bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical explanations of variations in river meander migration rates from model comparison
Authors: Crosato Alessandra
Published: November 2009

In meandering rivers, the local channel migration rate increases with increasing bend sharpness until it reaches a maximum at a certain critical value of the bend sharpness. Beyond this critical value, the migration rate decreases if bend sharpness increases. Similarly, reach‐averaged migration rates attain a maximum at a certain river sinuosity. This work investigates the physics of these phenomena by comparing the results of two physics‐based models of different complexity, in which the migration rates are proportional to the near‐bank flow velocity excess. In the computational tests the river was allowed to meander progressively, starting from an almost straight planimetry.

Both models reproduced the observed peak in the curve describing the local migration rate as a function of the ratio radius of curvature‐channel width (R/B), with a rising limb at lower R/B values and a falling limb at higher R/B values. The rising limb can be explained by the decrease in relative lag distance between near‐bank flow velocity and forcing curvature as R/B increases. The falling limb results from the decrease in local channel curvature and near‐bank flow velocity excess. Since the models do not include flow separation, the results indicate that this phenomenon is not needed to explain the decrease of channel migration rates in sharp bends. The models reproduced also the peak in the curve describing the reach‐averaged migration rates as a function of river sinuosity The increase and then decrease of reach‐averaged migration rates as sinuosity increases appears to be mainly caused by the variation of the reach‐averaged value of the ratio R/B. Copyright © 2009 John Wiley & Sons, Ltd.
Sibship analysis of associations between SNP haplotypes and a continuous trait with application to mammographic density
Authors: Stone J. , Gurrin L. C. , Hayes V. M. , Southey M. C. , Hopper J. L. , Byrnes G. B.
Published: November 2009

Haplotype‐based association studies have been proposed as a powerful comprehensive approach to identify causal genetic variation underlying complex diseases. Data comparisons within families offer the additional advantage of dealing naturally with complex sources of noise, confounding and population stratification. Two problems encountered when investigating associations between haplotypes and a continuous trait using data from sibships are (i) the need to define within‐sibship comparisons for sibships of size greater than two and (ii) the difficulty of resolving the joint distribution of haplotype pairs within sibships in the absence of parental genotypes. We therefore propose first a method of orthogonal transformation of both outcomes and exposures that allow the decomposition of between‐ and within‐sibship regression effects when sibship size is greater than two. We conducted a simulation study, which confirmed analysis using all members of a sibship is statistically more powerful than methods based on cross‐sectional analysis or using subsets of sib‐pairs. Second, we propose a simple permutation approach to avoid errors of inference due to the within‐sibship correlation of any errors in haplotype assignment. These methods were applied to investigate the association between mammographic density (MD), a continuously distributed and heritable risk factor for breast cancer, and single nucleotide polymorphisms (SNPs) and haplotypes from the VDR gene using data from a study of 430 twins and sisters. We found evidence of association between MD and a 4‐SNP VDR haplotype. In conclusion, our proposed method retains the benefits of the between‐ and within‐pair analysis for pairs of siblings and can be implemented in standard software. Genet. Epidemiol. 34: 309–318, 2010.  © 2009 Wiley‐Liss, Inc.
Impacts of climate change on hydrological processes in the headwater catchment of the Tarim River basin, China
Authors: Liu Zhaofei , Xu Zongxue , Huang Junxiong , Charles Stephen P. , Fu Guobin
Published: November 2009

The impacts of climate change on hydrological processes in the headwater catchment of the Tarim River Basin (TRB), the largest inland river basin in China, were assessed using the variable infiltration capacity (VIC) macro‐scale hydrological model. The Delta method, a relatively simple and widely used method for constructing regional climate change scenarios for impact assessment, was used to project climate change scenarios based on GCM A2 and B2 scenarios. Projected meteorological variables for these two scenarios were inputted to the VIC model to simulate hydrological changes. The impacts of climate change on evapotranspiration and runoff in the catchment were assessed. Results showed that the runoff in winter exhibited a decreasing trend. As runoff in winter is mainly generated from snowmelt, this could have resulted from a decreasing trend in air temperature. Runoff in spring exhibited an increasing trend, which may be beneficial to agriculture. Overall, runoff in the study area showed a slight decreasing trend, while evapotranspiration exhibited an increasing trend. These results imply that water availability in the TRB is likely to become more critical in the future. Copyright © 2009 John Wiley & Sons, Ltd.
Variability in smallholders' irrigation water values: Study in North‐West Province, South Africa
Authors: Speelman S. , Frija A. , Perret S. , D'haese M. , Farolfi S. , D'haese L.
Published: November 2009

Capturing the economic value of water use is an integral part in the design of economic incentives and institutional arrangements that can ensure sustainable, efficient and equitable allocation of water. Irrigation water values of small‐scale irrigators are, however, seldom studied and too little attention is paid to the determinants of the variability of water values. In South Africa issues like the call for more efficient water allocation resulting from growing water scarcity, the approaching introduction of water charges for smallholders and the crucial role in rural development attributed to small‐scale schemes, render this knowledge even more important. This study therefore first assesses irrigation water values at small‐scale irrigation schemes in South Africa using the residual imputation method. Results reveal that, without input subsidies, smallholders have difficulties generating a profit from certain irrigated crops. This raises doubts about the capacity of smallholders to pay for water. The average economic value of irrigation water in this study is US$0.188 m−3. The water values are, however, shown to be highly variable. The General Linear Model shows that this variability can be mainly attributed to the crop choice and to the irrigation scheme design and institutional setting. Copyright © 2009 John Wiley & Sons, Ltd.
Management of microfinance institutions: Do subsidies matter?
Authors: Hudon Marek
Published: November 2009

It is estimated that donors commit between US$ 800 million and US$ 1 billion to microfinance per year. This paper analyses the management of microfinance institutions (MFIs) and its relationship with donors' subsidies. The results show that the level of subsidies granted per year is related to the management quality but not the subsidies divided by the gross loan portfolio or the total equity. Well‐managed MFIs are larger and regulated organisations but not significantly older. The organisational structure or the experience of the MFI however does not play a role in determining its financial effectiveness, except for cooperatives. Copyright © 2009 John Wiley & Sons, Ltd.
Repair of large osteochondral defects in rabbits using porous hydroxyapatite/collagen (HAp/Col) and fibroblast growth factor‐2 (FGF‐2)
Authors: Maehara Hidetsugu , Sotome Shinichi , Yoshii Toshitaka , Torigoe Ichiro , Kawasaki Yuichi , Sugata Yumi , Yuasa Masato , Hirano Masahiro , Mochizuki Naomi , Kikuchi Masanori , Shinomiya Kenichi , Okawa Atsushi
Published: November 2009

Articular cartilage has a limited capacity for self‐renewal. This article reports the development of a porous hydroxyapatite/collagen (HAp/Col) scaffold as a bone void filler and a vehicle for drug administration. The scaffold consists of HAp nanocrystals and type I atelocollagen. The purpose of this study was to investigate the efficacy of porous HAp/Col impregnated with FGF‐2 to repair large osteochondral defects in a rabbit model. Ninety‐six cylindrical osteochondral defects 5 mm in diameter and 5 mm in depth were created in the femoral trochlear groove of the right knee. Animals were assigned to one of four treatment groups: porous HAp/Col impregnated with 50 µl of FGF‐2 at a concentration of 10 or 100 µg/ml (FGF10 or FGF100 group); porous HAp/Col with 50 µl of PBS (HAp/Col group); and no implantation (defect group). The defect areas were examined grossly and histologically. Subchondral bone regeneration was quantified 3, 6, 12, and 24 weeks after surgery. Abundant bone formation was observed in the HAp/Col implanted groups as compared to the defect group. The FGF10 group displayed not only the most abundant bone regeneration but also the most satisfactory cartilage regeneration, with cartilage presenting a hyaline‐like appearance. These findings suggest that porous HAp/Col with FGF‐2 augments the cartilage repair process. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:677–686, 2010
A capital partnership: how human and venture capital affect the growth of high‐tech start‐ups
Authors: Colombo Massimo G. , Grilli Luca
Published: November 2009

Founders' human capital and venture capital (VC) are two fundamental ingredients for new venture success in high‐tech sectors. We jointly investigate their influence on the growth performance of a large sample of Italian high‐tech start‐ups and find:

the importance of both components;

some characteristics of founders' human capital also exert an indirect rather than a direct effect on growth by attracting VC;

the ‘coach’ function performed by Italian venture capitalists on invested companies is important;

a substitution rather than a complementary relationship exists between these two drivers of firm growth.

Copyright © 2009 John Wiley & Sons, Ltd.
What can venture capitalists and entrepreneurs learn from behavioral economists?
Authors: Yazdipour Rassoul
Published: November 2009

Building upon new findings from the field of behavioral finance and economics, this article provides fresh insights into how venture capitalists (VCs) and entrepreneurs perceive, experience, and deal with risk; and how they go about making decisions in their respective areas of venture creation, venture evaluation, venture growth, and investing.

By helping VCs and entrepreneurs to be cognizant of the many psychological traps that continuously get turned on at and around decision‐making times, such findings would certainly help both parties to avoid committing costly mistakes in their businesses.

Copyright © 2009 John Wiley & Sons, Ltd.
Business angels: who they really are
Authors: Ramadani Veland
Published: November 2009

Financing is a critical issue for the survival and development of small and medium‐sized enterprises. Business angels play a key role in financing these enterprises, especially innovative ones with high growth potential. Business angels fill the gap between founders, family, and friends on one side, and institutional venture capital funds on the other side, as a financing source. Business angels invest a large amount of money in seed, start‐up, and early‐stage enterprises.

Business angels are important for small and medium‐sized enterprises because they provide more than money. They are hands‐on investors and contribute their skills, expertise, knowledge, and contacts in the businesses they invest in. They are wealthy persons with great business experience, willing to invest and offer their wealth and knowledge to owners and to entrepreneurs to start or develop their businesses.

Business angels like to remain anonymous, so many ideas cannot be implemented. To address this issue, many countries establish business angel syndicates and networks to facilitate the process of matching entrepreneurs and business angels.

Copyright © 2009 John Wiley & Sons, Ltd.
Runoff, soil loss, and nutrient depletion under traditional and alternative cropping systems in the Transmexican Volcanic Belt, Central Mexico
Authors: Bravo‐Espinosa M. , Mendoza M. E. , Medina‐Orozco L. , Prat C. , García‐Oliva F. , López‐Granados E.
Published: November 2009

In the Transmexican Volcanic Belt a traditional fallow system is practiced, called “año y vez” (AV), which does not benefit soil conservation due to its low level of nutrient recycling and because soil protection is poor during the cultivation year. The objective of the present work was to measure runoff and soil and nutrient losses during three annual cycles (2002–2004) in Central Mexico under AV rotation and two alternative systems: improved traditional (IT) and traditional organic (TO). Soil losses in the three systems were moderate (<1.2 Mg ha−1 y−1) except during 2002, in which significant soil losses were recorded in IT and TO due to the scarcity of plant cover (<20 per cent) that was present throughout the rainy season. During the resting period of the AV system (2003), the annual runoff increased from 19 to about 600 per cent, compared to IT and TO without grazing. The difference in runoff was attributed to an 18 per cent increase in bulk density of soil surface (0–5 cm) caused by cattle trampling while grazing. Nutrient losses in the three treatments were mainly of N, Ca2+, Mg2+, Na+, and K+. These results suggest that AV has a higher topsoil degradation effect during the resting year than during the cultivation period. The study shows that incorporating the maize/beans‐black oat rotation and residue cover causes a low runoff response that is important in reducing soil degradation. A spatial analysis is presented of erosion at watershed level for two soil management systems assessed. Copyright © 2009 John Wiley & Sons, Ltd.
Pachymic acid inhibits cell growth and modulates arachidonic acid metabolism in nonsmall cell lung cancer A549 cells
Authors: Ling Hui , Jia Xiaobin , Zhang Yaochun , Gapter Leslie A. , Lim Yin‐shan , Agarwal Rajesh , Ng Ka‐yun
Published: November 2009

Aberrant arachidonic acid (AA) metabolism has been involved in inflammation and carcinogenesis. The key enzymes in AA metabolism such as cytosolic phospholipase A2 (cPLA2) and cyclooxygenase‐2 (COX‐2) have been implicated in the development and progression of many human cancers, including lung cancer. Hence, the blockade of these enzymes may suppress promotion and survival of human cancer cells. We and others have shown that a natural triterpenoid, pachymic acid (PA), can exhibit antiinflammatory and anticancer properties; however, its potential mechanism has not been fully clarified. In this study, we examined the effect of PA on the proliferation of human nonsmall cell lung cancer A549 cells. Furthermore, we investigated the influences of nontoxic levels of PA on AA metabolism. Additionally, the cellular events and signal transduction pathways influenced by PA were also examined. Our results showed that PA (1) inhibited anchorage‐dependent and ‐independent A549 growth in a concentration‐dependent manner, (2) induced apoptosis and disrupted mitochondrial membrane potential in A549 cells, and at nonlethal levels, (3) decreased IL‐1β‐induced activation of cPLA2 and COX‐2, (4) suppressed IL‐1β‐induced activation of mitogen‐activated protein kinases (MAPKs), and (5) inhibited IL‐1β‐stimulated nuclear factor kappa B (NF‐κB) signaling pathways. We speculate that inhibition of AA metabolism by PA is mediated in part by its inhibition of MAPKs and NF‐κB signaling pathways. Our study reveals that, apart from its cytotoxic effect, PA has the chemopreventive potential by reducing production of eicosanoids from AA metabolism. © 2009 Wiley‐Liss, Inc.
Navigator accuracy requirements for prospective motion correction
Authors: Maclaren Julian , Speck Oliver , Stucht Daniel , Schulze Peter , Hennig Jürgen , Zaitsev Maxim
Published: November 2009

Prospective motion correction in MRI is becoming increasingly popular to prevent the image artifacts that result from subject motion. Navigator information is used to update the position of the imaging volume before every spin excitation so that lines of acquired k‐space data are consistent. Errors in the navigator information, however, result in residual errors in each k‐space line. This paper presents an analysis linking noise in the tracking system to the power of the resulting image artifacts. An expression is formulated for the required navigator accuracy based on the properties of the imaged object and the desired resolution. Analytical results are compared with computer simulations and experimental data. Magn Reson Med, 2010. © 2009 Wiley‐Liss, Inc.
Improved signal to noise in proton spectroscopy of the human calf muscle at 7 T using localized B1 calibration
Authors: Versluis Maarten J. , Kan Hermien E. , van Buchem Mark A. , Webb Andrew G.
Published: November 2009

Large variations of tip angle within a slice can lead to suboptimal pulse power optimization using standard techniques, which measure the average tip angle over a slice; this effect is especially pronounced at fields of 7 T and above. A technique was introduced that performed a volume‐selective power optimization in less than 10 sec and automatically calibrates the radiofrequency pulses for subsequent spectroscopy scans. Using this technique, MR spectra were acquired in the human calf of seven healthy volunteers with a partial volume Tx/Rx coil. Increases in signal‐to‐noise ratio based upon the unsuppressed water signal between 22 ± 5% and 166 ± 42%, compared to spectra obtained with the conventional power calibration technique, were measured in different regions of the calf muscle. This new technique was able to measure the inhomogeneous radiofrequency field at 7 T and its use resulted in a considerable signal‐to‐noise ratio increase. Magn Reson Med, 2010. © 2009 Wiley‐Liss, Inc.
Multilevel ulnar neuropathy caused by multiple intraneural hemangiomas
Authors: Kim Dong Hwee , Kang Jong Woo , Park Jong Woong
Published: November 2009

Intraneural hemangioma is extremely rare, and there are no reported cases that describe multilevel ulnar neuropathy caused by multiple intraneural hemangiomas in a single nerve. We report the case of a 47‐year‐old man with multilevel ulnar neuropathy caused by multiple intraneural hemangiomas in an ipsilateral ulnar nerve. Multilevel ulnar neuropathy was detected by electrodiagnosis, and intraneural hemangiomas were suggested by ultrasonographic evaluation before the operation. Careful surgical excision under an operating microscope ameliorated the patient's symptoms without recurrence. Muscle Nerve 41: 562–566, 2010
Flame retardancy and thermal degradation of intumescent flame retardant polypropylene material
Authors: Chen Xilei , Jiao Chuanmei
Published: November 2009

The flame retardancy and thermal degradation properties of polypropylene (PP) containing intumescent flame retardant additives, i.e. melamine pyrophosphate (MPyP) and charring‐foaming agent (CFA) were characterized by limiting oxygen index (LOI), UL 94, cone calorimeter, microscale combustion calorimetry, and thermogravimetric analysis (TGA). It has been found that the PP material containing only MPyP does not show good flame retardancy even at 30% additive level. Compared with the PP/MPyP binary system, the LOI values of the PP/MPyP/CFA ternary materials at the same additive loading are all increased, and UL 94 rating is raised to V‐0 from no rating (PP/MPyP). The cone calorimeter results show that the heat release rate and mass loss rate of some ternary materials decrease in comparison with the binary material. The microscale combustion calorimetry results indicate that the sample containing 22.5 wt% MPyP and 7.5 wt% CFA has the lowest heat release rate among all samples. The TGA results show that the thermal stability of the materials increases with the addition of MPyP, while decreases with the addition of CFA. Copyright © 2009 John Wiley & Sons, Ltd.
Massively regulated genes: the example of TP53
Authors: Hollstein Monica , Hainaut Pierre
Published: November 2009

Intensive study of the TP53 gene over the last three decades has revealed a highly complex network of factors that regulate its performance. The gene has several promoters, alternative splicing occurs and there are alternative translation initiation sites. Up to 10 p53 isoforms have been identified. At the post‐translational level, p53 activity depends on its quantity in the cell and on qualitative changes in its structure, intracellular localization, DNA‐binding activity and interactions with other proteins. Both accumulation and activation are regulated by an intricate pattern of post‐translational modifications, including phosphorylation, acetylation, ubiquitination, sumoylation, neddylation, methylation and glycosylation. The Mdm2 protein, a negative regulator of p53, is the most important determinant of p53 abundance and subcellular localization. Enzymes that post‐translationally modify p53 by phosphorylation, methylation and acetylation fine‐tune p53 binding to recognition sequences in DNA and p53 interactions with transcription cofactors at promoters of target genes, thereby exerting a discriminatory role in p53 function. This multitude of parameters determining expression, modification, accumulation and localization of p53 proteins may explain how a single gene can display an extensive repertoire of activities. Presumably this is needed, because the p53 protein can have such profound consequences for a cell. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Substituent effect on local aromaticity in mono and di‐substituted heterocyclic analogs of naphthalene
Authors: Mohajeri Afshan , Shahamirian Mozhgan
Published: November 2009

A quantitative study on local aromaticity has been performed on a series of mono‐ and di‐substituted biheterocycles (quinoline, isoquinoline, quinoxaline, quinazoline). Three electronically based indices (PDI, ATI, and FLU) have been employed to investigate the substituent effect on theπ‐electron delocalization in both heterocycle and benzenoid rings. Three typical substituents (Cl, OCH3, and CN) with different inductive and resonance power have been selected. Generally, substituent causes a reduction in aromaticity irrespective of whether it is electron attracting or electron donating. It is shown that the maximum aromaticity exhibits a similar trend of Cl > CN > OCH3for all the studied rings. Moreover, it is found that the substituent situation with respect to the heteroatom has a significant influence on the aromaticity. It results from our study that in di‐substituted derivatives, irrespective of whether the two substituents form a meta or para isomer, they preferably choose the position which leads to the maximum aromaticity character. Copyright © 2009 John Wiley & Sons, Ltd.
Primary kinetic hydrogen isotope effects in deprotonations of a nitroalkane by intramolecular phenolate groups
Authors: Backstrom Nicholas , Burton Neil A. , Watt C. Ian F.
Published: November 2009

Rate constants and kinetic isotope effects have been determined for the formation of nitronate anions from the ethers 1‐(2‐methoxyphenyl)‐2‐nitropropane, 7(X = H, L = H and D) and 1‐(2‐methoxy‐5‐nitrophenyl)‐2‐nitropropane, 7(X = NO2, L = H and D), and from the corresponding phenols, 1‐(2‐hydroxyphenyl)‐2‐nitropropane, 3(X = H, L = H and D), and 1‐(2‐hydroxy‐5‐nitrophenyl)‐2‐nitropropane, 3(X = NO2, L = H and D), in aqueous basic medium. For the ethers 7, rates of deprotonation by hydroxide are comparable with those found for deprotonations of 2‐nitropropane, with kH/kD (25 °C) = 7.7 and 7.8, respectively. In both the cases, the isotope effects are conventionally temperature dependent. For the corresponding phenols 3, conditions have been established under which the deprotonations of the nitroalkane are dominated by intramolecular deprotonation by the kinetically first‐formed phenolate anion, with an estimated effective molarity EM ∼ 250. For 3 (X = H, L = H or D), kH/kD (25 °C) = 7.8, with E − E = 6.9 kJ mol−1 and AH/AD = 0.5. For 3(X = NO2, L = H or D), rates of intramolecular deprotonation are reduced 30‐fold, and an elevated kinetic isotope effect is found (kH/kD (25 °C) = 10.7). Activation parameters (E − E = 17.8 kJ mol−1 and AH/AD = 0.008) are compatible with an enhanced tunnelling contribution to reactivity in the H‐isotopomer. Copyright © 2009 John Wiley & Sons, Ltd.
The hydrodynamic and conformational properties of denatured proteins in dilute solutions
Authors: Berry Guy C.
Published: November 2009

Published data on the characterization of unfolded proteins in dilute solutions in aqueous guanidine hydrochloride are analyzed to show that the data are not fit by either the random flight or wormlike chain models for linear chains. The analysis includes data on the intrinsic viscosity, root‐mean‐square radius of gyration, from small‐angle X‐ray scattering, and hydrodynamic radius, from the translational diffusion coefficient. It is concluded that residual structure consistent with that deduced from nuclear magnetic resonance on these solutions can explain the dilute solution results in a consistent manner through the presence of ring structures, which otherwise have an essentially flexible coil conformation. The ring structures could be in a state of continual flux and rearrangement. Calculation of the radius of gyration for the random‐flight model gives a similar reduction of this measure for chains joined at their endpoints, or those containing loop with two dangling ends, each one‐fourth the total length of the chain. This relative insensitivity to the details of the ring structure is taken to support the behavior observed across a range of proteins.
Acute coronary syndrome — anoverview of current management
Authors: Baliga Vivek , Srinivasan Neil , Kearney Mark
Published: November 2009

Our series Prescribing in older people gives practical advice for successful management of the special problems faced by this age group. Here, the authors provide an overview of the current recommended management of acute coronary syndrome. Copyright © 2009 Wiley Interface Ltd
SMF report: the public's views on local healthcare variation
Authors: Chaplin Steve
Published: November 2009

The Social Market Foundation has conducted a telephone omnibus survey in England to determine the public's views on local and national healthcare strategies. Here, Steve Chaplin presents the findings of the survey and their implications for policy makers. Copyright © 2009 Wiley Interface Ltd
Laparoscopic subtotal hysterectomy versus laparoscopic total hysterectomy: a decade of experience
Authors: van Evert J. S. , Smeenk J. M. J. , Dijkhuizen F. P. H. L. J. , de Kruif J. H. , Kluivers K. B.
Published: November 2009

At present, there are only few data on the surgical outcomes of laparoscopic hysterectomy (LH). Up till now, it has been unclear whether there is a difference in number of complications among the subcategories of laparoscopic total hysterectomy and laparoscopic subtotal hysterectomy (LSH). Therefore, we have performed a retrospective analysis to evaluate the peri- and postoperative outcomes in women undergoing LSH versus LH. This multi-centre retrospective cohort study (Canadian Task Force classification II-2) was conducted in multi-centres (two teaching hospitals and one university medical centre) in the Netherlands, all experienced in minimally invasive gynaecology. In a multi-centre retrospective cohort study we compared the long-term outcomes of laparoscopic subtotal hysterectomy and laparoscopic total hysterectomy (including laparoscopic assisted vaginal hysterectomy, laparoscopic hysterectomy and total laparoscopic hysterectomy). All laparoscopic hysterectomies from the last 10 years (January 1998 till December 2007) were included. Patient characteristics, intra- and postoperative complications, operating time and duration of hospital stay were recorded. The minimum follow-up was 6 months. A total of 390 cases of laparoscopic hysterectomies were included in the analysis: 192 laparoscopic subtotal hysterectomies and 198 laparoscopic total hysterectomies. Patient characteristics such as age and parity were equal in the groups. The overall number of short-term and long-term complications was comparable in both groups: 17% and 15%. Short-term complications (bleeding, fever) were 3% in the LSH group and 12% in the LH group. Long-term complications were (tubal prolapse and cervical stump reoperations) 15% in the LSH group and 3% in the LH group. Laparoscopic subtotal hysterectomy as compared with the different types of laparoscopic total hysterectomy is associated with more long-term postoperative complications, whereas laparoscopic total hysterectomy is associated with more short-term complications.
Biomolecular Nano-Flow-Sensor to Measure Near-Surface Flow
Authors: Lee Sang-Wook , Kinoshita Haruyuki , Noji Hiroyuki , Fujii Teruo , Yamamoto Takatoki
Published: November 2009

We have proposed and experimentally demonstrated that the measurement of the near-surface flow at the interface between a liquid and solid using a 10 nm-sized biomolecular motor of F1-ATPase as a nano-flow-sensor. For this purpose, we developed a microfluidic test-bed chip to precisely control the liquid flow acting on the F1-ATPase. In order to visualize the rotation of F1-ATPase, several hundreds nanometer-sized particle was immobilized at the rotational axis of F1-ATPase to enhance the rotation to be detected by optical microscopy. The rotational motion of F1-ATPase, which was immobilized on an inner surface of the test-bed chip, was measured to obtain the correlation between the near-surface flow and the rotation speed of F1-ATPase. As a result, we obtained the relationship that the rotation speed of F1-ATPase was linearly decelerated with increasing flow velocity. The mechanism of the correlation between the rotation speed and the near-surface flow remains unclear, however the concept to use biomolecule as a nano-flow-sensor was proofed successfully.

(See supplementary material 1)
New Bending Algorithm for Field-Driven Molecular Dynamics
Authors: Chen Dao-Long , Chen Tei-Chen , Lai Yi-Shao
Published: November 2009

A field-driven bending method is introduced in this paper according to the coordinate transformation between straight and curved coordinates. This novel method can incorporate with the periodic boundary conditions in analysis along axial, bending, and transverse directions. For the case of small bending, the bending strain can be compatible with the beam theory. Consequently, it can be regarded as a generalized SLLOD algorithm. In this work, the bulk copper beam under bending is analyzed first by the novel bending method. The bending stress estimated here is well consistent to the results predicted by the beam theory. Moreover, a hollow nanowire is also analyzed. The zigzag traces of atomic stress and the corresponding 422 common neighbor type can be observed near the inner surface of the hollow nanowire, which values are increased with an increase of time. It can be seen that the novel bending method with periodic boundary condition along axial direction can provide a more physical significance than the traditional method with fixed boundary condition.
Photovoltaic Properties of p-Doped GaAs Nanowire Arrays Grown on n-Type GaAs(111)B Substrate
Authors: Cirlin G. E. , Bouravleuv A. D. , Soshnikov I. P. , Samsonenko Yu B. , Dubrovskii V. G. , Arakcheeva E. M. , Tanklevskaya E. M. , Werner P.
Published: November 2009

We report on the molecular beam epitaxy growth of Au-assisted GaAs p-type-doped NW arrays on the n-type GaAs(111)B substrate and their photovoltaic properties. The samples are grown at different substrate temperature within the range from 520 to 580 °C. It is shown that the dependence of conversion efficiency on the substrate temperature has a maximum at the substrate temperature of 550 °C. For the best sample, the conversion efficiency of 1.65% and the fill factor of 25% are obtained.
Comparing Process Efficiency in Reducing Steryl Glucosides in Biodiesel
Authors: Tang Haiying , De Guzman Rhet , Salley Steven , Ng K. Y. Simon
Published: November 2009

A significant obstacle to the commercial acceptance of biodiesel is the potential for filter plugging due to precipitates in the fuel. The majority of these precipitates can be attributed to either steryl glucosides (SGs) or monoacylglycerols in biodiesel. A GC–FID method to quantify minor components content in biodiesel is presented. The effectiveness of room temperature and cold soak filtration, adsorbent treatment, centrifuge, and vacuum distillation processes for SG removal was studied. The vacuum distillation process is the most effective method of removing the SG from biodiesel.
Connective tissue growth factor is induced in bleomycin‐induced skin scleroderma
Authors: Liu Shangxi , Taghavi Reza , Leask Andrew
Published: November 2009

The origin of fibrotic cells within connective tissue is unclear. For example, the extent to which microvascular pericytes contribute to the number of myofibroblasts present in dermal fibrosis in uncertain. Connective tissue growth factor (CTGF/CCN2) is a marker and mediator of fibrosis. In this report, we use an antibody recognizing CCN2 to assess the cell types in mouse dermis which express CCN2 in the bleomycin model of skin scleroderma. Control (PBS injected) and fibrotic (bleomycin‐injected) dermis was examined for CCN2, α‐smooth muscle actin (α‐SMA) (to detect myofibroblasts), and NG2 (to detect pericytes) expression. Consistent with previously published data, CCN2 expression was largely absent in the dermis of control mice. However, upon exposure to bleomycin, CCN2 was observed in the dermis. Cells that expressed CCN2 were α−SMA‐expressing myofibroblasts. Approximately 85% of myofibroblasts were NG2‐positive, CCN2‐expressing pericytes, indicating that pericytes significantly contributed to the presence of myofibroblasts in sclerotic dermis. Thus CCN2 is induced in fibrotic skin, correlating with the induction of myofibroblast induction. Moreover, CCN2‐expressing pericytes significantly contribute to the appearance of myofibroblasts in bleomycin‐induced skin scleroderma.
The molecular clockwork of a protein‐based circadian oscillator
Authors: Markson Joseph S. , O'Shea Erin K.
Published: November 2009

The circadian clock of the cyanobacterium Synechococcus elongatus PCC 7942 is governed by a core oscillator consisting of the proteins KaiA, KaiB, and KaiC. Remarkably, circadian oscillations in the phosphorylation state of KaiC can be reconstituted in a test tube by mixing the three Kai proteins and adenosine triphosphate. The in vitro oscillator provides a well‐defined system in which experiments can be combined with mathematical analysis to understand the mechanism of a highly robust biological oscillator. In this Review, we summarize the biochemistry of the Kai proteins and examine models that have been proposed to explain how oscillations emerge from the properties of the oscillator's constituents.
Opposing and uncoupling effects of mTOR and S6K1 in the regulation of endothelial tissue factor expression
Authors: Ming Xiu-Fen , Rajapakse Angana Gupta , Carvas João Miguel , Ruffieux Jean , Yang Zhihong
Published: November 2009

Rapamycin has been reported to enhance tissue factor (TF) expression. The present study investigated roles of mammalian target of rapamycin (mTOR) and its downstream S6K1 in this process. We showed here that, consistent with rapamycin, knocking‐down mTOR enhanced thrombin‐induced TF mRNA and protein levels, whereas silencing S6K1 mitigated up‐regulation of TF protein but not TF mRNA level. The enhanced TF protein level upon mTOR‐silencing was further augmented by over‐expression of a constitutively active S6K1 mutant and reduced by blocking RhoA, p38mapk or NF‐κB. The results reveal an opposing and uncoupling effect of mTOR and S6K1 in regulating TF expression.
Neuronal nicotinic acetylcholine receptor–cholesterol crosstalk in Alzheimer's disease
Authors: Barrantes Francisco J. , Borroni Virginia , Vallés Sofía
Published: November 2009

Alzheimer's disease (AD) is one of the most devastating diseases of the central nervous system (CNS). It is characterized by two neuropathological findings: amyloid plaques and neurofibrillary tangles. AD is also accompanied by an extensive functional deficit in the cholinergic system, involving the neuronal‐type nicotinic acetylcholine receptor (AChR). Furthermore there is increasing evidence showing a misregulation of cholesterol metabolism in the development of the disease. Since cholesterol affects AChR protein at multiple levels, the cognitive impairment and other neurological correlates of AD might be partly associated with an abnormal crosstalk between the receptor protein and the sterol in this synaptopathy.
Arc1p: Anchoring, routing, coordinating
Authors: Frechin Mathieu , Kern Daniel , Martin Robert Pierre , Becker Hubert Dominique , Senger Bruno
Published: November 2009

Accurate synthesis of aminoacyl‐tRNAs (aa‐tRNA) by aminoacyl‐tRNA synthetases (aaRS) is an absolute requirement for errorless decoding of the genetic code and is studied since more than four decades. In all three kingdoms of life aaRSs are capable of assembling into multi‐enzymatic complexes that are held together by auxiliary non‐enzymatic factors, but the role of such macromolecular assemblies is still poorly understood. In the yeast Saccharomyces cerevisiae, Arc1p holds cytosolic methionyl‐tRNA synthetase (cMRS) and glutamyl‐tRNA synthetase (cERS) together and plays an important role in fine tuning several cellular processes like aminoacylation, translation and carbon source adaptation.
Formation of the tRNALys packaging complex in HIV‐1
Authors: Kleiman Lawrence , Jones Christopher P. , Musier-Forsyth Karin
Published: November 2009

Human immunodeficiency virus 1 (HIV‐1) uses a host cell tRNALys,3 molecule to prime reverse transcription of the viral RNA genome into double‐stranded DNA prior to integration into the host genome. All three human tRNALys isoacceptors along with human lysyl‐tRNA synthetase (LysRS) are selectively packaged into HIV‐1. Packaging of LysRS requires the viral Gag polyprotein and incorporation of tRNALys additionally requires the Gag‐Pol precursor. A model that incorporates the known interactions between components of the putative packaging complex is presented. The molecular interactions that direct assembly of the tRNALys/LysRS packaging complex hold promise for the development of new anti‐viral agents.
Pollen–pistil interaction, pistil histology and seed production in A×B grain sorghum crosses under chilling field temperatures
Authors: CISNEROS-LÓPEZ M. E. , MENDOZA-ONOFRE L. E. , ZAVALETA-MANCERA H. A. , GONZÁLEZ-HERNÁNDEZ V. A. , MORA-AGUILERA G. , CÓRDOVA-TÉLLEZ L. , HERNÁNDEZ-MARTÍNEZ M.
Published: November 2009

Six pairs of isogenic lines of sorghum (Sorghum bicolor L. Moench) were sown in field plots in Montecillo, State of México (2240 m altitude), in 2005 and 2006. Crosses A (♀)×B (♂) were done in each pair. In A-lines, the length of pistil, stigma, style and ovary, as well as the ovary width, were measured. In B-lines, pollen diameter, viability (cytoplasm density) and production were evaluated. Pollen germination and pollen tube growth in the pistils of the A-lines, were quantified in vivo with aniline blue and epifluorescence 18 h after pollination (HAP), while fertilized pistils were counted at 96 HAP. Histological studies on both pollinated and non-pollinated pistils were performed in one male-sterile line. Seed yield, mean-seed weight, seeds per panicle and seed set (SS; seeds/flower/panicle) were determined at harvest. Pollen viability was the variable most related to pollen germination and pollen tube growth. Stigma receptivity was not associated with its morphology. Growth of the pollen tube in stigma, style and ovary was observed in the transmitting tissue 18 HAP, running parallel to the vascular tissue. Yield under chilling field temperatures (minimum average of 6 and 8°C) prevailing during flower development and pollination ranged from 7 to 12 g/panicle. The differences in seed production and SS among A×B crosses did not depend on the amount and viability of pollen.
Graph Partitioning via Adaptive Spectral Techniques
Authors: COJA-OGHLAN AMIN
Published: November 2009

In this paper we study the use of spectral techniques for graph partitioning. Let G = (V, E) be a graph whose vertex set has a ‘latent’ partition V1,. . ., Vk. Moreover, consider a ‘density matrix’ Ɛ = (Ɛvw)v, sw∈V such that, for v ∈ Vi and w ∈ Vj, the entry Ɛvw is the fraction of all possible Vi−Vj-edges that are actually present in G. We show that on input (G, k) the partition V1,. . ., Vk can (very nearly) be recovered in polynomial time via spectral methods, provided that the following holds: Ɛ approximates the adjacency matrix of G in the operator norm, for vertices v ∈ Vi, w ∈ Vj ≠ Vi the corresponding column vectors Ɛv, Ɛw are separated, and G is sufficiently ‘regular’ with respect to the matrix Ɛ. This result in particular applies to sparse graphs with bounded average degree as n = #V → ∞, and it has various consequences on partitioning random graphs.
Vicarious Graphs
Authors: ŁUCZAK TOMASZ , THOMASON ANDREW
Published: November 2009

Let H be some fixed graph. We call a graph Gvicarious for H if G is maximal H-free and, for every edge e of G, there is an edge f not in G such that G − e + f is also H-free. We demonstrate various properties of vicarious graphs and several examples are given. It is conjectured that a graph of order n which is vicarious for K3 has size at most (1/4 + o(1))().
Dominant language influence in acquisition and attrition of binding: Interpretation of the Korean reflexivecaki
Authors: KIM JI-HYE , MONTRUL SILVINA , YOON JAMES
Published: November 2009

This study investigates how the dominant language of Korean heritage speakers (English) influences Korean (minority language) in the domain of binding interpretations by comparing the performance of Korean immigrants in English dominant context with that of incomplete learners of Korean and L2 learners of Korean. Four groups (10 Korean immigrants, 17 simultaneous bilinguals, 14 late L2 learners, and 30 Korean native speakers) were tested. Differences between English and Korean in Governing Category and structural constraints were tested through a Truth Value Judgment Task with stories. Overall results showed that Korean immigrants (attriters) did not differ from Korean controls, while simultaneous bilinguals (incomplete learners) and late L2 learners of Korean showed behavior different from Korean control when two languages were different in their binding properties.
Masked translation priming: Varying language experience and word type with Spanish–English bilinguals
Authors: DAVIS CHRIS , SÁNCHEZ-CASAS ROSA , GARCÍA-ALBEA JOSÉ E. , GUASCH MARC , MOLERO MARGARITA , FERRÉ PILAR
Published: November 2009

Spanish–English bilingual lexical organization was investigated using masked cognate and non-cognate priming with the lexical decision task. In Experiment 1, three groups of bilinguals (Spanish dominant, English dominant and Balanced) and a single group of beginning bilinguals (Spanish) were tested with Spanish and English targets primed by cognate and non-cognate translations. All the bilingual groups showed cognate but not non-cognate priming. This cognate priming effect was similar in magnitude to the within-language repetition priming effect; it did not vary across participants who had different second-language acquisition histories, nor was the size of the priming effect modulated by the direction of the translation. The beginning bilingual group only showed cognate priming when the primes were in Spanish (L1) and the targets in English (L2). In Experiment 2, both form-related and unrelated word baselines were used with a single group of bilinguals. The results were the same as Experiment 1: cognate priming and no non-cognate priming. Experiment 3 examined the cognate priming effect with reduced orthographic and phonological overlap. Despite this reduced form overlap, it was found that the cognate effect was the same size as the within-language repetition effect. These results indicate that cognate translations are special and ways of modifying models of bilingual lexical processing to reflect this were considered.
State and parameter estimation of hydrologic models using the constrained ensemble Kalman filter
Authors: Wang Dingbao , Chen Yuguo , Cai Ximing
Published: November 2009

Data assimilation techniques, such as the Kalman filter (KF) and its extensions, update state variables based on the KF type of algorithms, but state‐space models usually have relevant physical laws or settings. The updated states by the KF may violate some physical constraints, which can be equality or inequality, and linear or nonlinear constraints. This paper presents three methods, the naive method, the projection method and the accept/reject method, to incorporate constraints into the ensemble Kalman filter (EnKF). Essentially, the projection method projects the updated ensemble members from the unconstrained EnKF to the feasible space characterized by the constraints. The accept/reject method tries to enforce the updated states to obey the constraints by resampling the observation error and model error. The three methods are applied to a conceptual hydrologic model for state estimation and sequential parameter learning, with specific treatment of inequality constraints. Both the reject/accept and projection methods perform better than the naive method which treats the hard constraint in a simple way and ignores other constraints. It is easy to implement the accept/reject method, the performance of which is comparable to the projection method regarding both the estimation quality and the computational time with the case study.
Remote sensing of suspended sediment concentration, flow velocity, and lake recharge in the Peace‐Athabasca Delta, Canada
Authors: Pavelsky Tamlin M. , Smith Laurence C.
Published: November 2009

The transport of fine sediment, carried in suspension by water, is central to the hydrology, geomorphology, and ecological functioning of river floodplains and deltas. An extensive new field data set for the Peace‐Athabasca Delta (PAD), Canada quantifies robust positive relationships between in situ suspended sediment concentration (SSC) and remotely sensed visible/near‐infrared reflectance. These relationships are exploited using SPOT and ASTER satellite images to map suspended sediment concentrations across the PAD for four days in 2006 and 2007, revealing strong variations in water sources and flow patterns, including flow reversals in major distributaries. Near‐daily monitoring with 276 MODIS satellite images tracks hydrologic recharge of floodplain lakes, as revealed by episodic infusions of sediment‐rich water from the Athabasca River. The timing and magnitude of lake recharge are linked to springtime water level on the Athabasca River, suggesting a system sensitive to changes in river flow regime. Moreover, recharge timing differentiates lakes that are frequently and extensively recharged from those recharged more rarely. Finally, we present a first estimation of river flow velocity based on remotely sensed SSC, though saturation may occur at velocities >0.6 m/s. Viewed collectively, the different remote sensing methodologies presented here suggest strong value for visible/near‐infrared remote sensing of suspended sediment to assess hydrologic and sediment transport processes in complex flow environments. Field observations including nephelometric turbidity, specific conductivity, water temperature, Secchi disk depth, suspended sediment concentration, and water level are archived at the Oak Ridge National Laboratory Distributed Active Archive Center for Biogeochemical Dynamics (available at http://daac.ornl.gov//HYDROCLIMATOLOGY/guides/PAD.html).