bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Performance of Silicon Micro Heat-Sinks With Electrokinetically-Driven Flows
Authors: Morini Gian Luca , Lorenzini Marco , Salvigni Sandro , Spiga Marco
Published: May 2009

A heat sink consisting of microchannels of rectangular or trapezoidal cross-section through which a polar fluid is circulated by means of an electro-osmotic pump was studied numerically. The equivalent pressure head–volume flow rate curve was determined for both geometries and the influence of the aspect ratio was investigated. The dimensionless temperature profile was determined keeping also the effect of Joule heating into account. The cross-sectional Nusselt number was calculated for the above conditions and was found to be strongly influenced by the ratio of Joule heating to convective heat flux, Mz. The dependence of the Nusselt number on the dimensionless electro-osmotic diameter (kDh) was also investigated for the two geometries and for increasing values of Mz, and a comparison with the values obtained analytically for slug flow under the same conditions was made. The value of the Nusselt number as a function of the aspect ratio was also calculated for increasing values of Mz. The numerical data presented in this paper can be useful to optimize the thermal performance of silicon micro heat-sinks.
Use of a line‐pair resolution phantom for comprehensive quality assurance of electronic portal imaging devices based on fundamental imaging metrics
Authors: Gopal Arun , Samant Sanjiv S.
Published: May 2009

Image guided radiation therapy solutions based on megavoltage computed tomography (MVCT) involve the extension of electronic portal imaging devices (EPIDs) from their traditional role of weekly localization imaging and planar dose mapping to volumetric imaging for 3D setup and dose verification. To sustain the potential advantages of MVCT, EPIDs are required to provide improved levels of portal image quality. Therefore, it is vital that the performance of EPIDs in clinical use is maintained at an optimal level through regular and rigorous quality assurance (QA). Traditionally, portal imaging QA has been carried out by imaging calibrated line‐pair and contrast resolution phantoms and obtaining arbitrarily defined QA indices that are usually dependent on imaging conditions and merely indicate relative trends in imaging performance. They are not adequately sensitive to all aspects of image quality unlike fundamental imaging metrics such as the modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) that are widely used to characterize detector performance in radiographic imaging and would be ideal for QA purposes. However, due to the difficulty of performing conventional MTF measurements, they have not been used for routine clinical QA. The authors present a simple and quick QA methodology based on obtaining the MTF, NPS, and DQE of a megavoltage imager by imaging standard open fields and a bar‐pattern QA phantom containing 2 mm thick tungsten line‐pair bar resolution targets. Our bar‐pattern based MTF measurement features a novel zero‐frequency normalization scheme that eliminates normalization errors typically associated with traditional bar‐pattern measurements at megavoltage x‐ray energies. The bar‐pattern QA phantom and open‐field images are used in conjunction with an automated image analysis algorithm that quickly computes the MTF, NPS, and DQE of an EPID system. Our approach combines the fundamental advantages of linear systems metrics such as robustness, sensitivity across the full spatial frequency range of interest, and normalization to imaging conditions (magnification, system gain settings, and exposure), with the simplicity, ease, and speed of traditional phantom imaging. The algorithm was analyzed for accuracy and sensitivity by comparing with a commercial portal imaging QA method (PIPSPRO™, Standard Imaging, Middleton, WI) on both first‐generation lens‐coupled and modern flat‐panel based clinical EPID systems. The bar‐pattern based QA measurements were found to be far more sensitive to even small levels of degradation in spatial resolution and noise. The bar‐pattern based QA methodology offers a comprehensive image quality assessment tool suitable for both commissioning and routine EPID QA.
Measurement of MRI scanner performance with the ADNI phantom
Authors: Gunter Jeffrey L. , Bernstein Matt A. , Borowski Brett J. , Ward Chadwick P. , Britson Paula J. , Felmlee Joel P. , Schuff Norbert , Weiner Michael , Jack Clifford R.
Published: May 2009

The objectives of this study are as follows: to describe practical implementation challenges of multisite, multivendor quantitative studies; to describe the MRI phantom and analysis software used in the Alzheimer's Disease Neuroimaging Initiative (ADNI) study, illustrate the utility of the system for measuring scanner performance, the ability to assess gradient field nonlinearity corrections: and to recover human brain images without geometric scaling errors in multisite studies. ADNI is a large multicenter study with each center having its own copy of the phantom. The design of the phantom and analysis software are presented as results from predistribution systematics studies and results from field experience with the phantom at 58 enrolling ADNI sites over a period. The estimated coefficients of variation intrinsic to measurements of geometry in a single phantom are in the range of 3–5 parts in . Phantom measurements accurately detect linear and nonlinear scaling in images. Gradient unwarping methods are readily assessed by phantom nonlinearity measurements. Phantom‐based scaling correction reduces observed geometric drift in human images by one‐third or more. Repair or replacement of phantoms between scans, however, is a confounding factor. The ADNI phantom can be used to assess both scanner performance and the validity of postprocessing image corrections in order to reduce systematic errors in human images. Reduced measurement errors should decrease measurement bias and increase statistical power for measurements of rates of change in the brain structure in AD treatment trials. Perhaps the greatest practical value of incorporating ADNI phantom measurements in a multisite study is to identify scanner errors through central monitoring. This approach has resulted in identification of system errors including sites misidentification of their own gradient hardware and the disabling of autoshim, and a miscalibrated laser alignment light. If undetected, these errors would have contributed to imprecision in quantitative metrics at over 25% of all enrolling ADNI sites.
A method to generate equivalent energy spectra and filtration models based on measurement for multidetector CT Monte Carlo dosimetry simulations
Authors: Turner Adam C. , Zhang Di , Kim Hyun J. , DeMarco John J. , Cagnon Chris H. , Angel Erin , Cody Dianna D. , Stevens Donna M. , Primak Andrew N. , McCollough Cynthia H. , McNitt‐Gray Michael F.
Published: May 2009

The purpose of this study was to present a method for generating x‐ray source models for performing Monte Carlo (MC) radiation dosimetry simulations of multidetector row CT (MDCT) scanners. These so‐called “equivalent” source models consist of an energy spectrum and filtration description that are generated based wholly on the measured values and can be used in place of proprietary manufacturer's data for scanner‐specific MDCT MC simulations. Required measurements include the half value layers ( and ) and the bowtie profile (exposure values across the fan beam) for the MDCT scanner of interest. Using these measured values, a method was described (a) to numerically construct a spectrum with the calculated HVLs approximately equal to those measured (equivalent spectrum) and then (b) to determine a filtration scheme (equivalent filter) that attenuates the equivalent spectrum in a similar fashion as the actual filtration attenuates the actual x‐ray beam, as measured by the bowtie profile measurements. Using this method, two types of equivalent source models were generated: One using a spectrum based on both and measurements and its corresponding filtration scheme and the second consisting of a spectrum based only on the measured and its corresponding filtration scheme. Finally, a third type of source model was built based on the spectrum and filtration data provided by the scanner's manufacturer. MC simulations using each of these three source model types were evaluated by comparing the accuracy of multiple CT dose index (CTDI) simulations to measured CTDI values for 64‐slice scanners from the four major MDCT manufacturers. Comprehensive evaluations were carried out for each scanner using each kVp and bowtie filter combination available. CTDI experiments were performed for both head ( in diameter) and body ( in diameter) CTDI phantoms using both central and peripheral measurement positions. Both equivalent source model types result in simulations with an average root mean square (RMS) error between the measured and simulated values of approximately 5% across all scanner and bowtie filter combinations, all kVps, both phantom sizes, and both measurement positions, while data provided from the manufacturers gave an average RMS error of approximately 12% pooled across all conditions. While there was no statistically significant difference between the two types of equivalent source models, both of these model types were shown to be statistically significantly
dfferent from the source model based on manufacturer's data. These results demonstrate that an equivalent source model based only on measured values can be used in place of manufacturer's data for Monte Carlo simulations for MDCT dosimetry.
Fast convolution‐superposition dose calculation on graphics hardware
Authors: Hissoiny Sami , Ozell Benoît , Després Philippe
Published: May 2009

The numerical calculation of dose is central to treatment planning in radiation therapy and is at the core of optimization strategies for modern delivery techniques. In a clinical environment, dose calculation algorithms are required to be accurate and fast. The accuracy is typically achieved through the integration of patient‐specific data and extensive beam modeling, which generally results in slower algorithms. In order to alleviate execution speed problems, the authors have implemented a modern dose calculation algorithm on a massively parallel hardware architecture. More specifically, they have implemented a convolution‐superposition photon beam dose calculation algorithm on a commodity graphics processing unit (GPU). They have investigated a simple porting scenario as well as slightly more complex GPU optimization strategies. They have achieved speed improvement factors ranging from 10 to 20 times with GPU implementations compared to central processing unit (CPU) implementations, with higher values corresponding to larger kernel and calculation grid sizes. In all cases, they preserved the numerical accuracy of the GPU calculations with respect to the CPU calculations. These results show that streaming architectures such as GPUs can significantly accelerate dose calculation algorithms and let envision benefits for numerically intensive processes such as optimizing strategies, in particular, for complex delivery techniques such as IMRT and arc therapy.
On the characterization and uncertainty analysis of radiochromic film dosimetry
Authors: Bouchard Hugo , Lacroix Frédéric , Beaudoin Gilles , Carrier Jean‐François , Kawrakow Iwan
Published: May 2009

Radiochromic film is a dosimeter of choice in applications requiring high spatial resolution, two dimensional measurements, or minimum perturbation of the beam fluence. Since the measurement uncertainty in Gafchromic film dosimetry is thought to be significant compared to that of ionization chambers, a rigorous method to evaluate measurement uncertainties is desired. This article provides a method that takes into account the correlation between fit parameters as well as single dose values in order to obtain accurate uncertainties in absolute and relative measurements. A complete portrait of all sources of uncertainty in Gafchromic film dosimetry is given. The parametrization of variance as a function of the number of averaged pixels is obtained in order to accurately predict the uncertainty as a function of the size of the region of interest. The choice of functional form for the sensitometric curve is based on four criteria and a convergence of global net optical density uncertainty to 0.0013 is demonstrated. A minimum number of 12 points is recommended to characterize the sensitometric curve to a sufficient precision on the uncertainty estimation. Uncertainty levels of 0.9% on absolute dose measurements and 0.45% on relative measurements are achieved using a 12‐point calibration curve with 220 cGy and repeating measurements five times. Uncertainties of 0.8% and 0.4% are achievable when using 35 points during film characterization. Ignoring covariance terms is shown to lead to errors in the estimation of uncertainty.
Heuristic optimization of the scanning path of particle therapy beams
Authors: Pardo J. , Donetti M. , Bourhaleb F. , Ansarinejad A. , Attili A. , Cirio R. , Garella M. A. , Giordanengo S. , Givehchi N. , La Rosa A. , Marchetto F. , Monaco V. , Pecka A. , Peroni C. , Russo G. , Sacchi R.
Published: May 2009

Quasidiscrete scanning is a delivery strategy for proton and ion beam therapy in which the beam is turned off when a slice is finished and a new energy must be set but not during the scanning between consecutive spots. Different scanning paths lead to different dose distributions due to the contribution of the unintended transit dose between spots. In this work an algorithm to optimize the scanning path for quasidiscrete scanned beams is presented. The classical simulated annealing algorithm is used. It is a heuristic algorithm frequently used in combinatorial optimization problems, which allows us to obtain nearly optimal solutions in acceptable running times. A study focused on the best choice of operational parameters on which the algorithm performance depends is presented. The convergence properties of the algorithm have been further improved by using the next‐neighbor algorithm to generate the starting paths. Scanning paths for two clinical treatments have been optimized. The optimized paths are found to be shorter than the back‐and‐forth, top‐to‐bottom (zigzag) paths generally provided by the treatment planning systems. The gamma method has been applied to quantify the improvement achieved on the dose distribution. Results show a reduction of the transit dose when the optimized paths are used. The benefit is clear especially when the fluence per spot is low, as in the case of repainting. The minimization of the transit dose can potentially allow the use of higher beam intensities, thus decreasing the treatment time. The algorithm implemented for this work can optimize efficiently the scanning path of quasidiscrete scanned particle beams. Optimized scanning paths decrease the transit dose and lead to better dose distributions.
CADx of mammographic masses and clustered microcalcifications: A review
Authors: Elter Matthias , Horsch Alexander
Published: May 2009

Breast cancer is the most common type of cancer among women in the western world. While mammography is regarded as the most effective tool for the detection and diagnosis of breast cancer, the interpretation of mammograms is a difficult and error‐prone task. Hence, computer aids have been developed that assist the radiologist in the interpretation of mammograms. Computer‐aided detection (CADe) systems address the problem that radiologists often miss signs of cancers that are retrospectively visible in mammograms. Furthermore, computer‐aided diagnosis (CADx) systems have been proposed that assist the radiologist in the classification of mammographic lesions as benign or malignant. While a broad variety of approaches to both CADe and CADx systems have been published in the past two decades, an extensive survey of the state of the art is only available for CADe approaches. Therefore, a comprehensive review of the state of the art of CADx approaches is presented in this work. Besides providing a summary, the goals for this article are to identify relations, contradictions, and gaps in literature, and to suggest directions for future research. Because of the vast amount of publications on the topic, this survey is restricted to the two most important types of mammographic lesions: masses and clustered microcalcifications. Furthermore, it focuses on articles published in international journals.
A novel method to evaluate gamma camera rotational uniformity and sensitivity variation
Authors: Kappadath S. Cheenu , Erwin William D. , Wendt Richard E.
Published: May 2009

An alternative to the conventional method of performing the AAPM Report 52 rotational uniformity and sensitivity test has been developed. In contrast to the conventional method in which a Co‐57 sheet source is fastened to the collimator, this new point‐source method acquires the images intrinsically using a Tc‐99m point source placed near the isocenter of gantry rotation. As with the conventional method, the point‐source method acquires count flood images at four distinct gantry positions to calculate the maximum sensitivity variation (MSV)—a quantitative metric of rotational uniformity and sensitivity variation. The point‐source method incorporates corrections for the decay of Tc‐99m between acquisitions, the curvature in the image intensity due to variation in photon flux across the detector from a near‐field source, and the source‐to‐detector distance variations between views. The raw point‐source images were fitted with an analytic function in order to compute curvature‐ and distance‐corrected images prior to analysis. Five independent MSV measurements were performed using both conventional and point‐source methods on a single detector of a dual‐headed SPECT system to estimate the precision of each method. The precision of the point‐source method was further investigated by performing ten independent measurements of MSV on six different detectors. Correlation between the MSV calculated by the two methods was investigated by performing the test on nine different detectors using both methods. Different levels of sensitivity variations were also simulated on four detectors to generate 40 additional paired points for correlation analysis. The effect of the total image counts on the MSV estimated with the new method was evaluated by acquiring image sequences with , , and count images. The MSV calculated using the conventional and point‐source methods exhibited a high degree of correlation and consistency with equivalence. The precision of the point‐source method (0.145%) is lower than the conventional method (0.04%) but sufficient to test MSV. No statistically significant dependence of MSV with the point‐source method on the total image counts over a range of counts was observed. Curvature correction of the images prior to the generation of difference images renders images more conducive to qualitative inspection for structured, nonrandom patterns. The advantages of the new methodology are that multiple detectors of a gamma camera can be evaluated simultaneously which substantially reduces the time required for MSV testing and the reduced risk of accidental damage to the collimators and patient proximity detection system from having to mount a sheet source on each of the detectors.
Scatter correction for cone‐beam CT in radiation therapy
Authors: Zhu Lei , Xie Yaoqin , Wang Jing , Xing Lei
Published: May 2009

Cone‐beam CT (CBCT) is being increasingly used in modern radiation therapy for patient setup and adaptive replanning. However, due to the large volume of x‐ray illumination, scatter becomes a rather serious problem and is considered as one of the fundamental limitations of CBCT image quality. Many scatter correction algorithms have been proposed in literature, while a standard practical solution still remains elusive. In radiation therapy, the same patient is scanned repetitively during a course of treatment, a natural question to ask is whether one can obtain the scatter distribution on the first day of treatment and then use the data for scatter correction in the subsequent scans on different days. To realize this scatter removal scheme, two technical pieces must be in place: (i) A strategy to obtain the scatter distribution in on‐board CBCT imaging and (ii) a method to spatially match a prior scatter distribution with the on‐treatment CBCT projection data for scatter subtraction. In this work, simple solutions to the two problems are provided. A partially blocked CBCT is used to extract the scatter distribution. The x‐ray beam blocker has a strip pattern, such that partial volume can still be accurately reconstructed and the whole‐field scatter distribution can be estimated from the detected signals in the shadow regions using interpolation/extrapolation. In the subsequent scans, the patient transformation is determined using a rigid registration of the conventional CBCT and the prior partial CBCT. From the derived patient transformation, the measured scatter is then modified to adapt the new on‐treatment patient geometry for scatter correction. The proposed method is evaluated using physical experiments on a clinical CBCT system. On the Catphan©600 phantom, the errors in Hounsfield unit (HU) in the selected regions of interest are reduced from about 350 to below ; on an anthropomorphic phantom, the error is reduced from 15.7% to 5.4%. The proposed method is attractive in applications where a high CBCT image quality is critical, for example, dose calculation in adaptive radiation therapy.
Inference of the optimal pretarget electron beam parameters in a Monte Carlo virtual linac model through simulated annealing
Authors: Bush Karl , Zavgorodni Sergei , Beckham Wayne
Published: May 2009

The purpose of this study was to develop an efficient method to determine the optimal intensity distribution of the pretarget electron beam in a Monte Carlo (MC) accelerator model able to most accurately reproduce a set of measured photon field profiles for a given accelerator geometry and nominal photon beam energy. The method has the ability to reduce the number of simulations required to commission a MC accelerator model and has achieved better agreement with measurement than other methods described in literature. The method begins from a cylindrically symmetric pretarget electron beam (radius of 0.5 cm) of uniform intensity. This beam is subdivided into annular regions of fluence for which each region is individually transported through the accelerator head and into a water phantom. A simulated annealing search is then performed to determine the optimal combination of weights of the annular fluences that provide a best match between the measured dose distributions and the weighted sum of annular dose distributions for particular pretarget electron energy. When restricted to Gaussian intensity distributions, the optimization determined an optimal for 18.0 MeV electrons, with a on lateral profiles. When allowed to deviate from Gaussian intensities a further reduction in RMSE was achieved. For our Clinac 21 EX accelerator MC model (based on the 1996 Varian Oncology Systems, Monte Carlo Project package), the optimal unrestricted intensity distribution was found to be a Gaussian‐like solution (18.0 MeV, , profile, and ) with the presence of an extra focal halo contribution on the order of 10% of the maximum Gaussian intensity. Using the optimally derived intensity, and profiles were found to be in agreement with measurement with a maximum . The optimized Gaussian and unrestricted values of the electron beam FWHM were both within the range of those inferred by focal spot image measurements performed by Jaffray et al. [“X‐ray sources of medical linear accelerators: Focal and extra‐focal radiation,” Med. Phys. 20, 1417–1427 (1993)]. The inference of an extra focal pretarget electron component may be an indicator of a deficiency in the MC model and needs further investigation.
In vivo functional chronic imaging of a small animal model using optical‐resolution photoacoustic microscopy
Authors: Hu Song , Maslov Konstantin , Wang Lihong V.
Published: May 2009

Optical‐resolution photoacoustic microscopy (OR‐PAM) has been validated as a valuable tool for label‐free volumetric microvascular imaging. More importantly, the advantages of noninvasiveness and measurement consistency suggest the use of OR‐PAM for chronic imaging of intact microcirculation. Here, such chronic imaging is demonstrated for the first time by monitoring the healing process of laser‐induced microvascular lesions in a small animal model in vivo. The central part of a 1 mm by 1 mm region in a nude mouse ear was treated under a continuous‐wave laser to create a microvascular lesion for chronic study. The region of interest was imaged before the laser treatment, immediately after the treatment, and throughout the healing process using both the authors’ OR‐PAM system and a commercial transmission‐mode optical microscope. Three‐dimensional microvascular morphology and blood oxygenation information were imaged simultaneously at capillary‐level resolution. Transmission‐mode optical microscopic images were acquired for comparison. OR‐PAM has potential important applications in microcirculatory physiology or pathophysiology, tumor angiogenesis, laser microsurgery, and neuroscience.
Ventral Tegmental Area BDNF Induces an Opiate-Dependent–Like Reward State in Naïve Rats
Authors: Vargas-Perez Hector , Ting-A-Kee Ryan , Walton Christine H. , Hansen D. Micah , Razavi Rozita , Clarke Laura , Bufalino Mary Rose , Allison David W. , Steffensen Scott C. , van der Kooy Derek
Published: May 2009

BDNF and Drug Dependence

Brain-derived neurotrophic factor (BDNF) is a growth factor involved in neuronal plasticity that is expressed after chronic administration of drugs of abuse and may play a crucial role in chronic opiate effects.

Vargas-Perez
et al.

(p.
1732
, published online 28 May) found that BDNF was directly involved in the switching mechanism in the ventral tegmental area, from an opiate-naïve, dopamine-independent drug reward substrate to an opiate-dependent, dopamine-dependent motivational substrate. In the ventral tegmental area, BDNF changed the action of GABA-A receptors from inhibitory to excitatory. This change led to behavioral changes that defined a neurobiological boundary between the acute phase of drug-taking and addiction.
To protect or to publish: confidentiality and the fate of the mentally ill victims of Nazi euthanasia
Authors: Strous R D
Published: May 2009

In Nazi Germany, approximately 200 000 mentally ill people were murdered under the guise of euthanasia. Relatively little is known regarding the fate of the Jewish mentally ill patients targeted in this process, long before the Holocaust officially began. For the Nazis, Jewish mentally ill patients were doubly cursed since they embodied both “precarious genes” and “racial toxin”. To preserve the memory of the victims, Yad Vashem, the leading institution dedicated to documentation of the Holocaust, actively collects information and documents the fate of victims in an open online database. Recently, a list of approximately 1200 names of Jewish mentally ill euthanasia victims has been compiled from hospital archives. Their fate remains unknown to surviving family members. Given the duty to preserve medical confidentiality, can this list be publicised for public interest and for notifying families—publicising names and death circumstances, including where “killed” would immediately indicate that the person had had a mental illness? Does the right to medical confidentiality lapse upon death? Is time elapsed since death a factor? Can opposing obligations of preserving victims’ memory over-ride medical confidentiality? What if a family member objects to a grandparent’s name being exposed on the list of mentally ill patients? This article considers these issues as well as the “rational” and “non-rational” factors in ethical decisional making surrounding this unique dilemma. Several possible solutions are proposed including preserving the list in a locked database for access by families and researchers, publicising in the media that such a list exists, publishing the information online without any identifiers and submitting the information to historians, allowing them to process the data as they see fit.
The development of “medical futility”: towards a procedural approach based on the role of the medical profession
Authors: Moratti S
Published: May 2009

Over the past 50 years, technical advances have taken place in medicine that have greatly increased the possibilities of life-prolonging intervention. The increased possibilities of intervening have brought along new ethical questions. Not everything that is technically possible is appropriate in a specific case: not everything thatcouldbe doneshouldbe done. In the 1980s, a new term was coined to indicate a class of inappropriate interventions: “medically futile treatment”. A debate followed, with contributions from the USA and several western European countries. A similar debate later took place in Mediterranean countries, although with a different terminology. The purpose of this article is to provide an up-to-date and systematic analysis of the concept of futility, and to draw some conclusions on its operationalisation in medical practice. While the concept of “medical futility” in theory applies to all kinds of medical intervention that might be performed without being medically indicated—things such as certain medical screenings and cosmetic surgery—in practice the literature on “futility” deals only with life-saving and life-sustaining medical interventions. This article deals with this more limited application of the concept of “futility”.
Science journal editors’ views on publication ethics: results of an international survey
Authors: Wager E , Fiack S , Graf C , Robinson A , Rowlands I
Published: May 2009

Background:

Breaches of publication ethics such as plagiarism, data fabrication and redundant publication are recognised as forms of research misconduct that can undermine the scientific literature. We surveyed journal editors to determine their views about a range of publication ethics issues.

Methods:

Questionnaire sent to 524 editors-in-chief of Wiley-Blackwell science journals asking about the severity and frequency of 16 ethical issues at their journals, their confidence in handling such issues, and their awareness and use of guidelines.

Results:

Responses were obtained from 231 editors (44%), of whom 48% edited healthcare journals. The general level of concern about the 16 issues was low, with mean severity scores of <1 (on a scale of 0–3) for all but one. The issue of greatest concern (mean score 1.19) was redundant publication. Most editors felt confident in handling the issues, with <15% feeling “not at all confident” for all but one of the issues (gift authorship, 22% not confident). Most editors believed such problems occurred less than once a year and >20% of the editors stated that 12 of the 16 items never occurred at their journal. However, 13%–47% did not know the frequency of the problems. Awareness and use of guidelines was generally low. Most editors were unaware of all except other journals’ instructions.

Conclusions:

Most editors of science journals seem not very concerned about publication ethics and believe that misconduct occurs only rarely in their journals. Many editors are unfamiliar with available guidelines but would welcome more guidance or training.
An ethical and social examination of dementia as depicted in Japanese film
Authors: Asai A , Sato Y , Fukuyama M
Published: May 2009

The ageing population means that dementia is a serious social problem in Japan. Attitudes toward ageing in Japan are increasingly negative, and views of life and death among older people vary. Numerous ethical problems exist in the medical treatment of dementia. Amidst such conditions, it is important and beneficial to examine films that depict demented patients and to consider the issues raised by these films. Through film we see many aspects of a country and its times: culture and ideology, morality and religion, medical treatments, views on life and death, social conditions and what issues are viewed as problems. The best films both entertain audiences and provide viewers with opportunities to think about social problems. In the past 30 years, 10 films about dementia had been made in Japan and two of these—The Twilight Years(Kôkotsu no hito) andMemories of Tomorrow(Ashita no kioku) are the main focus of this paper. In our analysis we consider three points: how the patients are informed of their disease, the characters’ wishes for death, and terminal medical care.
The death of Hector: pity in Homer, empathy in medical education
Authors: Marshall R , Bleakley A
Published: May 2009

Empathy is thought a desirable quality in doctors as a key component of communication skills and professionalism. It is therefore thought desirable to teach it to medical students. Yet empathy is a quality whose essence is difficult to capture but easy to enact. We problematise empathy in an era where empathy has been literalised and instrumentalised, including its measurement. Even if we could agree a universally acceptable definition of empathy, engendering it in the student requires a more subtle approach than seems the case currently.

We therefore examine this modern concept and compare it with others such as pity and compassion, using the medium of Homer’sIliad. Two famous scenes from theIliadelicit pity in the characters and the audience. Pity and compassion are, however, given a complexity within the narrative that often seems lacking in modern ways of conceptualising and teaching empathy.
Nitrate and phosphate removal in sulphur-coral stone autotrophic denitrification packed-bed reactorsA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Ruan Yun-Jie , Luo Guo-Zhi , Tan Hong-Xin , Che Xuan , Jiang Yan , Sun Da-Chuan
Published: May 2009

The removal effect on nitrate and phosphate of a sulphur-based autotrophic denitrifying bioreactor in composite packing of sulphur with coral stone were investigated on a pilot scale. The results showed that the optimal influent loading rate of the bioreactor (the ratio of sulphur volume to coral stone volume was 1:1) was in the range of 0.080–0.244 kg NO3–-N/(m3·d) when the water temperature was 29 ± 1 °C. In this range, the removal efficiency of nitrates was higher than 95% and no nitrite accumulation occurred in the effluent. The maximum nitrate volumetric removal rate of 0.594 kg NO3–-N / (m3·d) was achieved at an influent loading rate of 0.716 kg NO3–-N/(m3·d) with obvious nitrite accumulation in the effluent. Along with the autotrophic denitrifying reaction, an influent loading rate between 0.070–0.210 kg PO43–-P/ (m3·d) achieved the removal efficiency and volumetric removal rate of phosphates were 50.5%–89.2% and 0.045–0.179 kg PO43–-P/(m3·d), respectively. The phosphates related to the resistance ability of the bioreactor (the ratio of sulphur volume to coral stone volume was 1:1) was stronger than that of bioreactors (the ratio of sulphur volume to coral stone volume was 1:2 and 1:4).
Simulation of odour dispersion downwind from natural windbreaks using the computational fluid dynamics standard k-ε modelA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Lin Xing Jun , Barrington Suzelle , Gong Guangcai , Choinière Denis
Published: May 2009

If natural windbreaks create air turbulence and can help disperse odours from livestock operations, their dispersion effect has not been extensively researched. This paper introduces a model simulating odour dispersion downwind from natural windbreaks. The standard k-ε model of the FLUENT software was used to incorporate the effect of climatic conditions and windbreak structure. The model was calibrated for wind velocity recovery, odour concentration (OC) from field observations and inertial resistance. Once calibrated, the model accurately reproduced the odour plume developing downwind from the windbreak. The correlation between OC for 11 field trials and that simulated were statistically significant (P < 0.01), indicating that the model was accurate. The model demonstrated that a windbreak did alter the magnitude and direction of the wind velocity, thus creating a pressure jump across its width. This pressure jump produces a strong downwind turbulence forming a mixing layer capable of enhancing odour dispersion.
LANDAU-ZENER TRANSITIONS IN THE PRESENCE OF SPIN ENVIRONMENT
Authors: WAN ANDY T. S. , AMIN M. H. S. , WANG SHANNON X.
Published: May 2009

We study the effect of an environment consisting of noninteracting two level systems on Landau-Zener transitions with an interest on the performance of an adiabatic quantum computer. We show that if the environment is initially at zero temperature, it does not affect the transition probability. An excited environment, however, will always increase the probability of making a transition out of the ground state. For the case of equal intermediate gaps, we find an analytical upper bound for the transition probability in the limit of large number of environmental spins. We show that such an environment will only suppress the probability of success for adiabatic quantum computation by at most a factor close to 1/2.
INFORMATION ENERGY AS AN ELECTRON CORRELATION MEASURE IN ATOMIC AND MOLECULAR SYSTEMS
Authors: MOHAJERI AFSHAN , ALIPOUR MOJTABA
Published: May 2009

The information energy is proposed as a possible measure for electron correlation energy in atoms and molecules. For neutral atoms and their cations, we proposed an expression for correlation energy with explicit dependence on the information energy and atomic number. The obtained correlation energies have been used to compute the first ionization potentials of the ground state of the main group elements from hydrogen through krypton.

It is shown that the information energy of a molecule can be well-estimated by use of the information energies of its constituent atoms. On the basis of the molecular information energy and number of electrons in the molecule, a simple model has been proposed for evaluation of molecular correlation energy.
DECOHERENCE-FREE QUANTUM MEMORY FOR PHOTONIC STATE USING ATOMIC ENSEMBLES
Authors: MEI FENG , YU YA-FEI , ZHANG ZHI-MING
Published: May 2009

Large scale quantum information processing requires stable and long-lived quantum memories. Here, using atom-photon entanglement, we propose an experimentally feasible scheme to realize decoherence-free quantum memory with atomic ensembles, and show one of its applications, remote transfer of unknown quantum state, based on laser manipulation of atomic ensembles, photonic state operation through optical elements, and single-photon detection with moderate efficiency. The scheme, with inherent fault-tolerance to the practical noise and imperfections, allows one to retrieve the information in the memory for further quantum information processing within the reach of current technology.
RICCI FLOW, QUANTUM MECHANICS AND GRAVITY
Authors: ISIDRO JOSÉ M. , SANTANDER J. L. G. , FERNÁNDEZ DE CÓRDOBA P.
Published: May 2009

It has been argued that, underlying any given quantum-mechanical model, there exists at least one deterministic system that reproduces, after prequantization, the given quantum dynamics. For a quantum mechanics with a complex d-dimensional Hilbert space, the Lie group SU(d) represents classical canonical transformations on the projective space ℂℙd-1 of quantum states. Let R stand for the Ricci flow of the manifold SU(d-1) down to one point, and let P denote the projection from the Hopf bundle onto its base ℂℙd-1. Then the underlying deterministic model we propose here is the Lie group SU(d), acted on by the operation PR. Finally we comment on some possible consequences that our model may have on a quantum theory of gravity.
Swim training suppresses tumor growth in mice
Authors: Almeida Pedro William M. , Gomes-Filho Ary , Ferreira Anderson J. , Rodrigues Carlos Eduardo M. , Dias-Peixoto Marco Fabrício , Russo Remo C. , Teixeira Mauro M. , Cassali Geovanni D. , Ferreira Enio , Santos Ivan C. , Garcia Alessandra M. C. , Silami-Garcia Emerson , Wisløff Ulrik , Pussieldi Guilherme A.
Published: May 2009

The present study was designed to determine the effects of physical training on the development of cancer induced by the injection of Ehrlich tumor cells in mice. Male Swiss mice were subjected to a swim training protocol (5 days/wk for 6 wk, 1 h at 50% of maximal capacity-trained groups) or remained sedentary in their cages (sedentary groups). The inoculation of Ehrlich tumor cells was performed at the end of the fourth week, and animals were killed after 6 wk of training. Heart and solid tumor weights were recorded, and tumor volumes were calculated. Portions of the tumors were used for the evaluation of macrophages and neutrophil accumulation or fixed in neutral 10% buffered formalin for histological analysis. The tumor volume and weight were, respectively, ∼270% and 280% greater in sedentary mice than in trained mice. Macrophage infiltration in the tumor tissue was significantly lower in trained mice (0.65 ± 0.16 vs. 1.78 ± 0.43 macrophages × 103in the sedentary group). Moreover, neutrophil accumulation in tumors was slightly reduced after exercise training, and the amount of tumor cells was reduced in trained mice. Exercise capacity was substantially increased in trained mice, as determined by a 440% increase in the exercise time at 50% of maximal capacity. In summary, swim training retarded the development of Ehrlich tumors in mice, accompanied by a reduction in macrophage infiltration and neutrophil accumulation. These findings provide conceptual support for clinical observations that controlled physical activities may be a therapeutically important approach to preventing cancer progression and may improve the outcome of cancer treatment.
Endoscopic Retrograde Cholangiopancreatography Using the Single Balloon Enteroscope Technique in Patients with Roux-en-Y Anastomosis
Authors: Neumann Helmut , Fry Lucía C. , Meyer Frank , Malfertheiner Peter , Mönkemüller Klaus
Published: May 2009

Background: Endoscopic retrograde cholangiopancreatography (ERCP) is technically challenging or impossible in patients with complex postsurgical anatomy. The aim of this cohort study was to assess the technical success of ERCP with the single balloon enteroscope (SBE) in patients with Roux-en-Y anastomosis. Patients: Patients with Roux-en-Y anastomosis presenting with cholestasis undergoing ERCP with the SBE technique in a tertiary university hospital. Diagnostic success was defined as successful duct cannulation or securing the diagnosis and therapeutic success was defined as the ability to successfully accomplish endoscopic therapy. Results: ERCP using the SBE was performed on 17 occasions in 13 patients (5 F, 8 M, mean age 66.5 years, range 25–77) with Roux-en-Y anastomosis. Indications for ERCP were biliary obstruction with common bile duct stones and/or cholangitis in all patients. The diagnostic success was 61.5% and the therapeutic success was 53.8%. Therapeutic interventions included dilation of common bile duct stenosis with a balloon (n = 4), biliary stent insertion (n = 2), removal of bile duct stones (n = 2), stent retrieval (n = 2), papillectomy (n = 1), and sphincterotomy (n = 1). No major complications occurred. Conclusions: ERCP using the SBE is feasible in patients with altered postsurgical anatomy presenting with biliary problems permitting diagnostic and therapeutic interventions.
Proteinase-Activated Receptor-2 Mediates the Expression of Integrin α5 and β1 in Helicobacter pylori-Infected Gastric Epithelial AGS Cells
Authors: Seo Ji Hye , Lim Joo Weon , Yoon Joo-Heon , Kim Hyeyoung
Published: May 2009

Background/Aim: Proteinase-activated receptor-2 (PAR2), which is activated by trypsin, is known to be associated with expression of adhesion molecule integrins. We previously demonstrated that Helicobacter pylori induced the expression of integrin α5 and β1 in human gastric epithelial cells. The present study aims to investigate whether H. pylori in a Korean isolate (HP99) induces the expression of PAR2, which mediates the expression of integrin α5 and β1 and thus cell adhesion to fibronectin in gastric epithelial AGS cells. Methods and Results: mRNA expressions of PAR2, trypsinogen 1 and 2, and integrin α5 and β1 were assessed by RT-PCR analysis while protein levels of PAR2, trypsin as well as integrin α5 and β1 were determined by Western blot analysis. The activity of trypsin in the medium was determined by fluorometric analysis. Cell adhesion assay was performed colorimetrically. H. pylori induced the expressions of PAR2 and integrin α5 and β1 of the cells. H. pylori increased mRNA expression of trypsinogen 1 and 2 as well as the level and activity of trypsin in the medium. H. pylori induced cell adhesion to fibronectin. H. pylori-induced expression of integrin α5 and β1 and adhesion of the cells to fibronectin were inhibited in the cells transfected with PAR2 antisense oligonucleotide or treated with a soybean trypsin inhibitor, anti-integrin α5 antibody or β1 antibody. Conclusion:H. pylori induces the expression of integrin α5 and β1 and adhesion of the cells to fibronectin through PAR2 which is induced and may be activated by trypsin in H. pylori-infected gastric epithelial cells. PAR2 may have an important role in gastric cell adhesion and possibly carcinogenesis associated with H. pylori.
Genetic Variation of CYP19 (Aromatase) Gene Influences Age at Onset of Alzheimer’s Disease in Women
Authors: Corbo Rosa Maria , Gambina Giuseppe , Ulizzi Laura , Moretto Giuseppe , Scacchi Renato
Published: May 2009

Background/Aims: There is evidence for a higher prevalence of Alzheimer’s disease (AD) in women, but whether this is due to their longer life expectancy or to biological gender-specific risk factors is unclear. One likely contributing factor is the reduced estrogen neuroprotective action following menopause. In this context, an AD risk gene could be CYP19, encoding aromatase, an enzyme involved in estrogen biosynthesis. Methods: We analyzed the role of 3 CYP19 single-nucleotide polymorphisms (rs12907866, rs17601241, rs4646) in AD development and their possible influence on quantitative traits reflecting disease severity (age at onset and cognitive decline) in 319 patients and 110 controls. Results: No association was observed between the CYP19 single-nucleotide polymorphisms and AD risk. Yet CYP19 genetic variation did seem to contribute to AD development in women as the rs4646 genotypes carrying the T allele were associated with an earlier onset age (p = 0.01) independently of a similar effect determined by the APOE e*4 allele (p = 0.005). Also, being present only in parous women (p = 0.01), the effect of rs4646 genotypes on onset age appeared to depend on past fertility. Conclusion: Together with gender-specific factors such as parity, genes controlling estrogen metabolism may play a relevant role in AD susceptibility in women.