bluuebunny/crossref_metadata_2025 huggingface dataset:
Measured and modeled humidification factors of fresh smoke particles from biomass burning: role of inorganic constituents
Authors: Hand J. L. , Day D. E. , McMeeking G. M. , Levin E. J. T. , Carrico C. M. , Kreidenweis S. M. , Malm W. C. , Laskin A. , Desyaterik Y.
Published: July 2010

Abstract. During the 2006 FLAME study (Fire Laboratory at Missoula Experiment), laboratory burns of biomass fuels were performed to investigate the physico-chemical, optical, and hygroscopic properties of fresh biomass smoke. As part of the experiment, two nephelometers simultaneously measured dry and humidified light scattering coefficients (bsp(dry) and bsp(RH), respectively) in order to explore the role of relative humidity (RH) on the optical properties of biomass smoke aerosols. Results from burns of several biomass fuels from the west and southeast United States showed large variability in the humidification factor (f(RH)=bsp(RH)/bsp(dry)). Values of f(RH) at RH=80–85% ranged from 0.99 to 1.81 depending on fuel type. We incorporated measured chemical composition and size distribution data to model the smoke hygroscopic growth to investigate the role of inorganic compounds on water uptake for these aerosols. By assuming only inorganic constituents were hygroscopic, we were able to model the water uptake within experimental uncertainty, suggesting that inorganic species were responsible for most of the hygroscopic growth. In addition, humidification factors at 80–85% RH increased for smoke with increasing inorganic salt to carbon ratios. Particle morphology as observed from scanning electron microscopy revealed that samples of hygroscopic particles contained soot chains either internally or externally mixed with inorganic potassium salts, while samples of weak to non-hygroscopic particles were dominated by soot and organic constituents. This study provides further understanding of the compounds responsible for water uptake by young biomass smoke, and is important for accurately assessing the role of smoke in climate change studies and visibility regulatory efforts.
Impact of Mexico City emissions on regional air quality from MOZART-4 simulations
Authors: Emmons L. K. , Apel E. C. , Lamarque J.-F. , Hess P. G. , Avery M. , Blake D. , Brune W. , Campos T. , Crawford J. , DeCarlo P. F. , Hall S. , Heikes B. , Holloway J. , Jimenez J. L. , Knapp D. J. , Kok G. , Mena-Carrasco M. , Olson J. , O'Sullivan D. , Sachse G. , Walega J. , Weibring P. , Weinheimer A. , Wiedinmyer C.
Published: July 2010

Abstract. An extensive set of measurements was made in and around Mexico City as part of the MILAGRO (Megacity Initiative: Local and Global Research Observations) experiments in March 2006. Simulations with the Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4), a global chemical transport model, have been used to provide a regional context for these observations and assist in their interpretation. These MOZART-4 simulations reproduce the aircraft observations generally well, but some differences in the modeled volatile organic compounds (VOCs) from the observations result from incorrect VOC speciation assumed for the emission inventories. The different types of CO sources represented in the model have been "tagged" to quantify the contributions of regions outside Mexico, as well as the various emissions sectors within Mexico, to the regional air quality of Mexico. This analysis indicates open fires have some, but not a dominant, impact on the atmospheric composition in the region around Mexico City when averaged over the month. However, considerable variation in the fire contribution (2–15% of total CO) is seen during the month. The transport and photochemical aging of Mexico City emissions were studied using tags of CO emissions for each day, showing that typically the air downwind of Mexico City was a combination of many ages. Ozone production in MOZART-4 is shown to agree well with the net production rates from box model calculations constrained by the MILAGRO aircraft measurements. Ozone production efficiency derived from the ratio of Ox to NOz is higher in MOZART-4 than in the observations for moderately polluted air. OH reactivity determined from the MOZART-4 results shows the same increase in relative importance of oxygenated VOCs downwind of Mexico City as the reactivity inferred from the observations. The amount of ozone produced by emissions from Mexico City and surrounding areas has been quantified in the model by tracking NO emissions, showing little influence beyond Mexico's borders, and also relatively minor influence from fire emissions on the monthly average tropospheric ozone column.
Turbulent exchange and segregation of HOx radicals and volatile organic compounds above a deciduous forest
Authors: Dlugi R. , Berger M. , Zelger M. , Hofzumahaus A. , Siese M. , Holland F. , Wisthaler A. , Grabmer W. , Hansel A. , Koppmann R. , Kramm G. , Möllmann-Coers M. , Knaps A.
Published: July 2010

Abstract. The eddy covariance method was applied for the first time to estimate fluxes of OH and HO2 together with fluxes of isoprene, the sum of methyl vinyl ketone (MVK) and methacrolein (MACR) and the sum of monoterpenes above a mixed deciduous forest. Highly sensitive measurements of OH and HO2 were performed by laser induced fluorescence (LIF), and biogenic volatile organic compounds (BVOCs) were measured by Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) at a time resolution of 5 s, each. Wind speed was measured by a sonic anemometer at 10 Hz. The one-day feasibility study was conducted at a total height of 37 m, about 7 m above forest canopy, during the ECHO (Emission and CHemical transformation of biogenic volatile Organic compounds) intensive field study in July 2003. The daytime measurements yielded statistically significant OH fluxes directed downward into the direction of the canopy and HO2 fluxes mainly upward out of the canopy. This hints towards a significant local chemical sink of OH by reactions with BVOCs, other organic and inorganic compounds and conversion of OH to HO2 above the canopy. For OH the measured flux is locally balanced by chemical sources and sinks and direct transport of OH plays no important role for the local chemical OH budget at the measurement height, as expected from the short OH lifetime (<1 s). For HO2 the chemical lifetime (20 s) is in the range of the turbulent transport time for transfer between the top of the canopy and the measuring point. In this case, the radical balance is significantly influenced by both chemistry and transport processes. In addition, the highly time-resolved trace gas measurements were used to calculate the intensity of segregation of OH and BVOCs, demonstrating that the effective reaction rate of isoprene and OH was slowed down as much as 15% due to inhomogeneous mixing of the reactants. The paper describes the results, the applied methods and provides a detailed analysis of possible systematic errors of the covariance products.
Microphysical variability in southeast Pacific Stratocumulus clouds: synoptic conditions and radiative response
Authors: Painemal D. , Zuidema P.
Published: July 2010

Abstract. Synoptic and satellite-derived cloud property variations for the southeast Pacific stratocumulus region associated with changes in coastal satellite-derived cloud droplet number concentrations (Nd) are explored. MAX and MIN Nd composites are defined by the top and bottom terciles of daily area-mean Nd values over the Arica Bight, the region with the largest mean oceanic Nd, for the five October months of 2001, 2005, 2006, 2007 and 2008. The ability of the satellite retrievals to capture composite differences is assessed with ship-based data. Nd and ship-based accumulation mode aerosol concentrations (Na) correlate well (r = 0.65), with a best-fit aerosol activation value dln Nddln Na of 0.56 for pixels with Nd>50 cm−3. The adiabatically-derived MODIS cloud depths also correlate well with the ship-based cloud depths (r=0.7), though are consistently higher (mean bias of almost 60 m). The MAX-Nd composite is characterized by a weaker subtropical anticyclone and weaker winds both at the surface and the lower free troposphere than the MIN-Nd composite. The MAX-Nd composite clouds over the Arica Bight are thinner than the MIN-Nd composite clouds, have lower cloud tops, lower near-coastal cloud albedos, and occur below warmer and drier free tropospheres (as deduced from radiosondes and NCEP Reanalysis). CloudSat radar reflectivities indicate little near-coastal precipitation. The co-occurrence of more boundary-layer aerosol/higher Nd within a more stable atmosphere suggests a boundary layer source for the aerosol, rather than the free troposphere. The MAX-Nd composite cloud thinning extends offshore to 80° W, with lower cloud top heights out to 95° W. At 85° W, the top-of-atmosphere shortwave fluxes are significantly higher (~50%) for the MAX-Nd composite, with thicker, lower clouds and higher cloud fractions than for the MIN-Nd composite. The change in Nd at this location is small (though positive), suggesting that the MAX-MIN Nd composite differences in radiative properties primarily reflects synoptic changes. Circulation anomalies and a one-point spatial correlation map reveal a weakening of the 850 hPa southerly winds decreases the free tropospheric cold temperature advection. The resulting increase in the static stability along 85° W is highly correlated to the increased cloud fraction, despite accompanying weaker free tropospheric subsidence.
Irreversible loss of ice nucleation active sites in mineral dust particles caused by sulphuric acid condensation
Authors: Sullivan R. C. , Petters M. D. , DeMott P. J. , Kreidenweis S. M. , Wex H. , Niedermeier D. , Hartmann S. , Clauss T. , Stratmann F. , Reitz P. , Schneider J.
Published: July 2010

Abstract. During the FROST-2 (FReezing Of duST) measurement campaign conducted at the Leipzig Aerosol Cloud Interaction Simulator (LACIS), we investigated changes in the ice nucleation properties of 300 nm Arizona test dust mineral particles following thermochemical processing by varying amounts and combinations of exposure to sulphuric acid vapour, ammonia gas, water vapour, and heat. The processed aerosol's heterogeneous ice nucleation properties were determined in both the water subsaturated and supersaturated humidity regimes at −30 °C and −25 °C using Colorado State University's continuous flow diffusion chamber. The amount of sulphuric acid coating material was estimated by an aerosol mass spectrometer and from CCN-derived hygroscopicity measurements. The condensation of sulphuric acid decreased the dust particles' ice nucleation ability in proportion to the amount of sulphuric acid added. Heating the coated particles in a thermodenuder at 250 °C – intended to evaporate the sulphuric acid coating – reduced their freezing ability even further. We attribute this behaviour to accelerated acid digestion of ice active surface sites by heat. Exposing sulphuric acid coated dust to ammonia gas produced particles with similarly poor freezing potential; however a portion of their ice nucleation ability could be restored after heating in the thermodenuder. In no case did any combination of thermochemical treatments increase the ice nucleation ability of the coated mineral dust particles compared to unprocessed dust. These first measurements of the effect of identical chemical processing of dust particles on their ice nucleation ability in both water subsaturated and mixed-phase supersaturated cloud conditions revealed that ice nucleation was more sensitive to all coating treatments in the water subsaturated regime. The results clearly indicate irreversible impairment of ice nucleation activity in both regimes after condensation of concentrated sulphuric acid. This implies that the sulphuric acid coating caused permanent chemical and/or physical modification of the ice active surface sites; the possible dissolution of the coating during droplet activation did not restore all immersion/condensation-freezing ability.
A model study on the influence of overshooting convection on TTL water vapour
Authors: Hassim M. E. E. , Lane T. P.
Published: July 2010

Abstract. Overshooting deep convection that penetrates into the Tropical Tropopause Layer (TTL) is thought to have an important role in regulating the water vapour content of this region. Yet, the net effect of such convection and the dominant mechanisms remain unclear. This study uses two idealised three-dimensional cloud-resolving model simulations to examine the influence of overshooting convection on water vapour when it penetrates into two different TTL environments, one supersaturated and the other subsaturated with respect to ice. These simulations show that the overshooting convection plays a direct role in driving the ambient environment towards ice saturation through either net moistening (subsaturated TTL) or net dehydration (supersaturated TTL). Moreover, in these cases the extent of dehydration in supersaturated conditions is greater than the moistening in subsaturated conditions. With the aid of modelled passive tracers, the relative roles of transport, mixing and ice microphysics are assessed; ultimately, ice sublimation and scavenging processes play the most important role in defining the different TTL relative humidity tendencies. In addition, significant moistening in both cases is modelled well into the subsaturated tropical lower stratosphere (up to 450 K), even though the overshooting turrets only reach approximately 420 K. It is shown that this moistening is the result of jumping cirrus, which is induced by the localised upward transport and mixing of TTL air following the collapse of the overshooting turret.
The effect of observation timescales on the characterisation of extreme Mediterranean precipitation
Authors: Camarasa Belmonte A. M. , Soriano García J. , López-García M. J.
Published: July 2010

Abstract. This paper analyses the behaviour of five rainfall indicators (maximum intensity, cumulative rainfall, irregularity, probability of rain and persistence of rain) over different observation timescales ranging from 5 min to 24 h. It covers a large area on the Mediterranean side of the Iberian Peninsula (River Júcar Water Authority, 43 000 km2) on a continuous basis over a period of 14 years (1994–2007). The results show that the behaviour of extreme Mediterranean rainfall is heavily dependent on the observation timescale. There are a number of turning points in the indicator trends which occur on different timescales (1 and 6 h in the case of rain intensity and irregularity, 6 h for cumulative rainfall and between 15 and 30 min for the persistence of rain) and may be relevant for the determination of thresholds used in water management.
Multiple wavelength retrieval of tropospheric aerosol optical properties from MAXDOAS measurements in Beijing
Authors: Clémer K. , Van Roozendael M. , Fayt C. , Hendrick F. , Hermans C. , Pinardi G. , Spurr R. , Wang P. , De Mazière M.
Published: July 2010

Abstract. We report on the retrieval of aerosol extinction profiles at four wavelengths from ground-based multi-axis differential absorption spectroscopy (MAXDOAS) measurements performed in Beijing, China. Measurements were made over a 10-month time period (June 2008 to April 2009) using a newly developed MAXDOAS instrument. A retrieval algorithm, based on an on-line implementation of the radiative transfer code LIDORT and the optimal estimation technique, has been designed to provide near real time information on aerosol extinction vertical profiles. The algorithm was applied to O4 measurements at four wavelengths (360, 477, 577, and 630 nm). The total aerosol optical depths (AODs) calculated from the retrieved profiles exhibit higher values in spring and summer and lower values in autumn and winter. Comparison of the retrieved total AODs with values from a co-located CIMEL sunphotometer revealed a good correlation. The best results are obtained for the UV region with a correlation coefficient (R) of 0.91 and a slope of the linear regression fit of 1.1. At the longest wavelength, R drops down to 0.67 and the slope increases to 1.5. The results confirm that good quality O4 slant column measurements are essential for the success of the retrievals. A method is presented to determine a correction factor to account for systematic errors. It is demonstrated that the algorithm is capable of reliably retrieving aerosol extinction profiles for a wide range of atmospheric conditions (total AODs at 360 nm ranging from about 0.1 to 3). The results open up new perspectives for the extension of the algorithm for the near real time retrieval of trace gas vertical profiles.
Soil respiration at mean annual temperature predicts annual total across vegetation types and biomes
Authors: Bahn M. , Reichstein M. , Davidson E. A. , Grünzweig J. , Jung M. , Carbone M. S. , Epron D. , Misson L. , Nouvellon Y. , Roupsard O. , Savage K. , Trumbore S. E. , Gimeno C. , Curiel Yuste J. , Tang J. , Vargas R. , Janssens I. A.
Published: July 2010

Abstract. Soil respiration (SR) constitutes the largest flux of CO2 from terrestrial ecosystems to the atmosphere. However, there still exist considerable uncertainties as to its actual magnitude, as well as its spatial and interannual variability. Based on a reanalysis and synthesis of 80 site-years for 57 forests, plantations, savannas, shrublands and grasslands from boreal to tropical climates we present evidence that total annual SR is closely related to SR at mean annual soil temperature (SRMAT), irrespective of the type of ecosystem and biome. This is theoretically expected for non water-limited ecosystems within most of the globally occurring range of annual temperature variability and sensitivity (Q10). We further show that for seasonally dry sites where annual precipitation (P) is lower than potential evapotranspiration (PET), annual SR can be predicted from wet season SRMAT corrected for a factor related to P/PET. Our finding indicates that it can be sufficient to measure SRMAT for obtaining a well constrained estimate of its annual total. This should substantially increase our capacity for assessing the spatial distribution of soil CO2 emissions across ecosystems, landscapes and regions, and thereby contribute to improving the spatial resolution of a major component of the global carbon cycle.
Interpretation of GRACE data of the Nile Basin using a groundwater recharge model
Authors: Bonsor H. C. , Mansour M. M. , MacDonald A. M. , Hughes A. G. , Hipkin R. G. , Bedada T.
Published: July 2010

Abstract. Assessing and quantifying natural water storage is becoming increasingly important as nations develop strategies for economic growth and adaptations measures for climate change. The Gravity Recovery and Climate Experiment (GRACE) data provide a new opportunity to gain a direct and independent measure of water mass variations on a regional scale. Hydrological models are required to interpret these mass variations and partition them between different parts of the hydrological cycle, but groundwater storage has generally been poorly constrained by such models. This study focused on the Nile basin, and used a groundwater recharge model ZOODRM (Zoomable Object Oriented Distributed Recharge Model) to help interpret the seasonal variation in terrestrial water storage indicated by GRACE. The recharge model was constructed using almost entirely remotely sensed input data and calibrated to observed hydrological data from the Nile. GRACE data for the Nile Basin indicates an annual terrestrial water storage of approximately 200 km3: water input is from rainfall, and much of this water is evaporated within the basin since average annual outflow of the Nile is less than 30 km3. Total annual recharge simulated by ZOODRM is 400 km3/yr; 0–50 mm/yr within the semi arid lower catchments, and a mean of 250 mm/yr in the sub-tropical upper catchments. These results are comparable to the few site specific studies of recharge in the basin. Accounting for year-round discharge of groundwater, the seasonal groundwater storage is 100–150 km3/yr and seasonal change in soil moisture, 30 km3/yr. Together, they account for between 50 and 90% of the annual water storage in the catchment. The annual water mass variation (200 km3/yr) is an order of magnitude smaller than the rainfall input into the catchment (2000 km3/yr), which could be consistent with a high degree of moisture recycling within the basin. Future work is required to advance the calibration of the ZOODRM model, particularly improving the timing of runoff routing.
Interdisciplinary analysis of soil acidification hazard and its legacy effects in Lithuania
Authors: Eidukeviciene M. , Volungevicius J. , Marcinkonis S. , Tripolskaja L. , Karcauskiene D. , Fullen M. A. , Booth C. A.
Published: July 2010

Abstract. An analysis of factors influencing effective soil acidification management is reported. This analysis was conducted simultaneously at both national and local levels. These investigations were accomplished in three stages: (i) validation of acid soil spatial patterns using systems analysis and geoinformation methods; (ii) spatial statistical analysis of soil pH diversity using a statistical grid method; and (iii) development of the concept of soil acidity management. Results indicate the national spatial distribution of topsoil reaction is a natural and stable phenomenon related to Quaternary sub-surface deposits. However, secondary effects of topsoil liming are evident in both spatial and temporal soil reaction patterns.
Decrease of VLF transmitter signal and Chorus-whistler waves before l'Aquila earthquake occurrence
Authors: Boudjada M. Y. , Schwingenschuh K. , Döller R. , Rohznoi A. , Parrot M. , Biagi P. F. , Galopeau P. H. M. , Solovieva M. , Molchanov O. , Biernat H. K. , Stangl G. , Lammer H. , Moldovan I. , Voller W. , Ampferer M.
Published: July 2010

Abstract. We investigate the VLF emissions observed by the Instrument Champ Electrique (ICE) experiment onboard the DEMETER micro-satellite. We analyze intensity level variation 10 days before and after the occurrence of l'Aquila earthquake (EQ). We found a clear decrease of the VLF received signal related to ionospheric whistler mode (mainly Chorus emission) and to signal transmitted by the DFY VLF station in Germany, few days (more than one week) before the earthquake. The VLF power spectral density decreases of more than two orders of magnitude until the EQ, and it recovers to normal levels just after the EQ occurrence. The geomagnetic activity is principally weak four days before EQ and increases again one day before l'Aquila seismic event. Our results are discussed in the frame of short- and long-terms earthquakes prediction focusing on the crucial role of the magnetic field of the Earth.
Preclinical validation of salivary biomarkers for primary Sjögren's syndrome
Authors: Hu Shen , Gao Kai , Pollard Rodney , Arellano‐Garcia Martha , Zhou Hui , Zhang Lei , Elashoff David , Kallenberg Cees G. M. , Vissink Arjan , Wong David T.
Published: July 2010

Objective

Sjögren's syndrome (SS) is a systemic autoimmune disease with a variety of presenting symptoms that may delay its diagnosis. We previously discovered a number of candidate salivary biomarkers for primary SS using both mass spectrometry and expression microarray analysis. In the current study, we aimed to verify these candidate biomarkers in independent patient populations and to evaluate their predictive values for primary SS detection.

Methods

In total, 34 patients with primary SS, 34 patients with systemic lupus erythematosus (SLE), and 34 healthy individuals were enrolled for the validation studies. Salivary protein biomarkers were measured using either Western blotting or enzyme‐linked immunosorbent assay, and the messenger RNA (mRNA) biomarkers were measured using quantitative polymerase chain reaction. Statistical analysis was performed using R software, version 2.9.

Results

Three protein biomarkers (cathepsin D [CPD], α‐enolase, and β2‐microglobulin [β2m]) and 3 mRNA biomarkers (myeloid cell nuclear differentiation antigen [MNDA], guanylate binding protein 2 [GBP‐2], and low‐affinity IIIb receptor for the Fc fragment of IgG) were significantly elevated in patients with primary SS compared with both SLE patients and healthy controls. The combination of 3 protein biomarkers, CPD, α‐enolase, and β2m, yielded a receiver operating characteristic (ROC) value of 0.99 in distinguishing primary SS from healthy controls. The combination of protein biomarkers β2m and 2 mRNA biomarkers, MNDA and GBP‐2, reached an ROC of 0.95 in discriminating primary SS from SLE.

Conclusion

We have successfully verified a panel of protein and mRNA biomarkers that can discriminate primary SS from both SLE and healthy controls. If further validated in patients with primary SS and those with sicca symptoms but no autoimmune disease, these biomarkers may lead to a simple yet highly discriminatory clinical tool for diagnosis of primary SS.
Exploring the relationship between weaning and infant mortality: An isotope case study from Aşıklı Höyük and Çayönü Tepesi
Authors: Pearson J.A. , Hedges R.E.M. , Molleson T.I. , Özbek M.
Published: July 2010

We measured stable nitrogen isotope ratios in bone collagen of 60 individuals from the early Neolithic (9th–8th millennium Cal. BC) sites of Çayönü Tepesi and Aşıklı Höyük. Our aim was to identify the duration of exclusive breastfeeding (EBF), compare this with juvenile mortality at each site, and assess whether there was a relationship between them. The isotope analysis suggests that weaning commenced at about 1 year at Aşıklı Höyük and around 2 years at Çayönü Tepesi. The mortality data show equal numbers of infant deaths up to 24 months; however, after 24 months, the mortality rate increases at Çayönü Tepesi, and a Student's t‐test confirms a significant difference in infant mortality between the sites. Weaning foods prepared in the early Neolithic from agricultural crops would have had low‐iron content, poor nutritional value, and would have been prepared in nonsterilized containers. Therefore, later weaned infants in early Neolithic farming settlements, although capable of some immunological response, were probably undernourished putting them at a disadvantage when encountering bacteria in their weaning food. Our results suggest that infant feeding regimes that introduced infants to weaning foods in the first year of life may have had a positive effect on their survival. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.
Genetic and environmental contributions to variation in baboon cranial morphology
Authors: Roseman Charles C. , Willmore Katherine E. , Rogers Jeffrey , Hildebolt Charles , Sadler Brooke E. , Richtsmeier Joan T. , Cheverud James M.
Published: July 2010

The development, function, and integration of morphological characteristics are all hypothesized to influence the utility of traits for phylogenetic reconstruction by affecting the way in which morphological characteristics evolve. We use a baboon model to test the hypotheses about phenotypic and quantitative genetic variation of traits in the cranium that bear on a phenotype's propensity to evolve. We test the hypotheses that: 1) individual traits in different functionally and developmentally defined regions of the cranium are differentially environmentally, genetically, and phenotypically variable; 2) genetic covariance with other traits constrains traits in one region of the cranium more than those in others; 3) and regions of the cranium subject to different levels of mechanical strain differ in the magnitude of variation in individual traits. We find that the levels of environmental and genetic variation in individual traits are randomly distributed across regions of the cranium rather than being structured by developmental origin or degree of exposure to strain. Individual traits in the cranial vault tend to be more constrained by covariance with other traits than those in other regions. Traits in regions subject to high degrees of strain during mastication are not any more variable at any level than other traits. If these results are generalizable to other populations, they indicate that there is no reason to suppose that individual traits from any one part of the cranium are intrinsically less useful for reconstructing patterns of evolution than those from any other part. Am J Phys Anthropol 143:1–12, 2010. © 2010 Wiley‐Liss, Inc.
Bias and accuracy of age estimation using developing teeth in 946 children
Authors: Liversidge Helen M. , Smith B. Holly , Maber Melissa
Published: July 2010

Developing teeth are used to assess maturity and estimate age in several disciplines. The aim of the study was to determine which of the most well known dental age estimation methods was best at estimating age. The target sample of dental radiographs (N = 946, ages 3–16) was described by Maber et al. (Forensic Sci Int 159 (2006) S68–S73). Seven mandibular permanent teeth (I1–M2) were assessed, and dental age was calculated using four dental maturity scales and fifteen methods that use data for individual teeth. The mean difference between dental age and real age was calculated (bias) as well as several other measures of accuracy (mean/median absolute difference, percentage aged to within six months and to within 10% of real age). Most methods estimated age with significant bias and standard deviation of bias ranged from 0.86 to 1.03 years. Analysis by age group showed most methods over‐aged younger children, and considerably under‐aged older children. The method that performed best was the dental maturity scale of Willems et al. (J Forensic Sci 46 (2001) 893–895) with bias of −0.14 ± 0.86 years (N = 827), mean absolute difference of 0.66 years, 71% aged to 10% or less of age, and 49% aged to within six months. Two individual teeth, P2 and M2, estimated age with bias not significantly different to zero for most formation stages using methods based on a large reference sample (L9a Demirjian stages) and a uniform age distribution (N25a Moorrees stages). Standard deviation of bias was least for early crown stages and most for late root stages. Methods that average ages for individual teeth improve if schedules for ‘mean age entering a stage’ are adjusted for prediction. Methods that directly calculate ‘mean age within stage’ can be improved by drawing from a uniform age distribution. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.
Encephalization, expensive tissues, and energetics: An examination of the relative costs of brain size in strepsirrhines
Authors: Barrickman Nancy L. , Lin Maggie J.
Published: July 2010

The evolution of encephalization requires that energetic challenges be met. Several hypotheses, such as the maternal energy and expensive tissue hypotheses, have been proposed to explain how some species are able to provide adequate energetic resources for large brains. The former incorporates maternal investment strategies, such as extended life history and elevated resting metabolic rate, which contribute to the growth of a large brain. The latter incorporates the reduction of gut size, which increases available energy for the maintenance of adult brain size. This study examines a sample of strepsirrhines, testing the hypothesis that encephalized species utilize some combination of the above‐mentioned strategies. Infants and juveniles from three species at the Duke Lemur Center (DLC) were measured periodically to arrive at head and body growth trajectories. These data were used to determine the energetic tradeoff among the offspring. The examination of gestation length, weaning age, intestinal size and resting metabolic rate was used to assess adult brain maintenance and maternal energetic contribution. The results reveal thatDaubentonia, the most encephalized and thus human‐like of the lemurs, does not experience an energetic trade‐off between brain and body during ontogeny, but does exhibit a trade‐off between extensive brain growth and possibly reduced intestinal growth. Also, maternal energy is utilized. Encephalized lemurs, such asDaubentonia, have higher resting metabolic rate, while encephalized lorisiforms have a longer period of gestation. These results demonstrate that there are several strategies for meeting the energetic demands of encephalization, and they can be manifested differentially across taxa. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.
The influence of body proportions on femoral and tibial midshaft shape in hunter‐gatherers
Authors: Shaw Colin N. , Stock Jay T.
Published: July 2010

Variation in femoral and tibial diaphyseal shape is used as an indicator of adaptation to patterns of terrestrial mobility. Recent experimentation has implied that lower limb diaphyseal shape may be primarily influenced by lower limb length, and less so by mobility patterns. If valid, this would, at most, render previous interpretations of mobility patterns based on analyses of diaphyseal shape questionable, and, at least, require additional standardization that considers the influence of limb length. Although the consequences could be profound, this implication has yet to be directly tested. Additionally, the influence of body breadth on tibial shape (and to a lesser extent femoral shape) remains uncertain. Tibial and femoral cross‐sectional midshaft shape measurements, taken from nine Pleistocene and Holocene skeletal populations, were compared against lower limb length, limb segment length, and bi‐iliac breadth. Generally, limb length and limb segment length do not significantly influence femoral or tibial midshaft shape. After controlling for body mass greater bi‐iliac breadth is associated with a relative mediolateral strengthening of the femoral midshaft, while the influence of a wider body shape (BIB/length) is associated with a relative M‐L strengthening of the tibia and femur of males, and the tibia of females. We conclude that; (1) mechanical interpretations of lower limb diaphyseal shape are most parsimonious due to the lack of evidence for a consistent relationship between segment length and shape; however, (2) further work is required to investigate the influence of bi‐iliac breadth on both femoral and tibial midshaft shape. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.
Photoluminescent and oxygen sensing properties of core–shell nanospheres based on a covalently grafted ruthenium(II) complex
Authors: Wang Shuli , Li Bin , Zhang Liming , Liu Lina , Wang Yinghui
Published: July 2010

SiO2 nanospheres coated with silica chemically doped with a ruthenium complex [Ru(Bphen)2PhenSi]Cl2 (denoted as Ru, there Bphen = 4,7‐diphenyl‐1,10‐phenanthrolin, PhenSi = modified 1,10‐phenathroline) were prepared using a simple solution‐based method. Field‐emission scanning electron microscopy (FE‐SEM) showed that the pure SiO2 nanospheres with a mean diameter of ∼185 nm were successfully coated with Ru complex–chemically doped SiO2 shell with a thickness of ∼45 nm. The obtained core‐shell nanosphere materials exhibited bright red triplet metal‐to‐ligand charge transfer (3MLCT) emission, and their photoluminescent intensity was sensitive to oxygen concentration. These properties make them promising candidates for biomarkers and optical oxygen sensors, which can measure the O2 concentration in biological fluids. Copyright © 2010 John Wiley & Sons, Ltd.
Inhibition of T cell–dependent and RANKL‐dependent osteoclastogenic processes associated with high levels of bone mass in interleukin‐15 receptor–deficient mice
Authors: Djaafar Souad , Pierroz Dominique D. , Chicheportiche Rachel , Zheng Xin Xiao , Ferrari Serge L. , Ferrari‐Lacraz Sylvie
Published: July 2010

Objective

T cell production of RANKL, interferon‐γ (IFNγ), and other cytokines in inflammatory processes such as rheumatoid arthritis or secondary to conditions such as estrogen deficiency stimulates osteoclast activity, which leads to bone resorption and bone loss. The purpose of this study was to characterize the effects of interleukin‐15 (IL‐15), a master T cell growth factor whose role in bone remodeling remains unknown.

Methods

We used mice lacking the IL‐15 receptor (IL‐15Rα−/−) to investigate the effects of IL‐15 on osteoclast development, T cell and dendritic cell activation in vitro and in vivo, bone mass, and microarchitecture in intact and ovariectomized (OVX) mice.

Results

In wild‐type (WT) animals, IL‐15 and RANKL provided a costimulatory signal for osteoclast development. Spleens from IL‐15Rα−/− mice contained few c‐Kit+ osteoclast precursors, and the expression of NF‐ATc1 and the osteoclastogenic response to RANKL were impaired. In addition, dendritic cell–dependent and T cell–dependent mechanisms of osteoclast activation, including RANKL and IFNγ production, were impaired in IL‐15Rα−/− mice. In turn, IL‐15Rα−/− T cells failed to stimulate WT osteoclasts, whereas WT T cells failed to stimulate IL‐15Rα−/− osteoclasts. Compared with WT mice, both intact and OVX IL‐15Rα−/− mice had significantly greater bone mineral density and microarchitecture, including a higher trabecular bone volume fraction and cortical thickness. The numbers of osteoclasts on the bone surface as well as markers of bone turnover were significantly decreased in IL‐15Rα−/− mice.

Conclusion

In the absence of IL‐15 signaling, several converging mechanisms of osteoclastogenesis are inhibited, both directly and indirectly, through T cells, which leads to a high bone mass phenotype. Targeting the IL‐15 pathway may represent a novel therapeutic approach to treating primary and secondary osteoporosis.
Testbed for evaluation of vehicular detection systems
Authors: Chitturi Madhav V. , Medina Juan C. , Benekohal Rahim (Ray) F.
Published: July 2010

Reliable and robust detection systems are the cornerstone in the efficient and proper functioning of vehicle infrastructure integration. This paper presents the design and implementation of a testbed for evaluating vehicular detection systems. The development of the testbed involved design of the hardware setup required for real‐time monitoring of the sensors, programming the devices for data capture, and development of algorithms to automate the analysis of the recorded data. The methodology used to calibrate and validate the algorithms to automate the analysis of the data is presented as well. Although the testbed is presented in the context of evaluation of video detection systems at signalized intersections, it can be used for evaluating any vehicular detection systems. Copyright © 2010 John Wiley & Sons, Ltd.
Hexamer oligonucleotide topology and assembly under solution phase NMR and theoretical modeling scrutiny
Authors: Evstigneev Maxim P. , Parkinson John A. , Lantushenko Anastasia O. , Kostjukov Viktor V. , Pahomov Valery I.
Published: July 2010

The entire family of noncomplementary hexamer oligodeoxyribonucleotides d(GCXYGC) (X and Y = A, G, C, or T) were assessed for topological indicators and equilibrium thermodynamics using a priori molecular modeling and solution phase NMR spectroscopy. Feasible modeled hairpin structures formed a basis from which solution structure and equilibria for each oligonucleotide were considered. 1H and 31P variable temperature‐dependent (VT) and concentration‐dependent NMR data, NMR signal assignments, and diffusion parameters led to d(GCGAGC) and d(GCGGGC) being understood as exceptions within the family in terms of self‐association and topological character. A mean diffusion coefficient D298 K = (2.0 ± 0.07) × 10−10 m2 s−1 was evaluated across all hexamers except for d(GCGAGC) (D298 K = 1.7 × 10−10 m2 s−1) and d(GCGGGC) (D298 K = 1.2 × 10−10 m2 s−1). Melting under VT analysis (Tm = 323 K) combined with supporting NMR evidence confirmed d(GCGAGC) as the shortest tandem sheared GA mismatched duplex. Diffusion measurements were used to conclude that d(GCGGGC) preferentially exists as the shortest stable quadruplex structure. Thermodynamic analysis of all data led to the assertion that, with the exception of XY = GA and GG, the remaining noncomplementary oligonucleotides adopt equilibria between monomer and duplex, contributed largely by monomer random‐coil forms. Contrastingly, d(GCGAGC) showed preference for tandem sheared GA mismatch duplex formation with an association constant K = 3.9 × 105M−1. No direct evidence was acquired for hairpin formation in any instance although its potential existence is considered possible for d(GCGAGC) on the basis of molecular modeling studies. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 1023–1038, 2010.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
R&D activity in Canada: does corporate ownership structure matter?
Authors: Di Vito Jackie , Laurin Claude , Bozec Yves
Published: July 2010

This study examines the link between ownership structures and R&D activities in Canada. We hypothesize that highly concentrated ownership structures or the presence of controlling minority shareholders negatively affects R&D intensity of Canadian manufacturing firms. Our results show that the concentration of voting rights is negatively related to the level of R&D expenditure and R&D outcomes. Furthermore, we show that the level of separation between the voting and cash flow rights held by dominant shareholders of “Controlling Minority Structure” firms has a positive effect on R&D intensity but a negative effect on R&D outcomes. Copyright © 2010 ASAC. Published by John Wiley & Sons, Ltd.
Numerical study of drop spreading over saturated pores
Authors: Lunkad Siddhartha F. , Maiti R. N. , Buwa Vivek V. , Nigam K. D. P.
Published: July 2010

Numerical study of the dual effect of pores in liquid spreading over porous surface (flat and spherical) whereby liquid movement is facilitated as well as restricted (visualised by Khanna and Nigam [Khanna and Nigam, Chem. Eng. Sci. 57, 3401–3405 (2002)]) is presented to improve the present understanding of wetting. Using the volume of fluid (VOF) method in a two‐dimensional solution domain, the influence of various parameters viz. drop volume, pore density, surface wettability and liquid properties on the liquid spreading over 2D pellets with saturated pores was numerically investigated. Simulation results were found to capture the key features of the liquid spreading over non‐porous and porous surfaces qualitatively. The variation of spread factor and the apex height of liquid film with time were in a good qualitative agreement with the concept of dual action of pores. The liquid spreading was observed to have a direct proportionality with the pore density, that is, higher the number of pores, better was the liquid spreading. It was also observed that the influence of the pores on the liquid spreading was reduced with decrease in the surface wettability. It is expected that this numerical analysis of the liquid droplet spreading over saturated porous surface will be useful for better understanding of the physics of drop and pore (saturated) interactions.
Surface fractal dimension of rice hull‐derived charcoal from a fluidized‐bed reactor
Authors: Fan L. T. , Boateng A. A. , Walawender W. P.
Published: July 2010

Disposal of or energy recovery from rice hull can be accomplished by pyrolysis, a heterogeneous reaction whose rate tends to depend on the area of the solid reactant surface. In the present work, the surface fractal dimension, dSF an intrinsic quantitative measure for characterizing irregular particle surfaces, has been determined for rice hull as 2.42. The values of dSF of hull‐derived charcoal particles at a retention time of 30 s in a fluidized bed have been determined to be 2.79 at 848 K and 3.00 at 973 and 1173 K, thereby indicating the development of a highly porous network with increasing temperature.
Absorption of carbon monoxide with reversible reaction in cualcl4‐toluene‐complex solutions
Authors: Gholap Raghuraj V. , Chaudhari Raghunath V.
Published: July 2010

The absorption of CO in CuAlCl4‐toluene‐complex solutions was studied in a stirred reactor. The reaction was found to occur in a fast reaction regime. The effect of CO partial pressure, CuAlCl4‐toluene‐complex concentration and temperature on the rate of absorption was studied. The results have been interpreted using a theoretical model for mass transfer with reversible chemical reaction and the rate parameters were determined. The equilibrium constants were also determined experimentally. An interesting observation showing a decrease in the rate with an increase in temperature was made for this system. This is explained on the basis of a higher activation energy for the reverse reaction. The activation energies evaluated for the forward and reverse reactions are 32.93 and 97.42 kJ/mol, respectively.
Size distribution of the particles entrained from fluidized beds: Gas humidity effects
Authors: Baron T. , Hazlett J. D. , Bergougnou M. A. , Briens C. L. , Galtier P.
Published: July 2010

Experimental results obtained with 65 μm sand and 69 μm cracking catalyst showed that the smallest particles were not the most easily elutriated from fluidized beds of mixed size particles. This is in contradiction with the assumption applied to existing models for the prediction of the flux and size distribution of particles elutriated from a fluidized bed. The smallest particles cannot be removed by elutriation from a mixture of particles of various sizes.

The smallest particles may be agglomerated with larger particles. Increasing the gas humidity, which would presumably reduce electrostatic effects, did not greatly affect the size distribution of the elutriated particles.
Hydrodynamique et transfert gaz‐liquide dans un réacteur verlifix rempli de différents garnissages
Authors: Tahraoui K. , Ronze D. , Zoulalian A.
Published: July 2010

L'étude porte sur différents réacteurs triphasés du type Verlifix constitués par l'association en série d'un venturi à jet placé en amont d'une colonne remplie d'un garnissage. Les écoulements de gaz et de liquide se font à co‐courant descendant. Quatre types de garnissage ont été disposés dans la colonne, à savoir: des anneaux Raschig, des blocs de monolithe alvéolaire, des particules d'alumine microporeuses et des billes de verre. Pour les quatre supports et pour des conditions opératoires fixées, nous mesurons certaines caractéristiques hydrodynamiques du lit fixe et du réacteur et les caractéristiques de transfert gaz‐liquide du co'té liquide du réacteur dans son ensemble. Les différentes mesures permettent de mettre en évidence l'influence du type de garnissage sur les grandeurs mesurées et plus particulièrement sur le coefficient de transfert volumique du réacteur.
Air bubble holdup in quiescent wood pulp suspensions
Authors: Pelton Robert , Piette Richard
Published: July 2010

Air bubbles were injected into the bottom of a column filled with an aqueous suspension of wood pulp fibers to permit measurement of the probability that the bubbles escape the fiber network to reach the surface. Escape probabilities were measured as functions of bubble volume, pulp consistency (weight fraction of fibers), and pulp type. For a given consistency, larger bubbles rose through the column whereas smaller bubbles were held up in the fiber network. The higher the consistency, the greater the bubble diameter required for escape. The minimum buoyancy forces required for bubble escape were correlated with estimates of the yield stress of the fiber network.
Combined buoyancy effects of thermal and mass diffusion on laminar forced convection in the thermal entrance region of horizontal square channels
Authors: Lin J. N. , Chou F. C. , Yan W. M. , Tzeng P. Y.
Published: July 2010

Heat and mass transfer in laminar mixed convection in the thermal entrance region of horizontal square channels is investigated by using the vorticity‐velocity formulation of the Naiver‐Stokes equations. The numerical results, including the developments of temperature and concentration contours, Nuz and friction coefficient ratios, fRe / (fRe)0, are presented for an air‐water system. The effects of bottom wall temperature and the relative humidity on the momentum, heat and mass transfer in the flow are examined in detail. Results show that the influences of the evaporation of the water vapor along the wetted wall on the heat and mass transfer and the ratio fRe / (fRe)0 are rather substantial.