bluuebunny/crossref_metadata_2025 huggingface dataset:
Longitudinal Brain Size Measurements in App/Ps1 Transgenic Mice
Authors: Vincent Trevor J. , Thiessen Jonathan D. , Kurjewicz Laryssa M. , Germscheid Shelley L. , Turner Allan J. , Zhilkin Peter , Alexander Murray E. , Martin Melanie
Published: February 2011

There appear to be species differences among the effects of gene mutations related to familial Alzheimer's disease on the brain during aging. To gain a better understanding of the effects of the Swedish mutation of amyloid precursor protein and the mutant form of human presenilin 1 on mice, commercially available mice from Jackson Laboratory were studied. Three dimensional T2*-weighted imaging was used to monitor the size of brains of APP/PS1 mice monthly, from 6 to 13 months of age. No significant difference was measured in the size of the medial-lateral width, dorsal-ventral height, rostral-caudal length or the volume of the APPSwe/ PS1 mouse brain. Faster and higher-resolution imaging methods are needed to accurately determine if small volume or shape changes occur in mouse brains with age or gene mutations.
Antioxidant Supplements Improve Profiles of Hepatic Oxysterols and Plasma Lipids in Butter-fed Hamsters
Authors: Poirier Johanne , Cockell Kevin A. , Ratnayake W.M. Nimal , Scoggan Kylie A. , Hidiroglou Nick , Gagnon Claude , Rocheleau Hélène , Gruber Heidi , Griffin Philip , Madère René , Trick Keith , Kubow Stan
Published: February 2011

Hypercholesterolemia diets are associated with oxidative stress that may contribute to hypercholesterolemia by adversely affecting enzymatically-generated oxysterols involved in cholesterol homeostasis. An experiment was conducted to examine whether the cholesterol-lowering effects of the antioxidants selenium and α-tocopherol were related to hepatic oxysterol concentrations. Four groups of male Syrian hamsters (n = 7-8) were fed high cholesterol and saturated fat (0.46% cholesterol, 14.3% fat) hypercholesterolemic semi-purified diets: 1) Control; 2) Control + α-tocopherol (67 IU all-racemic-α-tocopheryl-acetate/kg diet); 3) Control + selenium (3.4 mg selenate/kg diet); and 4) Control + α-tocopherol + selenium. Antioxidant supplementation was associated with lowered plasma cholesterol concentrations, decreased tissue lipid peroxidation and higher hepatic oxysterol concentrations. A second experiment examined the effect of graded selenium doses (0.15, 0.85, 1.7 and 3.4 mg selenate/kg diet) on mRNA expression of the oxysterol-generating enzyme, hepatic 27-hydroxylase (CYP27A1, EC 1.14.13.15), in hamsters (n = 8-9) fed the hypercholesterolemic diets. Supplementation of selenium at 3.4 mg selenate/kg diet was not associated with increased hepatic 27-hydroxylase mRNA. In conclusion, the cholesterol lowering effects of selenium and α-tocopherol were associated with increased hepatic enzymatically generated oxysterol concentrations, which appears to be mediated via improved antioxidant status rather than increased enzymatic production.
Effect of Nutritional Supplements on Immune Function and Body Weight in Malnourished Adults
Authors: cheskin Lawrence J. , Margolick Joseph , Kahan Scott , Mitola Andrea H. , Poddar Kavita H. , Nilles Tricia , Kolge Sanjivani , Menendez Frederick , Ridoré Michelande , Wang Shing-Jung , Chou Jacob , Carlson Eve
Published: February 2011

In the United States, approximately 5% of the population is malnourished or has low body weight, which can adversely affect immune function. Malnutrition is more prevalent in older adults and is often a result of energy imbalance from various causes. Dietary supplementation to promote positive energy balance can reverse malnutrition, but has not been assessed for its effect on immune parameters. This 8-week clinical feeding trial evaluated the effect of a commercially available, high-protein, high-energy formula on body weight and immune parameters in 30 adult volunteers with body-mass indices (BMI) <21 kg/m2. After the intervention, participants gained a mean of 3.74 lbs and increased BMI by 0.58 kg/m2. The intervention improved lean body mass and limited body fat accumulation. However, no clinically significant improvements in immune measures were observed. These results support the use of high-protein, high-energy supplements in the treatment of underweight/malnutrition. Further investigation utilizing feeding studies of longer duration, and/or studying severely malnourished individuals may be needed to detect an effect on immune parameters of weight gain promoted by nutritional supplements.
Increased Serum Cu/Zn SOD in Individuals with Clinical Depression Normalizes after Zinc and Anti-oxidant Therapy
Authors: Russo A.J.
Published: February 2011

Aim

To assess serum Cu/Zn SOD (Superoxide Dismutase) concentration in individuals with clinical depression.

Subjects and Methods

Serum from 36 individuals diagnosed with clinical depression and 18 healthy controls were tested for Cu/Zn SOD serum concentration using ELISAs.

Results

Serum Cu/Zn SOD levels of depressed individuals (both with and without secondary anxiety) were significantly higher than age and gender similar controls. We also found that, post anti-oxidant therapy, Cu/Zn SOD levels normalized to the level of normal healthy controls.

Discussion

These results suggest an association between Cu/Zn SOD serum levels and clinical depression.
The Role of Nutrition in Sickle Cell Disease
Authors: Hyacinth H.I. , Gee B.E. , Hibbert J.M.
Published: February 2011

Finding a widely available cure for sickle cell anemia (HbSS) still remains a challenge one hundred years after its discovery as a genetically inherited disease. However, growing interest in the nutritional problems of the disease has created a body of literature from researchers seeking nutritional alternatives as a means of decreasing morbidity and improving quality of life among HbSS patients. This review demonstrates that over the past 30 years the role of protein/energy deficiency in HbSS has been more clearly defined via direct measurements, leading to the concept of a relative shortage of nutrients for growth and development, despite apparently adequate dietary intakes. Although there is still a paucity of data supporting the efficacy of macronutrient supplementation, it is becoming clearer that recommended dietary allowances (RDAs) for the general population are insufficient for the sickle cell patient. A similar shortage is likely to be true for micronutrient deficiencies, including recent findings of vitamin D deficiency that may be associated with incomplete ossification and bone disease, which are well known complications of HbSS disease. We conclude that there is need for more effort and resources to be dedicated to research (including supplementation studies of larger sample size) aimed at establishing specific RDAs for HbSS patients, much like the specific RDAs developed for pregnancy and growth within the general population.
Decreased Serum Hepatocyte Growth Factor (HGF) in Individuals with Anxiety Increases after Zinc Therapy
Authors: Russo A.J.
Published: February 2011

Aim

To assess serum Hepatocyte Growth Factor (HGF) levels in individuals with anxiety and to test the hypothesis that there is a relationship between HGF levels and zinc therapy.

Subjects and Methods

Serum from 19 individuals with anxiety and 19 controls were tested for serum HGF using ELISAs. HGF serum concentration in individuals with anxiety before zinc and anti-oxidant therapy was compared to levels after therapy. Zinc and copper levels in anxiety patients, pre and post therapy, were also measured and compared.

Results

Individuals with anxiety had significantly lower serum levels of HGF compared to controls ( P = 0.0005). HGF concentration rose significantly (normalized) after zinc therapy ( P = 0.04) and zinc levels increased significantly in these same patients ( P = 0.0002).

Discussion

These results suggest an association between HGF serum levels and individuals with anxiety and demonstrate that zinc therapy is associated with increasing HGF levels.
Decreased Serum Hepatocyte Growth Factor (HGF) in Individuals with Bipolar Disorder Normalizes after Zinc and Anti-oxidant Therapy
Authors: Russo A.J.
Published: February 2011

Aim

To assess serum HGF concentration in individuals with bipolar disorder and investigate the efficacy of zinc therapy on these levels.

Subjects and Methods

Serum from 35 individuals diagnosed with bipolar disorder and 19 age and gender similar controls were tested for HGF concentration using ELISAs, and copper and zinc plasma levels using inductively-coupled plasma-mass spectrometry.

Results

HGF serum levels of individuals with bipolar disorder were significantly lower than age and gender similar controls ( P = 0.0021). HGF serum concentration was significantly lower in Bipolar patients pre-therapy ( P = 0.0009) and HGF levels normalized post-therapy. Zinc levels in these same individuals also normalized ( P = 0.0046) and patient's perceived severity of Bipolar symptoms significantly decreased after therapy ( P = 0.0003). We also found a significant direct correlation between Zinc and HGF serum concentration in the bipolar patients ( P = 0.04).

Discussion

These results suggest an association between low HGF levels and bipolar disorder and also demonstrate that zinc therapy may be associated with the normalization of HGF levels and decrease in severity of disease.
Spectral Domain OCT Documented Resolution of Pseudophakic Cystoid Macular Edema after Intravitreal Triamcinolone
Authors: Murthy Ravi K , Chalam Kakarla V.
Published: February 2011

Cystoid macular edema (CME) is an important cause of visual loss after cataract surgery. Treatment is usually with topical anti-inflammatory agents, with anti-vascular endothelial growth factor agents and steroids used intravitreally in resistant cases. Even though time-domain Stratus OCT can quantify the macular thickness, it cannot prognosticate visual outcomes due to the poor resolution of images, especially the outer segment-inner segment junction. Spectral-domain OCT (SD-OCT) by its ability to acquire large number of images in a short span of time provides high resolution cross-sectional images of the retina, which not only highlights the underlying pathological changes, but in addition can prognosticate visual recovery. We describe pre and post SD-OCT features of a case of refractory CME who was treated with intravitreal triamcinolone actetonide.
Gas Exchange during Lung Perfusion/Ventilation during Cardiopulmonary Bypass: Preliminary Results of a Pilot Study
Authors: Macedo Francisco Igor B. , Carvalho Enisa M. , Gologorsky Edward , Barron Michael , Hassan Mohammed , Salerno Tomas A
Published: February 2011

Lung perfusion/ventilation was introduced as a means to minimize cardiopulmonary (CPB)-related pulmonary ischemic injury. Current results in the literature are divergent, and the role of gas exchange during lung perfusion/ventilation during CPB, remains undefined. This report details a) the technique of continuous lung perfusion/ventilation during CPB, b) provides initial observations, and c) discusses gas exchange during CPB.
Mass Transport/Diffusion and Surface Reaction Process with Lattice Boltzmann
Authors: De Prisco Giuseppe , Shan Xiaowen
Published: February 2011

Multi-component flow with chemical reactions is a common problem in different industrial applications: the mixing chamber of a reaction injection molding (RIM) machine; the dynamics of diesel soot particles interacting with a porous-ceramic particulate filter; reactive transport in porous media; bio-chemical processes involving enzyme-catalyzed kinetics. In all these cases, mass diffusion/convection and wall or volume chemical interactions among components play an important role. In the present paper we underline the importance of diffusion/convection/reaction mechanisms in bio-chemical processes using the Lattice Boltzmann (LB) technique. The bio-application where we studied diffusion/convection/reaction mechanisms is the quorum-sensing pathway for the bio-synthesis of the AI-2, a molecule that allows the bacteria to launch a coordinated attack on a host immune system (see [9,10] for more details of the bio-application). The overall goal is to create a micro-device to screen potential drugs that inhibit AI-2 bio-synthesis. The Michaelis-Menten saturation kinetic model is implemented at the reactive surface and the results are shown in terms of two dimensionless numbers: Damkohler (Da) and Peclet (Pe) number. For high Pe number a small conversion of reactants into products is obtained at the reactive surface, but the overall flux of products is high; moreover, a fast saturation of the conversion of reactants to products is obtained for high Da numbers. The trade-off for setting the Pe and Da numbers depends on the specific application and the technologies used in the micro-device (e.g., sensitivity of the detector, cost of reactants).
Rotational Slip Flow in Coaxial Cylinders by the Finite-Difference Lattice Boltzmann Methods
Authors: Watari Minoru
Published: February 2011

Recent studies on applications of the lattice Boltzmann method (LBM) and the finite-difference lattice Boltzmann method (FDLBM) to velocity slip simulations are mostly on one-dimensional (1D) problems such as a shear flow between parallel plates. Applications to a 2D problem may raise new issues. The author performed numerical simulations of rotational slip flow in coaxial cylinders as an example of 2D problem. Two types of 2D models were used. The first were multi-speed FDLBM models proposed by the author. The second was a standard LBM, the D2Q9 model. The simulations were performed applying a finite difference scheme to both the models. The study had two objectives. The first was to investigate the accuracies of LBM and FDLBM on applications to rotational slip flow. The second was to obtain an experience on application of the cylindrical coordinate system. The FDLBM model with 8 directions and the D2Q9 model showed an anisotropic flow pattern when the relaxation time constant or the Knudsen number was large. The FDLBM model with 24 directions showed accurate results even at large Knudsen numbers.
Immersed Boundary-Lattice Boltzmann Coupling Scheme for Fluid-Structure Interaction with Flexible Boundary
Authors: Cheng Yongguang , Zhang Hui , Liu Chang
Published: February 2011

Coupling the immersed boundary (IB) method and the lattice Boltzmann (LB) method might be a promising approach to simulate fluid-structure interaction (FSI) problems with flexible structures and complex boundaries, because the former is a general simulation method for FSIs in biological systems, the latter is an efficient scheme for fluid flow simulations, and both of them work on regular Cartesian grids. In this paper an IB-LB coupling scheme is proposed and its feasibility is verified. The scheme is suitable for FSI problems concerning rapid flexible boundary motion and a large pressure gradient across the boundary. We first analyze the respective concepts, formulae and advantages of the IB and LB methods, and then explain the coupling strategy and detailed implementation procedures. To verify the effectiveness and accuracy, FSI problems arising from the relaxation of a distorted balloon immersed in a viscous fluid, an unsteady wake flow caused by an impulsively started circular cylinder at Reynolds number 9500, and an unsteady vortex shedding flow past a suddenly started rotating circular cylinder at Reynolds number 1000 are simulated. The first example is a benchmark case for flexible boundary FSI with a large pressure gradient across the boundary, the second is a fixed complex boundary problem, and the third is a typical moving boundary example. The results are in good agreement with the analytical and existing numerical data. It is shown that the proposed scheme is capable of modeling flexible boundary and complex boundary problems at a second-order spatial convergence; the volume leakage defect of the conventional IB method has been remedied by using a new method of introducing the unsteady and non-uniform external force; and the LB method makes the IB method simulation simpler and more efficient.
Comparison of Two Advection-Diffusion Methods for Tephra Transport in Volcanic Eruptions
Authors: Tsunematsu Kae , Chopard Bastien , Falcone Jean-Luc , Bonadonna Costanza
Published: February 2011

In order to model the dispersal of volcanic particles in the atmosphere and their deposition on the ground, one has to simulate an advection-diffusion-sedimentation process on a large spatial area. Here we compare a Lattice Boltzmann and a Cellular Automata approach. Our results show that for high Peclet regimes, the cellular automata model produce results that are as accurate as the lattice Boltzmann model and is computationally more effective.
Lucas on the Relationship between Theory and Ideology
Authors: De Vroey Michel
Published: February 2011

This paper concerns a neglected aspect of Lucas’s work: his methodological writings, published and unpublished. Particular attention is paid to his views on the relationship between theory and ideology. I start by setting out Lucas’s non-standard conception of theory: to him, a theory and a model are the same thing. I also explore the different facets and implications of this conception. In the next two sections, I debate whether Lucas adheres to two methodological principles that I dub the ‘non-interference’ precept (the proposition that ideological viewpoints should not influence theory), and the ‘non-exploitation’ precept (that the models’ conclusions should not be transposed into policy recommendations, in so far as these conclusions are built into the models’ premises). The last part of the paper contains my assessment of Lucas’s ideas. First, I bring out the extent to which Lucas departs from the view held by most specialized methodologists. Second, I wonder whether the new classical revolution resulted from a political agenda. Third and finally, I claim that the tensions characterizing Lucas’s conception of theory follow from his having one foot in the neo- Walrasian and the other in the Marshallian-Friedmanian universe.
The CO2 release and Oxygen uptake from Fossil Fuel Emission Estimate (COFFEE) dataset: effects from varying oxidative ratios
Authors: Steinbach J. , Gerbig C. , Rödenbeck C. , Karstens U. , Minejima C. , Mukai H.
Published: February 2011

Abstract. We present a global dataset of CO2 emissions and O2 uptake associated with the combustion of different fossil fuel types. To derive spatial and temporal patterns of oxygen uptake, we combined high-resolution CO2 emissions from the EDGAR (Emission Database for Global Atmospheric Research) inventory with country level information on oxidative ratios, based on fossil fuel consumption data from the UN energy statistics database. The results are hourly global maps with a spatial resolution of 1° × 1° for the years 1996–2008. The potential influence of spatial patterns and temporal trends in the resulting O2/CO2 emission ratios on the atmospheric oxygen signal is examined for different stations in the global measurement network, using model simulations from the global TM3 and the regional REMO transport model. For the station Hateruma Island (Japan, 24° 03' N, 123° 48' E), the simulated results are also compared to observations. In addition, the possibility of signals caused by variations in fuel use to be mistaken for oceanic signals is investigated using a global APO inversion.
Simultaneous retrieval of aerosol and cloud properties during the MILAGRO field campaign
Authors: Knobelspiesse K. , Cairns B. , Redemann J. , Bergstrom R. W. , Stohl A.
Published: February 2011

Abstract. Estimation of Direct Climate Forcing (DCF) due to aerosols in cloudy areas has historically been a difficult task, mainly because of a lack of appropriate measurements. The Aerosol Polarimetry Sensor (APS), on the upcoming NASA Glory mission, has the potential to retrieve both cloud and aerosol properties because of its polarimetric, multiple view angle, and multi spectral observations. The APS airborne prototype is the Research Scanning Polarimeter (RSP), which has similar characteristics and can be used to demonstrate APS capabilities. In the spring of 2006, the RSP was deployed on an aircraft based in Veracruz, Mexico, as part of the Megacity Initiative: Local and Global Research Observations (MILAGRO) field campaign. On March 13th, the RSP over flew an aerosol layer lofted above a low altitude marine stratocumulus cloud close to shore in the Gulf of Mexico. We investigate the feasibility of retrieving aerosol properties over clouds using these data. Our approach is to first determine cloud droplet size distribution using the angular location of the cloud bow and other features in the polarized reflectance. The selected cloud was then used in a multiple scattering radiative transfer model optimization to determine the aerosol optical properties and fine tune the cloud size distribution. In this scene, we were able to retrieve aerosol optical depth, the fine mode aerosol size distribution and the cloud droplet size distribution to a degree of accuracy required for climate modeling. This required assumptions about the aerosol vertical distribution and the optical properties of the coarse aerosol size mode. A sensitivity study was also performed to place this case study in the context of the potential for future systematic APS observations of this kind, which found that the aerosol complex refractive index can also be observed accurately if the aerosol optical depth is larger than roughly 0.8 at a wavelength of 0.555 μm.
Seasonal impact of natural and anthropogenic emissions on the highest glacier of the Eastern European Alps
Authors: Gabrieli J. , Carturan L. , Gabrielli P. , Turetta C. , Kehrwald N. , Cozzi G. , Staffler H. , Dinale R. , Seppi R. , dalla Fontana G. , Thompson L. , Barbante C.
Published: February 2011

Abstract. In June 2009, we conducted the first extensive glaciological survey of Alto dell'Ortles, the uppermost glacier of Mt. Ortles which at 3905 meters above sea level (m a.s.l.) is the highest summit of the Eastern European Alps. We analyzed snow samples collected from a 4.5 m snow-pit at 3830 m a.s.l. Here, we present a comprehensive data set including a large suite of trace elements and ionic compounds that comprise the atmospheric depositions over the past few years. Trace element concentrations measured in snow samples are extremely low with mean concentrations at pg g−1 level. Only Al and Fe present median values of 1.8 and 3.3 ng g−1, with maximum concentrations of 21 and 25 ng g−1. The median EFc values for Be, Rb, Sr, Ba, U, Li, Al, Ca, Cr, Mn, Fe, Co, Ga and V are lower than 10 suggesting that these elements originated mainly from soil and mineral aerosol. EFc higher than 100 are reported for Zn (118), Ag (135), Bi (185), Sb (401) and Cd (514), demonstrating the predominance of non-crustal depositions and suggesting an anthropogenic origin. Our data show that the physical stratigraphy and the chemical signals of several species were well preserved in the uppermost snow of the Alto dell'Ortles glacier. A clear seasonality emerges from the data as the summer snow is more affected by anthropogenic and marine contributions while the winter aerosol flux is dominated by crustal sources. For trace elements, the largest mean EFc seasonal variations are displayed by V (with a factor of 3.8), Sb (3.3), Cu (3.3), Pb (2.9), Bi (2.8), Cd (2.1), Zn (1.9), Ni (1.8), Ag (1.8), As (1.7) and Co (1.6). The chemical data are also discussed in light of the atmospheric stability and back-trajectories analyses in order to explain the observed seasonal variability and how human activities impact the high altitude environment in the Eastern Alps. The origin and behavior of air masses as inferred from the evaluation of 48-h back-trajectories show significant seasonal differences. However, the large changes in trace elements concentrations seem to be more related to the vertical structure of the troposphere at a regional scale rather than the synoptic weather patterns.
Hygroscopic properties of the ambient aerosol in southern Sweden – a two year study
Authors: Fors E. O. , Swietlicki E. , Svenningsson B. , Kristensson A. , Frank G. P. , Sporre M.
Published: February 2011

Abstract. The hygroscopic growth of the atmospheric aerosol is a critical parameter for quantifying the anthropogenic radiative forcing. Until now, there has been a lack of long term measurements due to limitations in instrumental techniques. In this work, for the first time the seasonal variation of the hygroscopic properties of a continental background aerosol has been described, based on more than two years of continuous measurements. In addition to this, the diurnal variation of the hygroscopic growth has been investigated, as well as the seasonal variation in CCN concentration. These physical properties of the aerosol have been measured with a Hygroscopic Tandem Differential Mobility Analyzer (H-TDMA), a Differential Mobility Particle Sizer (DMPS), and a Cloud Condensation Nuclei Counter (CCNC). The results show that smaller particles are generally less hygroscopic than larger ones, and that there is a clear difference in the hygroscopic properties between the Aitken and the accumulation mode. A seasonal cycle was found for all particle sizes. In general, the average hygroscopic growth is lower during wintertime, due to an increase in the relative abundance of less hygroscopic or hydrophobic particles. Monthly averages showed that the hygroscopic growth factors of the two dominating hygroscopic modes (one barely hygroscopic and one more hygroscopic) were relatively stable. The hygroscopic growth additionally showed a diurnal cycle, with higher growth factors during day time. CCN predictions based on H-TDMA data underpredicted the activated CCN concentration with 7% for 1% water supersaturation (s). The underprediction increases with decreasing $s$, most likely due to a combination of measurement and modeling uncertainties. It was found that although the aerosol is often externally mixed, recalculating to an internal mixture with respect to hygroscopicity did not change CCN parameterizations significantly.
Assessment of BSRN radiation records for the computation of monthly means
Authors: Roesch A. , Wild M. , Ohmura A. , Dutton E. G. , Long C. N. , Zhang T.
Published: February 2011

Abstract. The integrity of the Baseline Surface Radiation Network (BSRN) radiation monthly averages are assessed by investigating the impact on monthly means due to the frequency of data gaps caused by missing or discarded high time resolution data. The monthly statistics, especially means, are considered to be important and useful values for climate research, model performance evaluations and for assessing the quality of satellite (time- and space-averaged) data products. The study investigates the spread in different algorithms that have been applied for the computation of monthly means from 1-min values. The paper reveals that the computation of monthly means from 1-min observations distinctly depends on the method utilized to account for the missing data. The intra-method difference generally increases with an increasing fraction of missing data. We found that a substantial fraction of the radiation fluxes observed at BSRN sites is either missing or flagged as questionable. The percentage of missing data is 4.4%, 13.0%, and 6.5% for global radiation, direct shortwave radiation, and downwelling longwave radiation, respectively. Most flagged data in the shortwave are due to nighttime instrumental noise and can reasonably be set to zero after correcting for thermal offsets in the daytime data. The study demonstrates that the handling of flagged data clearly impacts on monthly mean estimates obtained with different methods. We showed that the spread of monthly shortwave fluxes is generally clearly higher than for downwelling longwave radiation. Overall, BSRN observations provide sufficient accuracy and completeness for reliable estimates of monthly mean values. However, the value of future data could be further increased by reducing the frequency of data gaps and the number of outliers. It is shown that two independent methods for accounting for the diurnal and seasonal variations in the missing data permit consistent monthly means to within less than 1 W m−2 in most cases. The authors suggest using a standardized method for the computation of monthly means which addresses diurnal variations in the missing data in order to avoid a mismatch of future published monthly mean radiation fluxes from BSRN. The application of robust statistics would probably lead to less biased results for data records with frequent gaps and/or flagged data and outliers. The currently applied empirical methods should, therefore, be completed by the development of robust methods.
Magnetic curvature driven Rayleigh-Taylor instability revisited
Authors: Pokhotelov O. A. , Onishchenko O. G.
Published: February 2011

Abstract. The problem of incomplete finite ion Larmor radius (FLR) stabilization of the magnetic curvature driven Rayleigh-Taylor instability (RTI) in low beta plasma with homogeneous ion temperature is investigated. For this purpose a model hydrodynamic description of nonlinear flute waves with arbitrary spatial scales compared to the ion Larmor radius is developed. It is shown that the RTI is not stabilized by FLR effects in a plasma with cold electrons when the ratio of characteristic spatial scale of the plasma inhomogeneity to local effective radius of curvature of the magnetic field lines is larger than 1/4. The crucial role in the absence of the complete FLR stabilization plays the contribution of the compressibility of the polarization part of the ion velocity.
Effects of cloudiness on carbon dioxide exchange over an irrigated maize cropland in northwestern China
Authors: Zhang B. C. , Cao J. J. , Bai Y. F. , Yang S. J. , Hu L. , Ning Z. G.
Published: February 2011

Abstract. Clouds can strongly influence solar radiation and affects other microclimatic factors (such as air temperature and vapour pressure deficit), and those changed environmental conditions may exert strong effects on carbon exchange between terrestrial ecosystems and the atmosphere. In this study, we analyzed how canopy photosynthesis and ecosystem respiration respond to changes in cloudy conditions, based on two years of eddy-covariance and meteorological data from an irrigated maize cropland in Yingke oasis of northwestern China. The results showed that net carbon uptake was more negative under cloudy than under clear conditions, it indicates that net carbon uptake increased under cloudy days. The rate of ecosystem respiration (Re) decreased under cloudy conditions due to decreased air temperature. However, photosynthesis was suppressed by the decreasing air temperature and vapour pressure deficit (VPD) under cloudy skies. Thus, the enhancement of net carbon uptake under cloudy skies mainly contributed from increasing photosynthesis with diffuse radiation. Those results improve our understanding of the effects of cloud cover on carbon exchange process in maize (C4) cropland, and improve our understanding of the driver improving net carbon uptake under cloudy conditions.
Impact of maximum borehole depths on inverted temperature histories in borehole paleoclimatology
Authors: Beltrami H. , Smerdon J. E. , Matharoo G. S. , Nickerson N.
Published: February 2011

Abstract. A quantitative assessment is presented for the impact of the maximum depth of a temperature-depth profile on the estimate of the climatic transient and the resultant ground surface temperature (GST) reconstruction used in borehole paleoclimatology. The depth of the profile is important because the downwelling climatic signal must be separated from the quasi-steady state thermal regime established by the energy in the Earth's interior. This component of the signal is estimated as a linear increase in temperature with depth from the lower section of a borehole temperature profile, which is assumed to be unperturbed by recent changes in climate at the surface. The validity of this assumption is dependent on both the subsurface thermophysical properties and the character of the downwelling climatic signal. Such uncertainties can significantly impact the determination of the quasi-steady state thermal regime, and consequently the magnitude of the temperature anomaly interpreted as a climatic signal. The quantitative effects and uncertainties that arise from the analysis of temperature-depth profiles of different depths are presented. Results demonstrate that widely different GST histories can be derived from a single temperature profile truncated at different depths. Borehole temperature measurements approaching 500–600 m depths are shown to provide the most robust GST reconstructions spanning 500 to 1000 ybp. It is further shown that the bias introduced by a temperature profile of depths shallower than 500–600 m remains even if the time span of the reconstruction target is shortened.
Bayesian inverse modelling of in situ soil water dynamics: using prior information about the soil hydraulic properties
Authors: Scharnagl B. , Vrugt J. A. , Vereecken H. , Herbst M.
Published: February 2011

Abstract. In situ observations of soil water state variables under natural boundary conditions are often used to estimate field-scale soil hydraulic properties. However, many contributions to the soil hydrological literature have demonstrated that the information content of such data is insufficient to reliably estimate all the soil hydraulic parameters. In this case study, we tested whether prior information about the soil hydraulic properties could help improve the identifiability of the van Genuchten-Mualem (VGM) parameters. Three different prior distributions with increasing complexity were formulated using the ROSETTA pedotransfer function (PTF) with input data that constitutes basic soil information and is readily available in most vadose zone studies. The inverse problem was posed in a formal Bayesian framework and solved using Markov chain Monte Carlo (MCMC) simulation with the DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm. Synthetic and real-world soil water content data were used to illustrate our approach. The results of this study corroborate and explicate findings previously reported in the literature. Indeed, soil water content data alone contained insufficient information to reasonably constrain all VGM parameters. The identifiability of these soil hydraulic parameters was substantially improved when an informative prior distribution was used with detailed knowledge of the correlation structure among the respective VGM parameters. A biased prior did not distort the results, which inspires confidence in the robustness and effectiveness of the presented method. The Bayesian framework presented in this study can be applied to a wide range of vadose zone studies and provides a blueprint for the use of prior information in inverse modelling of soil hydraulic properties at various spatial scales.
An ocean modelling and assimilation guide to using GOCE geoid products
Authors: Haines K. , Johannessen J. A. , Knudsen P. , Lea D. , Rio M.-H. , Bertino L. , Davidson F. , Hernandez F.
Published: February 2011

Abstract. We review the procedures and challenges that must be considered when using geoid data derived from the Gravity and steady-state Ocean Circulation Explorer (GOCE) mission in order to constrain the circulation and water mass representation in an ocean general circulation model. It covers the combination of the geoid information with time-mean sea level information derived from satellite altimeter data, to construct a mean dynamic topography (MDT), and considers how this complements the time-varying sea level anomaly, also available from the satellite altimeter. We particularly consider the compatibility of these different fields in their spatial scale content, their temporal representation, and in their error covariances. These considerations are very important when the resulting data are to be used to estimate ocean circulation and its corresponding errors. We describe the further steps needed for assimilating the resulting dynamic topography information into an ocean circulation model using three different operational forecasting and data assimilation systems. We look at methods used for assimilating altimeter anomaly data in the absence of a suitable geoid, and then discuss different approaches which have been tried for assimilating the additional geoid information. We review the problems that have been encountered and the lessons learned in order the help future users. Finally we present some results from the use of GRACE geoid information in the operational oceanography community and discuss the future potential gains that may be obtained from a new GOCE geoid.
Multiple Bilateral Ocular Metastases from Malignant Melanoma Associated with Blue Nevi
Authors: Kelmenson Amy T. , Grover Sandeep
Published: February 2011

Purpose

Malignant melanoma associated with a blue nevus is a rare diagnosis. Additionally, only a handful of cases of malignant melanoma associated with blue nevi involving the ocular structures have been reported. We report a probable case of malignant melanoma associated with a blue nevus with metastasis to multiple bilateral ocular structures.

Methods

Observational case report.

Results

We report a case of a 27-year-old man with lymph node biopsy-proven malignant melanoma as well as a separate skin biopsy of a blue nevus, who developed multiple bilateral pigmented ocular lesions on the sclera, iris, trabecular meshwork, and choroid.

Conclusions

Although ocular histopathologic evidence could not be obtained, our case likely represents a case of explosive widespread metastasis probably originating from a blue nevus of unknown location, which involved both eyes and adnexae.
Bilateral (opercular and paracentral lobular) polymicrogyria and neurofibromatosis type 1
Authors: Ruggieri Martino , Mastrangelo Mario , Spalice Alberto , Mariani Rosanna , Torrente Isabella , Polizzi Agata , Bottillo Irene , Di Biase Claudio , Iannetti Paola
Published: February 2011

Anecdotal cases of polymicrogyria (PMG; a malformation of cortical development consisting of an excessive number of small gyri with abnormal lamination) in patients with neurofibromatosis type 1 (NF1) have been described; however, the cases were unilateral and had negative NF1 genetic testing. We describe an 11‐year‐old girl with NF1 manifesting as a complex epileptic syndrome, including partial seizures secondarily generalized and status epilepticus, who had in association, bilateral, asymmetrical (opercular and paracentral lobular) PMG. She had a 1‐bp deletion (c.1862delC) in exon 12b of the NF1 gene. It is notable that, given the key role played by the NF1 gene product, neurofibromin, in normal brain development, and the relatively high frequency of other brain findings in NF1, there are not more NF1 cases with brain malformations manifesting as PMG. © 2011 Wiley‐Liss, Inc.
Clinical phenotypes of a juvenile sibling pair carrying the fragile X premutation
Authors: Basuta Kirin , Narcisa Vivien , Chavez Alyssa , Kumar Madhur , Gane Louise , Hagerman Randi , Tassone Flora
Published: February 2011

Individuals with alleles containing 55–200 CGG repeats in the fragile X mental retardation (FMR1) gene are premutation carriers. The premutation allele has been shown to lead to a number of types of clinical involvement, including shyness, anxiety, social deficits, attention deficit hyperactivity disorder (ADHD), and executive function deficits. Some of these problems could be due to mild deficits of the fragile X protein (FMRP) and a possible developmental effect of the elevated FMR1 mRNA observed in carriers. In addition, two abnormal phenotypes specific to the premutation have been described. Primary ovarian insufficiency (FXPOI), defined by cessation of menses prior to age 40, occurs in 20% of females with the premutation. The other phenotype, fragile X‐associated tremor/ataxia syndrome (FXTAS), affects some older adult premutation carriers. Premutation females typically have one expanded allele (≥55 CGG repeats) and one normal allele (≤54 CGG repeats). This study describes the cognitive, behavioral, and molecular profile of a female with two alleles in the premutation range (60 and 67 CGG repeats) in comparison to her brother with a similar premutation size (65 CGG repeats). Both exhibited high IQ scores, anxiety, and some physical features associated with fragile X syndrome. This comparison allows us to examine the effect of the premutation in this male–female pair while controlling for environmental and background genetic factors. © 2011 Wiley‐Liss, Inc.
The difficult nosology of blepharophimosis–mental retardation syndromes: Report on two siblings
Authors: Dentici Maria Lisa , Mingarelli Rita , Dallapiccola Bruno
Published: February 2011

Blepharophimosis–mental retardation syndromes (BMRS) include a group of clinically and etiologically heterogeneous conditions, which can occur as isolated features or as part of distinct disorders displaying multiple congenital anomalies. We report on two siblings, a 6‐year‐old girl and an 18‐month‐old male, presenting with overlapping clinical findings. Major characteristics included facial dysmorphisms with upward slanted palpebral fissures, blepharophimosis, telecanthus, hypertelorism, posteriorly rotated and abnormal ears, and micrognathia. Ectodermal abnormalities consisted of fine hair, sparse eyebrows, and thin skin. Both patients had feeding difficulties with gastro‐esophageal reflux and growth retardation. Psychomotor skills were severely delayed with no verbal capacity. The male sib also displayed low growth hormone (GH) levels, while the older sister had low cholesterol and mildly elevated TSH levels. Numerous metabolic/genetic investigations, including cholesterol precursors, dosage, and high‐resolution array‐CGH, were negative. BMR syndromes, including Dubowitz syndrome, Marden–Walker syndrome, Ohdo/Ohdo‐like syndromes, and the cholesterol storage disorders were considered. We concluded that these two patients are affected by a possible autosomal recessive condition within the heterogeneous clinical spectrum of BMRS, fitting with the Young–Simpson syndrome subtype. © 2011 Wiley‐Liss, Inc.
A novel homozygous missense mutation (c.610G>A, p.Gly204Ser) in the WNT7A gene causes tetra‐amelia in two Saudi families
Authors: Eyaid Wafaa , Al‐Qattan Mohammad M. , Al Abdulkareem Ibrahim , Fetaini Nouf , Al Balwi Mohammed
Published: February 2011

Fuhrmann syndrome and Al‐Awadi/Raas‐Rothschild/Schinzel (AA/RRS) phocomelia syndrome are rare autosomal recessive inherited disorders characterized by aplastic/hypoplastic nails with ectopic dorsal palms, absence of humeri, hypoplastic ulnae, and bowed short radii with the elbow joints present, shown to result from missense mutations in WNT7A (p.Ala109Thr and p.Arg292Cys). Here, we describe three affected individuals belonging to two related Saudi Arabian families. All three have a similar phenotype characterized by pelvic dysplasia and truncated lower limbs compatible with the clinical diagnosis of AA/RRS. The upper limbs were more variable: one patient individual had complete amelia, whereas the others had variable limb malformations and all had absence of nails and the ventralization of the palms/digits. All affected individuals were homozygous for a mutation in exon 4 of WNT7A (c.610G>A) resulted in substitution of a highly conserved glycine to serine (p.Gly204Ser) within the Wnt signature motif [C‐K‐C‐H‐G‐V‐S‐G‐S‐C]. This report describes a third cases/family in the literature with variable phenotype of AA/RRS and Fuhrmann syndrome. Identification of this mutation further underlines the crucial involvement of WNT7A in the limb development. This novel missense homozygous mutation (p.Gly204Ser) in the WNT7A gene is a unique mutation in the degree of loss of function in the upper limb development which ranges from mild to complete absence of both upper limbs (amelia). Moreover, all three affected individuals had genitourinary anomalies, linking WNT7A function to genitourinary development. © 2011 Wiley‐Liss, Inc.
Ophthalmic findings in the Greek isolate of Cohen syndrome
Authors: Douzgou Sofia , Samples John Randall , Georgoudi Nelli , Petersen Michael Bjorn
Published: February 2011

A high frequency of the Cohen syndrome has been observed in a Greek island with 2,000 inhabitants and a high degree of inbreeding. All patients were homozygous for a COH1, exon 6–16 deletion suggesting a founder effect. We present the results of their first systematic ophthalmologic assessment. Myopia and chorioretinal atrophy were present in all patients of this cohort. Yet, in contrast to all groups previously reported, the majority presented with corneal changes, independently from age, gender, and family history. A pair of sisters, aged 11 and 15 years old, presented with bilateral keratoconus. More frequently (86%) than in any other ethnic group, Greek patients had cataracts that were bilateral and often graded as high as 3, even at a young age. As a whole, the ophthalmic phenotype of the Greek isolate of Cohen syndrome is characterized by the involvement of both the posterior and the anterior eye segment, bilaterally, in the majority of cases (93%). Greek Cohen patients that share a founder mutation are at a higher risk of developing blindness in respect to those of other ethnicities and genotypes. This study highlighted the need for pachymetry measurement as a means of surveillance and prediction of the visual impairment frequently observed. © 2011 Wiley‐Liss, Inc.
Hereditary hypophosphatemic rickets with hypercalciuria and nephrolithiasis—Identification of a novel SLC34A3/NaPi‐IIc mutation
Authors: Phulwani Priya , Bergwitz Clemens , Jaureguiberry Graciana , Rasoulpour Majjid , Estrada Elizabeth
Published: February 2011

Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is characterized by rickets, hyperphosphaturia, hypophosphatemia, elevated 1,25‐dihydroxyvitamin‐D, increased gastrointestinal calcium absorption and hypercalciuria. Serum calcium, 25‐hydroxyvitamin‐D and PTH levels are normal. Here we describe a boy with HHRH, nephrolithiasis, and compound heterozygosity for one previously described mutation (g.4225_50del) and a novel splice mutation (g.1226G>A) in SLC34A3, the gene encoding the renal sodium‐phosphate co‐transporter NaPi‐IIc. The patient's mother and grandmother are carriers of g.4225_50del, and both have a history of nephrolithiasis associated with hypercalciuria and elevated 1,25‐dihydroxyvitamin‐D. His three siblings (2–6 years old), who are also carriers of g.4225_50del, have hypercalciuria but so far their renal ultrasounds are normal. Thus, SLC34A3/NaPi‐IIc mutations appear to be associated with variable phenotypic changes at presentation, which can include recurrent nephrolithiasis. © 2011 Wiley‐Liss, Inc.
A girl with metopic synostosis and trisomy 13 mosaicism: Case report and review of the literature
Authors: Aypar Ebru , Yildirim M. Selman , Sert Ahmet , Ciftci Ilhan , Odabas Dursun
Published: February 2011

Trisomy 13, or Patau syndrome is a rare chromosomal disorder characterized by a triad of cleft lip and palate, postaxial polydactyly and microcephaly. Complete, partial, or mosaic forms of the disorder can occur. Mosaic trisomy 13 is very rare, it occurs in only 5% of all patients with trisomy 13 phenotype. Metopic synostosis (MS) is premature fusion of the metopic suture, which is part of the frontal suture. It results in a V‐shaped abnormality at the front of the skull. MS may occur in a syndromic or nonsyndromic form. We report on a 24‐day‐old girl with hypotonia, MS, trigonocephaly, capillary hemangioma, hypotelorism, upward slanting palpebral fissures, epicanthal folds, small nose with anteverted nares, high palate, ankyloglossia, long philtrum, low‐set ears, short neck, postaxial polydactyly of both hands and feet and congenital heart defect. Cytogenetic analysis demonstrated trisomy 13 mosaicism; 46,XX[58]/47,XX,+13[42]. Although MS has been previously reported in complete and partial forms of trisomy 13, it has not been reported in mosaic form of trisomy 13. Our report supports the evidence that trisomy 13 causes MS. It also emphasizes the need for cytogenetic investigations in patients presenting with MS and multiple congenital anomalies for providing accurate diagnosis, genetic counseling, and prenatal diagnosis. © 2011 Wiley‐Liss, Inc.