bluuebunny/crossref_metadata_2025 huggingface dataset:
Investing in Children: Changes in Parental Spending on Children, 1972–2007
Authors: Kornrich Sabino , Furstenberg Frank
Published: September 2012

Parental spending on children is often presumed to be one of the main ways that parents invest in children and a main reason why children from wealthier households are advantaged. Yet, although research has tracked changes in the other main form of parental investment—namely, time—there is little research on spending. We use data from the Consumer Expenditure Survey to examine how spending changed from the early 1970s to the late 2000s, focusing particularly on inequality in parental investment in children. Parental spending increased, as did inequality of investment. We also investigate shifts in the composition of spending and linkages to children’s characteristics. Investment in male and female children changed substantially: households with only female children spent significantly less than parents in households with only male children in the early 1970s; but by the 1990s, spending had equalized; and by the late 2000s, girls appeared to enjoy an advantage. Finally, the shape of parental investment over the course of children’s lives changed. Prior to the 1990s, parents spent most on children in their teen years. After the 1990s, however, spending was greatest when children were under the age of 6 and in their mid-20s.
Arginine exposure alters ectonucleotidase activities and morphology of zebrafish larvae (Danio rerio)
Authors: Capiotti Katiucia Marques , Fazenda Lidiane , Nazario Luiza Reali , Menezes Fabiano Peres , Kist Luiza Wilges , Bogo Maurício Reis , Da Silva Rosane Souza , Wyse Angela Terezinha , Bonan Carla Denise
Published: September 2012

Hyperargininemia is an inborn error of metabolism (IEM) characterized by tissue accumulation of arginine (Arg). Mental retardation and other neurological features are common symptoms in hyperargininemic patients. Considering purinergic signaling has a crucial role from the early stages of development and underlying mechanisms of this disease are poorly established, we investigated the effect of Arg administration on locomotor activity, morphological alterations, and extracellular nucleotide hydrolysis in larvae and adult zebrafish. We showed that 0.1 mM Arg was unable to promote changes in locomotor activity. In addition, 7‐day‐post‐fertilization (dpf) larvae treated with Arg demonstrated a decreased body size. Arg exposure (0.1 mM) promoted an increase in ATP, ADP, and AMP hydrolysis when compared to control group. These findings demonstrated that Arg might affect morphological parameters and ectonucleotidase activities in zebrafish larvae, suggesting that purinergic system is a target for neurotoxic effects induced by Arg.
Pius XI's Promotion of the Italian Model of Catholic Action in the World-Wide Church
Authors: POLLARD JOHN
Published: September 2012

During his pontificate, Pius xi (1922–39) vigorously promoted the ‘export’ of the Italian model of Catholic Action to the rest of the Church as the organisational blueprint for Catholic lay activism, particularly in the battle against atheistic Communism. He was assisted by Mgr, later Cardinal, Giuseppe Pizzardo, the head of Italian Catholic Action. The successes and failures of this campaign are tracked through documents available since the opening of the files of the apostolic nunciatures and delegations and the Extraordinary Ecclesiastical Affairs section of the Secretariat of State for Pius xi's pontificate in the Vatican Archives.
Counting Religion in England and Wales: The Long Eighteenth Century,c.1680–c.1840
Authors: FIELD CLIVE D.
Published: September 2012

The statistical analysis of religion in England and Wales usually commences with the mid-nineteenth century. This article synthesises relevant primary and secondary sources to produce initial quantitative estimates of the religious composition of the population in 1680, 1720, 1760, 1800 and 1840. The Church of England is shown to have lost almost one-fifth of its affiliation market share during this period, with an ever increasing number of nominal Anglicans also ceasing to practise. Nonconformity more than quadrupled, mainly from 1760 and especially after 1800. Roman Catholicism kept pace with demographic growth, but, even reinforced by Irish immigration, remained a limited force in 1840. Judaism and overt irreligion were both negligible.
Forgotten Commons: The Struggle for Recognition and Property Rights in a Spanish Village, 1509–1957
Authors: LANA-BERASAIN JOSÉ-MIGUEL
Published: September 2012

This article studies the role of property rights in social change using the case study of the small village of Sansomáin in Northern Spain between the years 1509 and 1957. The sources are mainly notary and court records and the focus is on the identity of neighbours as the foundation of civil and political rights during the Old Regime, and its translation into the new constitutional order that emerged after the era of the French Revolution. In the village studied, the failure of the Spanish liberal regime in extending the right of citizenship involved the usurpation of the commons by two foreign owners at the expense of the families residing there.
Panics, payments disruptions and the Bank of England before 1826
Authors: James John A.
Published: September 2012

The structures of the banking systems in early nineteenth-century England and later nineteenth-century America were quite similar. In each the multitude of independent country or interior bankers maintained correspondent accounts with bankers in the metropolis, London and New York respectively, to hold reserves and to clear and settle financial instruments used in intercity financial transactions. In spite of such similarities in structure, the performances of the two systems were, however, rather different. Although panics were frequent and their extent widespread in late eighteenth- and early nineteenth-century England involving numerous bank failures, there was never a nationwide paralysis of the payments system such as had become a regular event in late nineteenth-century America. This was due to the Bank of England's functioning as a de facto lender of last resort even though such a role was not explicitly recognized or acknowledged until decades later.
The Effect of the AED and AED Programs on Survival of Individuals, Groups and Populations
Authors: Stokes Nathan Allen , Scapigliati Andrea , Trammell Antoine R. , Parish David C.
Published: September 2012

Objective

The automated external defibrillator (AED) is a tool that contributes to survival with mixed outcomes. This review assesses the effectiveness of the AED, consistencies and variations among studies, and how varying outcomes can be resolved.

Methods

A worksheet for the International Liaison Committee on Resuscitation (ILCOR) 2010 science review focused on hospital survival in AED programs was the foundation of the articles reviewed. Articles identified in the search covering a broader range of topics were added. All articles were read by at least two authors; consensus discussions resolved differences.

Results

AED use developed sequentially. Use of AEDs by emergency medical technicians (EMTs) compared to manual defibrillators showed equal or superior survival. AED use was extended to trained responders likely to be near victims, such as fire/rescue, police, airline attendants, and casino security guards, with improvement in all venues but not all programs. Broad public access initiatives demonstrated increased survival despite low rates of AED use. Home AED programs have not improved survival; in-hospital trials have had mixed results. Successful programs have placed devices in high-risk sites, maintained the AEDs, recruited a team with a duty to respond, and conducted ongoing assessment of the program.

Conclusion

The AED can affect survival among patients with sudden ventricular fibrillation (VF). Components of AED programs that affect outcome include the operator, location, the emergency response system, ongoing maintenance and evaluation. Comparing outcomes is complicated by variations in definitions of populations and variables. The effect of AEDs on individuals can be dramatic, but the effect on populations is limited.

StokesNA, ScapigliatiA, TrammellAR, ParishDC. The effect of the AED and AED programs on survival of individuals, groups and populations. Prehosp Disaster Med.2012;27(5):1–6.
New scientific ocean drilling depth record extends study of subseafloor life
Authors: Showstack Randy
Published: September 2012

The Japanese deep‐sea drilling vessel Chikyu set a new depth record for scientific ocean drilling and core retrieval by reaching a depth of 2119.5 meters below the seafloor (mbsf) on 6 September. This is 8.5 meters deeper than the prior record, set 19 years ago. Three days later, on 9 September, Chikyu set another record by reaching a drilling depth of 2466 mbsf, the maximum depth that will be attempted during the current expedition. The 6 September record was set on day 44 of the Deep Coalbed Biosphere off Shimokita expedition, which is expedition 337 of the Integrated Ocean Drilling Program (IODP). It occurred at drilling site C0020 in the northwestern Pacific Ocean, approximately 80 kilometers northeast from Hachinohe, Japan. The expedition is scheduled to conclude on 30 September.
Space debris tracking needs improvements, report states
Authors: Showstack Randy
Published: September 2012

With more and more space debris littering the skies above Earth, the U.S. Air Force Space Command (AFSPC) needs to keep up with demands to track the debris and prevent collisions with satellites by improving the U.S. Strategic Command's Joint Space Operations Center (JSpOC) infrastructure, modernizing software, and increasing the ability to more easily incorporate new algorithms and sensor data into its system, according to a 6 September report by a U.S. National Research Council committee. “If there is a single message of this study, it is that the Air Force needs to encourage a change in culture to emphasize openness—in transparency of its algorithms, in the interaction of its people with the user community and the scientific community, and in its providing of a reasonable amount of sensor tracking data to the scientific community for testing algorithms,” according to the report, entitled Continuing Kepler's Quest: Assessing Air Force Command's Astrodynamics Standards. “The Air Force needs to position the JSpOC—and its overall space situational awareness system—to rapidly evaluate, adapt, and adopt evolving technologies to meet community needs proactively.”
Davis D. Sentman (1945–2011)
Authors: Williams Earle , Sabbas Fernanda Sao , Shaw Glenn , Nielsen Hans
Published: September 2012

Davis D. Sentman, a geophysicist with wide‐ranging interests but with a primary focus on atmospheric electricity and the originator of the term “sprites” for a type of lightning flash in the mesosphere, first appeared on the planet in a farming community in Iowa City, Iowa, on 19 January 1945. It is noteworthy that when Dave was only 6 months old, his father was struck and killed by lightning while on a tractor. Much later, after a 4‐year stint in the U.S. Air Force and service in the Peace Corps in Kenya, Dave studied mathematics and went on to the University of Iowa to do graduate work with James Van Allen on early space missions, including the 1973 Jupiter encounters by the Pioneer 10 and 11 satellites. At the University of Iowa, he worked on energetic electrons and associated whistler waves in the Jovian inner magnetosphere.
Comparison with observations shows cloud simulations improving
Authors: Balcerak Ernie
Published: September 2012

Climate projections, such as those used by the Intergovernmental Panel on Climate Change, rely on models that simulate physical properties that affect climate, including clouds and water vapor content. Clouds and water vapor are difficult to simulate in global climate models because they are affected by small‐scale physical processes, and cloud feedback on climate is therefore a large source of uncertainty in climate predictions. A new study finds that model simulations of vertically averaged cloud water amount have improved in recent years. Jiang et al. developed a quantitative scoring method to evaluate the accuracy of 19 climate models at various vertical heights between the surface and the tropopause (16–18 kilometers in altitude) over the tropical oceans (30°N–30°S). They compared the models' simulated multiyear mean of cloud water content and water vapor with observations made using several NASA satellites.
Velocity shear layers in solar winds affect Earth's magnetosphere
Authors: Bhattacharya Atreyee
Published: September 2012

Human society is increasingly reliant on technology that can be disrupted by space weather. For instance, geomagnetic storms can cause high‐latitude air fights to be rerouted, costing as much as $100,000 per fight; induce errors of up to 46 meters in GPS systems; and affect satellites and the International Space Station. Space weather is determined by how the solar wind, a stream of hot plasma from the Sun, interacts with Earth's magnetic field. In studying space weather, scientists have largely neglected the fact that the solar wind contains layers of very strong velocity shear. Scientists understand very little about how these wind shears affect space weather.
Nitrous oxide pollution from aircraft to increase by 2050
Authors: Bhattacharya Atreyee
Published: September 2012

The transportation industry is not only one of the biggest sources of air pollution and a significant player in greenhouse gas–induced global warming, but, as a new study shows, the industry could also be responsible for episodes of ozone (O3 ) pollution, particularly over the United States and northern Europe. Combustion of fuel in cars, shipping vessels, and low‐flying aircraft produce nitrogen oxides (NOx), which not only decrease the lifetime of greenhouse gases such as methane but also react with other molecules in the atmosphere to form tropospheric O3, another, more lethal, air pollutant. Hauglustaine and Koff used a global three‐dimensional chemistry‐climate model to investigate how different components of the transportation industry—cars, ships, and low‐flying aircraft—would contribute to NOx pollution over the next few decades under several projected emission scenarios. They found that as road transportation stagnates or even declines due to stricter regulations and congestion, NOx emissions from cars will decrease over time. However, aircraft will increase in number and could contribute between 25% and 48% of NOx emissions, which will be most severe over the United States and Europe—two regions with the highest growth rate in commercial aviation.
Altitude controls carbon dioxide in boreal lakes
Authors: Bhattacharya Atreyee
Published: September 2012

Organic matter present in lakes, derived either from land‐based sources—such as plants, soil, and sediments—or from in situ processes—such as degrading detritus in the water—could be important in the global carbon cycle, and possibly a significant source of the atmospheric carbon dioxide (CO2) budget. The partial pressure of CO2 in surface waters (pCO2) drives the escape of CO2 to the atmosphere. Hence, scientists have long suspected that the relationship between pCO2 and the dissolved organic matter (DOC) in lake waters refects the relative contribution of the environment and in situ processes to the high‐latitude carbon budget. Combining measurements of DOC and pCO2 from nearly 200 lakes across Quebec, Canada, with an additional 13 lake‐based studies from temperate regions across the northern hemisphere, Lapierre and del Giorgio suggest that on a regional scale the A variety of lakes dominate the boreal landscape of Quebec, Canada. elevation of lakes is one of the strongest controls on the relationship between DOC and pCO2 in boreal lakes.
Magma degassing during the Plinian eruption of Novarupta, Alaska, 1912
Authors: Gonnermann H. M. , Houghton B. F.
Published: September 2012

We have modeled the nucleation and isothermal growth of bubbles in dacite from the 1912 Plinian eruption of Novarupta, Alaska. Bubble growth calculations account for the exsolution of H2O and CO2, beginning with bubble nucleation and ending when bubble sizes reproduced the observed size distribution of vesicles in Novarupta pumice clasts. Assuming classical nucleation theory, bubbles nucleated with a diameter of the order of 10−8 m and grew to sizes ranging from 10−6 m to greater than 10−3 m, the typical range of vesicle sizes found in Novarupta pumice. The smallest vesicles in Novarupta pumices are also the most abundant and bubbles with radii of 10−6 m to 10−5 m comprise almost 90% of the entire bubble population. We find that these bubbles must have nucleated and grown to their final size within a few 100 milliseconds. Despite these extremely fast growth rates, the pressures of exsolved volatiles contained within the bubbles remained high, up to about 107Pa in excess of ambient pressure. Assuming a closed‐system, the potential energy of these compressed volatiles was sufficient to cause magma fragmentation, even though only a fraction of the pre‐eruptive volatiles had exsolved. Unless the matrix glasses of Novarupta pyroclasts retains a large fraction of pre‐eruptive volatiles, the majority of magmatic volatiles (80–90%) was likely lost by open‐system degassing between magma fragmentation and quenching.
Challenging the rate‐state asperity model: Afterslip following the 2011 M9 Tohoku‐oki, Japan, earthquake
Authors: Johnson Kaj M. , Fukuda Jun'ichi , Segall Paul
Published: September 2012

Prior to the 2011 M9 Tohoku‐oki earthquake, subduction at the Japan Trench was characterized by M7‐8 earthquakes, sometimes rupturing the same source regions (seismic asperities), followed by extensive afterslip detected by GPS measurements. A physically‐based model consisting of velocity‐weakening asperities surrounded by aseismic creep on velocity‐strengthening regions (the ‘rate‐state asperity model’) became the prevailing conceptual model for earthquakes in this region. Theory and numerical simulation indicates that velocity‐weakening areas do not exhibit sustained afterslip, while velocity‐strengthening regions do not accumulate stress interseismically. Here we demonstrate that the rate‐state asperity model is contradicted by models of postseismic deformation following the Tohoku‐oki earthquake: afterslip in the first eight months either occurred on historical seismic asperities or stress accumulated in regions surrounding the asperities. Unsmoothed inversions of cumulative 8‐month postseismic GPS displacements that restrict afterslip to areas outside of historical ruptures cannot fit the data without afterslip exceeding the slip that fully relaxes the coseismic stress change. In contrast, similarly constrained inversions allowing slip within historical ruptures can satisfactorily fit the postseismic displacements. These results require a modification of the rate‐state asperity model and raise new questions about physical processes and properties of the subduction interface.
Monsoonal influence on Southern Hemisphere 14CO2
Authors: Hua Quan , Barbetti Mike , Levchenko Vladimir A. , D'Arrigo Rosanne D. , Buckley Brendan M. , Smith Andrew M.
Published: September 2012

Annual rings of a cross‐dated teak tree core from Muna Island, Sulawesi, Indonesia in the southern equatorial tropics were analysed for radiocarbon from 1951–1979.14C levels at Muna started rising in 1956 and reached a maximum value of 667‰ in early 1965. The Muna Δ14C levels are significantly higher than those derived from the other Southern Hemisphere (SH) 14C records (including tree rings and atmospheric CO2sampling) for 1959 and 1963–1965. During the growing season of teak tree rings at this location (Nov–Apr) the Inter‐tropical Convergence Zone (ITCZ) moves southward of Muna. Our results indicate that the island is strongly influenced by Northern Hemisphere (NH) air masses carried by the winter Asian monsoon, while the other more southerly SH sites remain covered by SH air masses. This monsoonal effect on atmospheric14C at Muna is evident during the periods of rapidly rising atmospheric 14C (1959 and 1963–1965), when there is an enhanced 14C contrast between northern and southern air masses.
Ocean circulation beneath Larsen C Ice Shelf, Antarctica from in situ observations
Authors: Nicholls Keith W. , Makinson Keith , Venables Emily J.
Published: September 2012

Hot‐water drilled access holes were used to obtain oceanographic data from beneath two sites on Larsen C Ice Shelf, one in the north and one in the south. At both sites the entire water column was colder than the surface freezing point, and the temperature‐salinity characteristics are consistent with a High Salinity Shelf Water source of maximum salinity 34.65 psu. At the southern site the 0.08°C thermal driving at the ice base and the 0.2‐m s−1 rms water speed resulted in a melt rate of 1.3 ± 0.2 m a−1, as measured over an eight‐day period. When combined with the available ship‐based data, the evidence suggests that the sub‐ice cavity is flushed only by water at the surface freezing point. This implies that the reported decrease in surface elevation of Larsen C Ice Shelf is unlikely to be a result of thinning due to an increasing rate of basal melting.
The recent shift in early summer Arctic atmospheric circulation
Authors: Overland James E. , Francis Jennifer A. , Hanna Edward , Wang Muyin
Published: September 2012

The last six years (2007–2012) show a persistent change in early summer Arctic wind patterns relative to previous decades. The persistent pattern, which has been previously recognized as the Arctic Dipole (AD), is characterized by relatively low sea‐level pressure over the Siberian Arctic with high pressure over the Beaufort Sea, extending across northern North America and over Greenland. Pressure differences peak in June. In a search for a proximate cause for the newly persistent AD pattern, we note that the composite 700 hPa geopotential height field during June 2007–2012 exhibits a positive anomaly only on the North American side of the Arctic, thus creating the enhanced mean meridional flow across the Arctic. Coupled impacts of the new persistent pattern are increased sea ice loss in summer, long‐lived positive temperature anomalies and ice sheet loss in west Greenland, and a possible increase in Arctic‐subarctic weather linkages through higher‐amplitude upper‐level flow. The North American location of increased 700 hPa positive anomalies suggests that a regional atmospheric blocking mechanism is responsible for the presence of the AD pattern, consistent with observations of unprecedented high pressure anomalies over Greenland since 2007.
Global M2 internal tide and its seasonal variability from high resolution ocean circulation and tide modeling
Authors: Müller M. , Cherniawsky J. Y. , Foreman M. G. G. , von Storch J.‐S.
Published: September 2012

The present study describes a model simulation, where ocean tide dynamics are simulated simultaneously with the ocean circulation. The model is forced by a lunisolar tidal forcing described by ephemerides and by daily climatological wind stress, heat, and fresh water fluxes. The horizontal resolution is about 0.1° and thus, the model implicitly resolves meso‐scale eddies and internal waves. In this model simulation the globalM2 barotropic to baroclinic tidal energy conversion amounts to 1.2 TW. We show global maps of the surface signature of the M2baroclinic tide and compare it with an estimate obtained from 19 years of satellite altimeter data. Further, the simulated seasonality in the low mode internal tide field is presented and, as an example, the physical mechanisms causing the non‐stationarity of the internal tide generated in Luzon Strait are discussed. In general, this study reveals the impact of inter‐annual changes of the solar radiative forcing and wind forced ocean circulation on the generation and propagation of the low mode internal tides. The model is able to simulate non‐stationary signals in the internal tide field on global scales which have important implications for future satellite altimeter missions.
Initialized decadal predictions of the rapid warming of the North Atlantic Ocean in the mid 1990s
Authors: Robson J. I. , Sutton R. T. , Smith D. M.
Published: September 2012

In the mid 1990s the North Atlantic subpolar gyre (SPG) warmed rapidly, with sea surface temperatures (SST) increasing by 1°C in just a few years. By examining initialized hindcasts made with the UK Met Office Decadal Prediction System (DePreSys), it is shown that the warming could have been predicted. Conversely, hindcasts that only consider changes in radiative forcings are not able to capture the rapid warming. Heat budget analysis shows that the success of the DePreSys hindcasts is due to the initialization of anomalously strong northward ocean heat transport. Furthermore, it is found that initializing a strong Atlantic circulation, and in particular a strong Atlantic Meridional Overturning Circulation, is key for successful predictions. Finally, we show that DePreSys is able to predict significant changes in SST and other surface climate variables related to the North Atlantic warming.
Seismic‐afterslip characterization of the 2010 MW 8.8 Maule, Chile, earthquake based on moment tensor inversion
Authors: Agurto Hans , Rietbrock Andreas , Ryder Isabelle , Miller Matthew
Published: September 2012

On February 27th 2010, a MW8.8 earthquake struck the coast of south‐central Chile, rupturing ∼500 km along the subduction interface. Here we estimate the amount of seismically‐released afterslip (SRA) and the mechanisms underlying the distribution of aftershocks of this megathrust earthquake. We employ data from a temporary local network to perform regional moment tensor (RMT) inversions. Additionally, we relocate global centroid‐moment‐tensor (GCMT) solutions, assembling a unified catalog covering the time period from the mainshock to March 2012. We find that most (70%) of the aftershocks with MW> 4 correspond to thrust events occurring on the megathrust plane, in areas of moderate co‐seismic slip between 0.15 and 0.7 fraction of the maximum slip (Smax). In particular, a concentration of aftershocks is observed between the main patches of co‐seismic slip, where the highest values of SRA are observed (1.7 m). On the other hand, small events, MW< 4, occur in the areas of largest co‐seismic slip (>0.85 Smax), likely related to processes in the damage zone surrounding the megathrust plane. Our study provides insight into the mechanics of the seismic afterslip pattern of this large megathrust earthquake and a quantitative approach to the distribution of aftershocks relative to coseismic slip that can be used for similar studies in other tectonic settings.
The comparative importance of DE3, SE2, and SPW4 on the generation of wavenumber‐4 longitude structures in the low‐latitude ionosphere during September equinox
Authors: Pedatella N. M. , Hagan M. E. , Maute A.
Published: September 2012

Numerical simulations are performed to investigate the generation of the wave‐4 longitude variation in the low‐latitude ionosphere due to the diurnal eastward propagating nonmigrating tide with zonal wavenumber 3 (DE3), semidiurnal eastward propagating nonmigrating tide with zonal wavenumber 2 (SE2), and stationary planetary wave 4 (SPW4). From a fixed local time perspective, the DE3, SE2, and SPW4 all appear as wave‐4 structures in longitude, and thus each of these waves must be considered as a potential source of the wave‐4 variation in the ionosphere. Both theDE3 and SPW4 are found to produce significant wave‐4 variations in the equatorial verticalE × Bdrift velocity, and in the ionospheric peak density (NmF2) at 15°N magnetic latitude. The daytime wave‐4 variation in NmF2 is driven by the combination of verticalE × Bdrift variability and in‐situ effects due largely to meridional neutral winds. The simulation results indicate that theSE2 is not a contributor to the wave‐4 longitude variation. Our results further demonstrate that the actual wave‐4 longitude variation is due to a combination of theDE3 and SPW4. We therefore conclude that, in addition to the DE3, the SPW4 also needs to be considered as an important driver of the wave‐4 longitude variation in the low‐latitude ionosphere. We additionally present evidence for the generation of theSPW4 due to the nonlinear interaction between the migrating diurnal tide and the DE3, and demonstrate the impact of DE3 variability on the amplitude of the SPW4.
Quantifying radial diffusion coefficients of radiation belt electrons based on global MHD simulation and spacecraft measurements
Authors: Tu Weichao , Elkington Scot R. , Li Xinlin , Liu Wenlong , Bonnell J.
Published: September 2012

Radial diffusion is one of the most important acceleration mechanisms for radiation belt electrons, which can be enhanced from drift‐resonant interactions with large‐scale fluctuations of the magnetosphere's magnetic and electric fields (Pc5 range of ULF waves). In order to physically quantify the radial diffusion coefficient,DLL, we run the global Lyon‐Fedder‐Mobarry (LFM) MHD simulations to obtain the mode structure and power spectrum of the ULF waves and validate the simulation results with available satellite measurements. The calculated diffusion coefficients, directly from the MHD fields over a Corotating Interaction Region (CIR) storm in March 2008, are generally higher when solar wind dynamic pressure is enhanced or AE index is high. In contrary to the conventional understanding, our results show that inside geosynchronous orbit the total diffusion coefficient from MHD fields is dominated by the contribution from electric field perturbations, rather than the magnetic field perturbations. The calculated diffusion coefficient has a physical dependence onμ (or electron energy) and L, which is missing in the empirical diffusion coefficient, DLLKp as a function of Kp index, and DLLKp are generally greater than our calculated DLLduring the storm event. Validation of the MHD ULF waves by spacecraft field data shows that for this event the LFM code reasonably well‐reproduces theBz wave power observed by GOES and THEMIS satellites, while the Eφ power observed by THEMIS probes are generally underestimated by LFM fields, on average by about a factor of ten.
Control of Saharan mineral dust transport to Barbados in winter by the Intertropical Convergence Zone over West Africa
Authors: Doherty O. M. , Riemer N. , Hameed S.
Published: September 2012

The reasons for the inter‐annual variability of dust transport from the Sahara across the Atlantic are not well‐understood. Here we address this issue by defining three new climate indices that capture the position and intensity of the zone of near‐surface convergence over West Africa, a part of the global Intertropical Convergence Zone (ITCZ). We then relate these indices to a 38‐year record of mineral dust concentrations at Barbados focusing on the winter season. The results show that the latitudinal displacement of the ITCZ over West Africa and the dust load in Barbados are statistically significantly correlated with a correlation coefficient ofr= −0.69. A southward movement of the ITCZ corresponds to an increased dust load at Barbados. This correlation represents an improvement upon previous results, which focused on traditional teleconnection indices such as the North Atlantic Oscillation or the El‐Niño‐Southern Oscillation. From analyzing composites of wind and precipitation we conclude that for the winter season, the inter‐annual variability of the Barbados dust load is related to changes in near‐surface northeasterly winds in semi‐arid regions in North Africa coincident with the movement of the ITCZ. Changes in precipitation appear to only play a minor role.
Influence of desert dust intrusions on ground‐based and satellite‐derived ultraviolet irradiance in southeastern Spain
Authors: Antón M. , Valenzuela A. , Román R. , Lyamani H. , Krotkov N. , Arola A. , Olmo F. J. , Alados‐Arboledas L.
Published: September 2012

The desert dust aerosols strongly affect propagation of solar radiation through the atmosphere, reducing surface irradiance available for photochemistry and photosynthesis. This paper evaluates effects of desert dust on surface UV erythemal irradiance (UVER), as measured by a ground‐based broadband UV radiometer and retrieved from the satellite Ozone Monitoring Instrument (OMI) at Granada (southern Spain) from January 2006 to December 2010. The dust effects are characterized by the transmittance ratio of the measured UVER to the corresponding modeled clear sky value. The transmittance has an exponential dependency on aerosol optical depth (AOD), with minimum values of ∼0.6 (attenuation of ∼40%). The OMI UVER algorithm does not account for UV aerosol absorption, which results in overestimation of the ground‐based UVER especially during dust episodes with a mean relative difference up to 40%. The application of aerosol absorption post‐correction method reduces OMI bias up to ∼13%. The results highlight great effect of desert dust on the surface UV irradiance in regions like southern Spain, where dust intrusions from Sahara region are very frequent.
Mercury's moment of inertia from spin and gravity data
Authors: Margot Jean‐Luc , Peale Stanton J. , Solomon Sean C. , Hauck Steven A. , Ghigo Frank D. , Jurgens Raymond F. , Yseboodt Marie , Giorgini Jon D. , Padovan Sebastiano , Campbell Donald B.
Published: September 2012

Earth‐based radar observations of the spin state of Mercury at 35 epochs between 2002 and 2012 reveal that its spin axis is tilted by (2.04 ± 0.08) arc min with respect to the orbit normal. The direction of the tilt suggests that Mercury is in or near a Cassini state. Observed rotation rate variations clearly exhibit an 88‐day libration pattern which is due to solar gravitational torques acting on the asymmetrically shaped planet. The amplitude of the forced libration, (38.5 ± 1.6) arc sec, corresponds to a longitudinal displacement of ∼450 m at the equator. Combining these measurements of the spin properties with second‐degree gravitational harmonics (Smith et al., 2012) provides an estimate of the polar moment of inertia of MercuryC/MR2 = 0.346 ± 0.014, where M and R are Mercury's mass and radius. The fraction of the moment that corresponds to the outer librating shell, which can be used to estimate the size of the core, is Cm/C = 0.431 ± 0.025.
Retrospective retrieval of long‐term consistent global leaf area index (1981–2011) from combined AVHRR and MODIS data
Authors: Liu Yang , Liu Ronggao , Chen Jing M.
Published: September 2012

In this paper, we present an approach for generating a consistent long‐term global leaf area index (LAI) product (1981–2011) by quantitative fusion of Moderate Resolution Imaging Spectroradiometer (MODIS) and historical Advanced Very High Resolution Radiometer (AVHRR) data. First, a MODIS LAI series was generated from MODIS data based on the GLOBCARBON LAI algorithm. Then, the relationships between AVHRR observations and MODIS LAI were established pixel by pixel using two data series during overlapped period (2000–2006). Then the AVHRR LAI back to 1981 was estimated from historical AVHRR observations based on these pixel‐level relationships. The long‐term LAI series was made up by combination of AVHRR LAI (1981–2000) and MODIS LAI (2000–2011). The LAI derived from AVHRR was intercompared with that from MODIS during the overlapped period. The results show that the LAIs from these two different sensors are good consistency, with LAI differences are within ±0.6 over 99.0% vegetated pixels. The long‐term LAI was also compared with field measurements, which has an error of 0.81 LAI on average. Compared with the LAI retrieved directly from the GLOBCARBON algorithm, the LAI derived by our method has a lower temporal noise, which means uncertainties from the low quality of AVHRR measurements can be reduced with the aid of high‐quality MODIS data. This product is hosted on the GlobalMapping Web site (http://www.globalmapping.org/globalLAI) for free download, which will provide a long‐term LAI over 30 years for modeling the carbon and water cycles.
A review of nitrogen isotopic alteration in marine sediments
Authors: Robinson Rebecca S. , Kienast Markus , Luiza Albuquerque Ana , Altabet Mark , Contreras Sergio , De Pol Holz Ricardo , Dubois Nathalie , Francois Roger , Galbraith Eric , Hsu Ting‐Chang , Ivanochko Tara , Jaccard Samuel , Kao Shuh‐Ji , Kiefer Thorsten , Kienast Stephanie , Lehmann Moritz , Martinez Philippe , McCarthy Matthew , Möbius Jürgen , Pedersen Tom , Quan Tracy M. , Ryabenko Evgeniya , Schmittner Andreas , Schneider Ralph , Schneider‐Mor Aya , Shigemitsu Masahito , Sinclair Dan , Somes Christopher , Studer Anja , Thunell Robert , Yang Jin‐Yu
Published: September 2012

Nitrogen isotopes are an important tool for evaluating past biogeochemical cycling from the paleoceanographic record. However, bulk sedimentary nitrogen isotope ratios, which can be determined routinely and at minimal cost, may be altered during burial and early sedimentary diagenesis, particularly outside of continental margin settings. The causes and detailed mechanisms of isotopic alteration are still under investigation. Case studies of the Mediterranean and South China Seas underscore the complexities of investigating isotopic alteration. In an effort to evaluate the evidence for alteration of the sedimentary N isotopic signal and try to quantify the net effect, we have compiled and compared data demonstrating alteration from the published literature. A >100 point comparison of sediment trap and surface sedimentary nitrogen isotope values demonstrates that, at sites located off of the continental margins, an increase in sediment 15N/14N occurs during early burial, likely at the seafloor. The extent of isotopic alteration appears to be a function of water depth. Depth‐related differences in oxygen exposure time at the seafloor are likely the dominant control on the extent of N isotopic alteration. Moreover, the compiled data suggest that the degree of alteration is likely to be uniform through time at most sites so that bulk sedimentary isotope records likely provide a good means for evaluating relative changes in the global N cycle.
Transient hydraulic tomography in a fractured dolostone: Laboratory rock block experiments
Authors: Sharmeen Rubaiat , Illman Walter A. , Berg Steven J. , Yeh Tian‐Chyi J. , Park Young‐Jin , Sudicky Edward A. , Ando Ken
Published: September 2012

The accurate characterization of fractured geologic medium, imaging of fracture patterns and their connectivity have been a challenge for decades. Recently, hydraulic tomography has been proposed as a new method for imaging the hydraulic conductivity (K) and specific storage (Ss) distributions of fractured geologic media. While encouraging results have been obtained in the field, the method has not been rigorously assessed in a controlled laboratory setting. In this study, we assess the performance of transient hydraulic tomography (THT) in a fractured dolomitic rock block. The block is characterized through flow‐through tests and multiple pumping tests. The pumping test data were then analyzed with the THT code of Zhu and Yeh (2005) to image the fracture patterns and their connectivity through the delineation of K and Ss distributions (or tomograms). Results show that the THT analysis of pumping tests yields high‐K and low‐Ss zones that capture the fracture pattern and their connectivity quite well and those patterns become more vivid as additional pumping test data are added to the inverse model. The performance of the estimated K and Ss tomograms are then assessed by: (1) comparing the tomograms obtained from synthetic to real data; (2) comparing the tomograms from two different pumping configurations; (3) comparing the estimated geometric mean of the hydraulic conductivity (KG) from the K tomogram to the effective hydraulic conductivity (Keff) estimated from the flow‐through tests; and (4) predicting five independent pumping tests not used in the construction of the K and Ss tomograms. The performance assessment of the K and Ss tomograms reveals that THT is able to image high‐K and low‐Ss zones that correspond to fracture locations in the fractured rock block and that the tomograms can be used to predict drawdowns from pumping tests not used in the construction of the tomograms with reasonable fidelity.
Challenges in the stoichiometric growth of polycrystalline and epitaxial PbZr0.52Ti0.48O3/La0.7Sr0.3MnO3 multiferroic heterostructures using pulsed laser deposition
Authors: Mukherjee Devajyoti , Hyde Robert , Hordagoda Mahesh , Bingham Nicholas , Srikanth Hariharan , Witanachchi Sarath , Mukherjee Pritish
Published: September 2012

High quality polycrystalline and epitaxial PbZr0.52Ti0.48O3/La0.7Sr0.3MnO3 (PZT/LSMO) multiferroic thin films were deposited on single-crystal Si (100) and SrTiO3 (STO) (100) substrates using pulsed laser deposition (PLD) technique. The deposition conditions were optimized to overcome some of the challenges during the growth of stoichiometric PZT/LSMO thin films (with LSMO as the bottom layers). The major setback of the preferential evaporation of Pb during the ablation of PZT target, which leads to the growth of non-stoichiometric, Pb-deficient PZT thin films with poor ferroelectric properties, was investigated by studying the laser-target interaction sites and intensified charge-coupled detector (ICCD) imaging of the laser-ablated plumes. X-ray studies revealed that the PZT/LSMO heterostructures deposited under the optimum conditions were highly crystalline. Atomic force microscope images showed uniform grain growth with surface roughness values as low as 1.6 nm. In- and out-of-plane magnetization measurements showed saturation of 263–310 emu/cm3 and the corresponding absence or presence of magnetic anisotropy in the PZT/LSMO heterostructures on Si and STO substrates, respectively. LSMO/PZT/LSMO capacitors showed high remnant polarizations of 25–44 μC/cm2 at coercive fields of ∼30 kV/cm. A comparative study was performed on the strained epitaxial PZT/LSMO films on STO substrates and the un-strained polycrystalline PZT/LSMO films on Si substrates.
An energy-harvesting scheme utilizing Ga-rich CuIn(1−x)GaxSe2 quantum dots for dye-sensitized solar cells
Authors: Lin Chin-An , Huang K. P. , Ho S. T. , Huang Mei-Wen , He Jr-Hau
Published: September 2012

Ga-rich CuIn(1−x)GaxSe2 (CIGS) quantum dots (QDs) with a wide bandgap of 1.58 eV were utilized in dye-sensitized solar cells for energy harvesting. Ga-rich CIGS QDs at TiO2 photoanodes afford the recombination reduction and thus suppress the dark current, leading to the increase of short-circuit current from 14.47 to 15.27 mA·cm−2 and open-circuit voltage from 751 to 762 mV. This is due to well-adjusted conduction band minimum of Ga-rich CIGS QDs between that of TiO2 and excited state oxidation potential of N719, enhancing the photoelectron collection and suppressing electron back-transfer from TiO2 to oxidized redox species in the electrolyte.
Multiangle static and dynamic light scattering in the intermediate scattering angle range
Authors: Tamborini E. , Cipelletti L.
Published: September 2012

We describe a light scattering apparatus based on a novel optical scheme covering the scattering angle range 0.5° ⩽ θ ⩽ 25°, an intermediate regime at the frontier between wide angle and small angle setups that is difficult to access by existing instruments. Our apparatus uses standard, readily available optomechanical components. Thanks to the use of a charge-coupled device detector, both static and dynamic light scattering can be performed simultaneously at several scattering angles. We demonstrate the capabilities of our apparatus by measuring the scattering profile of a variety of samples and the Brownian dynamics of a dilute colloidal suspension.
A fast neuronal signal-sensitive continuous-wave near-infrared imaging system
Authors: Zhang Zhongxing , Sun Bailei , Gong Hui , Zhang Lei , Sun Jinyan , Wang Bangde , Luo Qingming
Published: September 2012

We have developed a continuous-wave near-infrared imaging system to measure fast neuronal signals. We used a simultaneous sampling method with a separate high-speed analog-to-digital converter for each input channel, which provides a much larger point sample in a digital lock-in algorithm, higher temporal resolution, and lower crosstalk among detected channels. Without any analog filter, digital lock-in detection with a large point sample suppresses noise excellently, making the system less complex and offering better flexibility. In addition, using a custom-made collimator, more photons can reach the brain tissue due to the smaller divergence angle. Performance analysis shows high detection sensitivity (on the order of 0.1 pW) and high temporal resolution (∼50 Hz, 48 channels). Simulation experiments show that intensity changes on the order of 0.01% can be resolved by our instrument when averaging over approximately 500 stimuli. In vivo experiments over the motor cortex show that our instrument can detect fast neuronal signals in the human brain.
Numerical simulations on thermocapillary migrations of nondeformable droplets with large Marangoni numbers
Authors: Yin Zhaohua , Chang Lei , Hu Wenrui , Li Qiaohong , Wang Hongyu
Published: September 2012

In this paper, the study on isolated spherical drops in thermocapillary migrations in zero gravity is carried out with a novel numerical scheme to accomplish long-tank simulations in a very short computing domain, and the full migrating phenomena with fairly large Marangoni numbers (up to 400) are discussed in detail. Larger Marangoni numbers lead to more complicated migrating processes, and longer distances for the drops to reach their final stable migrating velocities (UF). There is nontrivial difference between the UF values in theoretical analysis, numerical simulations, and space experiments, and the most possible reason is the assumed different migrating distances to reach steady states in different investigations.
Light/negative bias stress instabilities in indium gallium zinc oxide thin film transistors explained by creation of a double donor
Authors: Migliorato Piero , Delwar Hossain Chowdhury Md , Gwang Um Jae , Seok Manju , Jang Jin
Published: September 2012

The analysis of current-voltage (I-V) and capacitance-voltage (C-V) characteristics for amorphous indium gallium zinc oxide Thin film transistors as a function of active layer thickness shows that negative bias under illumination stress (NBIS) is quantitatively explained by creation of a bulk double donor, with a shallow singly ionized state ε(0/+) > EC-0.073 eV and a deep doubly ionized state ε(++/+) < EC-0.3 eV. The gap density of states, extracted from the capacitance-voltage curves, shows a broad peak between EC–E = 0.3 eV and 1.0 eV, which increases in height with NBIS stress time and corresponds to the broadened transition energy between singly and doubly ionized states. We propose that the center responsible is an oxygen vacancy and that the presence of a stable singly ionized state, necessary to explain our experimental results, could be due to the defect environment provided by the amorphous network.