bluuebunny/crossref_metadata_2025 huggingface dataset:
Leptin, IL‐10 and Inflammatory Markers (TNF‐α, IL‐6 and IL‐8) in Pre‐Eclamptic, Normotensive Pregnant and Healthy Non‐Pregnant Women
Authors: Sharma Alpana , Satyam Abhigyan , Sharma Jai Bhagwan
Published: May 2007

Problem

Despite progress in immunobiology, pre‐eclampsia (PE) remains one of the most common reasons for women to die during pregnancy. The widespread pathophysiological mechanisms are endothelial dysfunction, oxidative stress and inflammation. The aim of this study was to assess the alteration in the levels of leptin, interleukin (IL)‐10 and inflammatory cytokines [tumour necrosis factor (TNF)‐α, IL‐6 & IL‐8] in pre‐eclamptic (severe and mild), healthy pregnant and non‐pregnant women and correlate these parameters with disease severity.

Method of study

The levels of leptin, IL‐10 and inflammatory cytokines were measured by high sensitivity enzyme‐linked immunoabsorbant assay. The study subjects were 54 pre‐eclamptic women (ten severe and 45 milder), compared by age matched 50 healthy pregnant and 27 non‐pregnant women. Kruskal–Wallis non‐parametric analyses of variance followed by Mann–Whitney U‐test were used for statistical analysis.

Results

The levels of leptin, TNF‐α, IL‐6 & IL‐8 in pre‐eclamptic subjects were increased significantly when compared with the healthy control pregnant and non‐pregnant (P < 0.000). The concentration of IL‐10 has shown different pattern as its level decreased significantly (0.001) in pre‐eclamptic women (overall) in comparison with control subjects (pregnant & non‐pregnant). A combination of 80% or higher sensitivity and specificity was seen in the parameters analysed, except IL‐8 and IL‐10.

Conclusion

Our findings suggest a relationship among TNF‐α, IL‐6, IL‐8, IL‐10 and leptin and indicate that altered levels of above markers in PE might be used as markers of pro‐inflammation/anti‐inflammation and endothelial dysfunction in pre‐eclamptic pregnancies. These results also advocate the abnormal leptin and cytokine responses in mother, which might be involved in the pathogenesis of PE.
Redirection of Cytokine Production By Lymphocytes From Women with Pre‐Term Delivery By Dydrogesterone
Authors: Raghupathy Raj , Al Mutawa Esraa , Makhseed Ma'asoumah , Al‐Azemi Majedah , Azizieh Fawaz
Published: May 2007

Problem

To study the ability of dydrogesterone to modulate the production of pro‐inflammatory and anti‐inflammatory cytokines by lymphocytes from women undergoing pre‐term delivery (PTD).

Method of study

Peripheral blood mononuclear cells (PBMC) from 18 subjects undergoing PTD were stimulated with the mitogen phytohemagglutinin in the presence and absence of progesterone and dydrogesterone. The levels of interferon (IFN)‐γ, tumor necrosis factor (TNF)‐α, interleukin (IL)‐4, and IL‐10 in culture supernatants were then estimated by enzyme‐linked immunoabsorbant assay. Cytokine production in the presence and absence of progesterone and dydrogesterone were compared.

Results

The exposure of PBMC to dydrogesterone resulted in a significant inhibition in the production of the pro‐inflammatory cytokines IFN‐γ and TNF‐α and a significant increase in the levels of the anti‐inflammatory cytokine IL‐4, resulting in a substantial shift in the ratio of Th1/Th2 cytokines.

Conclusion

Dydrogesterone induces a shift in cytokine bias, by inhibiting pro‐inflammatory cytokine production and increasing anti‐inflammatory cytokine production.
The Impact of Leukemia Inhibitory Factor in Uterine Flushing on the Reproductive Potential of Infertile Women – A Prospective Study
Authors: Mikolajczyk Mateusz , Wirstlein Przemyslaw , Skrzypczak Jana
Published: May 2007

Problem

To determine the value of leukemia inhibitory factor (LIF) assessment for predicting the reproductive outcome.

Method of study

Two phase study. Phase I: assessment of LIF in uterine flushing. Phase II: 1,5 years after examining the last patient, a questionnaire was sent to all participants of the phase I. Phase I: Uterine flushing and endometrial samples were collected during implantation window from infertile patients with stage I/II endometriosis (n = 14), patients with idiopathic infertility (n = 27), luteal phase deficiency (n = 13), and fertile control (n = 21). LIF was assessed in uterine flushings in all patients by ELISA. In endometrium, semiquantitative RT‐PCR was performed for LIF mRNA expression. Phase II: questionnaire has been sent to all infertile women taking part in the first phase of the experiment, regarding their reproductive outcome.

Results

65.4% patients who had returned the questionnaire did get pregnant. LIF concentration at a cut‐off point of 2.31 pg/ml had a 95.7% sensitivity and 81.8% specificity in predicting the reproductive outcome.

Conclusion

This prospective study for the first time in literature indicates that the LIF assessment can be used as a predictor of reproductive success.
Characterization and structural modeling of a new type of thermostable esterase from Thermotoga maritima
Authors: Levisson Mark , van der Oost John , Kengen Servé W. M.
Published: May 2007

A bioinformatic screening of the genome of the hyperthermophilic bacterium Thermotoga maritima for ester‐hydrolyzing enzymes revealed a protein with typical esterase motifs, though annotated as a hypothetical protein. To confirm its putative esterase function the gene (estD) was cloned, functionally expressed in Escherichia coli and purified to homogeneity. Recombinant EstD was found to exhibit significant esterase activity with a preference for short acyl chain esters (C4–C8). The monomeric enzyme has a molecular mass of 44.5 kDa and optimal activity around 95 °C and at pH 7. Its thermostability is relatively high with a half‐life of 1 h at 100 °C, but less stable compared to some other hyperthermophilic esterases. A structural model was constructed with the carboxylesterase Est30 from Geobacillus stearothermophilus as a template. The model covered most of the C‐terminal part of EstD. The structure showed an α/β‐hydrolase fold and indicated the presence of a typical catalytic triad consisting of a serine, aspartate and histidine, which was verified by site‐directed mutagenesis and inhibition studies. Phylogenetic analysis showed that EstD is only distantly related to other esterases. A comparison of the active site pentapeptide motifs revealed that EstD should be grouped into a new family of esterases (Family 10). EstD is the first characterized member of this family.
Biochemical characterization of the minimal polyketide synthase domains in the lovastatin nonaketide synthase LovB
Authors: Ma Suzanne M. , Tang Yi
Published: May 2007

The biosynthesis of lovastatin in Aspergillus terreus requires two megasynthases. The lovastatin nonaketide synthase, LovB, synthesizes the intermediate dihydromonacolin L using nine malonyl‐coenzyme A molecules, and is a reducing, iterative type I polyketide synthase. The iterative type I polyketide synthase is mechanistically different from bacterial type I polyketide synthases and animal fatty acid synthases. We have cloned the minimal polyketide synthase domains of LovB as standalone proteins and assayed their activities and substrate specificities. The didomain proteins ketosynthase‐malonyl‐coenzyme A:acyl carrier protein acyltransferase (KS‐MAT) and acyl carrier protein‐condensation (ACP‐CON) domain were expressed solubly in Escherichia coli. The monodomains MAT, ACP and CON were also obtained as soluble proteins. The MAT domain can be readily labeled by [1,2‐14C]malonyl‐coenzyme A and can transfer the acyl group to both the cognate LovB ACP and heterologous ACPs from bacterial type I and type II polyketide synthases. Using the LovB ACP‐CON didomain as an acyl acceptor, LovB MAT transferred malonyl and acetyl groups with kcat/Km values of 0.62 min−1·μm−1 and 0.032 min−1·μm−1, respectively. The LovB MAT domain was able to substitute the Streptomyces coelicolor FabD in supporting product turnover in a bacterial type II minimal polyketide synthase assay. The activity of the KS domain was assayed independently using a KS‐MAT (S656A) mutant in which the MAT domain was inactivated. The KS domain displayed no activity towards acetyl groups, but was able to recognize malonyl groups in the absence of cerulenin. The relevance of these finding to the priming mechanism of fungal polyketide synthase is discussed.
The importance of weather and agronomic factors for the overwinter survival of yellow rust (Puccinia striiformis) and subsequent disease risk in commercial wheat crops in England
Authors: Gladders P. , Langton S.D. , Barrie I.A. , Hardwick N.V. , Taylor M.C. , Paveley N.D.
Published: May 2007

Disease survey data from 4475 randomly selected crops of wheat from England and Wales during 1985–2000 showed that yellow rust was most prevalent in 1988, 1989, 1990, 1998 and 1999. Disease severity on the upper two leaves was low as >95% crops had received foliar fungicides. Factors affecting the presence or absence (incidence) of yellow rust were investigated using random effects logistic regression (general linear mixed model). This enabled crop management (risk) variables for individual crops to be combined with meteorological variables measured at the county level. Two models are presented that analysed the effect of host genotype on incidence either solely through yellow rust resistance rating (Model 1) or by including both resistance rating (fixed effect) and cultivar (fitted as a random term) (Model 2). In both models, the percentage of crops with yellow rust decreased with cultivar disease resistance ratings ≥3, the occurrence of severe frosts (<−5°C), use of systemic seed treatment and application of foliar fungicide sprays. There were no significant effects (P < 0.05) of timing of fungicide sprays, previous cropping or summer weather. The use of risk variables associated with overwintering survival may help adjust fungicide inputs to seasonal risk.
Germination ecology of invasive alien Anthemis cotula helps it synchronise its successful recruitment with favourable habitat conditions
Authors: Rashid I. , Reshi Z. , Allaie R. R. , Wafai B. A.
Published: May 2007

Anthemis cotula is a widespread invasive alien species in Kashmir Himalaya. Being a winter annual, the species reproduces entirely by achenes and synchrony between germination requirements of the species and the habitat conditions must be of critical importance in its invasiveness. To examine how the achenes of different ages respond to different environmental cues, two laboratory experiments were performed wherein effects of different nitrogen applications and growth hormones under continuous light and dark conditions were explored. Results show that the achenes are positively photoblastic and have requirement for after‐ripening. Nitrogen applied either as potassium nitrate or as thiourea significantly improved achene germination both under continuous light and dark conditions. Although kinetin (6‐furfurylaminopurine) did not influence achene germination, gibberellic acid (GA3) applied at 1.0 mM concentration had the most significant effect on the final percentage germination under both light and dark conditions. These results suggest that the achenes have an elaborate mechanism of sensing the habitat conditions that helps them to synchronise their germination with favourable environmental conditions – a strategy that aids the species in ensuring recruitment, survival and its spread in Kashmir Himalaya.
Nectar Production of Calliandra longipedicellata (Fabaceae: Mimosoideae), an Endemic Mexican Shrub with Multiple Potential Pollinators
Authors: Hernández‐Conrique David , Ornelas Juan Francisco , García‐Franco José G. , Vargas C. Fabián
Published: May 2007

The nectar resource environment across which nectarivores forage may be patchy and variable. To understand the sources and consequences of such a variation, nectar production was investigated in Calliandra longipedicellata. Nectar was measured once a month throughout a 3‐mo winter season in two successive years at three sites. We also conducted diurnal and nocturnal field observations to describe visitation rates of floral visitors, and a pollinator exclusion experiment to evaluate diurnal and nocturnal pollination at the three sites. In all populations, nectar secretion was primarily nocturnal, although flowers produced some nectar during the day. Sugar production per flower varied significantly at both the seasonal and population levels, although nectar production rates and a well‐defined afternoon to morning production pattern were consistent across months, populations, and years. Average nectar production rates were high compared to other Calliandra species, and to most hummingbird‐ or hawkmoth‐pollinated plants in the region. Flowers were regularly visited by hawkmoths, bats, hummingbirds and various diurnal insects, and all populations had similar rates of visitation. Nocturnal insects had the highest overall visitation rates (three times as high as those by diurnal insects). Fruit production varied among pollination treatments and populations, and significant differences were found in fruit production when flowers exposed to both diurnal and nocturnal visitation were compared to flowers exposed only to diurnal visitation. Our results and the bright‐red staminal filaments of C. longipedicellata indicate lack of specialization for particular pollinators.
Saproflorivory: A Diverse Insect Community in Fallen Flowers of Lecythidaceae in French Guiana
Authors: Feinstein Julie , Mori Scott , Berkov Amy
Published: May 2007

We investigated insects associated with flowerfalls from seven tree species belonging to the Brazil nut family (Lecythidaceae) in the lowland rain forest of French Guiana. Freshly fallen androecia were collected from the forest floor and incubated in rearing chambers. Over 1300 insects representing 21 families were collected from the caged flowers, including abundant Diptera and Coleoptera, five moth morphospecies and four species of lycaenid butterflies. These insects feed on androecia. We also documented the presence of predators and parasitoids, indicating an additional trophic level.
The Use of Seeds by a Twig‐Dwelling Ant on the Floor of a Tropical Rain Forest
Authors: Pizo Marco Aurélio
Published: May 2007

The role of Pheidole praeses, a twig‐nesting ant inhabiting the floor of the Brazilian Atlantic forest, as potential secondary seed disperser was investigated. A total of 901 seeds (20 morphospecies) were retrieved from 50 nests, most of them intact and able to germinate. Considering the abundance of Pheidole species and the evidence pointing to their potential as seed dispersers, these ants may be important determinants of the recruitment of small‐seeded plants in tropical forests.

Abstract in Portugese is available at http://www.blackwell‐synergy.com/loi/btp.
Impact of Coastal Land Reclamation on Ground Water Level and the Sea Water Interface
Authors: Guo Haipeng , Jiao Jiu Jimmy
Published: May 2007

Land reclamation in coastal areas may have a significant effect on local ground water systems. Steady‐state analytic solutions based on Dupuit and Ghyben‐Herzberg assumptions are derived to evaluate this effect. Two situations are considered, both with ground water flow resulting from precipitation recharge: the coastal aquifer of an extensive landmass and an island. The results show that after reclamation, the water table rises and the salt water‐fresh water interface moves seaward. The degree of these changes depends on the extent of reclamation and the hydraulic conductivity of the fill material. For the island situation, the reclamation displaces the ground water divide and changes the ground water conditions in the entire island. An unintended advantage of the reclamation is an increase of fresh ground water resource because the reclaimed land can be an additional aquifer and rain recharge takes place over a larger area.
Hydrologic Significance of Carbon Monoxide Concentrations in Ground Water
Authors: Chapelle Francis H. , Bradley Paul M.
Published: May 2007

Dissolved carbon monoxide (CO) is present in ground water produced from a variety of aquifer systems at concentrations ranging from 0.2 to 20 nanomoles per liter (0.0056 to 0.56 μg/L). In two shallow aquifers, one an unconsolidated coastal plain aquifer in Kings Bay, Georgia, and the other a fractured‐bedrock aquifer in West Trenton, New Jersey, long‐term monitoring showed that CO concentrations varied over time by as much as a factor of 10. Field and laboratory evidence suggests that the delivery of dissolved oxygen to the soil zone and underlying aquifers by periodic recharge events stimulates oxic metabolism and produces transiently high CO concentrations. In between recharge events, the aquifers become anoxic and more substrate limited, CO is consumed as a carbon source, and CO concentrations decrease. According to this model, CO concentrations provide a transient record of oxic metabolism affecting ground water systems after dissolved oxygen has been fully consumed. Because the delivery of oxygen affects the fate and transport of natural and anthropogenic contaminants in ground water, CO concentration changes may be useful for identifying predominantly anoxic ground water systems subject to periodic oxic or microaerophilic conditions.
Comparison of Flowpaths to a Well and Spring in a Karst Aquifer
Authors: Toran Laura , Herman Ellen K. , White William B.
Published: May 2007

The permeability of some karst aquifers consists of networks of poorly integrated conduits and dissolution‐widened fractures. The flow includes conduit flow, especially during storm recharge, but lacks the focused recharge into single master conduits that occurs in more highly developed karst systems. The proportions of conduit and dispersed flow are difficult to quantify in such systems. This study examines the flowpaths in a small karst watershed, based on comparing the physical and chemical response to storm flow at both a spring and a well. By conducting continuous monitoring at both locations, a better understanding of the flowpaths in a poorly integrated network was obtained. A more permeable flowpath to the spring leads to faster storm response and lower ion concentrations. The flowpath to and from the well is more complicated. The higher ion content and slower storm response suggest slower, more dispersed flowpaths. However, the well has greater variation in ion chemistry. Periodic recharge may dilute well concentrations due to faster (conduit or fracture) flowpaths. Although karst systems such as this are difficult to characterize, applying a variety of geochemical and physical monitoring techniques at multiple locations illustrates that the flowpaths can vary in both space and time.
Extinction Depth and Evapotranspiration from Ground Water under Selected Land Covers
Authors: Shah Nirjhar , Nachabe Mahmood , Ross Mark
Published: May 2007

In many landscapes, vegetation extracts water from both the unsaturated and the saturated zones. The partitioning of evapotranspiration (ET) into vadose zone evapotranspiration and ground water evapotranspiration (GWET) is complex because it depends on land cover and subsurface characteristics. Traditionally, the GWET fraction is assumed to decay with increasing depth to the water table (DTWT), attaining a value of 0 at what is termed the extinction depth. A simple assumption of linear decay with depth is often used but has never been rigorously examined using unsaturated‐saturated flow simulations. Furthermore, it is not well understood how to relate extinction depths to characteristics of land cover and soil texture. In this work, variable saturation flow theory is used to simulate GWET for three land covers and a range of soil properties under drying soil conditions. For a water table within half a meter of the land surface, nearly all ET is extracted from ground water due to the close hydraulic connection between the unsaturated and the saturated zones. For deep‐rooted vegetation, the decoupling of ground water and vadose zone was found to begin at water table depths between 30 and 100 cm, depending on the soil texture. The decline of ET with DTWT is better simulated by an exponential decay function than the commonly used linear decay. A comparison with field data is consistent with the findings of this study. Tables are provided to vary the extinction depth for heterogeneous landscapes with different vegetation cover and soil properties.
Using UCODE_2005 and PHREEQC To Determine Thermodynamic Constants from Experimental Data
Authors: Skold Magnus E. , Thyne Geoffrey D. , McCray John E.
Published: May 2007

This article presents a method for estimating chemical thermodynamic constants from experimental data using the two computer programs UCODE_2005 and PHREEQC. As an example, the conditional stability constant for lead (Pb) complexation by a remediation agent (carboxymethyl‐β‐cyclodextrin) is estimated, but the method can be applied to estimate other thermodynamic parameters such as sorption constants and degradation rate constants. Advantages of this technique include estimation of uncertainties associated with estimated parameters, evaluation of information content of observations, statistical evaluation of the appropriateness of the conceptual model, and statistical‐based comparison of different models.
Reply to Schooler: Consistent Is Not Conclusive
Authors: Salthouse Timothy A.
Published: May 2007

In this reply, I address the major issues raised by Schooler in his commentary on my article. Although we probably disagree about some points, I suspect that we are in agreement that there is empirical evidence that can be interpreted as being consistent with some aspects of the mental-exercise hypothesis. However, from my perspective, the available evidence is far from conclusive with respect to mental exercise slowing the rate of age-related mental decline, and recognition of the current state of uncertainty on this issue will likely facilitate progress in identifying the role of mental activity and other moderators of mental aging.
How Can Measures of Subjective Well-Being Be Used to Inform Public Policy?
Authors: Dolan Paul , White Mathew P.
Published: May 2007

The debate surrounding the use of subjective measures of well-being for policy purposes has intensified in recent years. Many social scientists are arguing that the time is right for policymakers to extend their traditional focus on material well-being and economic development to include the impact policies have on how people think and feel about their lives. However, policymakers may have many legitimate goals beyond making people happy. In this article, we begin by presenting three archetypal accounts of well-being that policymakers could use to guide policy (mental-state, objective-list, and desire-fulfillment accounts) and discussing some of the normative and methodological limitations of each. We discuss how a subjective (mental-state) approach could be used to aid the achievement of objective-list and desire-fulfillment policy goals. We then consider ways in which a subjective approach may benefit policymakers in its own right, such as by aiding the valuation of hard-to-quantify costs and benefits, providing a standard unit of measurement for comparisons of well-being across domains, and helping to set policy defaults. We conclude with a discussion of some of the remaining measurement issues and general policy implications.
Carbon Sequestration in Agriculture: EU and US Perspectives La séquestration du carbone en agriculture: perspectives pour l'Europe et les Etats Unis CO2‐Sequestrierung in der Landwirtschaft: Perspektiven für die EU und die USA
Authors: Young Linda M. , Weersink Alfons , Fulton Murray , Deaton B. James
Published: May 2007

summary

Carbon Sequestration in Agriculture: EU and US Perspectives

Both the European Union and the United States are defining the role that agricultural soil sequestration of carbon will play in their overall strategies to reduce greenhouse gas emissions. These decisions have important ramifications, as recent research indicates that soil sequestration of carbon may have the potential to reduce the need for reductions in greenhouse gas emissions. The EU ratified the Kyoto Protocol in 2002, but chose not to use soil sequestration of carbon in its strategy to address climate change, and has excluded it from the EU's new carbon market. The EU's strategy can be explained by uncertainties surrounding soil sequestration and by the importance of its international leadership on climate change. In contrast, the United States has not ratified the KP, but is encouraging the use of soil carbon sequestration on a modest level, through its agricultural policy and research. There is some trading taking place using soil sequestration in the weak US market for carbon, partially due to US freedom from international protocols on this method of greenhouse gas reduction. As both the science and international protocols for carbon sequestration advance, the EU may reconsider the use of agricultural sequestration of carbon as a means for achieving its Kyoto Protocol commitments.
Rural Development Group Politics: A Hidden Cost? Des coûts cachés dans l'économie politique des groupes de développement rural? Die Gruppenpolitik zur Entwicklung des ländlichen Raums: Versteckte Kosten?
Authors: McAreavey Ruth
Published: May 2007

summary

Rural Development Group Politics: A Hidden Cost?

I challenge the popular notion of European rural development group dynamics and argue for a better understanding of the role of micro‐politics as a means of enhancing the performance of these groups. The views are research based and have relevance to the broader rural development and regeneration sector. Micro‐politics involves knowledge, power, trust, perceptions, understanding, social networks, values and traits that arise as a result of individuals interacting within a group whilst working on a shared goal, such as rural development. The monetary and time costs to a community of failing to address micro‐politics and nurture positive group relations are considerable. These include time spent in unproductive meetings and poorly prioritized—and ultimately unsuccessful—funding applications as a result of failure to agree priorities. Successful groups rely on individuals interacting in a way that achieves a greater social good. Mutual trust amongst the actors lies at the heart of effective group activity. Effective management of micro‐politics requires steps to nurture a culture of mutual trust to ensure that rural development actors co‐operate rather than play destructive games with one another. A case study example of a relatively straightforward approach illustrates how this might be done in practice.
Non‐metallic grid for radiographic measurement
Authors: Krithika Arumbakkam C. , Kandaswamy Deivanayagam , Velmurugan Natanasabapathy , Krishna Velayudham Gopi
Published: May 2007

The purpose of this paper is to suggest an easier, non‐metallic radiographic grid system for measuring the working length and radiographic size of pathologic areas during endodontic diagnosis and prognosis determination.
Control of Vortex Shedding From a Bluff Body Using Imposed Magnetic Field
Authors: Singha Sintu , Sinhamahapatra K. P. , Mukherjea S. K.
Published: May 2007

The two-dimensional incompressible laminar viscous flow of a conducting fluid past a square cylinder placed centrally in a channel subjected to an imposed transverse magnetic field has been simulated to study the effect of a magnetic field on vortex shedding from a bluff body at different Reynolds numbers varying from 50 to 250. The present staggered grid finite difference simulation shows that for a steady flow the separated zone behind the cylinder is reduced as the magnetic field strength is increased. For flows in the periodic vortex shedding and unsteady wake regime an imposed transverse magnetic field is found to have a considerable effect on the flow characteristics with marginal increase in Strouhal number and a marked drop in the unsteady lift amplitude indicating a reduction in the strength of the shed vortices. It has further been observed, that it is possible to completely eliminate the periodic vortex shedding at the higher Reynolds numbers and to establish a steady flow if a sufficiently strong magnetic field is imposed. The necessary strength of the magnetic field, however, depends on the flow Reynolds number and increases with the increase in Reynolds number. This paper describes the algorithm in detail and presents important results that show the effect of the magnetic field on the separated wake and on the periodic vortex shedding process.
Development of a Nozzle-Flapper-Type Servo Valve Using a Slit Structure
Authors: Kawashima Kenji , Youn Chongho , Kagawa Toshiharu
Published: May 2007

Pneumatic servo valves play a significant role in power transmission and system control using a pressurized gas. When pressurized air passes through servo valves, noise and pressure fluctuations are often experienced at the downstream side, and such fluctuations limit the value’s efficiency. In this paper, a novel four-port nozzle-flapper-type servo valve using a slit structure instead of an orifice plate is proposed. The slit structure maintains a laminar flow condition, and this provides an opportunity for the minimization of the noise and pressure fluctuations. The slit structure is fabricated using etching technology. The flow characteristics of the slit are investigated theoretically and experimentally in order to evaluate the design specifications and characteristics of the valve. The experimental results indicated that the noise level decreased by approximately 15dB and could reduce the pressure fluctuation by 75%, compared with the previous valve. It is felt that the valve is more effective than many current valves.
Phase-Averaged PIV for the Nominal Wake of a Surface Ship in Regular Head Waves
Authors: Longo J. , Shao J. , Irvine M. , Stern F.
Published: May 2007

Phase-averaged organized oscillation velocities (U,V,W) and random fluctuation Reynolds stresses (uu¯,vv¯,ww¯,uv¯,uw¯) are presented for the nominal wake of a surface ship advancing in regular head (incident) waves, but restrained from body motions, i.e., the forward-speed diffraction problem. A 3.048×3.048×100m towing tank, plunger wave maker, and towed, 2D particle-image velocimetry (PIV) and servo mechanism wave-probe measurement systems are used. The geometry is DTMB model 5415 (L=3.048m, 1∕46.6 scale), which is an international benchmark for ship hydrodynamics. The conditions are Froude number Fr=0.28, wave steepness Ak=0.025, wavelength λ∕L=1.5, wave frequency f=0.584Hz, and encounter frequency fe=0.922Hz. Innovative data acquisition, reduction, and uncertainty analysis procedures are developed for the phase-averaged PIV. The unsteady nominal wake is explained by interactions between the hull boundary layer and axial vortices and incident wave. There are three primary wave-induced effects: pressure gradients 4%Uc, orbital velocity transport 15%Uc, and unsteady sonar dome lifting wake. In the outer region, the uniform flow, incident wave velocities are recovered within the experimental uncertainties. In the inner, viscous-flow region, the boundary layer undergoes significant time-varying upward contraction and downward expansion in phase with the incident wave crests and troughs, respectively. The zeroth harmonic exceeds the steady-flow amplitudes by 5–20% and 70% for the velocities and Reynolds stresses, respectively. The first-harmonic amplitudes are large and in phase with the incident wave in the bulge region (axial velocity), damped by the hull and boundary layer and mostly in phase with the incident wave (vertical velocity), and small except near the free surface-hull shoulder (transverse velocity). Reynolds stress amplitudes are an order-of-magnitude smaller than for the velocity components showing large values in the thin boundary layer and bulge regions and mostly in phase with the incident wave.
Large-Eddy Simulation With Simplified Collisional Microdynamics in a High Reynolds Number Particle-Laden Channel Flow
Authors: Chtab Anna , Gorokhovski Mikhael
Published: May 2007

Computing high Reynolds number channel flows laden by heavy solid particles requires excessive CPU resources to calculate interparticle collisions. Since the frequency of these collisions is high, the kinematic details of each elementary collision may not be essential when calculating particle statistics. In this paper, the dynamics of a particle with a phase trajectory that is discontinuous (due to collisions) is simulated using a hypothetical “noncolliding” particle moving along a trajectory smoothed over interparticle collisions. The statistical temperature of this particle is assumed to be in equilibrium with the statistical “temperature” of the resolved turbulence. This simplified microdynamic is introduced into ballistic calculations of particles within the framework of the “two-way” LES approach. The simulation was conducted specifically to compare the velocity statistics of the hypothetical particle with statistics yielded by measurements in the gas∕particle channel flow and by the LES∕particle approach where binary collisions were simulated. This paper shows that, by assuming the universality of collisional microdynamics, one may predict the experimental observation and the results of detailed simulations without requiring supplementary CPU resources to compute the binary collisions.
Conditionally-Sampled Turbulent and Nonturbulent Measurements of Entropy Generation Rate in the Transition Region of Boundary Layers
Authors: Walsh Edmond J. , Nolan Kevin P. , McEligot Donald M. , Volino Ralph J. , Bejan Adrian
Published: May 2007

Conditionally-sampled boundary layer data for an accelerating transitional boundary layer have been analyzed to calculate the entropy generation rate in the transition region. By weighing the nondimensional dissipation coefficient for the laminar-conditioned-data and turbulent-conditioned-data with the intermittency factor γ the average entropy generation rate in the transition region can be determined and hence be compared to the time averaged data and correlations for steady laminar and turbulent flows. It is demonstrated that this method provides, for the first time, an accurate and detailed picture of the entropy generation rate during transition. The data used in this paper have been taken from detailed boundary layer measurements available in the literature. This paper provides, using an intermittency weighted approach, a methodology for predicting entropy generation in a transitional boundary layer.
The unswallowed pill: physical activity
Authors: Imbeault Pascal
Published: May 2007

Sedentary lifestyle, excessive food intake, and consequent overweight and obesity markedly increase the risk of developing some cancers, type 2 diabetes, and cardiovascular disease. This paper briefly summarizes the beneficial impacts of physical activity in protecting against the development of these diseases.
Anti-oxidative systems in rat skeletal muscle after acute physical exercise
Authors: Bachur José Alexandre , Garcia Sérgio Britto , Vannucchi Hélio , Jordao Alceu Afonso , Chiarello Paula Garcia , Zucoloto Sérgio
Published: May 2007

The objective of this study was to analyze the oxidative stress of skeletal muscle of sedentary rats at the morphological and biochemical level, due to acute physical effort performed at different intensities and during different periods of time. Forty-two male sedentary Wistar rats were divided into two groups, group A (swimming for 50 min) and group B (swimming for 100 min), which were further subdivided into 3 different exercise intensities, non-weight bearing (subgroup I), 3% weight load (subgroup II), and 5% weighted load (subgroup III), as well as a control-rested group (C). The animals were killed by ether inhalation and fragments of the gastrocnemius muscle were removed for the determination of malondialdehyde (MDA), reduced glutathione (GSH), and vitamin E concentrations. When all groups were compared with the control-rested group (C), gastrocnemius MDA levels at 50 and 100 min were higher at all swimming intensities. GSH consumption was greater at all intensities in group A, and only at 100 min in group BI; vitamin E consumption was significantly higher only in groups BII and BIII. When groups were compared by intensity at each swimming time there were no differences between I, II, and III at 50 min for any of the substances analyzed (MDA, GSH, and vitamin E), but at 100 min opposite effects were observed for GSH and vitamin E, with vitamin E consumption and GSH recovery occurring with increasing weight load. Higher concentrations of skeletal muscle MDA could indicate elevated lipid peroxidation at each time and exercise intensity, with highest MDA levels observed after the longest exercise duration and at the highest intensity. The layer-line mode of utilization of body antioxidants could explain the concentrations of GSH and vitamin E: first the use of GSH, even with minor oxidative stress, and then vitamin E consumption only in the presence of greater and more prolonged oxidative stress, indicating the necessity of adequate body levels of both antioxidants for proper utilization by the body antioxidant defense system.
The potential role of the pericardium on diastolic filling in endurance-trained athletes under conditions of physiological stress
Authors: Esch Ben T.A. , Bredin Shannon S.D. , Haykowsky Mark J. , Scott Jessica M. , Warburton Darren E.R.
Published: May 2007

In this review, we examine the growing body of evidence suggesting that the pericardium plays an important role in modulating cardiac function during conditions of physiological stress. Specifically, we discuss the effects of the pericardium on left ventricular filling and compliance. Furthermore, we reveal that there is increasing evidence to support the contention that the pericardium is capable of adaptation in response to volume loading. We also provide data that suggests endurance-training is a good example of a physiological stressor capable of causing pericardial remodelling. These adaptations appear particularly beneficial during exercise and may explain (in part) the common finding of stroke volume increasing during exercise to a greater extent in endurance-trained athletes. However, this adaptation may also partially explain the increased susceptibility to orthostatic intolerance in endurance athletes.
Iron supplementation during pregnancy: what are the risks and benefits of current practices?
Authors: Rioux France M. , LeBlanc Caroline P.
Published: May 2007

Iron-deficiency anemia is still prevalent among pregnant women living in industrialized countries such as Canada. To prevent this deficiency, iron supplements (30 mg/d) are routinely prescribed to Canadian pregnant women. Recently, dietary reference intakes for iron have increased from 18 and 23 mg/d during the second and third trimesters, respectively, to 27 mg/d throughout the pregnancy for all age groups. Whether this new recommendation implies an increase of iron dosage in supplements has not been answered. Are there any benefits or risks for the mother and her infant associated with iron supplementation during pregnancy? If iron supplementation is recommended, what should be the ideal dosage? This article reviews current knowledge on the potential negative or positive impact of iron supplementation during pregnancy on the outcomes of both infants and mothers. Based on the literature reviewed, a low daily dose of iron (30 mg elemental iron) during pregnancy improves women’s iron status and seems to protect their infants from iron-deficiency anemia. Several studies have also shown that a low daily dose of iron may improve birth weight even in non-anemic pregnant women. However, higher dosages are not recommended because of the potential negative effects on mineral absorption, oxidative pathways, and adverse gastrointestinal symptoms. To date, it is still not clear if health professionals should recommend routine or selective supplementation. However, neither routine nor selective iron supplementation during pregnancy is able to eliminate iron-deficiency anemia. Even though the dietary reference intake for iron during pregnancy has been recently increased, we do not recommend higher doses of iron in supplements designed for pregnant women.
The spirit of sport, morality, and hypoxic tents: logic and authenticity
Authors: Malloy David Cruise , Kell Robert , Kelln Rod
Published: May 2007

The World Anti-Doping Agency (WADA) has recently made a decision to allow the use of hypoxic tents amid a significant amount of controversy over the morality of their use for athletic training purposes. Currently, altitude training is considered moral, but other means of improving aerobic performance are not; for example, blood doping. Altitude training and blood doping have similar results, but the methods by which the results are achieved differ greatly. The controversy lies in how the use of a hypoxic device falls within WADA’s philosophy, which will then dictate future policy. This paper discusses the influence of a hypoxic environment on human physiology, altitude training’s influence on athletic performance, the concept of authentic physiology, and moral behaviour that is the foundation for logical debate.
PIXE Analysis of Trace Heavy-Metals in River Waters Using an Ion-Exchange Cellulose Filter Paper
Authors: Yamazaki H. , Ishii K. , Amartaivan Ts. , Takahashi Y. , Matsuyama S. , Satoh T. , Sugihara S. , Orihara H. , Jon C. G.
Published: May 2007

A simple but precise method for the PIXE analysis of trace heavy-metals in aqueous samples was developed, in which the PIXE targets were prepared by pre-concentrating heavy metals on a cellulose phosphate ion-exchange filter paper and no additional chemical treatment was required. Heavy metals in trace concentrations were quantitatively retained up to 16.7 μ-equivalent on a sheet of filter paper due to the excellent selectivity for heavy metals and ion-exchange kinetics of phosphate groups in cellulose matrix. Heavy metals of less than 1 μg on one filter paper are precisely and rapidly determined by PIXE analysis using 3-MeV proton beams. The present method is compared with the method preparing a PIXE target for each dissolved species of an element contained in aqueous samples. It will be resulted that the newly developed method enables an on-line PIXE analysis for river waters.
APPLICATION OF PIXE TO CHARACTERIZATION OF SIZE-SEGREGATED SINGLE RAINDROPS
Authors: MA CHANG-JIN , KASAHARA MIKIO , TOHNO SUSUMU
Published: May 2007

The study of single raindrops is expected to give new and great information such as drop formation processes and pollutant scavenging mechanisms. To investigate the characteristics of individual raindrops, PIXE method was applied to elemental analysis. Size-segregated individual raindrops were collected at Kyoto University during rain event in October 2001. Detection limit of each element for polycarbonate filter used as the substrate of raindrops was calculated. The significant peaks of several elements in single raindrop corresponding to the channel number of PIXE could be resolved. Chlorine, potassium, and sulphur were found as major elements in each size raindrop. Strong raindrop size-dependence of every elemental concentration was shown. Chlorine, chromium, potassium, and calcium show the distinctively high scavenging rate at the beginning rainfall. They show 98 %, 97 %, 96 %, and 84 % scavenging rate, respectively and followed by iron and sulphur.
QUANTITATIVE ANALYSIS OF UNTREATED HUMAN NAILS FOR MONITORING HUMAN EXPOSURE TO HEAVY METALS
Authors: SERA K. , FUTATSUGAWA S. , MURAO S. , CLEMENTE E.
Published: May 2007

In order to address global environmental issues, a standard-free method developed by ourselves has been successfully applied to various kinds of bio-samples. Especially, a method for untreated hairs has been applied in many polluted areas to study human exposure to toxic elements. In addition to hair, nail is expected to give us valuable information about human exposure to toxic elements. However, the analysis requires relatively large amounts of samples and laborious sample preparation techniques which necessitate internal standards. In this work, we have developed a quantitative method for untreated human-nail analysis based on the standard-free method. It requires neither large amounts of nails nor complicated target preparation procedure. Furthermore, it is perfectly free from any ambiguity in target preparation such as volatilization of certain elements and contamination of the sample during chemical ashing. The optimum conditions of irradiating nail samples are established, and accuracy and reproducibility of the present method are confirmed. It is found that ultrasonic washing in distilled water is effective for many nail samples preventing the loss of elements from the sample. It is also found that elemental concentration in nails strongly depends on their sampling positions.
PIXE ELEMENTAL ANALYSIS OF DRINKING WATER SUPPLIES
Authors: Yamazaki H. , Ishii K. , Takahashi Y. , Amartaivan Ts. , Matsuyama S. , Satoh T. , Sugihara S. , Sera K. , JON G. C.
Published: May 2007

In this study, we carried out PIXE analysis of raw and treated water at five water treatment plants as well as of tap water from several houses located in each supply route. We used a simple fast procedure for preparing thin uniform targets of inorganic components in both soluble and insoluble fractions of aqueous samples in combination with preconcentration of trace heavy metals; that is, Nuclepore filtration targets for coarse particles, preconcentration targets for heavy metal ions and deposit targets for fine particles and soluble major constituents. The target preparation and the PIXE measurement are not time-consuming, and a broad range of concentrations (several tenths of ppb to a few tens of ppm) of 19 elements from Na to Pb is determined simultaneously with a precision sufficient to reveal the elemental distribution in the soluble and insoluble fractions. Tap water quality was examined as a function of elemental distribution in untreated water at the plants. We confirmed the increase of insoluble components of some heavy metals in untreated water taken from river due to heavy rainfall and the elution of Cu , Zn and Pb in drinking water by corrosion of the piping in some part of the water distribution systems.
APPLICATION OF MICRO-PIXE IN ATMOSPHERIC ENVIRONMENTAL SCIENCE RESEARCH: ELEMENTAL MAP OF LEAVES
Authors: SAITOH KATSUMI , IMASEKI HITOSHI , YUKAWA MASAE , NAGAFUCHI OSAMU
Published: May 2007

Micro-beam scanning PIXE and scanning transmission ion microscopy (STIM) were applied to measurement of Siebold's beech (Fagus crenata Blume) leaves. The beech leaf samples were collected from selected beech trees at Tsugaru Pass near the Shirakami-Sanchi World Heritage Area, in the 1999 growing season. We focused our interest on the influence of the atmospheric environment (acidic deposition, aerosol and gaseous substances, etc.) on the forest ecosystem. Our approach to real images of the deposition of airborne particulate on leaves led to the elucidation of the process of elemental absorption from air and plant metabolism. As a result, it is suggested that 1) overlapping STIM images and elemental maps demonstrate the patterns of the elemental absorption into plants, 2) comparison of the elemental maps of leaves taken at the different growth stages may provide useful clues to the elemental accumulation mechanism in leaves, and 3) silicon distribution in leaves is indicative of airborne particulate deposition on them.