bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Stage Sugarcane Selection Using Different Plot Sizes
Authors: Milligan Scott B. , Balzarini Monica , Gravois Kenneth A. , Bischoff Keith P.
Published: September 2007

Most sugarcane (Saccharum spp.) cultivar development programs use single‐row plots in their first clonal trials. We hypothesized that a larger plot size would increase the accuracy of selection and compared selection efficiencies of 1.82‐, 3.35‐, and 4.88‐m single‐row plots. The 1.82‐m plots generated larger genetic and residual variances than the larger plot sizes for sugar and cane yields and stalk number and weight but not for sugar concentration. Broad‐sense heritabilities for yield components for the examined plot sizes differed little. Genetic correlations for the same trait among the plot sizes were high for most traits except stalk number. Consequently, the correlated response in larger plots to selection for the same trait selected in small plots was not affected by plot size. The proportion needed to confidently retain the top 1% of the genotypes was also not affected by plot size but was very high (>80%) for sugar and cane yields. It was substantially lower for sugar concentration and stalk weight (<43%), whereas it was higher (43–55%) for stalk number. The estimated probability of retaining the top genotypes by selecting the top 33% of the population was 59 to 66% for sugar and cane yields, but it ranged from 77 to 90% for the other yield components. Thus, increasing the plot size would not improve the selection efficiency of the program, but the study highlighted that there was still room for improvement in the initial stage of selection.
AFLP and SCAR Markers Linked to Tomato Spotted Wilt Virus Resistance in Tobacco
Authors: Moon H. , Nicholson J. S.
Published: September 2007

Tomato spotted wilt virus (TSWV) is a serious disease in tobacco (Nicotiana tabacum L.). The breeding line ‘Polalta’ contains a single dominant gene conferring resistance to TSWV that was introgressed from N. alata Link & Otto. The resistance is tightly associated with an abnormal plant type, however, and traditional backcrossing has been ineffective in producing normal plants with TSWV resistance. A potential strategy to overcome this problem is to use molecular markers to select against alien chromatin in backcross progeny. Amplified fragment length polymorphism (AFLP) technology and bulked segregant analysis were applied to identify markers linked to the resistance gene. The DNA bulks from susceptible and resistant doubled haploid lines derived from a cross between susceptible cultivar K326 and Polalta were analyzed to identify linked markers. An F2 population and the doubled haploids were used to construct a 2.5‐cM map of this locus containing 17 coupling phase and seven repulsion phase markers. By selecting for resistant plants with an improved plant type and marker profile in a BC3 population, four plants were identified that were missing 1 to 14 of the AFLP markers associated with the alien chromatin, demonstrating that rare recombination events can be identified. Four AFLP fragments were successfully converted to sequence characterized amplified region markers suitable for large‐scale screening. This approach may facilitate development of TSWV‐resistant tobacco cultivars.
A Modified Colorimetric Method for Phytic Acid Analysis in Soybean
Authors: Gao Y. , Shang C. , Maroof M. A. Saghai , Biyashev R. M. , Grabau E. A. , Kwanyuen P. , Burton J. W. , Buss G. R.
Published: September 2007

A quantitative, reproducible, and efficient phytic acid assay procedure is needed to screen breeding populations and support genetic studies in soybeans [Glycine max (L.) Merr.]. The objective of this study was to modify the colorimetric Wade reagent method and compare the accuracy and applicability of this new method in determining seed phytic acid content in soybean with three well‐established phytic acid assay methods: anion exchange column (AEC), high‐performance liquid chromatography (HPLC), and 31P nuclear magnetic resonance (NMR). The CV for repeated measurements of a low phytic acid soybean mutant, CX1834‐1‐6, ranged from 1.8 to 4.2% (n = 5), indicating the results were precise and reproducible. Phytic acid content of 42 soybean genotypes as determined by this method showed a correlation of 93.7 to 96.6% with the measurements by AEC, HPLC, and NMR. According to analysis of covariance, using inorganic P content as a predictor, phytic acid P content in a given sample analyzed by the four assay methods can be estimated with four linear regression models at the α = 0.01 level. Compared with HPLC, AEC, and 31P NMR, this modified colorimetric method is simpler and less expensive for assaying a large number of samples, allowing its effective application in breeding and genetic studies of low phytic acid soybean.
Multidisciplinary Teams: A Necessity for Research in Precision Agriculture Systems
Authors: Bullock David S. , Kitchen Newell , Bullock Donald G.
Published: September 2007

Precision agriculture may offer great promise for the future, but extensive research is required if that promise is to be realized. The research will not be easy, for few, if any, individuals have sufficiently broad training in the many disciplines (e.g., economics, engineering, crop and soil sciences, pest management) required to design the experiments, interpret the data, and ultimately provide answers for the practical, economically oriented farm management questions being asked. We are convinced that many experiments would benefit, as ours did, from collaborative research conducted by multidisciplinary teams. From our effort, we learned much about the nature of precision agriculture, but we also learned about the nature of research and the value of expertise outside of our own areas. In the case of the former, we learned that precision agriculture is highly dependent on, and perhaps even defined by, engineering technology, but the profitable use of the technology depends on a thorough understanding of the physical and biological factors of the field and crop. It appears that much of the technology is only profitable when a producer possess very detailed field characteristic information. Unfortunately, the level of information required may be impossible to obtain for many of the proposed uses of precision agriculture technology. In the latter case, we gained an appreciation of the skills and expertise of those from other disciplines. We believe that multidisciplinary teams are a necessity for this work, and we recommend that the existing research community recognize this need and provide rewards for participation in interdisciplinary research.
Thrombospondin-1 Is an Endogenous Activator of TGF-β in Experimental Diabetic Nephropathy In Vivo
Authors: Daniel Christoph , Schaub Kathrin , Amann Kerstin , Lawler Jack , Hugo Christian
Published: September 2007

OBJECTIVE—Transforming growth factor-β (TGF-β), the central cytokine responsible for the development of diabetic nephropathy, is usually secreted as a latent procytokine complex that has to be activated before it can bind to its receptors. Recent studies by our group demonstrated that thrombospondin-1 (TSP-1) is the major activator of latent TGF-β in experimental glomerulonephritis in the rat, but its role in diabetic nephropathy in vivo is unknown.

RESEARCH DESIGN AND METHODS—Type 1 diabetes was induced in wild-type (n = 27) and TSP-1–deficient mice (n = 36) via streptozotocin injection, and diabetic nephropathy was investigated after 7, 9.5, and 20 weeks. Renal histology, TGF-β activation, matrix accumulation, and inflammation were assessed by immunohistology. Expression of fibronectin and TGF-β was evaluated using real-time PCR. Furthermore, functional parameters were examined.

RESULTS—In TSP-1–deficient compared with wild-type mice, the amount of active TGF-β within glomeruli was significantly lower, as indicated by staining with specific antibodies against active TGF-β or the TGF-β signaling molecule phospho-smad2/3 or the typical TGF-β target gene product plasminogen activator inhibitor-1. In contrast, the amount of glomerular total TGF-β remained unchanged. The development of diabetic nephropathy was attenuated in TSP-1–deficient mice as demonstrated by a significant reduction of glomerulosclerosis, glomerular matrix accumulation, podocyte injury, renal infiltration with inflammatory cells, and renal functional parameters.

CONCLUSIONS—We conclude that TSP-1 is an important activator of TGF-β in diabetic nephropathy in vivo. TSP-1–blocking therapies may be considered a promising future treatment option for diabetic nephropathy.
Physical mechanisms and methods employed in drug delivery to tumors
Authors: Bešić Erim
Published: September 2007

Physical mechanisms and methods employed in drug delivery to tumors

In addition to several well-known drug delivery strategies developed to facilitate effective chemotherapy with anticancer agents, some new approaches have been recently established, based on specific effects arising from the applications of ultrasound, magnetic and electric fields on drug delivery systems. This paper gives an overview of newly developed methods of drug delivery to tumors and of the related anticancer therapies based on the combined use of different physical methods and specific drug carriers. The conventional strategies and new approaches have been put into perspective to revisit the existing and to propose new directions to overcome the threatening problem of cancer diseases.
Development of spray-dried co-precipitate of amorphous celecoxib containing storage and compression stabilizers
Authors: Dhumal Ravindra , Shimpi Shamkant , Paradkar Anant
Published: September 2007

Development of spray-dried co-precipitate of amorphous celecoxib containing storage and compression stabilizers

The purpose of this study was to obtain an amorphous system with minimum unit operations that will prevent recrystallization of amorphous drugs since preparation, during processing (compression) and further storage. Amorphous celecoxib, solid dispersion (SD) of celecoxib with polyvinyl pyrrollidone (PVP) and co-precipitate with PVP and carrageenan (CAR) in different ratios were prepared by the spray drying technique and compressed into tablets. Saturation solubility and dissolution studies were performed to differentiate performance after processing. Differential scanning calorimetry and X-ray powder difraction revealed the amorphous form of celecoxib, whereas infrared spectroscopy revealed hydrogen bonding between celecoxib and PVP. The dissolution profile of the solid dispersion and co-precipitate improved compared to celecoxib and amorphous celecoxib. Amorphous celecoxib was not stable on storage whereas the solid dispersion and co-precipitate powders were stable for 3 months. Tablets of the solid dispersion of celecoxib with PVP and physical mixture with PVP and carrageenan showed better resistance to recrystallization than amorphous celecoxib during compression but recrystallized on storage. However, tablets of co-precipitate with PVP and carageenan showed no evidence of crystallinity during stability studies with comparable dissolution profiles. This extraordinary stability of spray-dried co-precipitate tablets may be attributed to the cushioning action provided by the viscoelastic polymer CAR and hydrogen bonding interaction between celecoxib and PVP. The present study demonstrates the synergistic effect of combining two types of stabilizers, PVP and CAR, on the stability of amorphous drug during compression and storage as compared to their effect when used alone.
Synthesis and brain antihypoxic activity of some aliphatic and arylaliphatic amides of caffeine-8-thioglycolic acid
Authors: Mitkov Javor , Danchev Nikolai , Nikolova Irina , Zlatkov Alexander
Published: September 2007

Synthesis and brain antihypoxic activity of some aliphatic and arylaliphatic amides of caffeine-8-thioglycolic acid

The synthesis of some aliphatic and arylaliphatic amides of caffeine-8-thioglycolic acid was studied. The structures of synthesized compounds were proved by micro-analyses, IR- and1H NMR data. Values of acutep.o.andi.p.toxicity in mice show lower toxicity compared to caffeine. Declines in spontaneous locomotor activity support the idea of depressive CNS activity of the compounds. Two compounds exhibited brain antihypoxic activity (5aand5bagainst haemic and circulatory hypoxia, respectively).
Evaluating Research Studies That Address Prognosis for Patients Receiving Physical Therapy Care: A Clinical Update
Authors: Beattie Paul F , Nelson Roger M
Published: September 2007

A prognosis is a broad statement that predicts a patient's likely status, or degree of change, at some time in the future. Clinicians are likely to improve the accuracy of their judgments of prognosis by incorporating relevant research findings. In recent years, there has been substantial growth in the number of primary studies and systematic reviews addressing prognosis for people likely to receive physical therapy care. The purpose of this clinical update is to provide a framework for identifying, appraising, and utilizing these research findings to help make prognostic judgments.
Scaling of Dynamics in the Earliest Stages of Walking
Authors: Holt Kenneth G , Saltzman Elliot , Ho Chia-Ling , Ulrich Beverly D
Published: September 2007

Background and Purpose

Although the description of mature walking is fairly well established, less is known about what is being learned in the process. Such knowledge is critical to the physical therapist who wants to teach children with developmental delays. The purpose of this experiment was to test the notion that learning to walk efficiently involves fine-tuning the body’s controllable stiffness (by co-contraction and isometric muscle contractions against gravity) to match (at a 1:1 scaling) the gravitational (pendular) stiffness of the swing leg.

Subjects

The study participants were 7 children with typical development and the newly emerged ability to walk 6 steps without falling (ages 11 months to 1 year 5 months at the onset of walking).

Methods

Pendular stiffness and spring stiffness were estimated from the equations of motion for a hybrid model with kinematic data as children walked over ground. Testing occurred once per month for the first 7 months of walking.

Results

After the first month of walking, children walked with greater spring stiffness than would be predicted by the model. The ratio began to approach the predicted value (1:1) as the months progressed.

Discussion and Conclusion

The results of this and a previous study of the pendular dynamics of gait suggest that learning to walk is a 2-stage process. The first stage involves the child’s discovery of how to conserve energy by inputting a particular muscular force at the correct moment in the cycle. The second stage involves the fine-tuning of the soft-tissue stiffness that takes advantage of the resonance characteristics of tissues. In order to address developmental delays, investigators must discover the dynamic resources used for the activity and attempt to foster their development. A number of interventions that probe this approach are discussed.
Successful detection of verbal and visual concealed knowledge using an RT‐based paradigm
Authors: Seymour Travis L. , Kerlin Jess R.
Published: September 2007

An increasing number of researchers are exploring variations of the Concealed Knowledge Test (CKT) as alternatives to traditional ‘lie‐detector’ tests. For example, the response times (RT)‐based CKT has been previously shown to accurately detect participants who possess privileged knowledge. Although several studies have reported successful RT‐based tests, they have focused on verbal stimuli despite the prevalence of photographic evidence in forensic investigations. Related studies comparing pictures and phrases have yielded inconsistent results. The present work compared an RT‐CKT using verbal phrases as stimuli to one using pictures of faces. This led to equally accurate and efficient tests using either stimulus type. Results also suggest that previous inconsistent findings may be attributable to study procedures that led to better memory for verbal than visual items. When memory for verbal phrases and pictures were equated, we found nearly identical detection accuracies. Copyright © 2007 John Wiley & Sons, Ltd.
Integrated process and product analysis: A multiscale approach to paint spray
Authors: Li Jia , Xiao Jie , Huang Yinlun , Lou Helen H.
Published: September 2007

It is known that even if process information at macroscale is fully accessible and properly utilized in manufacturing, product and process performance may be still not sufficiently assured. This may be due to the influence of phenomena at finer scales, which are normally not measurable and thus unknown in operation. Besides, even if such information is available, how to integrate it across scales is yet to be discovered. In this work, an integrated process and product analysis methodology is developed via a multiscale approach. This methodology can provide deep understanding of various interrelationships across multiple scales of length and time, which could be essential for substantial improvement of product and process performance. The methodology is successfully applied to the analysis of the paint spray operation in automotive surface coating, with the extension of the analysis from the macroscale of 10−2–101 m and 100–102 s to the meso‐macroscale of 10−6–101 m and 10−5–102 s. Model‐based simulation reveals various new opportunities for simultaneous improvement of coating quality, energy and material efficiencies, and environmental cleanness. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Transendothelial migration of leukocytes is promoted by plasma from a subgroup of immune thrombocytopenic purpura patients with small‐vessel ischemic brain disease
Authors: Jimenez Joaquin J. , Jy Wenche , Mauro Lucia M. , Horstman Lawrence L. , Fontana Vincenzo , Ahn Yeon S.
Published: September 2007

We previously described a subgroup of immune thrombocytopenic purpura (ITP) patients presenting with recurring transient ischemic attack‐like symptoms and progressive cognitive impairment due to small vessel disease (SVD) seen in the brain. They presented minimal bleeding despite thrombocytopenia, and platelet activation was elevated compared to classic ITP. On the hypothesis that the blood–brain barrier (BBB) is compromised in this subgroup, we investigated the effect of plasma from SVD‐ITP patients on the transendothelial migration of leukocytes (TEML). Brain microvascular endothelial cells (BMVEC) were grown to confluence on 6.5‐μm pore filters and plasma from 10 healthy controls, 20 classic ITP, and 5 SVD‐ITP were added and incubated 24 hr. Then 1 × 105 monocytes (U937) were added and the number migrated through the EC monolayer after 6 hr was measured by flow cytometry. The effect on TEML of danazol was also assessed. We found that plasma from SVD‐ITP but not classic ITP induced 10‐fold rise in EC activation marker CD62E and a sevenfold increase in TEML, to 38.5% ± 12.5% of cells migrated, compared to normal controls (5.6% ± 1.2%) or classic ITP (6.1% ± 0.2%), P < 0.001. Preincubation of U937 with endothelial microparticles (EMP) increased TEML by 20.0% ± 6.4% with SVD‐ITP plasma, significantly more than with classic ITP or control plasmas, P = 0.003. Pretreatment of cultures with danazol (100 μg/mL) inhibited TEML by 25% in all wells tested, whether or not EMP were added. In summary, SVD‐ITP plasma activates EC and augments TEML, suggesting plasma‐mediated BBB dysfunction in this syndrome. Danazol modestly but significantly inhibited TEML. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
Forest fragmentation, the decline of an endangered primate, and changes in host–parasite interactions relative to an unfragmented forest
Authors: Gillespie Thomas R. , Chapman Colin A.
Published: September 2007

Forest fragmentation may alter host–parasite interactions in ways that contribute to host population declines. We tested this prediction by examining parasite infections and the abundance of infective helminths in 20 forest fragments and in unfragmented forest in Kibale National Park, Uganda. Over 4 years, the endangered red colobus (Procolobus rufomitratus) declined by 20% in fragments, whereas the black‐and‐white colobus (Colobus guereza) in fragments and populations of both colobines in unfragmented forest remained relatively stable. Seven nematodes (Strongyloides fulleborni, Strongyloides stercoralis, Oesophagostomum sp., an unidentified strongyle, Trichuris sp., Ascaris sp., and Colobenterobius sp.), one cestode (Bertiella sp.), and three protozoans (Entamoeba coli, Entamoeba histolytica/dispar, and Giardia sp.) were detected. Infection prevalence and the magnitude of multiple infections were greater for red colobus in fragmented than in unfragmented forest, but these parameters did not differ between forests for black‐and‐white colobus. Infective‐stage colobus parasites occurred at higher densities in fragmented compared with unfragmented forest, demonstrating greater infection risk for fragmented populations. There was little evidence that the nature of the infection was related to the size of the fragment, the density of the host, or the nature of the infection in the other colobine, despite the fact that many of the parasites are considered generalists. This study suggests that forest fragmentation can alter host–parasite dynamics and demonstrates that such changes can correspond with changes in host population size in forest fragments. Am. J. Primatol. 70:222–230, 2008. © 2007 Wiley‐Liss, Inc.
Downregulation of macrophage inhibitory molecules in multiple sclerosis lesions
Authors: Koning Nathalie , Bö Lars , Hoek Robert M. , Huitinga Inge
Published: September 2007

Objective

Inflammatory and demyelinating activity of activated resident macrophages (microglia) and recruited blood‐borne macrophages are considered crucial in multiple sclerosis (MS) lesion development. The membrane glycoproteins CD200 and CD47, highly expressed on neurons, are mediators of macrophage inhibition via their receptors CD200R and signal‐regulatory protein α, respectively, on myeloid cells. We determined the expression pattern of immune inhibitory molecules in relation to genes involved in macrophage activation and MS lesion pathology.

Methods

Laser dissection microscopy was combined with real‐time polymerase chain reaction to quantitatively study these gene expression patterns in specific subareas (rim, center, and normal‐appearing white matter) of chronic active and inactive MS lesions.

Results

Hallmarks of MS pathology were confirmed by messenger RNA expression patterns of glial fibrillary acidic protein, neurofilament (NF), myelin basic protein, growth factors, chemokines and receptors, and macrophage activation markers, although expression of osteopontin and αB‐crystallin was decreased. CD200 and CD47 were downregulated in the center of chronic active and inactive MS lesions. CD47 expression was also decreased in the rim of chronic active lesions, where complement expression was increased. This expression profile was also found in normal‐appearing white matter surrounding these lesions, but not surrounding inactive lesions. Expression of CD200R and signal‐regulatory protein α was not altered.

Interpretation

These data suggest that diminished immune inhibition via decreased CD200 and CD47 expression contributes to a disturbed equilibrium in macrophage and microglia activation in MS lesions. Furthermore, this may result in a proinflammatory predisposition in the area surrounding chronic active lesions, thereby contributing to axonal injury, demyelination, and possible lesion expansion. Ann Neurol 2007
The effect of Gamma and EB irradiation on the mechanical properties of thermosetting polymers and their composites
Authors: Ikeo Yasuhiro , Chihara Yasutaka , Aoki Kazuhiko , Hirayama Akira , Matsuda Satoshi , Kishi Hajime , Murakami Atsushi
Published: September 2007

The degradation mechanism in molecular order by electron beam (EB) irradiation for three types of thermosetting polymers (bisphenol type vinylester, Novolak‐type vinylester and tetra functional epoxy resin) is confirmed by dynamic mechanical thermal analysis (DMTA) and the swelling test in this study. The level of degradation in molecular order is quite high. The same result was observed in Novolak‐type vinylester but not in tetrafunctional epoxy resin. The results of the swelling test showed that the cross‐linking networks were destroyed by γ‐ or electron beam irradiation remarkably for both the vinylester resins. For the tetrafunctional epoxy resin, γ‐ or electron irradiation does not give any effect even in molecular order in high radiation intensity such as 20 MGy. However, the mechanical properties such as bending strength, modulus and fracture toughness of all composites (both vinylester resin and tetrafunctional epoxy resin composites) reinforced by a chopped‐strand glass mat or flake‐like mica change a little after 20 MGy EB irradiation. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
Polymer–organoclay hybrids by polymerization into montmorillonite‐vinyl monomer interlayers
Authors: Rehab Ahmed , Akelah Ahmed , Agag Tarek , Betiha Mohamed
Published: September 2007

A different series of polymer–clay hybrid materials have been prepared by modification of the clay with different vinyl monomers, followed by polymerization of different ratios of vinyl monomers–clay with the monomers, such as methyl methacrylate, hydroxyethyl methacrylate, and styrene‐maleic anhydride. The materials were investigated by IR, which confirmed the intercalation of vinyl‐cation within the clay interlayers, and by TGA, which illustrated that phosphonium cation has high thermal stability than ammonium cation. Swelling studies of these materials in different organic solvents showed that the swelling degree increases as clay ratio decrease, and also showed higher swelling relative to vinyl–clay. X‐ray diffraction illustrated that the nanocomposites were exfoliated up to a 25 wt % content of organoclay relative to the amount of polymer. SEM and TEM examined the micrograph, which showed a good dispersion of the polymers into clay galleries, and formation of nanosize particles ranged 150–300 Å. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Thermo gravimetric analysis and morphological behavior of castor oil based polyurethane–polyester nonwoven fabric composites
Authors: Kumar Maddur Nagaraju Satheesh , Siddaramaiah
Published: September 2007

Castor oil (CO) based polyurethane (PU)– polyester nonwoven fabric composites were fabricated by impregnating the polyester nonwoven fabric in a reactive composition containing CO and diisocyanate. Composites were fabricated with two different isocyanates such as toluene‐2, 4‐diisocyanate (TDI) and hexamethylene diisocyanate (HMDI). Thermogravimetric analysis (TGA) studies of the composites were performed to establish the thermal stability and their mode of thermal degradation. It was found that degradation of neat PU takes place in two steps and that of polyester nonwoven fabric reinforced PU composites takes place in three steps. From the TGA thermograms, a little improvement in thermal stability incase of polyester nonwoven fabric reinforced PU composites were noticed compared to unreinforced PUs. Degradation kinetic parameters were obtained for the composites using Broido, Coats and Redfern, and Horowitz and Metzger methods. Tensile fractured composite specimens were used to analyze the morphology of the composites by scanning electron microscopic technique. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Amphoteric hydrogels for immobilization of enzymes using template polymerization technique
Authors: El‐Masry Mansour M. , Elnashar Magdy M. M. , El‐Sherif Hazem M.
Published: September 2007

Novel ionizable amphoteric hydrogels were prepared from poly(acrylic acid) and dimethylaminoethyl methacrylate monomer, employing template polymerization technique. The mode of interaction, as proved by FTIR, was multiple H‐bonding between the tertiary amino group of the monomer and the carboxylic groups of the polymer. The impact of varying equal polymer–monomer feed ratios from 0.1 to 1.1 on the swelling dynamics was examined. Penetrant sorption experiments demonstrated that the swelling behavior depends strongly on the polymer complex composition. The polymer complex of feed ratio 0.5 : 0.5 (polymer : monomer) showed maximum swelling percentage. The mechanism of the polymer complexes swelling was probably a non‐Fickian with n values approaching Fickian behavior. The hydrogels showed maximum swelling efficiencies of 27 folds and 13.5 folds in drastic acidic and basic medium, respectively, using polymer complex of 0.5 : 0.5 feed ratio. Because of reversibility and rapidity of swelling, the gel could be considered as a mechanochemical system. The prepared hydrogel successfully immobilized the industrially used β‐galactosidase as an acidic model enzyme. The novel immobilized enzyme showed a remarkable improvement in its activity (13.8 μmol min−1 mg−1) compared to the free enzyme (3.2 μmol min−1 mg−1). The optimum pH values for free and immobilized enzyme were 4.5–5 and 4, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Evidence for interchange reconnection between a coronal hole and an adjacent emerging flux region
Authors: Baker D. , van Driel‐Gesztelyi L. , Attrill G.D.R.
Published: September 2007

Coronal holes are regions of dominantly monopolar magnetic field on the Sun where the field is considered to be ‘open’ towards interplanetary space. Magnetic bipoles emerging in proximity to a coronal hole boundary naturally interact with this surrounding open magnetic field. In the case of oppositely aligned polarities between the active region and the coronal hole, we expect interchange reconnection to take place, driven by the coronal expansion of the emerging bipole as well as occasional eruptive events. Using SOHO/EIT and SOHO/MDI data, we present observational evidence of such interchange reconnection by studying AR 10869 which emerged close to a coronal hole. We find closed loops forming between the active region and the coronal hole leading to the retreat of the hole. At the same time, on the far side of the active region, we see dimming of the corona which we interpret as a signature of field line ‘opening’ there, as a consequence of a topological displacement of the ‘open’ field lines of the coronal hole. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Trans‐Planckian signatures in the cosmic microwave background?
Authors: Lorenz L.C.
Published: September 2007

With the increasingly precise measurement of the cosmic microwave background (CMB), cosmology has entered an era where a model's predictions become testable to percent‐level accuracy. In particular, the CMB spectrum has so far provided impressive support for the scenario of inflation, first invented to solve outstanding problems of standard cosmology. While current data (COBE, WMAP etc.) have already constrained cosmological parameters like Ω0 to high precision, next generation instruments such as the PLANCK satellite should give access to specific characteristics of the inflationary mechanism itself. Another tantalizing idea has been discussed in this context: Given the enormous expansion of the Universe during the phase of inflation, could it be that even Planck scale physics has been stretched to observable distances and is therefore within grasp in the CMB observations? In this contribution, I discuss the possibility of carrying through the calculation of the perturbation spectrum from an ansatz for short distance physics right to its imprint in the CMB. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magneto‐seismology of the solar atmosphere
Authors: Verth G.
Published: September 2007

Magnetohydrodynamic (MHD) waves in solar coronal loops, which were previously only predicted by theory have actually been detected with space‐borne instruments. These observations have given an important and novel tool to measure fundamental parameters in the magnetically embedded solar corona. This paper will illustrate how information about the magnetic and density structure along coronal loops can be determined by measuring the frequency or amplitude profiles of standing fast kink mode oscillations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Imaging the cool stars in the interacting binaries AE Aqr, BV Cen and V426 Oph
Authors: Watson C.A. , Steeghs D. , Dhillon V.S. , Shahbaz T.
Published: September 2007

It is well known that magnetic activity in late‐type stars increases with increasing rotation rate. Using inversion techniques akin to medical imaging, the rotationally broadened profiles from such stars can be used to reconstruct ‘Doppler images’ of the distribution of cool, dark starspots on their stellar surfaces. Interacting binaries, however, contain some of the most rapidly rotating late‐type stars known and thus provide important tests of stellar dynamo models. Furthermore, magnetic activity is thought to play a key role in their evolution, behaviour and accretion dynamics. Despite this, we know comparatively little about the magnetic activity and its influence on such binaries. In this review we summarise the concepts behind indirect imaging of these systems, and present movies of the starspot distributions on the cool stars in some interacting binaries. We conclude with a look at the future opportunities that such studies may provide. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of the effect of metallicity on the amplitudes of Cepheids
Authors: Klagyivik P. , Szabados L.
Published: September 2007

Results concerning the dependence of photometric and radial velocity amplitudes on metallicity are presented based on about 200 Galactic classical Cepheids pulsating in the fundamental mode. The Galactic distribution of the [Fe/H] value of Cepheids is also studied. We show that the photometric amplitude ratio AI/AV is independent of metallicity. The observed dependence of this ratio on the pulsation period does not correspond to the theoretical predictions. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical investigation of the orbit of Interball‐1
Authors: Nagy I. , Érdi B.
Published: September 2007

We investigated the motion of the Earth's artificial satellite Interball‐1 by using a method suitable for the computation of large eccentricity orbits. Though the measured and the computed orbital elements differ from each other within the measured error bound, we found a slight tendency for secular decreasing in the semi‐major axis, caused probably by electromagnetic drag. We analysed the dominant role of the Moon in the variations of the orbital eccentricity, leading to zero perigee height and the end of the lifetime of the satellite. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Calcineurin/NFAT signaling in the β‐cell: From diabetes to new therapeutics
Authors: Heit Jeremy J.
Published: September 2007

Pancreatic β‐cells in the islet of Langerhans produce the hormone insulin, which maintains blood glucose homeostasis. Perturbations in β‐cell function may lead to impairment of insulin production and secretion and the onset of diabetes mellitus. Several essential β‐cell factors have been identified that are required for normal β‐cell function, including six genes that when mutated give rise to inherited forms of diabetes known as Maturity Onset Diabetes of the Young (MODY). However, the intracellular signaling pathways that control expression of MODY and other factors continue to be revealed. Post‐transplant diabetes mellitus in patients taking the calcineurin inhibitors tacrolimus (FK506) or cyclosporin A indicates that calcineurin and its substrate the Nuclear Factor of Activated T‐cells (NFAT) may be required for β‐cell function. Here recent advances in our understanding of calcineurin and NFAT signaling in the β‐cell are reviewed. Novel therapeutic approaches for the treatment of diabetes are also discussed. BioEssays 29:1011–1021, 2007. © 2007 Wiley Periodicals, Inc.
Maternal cyclin B levels “Chk” the onset of DNA replication checkpoint control in Drosophila
Authors: Yellajoshyula Dhananjay , Patterson Ethan S. , Kroll Kristen L.
Published: September 2007

In many animals, early development of the embryo is characterized by synchronous, biphasic cell divisions. These cell divisions are controlled by maternally inherited proteins and RNAs. A critical question in developmental biology is how the embryo transitions to a later pattern of asynchronous cell divisions and transfers the prior maternal control of development to the zygotic genome. The most‐common model regarding how this transition from maternal to zygotic control is regulated posits that this is a consequence of the limitation of maternal gene products, due to their titration during early cell divisions. Here we discuss a recent article by Crest et al.1 that instead proposes that the balance of Cyclin‐dependent Kinase 1 and Cyclin B (Cdk1‐CycB) activity relative to that of the Drosophila checkpoint kinase Chk1 determines when asynchronous divisions begin. BioEssays 29:949–952, 2007. © 2007 Wiley Periodicals, Inc.
Computational studies of CXCR1, the receptor of IL‐8/CXCL8, using molecular dynamics and electrostatics
Authors: Huynh Nicholas , Mallik Buddhadeb , Zhang Li , Martins‐Green Manuela , Morikis Dimitrios
Published: September 2007

The three‐dimensional structure of IL‐8/CXCL8 has been previously determined using NMR spectroscopy and X‐ray crystallography, but the structure of the receptors for this chemokine has not been determined experimentally. We present here the development of a model for the structure of the IL‐8/CXCL8 receptor CXCR1, using a combination of homology modeling and a molecular dynamics simulation. Based on this model, we discuss the analysis of structural, dynamic, and physicochemical properties of CXCR1. We focused on the role of pairwise ionic interactions in local structural stability of CXCR1 and the role of electrostatic potentials in recognition of CXCR1 with IL‐8/CXCL8. We have performed theoretical mutations of six charged amino acids in CXCR1, which abolish binding as suggested by earlier experimental data, to shed light on the effect of charge on association ability. We propose that the observed loss of binding in the six CXCR1 mutants is owed to loss of local structural stability, rather than hindrance of the recognition process because of changes in the overall electrostatic properties of the receptor. Based on further structural analysis, we propose some mutations of charged residues involving ion pairs in different elements of transmembrane helices and extracellular loops, which are expected to alter the local structure and possibly affect binding. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 52–61, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Modelling the long-term cost-effectiveness of endovascular or open repair for abdominal aortic aneurysm
Authors: Epstein D M , Sculpher M J , Manca A , Michaels J , Thompson S G , Brown L C , Powell J T , Buxton M J , Greenhalgh R M
Published: September 2007

Background

Recent randomized trials have shown that endovascular abdominal aortic aneurysm repair (EVAR) has a 3 per cent aneurysm-related survival benefit in patients fit for open surgery, but it also has uncertain long-term outcomes and higher costs. This study assessed the cost-effectiveness of EVAR.

Methods

A decision model was constructed to estimate the lifetime costs and quality-adjusted life years (QALYs) with EVAR and open repair in men aged 74 years. The model includes the risks of death from aneurysm, other cardiovascular and non-cardiovascular causes, secondary reinterventions and non-fatal cardiovascular events. Data were taken largely from the EVAR trial 1 and supplemented from other sources.

Results

Under the base-case (primary) assumptions, EVAR cost £3800 (95 per cent confidence interval (c.i.) £2400 to £5200) more per patient than open repair but produced fewer lifetime QALYs (mean − 0·020 (95 per cent c.i. − 0·189 to 0·165)). These results were sensitive to alternative model assumptions.

Conclusion

EVAR is unlikely to be cost-effective on the basis of existing devices, costs and evidence, but there remains considerable uncertainty.
Role of CYP2C9 and CYP2C19 polymorphisms in patients with atherosclerosis
Authors: Ercan B. , Ayaz L. , Çiçek D. , Tamer L.
Published: September 2007

The arachidonic acid metabolizing CYP enzymes with prominent roles in vascular regulation are epoxygenases of the two gene family which generate epoxyeicosatrienoic acids. Carriers of CYP2C9 mutant alleles exhibit a diminished CYP2C9 metabolic capacity leading to decreased endothelium‐derived hyperpolarizing factors (EDHF) synthesis and an increased risk for atherosclerosis. We investigated whether the polymorphisms of CYP2C9/19 are related with atherosclerosis. We examined 108 patients having angioraphically ≥70 coronary artery narrowing and 90 healthy controls. CYPC2C9/19*2 and CYP2C9/19*3 alleles were investigated in both patients and controls by a real time PCR instrument. There was no significant difference in the distribution of the CYP2C9*2/*3 alleles between cases and the controls. We found that smoker patients having CYP2C9*2 heterozygote genotype have 3.7‐fold risk of developing atherosclerosis. CYP2C19*3 heterozygote alleles are more frequent in patients than in controls (10.2%, 5.6% respectively) and it is related with a three‐fold risk of atherosclerosis (odds ratio (OR) = 3.75, confidence interval (CI) = 0.75–18.65). It becomes clear that cigarette smoking can cause almost all major diseases prevalent today, such as cancer or heart disease. This inter‐subject variability in cigarette‐induced pathologies is partly mediated by genetic variants of genes that may participate in detoxification processes, e.g., cytochrome P450 (CYP), cellular susceptibility to toxins, such as p53, or disease development such as atherosclerosis. Copyright © 2007 John Wiley & Sons, Ltd.
Increasing pH Causes Faster Anion‐ and Cation‐Transport Rates through a Synthetic Ion Channel
Authors: Madhavan Nandita , Gin Mary S.
Published: September 2007

Ion‐channel mimics are able to transmit electrical signals across phospholipid membranes, and can be envisioned as nanoswitches for molecular electronics. Here, we reported the use of pH to alter ion‐transport rates through a synthetic aminocyclodextrin ion channel. Both cation‐ and anion‐transport rates were found to increase with an increase in pH due to the unique electrostatics of the multiple ammonium groups that line the channel pore. Such pH regulation of ion transport rates is unique and can be exploited for sensing applications.
Investigating the Structural and Functional Consequences of Circular Permutation on Lipase B from Candida Antarctica
Authors: Qian Zhen , Fields Christina J. , Lutz Stefan
Published: September 2007

The engineering of lipase B from Candida antarctica (CALB) by circular permutation has yielded over sixty hydrolase variants, and several show significantly improved catalytic performance. Here we report a detailed characterization of ten selected enzyme variants by kinetic and spectroscopic methods to further elucidate the impact of circular permutation on the structure and function of CALB. Our experiments identify lipase variants with up to 175‐fold enhanced kcat/KM values over wild‐type. In addition, circular permutation does not change the enzymes’ enantiopreference and preserves or even improves their enantioselectivity compared to that of the wild‐type enzyme. Finally, our spectroscopic analyses suggest that the structural effects of circular permutation on CALB are mostly local, concentrating on regions near the native and new protein termini. The observed changes in secondary structure and protein thermostability vary among enzyme variants but directly correlate with the locations of the new termini, a first step towards a predictive framework.
A comparison of different pre‐treatment procedures for reducing heteroscedasticity and other irrelevant features in data prior to modelling of benthic count profiles
Authors: Flåten Geir Rune , Grung Bjørn , Kvalheim Olav M.
Published: September 2007

Challenges related to quantifying environmental disturbance biologically from benthic count profiles by using the Community Disturbance Index (CDI) approach are assessed. A pre‐treatment framework incorporating removal of irrelevant features, scaling and converting transformations is proposed. Within this framework the characteristics of benthic count data are discussed and possible consequences for the CDI calculations are shown. It is established that the benthic count data need to be corrected for heteroscedasticity while scaling is found to be unnecessary for the CDI calculations. Copyright © 2007 John Wiley & Sons, Ltd.
A [3]Rotaxane of the Amide Type
Authors: Vögtle Fritz , Dünnwald Thomas , Händel Mirko , Jäger Ralf , Meier Stephan , Harder Gabriele
Published: September 2007

Two new rotaxane types, the [2]rotaxanes 12a,b and the [3]rotaxane 13, have been synthesised by treating the “axle” 7 with the stopper component 9 in the presence of the “wheel” 8. A nonionic template intermediate of type 10 is proposed. The [3]rotaxane 13 was only obtained when the chain of the “axle” had a certain length: with n = 1 only [2]rotaxane 12 a was isolated, whereas with n = 2 the [3]rotaxane 13 was formed besides the [2]rotaxane 12 b. This suggests that more extended rotaxanes and polyrotaxanes can be synthesised by the template strategy.
Microstructured Peptide‐Functionalised Surfaces by Electrochemical Polymerisation
Authors: Heiduschka Peter , Göpel Wolfgang , Beck Werner , Kraas Wolfgang , Kienle Stefan , Jung Günther
Published: September 2007

For the first time, antigenic peptides have been immobilised by electrochemical polymerisation after having been modified with a polymerisable functional group. 3‐Hydroxyphenylacetic acid was chosen as the novel polymerisable group. The synthetic peptides represent epitopes of the bovine foot and mouth disease virus and of the sodium channel of the cardiac muscle. The polymerisation was performed by applying a constant anodic potential or by cyclic voltammetry. A combination of these two methods was also employed, that is, cyclic voltammetry with a delay at the anodic vertex potential. No additional free phenolic monomer was required for the polymerisation. The layers formed by the polymerisation were recognised by specific antibodies. The specific binding of the antibodies to the polymer film could be demonstrated by ELISA, an enzyme‐linked amperometric immunoassay, and electrochemical impedance measurements, as well as by fluorescence‐labelled antibodies. A peptide derived from laminine was also immobilised by electrochemical polymerisation. It could be shown that neuroblastoma cells adhere to this layer.