bluuebunny/crossref_metadata_2025 huggingface dataset:
No role for human papillomavirus in esophageal squamous cell carcinoma in China
Authors: Koshiol Jill , Wei Wen‐Qiang , Kreimer Aimee R. , Chen Wen , Gravitt Patti , Ren Jian‐Song , Abnet Christian C. , Wang Jian‐Bing , Kamangar Farin , Lin Dong‐Mei , von Knebel‐Doeberitz Magnus , Zhang Yu , Viscidi Raphael , Wang Guo‐Qing , Gillison Maura L. , Roth Mark J. , Dong Zhi‐Wei , Kim Esther , Taylor Philip R. , Qiao You‐Lin , Dawsey Sanford M.
Published: November 2009

Certain regions of China have high rates of esophageal squamous cell carcinoma (ESCC). Previous studies of human papillomavirus (HPV), a proposed causal factor, have produced highly variable results. We attempted to evaluate HPV and ESCC more definitively using extreme care to prevent DNA contamination. We collected tissue and serum in China from 272 histopathologically‐confirmed ESCC cases with rigorous attention to good molecular biology technique. We tested for HPV DNA in fresh‐frozen tumor tissue using PCR with PGMY L1 consensus primers and HPV16 and 18 type‐specific E6 and E7 primers, and in formalin‐fixed paraffin‐embedded tumor tissue using SPF10 L1 primers. In HPV‐positive cases, we evaluated p16INK4a overexpression and HPV E6/E7 seropositivity as evidence of carcinogenic HPV activity. β‐globin, and thus DNA, was adequate in 98.2% of the frozen tumor tissues (267/272). Of these, 99.6% (95% confidence interval (CI) = 97.9–100.0%) were negative for HPV DNA by PGMY, and 100% (95% CI = 98.6–100%) were negative by HPV16/18 E6/E7 PCR. In the corresponding formalin‐fixed paraffin‐embedded tumor specimens, 99.3% (95% CI = 97.3–99.9%) were HPV negative by SPF10. By PGMY, 1 case tested weakly positive for HPV89, a noncancer causing HPV type. By SPF10, 2 cases tested weakly positive: 1 for HPV16 and 1 for HPV31. No HPV DNA‐positive case had evidence of HPV oncogene activity as measured by p16INK4a overexpression or E6/E7 seropositivity. This study provides the most definitive evidence to date that HPV is not involved in ESCC carcinogenesis in China. HPV DNA contamination cannot be ruled out as an explanation for high HPV prevalence in ESCC tissue studies with less stringent tissue procurement and processing protocols.
Behaviors of ATP‐dependent chromatin remodeling factors during maturation of bovine oocytes in vitro
Authors: Wee Gabbine , Shin Sang‐Tae , Koo Deog‐Bon , Han Yong‐Mahn
Published: November 2009

The mammalian oocyte undergoes dynamic changes in chromatin structure to reach complete maturation. However, little known is about behaviors of ATP‐dependent chromatin remodeling factors (ACRFs) during meiosis. Here, we found that respective ACRFs may differently behave in the process of oocyte maturation in the bovine. All ACRFs interacted with oocytic chromatin at the germinal vesicle (GV) stage. Mi‐2 and hSNF2H disappeared from GV‐chromatin within 1 hr of in vitro culture whereas Brg‐1 and BAF‐170 were retained throughout germinal vesicle break down (GVBD). Brg‐1 was localized on the condensed chromatin outside, whereas BAF‐170 was entirely excluded from condensed chromatin. Thereafter, Brg‐1 and BAF‐170 interacted with metaphase I and metaphase II chromosomes. These results imply that Mi‐2 and hSNF2H may initiate the meiotic resumption, and Brg‐1 and BAF‐170 may support chromatin condensation during meiosis. In addition, DNA methylation and methylation of histone H3 at lysine 9 (H3K9) seem to be constantly retained in the oocyte chromatin throughout in vitro maturation. Inhibition of ACRF activity by treatment with the inhibitor apyrase led to retarded chromatin remodeling in bovine oocytes, thereby resulting in poor development of fertilized embryos. Therefore, these results indicate that precise behaviors of ACRFs during meiosis are critical for nuclear maturation and subsequent embryonic development in the bovine. Mol. Reprod. Dev. 77: 126–135, 2010. © 2009 Wiley‐Liss, Inc.
Are single‐gift committed donors different from their multiple‐gift counterparts?
Authors: Shen Anyuan , Tsai Chih‐Yang
Published: November 2009

Committed donors who keep giving every year are a key asset for nonprofit organizations because they provide a steady funding source and return a higher lifetime value. We distinguish between committed donors who give only one gift per year (single‐gift (SG) donors) and those who give multiple gifts in at least some year (multiple‐gift (MG) donors).

In this paper, we study whether SG donors and MG donors follow different longitudinal patterns of gift‐giving in four consecutive years. We theorize that a donor's yearly gift amount is an indication of his or her willingness to give (WTG) to the organization and may be explained in terms of his or her intrinsic willingness to give (IWTG) and extrinsic willingness to give (EWTG) for that year. We test our theory with data from a leading US nonprofit organization and find that SG donors and MG donors would follow different longitudinal patterns:

While SG donors and MG donors would start off at a similar level of WTG in year 1 and would both increase WTG in subsequent years, MG donors would record a higher rate of increase than SG donors.

IWTG and EWTG would have different relative importance as determinants of the observed yearly giving level: MG donors depend on both IWTG and EWTG whereas SG donors largely depend on IWTG rather than EWTG to determine how much to give in a year.

Our findings suggest that different strategies are needed to manage SG donors and MG donors to sustain and grow annual contributions. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of maternal BMI on genetic sonography in the FaSTER trial
Authors: Aagaard‐Tillery Kjersti M. , Flint Porter T. , Malone Fergal D. , Nyberg David A. , Collins Jamie , Comstock Christine H. , Hankins Gary , Eddleman Keith , Dugoff Lorraine , Wolfe Honor M. , D'Alton Mary E.
Published: November 2009

Objective

We sought to evaluate the influence of maternal body mass index (BMI) on sonographic detection employing data from the FaSTER trial.

Method

Unselected singleton pregnancies underwent detailed genetic sonogram to evaluate for structural fetal anomalies and soft markers for aneuploidy. BMI (kg/m2) were calculated from reported initial visit values. Sensitivity, specificity, false positive and false negative rates (FPR and FNR), likelihood ratio, detection rates, and a missed diagnosis rate (MDR: FNR + marker recorded as ‘missing’/N) were calculated.

Results

Eight thousand five hundred and fifty‐five patients with complete BMI information had detailed genetic sonography. A lower sensitivity with an elevated FNR and MDR was observed in obese women for multiple aneuploid markers (e.g. ≥2 markers 32% sensitivity with 68% FNR among BMI <25 vs 22% and 78% among BMI >30). Similarly, the detection rate for cardiac anomalies among women at BMI <25 was higher (21.6%) at a significantly lower FPR (78.4%; 95% CI 77.3–79.5%) in comparison to obese women (8.3% with FPR 91.7%; 95% CI 90.1–93.2%). In a logistic regression model, maternal obesity significantly decreased the likelihood of sonographic detection of common anomalies (adjusted OR 0.7; 95% CI 0.6–0.9; p = 0.001).

Conclusion

The performance of second trimester genetic sonography is influenced by obesity, with a significantly higher MDR for multiple minor markers and lower likelihood for detecting common anomalies. Copyright © 2009 John Wiley & Sons, Ltd.
Associations between leisure‐time physical activity and health‐related quality of life among adolescent and adult survivors of childhood cancers
Authors: Paxton Raheem J. , Jones Lee W. , Rosoff Philip M. , Bonner Melanie , Ater Joann L. , Demark‐Wahnefried Wendy
Published: November 2009

Objective: Survivors of childhood cancer are at an increased risk for reduced quality of life (QOL), yet few studies have explored factors associated with improving health‐related QOL (HRQOL) in this population. We thus explored the relationship between physical activity (PA) and HRQOL among survivors of childhood cancer.

Methods: A total of 215 survivors of childhood lymphoma, leukemia, and central nervous system cancers completed mailed surveys that elicited information regarding leisure‐time PA (LTPA) measured in metabolic equivalents, HRQOL, and diagnostic and demographic factors. Correlations and adjusted regression models were used to explore the relationship between LTPA and HRQOL.

Results: In the total sample, modest, yet significant linear associations were observed between LTPA and overall HRQOL (β=0.17, p<0.01), as well as each of the respective subscales (β=0.11−0.23 and p's<0.05 to <0.001). Among adolescent survivors of childhood cancer, LTPA was significantly associated with overall HRQOL (β=0.27), cancer worry (β=0.36), cognitive function (β=0.32), body appearance (β=0.29), and social function (β=0.27) (all p's<0.05). Among adult survivors of childhood cancer, LTPA was only significantly associated with physical function (β=0.28, p<0.001).

Conclusions: Significant associations exist between LTPA and HRQOL; however, the association was stronger and observed in more domains for adolescent survivors of childhood cancer. More research is needed to determine the antecedents and consequences of PA in this population. Copyright © 2010 John Wiley & Sons, Ltd.
Identification of metabolites of adonifoline, a hepatotoxic pyrrolizidine alkaloid, by liquid chromatography/tandem and high‐resolution mass spectrometry
Authors: Xiong Aizhen , Yang Li , He Yuqi , Zhang Fang , Wang Jun , Han Han , Wang Changhong , Bligh S. W. Annie , Wang Zhengtao
Published: November 2009

Hepatotoxic pyrrolizidine alkaloid (HPA)‐containing plants have always been a threat to human and livestock health worldwide. Adonifoline, a main HPA inSenecio scandensBuch.‐Ham. ex D. Don (Qianli guang), was used officially as an infusion in cases of oral and pharyngeal infections in China. In this study in vivometabolism of adonifoline was studied for the first time by identifying the metabolites of adonifoline present in bile, urine and feces of rats using liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MSn) (ion trap) as well as liquid chromatography/electrospray ionization high‐resolution mass spectrometry (LC/ESI‐HRMS) (quadrupole‐time of flight). In total 19 metabolites were identified and, among them, retronecine‐N‐oxides were confirmed by matching their fragmentation patterns with their fully characterized synthetic compounds. These metabolites are all involved in both phase I and phase II metabolic processes and the principalin vivometabolism pathways of adonifoline were proposed. Copyright © 2009 John Wiley & Sons, Ltd.
Efficiency robust statistics for genetic linkage and association studies under genetic model uncertainty
Authors: Joo Jungnam , Kwak Minjung , Chen Zehua , Zheng Gang
Published: November 2009

When testing genetic linkage and association, test statistics that follow a normal or Chi‐square distributions are often used. These statistics are usually derived under a specific mode of inheritance (genetic model). Common genetic models include, but not limited to, the recessive, additive, multiplicative, and dominant models. For many diseases, their underlying genetic models are often unknown. Instead, a family of scientifically plausible genetic models may be available, which includes the four commonly used models. Hence, the optimal test is not available. Employing a single test statistic which is optimal for one model may suffer from substantial loss of power when the model is misspecified. In this situation efficient robust tests are useful. In this tutorial, we first review several commonly used robust statistics, including maximin efficency robust tests, maximal tests, and constrained likelihood ratio tests for three common designs in genetic studies: (i) linkage analysis using affected sib‐pairs, (ii) association studies using parents–offspring trios, and (iii) case–control association studies (unmatched and matched). Codes in the R statistical language for applying these robust statistics to test for linkage and association are presented with examples. We also provide some comparisons of the performance of the various robust tests via simulation studies. Guidelines for applications are also given for each study design. Finally, applications of robust tests to genome‐wide association studies and meta‐analysis are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
A lazy approach to symmetry reduction
Authors: Wahl Thomas , D’Silva Vijay
Published: November 2009

Symmetry reduction
is a technique to counter state explosion for systems with regular structure. It relies on idealistic assumptions about indistinguishable components, which in practice may only be similar. In this article, we present a flexible, lazy approach to symmetry-reducing a structure without any prior knowledge about its global symmetry. Instead of a-priori checking for compliance with symmetry conditions, each encountered state is annotated on the fly with information about how symmetry is
violated
along the path leading to it. The method naturally favors “very symmetric” systems: more similarity among the components leads to greater compression. A notion of
subsumption
is used to prune the annotated search space during exploration. Previous solutions to the approximate symmetry reduction problem are restricted to specific types of asymmetry, such as up to bisimilarity, or incur a large overhead, either during preprocessing of the structure or during the verification run. In contrast, the strength of our method is its balance between ease of implementation and algorithmic flexibility. We include analytic and experimental results that witness its efficiency.
Looped Penrose Drain for Minimally Invasive Treatment of Complex Superficial Abscesses of the Hand
Authors: Jandali Shareef , Ugrinich Marija , Chang Benjamin
Published: November 2009

Complex superficial abscesses are a common occurrence that traditionally have been treated by making relatively large incisions over the surface of the abscess, in order to ensure drainage and access for packing and dressing changes. The authors outline a minimally invasive technique that can be used for draining complex subcutaneous abscesses that extend over a large surface area. It is a simple technique utilizing multiple small incisions and looped penrose drains. This technique has been found to be very effective in many areas of the body and has multiple advantages over traditional incision, drainage, gauze packing, and dressing changes.
Lipid Profiles of Tunisian Coriander (Coriandrum sativum) Seed
Authors: Sriti Jazia , Wannes Wissem Aidi , Talou Thierry , Mhamdi Baya , Cerny Muriel , Marzouk Brahim
Published: November 2009

Coriander (Coriandrum sativum L.) seeds were harvested from the region of Korba (North‐East Tunisia) in order to characterize their fatty acids, phytosterols, tocopherols and tocotrienols (tocols) profiles. Nine fatty acids, with petroselinic acid accounting for 76.6% of the total fatty acids, followed by linoleic, oleic and palmitic acids, accounting for 13.0, 5.4 and 3.4%, respectively, of the total fatty acids were identified. Neutral lipids (NLs) were mainly composed of triacylglycerols (98.4%). Polar lipids were mainly composed of phosphatidylcholine as the major phospholipid (PL) subclass, whereas digalactosyldiacylglycerol was the major galactolipid (GL). Total sterols content was estimated to be 36.93 mg/g oil. Stigmasterol accounted for 29.5% of the total sterols. Other representative sterols were β‐sitosterol, Δ7‐stigmasterol and Δ5, 24‐stigmastadienol, which accounted for 24.8, 16.3 and 9.2%, respectively. Gamma‐tocotrienol was the predominant tocol at 238.40 μg/g seed oil. This was equivalent to 72.8% of the total tocols followed by γ‐tocopherol (8.06%) and α‐tocopherol (7.6%).
A Microfluidic Cartridge System for Multiplexed Clinical Analysis
Authors: Lawi Walson , Wiita Chris , Snyder Steven T. , Wei Fang , Wong David , Wong Pak Kin , Liao Joseph C. , Haake David , Gau Vincent
Published: November 2009

Cartridge-based microfluidics is a promising technology for clinical diagnostics. By miniaturizing the fluid-handling processes required for genomic and proteomic analyses, reagent and specimen volume is minimized along with the size of the system. We demonstrate an automated microfluidic system capable of performing six multiplexed genomic and proteomic analyses simultaneously, by means of an integrated electrochemical sensor and embedded controls.
Automation of the SomaLogic Proteomics Assay: A Platform for Biomarker Discovery
Authors: Keeney Tracy R. , Bock Christopher , Gold Larry , Kraemer Stephan , Lollo Bridget , Nikrad Malti , Stanton Martin , Stewart Alex , Vaught Jonathan D. , Walker Jeffrey J.
Published: November 2009

At SomaLogic, we have embarked on an ambitious program of clinical studies using a novel aptamerbased proteomics technology to discover biomarkers and develop new tools to diagnose, understand, and treat human disease. As part of this program, we designed and implemented an automated assay for its highly multiplexed proteomics discovery platform. The performance of the automated assay was validated in a study that compared the automated assay to the specifications of an established manual method. Results showed that the automated method performed to the required specifications, and that the automation system improved the efficiency, productivity, and economics of our biomarker discovery program.
High-Pressure/High-Temperature Microreactors for Nanostructure Synthesis
Authors: Marre Samuel , Baek Jinyoung , Park Jongnam , Bawendi Moungi G. , Jensen Klavs F.
Published: November 2009

Chemically synthesized nanomaterials, such as nanocrystalline quantum dots, are being considered as the active element in many applications, including photovoltaics, displays, and biochem sensing. To realize the promise of these devices, it will be critical to have an efficient, reproducible synthesis technique of the nanostructures. Currently, nanoparticles are synthesized in a batch mode in small volumes, which is appropriate for studying the fundamental properties of nanosized structures and for developing proof of principle device structures. However, batch synthesis suffers from control of size, size distribution, and quality of the nanomaterial from batch to batch. Moreover, there is an inherent difficulty in scaling up to quantities more reasonable for device development and optimization. Continuous-flow reactors based on microfluidics (microreactors) integrated with heaters and fluid control elements offer a solution to these problems and additional advantages. We describe continuous synthesis of nanostructures in microfluidic systems consisting of multiple sub—millimeter-sized channels in which fluid flows continuously and chemical reactions take place. The small reaction volumes combined with the high heat and mass transfer rates enable reactions to be performed under more controlled conditions with higher yields than can typically be achieved with conventional reactors. Moreover, manipulation of reaction parameters, while the reaction proceeds, allows optimization of synthesis conditions. The ability to work at elevated temperatures and pressures while confining potentially toxic, high reactive starting materials will become important for the synthesis of novel nanostructured materials.
A Method for Identifying Small-Molecule Aggregators Using Photonic Crystal Biosensor Microplates
Authors: Chan Leo L. , Lidstone Erich A. , Finch Kristin E. , Heeres James T. , Hergenrother Paul J. , Cunningham Brian T.
Published: November 2009

Small molecules identified through high-throughput screens are an essential element in pharmaceutical discovery programs. It is now recognized that a substantial fraction of small molecules exhibit aggregating behavior leading to false positive results in many screening assays, typically due to nonspecific attachment to target proteins. Therefore, the ability to efficiently identify compounds within a screening library that aggregate can streamline the screening process by eliminating unsuitable molecules from further consideration. In this work, we show that photonic crystal (PC) optical biosensor microplate technology can be used to identify and quantify small-molecule aggregation. A group of aggregators and nonaggregators were tested using the PC technology, and measurements were compared with those gathered by three alternative methods: dynamic light scattering (DLS), an α-chymotrypsin colorimetric assay, and scanning electron microscopy (SEM). The PC biosensor measurements of aggregation were confirmed by visual observation using SEM, and were in general agreement with the α-chymotrypsin assay. DLS measurements, in contrast, demonstrated inconsistent readings for many compounds that are found to form aggregates in shapes, very different from the classical spherical particles assumed in DLS modeling. As a label-free detection method, the PC biosensor aggregation assay is simple to implement and provides a quantitative direct measurement of the mass density of material adsorbed to the transducer surface, whereas the microplate-based sensor format enables compatibility with high-throughput automated liquid-handling methods used in pharmaceutical screening.
Onset of convection over a transient base-state in anisotropic and layered porous media
Authors: RAPAKA SAIKIRAN , PAWAR RAJESH J. , STAUFFER PHILIP H. , ZHANG DONGXIAO , CHEN SHIYI
Published: November 2009

The topic of density-driven convection in porous media has been the focus of many recent studies due to its relevance as a long-term trapping mechanism during geological sequestration of carbon dioxide. Most of these studies have addressed the problem in homogeneous and anisotropic permeability fields using linear-stability analysis, and relatively little attention has been paid to the analysis for heterogeneous systems. Previous investigators have reduced the governing equations to an initial-value problem and have analysed it either with a quasi-steady-state approximation model or using numerical integration with arbitrary initial perturbations. Recently, Rapakaet al. (J. Fluid Mech., vol. 609, 2008, pp. 285–303) used the idea of non-modal stability analysis to compute the maximum amplification of perturbations in this system, optimized over the entire space of initial perturbations. This technique is a mathematically rigorous extension of the traditional normal-mode analysis to non-normal and time-dependent problems. In this work, we extend this analysis to the important cases of anisotropic and layered porous media with a permeability variation in the vertical direction. The governing equations are linearized and reduced to a set of coupled ordinary differential equations of the initial-value type using the Galerkin technique. Non-modal stability analysis is used to compute the maximum growth of perturbations along with the optimal wavenumber leading to this growth. We show that unlike the solution of the initial-value problem, results obtained using non-modal analysis are insensitive to the choice of bottom boundary condition. For the anisotropic problem, the dependence of critical time and wavenumber on the anisotropy ratio was found to be in good agreement with theoretical scalings proposed by Ennis-Kinget al. (Phys. Fluids, vol. 17, 2005, paper no. 084107). For heterogeneous systems, we show that uncertainty in the permeability field at low wavenumbers can influence the growth of perturbations. We use a Monte Carlo approach to compute the mean and standard deviation of the critical time for a sample permeability field. The results from theory are also compared with finite-volume simulations of the governing equations using fully heterogeneous porous media with strong layering. We show that the results from non-modal stability analysis match extremely well with those obtained from the simulations as long as the assumption of strong layering remains valid.
Bistability between a stationary and an oscillatory dynamo in a turbulent flow of liquid sodium
Authors: BERHANU M. , GALLET B. , MONCHAUX R. , BOURGOIN M. , ODIER PH. , PINTON J.-F. , PLIHON N. , VOLK R. , FAUVE S. , MORDANT N. , PÉTRÉLIS F. , AUMAÎTRE S. , CHIFFAUDEL A. , DAVIAUD F. , DUBRULLE B. , RAVELET F.
Published: November 2009

We report the first experimental observation of a bistable dynamo regime. A turbulent flow of liquid sodium is generated between two disks in the von Kármán geometry (VKS experiment). When one disk is kept at rest, bistability is observed between a stationary and an oscillatory magnetic field. The stationary and oscillatory branches occur in the vicinity of a codimension-two bifurcation that results from the coupling between two modes of magnetic field. We present an experimental study of the two regimes and study in detail the region of bistability that we understand in terms of dynamical system theory. Despite the very turbulent nature of the flow, the bifurcations of the magnetic field are correctly described by a low-dimensional model. In addition, the different regimes are robust; i.e. turbulent fluctuations do not drive any transition between the oscillatory and stationary states in the region of bistability.
Transcatheter closure of the arterial duct without arterial access
Authors: Willcoxson Fiona E , Viswanathan Sangeetha , Thomson John D.R. , Gibbs John L.
Published: November 2009

Objective

To evaluate the safety and efficacy of transcatheter occlusion of the arterial duct without femoral arterial catheterization.

Background

Patent arterial ducts have been closed percutaneously since the 1960s. It remains standard practice to use arterial access for aortography before, during, and after implantation of the device. Femoral arterial catheterisation has well recognised complications, and should be avoided unless absolutely necessary.

Methods

We reviewed prospectively collected data relating to 389 occlusions of the arterial duct performed consecutively between 1994 and 2004. We inserted Cook detachable coils in 288 instances using the Amplatzer duct occluder in the remaining 101. Information was obtained regarding procedural success, displacement of the device, and re-intervention. We have followed out patients for a median of 1.15 years in those closed with the Amplatzer device, and 1.09 years in those closed with a coil.

Results

In the patients in whom we used coils, occlusion was possible in 75% using venous access alone. We reintervened in 25 patients, because of embolisation of the device in 6, haemolysis in 5, and residual shunting in 14. On follow-up, complete occlusion had been achieved in 98%. We found trivial stenosis of the left pulmonary artery in 3 patients. When using the Amplatzer device, closure using venous access alone was achieved in 82%, and 2 patients required reintervention because of embolisation of the device. Complete occlusion had been achieved in all patients as judged by follow-up at 1 year, and 2 patients had trivial stenosis of the left pulmonary artery.

Conclusion

Arterial catheterisation is unnecessary in the great majority of patients undergoing occlusion of the arterial duct. Use of venous catheterisation alone is safe, and does not appear to increase the risk of device-related complications.
Megavoltage versus kilovoltage image guidance for efficiency and accuracy in head and neck IMRT
Authors: Willis D. , Fox C. , Haworth A. , Rolfo A. , Herschtal A. , Kron T.
Published: November 2009

Accurate patient positioning is vitally important in intensity modulated radiation therapy (IMRT) for head and neck (H&N) cancer. The introduction of kilovoltage (kV) on-board imaging (OBI) at our centre was anticipated to improve the accuracy and efficiency of H&N IMRT patient position verification over traditional megavoltage (MV) electronic portal imaging (EPI). This study compares these imaging systems with a phantom accuracy study and retrospective analysis of imaging workload in H&N IMRT at our centre. Six therapists performed online evaluation of phantom images, and residual positional errors for each system were recorded. The largest residual error was 1 mm for OBI and 3 mm for EPI. The estimated improvement in residual error in OBI over EPI was 0.57 mm (95% confidence interval 0.33–0.81 mm), suggesting treatment staff would be better able to detect set-up deviations with OBI. Electronic treatment records of 20 H&N IMRT patients (10 verified daily with MV EPI and 10 with kV OBI) were analysed. Mean imaging session duration was 9.51 min for EPI and 9.76 min for OBI. Analysis found no evidence of an effect on duration due to the imaging system used for this subset of patients (p = 0.664).
Development of radioresistance in drug resistant human MCF-7 breast cancer cells
Authors: Kars Meltem Demirel , Iseri Özlem Darcansoy , Ural Ali Ugur , Avcu Ferit , Beyzadeoglu Murat , Dirican Bahar , Gündüz Ufuk
Published: November 2009

Background and purpose: Radiotherapy is used for the treatment of malignant tumours, and may be used as the primary therapy. It is also common to combine radiotherapy with surgery, chemotherapy, hormone therapy or some combination of them. Even if the tumour is treated intensively, women diagnosed with breast cancer may develop a recurrence. Most recurrences may be in the form of distant metastases, development of multi-drug resistance phenotype or both together. This study demonstrated that some of the multi-drug resistant cancer cells may also become radioresistant.

Materials and Methods: Chemoresistance in paclitaxel (MCF-7/Pac), docetaxel (MCF-7/Doc), vincristine (MCF-7/Vinc), doxorubicin (MCF-7/Dox) and zoledronic acid (MCF-7/Zol) resistant MCF-7 cells were demonstrated by XTT assay. MDR1 gene expression was detected by real-time PCR in human MCF-7 breast cancer cells. Drug resistant and sensitive cells were exposed to γ-radiation and development of radioresistance was investigated.

Results: Results have indicated that paclitaxel, docetaxel, vincristine, doxorubicin and zoledronic acid–selected cells gained varying degrees of resistance to their selective drugs when compared with original MCF-7/S. MCF-7/Pac, MCF-7/Doc, MCF-7/Vinc and MCF-7/Dox cells have all acquired MDR1 expression. Among the resistant sub-lines, MCF-7/Pac and MCF-7/Doc cells were significantly cross-resistant to irradiation compared to the sensitive cells.

Conclusion: MCF-7/Pac and MCF-7/Doc cell lines were found radioresistant to γ-radiation. On the contrary, doxorubicin, vincristine and zoledronic acid resistant cancer cells were still sensitive to radiation.
Geoscience Field Education: A Recent Resurgence
Authors: Whitmeyer Steven J. , Mogk David W.
Published: November 2009

Field education traditionally has been an integral component of undergraduate geoscience curricula. Students have learned the fundamentals of field techniques during core geology courses and have honed their field credentials during class‐specific field trips, semester‐long field courses, and capstone summer field camps. In many geoscience departments, field camp remains a graduation requirement, and more than 100 field camps currently are offered by U.S. universities and colleges (see http://geology.com/field‐camp.shtml).

During the past several decades, however, many geoscience departments have moved away from traditional geologic fieldwork and toward a broader theoretical and laboratory‐intensive focus that encompasses a range of subdisciplines. Trends that have influenced these shifts include (1) the decline in the late twentieth century of the petroleum and mining industries, which have consistently championed the values of fieldwork; (2) a decrease in the number of professional jobs that incorporate field mapping; (3) a decline in the number of geoscience majors nationwide [American Geological Institute (AGI), 2009]; and (4) barriers to fieldwork, including time requirements, cost, liability, and decreasing access to field sites.
Global Satellite Vegetation Monitoring: Long Term Global Monitoring of Vegetation Variables Using Moderate Resolution Satellites; Missoula, Montana, 16–19 June 2009
Authors: Nightingale Joanne , Running Steven
Published: November 2009

The fourth global vegetation workshop illuminated critical issues related to the current status and future of satellite vegetation monitoring in the climate change and carbon‐trading era. About 120 scientists representing 12 countries attended the 3‐day workshop.

Plenary talks were given by distinguished remote sensing/ecosystem scientists. John Townshend (University of Maryland) presented his views on the current challenges in global remote sensing. Richard Waring (Oregon State University) offered new ecological insights to improve predictions of terrestrial carbon balances from satellite data sets. Compton Tucker (NASA Goddard Space Flight Center) gave a synopsis of land observations, climate data gaps, and essential climate variables for global vegetation monitoring.
Environmental Responses to a Land Reclamation Project in South Korea
Authors: Son SeungHyun , Wang Menghua
Published: November 2009

In 1991, South Korea embarked on an ambitious project to reclaim nearly 401 square kilometers of land and tidal flats from the Yellow Sea by building a system of two dikes extending 33 kilometers across the mouths of the Dongjin and Mangyeong rivers, offshore of the Saemangeum district (see Figures 1a and 1b). Called the Saemangeum Reclamation Project, the endeavor will allot about 283 square kilometers of the reclaimed land for crop production (mostly rice) through irrigation of the rivers' estuaries, which will be extended by about 23 kilometers when the bay fills up. The rest of the reclaimed land will be a water reservoir for agricultural use [Lie et al., 2008].

The construction of the Saemangeum Reclamation Project's northern dike was completed in June 2003; the southern dike was finished in April 2006. Two gaps in the southern dike allow water exchange, and two gates control the water level inside the dikes. The reclamation project, the biggest such endeavor in South Korea, is expected to be completed around 2030.
Climate Change: The Need to Consider Human Forcings Besides Greenhouse Gases
Authors: Pielke Roger , Beven Keith , Brasseur Guy , Calvert Jack , Chahine Moustafa , Dickerson Russell R. , Entekhabi Dara , Foufoula‐Georgiou Efi , Gupta Hoshin , Gupta Vijay , Krajewski Witold , Krider E. Philip , Lau William K. M. , McDonnell Jeff , Rossow William , Schaake John , Smith James , Sorooshian Soroosh , Wood Eric
Published: November 2009

Humans are recognized as having a major role in influencing environmental variability and change, including their influence on the climate system. To advance scientists' understanding of the role of humans within the climate system, there remains a need to resolve which of the following three hypotheses is correct:

Hypothesis 1: Human influence on climate variability and change is of minimal importance, and natural causes dominate climate variations and changes on all time scales. In coming decades, the human influence will continue to be minimal.
Propagation characteristics of Pi 2 pulsations observed at high‐ and low‐latitude MAGDAS/CPMN stations: A statistical study
Authors: Uozumi Teiji , Abe S. , Kitamura K. , Tokunaga T. , Yoshikawa A. , Kawano H. , Marshall R. , Morris R. J. , Shevtsov B. M. , Solovyev S. I. , McNamara D. J. , Liou K. , Ohtani S. , Itonaga M. , Yumoto K.
Published: November 2009

The objective of this study is to understand better the propagation of Pi 2 waves in the nighttime region. We examined Pi 2 oscillations that showed high correlation between high‐ and low‐latitude Magnetic Data Acquisition System/Circum Pan‐Pacific Magnetometer Network stations (correlation coefficient: ∣γ∣ ≥ 0.75). For each horizontal component (H and D) we examined the magnetic local time (MLT) dependence of the delay time of high‐latitude Pi 2 oscillations that corresponds to the highest correlation with the low‐latitude Pi 2 oscillation. We found the delay time of the high‐latitude H showed remarkable MLT dependence, especially in the premidnight sector: we found that in the premidnight sector the high‐latitude H oscillation tends to delay from the low‐latitude oscillation (<100 s). On the other hand, the delay time of the high‐latitude D oscillation was not significant (∼±10 s) in the entire nighttime sector. We propose a Pi 2 propagation model to explain the observed delay time of high‐correlation high‐latitude H. The model quantitatively explains the trend of the event distribution. We also examined the spatial distribution of high‐correlation Pi 2 events relative to the center of auroral breakups. It was found that the high‐correlation Pi 2 events tend to occur away from the center of auroral breakups by more than 1.5 MLT. The present result suggests that the high‐correlation H component Pi 2 oscillations at high latitude are a manifestation of forced Alfvén waves excited by fast magnetosonic waves.
Conceptions of Control and it Artefacts: An Institutional Account of the Amazon Rainforest Monitoring System
Authors: Rajão Raoni , Hayes Niall
Published: November 2009

Based on Fligstein's (1990) work on ‘conceptions of control’ (broad managerial paradigms), this paper provides an analysis of the ways in which information technology (IT) artefacts shape and are shaped by institutional contexts. Specifically, we report on primary and secondary empirical data that spans a 44-year period pertaining to the uses made of the Amazon rainforest monitoring system (a set of satellite-based geographic information systems). This paper argues that: (1) the process of institutional change is conflictual, emergent and contested; (2) the design and use of IT artefacts tend to reflect the currently dominant conceptions of control; (3) that IT artefacts that emerge within a specific conception of control can be later reconfigured to serve the interests of other conceptions of control; (4) and finally, IT artefacts might unintentionally reinforce alternate conceptions of control and lead to institutional change.
Institutionalizing Enterprise Resource Planning in the Saudi Steel Industry: A Punctuated Socio-Technical Analysis
Authors: Lyytinen Kalle , Newman Mike , Al-Muharfi Abdul-Rahman A
Published: November 2009

In this article, we analyze institutionalization as a process of transferring and stabilizing material artifacts and routines in the form of enterprise resource planning (ERP) systems. Although past studies have analyzed institutionalization as structuring around scripts or discourse moves, we emphasize the material role of artifacts and routines as carriers of institutional logics. In addition, insitutionalization is not linear and incremental, but goes through sudden, nonlinear disruptions. To this end, we apply punctuated socio-technical information system change (PSIC) model that draws upon Gersick's model of change to identify and trace moves that are critical during the institutionalization. The model accounts for ERP institutionalization by chronicling complex interactions between socio-technical elements in the implementation system, the work system, and organizational and environmental context which together account for the institutionalization outcome. We use the model to analyze a longitudinal case covering 11 years (1993–2004) of ERP implementation processes in a large Saudi steel firm. Our analysis shows that the proposed material and punctuated lens toward institutionalization offers rich insights how and why ERP systems become institutions and why their institutionalization is difficult and unfolds in unpredictable ways. We conclude that the normally held assumptions of successful linear and incremental adaptation to new institutional patterns logics out by ERP systems do not hold.
Enhanced thermoelectric performance by the combination of alloying and doping in TiCoSb-based half-Heusler compounds
Authors: Qiu Pengfei , Huang Xiangyang , Chen Xihong , Chen Lidong
Published: November 2009

TiCoSb-based half-Heusler compounds have been prepared and their thermoelectric properties are studied. By isoelectronic alloying on the Ti site with Zr, although both the thermal conductivity and electrical conductivity are suppressed, the Seebeck coefficient is improved remarkably with a highest value of −420 μV/K for Ti0.5Zr0.5CoSb at 600 K, which provides a larger space to optimize the thermoelectric performance. To further improve the performance of the TiCoSb-based isoelectronic alloy, doping Ni on the Co site was explored. It is found that small amount of Ni doping results in a great increase in the electrical conductivity, still with a relative large Seebeck coefficient. Ti0.6Hf0.4Co0.87Ni0.13Sb sample exhibits a peak power factor of 23.4μW∕cmK2, which is the highest value for n-type TiCoSb-based half-Heusler compounds reported so far. As a result, a maximum dimensionless figure of merit of 0.70 has been achieved at 900 K for Ti0.6Hf0.4Co0.87Ni0.13Sb.
Label-free diagnosis of human hepatocellular carcinoma by multiphoton autofluorescence microscopy
Authors: Sun Tzu-Lin , Liu Yuan , Sung Ming-Chin , Chen Hsiao-Ching , Yang Chun-Hui , Hovhannisyan Vladimir , Lin Wei-Chou , Chen Wei-Liang , Chiou Ling-Ling , Huang Guan-Tarn , Kim Ki Hean , So Peter T. C. , Lee Hsuan-Shu , Dong Chen-Yuan
Published: November 2009

Conventional diagnosis for hepatocellular carcinoma (HCC) is time consuming in sample preparation and deficient in quantitative examination. In this work, we developed multiphoton autofluorescence (MAF) microscopy as an effective and efficient tool in HCC diagnosis with qualitative imaging and quantitative measurement. We found that MAF imaging effectively identifies cellular architecture in the liver specimens. Our results also demonstrate the capability of using tissue quantitative parameters of multiphoton autofluorescence intensity ratio, the nuclear number density, and nuclear-cytoplasmic ratio for tumor discrimination. This approach has the potential in clinical diagnosis of HCC and the in vivo investigation of liver tumor development in animal models.
Spin-orbit effects on the photophysical properties of Ru(bpy)32+
Authors: Heully Jean-Louis , Alary Fabienne , Boggio-Pasqua Martial
Published: November 2009

We present in this article a detailed study of the photophysics of the Ru(bpy)32+ complex based on a formalism using density functional theory and an a posteriori treatment of the spin-orbit coupling. The absorption and emission spectra were computed and a very good agreement was obtained with the available experimental data. This work also reveals for the first time that the triplet metal-centered (MC) dd state cannot deactivate radiatively and corresponds to a transient structure for the nonradiative de-excitation of the triplet metal-to-ligand charge transfer (MLCT) state. Thus, a competition takes place between the luminescence of the MLCT state and nonradiative decay back to the ground state via population of the MC state. This radiationless return to the ground state occurs via a deactivation funnel which has been characterized for the first time by optimizing the minimum energy crossing point between the triplet MC and singlet ground state potential energy surfaces. Its low-lying energy position relative to the energy necessary to access the MC minimum suggests that this funnel will be readily accessible.
Influence of nanoparticle height on plasmonic resonance wavelength and electromagnetic field enhancement in two-dimensional arrays
Authors: Henson John , DiMaria Jeff , Paiella Roberto
Published: November 2009

A detailed experimental and theoretical study of the plasmonic properties of silver nanoparticle arrays as a function of nanoparticle height is presented. Specifically, several square periodic arrays have been fabricated by electron beam lithography and characterized via transmission spectroscopy measurements. The same arrays have also been numerically investigated via finite-difference time-domain calculations of their scattering and absorption cross sections and steady-state field intensity distributions. The results of this study show that the collective plasmonic resonances of these arrays can be effectively blueshifted by increasing the nanoparticle height, while at the same time maximizing the average field enhancement in the substrate and maintaining small absorption losses. This approach can therefore be used to extend the spectral reach of lithographically defined metallic nanoparticle arrays for practical applications such as light-emission efficiency enhancement.
Upper critical field and Raman spectra of MgB2 thin films irradiated with low energy oxygen ion
Authors: Wang J. , Zhuang C. G. , Li J. , Wang Y. Z. , Feng Q. R. , Zheng D. N.
Published: November 2009

The structure, upper critical field, and Raman spectrum of epitaxial MgB2 thin films irradiated by 300 keV O2+ ions have been investigated. Lattice parameter c expands after irradiation. There is a significant increase in upper critical field in the moderately irradiated films, while the critical temperature is reduced slightly. The values of critical field at zero temperature exhibit a maximum for samples with a moderate irradiation level for the applied magnetic field both perpendicular and parallel to the film surface. The temperature dependence of the anisotropy parameter, which is defined as the ratio of the upper critical field with the field parallel to the film surface and perpendicular to the film surface, reveals that oxygen ion irradiation mainly affects the σ band at a low irradiation level. With increasing irradiation level, π band scattering is strongly enhanced, and finally both bands are in the dirty limit. A broad peak centered around 570 cm−1 is observed in the Raman spectrum of the unirradiated films, and the peak position has a visible redshift in the irradiated samples. In particular, high-frequency spectral structures appear and become dominant, while the E2g broad band diminishes gradually with increasing irradiation fluence. The results are discussed by considering the disorder-induced change in carrier scattering within and between the σ and π bands and a violation of the Raman selection rules due to oxygen ion irradiation.
Angular dependence of magnetic properties in Ni nanowire arrays
Authors: Lavín R. , Denardin J. C. , Escrig J. , Altbir D. , Cortés A. , Gómez H.
Published: November 2009

The angular dependence of the remanence and coercivity of Ni nanowire arrays produced inside the pores of anodic alumina membranes has been studied. By comparing our analytical calculations with our measurements, we conclude that the magnetization reversal in this array is driven by means of the nucleation and propagation of a transverse wall. A simple model based on an adapted Stoner–Wohlfarth model is used to explain the angular dependence of the coercivity.
Comment on “Influence of atomic force microscope cantilever tilt and induced torque on force measurements” [J. Appl. Phys. 103, 064513 (2008)]
Authors: Wang Fei
Published: November 2009

In a recent article, Edwards et al. [J. Appl. Phys. 103, 064513 (2008)] examined the effect of cantilever tilt and induced torque on the effective normal spring constant for both sharp tips and spherical probes, and in contrast to previous studies, they found that induced tip torque can act to either enhance or reduce the effective normal spring constant of the cantilever, which is of great value for force measurement in atomic force microscopy. However, their work is technically limited in application by their nonparallel-force assumption. In this comment, we improve their work to be more applicable by developing a more practical model without the nonparallel-force assumption.