.
Published: May 2007

This letter deals with the experimental observation of oscillations in the infrared reflectance from Nb ultra-thin films deposited on α-type SiO 2 substrates. P-polarized reflectance (Rp) measurements are made using a tunable p-polarized CO 2 waveguide laser using wavelengths between 9.2 and 10.4 μm. Several Nb/SiO 2 quantum wells were specially made by the RF sputtering technique. Tailored thicknesses run between 5.5 and 55 Å. Because of the strong influence from the chosen substrate, IR reflectivity was fitted to the optical response of our metal-substrate system by using the three-oscillator model and numerical calculations on the basis of the local field calculation for a single metallic quantum well. Although quantum size effects are well studied in semiconductor compounds, there are only a few studies of this effect in metallic films where the present investigation has its most important contribution.