bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial distribution of transcript changes in the maize primary root elongation zone at low water potential
Authors: Spollen William G , Tao Wenjing , Valliyodan Babu , Chen Kegui , Hejlek Lindsey G , Kim Jong-Joo , LeNoble Mary E , Zhu Jinming , Bohnert Hans J , Henderson David , Schachtman Daniel P , Davis Georgia E , Springer Gordon K , Sharp Robert E , Nguyen Henry T 
Published: April 2008

Abstract

Background
Previous work showed that the maize primary root adapts to low Ψw (-1.6 MPa) by maintaining longitudinal expansion in the apical 3 mm (region 1), whereas in the adjacent 4 mm (region 2) longitudinal expansion reaches a maximum in well-watered roots but is progressively inhibited at low Ψw. To identify mechanisms that determine these responses to low Ψw, transcript expression was profiled in these regions of water-stressed and well-watered roots. In addition, comparison between region 2 of water-stressed roots and the zone of growth deceleration in well-watered roots (region 3) distinguished stress-responsive genes in region 2 from those involved in cell maturation.

Results
Responses of gene expression to water stress in regions 1 and 2 were largely distinct. The largest functional categories of differentially expressed transcripts were reactive oxygen species and carbon metabolism in region 1, and membrane transport in region 2. Transcripts controlling sucrose hydrolysis distinguished well-watered and water-stressed states (invertase vs. sucrose synthase), and changes in expression of transcripts for starch synthesis indicated further alteration in carbon metabolism under water deficit. A role for inositols in the stress response was suggested, as was control of proline metabolism. Increased expression of transcripts for wall-loosening proteins in region 1, and for elements of ABA and ethylene signaling were also indicated in the response to water deficit.

Conclusion
The analysis indicates that fundamentally different signaling and metabolic response mechanisms are involved in the response to water stress in different regions of the maize primary root elongation zone.
Interaction between the C-terminal region of human myelin basic protein and calmodulin: analysis of complex formation and solution structure
Authors: Majava Viivi , Petoukhov Maxim V , Hayashi Nobuhiro , Pirilä Päivi , Svergun Dmitri I , Kursula Petri 
Published: April 2008

Abstract

Background
The myelin sheath is a multilamellar membrane structure wrapped around the axon, enabling the saltatory conduction of nerve impulses in vertebrates. Myelin basic protein, one of the most abundant myelin-specific proteins, is an intrinsically disordered protein that has been shown to bind calmodulin. In this study, we focus on a 19-mer synthetic peptide from the predicted calmodulin-binding segment near the C-terminus of human myelin basic protein.

Results
The interaction of native human myelin basic protein with calmodulin was confirmed by affinity chromatography. The binding of the myelin basic protein peptide to calmodulin was tested with isothermal titration calorimetry (ITC) in different temperatures, and Kd was observed to be in the low μM range, as previously observed for full-length myelin basic protein. Surface plasmon resonance showed that the peptide bound to calmodulin, and binding was accompanied by a conformational change; furthermore, gel filtration chromatography indicated a decrease in the hydrodynamic radius of calmodulin in the presence of the peptide. NMR spectroscopy was used to map the binding area to reside mainly within the hydrophobic pocket of the C-terminal lobe of calmodulin. The solution structure obtained by small-angle X-ray scattering indicates binding of the myelin basic protein peptide into the interlobal groove of calmodulin, while calmodulin remains in an extended conformation.

Conclusion
Taken together, our results give a detailed structural insight into the interaction of calmodulin with a C-terminal segment of a major myelin protein, the myelin basic protein. The used 19-mer peptide interacts mainly with the C-terminal lobe of calmodulin, and a conformational change accompanies binding, suggesting a novel mode of calmodulin-target protein interaction. Calmodulin does not collapse and wrap around the peptide tightly; instead, it remains in an extended conformation in the solution structure. The observed affinity can be physiologically relevant, given the high abundance of both binding partners in the nervous system.
Mosquito larvicidal activities of Solanum villosum berry extract against the dengue vector Stegomyia aegypti
Authors: Chowdhury Nandita , Ghosh Anupam , Chandra Goutam 
Published: April 2008

Abstract

Background
Vector control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. Although several plants have been reported for mosquitocidal activity, only a few botanicals have moved from the laboratory to field use, because they are poorly characterized, in most cases active principals are not determined and most of the works are restricted to preliminary screening. Solanum villosum is a common weed distributed in many parts of India with medicinal properties, but the larvicidal activity of this plant has not been reported so far.

Methods
Aqueous and polar/non-polar solvent extract of fresh, mature, green berries of S. villosum was tested against Stegomyia aegypti, a common vector of dengue fever. A phytochemical analysis of chloroform:methanol extract was performed to search for the active toxic ingredient. The lethal concentration was determined (log probit analysis) and compared with Malathion. The chemical nature of the active substance was also evaluated following ultraviolet-visual (UV-Vis) and infrared (IR) analysis.

Results
In a 72 hour bioassay experiment with the aqueous extract, the highest mortality was recorded in 0.5% extract. When the mortality of different solvent extracts was compared, the maximum (p < 0.05) mortality was recorded at a concentration of 50 ppm of chloroform:methanol extract (1:1, v/v). The larvicidal activity was lower when compared with the chemical insecticide, Malathion (p < 0.05). Results of regression analysis revealed that the mortality rate (Y) was positively correlated with the period of exposure (X) and the log probit analysis (95% confidence level) recorded lowest value (5.97 ppm) at 72 hours of exposure. Phytochemical analysis of the chlororm:methanol extract reported the presence of many bioactive phytochemicals. Two toxic compounds were detected having R
f = 0.82 (70% and 73.33% mortality in 24 and 48 hours, respectively) and R
f = 0.95 (40% and 50% mortality in 24 and 48 hours, respectively). IR analysis provided preliminary information about the steroidal nature of the active ingredient.

Conclusion

S. villosum offers promise as potential bio control agent against S. aegypti particularly in its markedly larvicidal effect. The extract or isolated bioactive phytochemical could be used in stagnant water bodies for the control of mosquitoes acting as vector for many communicable diseases.
A case of spotted fever group rickettsiosis imported into the United Kingdom and treated with ciprofloxacin: a case report
Authors: Rashid Rifat , Pasqualotto Alessandro C , Denning David W 
Published: April 2008

Abstract

Introduction
Spotted fever group rickettsioses are an interesting group of infections, which are increasing in incidence worldwide.

Case presentation
Here we describe an imported case to the United Kingdom occurring in a patient who had recently visited Kruger National Park in South Africa – a highly endemic area for Rickettsia infections. Initial treatment with doxycycline failed but the patient made a prompt recovery after commencement of ciprofloxacin.

Conclusion
This finding raises the possibility that there are resistant strains of Rickettsia present.
Experimental study on sheet metal bending with medium-power diode laser
Authors: Chen M-L , Jeswiet J , Bates P J , Zak G 
Published: April 2008

In an experimental study of laser sheet bending, a 160 W diode laser is used for two-dimensional sheet bending of low-carbon steel. The variables investigated include metal sheet thickness, laser scan speed, laser power, laser beam width, and laser scan pass number. Bend surface appearances are also analysed. The laser sheet bend results demonstrate that a 940 Nm diode laser is an effective tool for laser forming of carbon steel sheets. No additional surface coating was required. The buckling mechanism may be the main source contributing to the large angle of bend found for the laser-beam-width to sheet-thickness aspect ratio close to 4; for a laser-beam-width to sheet-thickness aspect ratio of less than 2, both temperature gradient and buckling mechanisms contributed to the lower bend angles. The laser beam width study showed that, for the given material thickness range and laser beam profile, the maximum bend angle depends mainly on the material thickness, not the power intensity distribution across the bend line. However, a more evenly distributed laser beam gave the same bend angle with less material property and surface appearance changes. For obtaining the same bend angle, less laser line energy was required if a higher laser scan speed was applied, except for the extreme high-line energy level. Also, multi-path bend strategies may be preferred for maximizing the total bend angle as well as reducing bend surface morphology changes.
Evaluation of environmentally conscious manufacturing programs using multiple attribute decision-making methods
Authors: Rao R V 
Published: April 2008

Manufacturers are increasingly under pressure from their major stakeholders to integrate environmental issues in the design and management of their products. These stakeholders include customers, regulators, employees, communities, and interest groups who have a common stake in protecting the earth from pollution and in limiting the exploitation of earth's limited natural resources. Manufacturers recognize that being environmentally responsible also offers competitive advantage to the firm. An environmentally responsible or environmentally conscious manufacturing (ECM) program addresses the environmental impact of the interrelated decisions that are made at various stages of product life, from conception to design, raw materials consumption, processing, delivery, use, recycling, and/or disposal. The evaluation of alternative ECM programs for producing a given product is similar to many strategic initiatives and their justification methodologies. This similarity arises from the fact that there are multiple attributes that need to be considered, many of which have long-term and broad implications for an organization. This paper presents three multiple attribute decision-making methods for evaluation of environmentally conscious manufacturing (ECM) programs for producing a given product. These methods are based on the analytic hierarchy process (AHP), the technique for order preference by similarity to an ideal solution (TOPSIS), and the modified TOPSIS method. The proposed ‘ECM program selection index’ helps to evaluate and rank the ECM programs for producing a given product. An example is included to illustrate and compare the methods. It is proposed that the most sensible approach to select a particular alternative ECM program from among the given alternatives is to apply several valid decision-making methods to the same selection problem and then to make the final selection on the basis of aggregation of the results of those decision-making methods that have a very significant positive relationship.
Effect of powder mix composition on Al foam morphology
Authors: Costanza G , Gusmano G , Montanari R , Tata M E , Ucciardello N 
Published: April 2008

The effect of mix composition on foam morphology has been examined by image analysis carried out on metallographic sections of Al foams prepared by powder metallurgy. Two sets of samples have been prepared by using SiC particles with mean sizes of 37 and 60 µm. Each set consists of 16 groups of samples with different amounts of TiH2 (0.1, 0.2, 0.4, and 0.6 wt%) and SiC (0.8, 2.8, 6, and 9 wt%). The distribution of SiC particles on the internal walls of the bubbles has been investigated by scanning electron microscopy observations, which evidenced also the presence of particles of another phase, identified as Ti3Al by energy dispersion spectroscopy. Some tests, performed without SiC particles, showed that the Al foaming occurs also under these conditions, however foams exhibit few bubbles of very large size and irregular shape. Experimental data have been used for training two multi-layer feedforward artificial neural networks. The models represent useful tools for predicting morphologic features of foams for any given mix composition in the training range.
Effect of flexural stiffness estimates on the buckling load of delaminated composite beams
Authors: C W Yap. , Chai G. B. , Parlapalli M. S R. 
Published: April 2008

A closed-form expression to determine the effective flexural modulus for a laminated composite beam is derived and presented in this paper. An approach based on the established Euler—Bernoulli beam theory with the proposed effective flexural modulus to predict the buckling load of the laminated composite beam is also presented in detail. The problem of a laminated beam with no delamination and that with a single through-the-width delamination is analysed. The results obtained using the current expression are compared with those obtained using existing expressions found in the literature. Results from a non-linear finite-element analysis are also presented and included in the comparison. The parameters investigated include ply orientation, number of layers, delamination length, support conditions, and material property. The comparison of results showed that the current estimated effective flexural stiffness expression yields a good lower bound solution for predicting the buckling load of both the perfect and the delaminated laminated composite beam.
EIT Oedometer: An Advanced Cell to Monitor Spatial and Time Variability in Soil with Electrical and Seismic Measurements
Authors: Comina C. , Foti S. , Musso G. , Romero E. 
Published: April 2008

Abstract
The paper presents an innovative oedometer cell (EIT oedometer), accomplishing for monitoring the spatial and temporal evolution of different physical quantities inside soil samples through seismic and electric non-destructive measurements. The technical solutions implemented to perform correct electrical measurements are reported together with the results of benchmark tests demonstrating the potentialities and the limits of the 3D electrical resistivity tomography in detecting both pre-existing and induced sample heterogeneities. It is shown that resistivity imaging can offer a powerful tool for the investigation of soil heterogeneities not detected by external measurements. The relationship between electrical resistivity and soil properties makes this application potentially useful for monitoring the evolution of transient processes as for instance those related to the diffusion of chemical species in clay soils and associated coupled chemo-mechanical processes, whereas the information gathered by classical oedometer measurements and by seismic waves propagation could be used to explore the associated macroscopic phenomena.
Double Watermarking and Turbo Coding for Robust Image Watermarking
Authors: Chemak Chokri , Bouhlel Mohamed Salim , Lapayre Jean Christophe 
Published: April 2008

Abstract
This paper is an attempt to describe the concept of double watermarking. The latter term refers to a new watermarking scheme based on embedding a mark (signature) in both spatial and multiresolution domains. This scheme is able of embedding 2000 bits of mark in medical images with dimensions 256 by 256 pixels. Experiments on a database of 30 medical images indicate the watermarks are robust to noises, filter attacks, JPEG compression, and cropping. For the purpose of increasing the image watermarking robustness against attacks of an image transmission and to perform a large number of bits to hide into images we encode with a turbo code an image-embedded mark. Fidelity of images is improved by incorporation of the relative peak signal-to-noise ratio as a perceptual metric to measure image degradation. We demonstrate by some experimental results that this unit of measurement is the best distortion metric which is correlated with the human visual system to evaluate the quality of images after the watermarking process. We show that each of these three components improves performance substantially.
Measurements with a New Peel Adhesion Test on Waterproof Membranes Used on Concrete Bridge Decks
Authors: Zhou Qinghua , Xu Qinwu , Zhang Zhanjun 
Published: April 2008

Abstract
Interface adhesion is one of the critical performance criteria to evaluate the engineering properties of the waterproof membrane (WM) used on concrete bridge decks. The standardized methods such as the ones specified by ASTM have provided guidance to conduct interface adhesion tests. However, these methods are not specially designed for a WM used on concrete bridge decks, and ASTM D3359 is a qualitative test for evaluation of peel strength. Meanwhile, the interface adhesion is affected by a myriad of sophisticated field conditions. Accordingly, this research investigates the interface adhesion strength of the WM using a new 90° peel test. Laboratory and field tests were conducted in which the influences of peeling speed, use of subcoat, and construction temperature were taken into account. The four-point bending fatigue test on a WM was designed to account for the influences of repeated vehicle loadings on adhesion strength. Test results indicate that peel strength increases with increasing peeling speed, while it increases initially and then decreases with increasing the construction temperature of the WM and the content of subcoat. It is also found that peel strength has a linear log-log relationship with fatigue loading cycles.
Cadmium, lead, and mercury levels in feathers of small passerine birds: Noninvasive sampling strategy
Authors: Bianchi Nicola , Ancora Stefania , di Fazio Noemi , Leonzio Claudio 
Published: April 2008

Abstract
Bird feathers have been widely used as a nondestructive biological material for monitoring heavy metals. Sources of metals taken up by feathers include diet (metals are incorporated during feather formation), preening, and direct contact with metals in water, air, dust, and plants. In the literature, data regarding the origin of trace elements in feathers are not univocal. Only in the vast literature concerning mercury (as methyl mercury) has endogenous origin been determined. In the present study, we investigate cadmium, lead, and mercury levels in feathers of prey of Falco eleonorae in relation to the ecological characteristics (molt, habitat, and contamination by soil) of the different species. Cluster analysis identified two main groups of species. Differences and correlations within and between groups identified by cluster analysis were then checked by nonparametric statistical analysis. The results showed that mercury levels had a pattern significantly different from those of cadmium and lead, which in turn showed a significant positive correlation, suggesting different origins. Nests of F. eleonorae proved to be a good source for feathers of small trans-Saharan passerines collected by a noninvasive method. They provided abundant feathers of the various species in a relatively small area— in this case, the falcon colony on the Isle of San Pietro, Sardinia, Italy.
Toxicity and bioavailability of copper nanoparticles to the terrestrial plants mung bean (Phaseolus radiatus) and wheat (Triticum aestivum): Plant agar test for water-insoluble nanoparticles
Authors: Lee Woo-Mi , An Youn-Joo , Yoon Hyeon , Kweon Hee-Seok 
Published: April 2008

Abstract
Because of their insolubility in water, nanoparticles have a limitation concerning toxicity experiments. The present study demonstrated a plant agar test for homogeneous exposure of nanoparticles to plant species. The effect of Cu nanoparticles on the growth of a plant seedling was studied, and bioaccumulation of nanoparticles was investigated. All tests were conducted in plant agar media to prevent precipitation of water-insoluble nanoparticles in test units. The plant species were Phaseolus radiatus (mung bean) and Triticum aestivum (wheat). Growth inhibition of a seedling exposed to different concentrations of Cu nanoparticles was examined. Copper nanoparticles were toxic to both plants and also were bioavailable. The 2-d median effective concentrations for P. radiatus and T. aestivum exposed to Cu nanoparticles were 335 (95% confidence level, 251–447) and 570 (450–722) mg/L, respectively. Phaseolus radiatus was more sensitive than T. aestivum to Cu nanoparticles. A cupric ion released from Cu nanoparticles had negligible effects in the concentration ranges of the present study, and the apparent toxicity clearly resulted from Cu nanoparticles. Bioaccumulation increased with increasing concentration of Cu nanoparticles, and agglomeration of particles was observed in the cells using transmission-electron microscopy–energy-dispersive spectroscopy. The present study demonstrated that the plant agar test was a good protocol for testing the phytotoxicity of nanoparticles, which are hardly water soluble.
Groups and Algebras of Binary Relations
Authors: Givant Steven , Andréka Hajnal 
Published: April 2008

AbstractIn 1941, Tarski published an abstract, finitely axiomatized version of the theory of binary relations, called the theory of relation algebras. He asked whether every model of his abstract theory could be represented as a concrete algebra of binary relations. He and Jónsson obtained some initial, positive results for special classes of abstract relation algebras. But Lyndon showed, in 1950, that in general the answer to Tarski's question is negative. Monk proved later that the answer remains negative even if one adjoins finitely many new axioms to Tarski's system. In this paper we describe a far-reaching generalization of the positive results of Jónsson and Tarski, as well as of some later, related results of Maddux. We construct a class of concrete models of Tarski's axioms—called coset relation algebras—that are very close in spirit to algebras of binary relations, but are built using systems of groups and cosets instead of elements of a base set. The models include all algebras of binary relations, and many non-representable relation algebras as well. We prove that every atomic relation algebra satisfying a certain measurability condition—a condition generalizing the conditions imposed by Jónsson and Tarski—is essentially isomorphic to a coset relation algebra. The theorem raises the possibility of providing a positive solution to Tarski's problem by using coset relation algebras instead of the standard algebras of binary relations.
Fixed Point Logics
Authors: Dawar Anuj , Gurevich Yuri 
Published: April 2008

AbstractWe consider fixed point logics, i.e., extensions of first order predicate logic with operators defining fixed points. A number of such operators, generalizing inductive definitions, have been studied in the context of finite model theory, including nondeterministic and alternating operators. We review results established in finite model theory, and also consider the expressive power of the resulting logics on infinite structures. In particular, we establish the relationship between inflationary and nondeterministic fixed point logics and second order logic, and we consider questions related to the determinacy of games associated with alternating fixed points.