bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiply charged ions from iodine laser-produced plasma of medium- and high-Z targets
Authors: Krása J. , Láska L. , Mašek K. , Pfeifer M. , Králiková B. , Skála J. , Straka P. , Rohlena K. , Mróz W. , Woryna E. , Parys P. , Wołowski J. , Haseroth H. , Golubev A. A. , Sharkov B. Yu.
Published: October 2009

Maximum charge states of ions registered in the far expansion zone from laser-produced plasma of Al, Co, Ni, Cu, Ta, W, Pt, Au, Pb, and Bi are presented. The Thomson parabola spectrometer was used to display a general view of the ion species of an expanding plasma while detailed ion charge-energy spectra were determined by the cylindrical electrostatic ion energy analyzer. The current densities of highly charged ion groups above 20 mA/cm2 were measured by use of an ion collector at a distance of ∼1 m from the target. The photodissociation iodine laser system PERUN (λ = 1.315 μm, power density up to ∼1015 W cm−2) was employed as a driver.
Simulation of preheating effects in shock wave experiments
Authors: Honrubia J. J. , Dezulian R. , Batani D. , Bossi S. , Koenig M. , Benuzzi A. , Grandjouan N.
Published: October 2009

We have analyzed the shock wave propagation experiments performed at LULI and presented at ECLIM'94. The targets were aluminium foils with thickness from 5 to 25 μm. Simulations were performed with the SARA-1D multigroup radiation code. We have shown a small level of preheating caused by the absorption of X-rays with energies close to the K-edge of aluminum. Several sets of opacities were used in order to study this effect, including experimental values for cold aluminum. Simulations show a small level of visible emission induced by X-ray preheating before the arrival of the shock.
Two-centre bound states in hot dense plasmas
Authors: Gauthier P. , Sauvan P. , Angelo P. , Alexiou S. , Leboucher-Dalimier E. , Poquerusse A. , Calisti A. , Talin B.
Published: October 2009

A model for describing the transient molecular behavior in hot dense plasmas is presented and applied to the case of a transient F8+/F9+ molecular ion embedded in a dense (Ne ≈ 1023 cm−3) fluorine plasma. Electron screening effects on molecular energy levels and on dipolar matrix elements are investigated for specific plasma conditions. The accuracy of the calculations is tested comparing values of the polarization shift of the FLyβ line as calculated from the present model to the ones determined in the framework of the Ion Sphere Model (ISM).
Integrated numerical simulation of indirect laser-driven implosion for ICF
Authors: Ramirez J. , Ramis R. , Meyer-Ter-Vehn J.
Published: October 2009

A NIF-type hohlraum target (Lindl 1995; CEA 1995) is analyzed in an integrated calculation that uses last revision (4.2) of MULTI2D code (Ramis et al. 1992). The numerical simulation includes: Lagrangian mesh, tracking of laser beams, inverse bremsstrahlung absorption, 3D radiation transport, radiation-induced hydrodynamics of casing and window panes, and radiatively driven capsule implosion. Electron heat conduction (Spitzer with flux limiter), tabulated Equations of State (Sesame), and LTE opacities are also included. Detailed results on hydrodynamic evolution of the system, compression symmetry, and energy balance are also provided.
Interaction of high intensity picosecond laser pulses with large preformed plasmas
Authors: Riley D. , Smith R.A. , MacKinnon A. J. , Willi O. , Hutchinson M.H.R.
Published: October 2009

The interaction of short (1−2 ps) laser pulses with solid targets at irradiances of over 1016 Wcm−2, in the presence of a substantial prepulse has been investigated. High absorption of laser energy is found even at high angles of incidence, with evidence for a resonance absorption peak being found for S, P, and circular polarizations. It is considered that this may be a result of refraction and beam filamentation, which causes loss of distinct polarization. Measurements of hard X-ray emission (∼ 100 keV) confirm a resonance absorption type peak at 45−50°, again for all three cases. Typically, 5−15% of the incident light is back-reflected by stimulated Brillouin scatter, with spatially resolved spectra showing evidence of beam hot-spots at high intensity. The possibility that filamentation and refraction of the beam can explain the lack of polarization dependence in the absorption and hard X-ray emission data is discussed.
Monte–Carlo simulations of fusion kinetic processes used to evaluate diagnostic techniques for laser target plasma
Authors: Gus'kov S. Yu. , Il'in D. V. , Levkovsky A. A. , Rozanov V. B. , Sherman V. E. , Vygovsky O. B.
Published: October 2009

Review and systematization of our investigations in thermonuclear (TN) plasma particle diagnostic methods are presented. The proposed diagnostic schemes are based on direct numerical simulations of nuclear reaction products kinetics in a dense hot plasma with the following interpretation of the results by means of analytical scaling relations for charged particles energy loss in plasma with arbitrary degeneration of electron gas. The simulations of the kinetic equations system solution for TN particles is carried out by TERAcode based on Monte–Carlo method. The diagnostic schemes are presented in the form of families of isoline curves at the (ρR, T)-plane which are related to the constant values of measured spectrum characteristics. The searching plasma parameters ρR and temperature T are determined by points of interceptions of curves related to the distinct characteristics. The ranges of applicability of different methods of particle diagnostics are investigated in detail.
Areal density diagnostics using suprathermal fusion reaction for laser-imploded D-T pellets
Authors: Tabaru Y. , Nakao Y. , Nakashima H. , Kudo K.
Published: October 2009

Detecting highly energetic neutrons produced by suprathermal fusion reactions is expected as a useful method for the areal density diagnosis in future ICF experiments. This paper examines the possibility of ρR diagnosis using suprathermal fusions, on the basis of transport calculations for neutrons and charged particles. Not only neutron elastic scattering but also nuclear elastic scattering of α-particles are considered as the processes producing energetic recoil ions. Since the suprathermal fusion reaction is affected by the plasma temperature through the slowing-down process of energetic α-particles and recoil ions, the yield ratio of highly energetic neutrons emitted from suprathermal fusions to total ones depends considerably on tne temperature. An areal density diagnostic method based on neutron spectroscopy is proposed here that can eliminate the influence of the plasma temperature on the determination of the areal density. Moreover, on the basis of coupled transport/hydrodynamic calculation, we derive a more realistic energy spectrum of neutrons escaping from laser-imploded D-T pellet and examine the usefulness of the diagnosis method proposed in this paper. It is shown that the Method proposed here may be useful for the areal density diagnosis in the ignition-grade ICF Pellets.
Lithium beam generation and focusing with a radial diode on PBFAII
Authors: Johnson D. J. , Rosenthal S. E. , Coats R. S. , Desjarlais M. P. , Lockner T. R. , Mehlhorn T. A. , Pointon T. D. , Ruiz C. L. , Stygar W. A. , Slutz S. A. , Wenger D. F.
Published: October 2009

The performance of a 15-cm-radius applied-magnetic-field ion diode was investigated on the PBFA II accelerator at a power of 23 TW. The power coupling between the accelerator and diode was measured and compared with numerical simulations that show the effects of the electron flow in the MITL. The power coupled to the cathode of the diode was 18 MW. Measurements of the lithium beam generated from an electric-field-emission LiF anode showed a lithium beam power of 9 TW. The lithium beam was ballistically focused in a gas cell filled with 2 torr argon. The resultant focused power density was ∼1.8 TW/cm2 equivalent on a cylindrical target at the centerline of the diode. The focused power was limited by the 20- to 30-mR divergence of the beam caused by the LiF source used and by virtual cathode instabilities in the anode–cathode gap. The ion mode instability in the virtual cathode was studied extensively by measurement of waves in the ion emission pattern from the anode and of the E-P0 correlation between variations in the beam energy and transverse momentum. The instability Played a dominant role in the limitation of the focused lithium power.
Time-resolved X-ray spectroscopy of deeply buried tracer layers as a density and temperature diagnostic for the fast ignitor
Authors: Koch J. A. , Back C. A. , Brown C. , Estabrook K. , Hammel B. A. , Hatchett S. P. , Key M. H. , Kilkenny J. D. , Landen O. L. , Lee R. W. , Moody J. D. , Offenberger A. A. , Pennington D. , Perry M. D. , Tabak M. , Yanovsky V. , Wallace R. J. , Wharton K. B. , Wilks S. C.
Published: October 2009

The fast ignitor concept for inertial confinement fusion relies on the generation of hot electrons, produced by a short-pulse ultrahigh intensity laser, which propagate through high-density plasma to deposit their energy in the compressed fuel core and heat it to ignition. In preliminary experiments designed to investigate deep heating of high-density matter, we used a 20 joule, 0.5–30 ps laser to heat solid targets, and used emission spectroscopy to measure plasma temperatures and densities achieved at large depths (2–20 microns) away from the initial target surface. The targets consisted of an Al tracer layer buried within a massive CH slab; H-like and He-like line emission was then used to diagnose plasma conditions. We observe spectra from tracer layers buried up to 20 microns deep, measure emission durations of up to 200 ps, measure plasma temperatures up to Te=650 eV, and measure electron densities above 1023 cm−3. Analysis is in progress, but the data are in reasonable agreement with heating simulations when space-charge induced inhibition is included in hot-electron transport, and this supports the conclusion that the deep heating is initiated by hot electrons.
Friedman, Liberalism and the Meaning of Negative Freedom
Authors: Smith Vardaman R.
Published: October 2009

In the ‘Introduction’ to Capitalism and Freedom, Friedman's stated intentions are to: (i) establish the role of competitive capitalism as a system of economic freedom and a necessary condition for political freedom; (ii) indicate the proper role of government in a free society; and (iii) return the term ‘liberal’ ‘… to its original sense – as the doctrines pertaining to a free man’ (1962, p. 6). In fact, Friedman accomplishes none of these things. This essay has three distinct, though related, objectives: first, to compare Friedman's position with the liberal alternative; second, to show why Friedman's position is more properly regarded as libertarian than liberal; and third, to assess the quality of Friedman's argument in its own right. My purpose is to demonstrate that Friedman overlooks the important liberal insight that the unrestricted accumulation of private propety may limit rather than promote individual freedom. This omission is crucial. Not only does it divorce Friedman's conception from liberalism, it also vitiates his case for economic freedom as a necessary condition for political freedom.
On the Possibility of Rational Dilemmas: An Axiomatic Approach
Authors: Cubitt Robin P.
Published: October 2009

In this paper, I address two connected issues that arise when one considers a rational agent facing a decision problem. One is whether or not the agent may find that the dictates of rationality are such that they cannot all be followed. For example, one may ask whether or not the requirements on the agent's actions imposed by rationality can conflict in an irreconcilable way, making it impossible to satisfy all of them. Put differently, one may ask whether or not any apparent conflict of this type must in fact be capable of rational resolution. I shall say that an agent who is in a position in which the requirements of rationality cannot all be satisfied faces a feasibility dilemma, and I shall characterize certain conceptions of rationality that differ according to whether or not they admit such a possibility. A second issue concerns the number of options that may be deemed rational in a decision problem. Is rationality sufficiently determinate that it always dictates precisely one choice, or may there be more than one rationally permissible option? Is there anything about rationality itself that guarantees that any of the possible options could rationally be chosen? I shall call this issue – whether the concept of rationality itself places any limits on the number of options that may be deemed rational in a given problem – the numbers problem.
Keynes's Theory of Probability and Its Relevance to His Economics: Three Theses
Authors: Cottrell Allin
Published: October 2009

One calls a lot of things propositions. If one sees this, then one can discard the idea Russell and Frege had that logic is a science of certain objects – propositions, functions, the logical constants – and that logic is like a natural science such as zoology and talks about these objects as zoology talks of animals. Like a natural science, it could supposedly discover certain relations. For example, Keynes claimed to discover a probability relation which was like implication, yet not quite implication. But logic is a calculus, not a natural science, and in it one can make inventions but not discoveries.

Giving grounds, however, justifying the evidence, comes to an end; – but the end is not certain propositions' striking us immediately as true, i.e. it is not a kind ofseeingon our part; it is ouracting, which lies at the bottom of the language-game. (Wittgenstein, 1969, §204)
On the Foundations of Hysteresis in Economic Systems
Authors: Cross Rod
Published: October 2009

Hysteresis means literally “that which comes later,” being derived from the Greek verb ύστερέω. Thus, hysteresis effects, generally defined, are those that persist after the initial causes giving rise to the effects are removed.

During the course of the 1980s, it became increasingly fashionable to invoke hysteresis effects to explain economic phenomena. Two of the main areas of application were to unemployment and international trade. In the case of unemployment, distinctive features of labor markets, such as social norms that rule out wage-cutting in the face of rising unemployment, imply that “increases in unemployment have a direct impact on the ‘natural’ rate of unemployment” (Blanchard and Summers, 1988, p. 15). The implication for macroeconomic systems is that “temporary shocks can have a permanent effect on the level of employment” (Ibid., p. 307). In the case of international trade, hysteresis effects arise from the industrial economics of sunk costs: “the argument is that firms must incur sunk costs to enter new markets, and cannot recoup these costs if they exit.… thus foreign firms that entered the U.S. market when the dollar was high do not abandon their sunk cost investments when the dollar falls.” The implication for trade flows is “an effect which persists after the cause that brought it about has been removed” (Dixit, 1989, p. 205).
A Political and Economic Case for the Democratic Enterprise
Authors: Bowles Samuel , Gintis Herbert
Published: October 2009

We consider two reasons why firms should be owned and run democratically by their workers. The first concernsaccountability: Because the employment relationship involves the exercise of power, its governance should on democratic grounds be accountable to those most directly affected. The second concernsefficiency: The democratic firm uses a lower level of inputs per unit of output than the analogous capitalist firm.
Game Theory and the History of Ideas about Rationality: An Introductory Survey
Authors: Cudd Ann E.
Published: October 2009

Although it may seem from its formalism that game theory must have sprung from the mind of John von Neumann as a corollary of his work on computers or theoretical physics, it should come as no real surprise to philosophers that game theory is the articulation of a historically developing philosophical conception of rationality in thought and action. The history of ideas about rationality is deeply contradictory at many turns. While there are theories of rationality that claim it is fundamentally social and aims at understanding and molding all facets of human psychological life, game theory takes rationality to be essentially located in individuals and to concern only the means to achieve predetermined ends. Thus, there are some thinkers who have made important contributions to this history who do not appear in the story of game theory at all, among them, Plato, Kant, and Hegel. There is, however, a clear trail to follow linking theories of instrumental rationality from Aristotle to the nineteenth-century marginalist economists and ultimately to von Neumann and Morgenstern and contemporary game theorists, that historically grounds game theory as a model of rational interaction.
Effects of physical maltreatment on the development of peer relations
Authors: Dodge Kenneth A. , Pettit Gregory S. , Bates John E.
Published: October 2009

The effect of early physical maltreatment on the development of peer relationships was examined in a representative sample of 585 boys and girls. Subjects were assessed for physical maltreatment in the first 5 years of life and then followed for 5 consecutive years. The assessment was based on a clinical interview with parents. Twelve percent of the sample was identified as having experienced physical maltreatment. Peers, teachers, and mothers independently evaluated the maltreated group of children as being more disliked, less popular, and more socially withdrawn than the nonmaltreated group in every year of evaluation, with the magnitude of difference growing over time. These effects held even when family socioeconomic status was controlled. The findings were interpreted as being consistent with the hypothesis that early maltreatment disrupts attachment relationships with adult caregivers, and these disruptions then impair a child's ability to form effective peer relationships.
Winter release and management of reintroduced migratory Whooping Cranes Grus americana
Authors: URBANEK RICHARD P. , FONDOW LARA E. A. , ZIMORSKI SARA E. , WELLINGTON MARIANNE A. , NIPPER MARK A.
Published: October 2009

From 2001 to 2005, 71 costume-reared juvenile Whooping Cranes Grus americana were led by ultralight aircraft from Wisconsin to a winter release site on the west-central Gulf Coast of Florida. A strategy was developed and implemented to maximize first winter survival while preventing exposure to non-costumed humans and tame Sandhill Cranes, maximize social bonding between males and females, promote safe roosting and wild behaviour, and minimize harassment by Whooping Cranes from earlier releases. Methods were improved each year; these modifications included enlargement of an open-topped release pen, creation of an artificial roosting substrate, addition of a top-netted pen, and holding birds at a distant pen site until older birds had cleared the release area. These techniques resulted in high survival and successful adaptation to the wild after migration from the winter release site.
Video-monitoring helps to optimize the rescue of second-hatched chicks in the endangered Bearded VultureGypaetus barbatus
Authors: MARGALIDA ANTONI , GARCÍA DIEGO , HEREDIA RAFAEL , BERTRAN JOAN
Published: October 2009

From 2000–2008 we used transmitting video cameras to document the breeding biology of the endangered Bearded Vulture in the Pyrenees (NE Spain), focusing the study on sibling aggression. Our goals were to study the feasibility of rescuing second-hatched chicks for conservation purposes in this species that shows obligate brood reduction. The age at which the second chick died varied between 4 and 9 days (n= 5). Prey items delivered per hour were not related to the survival time of the second chick or the aggressiveness of the first-hatched chick towards their sibling. Although sibling aggression generally began on day 1 after hatching, in two nests supplemented with food, aggression was delayed until the second and third day after hatching and the second chick survived for nine days. Our results on the death of the second chick and the test involving the rescuing of a second-hatched chick aged five days, suggest that the recommended age for intervention should be between 3 and 6 days, with 4–5 days probably being the optimal age for the rescue.
Diet Determines Features of the Metabolic Syndrome in 6- to 14-Year-Old Children
Authors: Aeberli Isabelle , Spinas Giatgen A. , Lehmann Roger , l’Allemand Dagmar , Molinari Luciano , Zimmermann Michael B.
Published: October 2009

Background/Objectives: Insulin resistance (IR) and hypertension are common in overweight children, and the adipocyte-derived hormones resistin, adiponectin, and leptin may modulate IR and blood pressure (BP). Few data exist in children on dietary determinants of IR, BP, or leptin, and no data exist on dietary determinants of resistin and adiponectin. Therefore, the objective of this study was to investigate dietary determinants of IR, BP, resistin, adiponectin, and leptin concentrations, as well as the interrelationship among these variables, in normal and overweight children. Subjects/Methods: In 6- to 14-year-old Swiss children (n=79), nutritional intake was assessed using two 24-hour-recalls and a one-day dietary record. Body mass index (BMI), body fat percentage (BF%), waist/hip ratio (W/H ratio), BP, glucose, insulin, resistin, adiponectin, and leptin were determined. IR was calculated using the quantitative insulin sensitivity check index (QUICKI). Results: BMI, BF%, and W/H ratio were significant predictors of leptin and insulin, QUICKI, and systolic BP, but not resistin or adiponectin. Of the overweight and obese children, 40 % were diagnosed pre-hypertensive or hypertensive. Total energy, fat, saturated fat, and protein intakes were significant predictors of fasting insulin and QUICKI, and total fat, saturated fat, and monounsaturated fat intakes were significant predictors of systolic BP, independent of BMI standard deviation score (BMI-SDS) and age. There were no associations between these dietary factors and leptin, adiponectin, or resistin. Conclusion: In children, dietary macronutrient composition is a predictor of IR and systolic BP, but not resistin, adiponectin, or leptin concentrations. Resistin and adiponectin concentrations are not correlated with IR or BP in this age range.
Effects of 3-Week Consumption of Green Tea Extracts on Whole-Body Metabolism During Cycling Exercise in Endurance-Trained Men
Authors: Eichenberger Philipp , Colombani Paolo C. , Mettler Samuel
Published: October 2009

The consumption of green tea has been generally associated with beneficial effects on human whole-body metabolism and recent investigations with animals indicate favorable effects of green tea extracts (GTE) on energy metabolism during exercise and aerobic exercise performance. Therefore, the purpose of this study was to examine the effects of a three-week supplementation with GTE on human energy metabolism during submaximal cycling exercise. In a randomized, double-blind crossover setting, ten healthy endurance-trained men exercised for 2 hours at 50 % Wmaxbefore and after three weeks of placebo or GTE supplementation (GTE containing about 160 mg∙day-1total catechins, of which about 70 mg∙day-1was epigallocatechin-3-gallate). The GTE supplementation did not influence indices of fat and energy metabolism (fatty acids, 3-β-hydroxybutyrate, triacylglycerol, low-density-lipoprotein cholesterol, total cholesterol, lactate, glucose, oxygen uptake, respiratory exchange ratio, energy expenditure), inflammation processes (interleukin-6, C-reactive protein), and oxidative stress (thiobarbituric-acid reactive substances, oxidized low-density-lipoprotein cholesterol), but plasma creatine kinase concentration at rest and during exercise was significantly lower (p = 0.039) and high-density-lipoprotein cholesterol concentration at rest was significantly higher (p = 0.043) compared to placebo. In conclusion, these results suggest only slight effects on whole-body metabolism after supplementation with GTE.
Effect of Fenugreek Seeds on Blood Glucose and Lipid Profiles in Type 2 Diabetic Patients
Authors: Kassaian Nazila , Azadbakht Leila , Forghani Badrolmolook , Amini Masud
Published: October 2009

Background: Recently use of herbal medicines, have been considered as an alternative for therapeutic usage. So, this study was undertaken to evaluate the hypoglycemic and hypolipidemic effects of fenugreek seeds in type 2 diabetic patients. Methods: In a clinical trial study, 24 type 2 diabetic patients were placed on 10 grams/day powdered fenugreek seeds mixed with yoghurt or soaked in hot water for 8 weeks. Weight, FBS, HbA1C, total cholesterol, LDL, HDL and food record were measured before and after the study. The differences observed in food records, BMI and serum variables were analyzed using paired-t-test and t-student and P≤0.05 was considered as significant. Results: After exclusion of 6 cases for changing in medication or personal problems, the results of 18 patients (11consumed fenugreek in hot water and 7 in yoghurt)were studied. Findings showed that FBS, TG and VLDL-C decreased significantly (25 %, 30 % and 30.6 % respectively) after taking fenugreek seed soaked in hot water whereas there were no significantly changes in lab parameters in cases consumed it mixed with yoghurt. BMI, Energy, Carbohydrate, Protein and fat intake remained unchanged during study. Conclusion: This study shows that fenugreek seeds can be used as an adjuvant in the control of type 2 diabetes mellitus in the form of soaked in hot water.
Bitter Melon Protects Against Lipid Peroxidation Caused by Immobilization Stress in Albino Rats
Authors: Chaturvedi
Published: October 2009

In the present study, protective effects of bitter melon (Momordica charantia) extract on lipid peroxidation induced by immobilization stress in rats have been assessed. Graded doses of extract (50, 100, and 150 mg/kg body weight) were administered orally to rats subjected to immobilization stress for two hours for seven consecutive days. Stress was applied by keeping the rats in a cage where no movement was possible. After seven days, rats were killed by decapitation after ether anesthesia. Blood and liver were collected to measure thiobarbituric acid reactive substances, reduced glutathione, and catalase. In vitro effects of M. charantia extract on lipid peroxidation in liver homogenate of normal, control, and rats pretreated with extract were carried out against cumene hydroperoxide-induced lipid peroxidation. Results reveal that in vivo M. charantia inhibited stress-induced lipid peroxidation by increasing the levels of reduced glutathione and activities of catalase. These results were further supported by in vitro results. In vitro inhibition of lipid peroxidation was indicated by low levels of thiobarbituric acid in the liver homogenate from pretreated rats and normal rats when incubated with both cumene hydroperoxide and extract. Inhibition was also noted in the homogenate where the rats were pretreated but the mixture contained no extract. Thus this plant provides protection by strengthening the antioxidants like reduced glutathione and catalase. Inclusion of this plant in the daily diet would be beneficial.
Antioxidant Effect on Urinary Excretion of Malondialdehyde in Non-Athletes During Aerobic Training
Authors: Hadley  , Visser  , Vander Steen
Published: October 2009

Conditions in the body during aerobic exercise increase the level of lipid peroxidation (LP). LP is associated with elevated concentration of modified low-density lipoproteins that are implicated in development of cardiovascular disease. Supplementation with antioxidant vitamin E to athletes at 267 mg (400 IUs) or greater has been reported to reduce levels of LP associated with exercise. Little is currently known about the effects of modest supplementation of vitamin E on previously sedentary adults who initiate an aerobic fitness program. In the present study, sedentary subjects (n = 14) kept 24-hour diet records to establish antioxidant intake of vitamins E and C and collected 24-hour urine samples that were used to determine baseline urinary malondialdehyde (MDA) concentrations, one measure of in vivo LP. No significant differences were noted in the parameters between groups. Seven subjects were randomly selected and supplemented daily with 133 mg (200 IUs) of vitamin E. All subjects participated in moderate-intensity aerobic training for 8 weeks. Post-training, non-supplemented subjects excreted significantly more MDA (p&<0.05) and consumed significantly fewer antioxidants than the supplemented group. Vitamin E supplementation appears to suppress elevated LP associated with beginning an aerobic exercise regimen in previously sedentary subjects.
Social Comparisons and Evaluations of Justice
Authors: Riederer Bernhard , Mikula Gerold , Bodi Otto
Published: October 2009

This research investigates the causal directions of associations between justice evaluations and social comparisons, distinguishing between the outcome and the frequency of making comparisons. Structural equation modeling analyses examine cross-sectional and longitudinal associations between women’s justice evaluations of the division of family work and the outcomes and frequencies of comparing their own shares and their partner’s shares of work (N = 389). Results support the existence of causal effects of (1) perceived justice on the frequency and outcome of comparisons and (2) of the frequency of comparisons on perceived justice. No support was obtained for causal effects of comparison outcome on perceived justice. The latter result is attributed to the long time interval of 3 years between the two surveys.
Prejudiced Behavior Toward Lesbians and Gay Men
Authors: Hendren Amy , Blank Hartmut
Published: October 2009

Investigations of prejudice toward lesbians and gay men mostly rely on self-report questionnaires and rarely make use of indirect, behavioral measures. This field experiment investigated helping in an everyday face-to-face situation as an indicator of discrimination. Members of the public (N = 240) were approached by a person asking for 10 pence for a parking meter. The requestor wore either a neutral or a pro-gay T-shirt. Additional independent variables were the requestor’s and the target person’s gender. Results showed that a person perceived as being a lesbian or a gay man received much less help, especially from men, than the same person perceived as being heterosexual. Findings are discussed in comparison with earlier studies involving either behavioral or self-report measures.
Effective Darcy‐scale contact angles in porous media imbibing solutions of various surface tensions
Authors: Weisbrod Noam , McGinnis Thomas , Rockhold Mark L. , Niemet Michael R. , Selker John S.
Published: October 2009

Surface tensions of high‐salinity solutions are significantly different from those of pure water. Our objective was to develop and test a methodology to determine whether these surface tension effects predictably alter imbibition into dry and moist porous media. Static and dynamic experiments were performed using four grades of quartz sand to determine the effects of solution salinity on imbibition. Results were quantified as apparent contact angles between the sand and three solutions (pure water, 5 molal NaNO3, and n‐hexane). Contact angles determined using a static method in initially air dried sand ranged from 23° to 31°, with the same values found for both water and the NaNO3 solution. Effective contact angles determined for the air‐dried sand using a dynamic method based on a modified version of the Green and Ampt model were about twice those found using the static method, averaging 45° and 62° for water and the NaNO3 solution, respectively. In prewetted sands, the dynamic imbibition data yielded apparent contact angles of 2° and 21° for water and the NaNO3 solution, respectively, with the latter value comparing well to a predicted value of 25° for the NaNO3 solution solely on the basis of surface tension contrast. The results of this study indicate that on the Darcy scale, saline solutions appear to follow the relationship of nonzero contact angles with other miscible fluids of different surface tensions used to prewet the sand grains, in agreement with the macroscale infiltration results of Weisbrod et al. (2004).
Optimization of a similarity measure for estimating ungauged streamflow
Authors: Reichl J. P. C. , Western A. W. , McIntyre N. R. , Chiew F. H. S.
Published: October 2009

One approach to predicting streamflow in an ungauged catchment is to select an ensemble of hydrological models previously identified for similar gauged catchments, where the similarity is based on some combination of important physical catchment attributes. The focus of this paper is the identification of catchment attributes and optimization of a similarity measure to produce the best possible ungauged streamflow predictions given a data set and a conceptual model structure. As a case study, the SimHyd rainfall‐runoff model is applied to simulate monthly streamflow in 184 Australian catchments. Initial results show that none of 27 catchment attributes can be safely said to consistently give a better ensemble of models than random selection when used independently of other attributes. This is contrary to prior expectations and indicates the sparseness of information within our database of catchments, the importance in this case of prior knowledge for defining important attributes, and the potential importance of combining multiple attributes in order to usefully gauge similarity. Seven relatively independent attributes are then selected on the basis of prior knowledge. The weight with which each of these attributes contributes to the similarity measure is optimized to maximize streamflow prediction performance across a set of 95 catchments. The other 89 catchments are used to independently test the accuracy of streamflow predictions. Using the optimal set of weights led to marked improvement in the accuracy of predictions, showing that the method, while inferior to local calibration, is superior to alternative methods of model regionalization based on regression and spatial proximity. However, there is evidence of nonuniqueness in the optimal solution and the possibility that the attribute weights are somewhat dependent on the catchments used.
Common depth of slab‐mantle decoupling: Reconciling diversity and uniformity of subduction zones
Authors: Wada Ikuko , Wang Kelin
Published: October 2009

Processes in subduction zones such as slab and mantle‐wedge metamorphism, intraslab earthquakes, and arc volcanism vary systematically with the age‐dependent thermal state of the subducting slab. In contrast, the configuration of subduction zones is rather uniform in that the arc is typically situated where the slab is ∼100 km deep. Toward reconciling the diversity and uniformity, we developed numerical thermal models with a nonlinear mantle rheology for seventeen subduction zones, spanning a large range of slab age, descent rate, and geometry. Where there are adequate observations, such as in Cascadia, northeast Japan, and Kamchatka, we find that surface heat flows can be explained if the interface between the slab and the mantle wedge is decoupled to a depth of 70–80 km. Models with this common decoupling depth predict that the region of high mantle temperatures and optimal fluid supply from the dehydrating slab, both required for melt generation for arc volcanism, occurs where the slab is ∼100 km deep. These models also reproduce the variations of the metamorphic, seismic, and volcanic processes with the thermal state of the slab. The shallow decoupling results in a stagnant fore arc whose thermal regime is controlled mainly by the subducting slab. The deeper coupling leads to a sudden onset of mantle wedge flow that brings heat from greater depths and the back arc, and its thermal effect overshadows that of the slab in the arc region. Our results serve to recast the research of subduction zone geodynamics into a quest for understanding what controls the common depth of decoupling.
Reconciling the geophysical and geochemical mantles: Plume flows, heterogeneities, and disequilibrium
Authors: Davies Geoffrey F.
Published: October 2009

Geophysical evidence and numerical models of mantle stirring imply the source of mid‐ocean ridge basalts (MORBs) comprises most of the mantle, excepting only the D″ region and the “superpile” anomalies deep under Africa and the Pacific. Geophysical evidence is also strong that the mantle is heated substantially from within. Geochemical inferences of a strongly depleted MORB source are inconsistent with this picture because they would require the MORB source to be heated mainly from below and because they cannot accommodate all of the Earth's incompatible elements. Lacking any other large mantle reservoir, the MORB source is required to balance the global uranium budget, which implies a U concentration of about 10 ng/g, more than double recent estimates. The MORB source would then have been depleted only by a factor of two in highly incompatible elements, rather than four or more, relative to is primitive composition. Both geophysical and geochemical evidence support a heterogeneous, multicomponent MORB source. Surprisingly, former plume material may comprise 25% of the MORB source, and this alone could add 50–100% to previous inventories of incompatible elements. Previous geochemical estimates may also be less secure because of a continuing focus on the more common, more depleted MORBs, because of long chains of geochemical inference, and because of a reliance on peridotites that may not have equilibrated with the mean composition of the heterogeneous source. Mean compositions are of most geophysical relevance, rather than putative end‐member compositions, but mean compositions will be difficult to estimate accurately because more enriched components are less common and more variable. Nevertheless, a reconciliation of geochemical and geophysical inferences seems possible.
Potential for decadal predictability in the North Pacific region
Authors: Sugiura Nozomi , Awaji Toshiyuki , Masuda Shuhei , Toyoda Takahiro , Igarashi Hiromichi , Ishikawa Yoichi , Ishii Masayoshi , Kimoto Masahide
Published: October 2009

A Predictable Component Analysis (PrCA) has been applied to near‐term forecasts of ocean‐atmosphere natural variability within a global warming scenario. The most predictable pattern in the North Pacific region on decadal time scales for the period 1965–1999 is a clockwise movement of heat content anomalies, which is composed of the eastward propagation along the Kuroshio‐Oyashio extension (hereafter KOE) region and the subsequent southwestward propagation along the subduction pathway through the subtropical region. Our results also suggest the important role played by the westward traveling Rossby wave north of the KOE region in determining the phase change of the Pacific Decadal Oscillation (PDO) during this period. A comparative study with different initial conditions demonstrates the importance of proper thermal constraints on the ocean subsurface, in conjunction with the Rossby wave dynamics, for the initiation of predictable patterns in the heat content anomaly.
Statistical evaluation of characteristic earthquakes in the frequency‐magnitude distributions of Sumatra and other subduction zone regions
Authors: Naylor M. , Greenhough J. , McCloskey J. , Bell A.F. , Main I.G.
Published: October 2009

If subduction zone earthquakes conform to a characteristic model, in which persistent segments fail at predictable stress levels due to the steady accumulation of tectonic loading, historical seismicity may constrain the occurrence of future events. We test this model for earthquakes on the Sumatra‐Andaman megathrust and other subduction zones using frequency‐magnitude distributions. Using simulations, we show that Poisson confidence intervals correctly account for the counting errors of histogram data. These confidence intervals demonstrate that we cannot reject the Gutenberg‐Richter distribution in favor of a characteristic model in any of the real catalogues tested. A visual bias in power‐law count data at high magnitudes, combined with a sample bias for large earthquakes, is sufficient to explain candidate characteristic events. This result implies that historical earthquakes are likely poor models for future events and that Monte Carlo simulations will provide a better assessment of earthquake and associated hazards.
Modeling the relaxation of early VLF perturbations associated with transient luminous events
Authors: Haldoupis Christos , Mika Ágnes , Shalimov Sergey
Published: October 2009

Studies show that early VLF perturbations, characterized by abrupt signal onsets and long recoveries, occur often in relation with transient luminous events, especially sprites and sprite halos. Also, most of the early VLF events are attributed to forward scattering of subionospheric VLF transmissions incident upon horizontally elongated disturbances of elevated ionization in the upper D region. This concept is supported by the similarity of early VLF event recoveries to those of lightning‐induced electron precipitation events (LEPs), which are due to electron density enhancements in the upper D region caused by lightning and whistler‐induced precipitation of radiation belt electrons. Here, the simplified Glukhov‐Pasko‐Inan model, that has been developed for LEP investigations, is applied to simulate early VLF event recoveries observed simultaneously with sprite discharges in the D region. The present study shows that: (1) early VLF events with longer (shorter) recoveries are likely to come from higher altitudes of about 80–90 km (lower altitudes of about 70–80 km) and under conditions of lower (higher) electron density elevations relative to ambient values; (2) although negative ion and positive cluster ion production plays a role in electron density relaxation at lower heights, the electron–single ion dissociative recombination is likely the key process at upper D region heights that defines the relaxation of early VLF perturbations; and (3) tentative estimates of electron density increases responsible for early VLF events may reach values possibly higher than 104 electrons per cm3 in the upper D region ionosphere.
Composition and variation of noise recorded at the Yellowknife Seismic Array, 1991–2007
Authors: Koper Keith D. , de Foy Benjamin , Benz Harley
Published: October 2009

We analyze seismic noise recorded on the 18 short‐period, vertical component seismometers of the Yellowknife Seismic Array (YKA). YKA has an aperture of 23 km and is sited on cratonic lithosphere in an area with low cultural noise. These properties make it ideal for studying natural seismic noise at periods of 1–3 s. We calculated frequency‐wave number spectra in this band for over 6,000 time windows that were extracted once per day for 17 years (1991–2007). Slowness analysis reveals a rich variety of seismic phases originating from distinct source regions: Rg waves from the Great Slave Lake; Lg waves from the Atlantic, Pacific, and Arctic Oceans; and teleseismic P waves from the north Pacific and equatorial mid‐Atlantic regions. The surface wave energy is generated along coastlines, while the body wave energy is generated at least in part in deep‐water, pelagic regions. Surface waves tend to dominate at the longer periods and, just as in earthquake seismograms, Lg is the most prominent arrival. Although the periods we study are slightly shorter than the classic double‐frequency microseismic band of 4–10 s, the noise at YKA has clear seasonal behavior that is consistent with the ocean wave climate in the Northern Hemisphere. The temporal variation of most of the noise sources can be well fit using just two Fourier components: yearly and biyearly terms that combine to give a fast rise in microseismic power from mid‐June through mid‐October, followed by a gradual decline. The exception is the Rg energy from the Great Slave Lake, which shows a sharp drop in noise power over a 2‐week period in November as the lake freezes. The Lg noise from the east has a small but statistically significant positive slope, perhaps implying increased ocean wave activity in the North Atlantic over the last 17 years.
Remote sensing of ocean waves by along‐track interferometric synthetic aperture radar
Authors: Zhang Biao , Perrie Will , He Yijun
Published: October 2009

A new wave retrieval method for the Along‐Track Interferometric Synthetic Aperture Radar (AT‐InSAR) phase image is presented. The new algorithm, named parametric retrieval algorithm (PRA), uses the full nonlinear mapping relations. It differs from previous retrieval algorithms in that it does not require a priori information about the sea state or the wind vector from scatterometer data. Instead, it combines the observed AT‐InSAR phase spectrum and assumed wind vector to estimate the wind sea spectrum. The method has been validated using several C‐band and X‐band HH‐polarized AT‐InSAR observations collocated with spectral buoy measurements. In this paper, X‐band and C‐band HH‐polarized AT‐InSAR phase images of ocean waves are first used to study AT‐InSAR wave imaging fidelity. The resulting phase spectra are quantitatively compared with forward‐mapped in situ directional wave spectra collocated with the AT‐InSAR observations. Subsequently, we combine the parametric retrieval algorithm (PRA) with X‐band and C‐band HH‐polarized AT‐InSAR phase images to retrieve ocean wave spectra. The results show that the ocean wavelengths, wave directions, and significant wave heights estimated from the retrieved ocean wave spectra are in agreement with the buoy measurements.
Analysis of hydrographic and stable isotope data to determine water masses, circulation, and mixing in the eastern Great Australian Bight
Authors: Richardson Laura E. , Kyser T. Kurt , James Noel P. , Bone Yvonne
Published: October 2009

Hydrographic and stable isotope data from waters in the eastern Great Australian Bight (GAB) sampled during March–April 1998 indicate that both mixing and evaporative processes are important on the shelf. Five water masses are defined on the basis of their temperature, salinity, δ2H and δ18O values. Two of these are end‐members, the Flinders Current (FC) and the Great Australian Bight Plume (GABP), whereas the other three are a result of mixing between these two end‐members. Water mass distribution reflects an anticyclonic gyre in the eastern GAB. Cool and fresh water present at depth along the Eyre Peninsula is sourced from upwelling of Flinders Current water directly from the shelf break. This water is progressively heated, evaporated, and mixed with warmer and more saline shelf waters as it flows around the gyre. High temperatures, salinities, and δ2H values in surface waters in the central GAB suggest that the Great Australian Bight Plume has a greater spatial extent than previously recorded, also occurring along the shelf edge between 130°E and 133°E. A high temperature, high salinity, low δ2H water mass that is isotopically similar to the Flinders Current occurs in the west of the study area, indicating intrusion of Flinders Current water into the central GAB. Differences in isotopic compositions of off‐shelf water suggest that the Great Australian Bight Plume is flowing off the shelf and mixing with Flinders Current water at ∼132°E; however, this outflow does not generate an eastward flowing current during the period when samples were collected.