bluuebunny/crossref_metadata_2025 huggingface dataset:
Hard Red Spring Wheat Response to Row Spacing, Seeding Rate, and Nitrogen
Authors: Chen Chengci , Neill Karnes , Wichman Dave , Westcott Malvern
Published: August 2008

Row spacing, plant density, and N application timing can be manipulated to optimize plant growth and spatial distribution, therefore maximizing sunlight, nutrients, soil water use efficiency and grain yield. A 2‐yr field study to evaluate the effects of four seeding rates (108, 215, 323, and 430 seeds m−2), two row spacings (15 and 30 cm), and three N treatments (FA1, 100% at seeding; FA2, 50% at seeding and 50% at tiller formation; and FA3, 50% at seeding and 50% at shoot elongation) on grain yield of McNeal hard red spring wheat (Triticum aestivum L.) was conducted in central Montana. Spring wheat accumulated greater biomass at a faster rate under the 15‐cm row spacing than the 30‐cm row spacing. Grain yield was 410 and 412 kg ha−1 greater at 15‐cm than at 30‐cm row spacings in 2004 and 2005, and the yield increase was primarily attributed to 44 and 40 more spikes m−2 at 15‐cm than at 30‐cm row spacing in 2004 and 2005, respectively. Grain yield was not significantly affected by the N treatments, thus all N should be applied at seeding. The optimum seeding rate was 215 seeds m−2. Tillers at higher seeding rates had larger phyllochrons and greater mortalities. Low protein content was found in FA3 and high seeding rate treatments in 2005. Narrow row spacing is recommended for high spring wheat yield in the northern Great Plains. This yield increase cannot be achieved by increasing seeding rate at wide row spacing.
Adoption and Spatial Diversity of Later Generation Modern Rice Varieties in the Philippines
Authors: Launio C. C. , Redondo G. O. , Beltran J. C. , Morooka Y.
Published: August 2008

Not much information has been publicly available on the diffusion of modern varieties (MVs) from the 1990s and on current diversity of rice (Oryza sativa L.) varieties in farmer fields. Using national household surveys of Philippine growers conducted in 1993, 1997, and 2002, this study describes the adoption of specific MVs and variety groups in farmer fields; measures the adoption rates of newly released varieties; and analyzes the spatial diversity of varieties planted in farmer fields. Data showed that IR64, IR74, IR42, and Burdagol are enduring varieties from 1970s and 1980s, and PSB Rc18, PSB Rc10, PSB Rc28, Masipag, PSB Rc14, and PSB Rc82 are the most commonly planted new varieties. The MV3 varieties (released mid‐1980s to mid‐1990s) were popularly planted with an observed decrease in the use of MV2s (released mid‐1970s to mid‐1980s) and increase in the use of MV4s (released after 1995). Around 30 to 40% of the total rice area is planted to new rice varieties and the aggregate replacement period of rice varieties is around 8 to 11 yr, with faster adoption rates during dry season (DS) in irrigated areas. On average, only 10 varieties occupy around 70% of the rice area in major rice‐producing provinces in one season. Indices of spatial diversity show wide variability across provinces in terms of the richness of diversity, dominance of specific varieties, and the equality of abundance, but no clear trend across periods. Policymakers are thus encouraged to continually support and strengthen the current efforts of public rice breeding research and extension, even as research beyond analysis of on‐farm morphological diversity is recommended.
Differential Response of Cultivated and Weedy (Red) Rice to Recent and Projected Increases in Atmospheric Carbon Dioxide
Authors: Ziska Lewis H. , McClung Anna
Published: August 2008

To determine whether recent or projected increases in atmospheric [CO2] favor cultivated rice or its weedy relative, red rice, we examined the initial growth and vegetative characteristics of these two groups using six weedy red rice (RR) biotypes and six cultivated rice (CR) varieties at CO2 concentrations that corresponded to the 1940s, current levels, and that projected for the middle of this century (300, 400, and 500 μmol mol−1, respectively). Increasing [CO2] resulted in significant increases in initial leaf area and root weight for the RR, as early as 27 d after sowing (DAS) at 500 μmol mol−1. By 55 DAS, significant CO2 by type (RR vs. CR) interactions were observed with RR demonstrating a 55 and 62% increase in plant biomass and leaf area, respectively, relative to the CR at 500 μmol mol−1 [CO2]. Overall, these results indicate a greater physiological plasticity and genetic diversity among RR relative to CR that may impact weed/crop competition as atmospheric CO2 increases. However, this greater variation may also provide a unique genetic resource that could be incorporated into CR varieties to increase their adaptability to rising atmospheric CO2.
Yield Gap Analysis between Dry and Wet Season Rice Crop Grown under High‐Yielding Management Conditions
Authors: Yang Woonho , Peng Shaobing , Laza Rebecca C. , Visperas Romeo M. , Dionisio‐Sese Maribel L.
Published: August 2008

Rice (Oryza sativaL.) grain yield highly varies depending on cropping seasons under the tropical irrigated conditions. This study aimed to (i) compare the grain yield of rice in dry season (DS) and wet season (WS) and (ii) determine climatic and physiological factors critical to the yield gap between DS and WS. Six genotypes, two each for indica inbred, indica/indica F1hybrid, and the second‐generation new plant type, were grown in DS and WS of 2003 and 2004. Significantly higher grain yields were achieved in DS than in WS by 94% for 2003 and 35% for 2004. Mean daily radiation was higher in DS than WS, particularly during grain filling stage than before flowering. The greater radiation during ripening in DS contributed to the higher grain yield. Major difference in biomass production between DS and WS occurred after flowering. Greater biomass accumulation from flowering to physiological maturity was associated with higher grain yield in DS than in WS, but not translocation of biomass accumulated before flowering to grains. Higher grain yield in DS was partly the result of greater spikelets due to higher spikelet production efficiency per unit biomass at flowering. Aboveground total biomass at physiological maturity was a crucial physiological factor to the yield gap between DS and WS. Daily mean radiation and biomass accumulation during ripening, and sink production efficiency per unit biomass were critical factors to the yield gap of rice between DS and WS under the high‐yielding tropical irrigated conditions.
Separation of Cotton Cultivar Testing Sites based on Representativeness and Discriminating Ability Using GGE Biplots
Authors: Baxevanos Dimitrios , Goulas Christos , Rossi Jesus , Braojos Eva
Published: August 2008

An important task of multienvironment trials (MET) analysis is evaluation of testing sites for megaenvironment differentiation and selection of “ideal” candidate location to improve the efficiency of cultivar selection and recommendation. The objectives of this research work were (i) to divide the Spanish cotton (Gossypium hirsutum L.) testing locations into megaenvironments and (ii) to separate the testing locations based on their distance to the “ideal” location, discriminating ability, representativeness, and uniqueness. GGE biplot was employed to analyze eight 1‐yr and two multiyear (3‐yr, 4‐yr) balanced datasets from 1999 to 2006 cotton trials of Delta & Pine Land Co. in Spain for yield, fiber quality traits, a selection index (SI) based on yield and quality, and Verticillium wilt (Verticillium dahliae Kleb.) disease infestation level. Yearly GGE biplots revealed crossover genotype × location interactions, but not large enough to divide the area into different megaenvironments. Therefore, the Spanish cotton region may be considered as a complex megaenvironment and cultivar recommendation may be based on both mean performance and stability. Las Cabezas location was the closest to an ideal based on both yield and the SI regardless of the change from plastic to nonplastic mulching cultural practice. Aznalcazar did not provide unique information and could be dropped as a test site. The separation of test locations for their discriminating ability and representativeness provided useful information on the effectiveness of each testing location for developing and/or recommending cultivars with specific or broad adaptation. In this sense, Lebrija could be considered as trait‐specific selection environment for early screening of verticillium tolerant genotypes.
A Wheat Grazing Model for Simulating Grain and Beef Production: Part II—Model Validation
Authors: Zhang X.‐C. , Hunt L. A. , Phillips W. A. , Horn G. , Edward J. , Zhang H.
Published: August 2008

Computer models must be thoroughly evaluated before being used for decision‐making. The objective of this paper is to evaluate the ability of a newly developed wheat grazing model to predict fall–winter forage and winter wheat (Triticum aestivum L.) grain yield as well as daily weight gains of steer (Bos taurus) grazing on wheat pasture in Oklahoma. Experimental data of three independent field studies were used. The first was a variety trial in which fall–winter forage and grain yields were harvested. The second was a planting date experiment in which forage in the fall–winter period and grain yields were harvested. The third was a steer grazing experiment in which standing wheat biomass and steer weight gain were monitored. For the variety trials, the model efficiency (ME), which reflects how well model predictions match measured data (1 means a perfect match), was 0.102 for fall–winter forage prediction and 0.367 for grain yield. For the planting date experiment, the ME was 0.615 for predicting fall–winter forage yields and 0.409 for grain yields when a root downward extension rate of 20 mm d−1 was used. In the steer grazing experiment, the relationship between average daily weight gain and forage allowance was adequately represented by the model. For the total steer weight gains in a wide range of stocking rates and grazing durations, the ME was 0.616. Overall results show that the model, if well calibrated, has the potential to predict fall–winter forage and grain yields as well as mean daily weight gain per steer.
‘Coastal’ and ‘Tifton 44’ Bermudagrass Availability on Animal and Pasture Productivity
Authors: Burns J. C. , Fisher D. S.
Published: August 2008

Hybrid cultivars of bermudagrass [Cynodon dactylon (L.) Pers.] are a major feed source for ruminants across the southeastern United States. This 4‐yr experiment compared animal and pasture performance of ‘Coastal’ and ‘Tifton 44’ bermudagrasses over three canopy heights designated as short (5.6 cm), medium (10.1 cm), and tall (13.1 cm). The relationship of canopy height to ingestive mastication and canopy characteristics was also studied. Soil was a Cecil clay loam (clayey, Kaolinitic thermic Typic Hapludult). Pastures were continuously stocked using variable stocking to maintain the targeted canopy heights. Herbage mass (to soil surface) was similar between Coastal and Tifton 44 (T44) within each canopy height averaging 2.36, 4.08, and 5.25 Mg ha−1. Steer average daily gain (ADG) was greater (P = 0.09) from T44 than Coastal (0.58 vs. 0.51 kg) but no differences were noted in pasture productivity. Increasing herbage mass linearly increased (P < 0.01) ADG (0.40–0.59 kg) but reduced (P < 0.01) stocking rate (16.1–11.2 steers ha−1), which influenced animal days (1810–1079 d ha−1), weight gain (1057–786 kg ha−1), and effective feed units (6392–4452 kg ha−1). Steer ADG increased (P = 0.01) from short to medium canopy height (0.40–0.64 kg) with little change between medium and tall canopy height (0.64–0.59 kg). Tifton 44 pasture is of greater quality than Coastal giving greater ADG but both were productive producing about 1100 kg of gain ha−1 when effectively managed and utilized.
Chlorophyll Measurements and Nitrogen Nutrition Index for the Evaluation of Corn Nitrogen Status
Authors: Ziadi Noura , Brassard Marianne , Bélanger Gilles , Claessens Annie , Tremblay Nicolas , Cambouris Athyna N. , Nolin Michel C. , Parent Léon‐Étienne
Published: August 2008

Plant‐based diagnostic techniques are used to determine the level of crop N nutrition but there is limited comparative research on the different methods. Our objectives were to establish the relationship between chlorophyll meter (CM) readings and N nutrition index (NNI) during the corn (Zea mays L.) growing season, and to compare both methods as diagnostic tools for predicting grain yield response to N fertilization. The study was established at eight site‐years using four to seven N fertilization rates. The CM readings from the youngest collared leaf were taken on five to eight sampling dates in 2004, 2005, and 2006 along with NNI determinations. Generally, CM readings and NNI increased with increasing N rates. Chlorophyll meter readings and relative CM (RCM) readings were related to NNI, but the intercepts and/or slope of the response curves varied with site‐year. Because they are site‐specific, these relationships may not be reliable indicators of corn N status. The relationship between CM readings and relative grain yield (RY) at stage of development ≈V12 was also site‐specific. Relative CM readings (RY = −0.64 + 1.65 RCM if RCM ≤ 0.98 and RY = 0.97 if RCM > 0.98; R2 = 0.60) and NNI (RY = −0.34 + 1.47 NNI if NNI ≤ 0.88 and RY = 0.96 if NNI > 0.88; R2 = 0.79) at stage of development ≈V12 were related to RY. These two relationships were stable across site‐years and could be used to detect and quantify N deficiencies of corn.
Training dairy bull calves to stay within light-built electric fences (Research Note)
Authors: MARTISKAINEN P. , TUOMISTO L. , HUUSKONEN A.
Published: August 2008

Training cattle to avoid electric fences before turnout to grazing reduces the risk of the animals breaking out from their paddock. We investigated the time needed for dairy bull calves to learn to avoid a light-built electric fence. Nineteen dairy bull calves were trained to an electric fence in a training yard during seven days. The number of electric shocks the animals received from the training fence was recorded continuously. After the training period, the calves were turned to pasture. Nine of the animals were also grazed the following summer as yearlings, and observed before turnout in a smaller enclosure. The calves got more shocks from the fence during training hour 1 than during any of the following seven hours. The number of shocks the calves received from the fence also declined from training day 1 to 2 and from training day 3 to 4. The results indicate that the dairy bull calves learned to avoid an electric fence quickly, even within an hour from release into the training yard. A simple training procedure was sufficient to ensure that the animals could be grazed in and would avoid a light-built electric fencing system as calves and, even after a winter-housing period, as bulls.;
Microbial Fouling of a Reverse Osmosis Municipal Water Treatment System
Authors: Wright Steven J. , Semrau Jeremy D. , Keeney David R.
Published: August 2008

Microbial fouling of a municipal water treatment system using reverse osmosis was investigated. From a combination of growth and molecular assays, it was discovered that the prefilter unit concentrated and facilitated microbial growth, and such growth led to microbial fouling of the reverse osmosis unit. Few cells were observed in the prefilter influent, but substantial microbial contamination was observed in the prefilter effluent, and this correlated with increasing headloss across the prefilter. The effluent caused microbial fouling of the leading elements of the reverse osmosis unit, as determined by reduced permeate flow, analysis of the elements, and assays of the membrane foulant. Both the introduction of microorganisms to the reverse osmosis unit from the prefilter unit and headloss across the prefilter could be effectively controlled through cleansing of the prefilter housing unit with sulfuric acid. Such treatments must be performed at appropriate intervals to prevent subsequent microbial growth in the prefilter unit.
Preparation of Biofilm Electrode with Xanthomonas sp. and Carbon Nanotubes and the Application to Rapid Biochemical Oxygen Demand Analysis in High‐Salt Condition
Authors: Chen Jing , Yu Zhiguo , Sun Jinfeng , Jia Jianbo , Li Genxi
Published: August 2008

A Xanthomonas sp. was isolated from the sludge on the drain outlet of a pharmaceutical factory. Then, the bacterium and carbon nanotubes (CNTs) were co‐attached to an oxygen electrode for rapid analysis of biochemical oxygen demand (BOD). The response current was linear with BOD values in the range 10 to 300 mg/L for standard BOD solution with a response time of 35 seconds (R = 0.9994) and 20 to 580 mg/L for pharmaceutical wastewater with a response time ≤200 seconds (R = 0.9985), which means that this modified electrode might be used for online BOD analysis of pharmaceutical wastewater. Further studies revealed that the modified electrode can be used for BOD measurement in a high‐salt condition. Also, the bacterium/CNTs biofilm can maintain its activity and good performance, even after being sealed and stored at 4°C for 50 days.
Diffusion Tensor Imaging Identifies Deficits in White Matter Microstructure in Subjects With Type 1 Diabetes That Correlate With Reduced Neurocognitive Function
Authors: Kodl Christopher T. , Franc Daniel T. , Rao Jyothi P. , Anderson Fiona S. , Thomas William , Mueller Bryon A. , Lim Kelvin O. , Seaquist Elizabeth R.
Published: August 2008

OBJECTIVE—Long-standing type 1 diabetes is associated with deficits on neurocognitive testing that suggest central white matter dysfunction. This study investigated whether diffusion tensor imaging (DTI), a type of magnetic resonance imaging that measures white matter integrity quantitatively, could identify white matter microstructural deficits in patients with long-standing type 1 diabetes and whether these differences would be associated with deficits found by neurocognitive tests.

RESEARCH DESIGN AND METHODS—Twenty-five subjects with type 1 diabetes for at least 15 years and 25 age- and sex-matched control subjects completed DTI on a 3.0 Tesla scanner and a battery of neurocognitive tests. Fractional anisotropy was calculated for the major white matter tracts of the brain.

RESULTS—Diabetic subjects had significantly lower mean fractional anisotropy than control subjects in the posterior corona radiata and the optic radiation (P < 0.002). In type 1 diabetic subjects, reduced fractional anisotropy correlated with poorer performance on the copy portion of the Rey-Osterreith Complex Figure Drawing Test and the Grooved Peg Board Test, both of which are believed to assess white matter function. Reduced fractional anisotropy also correlated with duration of diabetes and increased A1C. A history of severe hypoglycemia did not correlate with fractional anisotropy.

CONCLUSIONS—DTI can detect white matter microstructural deficits in subjects with long-standing type 1 diabetes. These deficits correlate with poorer performance on selected neurocognitive tests of white matter function.
Use of Pressure Offloading Devices in Diabetic Foot Ulcers
Authors: Wu Stephanie C. , Jensen Jeffrey L. , Weber Anna K. , Robinson Daniel E. , Armstrong David G.
Published: August 2008

OBJECTIVE—Pressure mitigation is crucial for the healing of plantar diabetic foot ulcers. We therefore discuss characteristics and considerations associated with the use of offloading devices.

RESEARCH DESIGN AND METHODS—A diabetic foot ulcer management survey was sent to foot clinics in all 50 states and the District of Columbia in 2005. A total of 901 geographically diverse centers responded. The survey recorded information regarding usage frequency and characteristics of assessment and treatment of diabetic foot ulcers in each center.

RESULTS—Of the 895 respondents who treat diabetic foot ulcers, shoe modifications (41.2%, P < 0.03) were the most common form of pressure mitigation, whereas total contact casts were used by only 1.7% of the centers.

CONCLUSIONS—This study reports the usage and characteristics of offloading devices in the care of diabetic foot ulcers in a broadly distributed geographic sample. Less than 2% of specialists use what has been termed the “gold standard” (total contact cast) for treating the majority of diabetic foot ulcers.
Nested (Ossifying) Stromal Epithelial Tumor of the Liver: Case Report
Authors: Meir Karen , Maly Alexander , Doviner Victoria , Gross Eitan , Weintraub Michael , Rabin Lionel , Pappo Orit
Published: August 2008

Nested stromal-epithelial tumor (NSET) of the liver is an extremely rare primary hepatic tumor with uncertain malignant potential. To date, only 11 cases have been described. We describe the case of a 2 1/2-year-old girl with an incidental liver mass. The mass was discovered on follow-up abdominal imaging for asymptomatic hydronephrosis diagnosed on antenatal ultrasound. Needle biopsy showed a mixed stromal and epithelial process in a nested pattern, with foci of ossification and no significant pleomorphism or necrosis. The nest cells stained with WT-1, cytokeratin 18, and CD56. Ossifying stromal epithelial tumor of the liver was strongly suspected. The findings were confirmed in the subsequent partial hepatectomy specimen. To our knowledge, this is the 12th case of NSET in the English-language literature and the 3rd case of NSET associated with genitourinary system abnormalities. Possible associations with dysregulated WT-1 expression are discussed.
Tensile behaviour of micro-sized copper wires studied using a novel fibre tensile module
Authors: Yang B. , Motz C. , Grosinger W. , Kammrath W. , Dehm G.
Published: August 2008

Tensile experiments on micro-sized polycrystalline copper wires with diameters ranging from 14 μm to 50 μm were performed using a recently developed fibre tensile module capable of high accuracy and flexibility. This module is able to fit into a scanning electron microscope for in-situ deformation studies. In this study the influence of the gauge length, wire diameter and grain size on the tensile properties is analysed. In-situ experiments performed in a scanning electron microscope revealed clearly that the occurrence of “pop-in” events in the load-displacement curves are related to slip. The results are compared to deformation studies of micro-sized copper samples in the literature and discussed taking in-situ scanning electron microscope observations into account.
Dislocation densities in soft and hard oriented grains of compression deformed textured NiAl polycrystals
Authors: Ungár Tamás , Nyilas Krisztián , Skrotzki Werner
Published: August 2008

NiAl polycrystals with different textures have been compressed at room temperature with and without confining pressure to strains of 6 and 30 %, respectively. Grain orientation dependent dislocation densities have been determined by X-ray line profile analysis using the multiple whole profile procedure. The dislocation density as well as the stored energy in hard grains, <100> oriented with respect to the compression axis, generally is about half of that in soft grains, which are randomly oriented. Taking into account appropriate individual dislocation contrast factors it has been found that in hard grains slip mainly takes place by <111> screw dislocations while in soft grains there is about a 50 % contribution of mixed type <100> dislocations. The results are discussed with respect to the inhomogeneity of deformation of plastically anisotropic materials and its effect on recrystallization.
Wear behavior of plasma nitrided AISI 420 stainless steel
Authors: Brühl Sonia P. , Charadia Raúl , Sanchez Carlos , Staia Mariana H.
Published: August 2008

Martensitic AISI 420 stainless steel was plasma nitrided using a DC N2 – H2 pulsed discharge, after thermal treatment at two different tempering temperatures. Sliding wear behavior was determined by means of a ball-on-disk tribometer at room temperature and without lubrication. Wear volume was calculated from the information provided by an optical profilometer and wear scars were analyzed by Scanning Electron Microscopy. The results indicated that the nitrided samples exhibited improved wear resistance when compared to the untreated specimens, but corrosion resistance was diminished due to the presence of the outer nitrided layer. However, when this layer was removed mechanically considerable improvement in the corrosion resistance was achieved without impairing the wear resistance of the whole system, which was 200 % higher compared to the wear resistance of the non-nitrided specimens.
Hot extrusion of α and α/β-brass alloys
Authors: Reetz Björn , Reimers Walter
Published: August 2008

The investigations aim at the control of the formability and the strength of hot extruded brass alloys through choosing the appropriate hot extrusion parameters. Different α-brass and α/β-brass alloys, namely CuZn10, CuZn20, CuZn37 and CuZn40Pb2, were hot extruded and subsequently investigated by means of microscopy, X-ray diffraction and mechanical testing.

The investigations show that the strength and formability of the extrudates are strongly affected by the hot extrusion parameters which determine the grain sizes and the textures of the extrudates. Additionally in the cases of CuZn37 and CuZn40Pb2, multiple phase transformations arise during the hot extrusion process and affect the resulting properties. The bcc β-phase content especially depends on the extrusion temperature, deformation degree and deformation rate.
Modeling of isothermal bainite formation based on the nucleation kinetics
Authors: van Bohemen Stefan M. C. , Sietsma Jilt
Published: August 2008

Using a new approach to modeling bainite nucleation, the kinetics of isothermal bainite formation have been calculated under the assumption of displacive growth. The nucleation rate is assumed to depend on the number density of potential nucleation sites N
i, a factor λ accounting for autocatalytic nucleation, and an activation energy Q*. Compatible with the theory for athermal martensite nucleation, N
i is assumed to be proportional to the driving pressure. Analogous to the Koistinen – Marburger model for martensite formation, the average volume of bainitic sub-units is assumed to be constant over the extent of the transformation and the growth of sub-units is very fast, and thus the change in fraction is directly related to the nucleation rate of bainite. The model results in an analytical expression for the fraction bainite as a function of time that contains only two adjustable parameters: a (temperature independent) autocatalytic parameter λ and a rate parameter κ, which has a temperature dependence that is mainly governed by Q*. The calculations are compared with experimental fraction curves measured isothermally with dilatometry for the carbon steels C45, C50 and C60 at a range of temperatures. From the best agreement between the calculations and the experimental data it follows that Q* decreases linearly with temperature, which is consistent with other bainite nucleation models. By austenitizing steel C60 at different temperatures it is found that λ depends on the austenite grain size: when the austenite grain size is increased, λ becomes larger.
Multi-scale mechanical characterization of a freestanding polymer film using indentation
Authors: Liu Kuo-Kang , Wan Kai-tak
Published: August 2008

A thin circular film is clamped at the periphery. An external mechanical force is applied to the film center via either a shaft with a spherical cap or a ball bearing with a specific weight. The deformed geometry allows the materials parameters of the film to be assessed for a wide range of length scales. Solid mechanics models are derived for a multi-scale deformation range as the film experiences (i) indentation or Hertzian contact, (ii) plate-bending, (iii) membrane-stretching, and (iv) large deformation. The method caters to ultrathin membranes where conventional macroscopic tensile tests might potentially damage the sample films. Thin film adhesion-delamination can also be characterized by the same set-up. Experiments were conducted for a range of polymer films.
Pop-in effect in Ge- and Si-coated single-crystalline Si
Authors: Nagy Péter M. , Vad Kálmán , Csik Attila , Kálmán Erika
Published: August 2008

In nanoindentation tests the pop-in effect is a sudden increase in penetration depth without an increase in load, caused by some special effect because of the smaller specific volume of the high-pressure phase in Si. It has been investigated in Si samples covered with 20, 50, 100 and 150 nm thick layers of amorphous Si or Ge in single and multiple load events. The impressions caused by the indentation were imaged by atomic force microscopy. The characteristics of the load curves and the shape of the indented impressions are correlated. Our experiments provide a consistent evaluation of the Young's modulus and hardness of the samples and consistent data on the exact shape of the indent impressions. The dependence of the variation of the magnitude and spatial distribution of the relaxed volume on the composition and thickness of the sputtered layer is discussed.
Mechanical and tribological behaviour of carbon nanotube brushes
Authors: Jarzącbek Dariusz , Rymuza Zygmunt , Wada Takenori , Ohmae Nobuo
Published: August 2008

Carbon nanotube brushes of micrometre range height were deposited on a silicon substrate and tested by use of atomic force microscopy. The cantilever's tips were made of silicon or steel. Firstly, the effect of the structure of carbon nanotubes on indentation (mechanical behaviour) in normal direction to the substrate was studied. Moreover, to examine nanotribological properties, sliding in the lateral direction to the substrate was studied. We also studied how the resonance frequency of vibration of one kind of microfork changes with the depth, to examine the connection between friction force and depth of the measurement. Finally, a mathematical model of the mechanical and tribological properties of carbon nanotube brushes was elaborated.
Measurement of the isothermal sections at 700 and 427 °C in the Al – Mg – Ni system
Authors: He Cuiyun , Du Yong , Chen Hai-Lin , Ouyang Hongwu
Published: August 2008

This work focuses on the experimental investigation of the ternary Al – Mg – Ni system at 700 and 427 °C by means of X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy and electron probe microanalysis. Only one ternary phase τ1 (Ni2Mg3Al) with a composition of about 15.5 at.% Al, 49.5 at.% Mg, and 35 at.% Ni was observed at both 700 and 427 °C. At 700 °C, the binary NiAl phase dissolves about 17 at.% Mg and the Ni2Mg phase dissolves up to about 10 at.% Al. At 427 °C, NiAl and Ni2Mg were found to dissolve the third element in appreciable quantities. Ni2Al3 was also observed dissolving up to about 2.5 at.% Mg. The isothermal sections at 700 and 427 °C are presented.
Genomic Analysis of the Snn1 Locus on Wheat Chromosome Arm 1BS and the Identification of Candidate Genes
Authors: Reddy Leela , Friesen Timothy L. , Meinhardt Steven W. , Chao Shiaoman , Faris Justin D.
Published: August 2008

The pathogen Stagonospora nodorum produces multiple host‐selective toxins (HSTs) that induce cell death and necrosis in sensitive wheat (Triticum sp.) genotypes. One such HST is SnTox1, which interacts with the host gene Snn1 on wheat chromosome arm 1BS to cause necrosis leading to disease susceptibility. Toward the positional cloning of Snn1, we developed saturated and high‐resolution maps of the Snn1 locus and evaluated colinearity of the region with rice (Oryza sativa L.). An F2 population of 120 individuals derived from ‘Chinese Spring’ (CS) and the CS–T. dicoccoides chromosome 1B disomic substitution line was used to map 54 markers consisting of restriction fragment length polymorphisms (RFLPs), simple sequence repeats, and bin mapped expressed sequence tags (ESTs). Colinearity between wheat 1BS and rice was determined by aligning EST and RFLP probe sequences to the rice genome. Overall, colinearity was poorly conserved due to numerous complex chromosomal rearrangements, and of 48 wheat EST‐RFLP sequences mapped, 30 had significant similarity to sequences on nine different rice chromosomes. However, 12 of the wheat sequences had similarity to sequences on rice chromosome 5 and were in a colinear arrangement with only a few exceptions, including an inversion of the markers flanking Snn1. High‐resolution mapping of the Snn1 locus in 8510 gametes delineated the gene to a 0.46‐cM interval. Two EST‐derived markers that cosegregated with Snn1 were found to share homology to nucleotide binding site–leucine rich repeat–like genes and are considered potential candidates for Snn1.
Compound heterozygous deletions of PMP22 causing severe Charcot‐Marie‐Tooth disease of the Dejerine‐Sottas disease phenotype
Authors: Al‐Thihli Khalid , Rudkin Teresa , Carson Nancy , Poulin Chantal , Melançon Serge , Der Kaloustian Vazken M.
Published: August 2008

Dejerine‐Sottas disease (DSD) is a particular phenotype of the Charcot‐Marie‐Tooth (CMT) disease spectrum that is genetically heterogeneous. It represents a severe form of hypertrophic axonal and demyelinating neuropathy. Although it is predominantly inherited as an autosomal recessive condition, autosomal dominant inheritance has also been described. To date, the autosomal recessive forms of DSD are classified into several CMT type 4 (CMT4) subclasses based on allelic heterogeneity. We present a 7‐year‐old boy with a severe form of CMT disease consistent with the autosomal recessive phenotype of DSD. He was found to be a compound heterozygote for mutations in the PMP22 gene resulting in homozygous deletion of exons 2 and 3. The maternally inherited allele was the typical 1.5 Mb deletion involving PMP22 seen with hereditary neuropathy with liability to pressure palsy (HNPP). The paternally inherited allele was a deletion of exons 2 and 3. Both parents presented with a typical clinical picture of HNPP. To our knowledge, this is the first patient reported with large deletions involving both PMP22 alleles. Our patient has also developed severe gastroesophageal reflux disease (GERD), a clinical feature not previously reported with CMT or DSD. The correlation of the phenotype and the molecular defects observed in this patient may set a new subcategory in the classification of DSD. © 2008 Wiley‐Liss, Inc.
Novel subtype of congenital generalized lipodystrophy associated with muscular weakness and cervical spine instability
Authors: Simha Vinaya , Agarwal Anil K. , Aronin Patricia A. , Iannaccone Susan T. , Garg Abhimanyu
Published: August 2008

Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder characterized by extreme paucity of adipose tissue from birth, and early onset of metabolic complications related to insulin resistance. Mutations in three genes, 1‐acylglycerol 3‐phosphate‐O‐acyltransferase 2 (AGPAT2), Berardinelli Seip Congenital Lipodystrophy 2 (BSCL2), and Caveolin‐1 (CAV1) are associated with the three subtypes of this disorder, CGL1, CGL2 and CGL3, respectively. We report two siblings of Hispanic origin who displayed characteristic features of CGL such as generalized loss of subcutaneous fat from birth, acanthosis nigricans, acromegaloid habitus, umbilical prominence, hepatosplenomegaly, hypoleptinemia, dyslipidemia, and insulin resistance. However, no disease causing variants were detected in the DNA sequence of AGPAT2, BSCL2 or CAV1 genes. Further, whole body magnetic resonance imaging (MRI) in the two siblings revealed marked loss of subcutaneous, intraabdominal and intrathoracic fat like in other patients with CGL, but preservation of bone marrow fat which is invariably lost in all patients with CGL1 and CGL2, but not in the patient reported with CGL3. They also had generalized muscle weakness during infancy and early childhood associated with a nearly fivefold increase in serum creatine kinase (CK) levels, but with normal muscle biopsy and electrophysiologic studies. Both patients were also found to have atlantoaxial dislocation requiring surgical intervention. Thus, this pedigree represents a novel subtype of CGL characterized by generalized loss of body fat but with preservation of bone marrow fat, congenital muscular weakness and cervical spine instability. The genetic basis of this novel subtype remains to be determined. © 2008 Wiley‐Liss, Inc.
Spondyloepiphyseal dysplasia, Omani type: Further definition of the phenotype
Authors: van Roij Mirjam H.H. , Mizumoto Shuji , Yamada Shuhei , Morgan Tim , Tan‐Sindhunata M.B. , Meijers‐Heijboer H. , Verbeke J.I.L.M. , Markie David , Sugahara Kazuyuki , Robertson Stephen P.
Published: August 2008

Spondyloepiphyseal dysplasia (SED), Omani type (OMIM 608637) is a recessively inherited skeletal dysplasia previously described in two distantly related families from the Republic of Oman. The phenotype consists of short stature, severe kyphoscoliosis, arthritic joints (elbows, wrists, knees), secondary large joint dislocations, rhizomelia, fusion of carpal bones and mild brachydactyly. Affected individuals were homozygous for a missense mutation, R304Q in CHST3 that encodes the enzyme chondroitin 6‐O‐sulfotransferase‐1 (C6ST‐1). This enzyme mediates the sulfation of proteoglycans, particularly chondroitin sulfate (CS), in the extracellular matrix of cartilage. Here we describe the identification of a mutation (857T > C predicting the substitution L286P) in CHST3 in a Turkish family and extend the clinical phenotype of SED‐Omani type to include congenital joint dislocation, club feet, ventricular septal defect, deafness, metacarpal shortening and accessory carpal ossification centers. Fibroblasts and urine obtained from affected patients demonstrated negligible levels of 6‐O‐sulfated GalNAc residue in CS. Furthermore, the 6‐O‐sulfotransferase activity of cloned C6ST‐1 into which the L286P mutation had been introduced was dramatically reduced, confirming the pathogenicity of this substitution. These results indicate that the clinical consequences of a deficiency of 6‐O‐sulfation in CS can be varied and that a clinical spectrum may exist similar to that seen in other skeletal dysplasias characterized by disorders of proteoglycan sulfation. © 2008 Wiley‐Liss, Inc.
Candidate region linkage analysis in twins discordant or concordant for depression symptomatology
Authors: Christiansen L. , Tan Q. , Kruse T.A. , McGue M. , Christensen K.
Published: August 2008

Genetic risk factors contribute considerably to both clinical affective disorders and subsyndromal mood level. There is moreover evidence to suggest that the genetic basis of bipolar disorder and unipolar depression overlap to some extent, and several linkage analyses have suggested evidence for a common susceptibility locus in affective disorders on chromosome 12q24. In this study we investigated the chromosome 12 candidate region for linkage to the mean level of depression symptomatology, over a 10‐year follow‐up, using a highly informative sample of concordant and discordant twin pairs selected from 4,731 participants of the Longitudinal Study of Ageing Danish Twins. Our results showed suggestive evidence of linkage to this region with a peak LOD score of 1.91 for marker D12S1634 located at 148 cM, and thus indicates that the previously identified disease locus at 12q24 is also a general vulnerability locus affecting the normal range of mood. © 2008 Wiley‐Liss, Inc.
Novel pyridine‐bis(ferrocene‐isoxazole) ligand: synthesis and application to palladium‐catalyzed Sonogashira cross‐coupling reactions under copper‐ and phosphine‐free conditions
Authors: Feng Zhijun , Yu Shuyan , Shang Yongjia
Published: August 2008

We present here the first synthesis and application to Sonogashira reaction of pyridine‐bis(ferrocene‐isoxazole) Pd(II) complex 5, prepared from 2,6‐bis‐(5‐ferrocenylisoxazole‐3‐yl)pyridine. Under copper‐ and phosphine‐free conditions, the stable complex 5 efficiently catalyzed the cross‐coupling of aryl halides with terminal alkynes in DMF–H2O with TBAB as an additive, hexahydropyridine as base and affording internal arylated alkynes in moderate to excellent yields. Copyright © 2008 John Wiley & Sons, Ltd.
Mechanical and morphological properties of epoxy resins modified by poly(phthalazinone ether sulfone ketone)
Authors: Xu Yajuan , Liao Gongxiong , Gu Tiesheng , Zheng Liang , Jian Xigao
Published: August 2008

A series of blends have been prepared by adding a novel thermoplastic poly(phthalazinone ether sulfone ketone) (PPESK) in varying proportions to diglycidyl ether of bisphenol A epoxy resin (DGEBA) cured with p‐diaminodiphenylsulfone (DDS). All the blends showed two‐phase structures characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Addition of the PPESK resulted in great enhancement of glass transition temperatures (Tg) both in the epoxy‐rich phase and in the PPESK‐rich phase by reason of the special structure of PPESK. There was moderate increase in the fracture toughness as estimated by impact strength. Fracture mechanisms such as crack deflection and branches, ductile microcracks, ductile tearing of the thermoplastic, and local plastic deformation of the matrix were responsible for the increase in the fracture toughness of the blends. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Grafting of maleic anhydride onto polyethylene through a green chemistry approach
Authors: Shen Yanhan , Qi Rongrong , Liu Qiaochu , Wang Yanling , Mao Yapeng , Yu Juan
Published: August 2008

The grafting of a polymer can lead to the improvement and modification of the polymer and thus expand its applications. Grafting methods include solution grafting in organic solvents, melt grafting at high temperatures, and light grafting with radioactive sources. These methods have their advantages and disadvantages. The disadvantages include waste treatment, consumption of energy, and so on. In this study, a hydrothermal process which is called the green approach, was developed to prepare graft copolymers. The effect of various factors on the grafting degree was investigated in detail. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Sexual devolution in plants: apomixis uncloaked?
Authors: Noyes Richard D.
Published: August 2008

There are a growing number of examples where naturally occurring mutations disrupt an established physiological or developmental pathway to yield a new condition that is evolutionary favored. Asexual reproduction by seed in plants, or apomixis, occurs in a diversity of taxa and has evolved from sexual ancestors. One form of apomixis, diplospory, is a multi‐step development process that is initiated when meiosis is altered to produce an unreduced rather than a reduced egg cell. Subsequent parthenogenetic development of the unreduced egg yields genetically maternal progeny. While it has long been apparent from cytological data that meiosis in apomicts was malfunctional or completely bypassed, the genetic basis of the phenomenon has been a long‐standing mystery. New data from genetic analysis of Arabidopsis mutants1 in combination with more sophisticated molecular understanding of meiosis in plants indicate that a weak mutation of the gene SWI, called DYAD, interferes with sister chromatid cohesion in meiosis I, causes synapsis to fail in female meiosis and yields two unreduced cells. The new work shows that a low percentage of DYAD ovules produce functional unreduced egg cells (2n) that can be fertilized by haploid pollen (1n) to give rise to triploid (3n) progeny. While the DYAD mutants differ in some aspects from naturally occurring apomicts, the work establishes that mutation to a single gene can effectively initiate apomictic development and, furthermore, focuses efforts to isolate apomixis genes on a narrowed set of developmental events. Profitable manipulation of meiosis and recombination in agronomically important crops may be on the horizon. BioEssays 30:798–801, 2008. © 2008 Wiley Periodicals, Inc.
Involvement of IL‐2 in homeostasis of regulatory T cells: the IL‐2 cycle
Authors: Yarkoni Shai , Kaminitz Ayelet , Sagiv Yuval , Yaniv Isaac , Askenasy Nadir
Published: August 2008

A large body of evidence on the activity of regulatory T (Treg) cells was gathered during the last decade, and a similar number of reviews and opinion papers attempted to integrate the experimental findings. The abundant literature clearly delineates an exciting area of research but also underlines some major controversies. A linear cause–result interpretation of experimental maneuvers often ignores the fact that the activity of Treg cells is orchestrated with the effector T (Teff) cells within an intricate network of physiological immune homeostasis. Every modulation of the activity of the effector (cytotoxic) immune system revolves to affect the activity of regulatory (suppressive) cells through elaborate feedback loops of negative and positive regulation. The lack of IL‐2 production by innate Treg cells makes this cytokine a prime coupler of the effector and suppressive mechanisms. Here we attempt to integrate evidence that delineates the involvement of IL‐2 in primary and secondary feedback loops that regulate the activity of suppressive cells within the elaborate network of physiological immune homeostasis.©2007 Wiley Periodicals, Inc BioEssays 30:875–888, 2008. © 2008 Wiley Periodicals, Inc.
The Impact of Weak CH⋅⋅⋅Rh Interactions on the Structure and Reactivity of trans‐[Rh(CO)2(phosphine)2]+: An Experimental and Theoretical Examination
Authors: Montag Michael , Efremenko Irena , Cohen Revital , Leitus Gregory , Shimon Linda J. W. , Diskin‐Posner Yael , Ben‐David Yehoshoa , Martin Jan M. L. , Milstein David
Published: August 2008

The crystal structure of the new cationic RhI complex trans‐[Rh(CO)2(L)2]BF4 (L=α2‐(diisopropylphosphino)isodurene) was found to exhibit a nonlinear OCRhCO fragment and weak intramolecular CH⋅⋅⋅Rh interactions. These interactions, which have also been shown to occur in solution, have been examined by density functional theory calculations and found to be inextricably linked to the presence of the distorted OCRhCO fragment. This linkage has also been demonstrated by comparison with a highly similar RhI complex, in which these CH⋅⋅⋅Rh interactions are absent. Furthermore, the presence of these weak interactions has been shown to have a significant effect on the reactivity of the metal center.
ChemInform Abstract: Crystal Structure of the Ln3Si1.25Se7 (Ln: Pr, Nd and Sm) Compounds.
Authors: Gulay L. D. , Lychmanyuk O. S.
Published: August 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: High‐Pressure/High‐Temperature Studies on the Stannides RENiSn (RE: Ce, Pr, Nd, Sm) and REPdSn (RE: La, Pr, Nd).
Authors: Riecken Jan F. , Heymann Gunter , Hermes Wilfried , Rodewald Ute Ch. , Hoffmann Rolf‐Dieter , Huppertz Hubert , Poettgen Rainer
Published: August 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Magnetism, Magnetotransport and Magnetic Structure of ThCu3Mn4O12, Prepared at Moderate Pressures.
Authors: Sanchez‐Benitez Javier , Martinez‐Lope Maria J. , Alonso Jose A.
Published: August 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.