bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Fungal Species Associated with Cladode Spot of Prickly Pear and Their Sensitivity to Chitosan
Authors: Flores‐Flores Rosalba , Velázquez‐del Valle Miguel G. , León‐Rodriguez Renato , Flores‐Moctezuma Hilda E. , Hernández‐Lauzardo Ana N.
Published: March 2013

México is the most important producer of prickly pear (Opuntia ficus‐indica) in the world. There are several fungal diseases that can have a negative impact on their yields. In this study, there was a widespread fungal richness on cladodes spot of prickly pears from México. A total of 41 fungi isolates were obtained from cladodes spot; 11 of them were morphologically different. According to the pathogenicity test, seven isolates caused lesions on cladodes. The morphological and molecular identification evidenced the isolation of Colletotrichum gloeosporioides, Alternaria alternata, Fusarium lunatum, Curvularia lunata. All these species caused similar symptoms of circular cladodes spot. However, it is noticeable that some lesions showed perforation and detachment of affected tissues by Fusarium lunatum. To our knowledge, this is the first report of the Fusarium lunatum as phytopathogenic fungus of cladodes of prickly pear. The chitosan inhibited the mycelium growth in the seven isolates of phytopathogenic fungi. Chitosan applications diminished the disease incidence caused by C. gloeosporioies and F. lunatum in 40 and 100%, respectively. Likewise, the lesion severity index in cladodes decreased. There are no previous reports about the application of chitosan on cladodes of prickly pears for the control of phytopathogenic fungi. Therefore, this research could contribute to improve the strategies for the management of diseases in prickly pear.
Basolateral glycylsarcosine (Gly-Sar) transport in Caco-2 cell monolayers is pH dependent
Authors: Berthelsen Ragna , Nielsen Carsten Uhd , Brodin Birger
Published: March 2013

Objectives

Transepithelial di/tripeptide transport in enterocytes occurs via the apical proton-coupled peptide transporter, hPEPT1 (SLC15A1) and a basolateral peptide transporter, which has only been characterized functionally. In this study we examined the pH dependency, substrate uptake kinetics and substrate specificity of the transporter.

Methods

We studied the uptake of [14C]Gly-Sar from basolateral solution into Caco-2 cell monolayers grown for 17–22 days on permeable supports, at a range of basolateral pH values.

Key findings

Basolateral Gly-Sar uptake was pH dependent, with a maximal uptake rate at a basolateral pH of 5.5. Uptake of Gly-Sar decreased in the presence of the protonophore nigericin, indicating that the uptake was proton-coupled. The uptake was saturable, with a maximal flux (Vmax) of 408 ± 71, 307 ± 25 and 188 ± 19 pmol/cm2/min (mean ± S.E., n = 3) at basolateral pH 5.0, 6.0 and 7.4, respectively. The compounds Gly-Asp, Glu-Phe-Tyr, Gly-Glu-Gly, Gly-Phe-Gly, lidocaine and, to a smaller degree, para-aminohippuric acid were all shown to inhibit the basolateral uptake of Gly-Sar.

Conclusions

The study showed that basolateral Gly-Sar transport in the intestinal cell line Caco-2 is proton-coupled. The inhibitor profile indicated that the transporter has broad substrate specificity.
Analysing policy interventions to prohibit over‐the‐counter antibiotic sales in four Latin American countries
Authors: Wirtz V. J. , Herrera‐Patino J. J. , Santa‐Ana‐Tellez Y. , Dreser A. , Elseviers M. , Vander Stichele R. H.
Published: March 2013

Objectives

To describe and evaluate policies implemented in Chile, Colombia, Venezuela and Mexico (1995–2009) to prohibit antibiotic OTC sales and explore limitations in available data.

Methods

We searched and analysed legislation, grey literature and peer‐reviewed publications on regulatory interventions and implementation strategies to enforce prohibition of OTC antibiotic sales. We also assessed the impact using private sector retail sales data of antibiotics studying changes in level and consumption trends before and after the policy change using segmented time series analysis. Finally, we assessed the completeness and data quality through an established checklist to test the suitability of the data for analysis of the interventions.

Results

Whereas Chile implemented a comprehensive package of interventions to accompany regulation changes, Colombia's reform was limited to the capital district and Venezuela's limited to only some antibiotics and without awareness campaigns. In Mexico, no enforcement was enacted. The data showed a differential effect of the intervention among the countries studied with a significant change in level of consumption in Chile (−5.56 DID) and in Colombia (−1.00DID). In Venezuela and Mexico, no significant change in level and slope was found. Changes in population coverage were identified as principal limitations of using sales data for evaluating the reform impact.

Conclusion

Retail sales data can be useful when assessing policy impact but should be supplemented by other data sources such as public sector sales and prescription data. Implementing regulatory enforcement has shown some impact, but a sustainable, concerted approach will be needed to address OTC sales in the future.
Constrained optimization of metabolic cost in human hopping
Authors: Gutmann Anne K. , Bertram John E. A.
Published: March 2013

New Findings

What is the central question of this study?

This study evaluates whether constrained optimization of metabolic cost (minimization of metabolic cost within the limitations imposed by constraints) predicts movement selection during vertical human hopping.

What is the main finding and its importance?

Constrained optimization of metabolic cost/height largely predicts movement selection during hopping in frequency‐, height‐ and speed‐constrained conditions. However, subjects sometimes compromise between minimizing metabolic cost/height and maintaining a comfortably sustainable metabolic cost/time. This illustrates how an internal, physiological constraint can interact with external, physical constraints to produce a given behaviour. The principle of constrained optimization may also be applied to understanding how the man‐made environment affects movement selection and energy expenditure in modern urban life.

Constrained optimization of metabolic cost/distance travelled largely predicts the gait parameters selected by humans during walking and running. This study evaluates whether this is also the case for human hopping. Hop frequency (f), height (h) and metabolic energy expenditure were measured in partly constrained (f,hor hop speed,s≡fh, specified), fully constrained (bothfandhspecified) and unconstrained conditions (neitherfnorhspecified) for 4 min trials. Hop frequency and height were also measured in frequency‐constrained (fspecified), fully constrained (maximal height andfspecified) and unconstrained conditions for 15 s trials. Metabolic cost surfaces were constructed from experimental data from the 4 min trials, and the least costly behaviour for each constraint was calculated. Subjects selected the same height–frequency pattern for all three partly constrained conditions because the metabolic cost/height surface for hopping was a slope with no observed minimum. The heights selected for the 15 s frequency‐constrained trials were only slightly lower than maximal, the optimal behaviour predicted by constrained optimization of metabolic cost/height. This supports the hypothesis that constrained optimization of metabolic cost largely predicts movement selection during hopping. However, subjects often chose noticeably lower than optimal heights and higher than optimal frequencies during partly constrained and unconstrained conditions for the 4 min trials. It appears that they selected heights and frequencies that incurred a slightly greater metabolic cost/height in order to reduce metabolic cost/time to a level they could comfortably sustain for 4 min.
Application of Statistical Analysis Techniques to Pipeline On-Bottom Stability Analysis
Authors: Youssef Bassem S. , Cassidy Mark J. , Tian Yinghui
Published: March 2013

Offshore pipelines are increasingly being employed to transport offshore hydrocarbons to onshore processing facilities. Pipelines laid directly on the seabed are subject to a considerable hydrodynamic loading from waves and currents and must be accurately designed for on-bottom stability. Confidence in the stability of pipelines requires appropriate models for their assessment and, in this paper, particular emphasis is placed on achieving an integrated and balanced approach in considering the nonlinearities and uncertainties in the pipe structure, the reaction of the restraining soil, and the hydrodynamic loading applied. A statistical approach is followed by developing a response surface model for the pipeline maximum horizontal displacement within a storm, while including variability in parameters. The Monte Carlo simulation method is used in combination with the developed response surface model to calculate the extreme response statistics. The benefit of this approach is demonstrated and also used to investigate the sensitivity of the on-bottom pipeline simulation for a variety of model input parameters. These results provide guidance to engineers as to what uncertainties are worth reducing, if possible, before a pipe is designed.
Fractal Analysis for Vibrational Signals Created in a Ball-Screw Machine Operating in Short- and Long-Range Tribological Tests
Authors: Chang Min-Chi , Luen Liou Jeng , Wei Chin-Chung , Horng Jeng-Haur , Chiu Yueh-Ling , Chyun Hwang Yih , Fin Lin Jen
Published: March 2013

In the present study, the vibrational and frictional torque signals acquired from the forward-backward movements of a commercial ball-screw system were considered via mono fractal analysis. The short-range tests were carried out in order to investigate the effects of operating conditions, a nut's inner surface roughness and the applied pretension (preload) on the fractal dimension (Ds) and topothesy (G). The long-range test was conducted to observe the variations of vibrational and frictional torque signals and thus the fractal parameters acquired from the ball-screw operations under the condition of no fresh grease supply during the testing process. The effects of the ball-screw rotational speed and pretension on the G parameter of vibrations were greater than the Ds parameter. In the backward movement, the highest G value always occurred at the highest rotational speed (3000 rpm in this study). The Ds parameter generated in the forward movement by the nut's inner surface before polishing produced a value greater than that by the nut with a polished surface. The G parameter related to vibrational amplitudes showed a value before polishing greater than that after polishing. The unusual vibrational signals are assumed to be related to ball passing behavior. Their experimental frequency was verified to be consistent with the frequency predicted by the ball pass theory. An increase in the rotational speed can bring a significant increase in the number of ball-pass signals. The G parameter and its skewness data, defined for the number distribution function of the G peaks, showed values that in general increased with the test time if the fresh grease was not supplied during the long-range test.
Dynamic Features of a Planetary Gear System With Tooth Crack Under Different Sizes and Inclination Angles
Authors: Chen Zaigang , Shao Yimin
Published: March 2013

Planetary gears are widely used in the industry due to their advantages of compactness, high power-to-weight ratios, high efficiency, and so on. However, planetary gears such as that in wind turbine transmissions always operate under dynamic conditions with internal and external load fluctuations, which accelerate the occurrence of gear failures, such as tooth crack, pitting, spalling, wear, scoring, scuffing, etc. As one of these failure modes, gear tooth crack at the tooth root due to tooth bending fatigue or excessive load is investigated; how it influences the dynamic features of planetary gear system is studied. The applied tooth root crack model can simulate the propagation process of the crack along tooth width and crack depth. With this approach, the mesh stiffness of gear pairs in mesh is obtained and incorporated into a planetary gear dynamic model to investigate the effects of the tooth root crack on the planetary gear dynamic responses. Tooth root cracks on the sun gear and on the planet gear are considered, respectively, with different crack sizes and inclination angles. Finally, analysis regarding the influence of tooth root crack on the dynamic responses of the planetary gear system is performed in time and frequency domains, respectively. Moreover, the differences in the dynamic features of the planetary gear between the cases that tooth root crack on the sun gear and on the planet gear are found.
Analysis of S Characteristics and Pressure Pulsations in a Pump-Turbine With Misaligned Guide Vanes
Authors: Sun Hui , Xiao Ruofu , Liu Weichao , Wang Fujun
Published: March 2013

Growing environmental concerns and the need for better power balancing and frequency control have increased attention in renewable energy sources such as the reversible pump-turbine which can provide both power generation and energy storage. Pump-turbine operation along the S-shaped curve can lead to difficulties in loading the rejection process with unusual increases in water pressure, which lead to machine vibrations. Pressure fluctuations are the primary reason for unstable operation of pump-turbines. Misaligned guide vanes (MGVs) are widely used to control the stability in the S region. There have been experimental investigations and computational fluid dynamics (CFD) simulations of scale models with aligned guide vanes and MGVs with spectral analyses of the S curve characteristics and the pressure pulsations in the frequency and time-frequency domains at runaway conditions. The course of the S characteristic is related to the centrifugal force and the large incident angle at low flow conditions with large vortices forming between the guide vanes and the blade inlets and strong flow recirculation inside the vaneless space as the main factors that lead to the S-shaped characteristics. Preopening some of the guide vanes enables the pump-turbine to avoid the influence of the S characteristic. However, the increase of the flow during runaway destroys the flow symmetry in the runner leading to all asymmetry forces on the runner that leads to hydraulic system oscillations. The MGV technique also increases the pressure fluctuations in the draft tube and has a negative impact on stable operation of the unit.
Model of Flow in the Side Chambers of an Industrial Centrifugal Pump for Delivering Viscous Oil
Authors: Li Wenguang
Published: March 2013

A series of experiments has been conducted to identify the effects of both fluid viscosity and wear-rings gap on the performance of a low specific speed industrial centrifugal pump of type 65Y60 for transporting viscous oils by the author group. Unfortunately, the experimental results remained unexplained on a fluid dynamics base. To remedy this problem, a highly viscous oil flow model and computational method in the side chambers in that pump were proposed based on the existing theoretical and experimental results. The flow coupling between the chambers and the gaps of the wear-rings and/or the balance holes was realized. The model was validated by making use of the existing experiment data in the chamber between a rotating disk and the walls of a stationary cylindrical container. Then the flow model was applied into the two side chambers in that pump when the wear-rings clearances and liquid viscosity were changed. The results demonstrated that the flow model is sensitive to wear-rings gap, liquid viscosity, the roughness of the wet walls of the chambers, and leakage flow rate. For this pump, an enlarged clearance can improve the mechanical efficiency, but the increment in the efficiency is unable to compensate for the considerable drop in the volumetric efficiency, causing the gross efficiency not be improved, especially at a high viscosity.
Active Contours With Stochastic Fronts and Mechanical Topology Optimization
Authors: Kasaiezadeh Alireza , Khajepour Amir
Published: March 2013

Active contours with stochastic fronts (ACSF) is developed and investigated in this article to address the dependency of the existing algorithms of topology optimization on the initial guesses. The promising results of ACSF confirms that the use of this approach leads to higher chance of escaping from local solutions compared to the classic level set method. ACSF as a special case of the stochastic active contours (SAC), has a simplified structure that makes its implementation easier, and at the same time it has a rigorous mathematical proof of convergence. Although propitious, there is still a slight chance of trapping scenarios for ACSF that is observed in the presented results.
An Efficient Numerical Method With a Parallel Computational Strategy
for Solving Arbitrarily Shaped Inclusions in Elastoplastic Contact
Problems
Authors: Wang Zhanjiang , Jin Xiaoqing , Zhou Qinghua , Ai Xiaolan , Keer Leon M. , Wang Qian
Published: March 2013

The plastic zone developed during elastoplastic contact may be effectively modeled as an inclusion in an isotropic half space. This paper proposes a simple but efficient computational method to analyze the stresses caused by near surface inclusions of arbitrary shape. The solution starts by solving a corresponding full space inclusion problem and proceeds to annul the stresses acting normal and tangential to the surface, where the numerical computations are processed by taking advantage of the fast Fourier transform techniques with a parallel computing strategy. The extreme case of a cuboidal inclusion with one facet on the surface of the half space is chosen to validate the method. When the surface truncation domain is extended sufficiently and the grids are dense enough, the results based on the new approach are in good agreement with the exact solutions. When solving a typical elastoplastic contact problem, the present analysis is roughly two times faster than the image inclusion approach and six times faster than the direct method. In addition, the present work demonstrates that a significant enhancement in the computational efficiency can be achieved through the introduction of parallel computation.
Generation of voxelized breast phantoms from surgical mastectomy specimens
Authors: Michael O'Connor J. , Das Mini , Dider Clay S. , Mahd Mufeed , Glick Stephen J.
Published: March 2013

Purpose:

In the research and development of dedicated tomographic breast imaging systems, digital breast object models, also known as digital phantoms, are useful tools. While various digital breast phantoms do exist, the purpose of this study was to develop a realistic high‐resolution model suitable for simulating three‐dimensional (3D) breast imaging modalities. The primary goal was to design a model capable of producing simulations with realistic breast tissue structure.

Methods:

The methodology for generating an ensemble of digital breast phantoms was based on imaging surgical mastectomy specimens using a benchtop, cone‐beam computed tomography system. This approach allowed low‐noise, high‐resolution projection views of the mastectomy specimens at each angular position. Reconstructions of these projection sets were processed using correction techniques and diffusion filtering prior to segmentation into breast tissue types in order to generate phantoms.

Results:

Eight compressed digital phantoms and 20 uncompressed phantoms from which an additional 96 pseudocompressed digital phantoms with voxel dimensions of 0.2 mm3 were generated. Two distinct tissue classification models were used in forming breast phantoms. The binary model classified each tissue voxel as either adipose or fibroglandular. A multivalue scaled model classified each tissue voxel as percentage of adipose tissue (range 1%–99%). Power spectral analysis was performed to compare simulated reconstructions using the breast phantoms to the original breast specimen reconstruction, and fits were observed to be similar.

Conclusions:

The digital breast phantoms developed herein provide a high‐resolution anthropomorphic model of the 3D uncompressed and compressed breast that are suitable for use in evaluating and optimizing tomographic breast imaging modalities. The authors believe that other research groups might find the phantoms useful, and therefore they offer to make them available for wider use.
Development of a fast and feasible spectrum modeling technique for flattening filter free beams
Authors: Cho Woong , Bush Karl , Mok Ed , Xing Lei , Suh Tae‐Suk
Published: March 2013

Purpose:

To develop a fast and robust technique for the determination of optimized photon spectra for flattening filter free (FFF) beams to be applied in convolution/superposition dose calculations.

Methods:

A two‐step optimization method was developed to derive optimal photon spectra for FFF beams. In the first step, a simple functional form of the photon spectra proposed by Ali [“Functional forms for photon spectra of clinical linacs,” Phys. Med. Biol. 57, – (2011)] 10.1088/0031‐9155/57/1/31 is used to determine generalized shapes of the photon spectra. In this method, the photon spectra were defined for the ranges of field sizes to consider the variations of the contributions of scattered photons with field size. Percent depth doses (PDDs) for each field size were measured and calculated to define a cost function, and a collapsed cone convolution (CCC) algorithm was used to calculate the PDDs. In the second step, the generalized functional form of the photon spectra was fine‐tuned in a process whereby the weights of photon fluence became the optimizing free parameters. A line search method was used for the optimization and first order derivatives with respect to the optimizing parameters were derived from the CCC algorithm to enhance the speed of the optimization. The derived photon spectra were evaluated, and the dose distributions using the optimized spectra were validated.

Results:

The optimal spectra demonstrate small variations with field size for the 6 MV FFF beam and relatively large variations for the 10 MV FFF beam. The mean energies of the optimized 6 MV FFF spectra were decreased from 1.31 MeV for a 3 × 3 cm2 field to 1.21 MeV for a 40 × 40 cm2 field, and from 2.33 MeV at 3 × 3 cm2 to 2.18 MeV at 40 × 40 cm2 for the 10 MV FFF beam. The developed method could significantly improve the agreement between the calculated and measured PDDs. Root mean square differences on the optimized PDDs were observed to be 0.41% (3 × 3 cm2) down to 0.21% (40 × 40 cm2) for the 6 MV FFF beam, and 0.35% (3 × 3 cm2) down to 0.29% (40 × 40 cm2) for the 10 MV FFF beam. The first order derivatives from the functional form were found to improve the speed of computational time up to 20 times compared to the other techniques.

Conclusions:

The derived photon spectra resulted in good agreements with measured PDDs over the range of field sizes investigated. The suggested method is easily applicable to commercial radiation treatment planning systems since it only requires measured PDDs as input.
Inhibition of PRC2 Activity by a Gain-of-Function H3 Mutation Found in Pediatric Glioblastoma
Authors: Lewis Peter W. , Müller Manuel M. , Koletsky Matthew S. , Cordero Francisco , Lin Shu , Banaszynski Laura A. , Garcia Benjamin A. , Muir Tom W. , Becher Oren J. , Allis C. David
Published: March 2013

EZ Inhibition

Missense mutations in the core constituents of the genome packaging material, chromatin, have been implicated in several of human cancers. Nucleosomes are made up of histones, and a mutation of lysine 27 (K27) to methionine in the N-terminal tail of histone variants H3.3 and H3.1 has been identified in various pediatric gliomas.

Lewis
et al.

(p.
857
, published online 28 March; see the Perspective by

Morgan and Shilatifard

) show that the polycomb enzyme complex, which can epigenetically modify K27 by addition of a methyl group—and which is often a silencing signal—is itself potently inhibited by replacement of the H3.3/3.1 K27 by methionine. The inhibition of the EZH2 subunit causes an overall reduction of K27 methylation. Methionine mutants of other methylated lysine residues in histone H3 cause similar reductions in methylation levels of the cognate lysine, altering the epigenetic profiles of such cancer cells.
Photochemical Route for Accessing Amorphous Metal Oxide Materials for Water Oxidation Catalysis
Authors: Smith Rodney D. L. , Prévot Mathieu S. , Fagan Randal D. , Zhang Zhipan , Sedach Pavel A. , Siu Man Kit Jack , Trudel Simon , Berlinguette Curtis P.
Published: March 2013

Amorphous and More Active

The electrochemical generation of hydrogen from water could help in the storage of energy generated by renewable resources at off-peak times. However, catalysts for the slow step of this reaction, the oxygen evolution reaction (OER), are based on oxides of noble metals (iridium and ruthenium) that have limited abundance. A strategy for improving the performance of earth-abundant elements is to explore mixed-metal oxides and to prepare these as amorphous phases.

Smith
et al.

(p.
60
, published online 28 March) developed a general method for preparing amorphous oxides, based on photodecomposition of organometallic precursors. Amorphous mixed-metal oxides of iron, nickel, and cobalt were more active than comparable crystalline materials and provided OER performance comparable to noble metal oxides.
Rational HIV Immunogen Design to Target Specific Germline B Cell Receptors
Authors: Jardine Joseph , Julien Jean-Philippe , Menis Sergey , Ota Takayuki , Kalyuzhniy Oleksandr , McGuire Andrew , Sok Devin , Huang Po-Ssu , MacPherson Skye , Jones Meaghan , Nieusma Travis , Mathison John , Baker David , Ward Andrew B. , Burton Dennis R. , Stamatatos Leonidas , Nemazee David , Wilson Ian A. , Schief William R.
Published: March 2013

Building Better Vaccines

In the past few years, several highly potent, broadly neutralizing antibodies (bNAbs) specific for the gp120 envelope protein of HIV-1 have been discovered. The goal of this work is to use this information to inform the design of vaccines that are able to induce such antibodies (see the Perspective by

Crowe

). However, because of extensive somatic hypermutation, the epitope bound by these antibodies often does not bind to the germline sequence.

Jardine
et al.

(p.
711
, published online 28 March; see the cover) used computational analysis and in vitro screening to design an immunogen that could bind to VRC01-class bNAbs and to their germline precursors.

Georgiev
et al.

(p.
751
) took advantage of the fact that only four sites on the HIV viral envelope protein seem to bind bNAbs, and sera that contain particular bNAbs show characteristic patterns of neutralization. An algorithm was developed that could successfully delineate the neutralization specificity of antibodies present in polyclonal sera from HIV-infected patients.
Irreversible Does Not Mean Unavoidable
Authors: Matthews H. Damon , Solomon Susan
Published: March 2013

Carbon dioxide emissions cuts implemented today would affect the rate of future global warming immediately.
Draft Whole-Genome Sequence of Bacillus sonorensis Strain L12, a Source of Nonribosomal Lipopeptides
Authors: Adimpong David B. , Sørensen Kim I. , Nielsen Dennis S. , Thorsen Line , Rasmussen Thomas B. , Derkx Patrick M. F. , Jespersen Lene
Published: March 2013

The
Bacillus sonorensis
L12 draft genome sequence is approximately 4,647,754 bp in size with a G+C content of 45.2%. Over 86% of the genome contains protein-encoding genes, including several gene clusters for
de novo
biosynthesis of the nonribosomal lipopeptides iturin, bacitracin, and fengycin, which could mean that the strain exhibits antifungal effects.
Draft Genome Sequence of Rhodococcus qingshengii Strain BKS 20-40
Authors: Bala Monu , Kumar Shailesh , Raghava Gajendra Pal Singh , Mayilraj Shanmugam
Published: March 2013

We report the 5.8-Mb genome sequence of
Rhodococcus qingshengii
strain BKS 20-40, isolated from a palm tree rhizosphere soil sample from Bhitarkanika National Park, Odisha, India. The strain is capable of degrading cholesterol moiety. The draft genome of strain BKS 20-40 consists of 6,601,618 bp, with 62.4% G+C content.
Transvenous Onyx embolization of a subependymal deep arteriovenous malformation with a single drainage vein: technical note
Authors: Martínez-Galdámez Mario , Saura Pedro , Saura Javier , Muñiz Jesus , Albisua Julio , Pérez-Higueras Antonio
Published: March 2013

Cerebral arteriovenous malformations (AVMs) are uncommon. Treatment options include embolization, radiosurgery and surgery, separately or combined, the final goal being complete occlusion of the malformation. We describe the case of a symptomatic small subependymal AVM with a single deep drainage vein previously treated unsuccessfully by radiosurgery and transarterial embolization. The AVM was successfully embolized transvenously using Onyx, achieving complete occlusion in a single treatment session.
Assessing clinical reasoning using a script concordance test with electrocardiogram in an emergency medicine clerkship rotation
Authors: Boulouffe Caroline , Doucet Bruno , Muschart Xavier , Charlin Bernard , Vanpee Dominique
Published: March 2013

Objectives

Script concordance tests (SCTs) can be used to assess clinical reasoning, especially in situations of uncertainty, by comparing the responses of examinees with those of emergency physicians. The examinee's answers are scored based on the level of agreement with responses provided by a panel of experts. Emergency physicians are frequently uncertain in the interpretation of ECGs. Thus, the aim of this study was to validate an SCT combined with an ECG.

Methods

An SCT-ECG was developed. The test was administered to medical students, residents and emergency physicians. Scoring was based on data from a panel of 12 emergency physicians. The statistical analyses assessed the internal reliability of the SCT (Cronbach's α) and its ability to discriminate between the different groups (ANOVA followed by Tukey's post hoc test).

Results

The SCT-ECG was administered to 21 medical students, 19 residents and 12 emergency physicians. The internal reliability was satisfactory (Cronbach's α=0.80). Statistically significant differences were found between the groups (F0.271=21.07; p<0.0001). Moreover, significant differences (post hoc test) were detected between students and residents (p<0.001), students and experts (p<0.001), and residents and experts (p=0.017).

Conclusions

This SCT-ECG is a valid tool to assess clinical reasoning in a context of uncertainty due to its high internal reliability and its ability to discriminate between different levels of expertise.
IGFBP-5 overexpression as a poor prognostic factor in patients with urothelial carcinomas of upper urinary tracts and urinary bladder
Authors: Liang Peir-In , Wang Yu-Hui , Wu Ting-Feng , Wu Wen-Ren , Liao Alex C , Shen Kun-Hung , Hsing Chung-Hsi , Shiue Yow-Ling , Huang Hsuan-Ying , Hsu Han-Ping , Chen Li-Tzon , Lin Ching-Yih , Tai Chein , Wu Jui-Yu , Li Chien-Feng
Published: March 2013

Background

Urothelial carcinoma (UC) is prevalent worldwide. Dysregulation of cell growth is a critical event of tumorigenesis and has not been assessed systemically in UC. We thus assessed the published transcriptome of urinary bladder urothelial carcinoma (UBUC) and identifiedinsulin-like growth factor-binding protein-5(IGFBP-5) as the most significantly upregulated gene associated with the regulation of cell growth. Moreover, validated by using public domain data set, IGFBP-5 expression also significantly predicted worse outcome. IGFBP-5 is one of the binding proteins that regulate insulin-like growth factors (IGFs) and its significance has not been comprehensively evaluated in UCs.

Methods

Using immunohistochemistry, we evaluated the IGFBP-5 expression status and its associations with clinicopathological features and survival in 340 cases of upper urinary tract urothelial carcinoma (UTUC) and 295 cases of UBUC. Western blot analysis was used to evaluate IGFBP-5 protein expression in human urothelial cell (HUC) lines.

Results

IGFBP-5 overexpression was significantly associated with advanced pT stage (p<0.001), high histological grade (UTUC, p<0.001; UBUC, p=0.035), lymph node metastasis (UTUC, p=0.006; UBUC, p=0.004), vascular invasion (UTUC, p<0.001; UBUC, p=0.003), perineural invasion (UTUC, p=0.034; UBUC, p=0.021) and frequent mitosis (UTUC, p<0.001; UBUC, p=0.023). IGFBP-5 overexpression also independently predicted poor disease-specific survival and metastasis-free survival in both groups of patients. Western blot analysis showed IGFBP-5 protein as overexpressed in human urothelial cancer cell lines and not in normal urothelial cancer cells.

Conclusions

IGFBP-5 plays an important role in tumour progression in UC. Its overexpression is associated with advanced tumour stage and conferred poorer clinical outcome.
Clinicopathological significance of HER2/neu genetic heterogeneity in HER2/neu non-amplified invasive breast carcinomas and its concurrent axillary metastasis
Authors: Shafi Hedyeh , Astvatsaturyan Kristine , Chung Fai , Mirocha James , Schmidt Michael , Bose Shikha
Published: March 2013

Background

HER2/neu (HER2) is a significant prognostic marker for breast carcinomas. Recently, new guidelines definingHER2genetic heterogeneity (GH) were published by the College of American Pathologists.

Aims

To determine the prevalence ofHER2GH as defined in primary invasive breast carcinoma, to determine its relationship with prognostic variables and to investigate its impact on concurrent axillary metastasis.

Methods

235 consecutive infiltrating breast carcinomas were evaluated for GH (defined as presence of 5–50% of neoplastic cells withHER2/CEP17 ratio >2.2) using fluorescence in situ hybridisation. Pathological features of carcinomas with GH were compared with those lacking GH. GH was also evaluated in a subset of 37 paired primary carcinomas and its concurrent axillary nodal metastases using dual in situ hybridisation.

Results

HER2GH was noted in 27% ofHER2 negativebreast carcinomas. These carcinomas demonstrated aggressive characteristics (larger size, higher grade and greater incidence of lymph node metastasis) in comparison withHER2negative cases without GH. Higher levels of GH were associated with the equivocalHER2status. GH was maintained in the concurrent lymph node metastases with some variations; however, two cases with clusters ofHER2amplified cells in the primary carcinoma showedHER2amplification in the nodal metastasis.

Conclusions

HER2GH is present in 27% of breast carcinomas, portends an aggressive phenotype and contributes to the equivocalHER2status. Evaluation of the HER2 status in nodal metastasis of select primary carcinomas with GH may be beneficial before treatment selection.
The surgical anatomy of the perineum
Authors: Mahadevan V , Chandak P
Published: March 2013

The anatomy of the perineum and pelvis is complex. Those outside the specialist fields of colorectal surgery, urology and gynaecological surgery often have a less-than-complete understanding of the anatomical details of this region. The recent increase in complicated pelvic and perineal injuries caused by the detonation of Improvised Explosive Devices has brought into sharp focus, the importance of this area of surgical anatomy. The following article describes, in a systematic and detailed manner, the anatomy of the urogenital and anal regions of the perineum. The terminology in relation to the fascial layers and structures encountered in the perineum is elucidated. In addition, the surgical anatomy of the scrotum and its contents and the ligamentous support of the penis are described, with clear illustrations throughout.

It is intended that this article will go some way towards clarifying the anatomy underlying the surgical management of complex perineal/pelvic injuries, and benefit both the specialist and non-specialist military surgeon.
Blast injury to the perineum
Authors: Sharma Davendra M , Webster C E , Kirkman-Brown J , Mossadegh S , Whitbread T ,   on behalf of the Genitourinary Working Group (Trauma)
Published: March 2013

Recent military operations have resulted in a small but significant number of military personnel suffering severe perineal injuries. In association with lower limb amputation and pelvic fracture, this complex is described as the ‘signature injury’ of the current conflict in Afghanistan. There are significant consequences of surviving severe perineal injury but the experience of managing these casualties is limited. This article gives an overview of the processes developed to meet these challenges and introduces a series of articles which examine the subject in finer detail.
The development and introduction of ballistic protection of the external genitalia and perineum
Authors: Lewis Eluned A , Pigott M A , Randall A , Hepper A E
Published: March 2013

In response to an Urgent Operational Requirement, the UK Ministry of Defence (MoD) investigated, designed, developed, trialled and subsequently fielded a Tiered Pelvic Protection System to service personnel deployed on Operation HERRICK in Afghanistan. An Urgent Statement of User Requirement (USUR) was drafted in order to equip service personnel with protection for the groin, perineum, buttocks and upper thigh areas from the effects of buried Improvised Explosive Devices (IEDs). Injuries to the groin and pelvic area from buried IEDs can have severe physiological and psychological impact; therefore the aim of the pelvic protection was to reduce the number and severity of such injuries and to improve the outcome, both in terms of quality of life of the survivors and increase the chances of survival. The aim of this paper is to outline some of the research and development that contributed to the design(s) of the Tiered Pelvic Protection System; describe the components of, and report the medical success of, the Tiered Pelvic Protection System.
The psychological challenge of genital injury
Authors: Frappell-Cooke W , Wink P , Wood A
Published: March 2013

Introduction

Injuries sustained from Improvised Explosive Devices (IEDs) can have a devastating impact on bodily integrity; physical injuries can be severe and include traumatic amputation of limbs, pelvic fracture, abdominal trauma, extremity fragmentation wounds and genital trauma. Soldiers suffering from genital trauma can experience overwhelming emotions and adjusting to their injuries is a process that occurs over time, that some find easier than others. This paper explores current practice and identifies guidelines for psychological interventions within this arena.

Methods

Relevant associated literature has been reviewed to identify the long-term consequences of genital trauma and to ascertain best practice in supporting this patient population. Current practices within the Royal Centre for Defence Medicine (RCDM) and the Defence Medical Rehabilitation Centre (DMRC) Headley Court have been explored.

Results

There is little published literature in this area. Therefore, in respect of guiding treatment of this patient population, related research on the psychological consequences of prostate and penile cancer, limb amputation, acquired infertility and acquired disability has been used as a base to inform interventions. Current practices at RCDM and DMRC have been found to support interventions within related areas.

Conclusions

There is no published evidence base to guide psychological interventions for genital trauma. Professional multidisciplinary intervention will potentially be beneficial in establishing the long-term needs of this patient population, together with qualitative research exploring the experience of soldiers suffering genital trauma.
Patients rebuilt: Dr Auguste Rollier's heliotherapeutic portraits, c.1903–1944
Authors: Woloshyn Tania Anne
Published: March 2013

This article explores and critically contextualises the photographic production of heliotherapist Auguste Rollier (1874–1954), specifically the ‘patient portraits’ photographed at his Leysin sanatoria over a substantial period of four decades, c.1903–1944. It argues that these photographs, ignored in secondary literature, were particularly persuasive in communicating the natural healing powers of sunlight and through their international dissemination brought Rollier's work professional acclaim and prestige. Always presenting anonymous patients, and most often children, the images produced for Rollier's work interweave aesthetic and medical interests. Whether through the aesthetics of the photograph, of the positioning and appearance of the patient's body, or of the language used to describe these, issues of beauty and harmony were significant preoccupations for Rollier and the dissemination of his heliotherapeutic practice. The article argues that these aesthetic preoccupations drove his work, that the patient's progress and final cure, and thus the therapy's efficacy, were determined by aesthetic criteria—read through the body itself and its photographic representation. This legibility, of the body and its photography, was crucial to articulating the sun's perceived natural ability to improve, heal and even ‘rebuild’ individual patients into socially and physically productive citizens. As such, the article contends, Rollier privileged image over word, conceiving the former as possessing an unequalled ‘eloquence’ to communicate the efficacy and social potential of heliotherapy.
Size and anatomic location of ruptured intracranial aneurysms in patients with single and multiple aneurysms: a retrospective study from a single center
Authors: Jagadeesan Bharathi Dasan , Delgado Almandoz Josser E , Kadkhodayan Yasha , Derdeyn Colin P , Cross Dewitte T , Chicoine Michael R , Rich Keith M , Zipfel Gregory J , Dacey Ralph G , Moran Christopher J
Published: March 2013

Background and purpose

The difference in the relationship between the size of intracranial aneurysms (IAs) and their risk of rupture in patients with singe IAs versus those with multiple IAs is unclear. We sought to retrospectively analyze the size of ruptured IAs (RIAs) in patients with single and multiple IAs in order to study this relationship further.

Methods

We retrospectively measured the size and location of RIAs in all patients who presented to our institute with an acute subarachnoid hemorrhage between 1 January 2005 and 31 December 2010. The IAs were classified by size into very small IAs or VSAs (≤3 mm), small IAs or SAs (>3 mm but ≤7 mm) and others (>7 mm).

Results

379 patients (281 with a single IA, Group 1 and 98 with multiple IAs, Group 2) with 419 treated RIAs were included in the study. VSAs and SAs constituted the majority of RIAs in both groups (33.5% and 45.2% in Group 1 and 24.6% and 50.7% in Group 2) and the mean size of the RIAs was not different between the two groups. VSAs constituted almost two-thirds of all RIAs in certain locations whereas IAs > 7 mm in size did not constitute more than a third of the RIAs at any of the arterial locations.

Conclusions

The high incidence of VSAs, particularly in certain locations in both patient subgroups, suggests that current diagnostic, prognostic and therapeutic options in the management of IAs should be more tailored towards the management of these difficult-to-treat lesions.
High-Speed AFM and Applications to Biomolecular Systems
Authors: Ando Toshio , Uchihashi Takayuki , Kodera Noriyuki
Published: March 2013

Directly observing individual protein molecules in action at high spatiotemporal resolution has long been a holy grail for biological science. This is because we long have had to infer how proteins function from the static snapshots of their structures and dynamic behavior of optical makers attached to the molecules. This limitation has recently been removed to a large extent by the materialization of high-speed atomic force microscopy (HS-AFM). HS-AFM allows us to directly visualize the structure dynamics and dynamic processes of biological molecules in physiological solutions, at subsecond to sub-100-ms temporal resolution, without disturbing their function. In fact, dynamically acting molecules such as myosin V walking on an actin filament and bacteriorhodopsin in response to light are successfully visualized. In this review, we first describe theoretical considerations for the highest possible imaging rate of this new microscope, and then highlight recent imaging studies. Finally, the current limitation and future challenges to explore are described.
The Scotia Arc: Genesis, Evolution, Global Significance
Authors: Dalziel Ian W.D. , Lawver Lawrence A. , Norton Ian O. , Gahagan Lisa M.
Published: March 2013

The Scotia arc is the eastward-closing loop of mountains and locally emergent submarine ridges extending from the southernmost Andes through the active South Sandwich volcanic arc to the Antarctic Peninsula. Its origins lie in the Jurassic initial fragmentation of Gondwana. This fragmentation involved extreme intercratonic extension, Pacificward translation of rotating crustal blocks, and an ignimbrite flare-up. Relative motion between South America, Africa, and East Antarctica during the opening of the southern ocean basins resulted in mid-Cretaceous uplift of the Pacific margin cordillera and translation of elevated crustal blocks eastward to form the North and South Scotia Ridges. The South Sandwich volcanic arc system originated in Neogene westward-directed subduction beneath oceanic crust formed between South America and Antarctica and serves as an excellent tectonic laboratory. The physiography of the entire Scotia arc region has profoundly influenced the onset and development of the Antarctic Circumpolar Current and migration of marine and terrestrial biota.
Fetal Origins and Parental Responses
Authors: Almond Douglas , Mazumder Bhashkar
Published: March 2013

How do parental investments respond to health endowments at birth? Recent studies have combined insights from an earlier theoretical literature on household resource allocation with improved identification strategies to capture causal effects of early life health shocks. We describe empirical challenges in identifying behavioral responses and how recent studies have sought to address these. We then discuss the emerging literature on dynamic complementarities in parental investments arising from the staged, developmental nature of capability production and how capabilities may have multiple dimensions. The bulk of the empirical evidence to date suggests that parental investments reinforce initial endowment differences.