bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of neural network and support vector machine methods for Kp forecasting
Authors: Ji Eun‐Young , Moon Y.‐J. , Park Jongyeob , Lee Jin‐Yi , Lee D.‐H.
Published: August 2013

We have made a comparison of near‐real time Kp forecast models based on neural network (NN) and support vector machine (SVM) algorithms. For this, we consider four models as follows: (1) a NN model using solar wind data, (2) a SVM model using solar wind data, (3) a NN model using solar wind data and preliminary Kp values from ground‐based magnetometers, and (4) a SVM model using the same input data used in model 3. For the comparison, we estimate the correlation coefficients and the RMS errors, and the mean absolute errors between the observed Kp and the predicted one. As a result, we find that model 3 shows the best performance. The correlation coefficients, the RMS error, and the mean absolute error of model 3 are 0.93, 0.48, and 0.61, respectively. For the forecast evaluation of high magnetic activity occurrence for the four models, we present contingency tables and their statistical parameters such as probability of detection yes, false alarm ratio, bias, critical success index, and true skill statistic. From a comparison of these statistical parameters, we find that model 3 is superior to the other models for the forecasting of high magnetic activities (Kp ≥ 6).
A laboratory model for melting erosion of a magma chamber roof and the generation of a rhythmic layering
Authors: Shibano Yasuko , Sumita Ikuro , Namiki Atsuko
Published: August 2013

A hot magma chamber can ascend by melting the roof rock, a process which in turn affects the magma composition. The disaggregated mineral particles which consisted the roof rock will descend in the magma chamber to form a sedimentary cumulate. However, the fluid dynamics leading to the formation of the sediment, and how we can decipher them is unknown. Here we conducted a series of experiments modeling melting erosion of the roof with particle size consisting the roof rock as the parameter. We find that there is a critical particle size below which the melting erosion occurs rhythmically. Melting erosion stops because the disaggregated particles are suspended in the magma chamber and suppress the vertical heat transfer. The suspension then separates into an upper clear layer and a lower suspension layer. Eventually, the heated stratified layers become unstable. An overturn occurs, and melting erosion resumes. When the particles consist of two sizes such that at least one of them is smaller than the critical size, a rhythmic erosion occurs. Particles are sorted during each erosion period, and a size‐graded rhythmic layering is spontaneously generated. We estimate that rhythmic layering can be generated from melting erosion in a basaltic magma chamber when the grain size of the roof rock is ≤ 0.6 mm, assuming a vertical temperature difference of 10°C. We suggest that rhythmic roof melting coupled with particle settling is one possible mechanism for generating the rhythmic layering which is commonly observed in solidified magma chambers.
Crustal and uppermost mantle structure in the central U.S. encompassing the Midcontinent Rift
Authors: Shen Weisen , Ritzwoller Michael H. , Schulte‐Pelkum Vera
Published: August 2013

Rayleigh wave phase velocities across the western arm of the Midcontinent Rift (MCR) and surrounding regions are mapped by ambient noise (8–40 s) and earthquake tomography (25–80 s) applied to data from more than 120 Earthscope/USArray stations across the central U.S. Receiver functions also are computed for those stations using harmonic stripping. Joint Bayesian Monte Carlo inversion is applied to generate 3‐D posterior distributions of shear wave speeds (Vsv) in the crust and uppermost mantle to a depth of about 150 km, providing an overview of the seismic structure of the MCR and adjacent structures. Three major structural attributes are identified: (1) There is a high correlation between the long‐wavelength gravity field and shallow Vs structure, but the MCR gravity high is obscured by clastic sediments in the shallow crust. This is consistent with an upper crustal origin to the MCR gravity anomaly as well as other anomalies in the region. (2) Thick crust (>47 km) underlies the MCR, but there is a gradient Moho in the northern part of the rift and a sharp Moho in the south. Thickened crust beneath the MCR is evidence for postrifting compression with pure‐shear deformation along the entire rift; along‐rift differences in lower crustal structure may signify magmatic underplating in the northern rift. (3) Crustal shear wave speeds vary across the Precambrian sutures (e.g., Great Lakes Tectonic Zone, Spirit Lakes Tectonic Zone). This reveals the importance of Precambrian sutures in the subsequent tectonic evolution of the central U.S.
The Separate Physics and Dynamics Experiment (SPADE) framework for determining resolution awareness: A case study of microphysics
Authors: Gustafson William I. , Ma Po‐Lun , Xiao Heng , Singh Balwinder , Rasch Philip J. , Fast Jerome D.
Published: August 2013

Multiresolution dynamical cores for weather and climate modeling are pushing the atmospheric community toward developing scale aware or, more specifically, resolution aware parameterizations that function properly across a range of grid spacings. Determining resolution dependence of specific model parameterizations is difficult due to resolution dependencies in many model components. This study presents the Separate Physics and Dynamics Experiment (SPADE) framework for isolating resolution dependent behavior of specific parameterizations without conflating resolution dependencies from other portions of the model. To demonstrate SPADE, the resolution dependence of the Morrison microphysics, from the Weather Research and Forecasting model, and the Morrison‐Gettelman microphysics, from the Community Atmosphere Model, are compared for grid spacings spanning the cloud modeling gray zone. It is shown that the Morrison scheme has stronger resolution dependence than Morrison‐Gettelman, and the partial cloud fraction capability of Morrison‐Gettelman is not the primary reason for this difference.
Characteristics of lightning flashes with exceptional illuminated areas, durations, and optical powers and surrounding storm properties in the tropics and inner subtropics
Authors: Peterson Michael , Liu Chuntao
Published: August 2013

Twelve years (1998–2009) of Lightning Imaging Sensor (LIS) observations are used to characterize lightning flashes by illuminated area, duration, and optical power, particularly for exceptional flashes defined as those above the 90th percentile of each parameter. Statistics of lightning are summarized over land, ocean, and coastal regions of the Tropical Rainfall Measuring Mission satellite's domain extending from 36°S to 36°N. The degree to which optical flash parameters are interrelated is discussed, as well as coincident environmental properties and the overall characteristics of parent thunderstorms. LIS flashes over the southern United States are also collocated to National Lightning Detection Network (NLDN) observations, and relationships between LIS optical flash properties and corresponding NLDN strengths are discussed. Daytime (nighttime) oceanic flashes are shown to be 31.7% (39.4%) larger and 55.2% (75.1%) brighter in terms of maximum event pixel radiance. At the same time, daytime (nighttime) coastal flashes have 22.1% (7.8%) longer durations than flashes over land and 15.6% (11.4%) longer durations than oceanic flashes. Particularly, large and bright flashes observed by LIS are typically centered in weak storm regions, but thunderstorms with exceptional flashes are, themselves, more intense overall than those with only small and dim flashes. Diurnally, the top 10% brightest lightning flashes peak about 2 h earlier than the top 10% largest and long‐lasting flashes over land, implying that lightning flash characteristics vary with the life cycle of thunderstorms. Larger and more radiant flashes are also shown to be associated with stronger NLDN flashes of positive and negative polarity.
Application of wavelet empirical orthogonal function analysis to investigate the nonstationary character of Ethiopian rainfall and its teleconnection to nonstationary global sea surface temperature variations for 1900–1998
Authors: Elsanabary Mohamed Helmy , Gan Thian Yew , Mwale Davison
Published: August 2013

This study employed the wavelet empirical orthogonal function (WEOF) analysis to analyse the nonstationary variability of rainfall in Ethiopia and global sea surface temperature (SST) for 1900–1998. The study found that the nonstationary variations of both the June to September (JJAS) and February to May (FMAM) Ethiopian rainfall can be delineated into three zones: western half of Ethiopia north of the Great Rift Valley (GRV), southern Ethiopia south of the GRV and the GRV from southwestern Ethiopia to the Afar Triangle. The leading wavelet principal component (WPC) signals showed that Ethiopian rainfall had been in stagnation for most of 1900–1998, with major droughts in the 1940s and 1980s. The dominant frequencies of Ethiopian rainfall ranged between 2 and 8 years. In western Ethiopia, the 2–4‐year rainfall frequencies dominated the rainfall variation, but their trends are modulated by 5–7‐year frequencies, whereas in the Afar Triangle, the 5–7‐year frequencies were dominant. Between 1900 and 1998, the Afar Triangle region experienced decreasing rainfall for 60 years (1900–1960). The seasonal global SST revealed that regardless of what time of the year, the strongest contributions to global SST variations occur in the Antarctic Ocean, the El Niño region of South America and in the southwestern Pacific Ocean, followed by the Atlantic and the Indian Oceans. Further, this study also shows annual migrations of SST variations in the El Niño region, the Antarctic and the Atlantic Oceans. The leading SST signal variations show that SST warming started in the Atlantic and Indian Oceans, from 1950 to 1975, and spread to the Antarctic Ocean between 1960 and 1990, which probably contributed to the melting of sea ice. Teleconnections between WPC1 of Ethiopian rainfall and SST scale‐averaged wavelet power were found for the El Niño region and northern Atlantic, west of the Sahara desert.
Observed surface wind speed in the Tibetan Plateau since 1980 and its physical causes
Authors: You Qinglong , Fraedrich Klaus , Min Jinzhong , Kang Shichang , Zhu Xiuhua , Pepin Nick , Zhang Ling
Published: August 2013

Climate warming on the Tibetan Plateau (TP) potentially influences many climate parameters other than temperature including wind speed, cloudiness and precipitation. Temporal trends of surface wind speed at 71 stations above 2000 m above sea level in the TP are examined during 1980–2005. To uncover causes of observed trends in wind speed, relationships with surface temperature, a TP index and sunshine duration are also analysed. The TP index is calculated as the accumulated 500 hPa geopotential height above 5000 m over the region of 30°N–40°N, 75°E–105°E from NCEP/NCAR reanalysis. The annual mean wind speed patterns during 1980–2005 are similar to those in different seasons, with higher wind speeds in the northern and western parts of the TP. Highest mean wind speeds occur in spring and lowest in autumn. During 1980–2005, annual and seasonal mean wind speeds show statistically decreasing trends at most stations. The mean trend magnitude for annual mean wind speed is −0.24 m s−1 decade−1, with the maximum decline in spring (−0.29 m s−1 decade−1) and minimum in autumn (−0.19 m s−1 decade−1). Both annually and in different seasons, wind speed is significantly negatively correlated with mean temperature, minimum temperature, maximum temperature, and the TP index, but significantly positively correlated with sunshine duration. Wind speed trends fail to show a simple elevation dependency but speeds are positively correlated with meridional surface temperature/pressure gradients. Warming in the TP may weaken the latitudinal gradients of both regional temperature and surface pressure, thus altering the regional atmospheric circulation and accounting in part for the observed decline of wind speed.
A stable‐isotope methodology for measurement of soil‐applied zinc‐fertilizer recovery in durum wheat (Triticum durum)
Authors: McBeath Therese M. , McLaughlin Michael J. , Kirby Jason K. , Degryse Fien
Published: August 2013

A growth‐chamber study was used to develop a zinc stable‐isotope (67Zn) tracing technique to directly measure the amount of soil‐applied zinc (Zn) granular fertilizer taken up by durum wheat (Triticum durum L.) in four different soil types. The 67Zn‐tracer technique was then applied under field conditions at one site to test the ability of the method to measure the crop recovery of soil‐applied Zn granular fertilizer (67Zn). The technique was developed by comparing plants treated with nil Zn fertilizer to natural‐abundance‐Zn‐coated fertilizer and 67Zn‐coated fertilizer with plant parts analyzed for Zn isotopic composition using inductively coupled plasma–mass spectrometry. Zinc‐fertilizer recovery under growth‐chamber conditions was inversely related to the concentration of labile Zn in soils, with the plants on the most Zn‐deficient soils having the greatest amount of Zn derived from the added fertilizer. Zinc derived from fertilizer ranged from 0.3% (Luvisol) to 0.6% (Solonetz) to 13% (Calcisol) and 18% (Lixisol) for soils with DTPA‐extractable Zn of 3.5–0.21 mg kg–1. Across the experiments, fertilizer recovery was measurable but very low (< 1% of added fertilizer being recovered by durum wheat). The recovery of Zn added to the Luvisol was slightly higher in the field than in the glasshouse (but all < 0.1%). Using this stable‐isotope technique, it was possible to directly assess the supply of soil‐applied Zn fertilizers to crop plants.
Nutrient leaching from clay soil monoliths with variable past manure inputs
Authors: Ulén Barbro , Eriksson Ann Kristin , Etana Ararso
Published: August 2013

Overall, arable soils in Sweden are currently generally close to phosphorus (P) balance, but excessive P accumulation has occurred on animal fur farms, i.e., those rearing mink (Mustela vison) and foxes (Alopex lagopus and Vulpes vulpes). Manure P from these farms has sometimes regarded as sparingly soluble. Laboratory lysimeter topsoil trials with simulated rain demonstrated that potential leaching of P in dissolved reactive form (DRP) can be very high, even for heavy clay (50%–65%) soils. The Swedish/Norwegian soil test P‐AL (soil P extracted with acid NH4 lactate, AL) proved useful as a potential indicator of DRP leaching risk (regression coefficient [R2] = 0.89) from fur farms. The upper 5‐cm soil layer, with 190% higher (median) soil P status than the 5–20 cm layer, was the major source of potential DRP leaching through soil columns at the site, despite having been under grass or green fallow for the past 8 y. In percolate from topsoil lysimeters, DRP concentration increased by 0.29 mg L–1 after the long‐term manure application but only by 0.14 mg L–1 after the single slurry application when compared to no addition of slurry. Therefore, the build‐up to a high soil P status due to the long‐term application of mink manure was more important than a single application of pig slurry at a rate corresponding to 22 kg P ha–1 with respect to soil leachate DRP losses in this lysimeter study. The study stresses the importance of precision farming, in which the amount of slurry‐P applied is based on testing the already existing soil P content.
Effects of tail‐clipping on survivorship and growth of larval salamanders
Authors: Polich Rebecca L. , Searcy Christopher A. , Shaffer H. Bradley
Published: August 2013

Tissue samples used for genetic analyses are increasingly necessary for proper management of rare or endangered species, yet growing evidence suggests that traditional methods used to sample or mark amphibians have detrimental fitness effects. We used a semi‐natural mesocosm experiment to determine the effect of larval tail‐clipping on growth and survival of the endangered California tiger salamander. Even with relatively extreme levels of tail loss, we found no effect on survival, mass, or snout‐vent length. We recommend larval tail‐clipping as a low‐impact method for collecting tissue samples from pond‐breeding amphibians. © 2013 The Wildlife Society.
EFFECT OF RAINFALL INTENSITY, SLOPE, LAND USE AND ANTECEDENT SOIL MOISTURE ON SOIL EROSION IN AN ARID ENVIRONMENT
Authors: Ziadat F. M. , Taimeh A. Y.
Published: August 2013

Most climate change scenarios predict a significant increase in the frequency of high intensity rainfall events especially in the dry areas, which will increase runoff and soil erosion. Understanding the factors that control soil erosion is crucial to recommending appropriate measures to protect soils and reduce their vulnerability. The objective of this research was to investigate the effect of rainfall intensity, slope, land use and antecedent soil moisture on soil erosion and runoff. Twelve sites from Al‐Muwaqqar watershed, Jordan, were selected to represent six slope angles: 1, 2, 3, 5, 7 and 9%. Two sites, one cultivated with barley and one as rangeland, were selected within each slope. Erosion was measured under three rainfall intensities: 3, 5 and 10 mm h−1; and three different antecedent soil moisture contents: dry, wet and very wet; using a rotating disk rainfall simulator. Regression equations indicated that rainfall intensity was the most important factor affecting soil erosion and that erosion could occur at a relatively small intensity on wet soils as a result of subsequent rainfall events. Soil erosion on cultivated land was primarily affected by moisture content, while on uncultivated land, it was mostly affected by slope steepness. Rainfall intensity, slope and antecedent moisture explained 84–89 and 59–66% of the variation in runoff and soil loss, respectively. The results indicated the significant influence of cultivating the land on soil erosion. Copyright © 2013 John Wiley & Sons, Ltd.
LAND SENSITIVITY TO DESERTIFICATION IN THE DOMINICAN REPUBLIC: AN ADAPTATION OF THE ESA METHODOLOGY
Authors: Izzo M. , Araujo N. , Aucelli P. P. C. , Maratea A. , Sánchez A.
Published: August 2013

Many elements determine land sensitivity to desertification, whose analysis requires multifactorial approaches to be used. The environmental sensitive areas methodology is a well‐known approach to estimate sensitivity to desertification that accounts for multiple interacting driving forces, conceived and validated in a Mediterranean environment. We show that the environmental sensitive areas methodology can be used, with minor modifications, in a tropical context, where it allows the discrimination among environments with different degree of susceptibility to degradation and resilience. The results obtained for the Dominican Republic show that 48·4% of its territory is critically sensitive to desertification, and 16·4% of it is highly critically sensitive to desertification, mostly because of intense and inadequate land use practices. Copyright © 2013 John Wiley & Sons, Ltd.
LONG‐TERM LAND USE INFLUENCES SOIL MICROBIAL BIOMASS P AND S, PHOSPHATASE AND ARYLSULFATASE ACTIVITIES, AND S MINERALIZATION IN A BRAZILIAN OXISOL
Authors: Balota Elcio L. , Yada Ines F. , Amaral Higo , Nakatani Andre S. , Dick Richard P. , Coyne Mark S.
Published: August 2013

Land use choices differentially affect soil physical and biological properties. Tillage choices in particular affect soil erosion, the retention of soil organic matter, and the biological activity that organic matter supports. The present study evaluated the consequences of different cropping and tillage systems (undisturbed forest, coffee plantation, conventional, and no‐tillage row cropping) for soil microbial indicators and sulfur mineralization after 24 years of cropping on an Oxisol (Typic Haplorthox) in an experimental area at Londrina, Brazil. Soil samples were taken at 0–5, 5–10, and 10–20 cm depths and evaluated for microbial biomass P and S, S mineralization, and phosphatase and arylsulfatase activities. Land use affected microbial biomass P and S, and enzyme activity at all depths studied. The cultivated sites had lower values of microbial activity than the undisturbed forested site. Although the coffee site was not tilled and had high organic carbon content, there was low microbial activity, probably due to higher soil acidity and Al content. The estimates of pool stock for microbial P and annual P flux through the soil microbial biomass suggest that these pools are large enough to significantly affect plant nutrient availability. The greater microbial biomass and activity under forested and no‐tillage sites may be attributed, at least partially, to higher organic matter content. The soil microbial variables examined proved to be strong indicators of soil sustainability. Copyright © 2013 John Wiley & Sons, Ltd.
Effects of ellagitannin‐rich berries on blood lipids, gut microbiota, and urolithin production in human subjects with symptoms of metabolic syndrome
Authors: Puupponen‐Pimiä Riitta , Seppänen‐Laakso Tuulikki , Kankainen Matti , Maukonen Johanna , Törrönen Riitta , Kolehmainen Marjukka , Leppänen Tiina , Moilanen Eeva , Nohynek Liisa , Aura Anna‐Marja , Poutanen Kaisa , Tómas‐Barberán Francisco A. , Espín Juan C. , Oksman‐Caldentey Kirsi‐Marja
Published: August 2013

Ellagitannins are polyphenols abundant in strawberries, raspberries, and cloudberries. The effects of a mixture of these berries were studied in a randomized controlled trial with subjects having symptoms of metabolic syndrome. The study focused on serum lipid profiles, gut microbiota, and ellagitannin metabolites. The results indicate that bioavailability of ellagitannins appears to be dependent on the composition of gut microbiota.
The cyclophosphamide equivalent dose as an approach for quantifying alkylating agent exposure: A report from the childhood cancer survivor study
Authors: Green Daniel M. , Nolan Vikki G. , Goodman Pamela J. , Whitton John A. , Srivastava DeoKumar , Leisenring Wendy M. , Neglia Joseph P. , Sklar Charles A. , Kaste Sue C. , Hudson Melissa M. , Diller Lisa R. , Stovall Marilyn , Donaldson Sarah S. , Robison Leslie L.
Published: August 2013

Background

Estimation of the risk of adverse long‐term outcomes such as second malignant neoplasms and infertility often requires reproducible quantification of exposures. The method for quantification should be easily utilized and valid across different study populations. The widely used Alkylating Agent Dose (AAD) score is derived from the drug dose distribution of the study population and thus cannot be used for comparisons across populations as each will have a unique distribution of drug doses.

Methods

We compared the performance of the Cyclophosphamide Equivalent Dose (CED), a unit for quantifying alkylating agent exposure independent of study population, to the AAD. Comparisons included associations from three Childhood Cancer Survivor Study (CCSS) outcome analyses, receiver operator characteristic (ROC) curves and goodness of fit based on the Akaike's Information Criterion (AIC).

Results

The CED and AAD performed essentially identically in analyses of risk for pregnancy among the partners of male CCSS participants, risk for adverse dental outcomes among all CCSS participants and risk for premature menopause among female CCSS participants, based on similar associations, lack of statistically significant differences between the areas under the ROC curves and similar model fit values for the AIC between models including the two measures of exposure.

Conclusion

The CED is easily calculated, facilitating its use for patient counseling. It is independent of the drug dose distribution of a particular patient population, a characteristic that will allow direct comparisons of outcomes among epidemiological cohorts. We recommend the use of the CED in future research assessing cumulative alkylating agent exposure. Pediatr Blood Cancer 2014;61:53–67. © 2013 Wiley Periodicals, Inc.
Detection of genetic abnormalities by using CVS and FISH prior to fetal reduction in sonographically normal appearing fetuses
Authors: Rosner Mara , Pergament Eugene , Andriole Stephanie , Gebb Juliana , Dar Pe'er , Evans Mark I.
Published: August 2013

Objective

To examine the ability of chorionic villus sampling (CVS) and fluorescence in situ hybridization (FISH) to detect aneuploidy before first trimester fetal reduction (FR) in sonographically normal‐appearing fetuses.

Methods

A retrospective review of 470 patients referred to our unit for FR from January 2007–March 2011. Prenatal diagnosis was offered to all. FR was performed after next‐day FISH results. Abnormalities were categorized by ultrasound, FISH, and/or karyotype. Sensitivity, specificity, positive predictive value, and negative predictive value of pre‐FR FISH were calculated.

Results

Four hundred thirty‐two of 470 patients seen were first trimester. 24/432 (5.2%) were excluded for abnormal ultrasound findings, including nuchal translucency (NT) > 3.0 mm, and 360 (88.2%) underwent CVS before FR. Ten fetuses were then excluded for euploid sex mosaicism. 10/350 (2.9%) patients with normal ultrasounds had abnormal FISH confirmed by karyotype. 9/350 (2.6%) patients with normal FISH had an abnormal karyotype necessitating follow up amniocentesis in which the clinically relevant discordancy was confirmed in one case (1/350, 0.3%). Pre‐FR FISH had a 90% sensitivity, 99.4% specificity, 83.3% positive predictive value, and 99.7% negative predictive value.

Conclusions

3.1% of patients with normal‐appearing fetuses prior to first trimester FR had a fetus with an abnormal karyotype of which FISH detected 90%. CVS with FISH prior to FR adds significant information that can guide reduction decisions. © 2013 John Wiley & Sons, Ltd.
Investigation of luminescent properties of ZnO nanoparticles for their use as a down‐shifting layer on solar cells
Authors: Apostoluk Aleksandra , Zhu Yao , Canut Bruno , Masenelli Bruno , Delaunay Jean‐Jacques , Znajdek Katarzyna , Sibiński Maciej
Published: August 2013

Commercially available solar cells (e.g. CdS/CdTe, CIGS, c‐Si) have a spectrally narrow absorption band when compared to the solar emission spectrum. The UV‐wavelength response of a solar cell (SC) can be improved by the application of a luminescent down‐shifting layer (LDSL) on the SC front side, permitting the conversion of short‐wavelength photons to the longer wavelength photons better matching the SC’s absorption spectrum. The ideal down‐shifting material must possess a large Stokes shift and have a high luminescence quantum yield. We propose the use of the LDSL containing ZnO nanoparticles of less than 5 nm in diameter able to absorb UV light (λ < 400 nm), where the solar cell spectral response (SR) is low, and re‐emitting at longer wavelengths (λ > 425 nm), where the typical SC’s SR increases. ZnO nanoparticles were synthesized by a low energy cluster beam deposition (LECBD) technique and their luminescent properties were studied as a function of the oxygen partial pressure (OPP) applied during the deposition process. The stoichiometry and crystallinity of ZnO nanoparticles can be controlled via the adjustment of the OPP. It was also observed that there exists an optimal value of the oxygen pressure introduced during the LECBD process, which permits to obtain the highest visible photoluminescence emission, necessary for an efficient down‐shifting. The yield of the down‐shifting in ZnO nanoparticle layer was determined varying the excitation wavelength using the photoluminescence excitation technique.
Atmosphere–sea ice interaction in early summer in the Antarctic: evaluation and challenges of a regional atmospheric model
Authors: Valkonen T. , Vihma T. , Johansson M. M. , Launiainen J.
Published: August 2013

Antarctic sea ice areas have only been the main focus for a few studies combining observations and three‐dimensional atmospheric model experiments. This study presents simulations over the Weddell Sea in early summer, applying the polar‐optimized version of the Weather Research and Forecasting model (Polar WRF). The results are compared against observations from the drifting experiment Ice Station Polarstern, which took place on 28 November 2004–2 January 2005. The Polar WRF model showed good skill in simulating synoptic‐scale variations. The diurnal cycles of surface variables were reproduced, but the amplitude was overestimated for most of the variables and the simulations were characterized by a cold temperature bias at night. The major challenges related to the modelling of the atmosphere over Antarctic sea ice were found to be associated with clouds, atmospheric boundary‐layer processes and processes in the sea ice and snow layer. Temporal variations in the errors in cloud cover generated large errors in long‐wave radiation fluxes. In the boundary layer, the overestimated downward sensible heat flux was partly compensated for by the underestimated downward long‐wave radiation at the surface. The underestimated downward long‐wave flux started to dominate as the stability increased and generated the cold temperature bias at the surface. Problems with the surface energy balance, as found in this study, could be reduced by applying more advanced schemes for snow and ice thermodynamics.
Accuracy of a freehand sculpting tool for unicondylar knee replacement
Authors: Smith Julie R. , Riches Philip E. , Rowe Philip J.
Published: August 2013

Background

Unicondylar knee replacement is technically challenging and malalignment of the implant components is one of the factors that results in high failure rates. Surgical robotics with navigation is emerging as a potential solution to improve the accuracy of implant placement.

Methods

The accuracy of performing unicondylar knee replacement using a freehand sculpting, semi‐active robotic tool was investigated using 20 synthetic femurs and tibia. Resultant femoral and tibial implant placement was compared to the planned implant position.

Results

The maximum rotational error was 3.2o and RMS angular error was 1.46o across all orientations, for both the tibia and femoral implants. The maximum translational error was 1.18 mm and the RMS translational error across all directions was 0.61 mm.

Conclusions

The freehand sculpting tool produced accurate implant placement with small errors comparable to those reported by other robotic‐assistive devices on the market for unicondylar knee replacement. Copyright © 2013 John Wiley & Sons, Ltd.
A Study of Nitrogen Pickup from the Slag during Waiting Time of Ladle Treatment
Authors: Allertz Carl , Kojola Niklas , Hui Wang , Sichen Du
Published: August 2013

An investigation of the nitrogen pickup of liquid steel from ladle slag after vacuum degassing was made. Nitride capacities, CN, of a number of ladle slags were determined at controlled nitrogen and oxygen potentials at 1873 K. The nitride capacities in the composition range studied were found to be very low. In accordance with the literature, the nitride capacity was found to increase with increasing SiO2 content. Industrial trials were performed. The nitrogen content of the steel was determined before and after vacuum degassing as well as after the waiting period. Three different trends of the variation of nitrogen content in the steel were observed. Both the laboratory study and the industrial trials revealed that the transfer of nitrogen from slag to steel was not the reason for nitrogen pickup in the steel subsequent to vacuum degassing.
Research skills and STEM undergraduate research students' aspirations for research careers: Mediating effects of research self‐efficacy
Authors: Adedokun Omolola A. , Bessenbacher Ann B. , Parker Loran C. , Kirkham Lisa L. , Burgess Wilella D.
Published: August 2013

Positive student outcomes of undergraduate research experiences (UREs) have been well documented, however, many studies have neglected the logical relationship among outcomes, the processes through which they are achieved, and the contextual and participant factors at play in UREs. This study uses structural equation modeling to explore these issues in a URE program. The study tested a hypothesized model of the mediating effect of participant research self‐efficacy on the relationship between their research skills and desire to persist in science. Results indicate that research skills and research self‐efficacy predict student aspirations for research careers, and that the effects of research skills are partially mediated through self‐efficacy beliefs. © 2013 Wiley Periodicals, Inc. J Res Sci Teach 50: 940–951, 2013
The Ainsa Fold and thrust oblique zone of the central Pyrenees: Kinematics of a curved contractional system from paleomagnetic and structural data
Authors: Muñoz Josep‐Anton , Beamud Elisabet , Fernández Oscar , Arbués Pau , Dinarès‐Turell Jaume , Poblet Josep
Published: August 2013

Integration of structural, stratigraphic, and paleomagnetic data from the N–S trending structures of the Ainsa Oblique Zone reveals the kinematics of the major thrust salient in the central Pyrenees. These structures experienced clockwise vertical axis rotations that vary from 70° in the east (Mediano anticline) to 55° in the west (Boltaña anticline). Clockwise vertical axis rotations of 60° to 45° occurred from early Lutetian to late Bartonian when the folds and thrusts of the Ainsa Oblique Zone developed. This vertical axis rotation stage resulted from a difference of about 50 km in the amount of displacement on the Gavarnie thrust and an accompanying change in structural style at crustal scale from the central to the western Pyrenees, related to the NE–SW trending pinch out of Triassic evaporites at its basal detachment. A second rotation event of at least 10° took place since Priabonian, as a result of a greater displacement of the Serres Marginals thrust sheet with respect to the Gavarnie thrust sheet above the Upper Eocene‐Oligocene salts. The deduced kinematics demonstrates that the orogenic curvature of the central Pyrenees is a progressive curvature resulting from divergent thrust transport direction. Layer parallel shortening mesostructures and kilometer‐scale folds also developed by a progressive curvature related to divergent shortening directions during vertical axis rotation. Rotation space problems were solved by along‐strike extension which triggered the formation of transverse extensional faults and diapirs at the outer arcs of structural bends.
Dating brittle tectonic movements with cleft monazite: Fluid‐rock interaction and formation of REE minerals
Authors: Berger A. , Gnos E. , Janots E. , Whitehouse M. , Soom M. , Frei R. , Waight T. E.
Published: August 2013

Two millimeter‐sized hydrothermal monazites from an open fissure (cleft) that developed late during a dextral transpressional deformation event in the Aar Massif, Switzerland, have been investigated using electron microprobe and ion probe. The monazites are characterized by high Th/U ratios typical of other hydrothermal monazites. Deformation events in the area have been subdivided into three phases: (D1) main thrusting including formation of a new schistosity, (D2) dextral transpression, and (D3) local crenulation including development of a new schistosity. The two younger deformational structures are related to a subvertically oriented intermediate stress axis, which is characteristic for strike slip deformation. The inferred stress environment is consistent with observed kinematics and the opening of such clefts. Therefore, the investigated monazite‐bearing cleft formed at the end of D2 and/or D3, and during dextral movements along NNW dipping planes. Interaction of cleft‐filling hydrothermal fluid with wall rock results in rare earth element (REE) mineral formation and alteration of the wall rock. The main newly formed REE minerals are Y‐Si, Y‐Nb‐Ti minerals, and monazite. Despite these mineralogical changes, the bulk chemistry of the system remains constant and thus these mineralogical changes require redistribution of elements via a fluid over short distances (centimeter). Low‐grade alteration enables local redistribution of REE, related to the stability of the accessory phases. This allows high precision isotope dating of cleft monazite. 232Th/208Pb ages are not affected by excess Pb and yield growth domain ages between 8.03 ± 0.22 and 6.25 ± 0.60 Ma. Monazite crystallization in brittle structures is coeval or younger than 8 Ma zircon fission track data and hence occurred below 280°C.
Yarning Circles In The Literacy Classroom
Authors: Mills Kathy A. , Sunderland Naomi , Davis‐Warra John
Published: August 2013

This article explains how the speaking and listening practice of yarning circles can be used in the literacy classroom. The article opens with an account of a live enactment of yarning circles with elementary students in a mainstream classroom in Australia. It explains the purpose and origin of yarning circles in Indigenous communities, and provides steps for establishing and implementing the practice in classrooms.
Fetal right ventricular contraction and relaxation times at 11–13 weeks' gestation on speckle tracking imaging
Authors: Persico N. , Fabietti I. , Baffero G. M. , Fedele L. , Nicolaides K. H.
Published: August 2013

Objective

To examine the contraction time and relaxation time of the right ventricle at 11–13 weeks' gestation in trisomy 21 and euploid fetuses by speckle tracking ultrasound imaging.

Methods

Measurement of fetal nuchal translucency (NT) thickness, Doppler assessment for tricuspid regurgitation and reversed A‐wave in the ductus venosus (DV) and fetal echocardiography were performed immediately before chorionic villus sampling for fetal karyotyping at 11–13 weeks' gestation. Digital videoclips of the four‐chamber view of the fetal heart were recorded and analyzed offline using speckle tracking imaging software. The contraction time, which is the time between the highest and lowest peaks in the right ventricular area, and relaxation time, which is the time between the lowest and the subsequent highest area peak, were measured and expressed as a percentage of the duration of the cardiac cycle. Values in trisomy 21 and euploid fetuses were compared.

Results

Mean contraction time and relaxation time in 119 euploid fetuses were 52.1% (95% CI, 51.6–52.8%) and 47.8% (95% CI, 47.2–48.4%), respectively. In 21 trisomy 21 fetuses, mean contraction time was significantly higher (57.0% (95% CI, 55.2–58.9%); P < 0.01) and relaxation time lower (42.9% (95% CI, 41.1–44.8%); P < 0.01) than in euploid fetuses. Multiple regression analysis showed that significant contributions to contraction time and relaxation time were provided by fetal karyotype, NT and tricuspid regurgitation, but not by reversed A‐wave in the DV or the presence of a cardiac defect.

Conclusion

In first‐trimester fetuses with trisomy 21 and in euploid fetuses with increased NT and tricuspid regurgitation there is evidence of increased right ventricular contraction time and shortening of the relaxation time. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd
Ultrasmall metal nanoclusters for bio‐related applications
Authors: Tan Xiaohong , Jin Rongchao
Published: August 2013

The study of ultrasmall metal nanoclusters (NCs, ranging from subnanometer to ca 2 nm) is evidently a quickly evolving field in current nanoscience and nanotechnology research. Metal NCs, typically composed of several to hundreds of metal atoms, have attracted great interest in recent years owing to their unique properties including ultrasmall size and enhanced photoluminescence, together with other properties such as excellent photostability, low toxicity, and good biocompatibility desired for biological applications. This review summarizes recent advances in the field of bio‐related applications of metal NCs materials. We highlight the applications of metal NCs for biosensor development, fluorescent biological imaging, and biomedical research, and finally discuss briefly some current challenges and future work. WIREs Nanomed Nanobiotechnol 2013, 5:569–581. doi: 10.1002/wnan.1227

This article is categorized under:

Diagnostic Tools > Biosensing

Diagnostic Tools > In Vitro Nanoparticle-Based Sensing

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging
Historical perspectives on invasive grasses and their impact on wildlife in Australia
Authors: Cook Garry D. , Grice A. C.
Published: August 2013

In recent years, there have been declines of varying severity in many vertebrate species across much of the sparsely populated savannas of northern Australia, and adding to the dismal record of extinctions from arid and semi‐arid central Australia since European colonization. It is likely that multiple factors are responsible for the current wave of extinctions, but they are occurring in areas of sparse human population in extensive, seemingly unmodified landscapes. Habitat change is one likely contributing factor, with invasive exotic grasses an important component in some regions. Historically, conservation of native vertebrates has been poor in Australia, with many species being considered vermin under legislation. As late as the 1960s much scientific research was aimed at controlling species that are now considered threatened under legislation. Through the 20th century substantial efforts to introduce exotic pasture species saw the introduction for trial of twice as many species of grasses and legumes as occur naturally on the whole Australian continent. The legacy of these programs is the spread of grasses that, through a range of processes, lead to simplification of floristic structure and reduction in plant species diversity and habitat suitability for many native mammals. Management of these invasive species should focus on preventing their spread into and establishment in new regions, and controlling them where they are established. State and transition models may provide a framework for considering the management and environmental triggers that could lead to re‐establishment of native grasses. © 2013 The Wildlife Society.
Umgang mit Patientenverfügungen in der Praxis
Authors: Neitzke Gerald
Published: August 2013

Einleitung

Patientenverfügungen (PV) sind seit 2009 gesetzlich geregelt. Bei entscheidungsunfähigen Patienten muss der Wille individuell ermittelt werden: Außer der PV können dazu auch Behandlungswünsche und der mutmaßliche Wille herangezogen werden. Vor Anwendung einer PV sollten deren Gültigkeit, die Situationsadäquatheit und der Bezug zu geplanten Therapiemaßnahmen geprüft werden. Advance Care Planning (ACP) setzt sich für eine umfassende Patientenvorsorge und deren praktische Umsetzung ein.
Assessing Randomised Clinical Trials of Cognitive and Exposure Therapies for Gambling Disorders: A Systematic Review
Authors: Smith David P. , Dunn Kirsten I. , Harvey Peter W. , Battersby Malcolm W. , Pols Rene G.
Published: August 2013

Aims:Problem or pathological gambling is associated with significant disruption to the individual, family and community with a range of adverse outcomes, including legal, financial and mental health impairment. It occurs more frequently in younger populations, and comorbid conditions are common. Cognitive–behaviour therapy (CBT) is the most empirically established class of treatments for problematic gambling. This article reports on a systematic review and evaluation of randomised clinical trials (RCTs) concerning two core techniques of CBT: cognitive and behavioural (exposure-based) therapies.Methods:PsycINFO, MEDLINE and the Cochrane library were searched from database inception to December 2012. The CONsolidated Standards Of Reporting Trials (CONSORT) for non-pharmacological treatments was used to evaluate each study.Results:The initial search identified 104 references. After two screening phases, seven RCTs evaluating either cognitive (n= 3), exposure (n= 3) or both (n= 1) interventions remained. The studies were published between 1983 and 2003 and conducted across Australia, Canada, and Spain. On average, approximately 31% of CONSORT items were rated as ‘absent’ for each study and more than 52% rated as ‘present with some limitations’. For all studies, 70.83% of items rated as ‘absent’ were in the methods section.Conclusions:The findings from this review of randomised clinical trials involving cognitive and exposure-based treatments for gambling disorders show that the current evidence base is limited. Trials with low risk of bias are needed to be reported before recommendations are given on their effectiveness and clinicians can appraise their potential utility with confidence.
Methylphenidate treatment causes oxidative stress and alters energetic metabolism in an animal model of attention-deficit hyperactivity disorder
Authors: Comim Clarissa M. , Gomes Karin M. , Réus Gislaine Z. , Petronilho Fabrícia , Ferreira Gabriela K. , Streck Emílio L. , Dal-Pizzol Felipe , Quevedo João
Published: August 2013

Objectives

To evaluate oxidative damage through the thiobarbituric acid-reactive species (TBARS) and protein carbonyl groups; antioxidant enzymatic system – superoxide dismutase (SOD) and catalase (CAT); and energetic metabolism in the brain of spontaneously hypertensive adult rats (SHR) after both acute and chronic treatment with methylphenidate hydrochloride (MPH).

Methods

Adult (60 days old) SHRs were treated during 28 days (chronic treatment), or 1 day (acute treatment). The rats received one i.p. injection per day of either saline or MPH (2 mg/kg). Two hours after the last injection, oxidative damage parameters and energetic metabolism in the cerebellum, prefrontal cortex, hippocampus, striatum and cortex were evaluated.

Results

We observed that both acute and/or chronic treatment increased TBARS and carbonyl groups, and decreased SOD and CAT activities in many of the brain structures evaluated. Regarding the energetic metabolism evaluation, the acute and chronic treatment altered the energetic metabolism in many of the brain structures evaluated.

Conclusion

We observed that both acute and chronic use of methylphenidate hydrochloride (MPH) in adult spontaneously hypertensive rats (SHRs) was associated with increased oxidative stress and energetic metabolism alterations. These data also reinforce the importance of the SHR animal model in further studies regarding MPH.
Fruit juice drinks prevent endogenous antioxidant response to high-fat meal ingestion
Authors: Miglio Cristiana , Peluso Ilaria , Raguzzini Anna , Villaño Deborah V. , Cesqui Eleonora , Catasta Giovina , Toti Elisabetta , Serafini Mauro
Published: August 2013

High-fat meals (HFM) induce metabolic stress, leading to the activation of protective mechanisms, including inflammation and endogenous antioxidant defences. In the present study, we investigated the effects of antioxidant-rich fruit juice drinks on the endogenous antioxidant response induced by HFM. In a double-blind, cross-over design (10 d washout), fourteen overweight volunteers were randomly assigned to one of the following interventions: HFM+500 ml placebo beverage (HFM-PB, free from fruit); HFM+500 ml antioxidant beverage 1 (HFM-AB1; apple, grape, blueberry and pomegranate juices and grape skin, grape seed and green tea extracts); HFM+500 ml antioxidant beverage 2 (HFM-AB2; pineapple, black currant and plum juices). HFM-PB consumption increased the plasma levels of thiols (SH) (4 h,P< 0·001) and uric acid (UA) (2 h,P< 0·01) and total radical-trapping antioxidant parameter (TRAP) (4 h,P< 0·01). Following the consumption of drinks, UA production was significantly reduced with respect to placebo beverage consumption 8 h after HFM-AB2 consumption (P< 0·05). SH levels were reduced 0·5 (P< 0·05), 1 (P< 0·05) and 2 h (P< 0·01) after HFM-AB1 consumption and 2, 4 and 8 h (P< 0·05) after HFM-AB2 consumption. Plasma TRAP (2 h,P< 0·001) and urinary ferric reducing antioxidant power (0–8 h,P< 0·01) were increased by HFM-AB1 consumption, the drink with the highestin vitroantioxidant capacity, but not by HFM-AB2 consumption. In urine, UA levels were significantly increased from basal levels after the consumption of HFM-PB and HFM-AB2. However, neither of the beverages increased the urinary excretion of UA with respect to the placebo beverage. In conclusion, the increase in UA and SH levels induced by HFM as part of an endogenous antioxidant response to postprandial stress can be prevented by the concomitant ingestion of antioxidant-rich fruit juice drinks.