bluuebunny/crossref_metadata_2025 huggingface dataset:
Poverty and the use of destructive fishing gear near east African marine protected areas
Authors: CINNER J. E.
Published: May 2010

Poverty may be an important influence on the exploitation of marine resources in tropical developing countries. A number of studies have hypothesized that destructive fishing gears, which can degrade habitat, capture high proportions of juvenile fish and ultimately lead to reduced yields, are primarily used by the poorer segments of society. However, few studies have empirically tested this relationship. This paper examines relationships between the use of destructive seine nets and thirteen socioeconomic conditions in communities adjacent to three peri-urban marine protected areas in east Africa. Fishers using destructive gears were younger, less likely to have capital invested in the fishery, had lower fortnightly expenditures and were poorer in two multivariate indices of material style of life. Based on the two multivariate material style of life indices, a binary logistic regression model classified whether fishers used destructive gears with almost 70% accuracy. These findings are broadly consistent with the literature on poverty traps, which are situations in which the poor are unable to mobilize the resources required to overcome low-income situations and consequently engage in behaviour that may reinforce their own poverty. Managers aiming to reduce destructive gear use may need to partner with civil society and donors to help break poverty traps.
Introduction
Authors: Mattern David B.
Published: May 2010

For a man who studied, but never practiced law, laws and lawgiving played a central role in the life of James Madison. In a public career spanning forty years, in which he served in the Virginia General Assembly, the Continental Congress, the Constitutional Convention, the United States Congress, as secretary of state, and as president, Madison could be found at the center of events, at one time or another, either establishing, expounding, discussing, interpreting, or executing state or federal law. Even in his long retirement, he had important things to say about constitutional interpretation. In all this activity, vital to the creation and continued well-being of the early Republic, did Madison's status as a law student, but not a lawyer, matter much in his search for solutions to the persistent problems of republican self-governance?
The Authority for Federalism: Madison's Negative and the Origins of Federal Ideology
Authors: LaCroix Alison L.
Published: May 2010

The Philadelphia convention of 1787 looms enormous in many accounts of U.S. constitutional history, serving as the set piece in which various and muddled worldviews, theories, interests, and allegiances gelled into a coherent science and structure of politics. The Convention thus becomes time zero in the chronology of U.S. political and constitutional development, a finite and forward-looking first moment defining, for good or ill, the terms according which subsequent debates regarding the nature of U S. government would be conducted.
A TEOTIHUACAN PRESENCE AT CHAC II, YUCATAN, MEXICO: Implications for early political economy of the Puuc region
Authors: Smyth Michael P. , Rogart Daniel
Published: May 2010

A long-term research program at the Maya center of Chac (II) is providing extraordinary new information regarding architecture, mortuary populations, and foreign presence at the Puuc hills during the Early Classic period (a.d.300–600). The finding of numerous early substructures at monumental and residential contexts, unusual mortuary practices, and various artifacts showing central Mexican inspiration and/or origin has led to the serious realization that the center of Chac did not develop in cultural isolation. It is becoming increasingly evident that Teotihuacan played a significant role, either directly or via one of its surrogates, in the rise of urban centers in the Puuc region. This paper explores the evidence of foreign influences and contacts at Chac and discusses the larger implications for the early political economy of the Puuc hills region and the region's relationship to greater Mesoamerica.
MODELS OF COSMIC ORDER: Physical expression of sacred space among the ancient Maya
Authors: Mathews Jennifer P. , Garber James F.
Published: May 2010

The archaeological record, as well as written texts, oral traditions, and iconographic representations, express the Maya perception of cosmic order, including the concepts of quadripartite division and layered cosmos. The ritual act of portioning and layering created spatial order and was used to organize everything from the heavens to the layout of altars. These acts were also metaphors for world creation, world order, and establishing the center as a position of power and authority. This article examines the articulations of these concepts from the level of caches to the level of regions from the past and present in an attempt to understand these ancient perceptions. We emphasize that basic organizational notions of the cosmos permeate all societal levels and argue that scholars should expand their focus to include how the sacred landscape and its related ideology were reproduced in the lives of everyday people.
RAGE and Aβ Immunoglobulins: Relation to Alzheimer’s disease-related cognitive function
Authors: MITCHELL MEGHAN B. , BUCCAFUSCO JERRY J. , SCHADE ROSANN F. , WEBSTER SCOTT J. , MRUTHINTI SHYAMALA , HARRELL DEAN U. , GULATI NIDHI K. , MILLER L. STEPHEN
Published: May 2010

The immunoglobulins (IgGs) for beta amyloid (Aβ) and receptors for the advanced glycation end products (RAGE) have previously been shown to be related to memory and language measures in a mixed neurological sample of older adults. In this study, we examined group differences in Aβ and RAGE IgGs, as well as the relationship between both IgGs and cognitive performance in nondiabetic older adults with normal cognition, mild cognitive impairment (MCI), and probable Alzheimer’s disease (AD). We found RAGE and Aβ levels to be elevated in some AD participants, leading to significant AD–control group differences. While there was an overall correlation between both IgG levels and global cognition across all three groups, this relationship was largely attributable to group differences in cognition, highlighted by considerable variability within groups in the relationship between IgG levels and cognition. While findings do not support a consistent relationship between cognition and either IgG, further research with larger samples is needed to better characterize cognitive differences between AD participants with highversuslow Aβ and RAGE titers. (JINS, 2010,16, 672–678.)
Prediction of driving ability with neuropsychological tests: Demographic adjustments diminish accuracy
Authors: BARRASH JOSEPH , STILLMAN ASHLEY , ANDERSON STEVEN W. , UC ERGUN Y. , DAWSON JEFFREY D. , RIZZO MATTHEW
Published: May 2010

Demographically adjusted norms generally enhance accuracy of inferences based on neuropsychological assessment. However, we hypothesized that demographic corrections diminish predictive accuracy for real-world activities with absolute cognitive demands. Driving ability was assessed with a 45-minute drive along a standardized on-road route in participants aged 65+ (24 healthy elderly, 26 probable Alzheimer’s disease, 33 Parkinson’s disease). Neuropsychological measures included: Trail-Making A and B, Complex Figure, Benton Visual Retention, and Block Design tests. A multiple regression model with raw neuropsychological scores was significantly predictive of driving errors (R2 = .199, p = .005); a model with demographically adjusted scores was not (R2 = .113, p = .107). Raw scores were more highly correlated with driving errors than were adjusted scores for each neuropsychological measure, and among healthy elderly and Parkinson’s patients. When predicting real-world activities that depend on absolute levels of cognitive abilities regardless of demographic considerations, predictive accuracy is diminished by demographic corrections. (JINS, 2010, 16, 679–686.)
The corpus callosum and empathy in adults with a history of preterm birth
Authors: LAWRENCE E.J. , ALLEN G.M. , WALSHE M. , ALLIN M. , MURRAY R. , RIFKIN L. , MCGUIRE P.K. , NOSARTI C.
Published: May 2010

Reduced posterior corpus callosum (CC) area has been consistently observed in children and adolescents born very preterm (VPT). CC structural differences are also observed in people diagnosed with empathy disorders. This study examined empathy in relation to CC size in VPT adults and controls. CC area was manually measured for 17 VPT adults and 9 controls. Participants completed the Interpersonal Reactivity Index (Davis, 1980) and the Empathy Quotient (Baron-Cohen & Wheelwright, 2004). VPT adults had reduced posterior CC area in contrast to controls, and a positive linear trend was observed between posterior CC size and gestational age. No between-group empathy differences were observed, although self-reported personal distress in response to social situations was higher in VPT adults, and negatively associated with anterior CC area. We conclude that VPT adults have a smaller posterior CC, which is associated with gestational age, and elevated social distress, which may be mediated by anterior CC size. (JINS, 2010, 16, 716–720.)
Nutritional intervention programme among a Japanese-Brazilian community: procedures and results according to gender
Authors: Damião Renata , Sartorelli Daniela Saes , Hirai Amélia , Massimino Flávia , Poletto Juliana , Bevilacqua Marselle Rodrigues , Chaim Rita , Antonio de Salvo Vera Lúcia Morais , Asakura Leiko , Ferreira Sandra Roberta Gouveia , Andreoni Solange , Gimeno Suely Godoy Agostinho
Published: May 2010

Objective

To describe the results of a nutritional intervention programme among Japanese-Brazilians according to gender.

Design

A non-controlled experimental study.

Setting

The research included three points of clinical, nutritional and physical activity evaluation: at baseline (in 2005), after the first year and at the end of the second year (in 2007). The paired Student t test and multiple linear regression analysis were used to evaluate changes in the subjects’ profile (clinical, nutritional and physical activity variables).

Subjects

Japanese-Brazilians (n 575) of both genders, aged over 30 years.

Results

We verified statistically significant reductions in body weight (0·9 kg), waist circumference (2·9 cm), blood pressure, fasting blood glucose (>3 mg/dl) and total cholesterol (>20 mg/dl) and its fractions, in both genders. We also found reductions in intake of energy (among men), protein (among women) and fat (both genders) and increases in intake of total fibre (among women) and carbohydrate (among men).

Conclusions

The intervention programme indicated meaningful benefits for the intervention subjects, with changes in their habits that led to a ‘healthier’ lifestyle positively impacting their nutritional and metabolic profile.
DETERMINISTIC AND STOCHASTIC MODELS FOR THE SPREAD OF CHOLERA
Authors: GANI J. , SWIFT R. J.
Published: May 2010

In this note, we study deterministic and stochastic models for the spread of cholera. The deterministic model for the total number of cholera cases fits the observed total number of cholera cases in some recent outbreaks. The stochastic model for the total number of cholera cases leads to a binomial type distribution with a mean that agrees with the deterministic model.
Can We Predict Risk-Taking Behavior?
Authors: Rubio Víctor J. , Hernández José M. , Zaldívar Flor , Márquez Oliva , Santacreu José
Published: May 2010

Objective behavioral personality measures are an alternative to traditional self-report personality assessment and overcome some of the difficulties traditional assessment has. This paper presents two studies to validate two measures of risk propensity. In Study 1, 1,325 applicants for an ab initio air-traffic control training program were assessed using the Roulette Test (RT) and the Crossing the Street Test (CtST). Convergent as well as criterion validity were tested using the guessing tendency demonstrated by participants in a multiple-choice test. Once the effect of general cognitive ability was leveled out, results showed the predictive capacity of both tests. Study 2 replicated the previous study: 127 3rd-year psychology students were assessed using the RT. Results showed that the test had an even higher predictive validity of the Guessing Tendency (GT) revealed in a multiple-choice test. The usefulness for personnel recruitment processes and other assessment contexts is emphasized as are future trends of objective personality assessment.
Measuring Social Anxiety in 11 Countries
Authors: Caballo Vicente E. , Salazar Isabel C. , Irurtia María Jesús , Arias Benito , Hofmann Stefan G.
Published: May 2010

This paper reports on two studies conducted to develop and validate a new self-report measure of social phobia/anxiety – the Social Anxiety Questionnaire for Adults (SAQ-A) (Cuestionario de ansiedad social para adultos, CASO-A). A diary-item recording procedure was used to generate the initial pool of items. In Study 1, data from 12,144 participants provided 6 factors with moderate intercorrelations. Estimates of internal consistency reliability were adequate (range = .86 to .92) for the 6 factors included in the final confirmatory factor analysis. In Study 2, data provided by 10,118 nonclinical participants were used to explore preliminary reliability and validity estimates for a revised version of the SAQ-A – the Social Anxiety Questionnaire for Adults Revised (SAQ-AR). Approximately 106 researchers from 10 Latin American countries and Spain contributed to this data collection process. Specific comments are made on the structure of the new questionnaire as regards some commonly-used self-report measures of social phobia/anxiety.
Equivalent Factorial Structure of the Brief Symptom Inventory (BSI) in Clinical and Nonclinical Jordanian Populations
Authors: Daoud Fawzi S. , Abojedi Amjed A.
Published: May 2010

This study investigates the equivalent factorial structure of the Brief Symptom Inventory (BSI) in clinical and nonclinical Jordanian populations, using both exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The 53-item checklist was administered to 647 nonclinical participants and 315 clinical participants. Eight factors emerged from the exploratory factor analysis (EFA) for the nonclinical sample, and six factors emerged for the clinical sample. When tested by parallel analysis (PA) and confirmatory factor analysis (CFA), the results reflected a unidimensional factorial structure in both samples. Furthermore, multigroup CFA showed invariance between clinical and nonclinical unidimensional models, which lends further support to the evidence of the unidimensionality of the BSI. The study suggests that the BSI is a potentially useful measure of general psychological distress in clinical and nonclinical population. Ideas for further research are recommended.
Upper crustal velocity structure beneath the central Lucky Strike Segment from seismic refraction measurements
Authors: Seher Tim , Singh Satish C. , Crawford Wayne C. , Escartín Javier
Published: May 2010

We present a three‐dimensional velocity model of the upper crust around the central volcano of the Lucky Strike Segment, Mid‐Atlantic Ridge. The model, constructed from a 3‐D array of air gun shots (37.5 m spacing along line and 100 m between lines) to ocean bottom seismometers fired during a 3‐D seismic reflection survey, shows an off‐axis velocity increase (∼1 km/s), a low‐velocity region within the median valley, and a low‐velocity anomaly underneath the Lucky Strike volcano. Our observations indicate a porosity decrease of 1%–9% (corresponding to a velocity increase of ∼0.5–1 km/s) over a distance of 8 km from the ridge axis (∼0.7 Ma) and a porosity decrease of 4%–11% (corresponding to a velocity increase of ∼2 km/s) between a depth of 0.5 and 1.75 km below seafloor. A sinusoidal variation in the traveltime residuals indicates the presence of azimuthal anisotropy with cracks aligned approximately along the ridge axis. We favor an interpretation in which upper crustal porosities are created by a combination of magmatic accretion (lava–sheeted dike boundary) and active extension (faults, fractures, and fissures). The porosity variation with depth probably depends on pore space collapse, hydrothermal alteration, and a change of stress accommodation. The off‐axis porosities are possibly influenced by both hydrothermal precipitation and the aging of the crust.
Hydrothermal circulation within the Endeavour Segment, Juan de Fuca Ridge
Authors: Johnson H. Paul , Tivey Maurice A. , Bjorklund Tor A. , Salmi Marie S.
Published: May 2010

Areas of the seafloor at mid‐ocean ridges where hydrothermal vents discharge are easily recognized by the dramatic biological, physical, and chemical processes that characterize such sites. Locations where seawater flows into the seafloor to recharge hydrothermal cells within the crustal reservoir are by contrast almost invisible but can be indirectly identified by a systematic grid of conductive heat flow measurements. An array of conductive heat flow stations in the Endeavour axial valley of the Juan de Fuca Ridge has identified recharge zones that appear to represent a nested system of fluid circulation paths. At the scale of an axial rift valley, conductive heat flow data indicate a general cross‐valley fluid flow, where seawater enters the shallow subsurface crustal reservoir at the eastern wall of the Endeavour axial valley and undergoes a kilometer of horizontal transit beneath the valley floor, finally exiting as warm hydrothermal fluid discharge on the western valley bounding wall. Recharge zones also have been identified as located within an annular ring of very cold seafloor around the large Main Endeavour Hydrothermal Field, with seawater inflow occurring within faults that surround the fluid discharge sites. These conductive heat flow data are consistent with previous models where high‐temperature fluid circulation cells beneath large hydrothermal vent fields may be composed of narrow vertical cylinders. Subsurface fluid circulation on the Endeavour Segment occurs at various crustal depths in three distinct modes: (1) general east to west flow across the entire valley floor, (2) in narrow cylinders that penetrate deeply to high‐temperature heat sources, and (3) supplying low‐temperature diffuse vents where seawater is entrained into the shallow uppermost crust by the adjacent high‐temperature cylindrical systems. The systematic array of conductive heat flow measurements over the axial valley floor averaged ∼150 mW/m2, suggesting that only about 3% of the total energy flux of ocean crustal formation is removed by conductive heat transfer, with the remainder being dissipated to overlying seawater by fluid advection.
Excitation of whistler mode chorus from global ring current simulations
Authors: Jordanova V. K. , Thorne R. M. , Li W. , Miyoshi Y.
Published: May 2010

We simulate ring current dynamics during the 22 April 2001 geomagnetic storm (Dstmin = −102 nT) using our global ring current–atmosphere interactions model (RAM) extended to relativistic energies and electrons. The model retains four dimensions by solving the bounce‐averaged kinetic equation as a function of radial distance in the equatorial plane, magnetic local time (MLT), energy, and pitch angle. RAM includes time‐dependent convective transport and radial diffusion, all major loss processes, and is coupled with a dynamic 2‐D plasmasphere model. The global electric fields, as well as the boundary conditions at geosynchronous orbit, are specified from the Rice Convection Model (RCM) driven by a plasma sheet source population that depends on interplanetary conditions. The 1–30 keV electron fluxes simulated with RAM during the main phase of the storm at 4 ≤ L ≤ 6.5 agree reasonably well with THEMIS statistical data for active times (AE* > 300 nT). We calculate the pitch angle anisotropy of ring current electrons and the linear growth rate of whistler mode chorus in the equatorial plane at L ≤ 6.5 and for all MLT. Intense chorus waves are generated outside the plasmasphere (L > 4) in the premidnight to dawn local time sector by ring current electrons with ∼5 keV resonant energy. The chorus intensification on the dayside is smaller, and it is caused by higher‐energy ∼10 keV electrons. We present first results of the path‐integrated amplification of chorus obtained with the HOTRAY code using RAM outputs at selected locations. Significant chorus amplification with wave gain G ≥ 200 dB is obtained near local midnight after the fresh injections of ring current electrons from the plasma sheet. The global distribution of enhanced chorus waves on the nightside shows good agreement with recent surveys of near‐equatorial plasma wave data from satellites.
A three‐dimensional dynamical model for channeled lava flow with nonlinear rheology
Authors: Filippucci Marilena , Tallarico Andrea , Dragoni Michele
Published: May 2010

Recent laboratory studies on the rheology of lava samples from different volcanic areas have highlighted that the apparent viscosity depends on a power of the strain rate. Several authors agree in attributing this dependence to the crystal content of the sample and to temperature. Starting from these results, in this paper we studied the effect of a power law rheology on a gravity‐driven lava flow. The equation of motion is nonlinear in the diffusion term, and an analytical solution does not seem to be possible. The finite‐volume method has been applied to solve numerically the equation governing the fully developed laminar flow of a power law non‐Newtonian fluid in an inclined rectangular channel. The convergence, the stability, and the order of approximation were tested for the Newtonian rheology case, comparing the numerical solution with the available analytical solution. Results indicate that the assumption on the rheology, whether linear or nonlinear, strongly affects the velocity and/or the thickness of the lava channel both for channels with fixed geometry and for channels with constant flow rate. Results on channels with fixed geometry are confirmed by some simulations for real lava channels. Finally, the study of the Reynolds number indicates that gravity‐driven lava channel flows are always in laminar regime, except for strongly nonlinear pseudoplastic fluids with low fluid consistency and at high slopes.
Ground surface deformation patterns, magma supply, and magma storage at Okmok volcano, Alaska, from InSAR analysis: 2. Coeruptive deflation, July–August 2008
Authors: Lu Zhong , Dzurisin Daniel
Published: May 2010

A hydrovolcanic eruption near Cone D on the floor of Okmok caldera, Alaska, began on 12 July 2008 and continued until late August 2008. The eruption was preceded by inflation of a magma reservoir located beneath the center of the caldera and ∼3 km below sea level (bsl), which began immediately after Okmok's previous eruption in 1997. In this paper we use data from several radar satellites and advanced interferometric synthetic aperture radar (InSAR) techniques to produce a suite of 2008 coeruption deformation maps. Most of the surface deformation that occurred during the eruption is explained by deflation of a Mogi‐type source located beneath the center of the caldera and 2–3 km bsl, i.e., essentially the same source that inflated prior to the eruption. During the eruption the reservoir deflated at a rate that decreased exponentially with time with a 1/e time constant of ∼13 days. We envision a sponge‐like network of interconnected fractures and melt bodies that in aggregate constitute a complex magma storage zone beneath Okmok caldera. The rate at which the reservoir deflates during an eruption may be controlled by the diminishing pressure difference between the reservoir and surface. A similar mechanism might explain the tendency for reservoir inflation to slow as an eruption approaches until the pressure difference between a deep magma production zone and the reservoir is great enough to drive an intrusion or eruption along the caldera ring‐fracture system.
Influence of the East Asian winter monsoon on the storm track activity over the North Pacific
Authors: Lee Yun‐Young , Lim Gyu‐Ho , Kug Jong‐Seong
Published: May 2010

We investigate the relationship between the East Asian winter monsoon (EAWM) and synoptic eddy activity over the North Pacific Ocean. It is well known that the subtropical Pacific jet becomes stronger during strong monsoon periods than during weak monsoons. The storm track is generally expected to be active when the EAWM is strong, owing to the enhanced subtropical jet. Contrary to this expectation, synoptic eddy activity is significantly reduced in strong EAWM years and, conversely, significantly increased during weak years. In addition, we found that EAWM‐induced lower level cooling brings about the reverse relationship: a stronger jet but with weaker storm activities. It is suggested that the local baroclinicity induced by the EAWM modulates the variation of both the jet and North Pacific storm track simultaneously in the interannual time scale. Because major lower level cooling is located in the western parts of both the subtropical jet and the storm track in longitudes and between the two central axes in latitudes, it induces the opposite sign of anomalous local baroclinicity at the two active regions and causes this reverse relationship. The wave seeding from East Asia to the North Pacific storm track is weakened owing to the anomalous lower level cooling in the northwestern Pacific, which also results in reduction of eddy generation and storm track activities.
Modeling global secondary organic aerosol formation and processing with the volatility basis set: Implications for anthropogenic secondary organic aerosol
Authors: Farina Salvatore C. , Adams Peter J. , Pandis Spyros N.
Published: May 2010

The volatility basis set, a computationally efficient framework for the description of organic aerosol partitioning and chemical aging, is implemented in the Goddard Institute for Space Studies General Circulation Model II′ for a coupled global circulation and chemical transport model to simulate secondary organic aerosol (SOA) formation. The latest smog chamber information about the yields of anthropogenic and biogenic precursors is incorporated in the model. SOA formation from monoterpenes, sesquiterpenes, isoprene, and anthropogenic precursors is estimated as 17.2, 3.9, 6.5, and 1.6 Tg yr−1, respectively. Reducing water solubility of secondary organic gas from 105 to 103 mol L−1 atm−1 (1 atm = 1.01325 × 105 N m−2) leads to a 90% increase in SOA production and an increase of over 340% in total atmospheric burden, from 0.54 to 2.4 Tg. Increasing the temperature sensitivity of SOA leads to a 30% increase in production, to 38.2 Tg yr−1. Since the additional SOA is formed at high altitude, where deposition time scales are longer, the average lifetime is doubled from 6.8 to 14.3 days, resulting in a near tripling of atmospheric burden to 1.5 Tg. Chemical aging of anthropogenic SOA by gas‐phase reaction of the SOA components with the hydroxyl radical adds an additional 2.7–9.3 Tg yr−1 of anthropogenic SOA to the above production rates and nearly doubles annual average total SOA burdens. The possibility of such high anthropogenic SOA production rates challenges the assumption that anthropogenic volatile organic compounds are not important SOA precursors on a global scale. Model predictions with and without SOA aging are compared with data from two surface observation networks: the Interagency Monitoring of Protected Visual Environments for the United States and the European Monitoring and Evaluation Programme.
On the complex conductivity signatures of calcite precipitation
Authors: Wu Yuxin , Hubbard Susan , Williams Kenneth Hurst , Ajo‐Franklin Jonathan
Published: May 2010

Calcite is a mineral phase that frequently precipitates during subsurface remediation or geotechnical engineering processes. This precipitation can lead to changes in the overall behavior of the system, such as flow alternation and soil strengthening. Because induced calcite precipitation is typically quite variable in space and time, monitoring its distribution in the subsurface is a challenge. In this research, we conducted a laboratory column experiment to investigate the potential of complex conductivity as a mean to remotely monitor calcite precipitation. Calcite precipitation was induced in a glass bead (3 mm) packed column through abiotic mixing of CaCl2 and Na2CO3 solutions. The experiment continued for 12 days with a constant precipitation rate of ∼0.6 milimole/d. Visual observations and scanning electron microscopy imaging revealed two distinct phases of precipitation: an earlier phase dominated by well distributed, discrete precipitates and a later phase characterized by localized precipitate aggregation and associated pore clogging. Complex conductivity measurements exhibited polarization signals that were characteristic of both phases of calcite precipitation, with the precipitation volume and crystal size controlling the overall polarization magnitude and relaxation time constant. We attribute the observed responses to polarization at the electrical double layer surrounding calcite crystals. Our experiment illustrates the potential of electrical methods for characterizing the distribution and aggregation state of nonconductive minerals like calcite. Advancing our ability to quantify geochemical transformations using such noninvasive methods is expected to facilitate our understanding of complex processes associated with natural subsurface systems as well as processes induced through engineered treatments (such as environmental remediation and carbon sequestration).
Persistence of heat waves and its link to soil moisture memory
Authors: Lorenz Ruth , Jaeger Eric B. , Seneviratne Sonia I.
Published: May 2010

In this study, we assess the role of soil moisture for heat wave persistence using simulations with a regional climate model. Several studies have investigated changes in the frequency of hot summer days but very few investigated changes in their persistence. We use two different heat wave thresholds, either defined by the 90th percentile of the control run or by the 90th percentile of the respective sensitivity experiment. We identify that simulations in which soil moisture is fixed to a constant value or prescribed seasonal cycle, even with prescribed constant dry conditions, present a lower intrinsic heat wave persistence than simulations with interactive soil moisture. This effect is related to the impact of soil moisture persistence in the interactive simulations and amounts to ca. 5–10% of the spell lengths of the 10% hottest days in the respective simulations. Our results highlight the key role of soil moisture memory for the persistence of heat wave events, beside the known effect of soil moisture on heat wave intensity.
Constraining climate sensitivity with linear fits to outgoing radiation
Authors: Murphy Daniel M.
Published: May 2010

Several papers have used correlations between outgoing radiation and surface temperature to estimate climate sensitivity via a linearized energy balance equation. A crucial assumption in such studies is the use of global averages to relate radiation and temperature data that are actually functions of space and time. Here it is shown that this assumption is important to understanding why transient and equilibrium climate feedbacks may differ. There are important limitations to derivations of climate sensitivity from correlations between radiation and temperature data. In particular, because of heat transport between regions, obtaining the equilibrium temperature change by multiplying the forcing by a climate sensitivity is valid only for a global domain. The analysis of Lindzen and Choi (2009) erroneously applies global concepts to a limited region. I also show that a simple, point‐by‐point regression of outgoing radiation against surface temperature gives better slope estimates than the interval method used by Lindzen and Choi (2009).
Significance of non‐sinking particulate organic carbon and dark CO2 fixation to heterotrophic carbon demand in the mesopelagic northeast Atlantic
Authors: Baltar Federico , Arístegui Javier , Sintes Eva , Gasol Josep M. , Reinthaler Thomas , Herndl Gerhard J.
Published: May 2010

It is generally assumed that sinking particulate organic carbon (POC) constitutes the main source of organic carbon supply to the deep ocean's food webs. However, a major discrepancy between the rates of sinking POC supply (collected with sediment traps) and the prokaryotic organic carbon demand (the total amount of carbon required to sustain the heterotrophic metabolism of the prokaryotes; i.e., production plus respiration, PCD) of deep‐water communities has been consistently reported for the dark realm of the global ocean. While the amount of sinking POC flux declines exponentially with depth, the concentration of suspended, buoyant non‐sinking POC (nsPOC; obtained with oceanographic bottles) exhibits only small variations with depth in the (sub)tropical Northeast Atlantic. Based on available data for the North Atlantic we show here that the sinking POC flux would contribute only 4–12% of the PCD in the mesopelagic realm (depending on the primary production rate in surface waters). The amount of nsPOC potentially available to heterotrophic prokaryotes in the mesopelagic realm can be partly replenished by dark dissolved inorganic carbon fixation contributing between 12% to 72% to the PCD daily. Taken together, there is evidence that the mesopelagic microheterotrophic biota is more dependent on the nsPOC pool than on the sinking POC supply. Hence, the enigmatic major mismatch between the organic carbon demand of the deep‐water heterotrophic microbiota and the POC supply rates might be substantially smaller by including the potentially available nsPOC and its autochthonous production in oceanic carbon cycling models.
Reproducibility of Striatal and Thalamic Dopamine D2 Receptor Binding Using [11C]raclopride with High-Resolution Positron Emission Tomography
Authors: Alakurtti Kati , Aalto Sargo , Johansson Jarkko J , Någren Kjell , Tuokkola Terhi , Oikonen Vesa , Laine Matti , Rinne Juha O
Published: May 2010

Positron emission tomography (PET) imaging of small striatal brain structures such as the ventral striatum (VST) has been hampered by low spatial resolution causing partial-volume effects. The high-resolution research tomograph (HRRT) is a brain-dedicated PET scanner that has considerably better spatial resolution than its predecessors. However, its superior spatial resolution is associated with a lower signal-to-noise ratio. We evaluated the test–retest reliability of the striatal and thalamic dopamine D2 receptor binding using the HRRT scanner. Seven healthy male volunteers underwent two [11C]raclopride PET scans with a 2.5-hour interval. Dopamine D2 receptor availability was quantified as binding potential (BPND) using the simplified reference tissue model. To evaluate the reproducibility of repeated BPND estimations, absolute variability (VAR) and intraclass correlation coefficients (ICCs) were calculated. VAR values indicated fairly good reproducibility and were 3.6% to 4.5% for the caudate nucleus and putamen and 4.5% to 6.4% for the lateral and medial part of the thalamus. In the VST, the VAR value was 5.8% when the definition was made in the coronal plane. However, the ICC values were only moderate, in the range of 0.34 to 0.66, for all regions except the putamen (0.87). Experimental signal processing methods improved neither ICC nor VAR values significantly.
An extracellular transglutaminase is required for apple pollen tube growth
Authors: Di Sandro Alessia , Del Duca Stefano , Verderio Elisabetta , Hargreaves Alan J. , Scarpellini Alessandra , Cai Giampiero , Cresti Mauro , Faleri Claudia , Iorio Rosa Anna , Hirose Shigehisa , Furutani Yutaka , Coutts Ian G. C. , Griffin Martin , Bonner Philip L. R. , Serafini-Fracassini Donatella
Published: May 2010

An extracellular form of the calcium-dependent protein-cross-linking enzyme TGase (transglutaminase) was demonstrated to be involved in the apical growth of Malus domestica pollen tube. Apple pollen TGase and its substrates were co-localized within aggregates on the pollen tube surface, as determined by indirect immunofluorescence staining and the in situ cross-linking of fluorescently labelled substrates. TGase-specific inhibitors and an anti-TGase monoclonal antibody blocked pollen tube growth, whereas incorporation of a recombinant fluorescent mammalian TGase substrate (histidine-tagged green fluorescent protein: His6–Xpr–GFP) into the growing tube wall enhanced tube length and germination, consistent with a role of TGase as a modulator of cell wall building and strengthening. The secreted pollen TGase catalysed the cross-linking of both PAs (polyamines) into proteins (released by the pollen tube) and His6-Xpr-GFP into endogenous or exogenously added substrates. A similar distribution of TGase activity was observed in planta on pollen tubes germinating inside the style, consistent with a possible additional role for TGase in the interaction between the pollen tube and the style during fertilization.
Bow shocks in ablated plasma streams for nested wire array z-pinches: A laboratory astrophysics testbed for radiatively cooled shocks
Authors: Ampleford D. J. , Jennings C. A. , Hall G. N. , Lebedev S. V. , Bland S. N. , Bott S. C. , Suzuki-Vidal F. , Palmer J. B. A. , Chittenden J. P. , Cuneo M. E. , Frank A. , Blackman E. G. , Ciardi A.
Published: May 2010

Astrophysical observations have demonstrated many examples of bow shocks, for example, the head of protostellar jets or supernova remnants passing through the interstellar medium or between discrete clumps in jets. For such systems where supersonic and super-Alfvénic flows and radiative cooling are all important, carefully scaled laboratory experiments can add insight into the physical processes involved. The early stage of a wire array z-pinch implosion consists of the steady ablation of material from fine metallic wires. Ablated material is accelerated toward the array axis by the J×B force. This flow is highly supersonic (M>5) and becomes super-Alfvénic (MA>2). Radiative cooling is significant in this flow and can be controlled by varying the material in the ablated plasma. The introduction of wires as obstructions in this steady flow leads to the formation of bow shocks, which can be used as a laboratory testbed for astrophysical bow shocks. The magnetic field associated with this obstruction wire can be controlled by varying the current through it. Differences in the shock for different cooling rates and different magnetic fields associated with the obstruction will be discussed, along with comparisons of dimensionless parameters in the experiments to astrophysical systems.
Epitaxially stabilized iridium spinel oxide without cations in the tetrahedral site
Authors: Kuriyama Hiromichi , Matsuno Jobu , Niitaka Seiji , Uchida Masaya , Hashizume Daisuke , Nakao Aiko , Sugimoto Kunihisa , Ohsumi Hiroyuki , Takata Masaki , Takagi Hidenori
Published: May 2010

Single-crystalline thin film of an iridium dioxide polymorph Ir2O4 has been fabricated by the pulsed laser deposition of LixIr2O4 precursor and the subsequent Li-deintercalation using soft chemistry. Ir2O4 crystallizes in a spinel (AB2O4) without A cations in the tetrahedral site, which is isostructural to λ-MnO2. Ir ions form a pyrochlore sublattice, which is known to give rise to a strong geometrical frustration. This Ir spinel was found to be a narrow gap insulator, in remarkable contrast to the metallic ground state of rutile-type IrO2. We argue that an interplay of a strong spin-orbit coupling and a Coulomb repulsion gives rise to an insulating ground state as in a layered perovskite Sr2IrO4.
Role of solid surface structure on evaporative phase change from a completely wetting corner meniscus
Authors: Ojha Manas , Chatterjee Arya , Dalakos George , Wayner Peter C. , Plawsky Joel L.
Published: May 2010

The transport processes that occur at small length scales are greatly influenced by interfacial and intermolecular forces. Surface roughness at the nanoscale generates additional intermolecular interactions that arise due to the increased surface area. In this work, we have experimentally studied how the magnitude as well as the shape of surface roughness influences the microscale transport processes that occur in the contact line region of a liquid corner meniscus. The surface roughness contribution to the interaction potential was calculated and a direct relationship between the wetting properties of the liquid and the underlying surface properties was obtained. Since the underlying roughness alters the surface potential, the shape of the meniscus and in turn, the resulting capillary and disjoining pressure forces also changed. Atomic force microscopy was utilized to obtain a detailed characterization of the shape of the prepared surfaces. Surface morphology features were obtained from a height-height correlation function. These features were related to the wetting and transport properties of the meniscus at the contact line. Finally, the modified capillary and disjoining pressure forces on the structured surfaces were observed to influence the evaporative heat transfer from the corner meniscus.
Oscillation of cylinders of rectangular cross section immersed in fluid
Authors: Brumley Douglas R. , Willcox Michelle , Sader John E.
Published: May 2010

The ability to calculate flows generated by oscillating cylinders immersed in fluid is a cornerstone in micro- and nanodevice development. In this article, we present a detailed theoretical analysis of the hydrodynamic load experienced by an oscillating rigid cylinder, of arbitrary rectangular cross section, that is immersed in an unbounded viscous fluid. We also consider the formal limit of inviscid flow for which exact analytical and asymptotic solutions are derived. Due to its practical importance in application to the atomic force microscope and nanoelectromechanical systems, we conduct a detailed assessment of the dependence of this load on the cylinder thickness-to-width ratio. We also assess the validity and accuracy of the widely used infinitely-thin blade approximation. For thin rectangular cylinders of finite thickness, this approximation is found to be excellent for out-of-plane motion, whereas for in-plane oscillations it can exhibit significant error. A database of accurate numerical results for the hydrodynamic load as a function of the thickness-to-width ratio and normalized frequency is also presented, which is expected to be of value in practical application and numerical benchmarking.
Organic Schottky barrier photovoltaic cells based on MoOx/C60
Authors: Zhang Minlu , Irfan  , Ding Huanjun , Gao Yongli , Tang C. W.
Published: May 2010

We report that the performance of indium tin oxide/molybdenum oxide/fullerene (ITO/MoOx/C60) photovoltaic cells is highly sensitive to the method of depositing MoOx film. The highest open-circuit voltage and short-circuit current are obtained using thermally evaporated MoOx. In contrast, sputtered MoOx produces lower efficiencies. X-ray and ultraviolet photoemission analyses indicate that pristine thermally evaporated MoOx has a high work function of 6.8 eV and Mo6+ oxidation state, whereas argon-sputtered MoOx is characterized by lower work function and coexistence of both Mo6+ and Mo5+ states. The photovoltaic performance of the ITO/MoOx/C60 cells is consistent with MoOx functioning as the Schottky barrier contact.
Microscopic studies of metal-induced lateral crystallization in SiGe
Authors: Itakura Masaru , Masumori Shunji , Kuwano Noriyuki , Kanno Hiroshi , Sadoh Taizoh , Miyao Masanobu
Published: May 2010

Metal-induced lateral crystallization (MILC) in amorphous SiGe films on insulating substrates is an important technique for future thin-film-transistor fabrication. Growth features of low and/or high temperature MILC have been investigated based on the microscopic crystal observation. In the initial stage of MILC, precipitation of hemispherical Ni(Si,Ge) with orthorhombic structure is found at the growth front. This leads to the formation of long needlelike SiGe crystallites. And then, the spontaneous nucleation and growth of SiGe take place around the needlelike crystals, resulting in long rod-shaped SiGe crystals. In this way, the role of Ge atoms on MILC is clarified.
Fast tunnel rates in Si/SiGe one-electron single and double quantum dots
Authors: Thalakulam Madhu , Simmons C. B. , Rosemeyer B. M. , Savage D. E. , Lagally M. G. , Friesen Mark , Coppersmith S. N. , Eriksson M. A.
Published: May 2010

We report the fabrication and measurement of one-electron single and double quantum dots with fast tunnel rates in a Si/SiGe heterostructure. Achieving fast tunnel rates in few-electron dots can be challenging, in part due to the large electron effective mass in Si. Using charge sensing, we identify signatures of tunnel rates in and out of the dot that are fast or slow compared to the measurement rate. Such signatures provide a means to calibrate the absolute electron number and verify single electron occupation. Pulsed gate voltage measurements are used to validate the approach.
Electric charge-mediated coalescence of water droplets for biochemical microreactors
Authors: Jung Yong-Mi , Kang In Seok
Published: May 2010

This work proposes the use of charged droplets driven by the Coulombic force as solution-phase reaction chambers for biological microreactions. A droplet can be charged near an electrode under dc voltage by direct contact to the electrode. This process is called electrical charging of droplet (ECOD). This charged droplet can then be transported rapidly between electrodes following the arc of an electric field line by exploiting electrostatic force. As on-demand electrocoalescence, both alkalization of phenolphthalein and bioluminescence reaction of luciferase in the presence of adenosine triphosphate are studied to test the feasibility of the biochemical microreactors using ECOD. Two oppositely charged droplets are merged to have a color change immediately after microchemical reaction. The applicability of an ECOD-driven droplet to measurement of glucose concentration is also tested. The glucose concentration is measured using a colorimetric enzyme-kinetic method based on Trinder’s reaction [J. Clin. Pathol. 22, 158 (1969)]. The color change in the merged droplet is detected with an absorbance measurement system consisting of a photodiode and a light emitting diode.
Using growth-form attributes to identify pre-settlement woodland trees in central NSW, Australia
Authors: Spooner Peter G. , Lunt Ian D. , Smallbone Lisa
Published: May 2010

Old-growth woodland trees perform many important ecological functions, by providing critical fauna habitat and in sustaining biological diversity. Australian woodlands are dominated by box Eucalyptus species, which are difficult to age accurately using dendrochronology and other well-practiced methods. We aimed to develop a simple field method for identifying pre-settlement (old growth) Eucalyptus trees in south-eastern Australia, using measurements of tree growth-form attributes. We used TwoStep cluster analysis to classify and independently assess trees, and logistic regression analyses to develop models to identify pre-settlement trees in the field based on recorded attributes. Post-settlement (regrowth) trees tended to have a very uniform appearance, whereas the growth-form of older pre-settlement trees greatly varied, in terms of the number of stem and pipe hollows, and number of primary and secondary branches. This clear discrimination between cohorts of trees is discussed in terms of historic changes to disturbance regimes, and resultant impacts on remnant woodland structures. Our results provide a robust method for reliably identifying pre-settlement Eucalyptus trees in the field using tree growth-form measurements, and have broader implications for identifying age cohorts of forest and woodland trees elsewhere.