bluuebunny/crossref_metadata_2025 huggingface dataset:
Motion Capture in Golf
Authors: Wright Ian
Published: September 2008

Motion capture has been used extensively to study the golf swing in the laboratory. As motion capture technology has become more sophisticated and less expensive, the number of research studies has increased as has the scope of these research studies. Motion capture technology has become so accessible that it is now being used outside of the laboratory for golf instruction, coaching and club fitting. The use of this technology can enhance the teaching or club fitting experience, and will likely lead to increased understanding of the biomechanics of the golf swing
Long-Distance Interval Training following Pre-Cooling with an Ice Vest
Authors: Tegeder Andrew R. , Hunter Iain , Mack Gary W. , Hager Ron
Published: September 2008

This study evaluated how preparing for an interval workout, while wearing a cooling vest, affects core temperature (Tc), heart rate (HR), and interval time in long-distance runners. Nineteen male collegiate cross-country runners exercised under two different conditions: (a) wearing a Nike PreCool™ ice vest for one hour prior to the workout (30 minutes resting with the vest and 30 minutes while performing their warm-up); and (b) a control condition utilizing a traditional warm-up. Subjects performed 8 × 1000 m intervals. HR and Tc were measured prior to warm-up, immediately before the first interval, and after each interval. Tc measured before the first interval was significantly lower in the vest condition (difference = 0.37° ± 0.2°C). Differences persisted through the sixth interval. Differences in HR and interval times were nonsignificant between conditions for all intervals Wearing an ice vest prior to and during warm-up effectively lowers Tc during long-distance interval training.
Fractal Image Compression on Hexagonal Structure
Authors: Wang Huaqing , He Xiangjian , Hintz Tom , Wu Qiang
Published: September 2008

Fractal image compression (FIC) is a relatively recent image compression method. Its basic idea is to represent images as a fixed point of a contractive Iterated Function System (IFS). Spiral Architecture (SA) is a novel hexagonal image structure on which images are displayed as a collection of hexagonal pixels. The efficiency and accuracy of image processing on SA have been demonstrated in many recently published papers. In this paper, two presentations of SA on the traditional display device will be discussed. Then we will review the current research work on fractal image compression based on SA using both presentations. The FIC performance on SA will be compared with it on the traditional square structure in terms of compression ratio and PSNR. In the experimental results, higher PSNR values can be achieved at various compression ratios for all test images. The preliminary research on this direction has shown a promising future of applying FIC on SA to further improve the compression performance.
Image Denoise by Fourth-Order PDE Based on the Changes of Laplacian
Authors: Lŭ Lan , Wang Meiqing , Laib Choi-Hong
Published: September 2008

Fourth-order partial differential equation (PDE) proposed by You and Kaveh (You-Kaveh fourth-order PDE), which replaces the gradient operator in classical second-order nonlinear diffusion methods with a Laplacian operator, is able to avoid blocky effects often caused by second-order nonlinear PDEs. However, the equation brought forward by You and Kaveh tends to leave the processed images with isolated black and white speckles. Although You and Kaveh use median filters to filter these speckles, median filters can blur the processed images to some extent, which weakens the result of You-Kaveh fourth-order PDE. In this paper, the reason why You-Kaveh fourth-order PDE can leave the processed images with isolated black and white speckles is analyzed, and a new fourth-order PDE based on the changes of Laplacian (LC fourth-order PDE) is proposed and tested. The new fourth-order PDE preserves the advantage of You-Kaveh fourth-order PDE and avoids leaving isolated black and white speckles. Moreover, the new fourth-order PDE keeps the boundary from being blurred and preserves the nuance in the processed images, so, the processed images look very natural.
An Algorithm for Total Variation Inpainting Based on Nonlinear Multi-Grid Methods
Authors: Fei Chen , Mei-Qing Wang , Choi-Hong Lai
Published: September 2008

Image inpainting refers to restoring a damaged image with missing information. The total variation (TV) inpainting model is one such method that simultaneously fills in the regions with available information from their surroundings and eliminates noises. The method works well with small narrow inpainting domains. However there remains an urgent need to develop fast iterative solvers, as the underlying problem sizes are large. In addition one needs to tackle the imbalance of results between inpainting and denoising. When the inpainting regions are thick and large, the procedure of inpainting works quite slowly and usually requires a significant number of iterations and leads inevitably to oversmoothing in the outside of the inpainting domain. To overcome these difficulties, we propose a solution for TV inpainting method based on the nonlinear multi-grid algorithm.
Evaluation and Enhancement on Medical Images
Authors: Sun Lei , Wang Changying , Wang Shuyan
Published: September 2008

Objective: The aim of the paper is to study enhancement algorithm on mammograms, and quantitative measures of contrast enhancement. Method: The gray uniformity is defined by edge value, standard deviation and entropy for mammograms. The adjusting factor is presented to adjust the contrast enhancement in the whole image. Then the uniformity based-on algorithm is applied to enhance mammograms. Four quantitative measures of contrast enhancement are put forward. And for the first time, the presented algorithm is compared with two other existing contrast enhancement techniques—histogram equalization and morphological enhancement. Results: The index shows that the presented algorithm is found to perform better than histogram equalization and morphological enhancement. Conclusion: A lot of experiments and comparisons are needed to study the relativity among DSM, TBCs, TBCe and the final index. Based on those, contrast enhancement algorithm for mammograms and rational evaluation system and measures can be found.
Edge Detection on Hexagonal Structure
Authors: He Xiangjian , Wu Qiang , Jia Wenjing , Hintz Tom
Published: September 2008

Gradient-based edge detection is a straightforward method to identify the edge points in the original grey-level image. It is intuitive that in the human vision system the edge points always appear where the grey-level value is greatly changed. Spiral Architecture is a relatively new image data structure that is inspired from anatomical considerations of the primate's vision. In Spiral Architecture, each image is represented as a collection of hexagonal pixels. Edge detection on Spiral Architecture has features of fast computation and accurate localization. In this paper, we present and compare gradient-based edge detection algorithms on Spiral Architecture. The experimental results show that the edge detection on Spiral Architecture outperforms that on traditional square image structure.
Texture Feature Analysis of Coke Slice Image
Authors: Peizhen Wang , Qinfang Wang , Shangyi Gao
Published: September 2008

The micro optical texture structure is one of the most relevant characteristics of coke. In this paper, the texture features, especially the fractal feature, of coke slice image is analysed, and a box-counting algorithm is implemented to calculate the fractal dimension of coke slice image. At the same time, some co-occurrence matrix-based statistical texture features are also analysed. From the experimental results, the relationships between fractal dimension statistical texture parameters and the porosity of coke are developed, which provide an important basis for the auto analysis of coke quality.
The Image Retrieval and Relevance Feedback Methods Based on Region
Authors: Wei-Hua Cen , Shao-Zhen Ye
Published: September 2008

Traditional image retrieval method based on global features can only extract low-level features, which are far from the semantics that human expects. So there is a huge gap between low-level features and high-level semantics. In order to overcome this gap, two approaches have been widely used: high-level semantic image representation and relevance feedback. The paper is based on region representation that comes closely to the semantics. Region-based image retrieval (RBIR) can effectively exclude the affection of backgrounds. The main work in the paper is summarized as follows: Firstly in order to solve the problems of image segment and similarity measure, an algorithm about detecting visual attended region with respect to image segment is proposed in the paper. This algorithm combined human visual attention model can effective detect the meaningful regions. And the paper proposes a similarity measure algorithm named Modified Integrated Region Matching (MIRM), which is more robust for over segmented images. Secondly this paper focuses on the applications of relevance feedback in RBIR. By studying three cases that may occur in relevance feedback respectively, this paper introduces some relevance feedback algorithms. Those are image coding and cluster based relevance feedback algorithm, Mapping Convergence (MC) based relevance feedback algorithm, Adaptive Boosting (AdaBoost) Support Vector Machines (SVM) based relevance feedback algorithm, Asymmetric Bagging SVM based relevance feedback algorithm and region representation based SVM relevance feedback algorithm. A large number of experimental results demonstrate that all the algorithms, both region based image representation and relevance feedback, proposed in this paper can improve the performance and efficiency of image retrieval.
A New Colorization Algorithm Based on Dynamic Neighbor-Relevant Chromatic Channel Information
Authors: Chen Zhaojiong , Ye Dongyi , Zhao Xin
Published: September 2008

This paper is concerned with the problem of automatic colorization of grayscale images via color transfer. Some deficiencies of Welsh's colorization algorithm are pointed out and analyzed. Then, a new colorization algorithm is proposed, which uses a new similarity function and a new search strategy for pixel matching. The new function incorporates both the luminance information and chromatic values of previously colorized neighboring pixels. The intrinsic space clustering property of an image is taken into account in the strategy by using Hilbert filling curve scanning order. Experimental results showed that the proposed algorithm outperforms Welsh's algorithm in both colorization effect and computational complexity. Moreover, the proposed similarity function and search strategy can easily be embedded into other colorization algorithms to improve their performance.
An Improved Morphology Connective Criterion Based on Complete Lattice for Lane Detection
Authors: Cai Hui , Cai Jinhui , Zhang Guangxin , Zhou Zekui
Published: September 2008

In order to make lane detection robust to noise in complex circumstance, a novel mathematical morphology connective criterion based on Complete Lattice was proposed. Firstly, histogram of connective element was calculated based on Jump-connective criterion. Secondly, the valley of the image histogram of connective element was computed as a minimal threshold. Only above the threshold, the smooth-connective criterion was used for binary segmentation. Finally, binary morphological erosion and dilation operator were employed to solve background disturb problem. It was demonstrated by series of experiments that the proposed approach is effective in suppressing noise, and the recognition rate is about 99.0∼99.6% even when the road appearance is disturbed by shadows, stain and varying illumination.
A Blind Watermarking Algorithm for Digital Image Based on DMWT and CBWT
Authors: Yulong Shu Zhibiaoand Lian
Published: September 2008

A novel blind digital image watermarking scheme is proposed in this paper. It makes full use of the multi-resolution of discrete multiple wavelet transform (DMWT) to embed a binary image watermark into the original image by changing energy difference of cross binding wavelet tree (CBWT). Experimental results indicate that the watermark embedded with the proposed algorithm is invisible, robust and secure.
A Color Image Denoising and Enhancement Model Based on CB Color Model
Authors: Na-Ping Chen , You-Dong Zeng
Published: September 2008

In this paper, we propose a new functional model for denoising and enhancing the chromaticity component of color images. This model separates the color data into chromaticity and brightness. The three color channels of each pixel are regarded as a 3-dimensional vector, and the unit directional vector and its magnitude represent the chromaticity and the pixel brightness separately. The brightness component is processed by an improved forth-order PDE model which was proposed by authors in [8]. For the chromaticity component, it is considered as an embedded surface on Riemannian manifold. A physical quantity in the form of vector product and the unit norm restriction on chromaticity component are introduced into the energy functional of the proposed model. Furthermore, we give a detailed derivation of Euler-Lagrange equation for the energy functional. Numerical experimental results show that the model can preserve the chromatic characteristics while removing Gaussian noise and salt-pepper noise.
A Multiscale Method for Modeling Transport in Porous Media on Unstructured Corner-Point Grids
Authors: Aarnes Jørg E. , Efendiev Yalchin
Published: September 2008

Multiscale solution methods are currently under active investigation for the simulation of subsurface flow in heterogeneous formations. These procedures capture the effects of fine-scale permeability variations through the calculation of specialized coarse-scale basis functions. Most of the multiscale techniques presented to date address subgrid capturing in pressure solution (elliptic/parabolic equations). In this paper we propose a multiscale method for solving transport equations on a coarse grid. In this method the global flow is computed on a coarse grid scale, but information from a fine scale velocity field is used to improve accuracy. The method is applied to incompressible and immiscible two-phase flow on a synthetic geological model with corner-point grid geometry. Although corner-point grids are given on a logically Cartesian format, the resulting grids are unstructured in physical space. The numerical results demonstrate that the multiscale method gives nearly the same flow characteristics as simulations where the transport equation is solved on the scale of an underlying fine grid.
Global Scale-up on Reservoir Models with Piecewise Constant Permeability Field
Authors: Wu Xiao-Hui , Parashkevov Rossen R. , Stone Matthew T. , Lyons Stephen L.
Published: September 2008

Global scale-up was first proposed in the 1980s, and its benefits are well-described in the literature. However, global scale-up has not been widely applied in practice due to significant technical challenges. In this paper, we analyze some of the theoretical and numerical difficulties and present practical resolutions. First, we derive the flux and energy formulations for scale-up by using a Multiscale Finite Element framework. These formulations can be applied to local, extended local and global scale-up. Then we present a new method to improve scale-up accuracy for geo-cellular models with piecewise constant permeability. On these models, large jumps in the permeability field lead to well-known singularities in the flow solutions, making them difficult to be calculated accurately. We show that inaccurate flow solutions can lead to large scale-up errors. To mitigate the effect of the singularities and improve the scale-up accuracy, we have developed a hybrid method for solving flows which utilizes the fact that the Continuous Galerkin (CG) finite elment method and the Mixed finite element method provide upper and lower bounds, respectively, for the effective permeability. The new method uses CG to compute the pressure solution followed by a weighted L2 projection of the numerical fluxes to enforce local mass conservation. Numerical examples are presented to demonstrate the effectiveness of the hybrid method.
Adaptive Damage Simulation of Concrete Using Heterogeneous Multiscale Models
Authors: Eckardt S. , Könke C.
Published: September 2008

In this paper, an adaptive heterogeneous multiscale model, which couples substructures with different length scales into one numerical model, is introduced for the simulation of damage in concrete. In the presented approach, the evolution of microcracks is simulated using a mesoscale model, which explicitly represents the heterogeneous material structure of concrete, namely aggregates, mortar matrix and interfacial transition zone. The mesoscale model is restricted to the damaged parts of the structure, whereas undamaged regions are simulated on the macroscale. As a result, an adaptive enlargement of the mesoscale model during the simulation is necessary.
The Dynamic Priority Based Scheduling Algorithm for Hard Real-Time Heterogeneous Cmp Application
Authors: Wang Man , Du Zhihui , Liu Zhiqiang , Hao Song
Published: September 2008

Heterogeneous Chip Multiprocessors is a hotspot in CMP. In order to boost its potential power, the two-level scheduling architecture and the relevant DPK (Dynamic priority and 0–1Knapsack) algorithm is proposed in this paper to handle the scheduling problem for multiple DAG-structure hard real-time applications. Based on the characters of CMP, three dispatch queues in application level and task level are provided in the architecture to consider the multiple DAG-structure applications as a whole. In the application level, the DPK algorithm utilizes Laxity, a dynamic parameter to measure the current urgency of each application rather than the static deadline discussed in most other literatures. In the task level, the algorithm not only considers the sub-jobs of the application with the highest priority, but also at the end of each scheduling step, finds other proper unscheduled sub-jobs in any application to fill the idle time slice generated in this scheduling step just like the classical 0–1 Knapsack problem. According to the algorithm analysis and simulation experiments, with the DPK algorithm, the Successful Rate can be increased and the idle time of each processor is reduced.
Multiscale Edge Extraction Using the Fuzzy Rules
Authors: Lu Ruihua , Yang Ming
Published: September 2008

This paper proposes multiscale edge extraction using the fuzzy rules. Its cardinal idea is that edges can be gained usually via extracting large-amplitude parts of signal changes in neighboring pixels. However, it is very difficult to get a threshold for distinguishing the large signal differences from small ones, because image characteristics are ambiguous and the threshold should be varied according to some local characteristics of the image. The proposed technique can perform a proper control of the threshold for separating the small-scale output relying on the value of the large-scale output. Here, the fuzzy rules are used to consider the unstableness and uncertainty of the signals. Multiscale edge extracting can obtain multiscale edges which contain more detail information in comparison with monoscale edges. Besides, edge tracing can be performed to obtain more precise edges by dividing the amplitude of the output into three components with two thresholds and making a decision with the fuzzy rules. Computer simulations verify the effective performance of the proposed edge extracting technique.
On Homotopy Perturbation and Variational Iteration Methods for Linear and Nonlinear Heat Transfer Equations
Authors: Ganji D.D. , Rezania A. R. , Ghorbali A. R.
Published: September 2008

The traditional perturbation methods depend on a small parameter which is difficult to be found for real-life nonlinear and linear problems. To overcome this shortcoming, two new powerful analytical methods are introduced to solve heat transfer problems in this work. One is He's variational iteration method (VIM) and the other is He's homotopy-perturbation method (HPM). VIM is to construct correction functionals using general Lagrange multipliers identified optimally via the variational theory, and the initial approximations can be freely chosen with unknown constants. HPM deforms a difficult problem into a simple problem which can be easily solved. In this work, we use HPM and VIM to solve linear and nonlinear parabolic equation with variable parameters, which are functions on time and space. This type of equation governs on numerous scientific and engineering problems.
Study on Near-Optimal Path Finding Strategies in a Road Network
Authors: Jun Shi , Jian-Yuan Li , Han Cao , Xi-Li Wang
Published: September 2008

In this paper we analyze the existing defects of hierarchical and nonhierarchical path finding algorithm respectively in detail and present a hierarchical path finding algorithm based on the heuristic directing search approach which is used for promoting the nodes of lower level to higher level in the road network. The improved heuristic-hierarchical path finding algorithm was tested on road network of Xi'an city with a two-level hierarchy. The experimental results show that the heuristic based hierarchical path finding algorithm has been found to be over 25 times faster than the Dijkstra's algorithm and the ratio of the highest level road obtained by heuristic based hierarchical path finding algorithm is twice as much as the Dijkstra's algorithm. This means that the hierarchical path finding algorithm is suitable for the status of long-distance between origin and destination ( O- D). We also propose a novel yet simple path finding strategy based on a threshold, that is, if the distance of O- D is less than the threshold which was obtained by means of statistical analysis the nonhierarchical path finding algorithm will be used, otherwise we use hierarchical path finding algorithm to find a near-optimal or satisfactory path in city road network. The testing results of Xi'an city road network show that the roads which were found out using this new path finding strategy are easy to be adopted by drivers.
Diseconomies of Managing in Acquisitions: Evidence from Civil Lawsuits
Authors: Shaver J. Myles , Mezias John M.
Published: September 2008

The difficulties of managing and coordinating operations as firms expand are expected to increase disproportionately with firm size. If firms face such diseconomies of managing, then acquisitions should make the combined entity more difficult to manage than the two entities operating independently. To document the existence of diseconomies of managing in acquisitions, we examine the change in civil lawsuit judgments involving acquired firms pre- and postacquisition. Civil lawsuit judgments can capture breakdowns in management oversight that cause firms to take actions that a prudent firm would not take or fail to take actions that a prudent firm would take. We find that acquired entities face a significant increase in lawsuit judgments postacquisition. We describe why our findings provide evidence of diseconomies of managing and highlight why managerial diseconomies should be an important consideration when managing or examining acquisition strategies.
Biochemical and molecular investigation of two Korean patients with glycogen storage disease type III
Authors: Oh Sue-Hyun , Park Hyung-Doo , Ki Chang-Seok , Choe Yon-Ho , Lee Soo-Youn
Published: September 2008

: Glycogen storage disease type III (GSD-III) is an inborn error of glycogen metabolism caused by a deficiency of the glycogen debranching enzyme, amylo-1,6-glucosidase,4-α-glucanotransferase (AGL). Here, we describe two unrelated Korean patients with GSD-III and review their clinical and laboratory findings.

: The patients were 18- and 11-month-old girls. They presented with hepatosplenomegaly, developmental delay and hypotonia. The routine laboratory findings showed an elevated serum aspartate aminotransferase, alanine aminotransferase, creatine kinase and triglyceride levels. The blood lactate and uric acid levels were within normal limits. PCR and direct sequencing were performed to determine genetic findings.

: Glycogen quantitation was markedly increased and AGL activity was undetectable in both patients. Sequence analysis of the

: GSD-III should be ruled out when a patient presents with hepatic abnormalities, hypoglycemia, myopathy and hyperlipidemia. This is the first report of confirmation of GSD-III in Korean patients by biochemical and genetic findings.

Clin Chem Lab Med 2008;46:1245–9.
Impedance spectroscopy and circuit modeling of Southern pine above 20% moisture content
Authors: Zelinka Samuel L. , Rammer Douglas R. , Stone Donald S.
Published: September 2008

Impedance spectra were collected from Southern pine (Pinus spp.) equilibrated to a moisture content 20% and a saturated condition. Cylindrical graphite electrodes were embedded in the wood so that they met nearly end-to-end along a line parallel to the grain, and impedance properties were characterized as functions of electrode spacing and electrode contact pressure at frequencies between 1×10-1 and 3×105 Hz. The data exhibit a low-frequency tail that can be fit with a Warburg element, indicative of a diffusive motion of charge carriers. Values of the Warburg impedance were compared with previously published data on molar conductivities of endogenous mineral ions in wood. The data suggest that mineral ions are the predominant charge carriers in wood at low frequencies and high moisture contents based on the strong correlation between the Warburg impedance and molar conductivities.
A comparative study of bamboo Lyocell fiber and other regenerated cellulose fibers 2nd ICC 2007, Tokyo, Japan, October 25–29, 2007
Authors: Yang Gesheng , Zhang Yaopeng , Shao Huili , Hu Xuechao
Published: September 2008

A new type of regenerated cellulose fiber can be made from bamboo cellulose by the Lyocell process. In this paper, the morphology and crystal structure of the bamboo Lyocell fiber was investigated by optical microscopy, scanning electron microscopy, and wide angle X-ray diffractometry. Moreover, the mechanical properties, fibrillation behavior, moisture adsorption property, negative ion effect, and antibacterial capability of the bamboo Lyocell fiber were studied. The results showed that the bamboo Lyocell fiber proved to be similar to the structure and properties of wood Lyocell fiber, such as smooth surface, circular cross-section, high crystallinity, high tensile strength, low elongation at break, good moisture adsorption property, and easy fibrillation. Furthermore, the bamboo Lyocell fiber surpassed wood Lyocell fiber concerning negative ion effect and antibacterial property.
Cell wall features with regard to mechanical performance. A review COST Action E35 2004–2008: Wood machining – micromechanics and fracture
Authors: Salmén Lennart , Burgert Ingo
Published: September 2008

The mechanical performance of wood and wood products is highly dependent on the structural arrangement and properties of the polymers within the fibre cell wall. To improve utilisation and manufacture of wood materials, there is an increasing need for a more detailed knowledge regarding structure/property relations at the micro- or nanostructural level. In this article, recent developments regarding our understanding of the wood cell wall structure and its mechanical performance are summarised. The new results are interpreted in relation to property performances of wood fibres and wood tissues. Suggestions are made for future requirements for research in this field.
Fracture behaviour of wood and its composites. A review COST Action E35 2004–2008: Wood machining – micromechanics and fracture
Authors: Stanzl-Tschegg Stefanie E. , Navi Parviz
Published: September 2008

Fracturing of wood and its composites is a process influenced by many parameters, on the one hand coming from the structure and properties of wood itself, and on the other from influences from outside, such as loading mode, velocity of deformation, moisture, temperature, etc. Both types of parameters may be investigated experimentally at different levels of magnification, which allows a better understanding of the mechanisms of fracturing. Fracture mechanical methods serve to quantify the fracture process of wood and wood composites with different deformation and fracturing features. Since wood machining is mainly dominated by the fracture properties of wood, knowledge of the different relevant mechanisms is essential. Parameters that influence the fracture process, such as wood density, orientation, loading mode, strain rate and moisture are discussed in the light of results obtained during recent years. Based on this, refined modelling of the different processes becomes possible.
Convergence rates and source conditions for Tikhonov regularization with sparsity constraints
Authors: Lorenz D. A.
Published: September 2008

This paper addresses the regularization by sparsity constraints by means of weighted ℓ
p
penalties for 0 ≤ p ≤ 2. For 1 ≤ p ≤ 2 special attention is payed to convergence rates in norm and to source conditions. As main results it is proven that one gets a convergence rate of in the 2-norm for 1 < p ≤ 2 and in the 1-norm for p = 1 as soon as the unknown solution is sparse. The case p = 1 needs a special technique where not only Bregman distances but also a so-called Bregman-Taylor distance has to be employed.

For p < 1 only preliminary results are shown. These results indicate that, different from p ≥ 1, the regularizing properties depend on the interplay of the operator and the basis of sparsity. A counterexample for p = 0 shows that regularization need not to happen.
Mechanical influences on bone development in children
Authors: Schoenau E , Fricke O
Published: September 2008

This review focuses on methodological concepts in the evaluation of skeletal muscle function and on adaptation. It is now thought that the critical property of bone is strength rather than weight, and that control of bone strength is mainly exercised through the effect of the mechanical loads brought to bear on bone. Muscle contraction places the greatest physiological load on bone, and so the stability of bone must be adapted to muscle strength (the functional muscle–bone unit). The described suggestions and recommendations outline a new concept: bone mass and strength should not be related to age. There is now more and more evidence that bone mass and strength should be related to muscle function. Thus analyzed, there is no such entity as ‘peak bone mass’. Many studies are presently under way to evaluate whether these novel approaches increase the sensitivity and specificity of fracture prediction in an individual. Furthermore, the focus of many bone researchers is shifting away from bone mass to bone geometry or bone strength and their relationship with the driving muscle system.
Plasma pigment epithelium-derived factor is positively associated with obesity in Caucasian subjects, in particular with the visceral fat depot
Authors: Wang Ping , Smit Egbert , Brouwers Martijn C G J , Goossens Gijs H , van der Kallen Carla J H , van Greevenbroek Marleen M J , Mariman Edwin C M
Published: September 2008

Objective

Adipose tissue releases factors (adipokines) that influence local, peripheral as well as central processes. In the present study, we determined the relationship between plasma concentration of a recently identified adipokine, pigment epithelium-derived factor (SERPINF1), and human obesity, particularly specific adipose tissue depots, and other features of the metabolic syndrome.

Methods

We examined the plasma concentration of SERPINF1, anthropometric parameters, abdominal s.c. and visceral adipose tissue, lipid, glucose, insulin, and alanine aminotransferase level in a non-diabetic general Caucasian population (n=59).

Results

Plasma SERPINF1 level in males (6.2±2.1 μg/ml) was higher than in females (3.1±1.4 μg/ml; P<0.001). Plasma SERPINF1 was positively correlated with age and all features of metabolic syndrome. However, in multiple linear regression analysis with adjustment for age and gender, only visceral fat thickness (β=0.361, P=0.010) and body mass index (β=0.288, P=0.008) were significant independent determinants of plasma SERPINF1 level, together with gender (β=−0.424, P<0.001).

Conclusions

We conclude that the plasma SERPINF1 level is strongly associated with body adiposity, in particular with the visceral fat depot in the non-diabetic general population. This association may (partly) explain the relationship between SERPINF1 and metabolic syndrome in this population.
Aryl hydrocarbon receptor-interacting protein and pituitary adenomas: a population-based study on subjects exposed to dioxin after the Seveso, Italy, accident
Authors: Pesatori Angela Cecilia , Baccarelli Andrea , Consonni Dario , Lania Andrea , Beck-Peccoz Paolo , Bertazzi Pier Alberto , Spada Anna
Published: September 2008

Objective

The pathogenesis of sporadic pituitary tumors is unknown. Loss-of-function mutations of aryl hydrocarbon receptor-interacting protein (AIP) have been identified in patients with familial pituitary tumors. AIP is a chaperone protein with multifunction properties, including modulation of the transcriptional activity of the aryl hydrocarbon receptor, which mediates toxicological and carcinogenic dioxin effects.

Design

We investigated the incidence of pituitary tumors in the Seveso population exposed to 2,3,7,8-tetrachlorodibenzo-para-dioxin following an industrial accident in 1976.

Methods

Through the hospital discharge registration system of Lombardy Region, we identified incident cases of pituitary adenomas between 1976 and 1996 in the Seveso population, subdivided in zone A (n=804), B (n=5.941), and R (n=38.624) according to high, intermediate, and low exposure to dioxin respectively, and in the surrounding non-contaminated area, as reference (n=232 745).

Results

We identified 42 pituitary adenomas in the reference area, 1 prolactinoma in zone A (rate ratio (RR) 6.2; 95% CI 0.9–45.5, P=0.07), 2 nonfuctioning pituitary tumors (NFPAs) in zone B (RR 1.9; 95% CI 0.5–7.7, P=0.39), and 3 prolactinomas and 2 NFPAs in zone R (RR 0.7; 95% CI 0.3–1.8, P=0.48).

Conclusions

The study is unique with regard to the availability of epidemiological and clinical data in an area of relatively pure dioxin exposure. The study indicates no statistically significant increase of incident pituitary tumors in this area, although the tendency toward a higher risk (three cases in zones A and B) of pituitary tumors in subjects exposed to high–intermediate dioxin concentrations in comparison with nonexposed population suggests the need for extended follow-up.
Serum pituitary antibodies in normal pregnancy and in patients with postpartum thyroiditis: a nested case–control study
Authors: Manetti Luca , Parkes Arthur B , Lupi Isabella , Di Cianni Graziano , Bogazzi Fausto , Albertini Sonia , Morselli Lisa Linda , Raffaelli Valentina , Russo Dania , Rossi Giuseppe , Gasperi Maurizio , Lazarus John H , Martino Enio
Published: September 2008

Objectives

The aim of this study was to evaluate antipituitary antibody (APA) prevalence in a series of patients with postpartum thyroiditis (PPT) during pregnancy and in the postpartum.

Design

We conducted a nested case–control study on consecutive PPT and normal pregnant women at the Centre for Endocrine and Diabetes Sciences in Cardiff and at the Department of Endocrinology in Pisa.

Methods

We enrolled 30 women with PPT: 17 were hypothyroid (Hypo), 7 with hyperthyroidism (Hyper) and 6 with a transient hyperthyroidism followed by hypothyroidism (Biphasic). Twenty-one healthy pregnant women served as controls. APA (measured using indirect immunofluorescence), free thyroxine, free triiodothyronine, TSH, antithyroid autoantibodies, and thyroid ultrasound were performed during pregnancy and postpartum. The stored sera have been sent to Pisa, where serum APA, IGF1, and cortisol were measured.

Results

APA were found in 8 out of the 30 PPT patients (26.7%) and in one normal pregnancy (4.7%, P=0.063). Three out of the seventeen Hypo with PPT (17.6%), three out of the seven Hyper PPT (42.8%), and two out of the six Biphasic PPT (33.3%) were positive for APA. APA prevalence was not significantly different in the PPT subgroups (P=0.453). With one exception, APA all increased in the postpartum period (87.5%, P<0.016). Basal serum IGF1 and cortisol were in the normal range with the exception of two patients with positive APA who presented low serum IGF1 levels (36 and 45 ng/ml).

Conclusions

APA are frequently present in the postpartum period in patients affected by PPT. Further studies are necessary to evaluate whether APA in PPT patients are associated with pituitary function impairment.
Oxytetracycline Treatment Reduces Bacterial Diversity of Intestinal Microbiota of Atlantic Salmon
Authors: Navarrete Paola , Mardones Pamela , Opazo Rafael , Espejo Romilio , Romero Jaime
Published: September 2008

The effect of oxytetracycline (OTC) treatment on intestinal bacterial populations in juvenile Atlantic salmon Salmo salar was evaluated. Oxytetracycline was administered by way of medicated feed to fish held in experimental tanks. Restriction fragment length polymorphism and sequencing of 16S rDNA from isolates were used to analyze the intestinal microbiota before, during, and after OTC administration. The microbiota from untreated fish was more diverse, consisting mainly of Pseudomonas, Acinetobacter, Bacillus, Flavobacterium, Psycrobacter, and Brevundimonas spp. In contrast, the microbiota of the OTC-treated group was characterized by lower diversity and consisted only of Aeromonas, clustering with A. sobria and A. salmonicida. Antibiotic-resistant isolates were identified as Aeromonas spp.; sequencing the resistance determinant showed it to be the tetE gene. Overall, OTC treatment changed the composition of the intestinal microbiota of Atlantic salmon, as evidenced by a reduction in bacterial diversity. These results support the current concern that antibiotic treatment can facilitate the proliferation of opportunistic bacteria by eradicating competing microorganisms.
Optimum Densities of Three Leguminous Cover Crops for Suppression of Smooth Pigweed (Amaranthus hybridus)
Authors: Collins Amanda S. , Chase Carlene A. , Stall William M. , Hutchinson Chad M.
Published: September 2008

Additive experiments were performed to determine optimum densities for nematode-suppressive cover crops to extend the benefit from the cover crops by also using them for weed suppression. In a preliminary experiment in 2002, a range of cover-crop densities was evaluated in mixtures with smooth pigweed at 5 plants m−2. Smooth pigweed biomass accumulation was suppressed by cowpea, sunn hemp, and velvetbean at the lowest cover-crop populations (38, 44, and 15 plants m−2, respectively). Based on these results, experiments were conducted in 2003 at two locations to examine the effects of lower cover-crop densities on a higher smooth pigweed population density of 15 plants m−2. Cowpea and velvetbean densities ranged from 10 to 50 plants m−2and sunn hemp from 20 to 100 plants m−2. In 2003, cowpea density had no effect on smooth pigweed biomass. However, smooth pigweed biomass declined linearly by 51% as sunn hemp density increased to 100 plants m−2. Similarly, as velvetbean densities increased, smooth pigweed biomass decreased showing a linear response at one location and quadratic response at the second location. Maximum suppression of smooth pigweed biomass by velvetbean occurred at the highest cover-crop density (50 plants m−2). Excellent suppression of smooth pigweed at 5 plants m−2or fewer will result in densities of 38, 44, and 15 plants m−2of cowpea, sunn hemp, and velvetbean. However, with smooth pigweed at 15 plants m−2, optimum cover-crop densities were not obtained because no suppression was obtained with cowpea, and the lowest weed biomass with sunn hemp and velvetbean occurred with the highest densities used. Therefore, when high smooth pigweed densities are expected, sunn hemp and velvetbean should be used at densities greater than 100 and 50 plants m−2, respectively, and further study with higher densities will be needed to define optima.
Glyphosate Hinders Purple Nutsedge (Cyperus rotundus) and Yellow Nutsedge (Cyperus esculentus) Tuber Production
Authors: Webster Theodore M. , Grey Timothy L. , Davis Jerry W. , Culpepper A Stanley
Published: September 2008

The phase-out of methyl bromide requires alternative nutsedge management options in vegetable systems. Options that target tuber production, the primary means of reproduction, will be most beneficial. A study was conducted to evaluate the response of purple nutsedge and yellow nutsedge foliar growth and tuber production to a range of glyphosate rates. Glyphosate was applied at six rates between 0.41 and 2.57 kg ae ha−1to 5-wk-old nutsedge plants with multiple shoots. The rate of glyphosate needed to reduce growth 50% (I50) was similar for purple nutsedge foliar growth (0.58 kg ha−1) and tuber biomass (0.55 kg ha−1). In contrast,I50for yellow nutsedge foliar growth was 0.73 kg ha−1, which was greater than theI50for tuber biomass (0.41 kg ha−1). First-order tubers, those directly attached to the initial tuber, had anI50of 0.70 and 0.44 kg ha−1of glyphosate for purple nutsedge and yellow nutsedge tuber biomass, respectively. For all higher-order tubers,I50values ranged from 0.29 to 0.60 and 0.14 to 0.30 kg ha−1of glyphosate for purple nutsedge and yellow nutsedge tuber biomass, respectively. Glyphosate at 0.74 kg ha−1prevented fourth-order purple nutsedge and third-order yellow nutsedge tuber production (terminal tubers for yellow nutsedge). Fifth- and sixth-order purple nutsedge tuber production was eliminated by the lowest tested rate of glyphosate (0.41 kg ha−1). Effective nutsedge management options will require consistent control between spring and autumn crops. Glyphosate is economical, poses no herbicide carryover issues to vegetables, and minimizes nutsedge tuber production; therefore, it is a suitable candidate to manage nutsedges.
Acclimation of Palmer Amaranth (Amaranthus palmeri) to Shading
Authors: Jha Prashant , Norsworthy Jason K. , Riley Melissa B. , Bielenberg Douglas G. , Bridges William
Published: September 2008

Experiments were conducted to investigate the acclimation of Palmer amaranth to shading. Plants were grown in the field beneath black shade cloths providing 47 and 87% shade and in full sunlight (no shading). All photosynthetic measurements were taken 4 wk after initiating the shade treatments. Photosynthetic rates of Palmer amaranth grown under 47% shade increased with increasing photosynthetic active radiation (PAR) similar to 0% shade-grown plants. Light-saturated photosynthetic rates were predicted beyond the highest measured PAR of 1,200 µmol m−2s−1for plants grown under 0 and 47% shade. Plants acclimated to increased shading by decreasing light-saturated photosynthetic rates from 60.5 µmol m−2s−1under full sun conditions to 26.4 µmol m−2s−1under 87% shade. Plants grown under 87% shade lowered their light compensation point. Rate of increase in plant height was similar among shade treatments. Plants responded to increased shading by a 13 to 44% reduction in leaf appearance rate (leaf number growing degree days [GDD]−1) and a 22 to 63% reduction in main-stem branch appearance rate (main-stem branch number GDD−1) compared with full sunlight. Palmer amaranth specific leaf area increased from 68 to 97 cm2g−1as shading increased to 87%. Plants acclimated to 47% shade by increasing total leaf chlorophyll from 22.8 µg cm−2in full sunlight to 31.7 µg cm−2when shaded; however, the increase was not significant at 87% shading. Thus, it is concluded that Palmer amaranth shows photosynthetic and morphological acclimation to 87% or less shading.
Germination Ecology of Southern Crabgrass (Digitaria ciliaris) and India Crabgrass (Digitaria longiflora): Two Important Weeds of Rice in Tropics
Authors: Chauhan Bhagirath S. , Johnson David E.
Published: September 2008

Southern and India crabgrass are important grass weeds of rice in many tropical countries. Environmental factors influenced seed germination and seedling emergence of these weeds. Seeds of both species germinated at a range of alternating temperatures (25/15, 30/20, and 35/25 C day/night), though the germination of southern crabgrass was reduced at the lowest alternating temperatures (25/15 C). Light stimulated germination of both species; however, a small proportion of southern crabgrass seeds germinated in the dark. Germination of India crabgrass was influenced to a greater degree by increasing salt and water stresses than was southern crabgrass. Seeds of both species germinated over a wide range of pH between 5 and 10. Seedling emergence of both species (98% for southern crabgrass and 94% for India crabgrass) was greatest for seeds placed on the soil surface. Seed burial depth of 2 cm completely inhibited emergence of India crabgrass, whereas for southern crabgrass, this depth was 8 cm. Knowledge gained from this study is expected to contribute to developing components of integrated weed management strategies for these species.
Nitrogen Fertilizer Rate Effects on Weed Competitiveness is Species Dependent
Authors: Blackshaw Robert E. , Brandt Randall N.
Published: September 2008

Information on nitrogen fertilizer effects on crop–weed competitive interactions might aid in developing improved weed management programs. A controlled environment study was conducted to examine the effect of three N rates on the competitive ability of four weed species grown with wheat. The four weed species were chosen to represent species that varied in their growth responsiveness to nitrogen (N): Persian darnel (low), Russian thistle (low), redroot pigweed (high), and wild oat (high). Wheat and each weed species were grown in a replacement series design at N rates of 60, 120, and 240 mg N kg−1soil. The competitive ability of the low N-responsive species, Persian darnel and Russian thistle, was not influenced by N rate, supporting our hypothesis that N rate would have little effect on the competitiveness of species responding minimally to N. Conversely, the competitiveness of the high N-responsive species redroot pigweed progressively improved as N rate increased. However, wild oat competitiveness was unaffected by N fertilizer rate. There is some evidence from this study to suggest that fertilizer management strategies that favor crops over weeds deserve greater attention when weed infestations consist of species known to be highly responsive to higher soil N levels. Information gained in this study will be used to advise farmers of the importance of strategic fertilizer management in terms of both weed management and crop yield.