bluuebunny/crossref_metadata_2025 huggingface dataset:
Image segmentation model based on adaptive adjustment of global and local information
Authors: Wang Xianghai , Song Ruoxi , Zhang Chong , Li Chang , Fang Lingling
Published: August 2016

In this article, an adaptive mixture model for image segmentation that synthesizes both global information and local information using a new adaptive balance function has been proposed. Given the variety of possible image characteristics that may have to be processed, the proposed model can adaptively adjust the weighting to drive curve evolution trends and states. In this way, the intensity information of weak boundaries and complex backgrounds can be extracted more precisely, thus enabling the model to produce better results for low‐contrast images and complex structures. In addition, a Gaussian filtering process has been added to the model to smooth and standardize the level set function, and a parameter has been introduced to speed up the curve evolution. A penalty term is also used to eliminate the need for complex re‐initialization procedures. Experimental results for various kinds of images efficiently demonstrate the good performance of the proposed model in terms of both speed and accuracy. © 2016
Wiley Periodicals, Inc. Int J Imaging Syst Technol, 26, 179–187, 2016
Earlier detection of cancer regions from MR image features and SVM classifiers
Authors: Rajaguru Harikumar , Ganesan Karthick , Bojan Vinoth Kumar
Published: August 2016

In this article, we examine the use of several segmentation algorithms for medical image classification. This work detects the cancer region from magnetic resonance (MR) images in earlier stage. This is accomplished in three stages. In first stage, four kinds of region‐based segmentation techniques are used such asK‐means clustering algorithm, expectation–maximization algorithm, partial swarm optimization algorithm, and fuzzy c‐means algorithm. In second stage, 18 texture features are extracting using gray level co‐occurrence matrix (GLCM). In stage three, classification is based on multi‐class support vector machine (SVM) classifier. Finally, the performance analysis of SVM classifier is analyzed using the four types of segmentation algorithm for a group of 200 patients (32—Glioma, 32—Meningioma, 44—Metastasis, 8—Astrocytoma, 72—Normal). The experimental results indicate that EM is an efficient segmentation method with 100% accuracy. In SVM, quadratic and RBF (σ = 0.5) kernel methods provide the highest classification accuracy compared to all other SVM kernel methods. © 2016 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 26, 196–208, 2016
Interaction‐tailored cell aggregates in alginate hydrogels for enhanced chondrogenic differentiation
Authors: Park Honghyun , Kim Doyun , Lee Kuen Yong
Published: August 2016

Controlling cell–matrix interactions is critical when transferring cells into the body using a scaffold, which can be elaborately tailored to successfully engineer the desired tissue. In this study, ATDC5 cells were encapsulated within alginate hydrogels and their chondrogenic differentiation was investigated in vitro. Cell–matrix interactions were introduced using RGD peptides, which improved the viability of encapsulated cells and enhanced the formation of condensed structures similar to a chondrogenic nodule. When N‐cadherin of ATDC5 cells was blocked, the encapsulated cells did not form an aggregate, and chondrogenic differentiation could not be induced. Preformed cell aggregates with defined cell numbers in RGD‐modified alginate gels retained adequate N‐cadherin‐mediated cell–cell interactions and increased chondrogenic marker gene expression, compared with the homogeneously dispersed cells in the gels. This approach may be useful to promote chondrogenesis with relatively few cells if they are encapsulated into a scaffold as a form of aggregates. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 42–50, 2017.
In vitro cyclic compressive loads potentiate early osteogenic events in engineered bone tissue
Authors: Ravichandran Akhilandeshwari , Lim Jing , Chong Mark Seow Khoon , Wen Feng , Liu Yuchun , Pillay Yaesshna T. , Chan Jerry K. Y. , Teoh Swee‐Hin
Published: August 2016

Application of dynamic mechanical loads on bone and bone explants has been reported to enhance osteogenesis and mineralization. To date, published studies have incorporated a range of cyclic strains on 3D scaffolds and platforms to demonstrate the effect of mechanical loading on osteogenesis. However, most of the loading parameters used in these studies do not emulate the in vivo loading conditions. In addition, the scaffolds/platforms are not representative of the native osteoinductive environment of bone tissue and hence may not be entirely accurate to study the in vivo mechanical loading. We hypothesized that biomimicry of physiological loading will potentiate accelerated osteogenesis in bone grafts. In this study, we present a compression bioreactor system that applies cyclic compression to cellular grafts in a controlled manner. Polycaprolactone‐β Tricalcium Phosphate (PCL‐TCP) scaffolds seeded with Mesenchymal Stem Cells (MSC) were cyclically compressed in bioreactor for a period of 4 weeks at 1 Hz and physiological strain value of 0.22% for 4 h per day. Gene expression studies revealed increased expressions of osteogenesis‐related genes (Osteonectin and COL1A1) on day 7 of cyclic loading group relative to its static controls. Cyclic compression resulted in a 3.76‐fold increase in the activity of Alkaline Phosphatase (ALP) on day 14 when compared to its static group (p < 0.001). In addition, calcium deposition of cyclic loading group was found to attain saturation on day 14 (1.96 fold higher than its static scaffolds). The results suggested that cyclic, physiological compression of stem cell‐seeded scaffolds generated highly mineralized bone grafts. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2366–2375, 2017.
Treatment of biliary tract stones after gastrectomy in the era of laparoscopic cholecystectomy
Authors: Hashimoto Masaji , Imamura Tsunao , Tamura Tetsuo , Koyama Rikako , Koizumi Yuko , Makuuchi Mikio , Matsuda Masamichi , Watanabe Goro
Published: August 2016

Background

The incidence of biliary tract stones has widely been reported to be high after gastrectomy. Treatment of biliary tract stones in post‐gastrectomy patients was examined retrospectively, particularly minimally invasive therapy with laparoscopic cholecystectomy for gallbladder stones and endoscopic bile duct lithotomy for common bile duct stones.

Methods

Treatment of 122 post‐gastrectomy patients with biliary tract stones was examined retrospectively from 1995 to April 2015.

Results

Symptomatic biliary tract stones were found in 3.7% of post‐gastrectomy patients. The frequency of bile duct stones was higher in post‐gastrectomy patients with gallbladder stones (44%) than in the nongastrectomy patients (11%). Laparoscopic cholecystectomy was carried out in 84% of the patients with gallbladder stones. Endoscopic bile duct lithotomy was feasible in 89% of patients with common bile duct stones.

Conclusions

Laparoscopic cholecystectomy was feasible for removing gallbladder stones after gastrectomy. Endoscopic bile duct lithotomy followed by laparoscopic cholecystectomy was a good option for patients in whom endoscopic intervention could be performed. On the other hand, choledochoenterostomy could be a good option for patients in whom endoscopic bile duct lithotomy cannot be performed, particularly considering the risk of recurrent bile duct stones.
Fat‐suppressed T2 mapping of femoral cartilage in the porcine knee joint: A comparison with conventional T2 mapping
Authors: Ryu Young Jin , Hong Sung Hwan , Kim Hyeonjin , Choi Ja‐Young , Yoo Hye Jin , Kang Yusuhn , Park Sang Joon , Kang Heung Sik
Published: August 2016

Purpose

To investigate the effect of fat suppression on T2 mapping of the articular cartilage in the porcine knee joint using magnetic resonance imaging (MRI).

Materials and Methods

Eleven porcine knee joints were harvested en bloc with intact capsules. We performed T2 mapping of the articular cartilage in the medial femoral condyle at 3T either with (fat‐suppressed T2 mapping) or without (conventional T2 mapping) fat suppression in the sagittal plane under two frequency‐encoding directions: from superior to inferior (SI) and inferior to superior (IS). Two observers measured the T2 values of the medial femoral condyle cartilage in four regions: in the anterior oblique, central horizontal, posterior oblique, and posterior vertical portions. We evaluated reproducibility of the fat‐suppressed and conventional T2 mapping by changing the frequency‐encoding direction.

Results

The mean T2 values of fat‐suppressed T2 mapping were significantly lower than those of conventional T2 mapping for five of eight comparisons (P < 0.017). The mean T2 values between fat‐suppressed T2‐SI and fat‐suppressed T2‐IS did not differ significantly in any region (P = 0.077–0.873). However, the mean T2 values of conventional T2‐SI were significantly lower compared with conventional T2‐IS in three of the regions (P < 0.05). The intraclass correlation coefficient (ICC) between the two fat‐suppressed T2 maps was higher than the ICC between the two conventional T2 maps (0.276–0.800 vs. –0.032–0.455) for three regions.

Conclusion

Compared with conventional T2 mapping, fat‐suppressed T2 mapping provides lower T2 values of the articular cartilage and more reproducible results for the porcine knee joint.

Level of Evidence: 2

J. Magn. Reson. Imaging 2017;45:1076–1081
Diagnostic accuracy of intracellular uptake rates calculated using dynamic Gd‐EOB‐DTPA‐enhanced MRI for hepatic fibrosis stage
Authors: Juluru Krishna , Talal Andrew H. , Yantiss Rhonda K. , Spincemaille Pascal , Weidman Elizabeth K. , Giambrone Ashley E. , Jalili Sadaf , Sourbron Steven P. , Dyke Jonathan P.
Published: August 2016

Purpose

To assess the diagnostic accuracy of intracellular uptake rates (Ki), and other quantitative pharmacokinetic (PK) parameters, for hepatic fibrosis stage; to compare this accuracy with a previously published semiquantitative metric, contrast enhancement index (CEI); and to assess variability of these parameters between liver regions.

Materials and Methods

This was a case–control study design. Dynamic Gd‐EOB‐DTPA‐enhanced 1.5T magnetic resonance imaging (MRI) was performed prospectively in 22 subjects with varying known stages of hepatic fibrosis. PK parameters and CEI were derived from the whole livers and from three fixed regions of interest (ROIs) in all subjects. Spearman rank correlation coefficients were computed to assess the relationship between fibrosis stages and each parameter. Receiver operating characteristic (ROC) curves were constructed to discriminate severe fibrosis (stages 3–4) from nonsevere fibrosis (stages 0–2). The coefficient of variation (CV) was calculated to assess variability in parameters between ROIs.

Results

Ki and fibrosis stage were significantly correlated (R = –0.55, 95% confidence interval [CI] [–0.79, –0.14], P = 0.01). Area under ROC curve (AUC) in distinguishing severe from nonsevere fibrosis for Ki was 0.84 (95% CI [0.65,1.00]), and for CEI was 0.64 (95% CI [0.39, 0.89]) (P = 0.0248). CV for Ki and CEI were 33.4 and 5.8, respectively. The only other parameter in the PK model having significant correlation with fibrosis stage was absolute arterial blood flow (Fa) (R = –0.48, 95% CI [−0.75,−0.05], P = 0.03).

Conclusion

Hepatocyte intracellular uptake rate, Ki, derived from dynamic contrast‐enhanced MRI, correlates with fibrosis stage and may contribute to a noninvasive biomarker of hepatic fibrosis.

Level of Evidence: 2

J. Magn. Reson. Imaging 2017;45:1177–1185
CMC hypersurfaces with canonical principal direction in space forms
Authors: Di Scala A. J. , Ruiz‐Hernández G.
Published: August 2016

A hypersurface of the space form has a canonical principal direction (CPD) relative to the closed and conformal vector field Z of if the projection of Z to M is a principal direction of M. We show that CPD hypersurfaces with constant mean curvature are foliated by isoparametric hypersurfaces. In particular, we show that a CPD surface with constant mean curvature of space form is invariant by the flow of a Killing vector field whose action is polar on . As consequence we show that a compact CPD minimal surface of the sphere is a Clifford torus. Finally, we consider the case when a CPD Euclidean hypersurface has zero Gauss–Kronecker curvature.
High phenolics Rutgers Scarlet Lettuce improves glucose metabolism in high fat diet‐induced obese mice
Authors: Cheng Diana M. , Roopchand Diana E. , Poulev Alexander , Kuhn Peter , Armas Isabel , Johnson William D. , Oren Andrew , Ribnicky David , Zelzion Ehud , Bhattacharya Debashish , Raskin Ilya
Published: August 2016

Scope

The ability of high phenolic Rutgers Scarlet Lettuce (RSL) to attenuate metabolic syndrome and gut dysbiosis was studied in very high fat diet (VHFD)‐fed mice. Phenolic absorption was assessed in vivo and in a gastrointestinal tract model.

Methods and results

Mice were fed VHFD, VHFD supplemented with RSL (RSL‐VHFD) or store‐purchased green lettuce (GL‐VHFD), or low‐fat diet (LFD) for 13 weeks. Compared to VHFD or GL‐VHFD‐fed groups, RSL‐VHFD group showed significantly improved oral glucose tolerance (p<0.05). Comparison of VHFD, RSL‐VHFD, and GL‐VHFD groups revealed no significant differences with respect to insulin tolerance, hepatic lipids, body weight gain, fat mass, plasma glucose, triglycerides, free fatty acid, and lipopolysaccharide levels, as well as relative abundances of major bacterial phyla from 16S rDNA amplicon data sequences (from fecal and cecal samples). However, RSL and GL‐supplementation increased abundance of several taxa involved in plant polysaccharide degradation/fermentation. RSL phenolics chlorogenic acid, quercetin‐3‐glucoside, and quercetin‐malonyl‐glucoside were bioaccessible in the TIM‐1 digestion model, but had relatively low recovery.

Conclusions

RSL phenolics contributed to attenuation of post‐prandial hyperglycemia. Changes in gut microbiota were likely due to microbiota accessible carbohydrates in RSL and GL rather than RSL phenolics, which may be metabolized, absorbed, or degraded before reaching the colon.
Characterizing brain tissue by assessment of the distribution of anisotropic microstructural environments in diffusion‐compartment imaging (DIAMOND)
Authors: Scherrer Benoit , Schwartzman Armin , Taquet Maxime , Sahin Mustafa , Prabhu Sanjay P. , Warfield Simon K.
Published: August 2016

Purpose

To develop a statistical model for the tridimensional diffusion MRI signal at each voxel that describes the signal arising from each tissue compartment in each voxel.

Theory and Methods

In prior work, a statistical model of the apparent diffusion coefficient was shown to well‐characterize the diffusivity and heterogeneity of the mono‐directional diffusion MRI signal. However, this model was unable to characterize the three‐dimensional anisotropic diffusion observed in the brain. We introduce a new model that extends the statistical distribution representation to be fully tridimensional, in which apparent diffusion coefficients are extended to be diffusion tensors. The set of compartments present at a voxel is modeled by a finite sum of unimodal continuous distributions of diffusion tensors. Each distribution provides measures of each compartment microstructural diffusivity and heterogeneity.

Results

The ability to estimate the tridimensional diffusivity and heterogeneity of multiple fascicles and of free diffusion is demonstrated.

Conclusion

Our novel tissue model allows for the characterization of the intra‐voxel orientational heterogeneity, a prerequisite for accurate tractography while also characterizing the overall tridimensional diffusivity and heterogeneity of each tissue compartment. The model parameters can be estimated from short duration acquisitions. The diffusivity and heterogeneity microstructural parameters may provide novel indicator of the presence of disease or injury. Magn Reson Med 76:963–977, 2016. © 2015 Wiley Periodicals, Inc.
Weighted norms in subspace‐based methods for time series analysis
Authors: Gillard J. W. , Zhigljavsky A. A.
Published: August 2016

Many modern approaches of time series analysis belong to the class of methods based on approximating high‐dimensional spaces by low‐dimensional subspaces. A typical method would embed a given time series into a structured matrix and find a low‐dimensional approximation to this structured matrix. The purpose of this paper is twofold: (i) to establish a correspondence between a class of SVD‐compatible matrix norms on the space of Hankel matrices and weighted vector norms (and provide methods to construct this correspondence) and (ii) to motivate the importance of this for problems in time series analysis. Examples are provided to demonstrate the merits of judiciously selecting weights on imputing missing data and forecasting in time series. Copyright © 2016 John Wiley & Sons, Ltd.
The effect of radiation exposure on the mechanical behavior of Rohacell foams used in composite structures
Authors: Zaldivar R. J. , Patel D. N. , Labatete‐Goeppinger A. , Nokes J. P.
Published: August 2016

Rohacell foam is being utilized on a number of composite structures used for space applications. The effect of radiation exposure on these materials has been evaluated to determine the degree of structural degradation that may occur in a space environment. A 60Co source was used on Rohacell 31HFHT, Rohacell 110WF, and Rohacell HERO 110. The exposure levels varied from 0 to 15 Mrad, in both an inert and an air environment. Tensile tests were then performed to determine the failure strength and strain. Mechanical testing of the 31HFHT specimens showed a significant decrease in strength of 50% after only a 4‐Mrad exposure. The failure strain also exhibited a 75% decrease over the same range. The 15‐Mrad specimens continued to decrease in strength, losing 95% of the initial strength. The rate of tensile strength degradation with radiation increased as the foam cell pore diameter increased. Dynamic mechanical analysis indicated an increase in the peak intensity of the tan delta curve as a function of radiation exposure, which has been attributed to radiation‐induced polymer chain fragmentation. The fracture behavior of the radiated specimens also exhibited embrittlement of the polymer cells consistent with the mechanical properties. Thermal gravimetric analysis showed a decrease in the temperature for the onset of mass loss with radiation exposure, which is consistent with chain scission of the polymer network. Even though the chemical structure of all polymethacrylimide foams is susceptible to radiation degradation, a smaller foam cell pore diameter may provide additional margin with respect to the rate of mechanical property degradation. POLYM. COMPOS., 39:2181–2189, 2018. © 2016 Society of Plastics Engineers
Confounding of the association between statins and Parkinson disease: systematic review and meta‐analysis
Authors: Bykov Katsiaryna , Yoshida Kazuki , Weisskopf Marc G. , Gagne Joshua J.
Published: August 2016

Purpose

Both statins and higher serum cholesterol have been reported to reduce to risk of Parkinson Disease (PD). Given the importance of adjusting for cholesterol levels when evaluating the effect of statins, we assessed whether the protective effect of statins would remain when adjustment for cholesterol is performed.

Methods

We conducted a systematic review of epidemiologic studies that reported quantitative estimates of the association between statins and incident PD and were published through February 2016. Random‐effects meta‐analysis was used to assess the effect of statins on PD separately among the studies that adjusted for either cholesterol or hyperlipidemia and studies that did not.

Results

Ten eligible studies that evaluated the use of statins and incident PD were identified. Among the six studies that did not adjust for cholesterol, a protective effect of statins was observed (relative risk 0.75; 95% confidence intervals (CI) 0.60 to 0.92). Excluding studies with possible bias because of reverse causation or stratifying on study design did not affect the results. No protective effect was observed among the four studies that adjusted for either cholesterol of hyperlipidemia (relative risk 0.91; 95%CI 0.68 to 1.22). The effect estimate for studies that adjusted for cholesterol was 1.04 (95%CI 0.68 to 1.59) when a study with immortal time bias was excluded.

Conclusions

The apparent protective effect of statins on risk of PD is at least partially explained by confounding by statin indication. Immortal time bias and healthy user effects also could have contributed to biased results. Copyright © 2016 John Wiley & Sons, Ltd.
How valid are IMS DA summary statistics of children's vaccination status?
Authors: El‐Turki Aisha , Long Paul , Wong Ian CK , Smith Helen
Published: August 2016

Purpose

Accurate recording of immunization status is essential for the evaluation of any immunization programme. In September 2006, 7‐valent pneumococcal conjugate vaccination (PCV7) was introduced into the UK's routine childhood immunization programme. This study validated the PCV7 immunization status of children aged 2 years recorded in the IMS Disease Analyses (DA) database.

Methods

The PCV7 vaccination uptake rate for children born in 2008 in the IMS DA database was calculated. A sample of 173 of the 2497 children not recorded as vaccinated was identified, and a questionnaire was sent to each of their general practitioners to ascertain the child's true PCV7 vaccination status.

Results

In the IMS DA data of 15 237 children born in 2008, 12 740 (83.6%) had a vaccination record of PCV7. One‐hundred and eleven of the 167 questionnaires sent to the child's general practitioners were returned, giving an adjusted response rate of 111/167 (66.5%). Based on the general practitioners' responses, 71 (64%) of these children were fully vaccinated according to their general practitioner's records making the revised estimated vaccination rate for this cohort 94.1%

Conclusion

This validation study has shown that caution is needed if using historical IMS patient‐level data to analyse the effectiveness of PCV7 as there is a potential under‐recording of immunization leading to under representation of vaccination rates by approximately 10%. Copyright © 2016 John Wiley & Sons, Ltd.
Relative Risks for Lethal Prostate Cancer Based on Complete Family History of Prostate Cancer Death
Authors: Albright Frederick S. , Stephenson Robert A. , Agarwal Neeraj , Cannon‐Albright Lisa A.
Published: August 2016

BACKGROUND

There are few published familial relative risks (RR) for lethal prostate cancer. This study estimates RRs for lethal prostate cancer based on comprehensive family history data, with the goal of improving identification of those men at highest risk of dying from prostate cancer.

METHODS

We used a population‐based genealogical resource linked to a statewide electronic SEER cancer registry and death certificates to estimate relative risks (RR) for death from prostate cancer based upon family history. Over 600,000 male probands were analyzed, representing a variety of family history constellations of lethal prostate cancer. RR estimates were based on the ratio of the observed to the expected number of lethal prostate cancer cases using internal rates.

RESULTS

RRs for lethal prostate cancer based on the number of affected first‐degree relatives (FDR) ranged from 2.49 (95% CI: 2.27, 2.73) for exactly 1 FDR to 5.30 (2.13, 10.93) for ≥3 affected FDRs. In an absence of affected FDRs, increased risk was also significant for increasing numbers of affected second‐degree or third degree relatives. Equivalent risks were observed for similar maternal and paternal family history.

CONCLUSIONS

This study provides population‐based estimates of lethal prostate cancer risk based on lethal prostate cancer family history. Many family history constellations associated with two to greater than five times increased risk for lethal prostate cancer were identified. These lethal prostate cancer risk estimates hold potential for use in identification, screening, early diagnosis, and treatment of men at high risk for death from prostate cancer. Prostate77:41–48, 2017. © 2016 Wiley Periodicals, Inc.
Critical comparison of mass analyzers for forensic hair analysis by ambient ionization mass spectrometry
Authors: Duvivier Wilco F. , van Beek Teris A. , Nielen Michel W. F.
Published: August 2016

Rationale

Recently, several direct and/or ambient mass spectrometry (MS) approaches have been suggested for drugs of abuse imaging in hair. The use of mass spectrometers with insufficient selectivity could result in false‐positive measurements due to isobaric interferences. Different mass analyzers have been evaluated regarding their selectivity and sensitivity for the detection of Δ9‐tetrahydrocannabinol (THC) from intact hair samples using direct analysis in real time (DART) ionization.

Methods

Four different mass analyzers, namely (1) an orbitrap, (2) a quadrupole orbitrap, (3) a triple quadrupole, and (4) a quadrupole time‐of‐flight (QTOF), were evaluated. Selectivity and sensitivity were assessed by analyzing secondary THC standard dilutions on stainless steel mesh screens and blank hair samples, and by the analysis of authentic cannabis user hair samples. Additionally, separation of isobaric ions by use of travelling wave ion mobility (TWIM) was investigated.

Results

The use of a triple quadrupole instrument resulted in the highest sensitivity; however, transitions used for multiple reaction monitoring were only found to be specific when using high mass resolution product ion measurements. A mass resolution of at least 30,000 FWHM at m/z 315 was necessary to avoid overlap of THC with isobaric ions originating from the hair matrix. Even though selectivity was enhanced by use of TWIM, the QTOF instrument in resolution mode could not indisputably differentiate THC from endogenous isobaric ions in drug user hair samples.

Conclusions

Only the high resolution of the (quadrupole) orbitrap instruments and the QTOF instrument in high‐resolution mode distinguished THC in hair samples from endogenous isobaric interferences. As expected, enhanced selectivity compromises sensitivity and THC was only detectable in hair from heavy users. Copyright © 2016 John Wiley & Sons, Ltd.
Instrumental variable analysis of multiplicative models with potentially invalid instruments
Authors: Shardell Michelle , Ferrucci Luigi
Published: August 2016

Instrumental variable (IV) methods have potential to consistently estimate the causal effect of an exposure on an outcome in the presence of unmeasured confounding. However, validity of IV methods relies on strong assumptions, some of which cannot be conclusively verified from observational data. One such assumption is that the effect of the proposed instrument on the outcome is completely mediated by the exposure. We consider the situation where this assumption is violated, but the remaining IV assumptions hold; that is, the proposed IV (1) is associated with the exposure and (2) has no unmeasured causes in common with the outcome. We propose a method to estimate multiplicative structural mean models of binary outcomes in this scenario in the presence of unmeasured confounding. We also extend the method to address multiple scenarios, including mediation analysis. The method adapts the asymptotically efficient G‐estimation approach that was previously proposed for additive structural mean models, and it can be carried out using off‐the‐shelf software for generalized method of moments. Monte Carlo simulation studies show that the method has low bias and accurate coverage. We applied the method to a case study of circulating vitamin D and depressive symptoms using season of blood collection as a (potentially invalid) instrumental variable. Potential applications of the proposed method include randomized intervention studies as well as Mendelian randomization studies with genetic variants that affect multiple phenotypes, possibly including the outcome. Published 2016. This article is a U.S. Government work and is in the public domain in the USA
Contract ineffectiveness in emerging markets: An institutional theory perspective⋆
Authors: Shou Zhigang , Zheng Xu (Vivian) , Zhu Wenting
Published: August 2016

The effectiveness of contracts is bounded by the institutional environment in which they are designed and enforced. When firms form supply chain partnerships in emerging markets, they may experiencecontract ineffectiveness, which is defined as a firm's perceived limits of contracts with respect to safeguarding interests and coordinating activities. Specifically, we identify two institutional factors that may give rise to contract ineffectiveness, information transparency and legal enforceability, as they determine how effectively a firm designs and enforces a contract. In addition, we reveal that contract ineffectiveness prompts a firm to seek social ties, including business ties and political ties, to overcome the institutionally induced limits of contracts. These efforts, however, are moderated by the type of predominant pressure a firm bears. While equity pressure strengthens the relationship between contract ineffectiveness and a firm's pursuit of social ties, efficiency pressure weakens this relationship, because seeking social ties imposes an extra burden of efficiency. Tested by data collected from 187 distributors in China, our study reveals the institutional causes and the consequences of contract ineffectiveness, which is a common problem encountered by firms when forming supply chain partnerships in emerging markets.
Evolución de la evaluación del desempeño docente en la Facultad de Medicina; evidencia de validez y confiabilidad
Authors: Flores Hernández Fernando , Gatica Lara Florina , Sánchez-Mendiola Melchor , Martínez González Adrián
Published: August 2016

Introducción: Existen diversos modelos encaminados a evaluar el desempeño docente, los cuales consideran a la docencia como un proyecto institucional dirigido a elevar la calidad de la educación.
Objetivo: Se analizó la evolución y la transición de los distintos instrumentos asociados al proceso de evaluación del desempeño docente en la Facultad de Medicina de la UNAM en términos de su contenido y la evidencia de validez y confiabilidad de los mismos.
Método: El estudio tuvo un carácter analítico, longitudinal, retrospectivo, en el cual se analizaron los instrumentos METEBQ-B, COED, y OPINEST en tres fases; a) contraste de estructura y contenido; b) contraste de valores psicométricos y c) contraste de las dimensiones con las tendencias y modelos predominantes vigentes.
Resultados: Los instrumentos tuvieron una escala tipo Likert, con una confiabilidad superior a 0.95, con una varianza explicada superior al 50% y una extensión variable de 24 a 44 ítems. En contenido los instrumentos migraron de una evaluación centrada en valorar la satisfacción de los estudiantes, a una evaluación de las competencias docentes. En relación con las dimensiones el OPINEST fue congruente con los referentes nacionales e internacionales. 
Discusión y conclusión: La evaluación del desempeño docente es uno de los pilares que pueden sustentar la calidad del sistema educativo, en este sentido destacó el aporte del Departamento de Evaluación Educativa de la Secretaría de Educación Médica de la Facultad de Medicina de la UNAM, que contribuyó al desarrollo de los diversos instrumentos, los mismos que en su conjunto consideraron los criterios generales que denotan la evidencia que sustenta las fuentes necesarias de validez y confiabilidad para su aplicación.
Premorbid cannabis use is associated with more symptoms and poorer functioning in schizophrenia spectrum disorder
Authors: Ringen P. A. , Nesvåg R. , Helle S. , Lagerberg T. V. , Lange E. H. , Løberg E. M. , Agartz I. , Andreassen O. A. , Melle I.
Published: August 2016

Background

Cannabis use disorder is associated with an earlier age at onset and a more severe outcome of schizophrenia spectrum disorders. The role of cannabis use before the onset of illness (premorbid cannabis use) has not been fully investigated. We here examined how amount and type of premorbid cannabis use was associated with the later course of illness including current substance use, symptoms and level of functioning in schizophrenia spectrum disorder.

Method

We used a naturalistic sample of patients with DSM-IV schizophrenia spectrum disorders with a comprehensive history of illness and substance use. Data on premorbid substance use was obtained from comprehensive self-report. The relationship to outcome was investigated using regression models that included current substance use and premorbid functioning.

Results

Pre-schizophrenia cannabis use was significantly associated with more severe psychotic symptoms and impaired functioning. Higher levels of premorbid cannabis use were associated with higher levels of current psychotic symptoms. These associations were independent of current substance use and premorbid functioning. Early use of cannabis (age <17 years) was associated with earlier age at onset of psychosis, independently of potential confounders.

Conclusions

Pre-psychosis cannabis use affects illness outcome in schizophrenia spectrum disorders, and is associated with lower age at onset of psychosis. These findings of independent negative effects of premorbid cannabis use in schizophrenia suggest that a limitation of the general use of cannabis may have beneficial health effects.
German Gymnastics, Modern German Dance, and Nazi Aesthetics
Authors: Kant Marion
Published: August 2016

At the beginning of the nineteenth century, when Napoleon's French empire conquered much of Europe, the German patriot Friedrich Ludwig Jahn invented the first German national gymnastics program known as Turnen. The idea was to create a new German body and a new form of national discipline. Walking for bodily fitness, to instill national awareness, training on special equipment and rediscovering ancient German dance forms all became part of the new body culture. It is out of this movement with its nationalist and later racist culture that much of the modern gymnastics and dance movements in Germany gained their ideologies. This article sketches some stages of this social and physical continuity, from the resistance to the French to the establishment of the racial state in 1933 and to the provision of a Nazi aesthetic by German modern dancers.
To Be Continued: An Exchange on Tiffany Barber's “Ghostcatching and After Ghostcatching, Dances in the Dark”
Authors: Nicifero Alessandra
Published: August 2016

This is a brief introduction to a conversation about dance, race, and technology indirectly initiated by one of Bill T. Jones's blog entries on the New York Live Arts website after reading Tiffany Barber's article “Ghostcatching and After Ghostcatching, Dances in the Dark” in the April 2015 DRJ issue. Paul Kaiser of the Open Ended Group and cocreator with Bill T. Jones of Ghostcatching wrote a letter to the editor followed by Barber's response.
L'évolution des terrains incultes en Belgique
Authors: Clicheroux Emile
Published: August 2016

Dans un précédent article, nous avons étudié l'évolution de la forêt en Belgique et nous sommes arrivé à la conclusion que la transformation de la forêt était intimement liée à la mise en valeur des terrains incultes.

Nous étudierons dans les pages qui vont suivre l'évolution de l'étendue des terrains incultes en Belgique.

Par terrains incultes, il faut entendre les étendues couvertes de bruyères, les sarts, les broussailles non exploitées, les étendues marécageuses ou rocailleuses, les landes, les fagnes, les dunes ne portant pas de culture, en un mot tout terrain qui n'est employé régulièrement à aucun usage agricole ou forestier.
EDITORIAL
Authors: BURDEN MICHAEL
Published: August 2016

One of the first occasions I saw an opera lit (or partially lit) with candles was a staging of Rameau's Castor et Pollux at the Estates Theatre in Prague. Despite many imperfections, the effect – pardon the upcoming pun – was electric: the upward throw of light from the footlights, the sideways throw of light from the torchères and the variety of shadows created in the upper area of the proscenium were a revelation. Until recently, an often-given solution to historical theatre lighting was to invoke the Drottningholm candle (and related technologies), a device with a synthetic flame that hovers according to the heat generated by the light source, used at the baroque theatre outside Stockholm.
Béla Bartók's Evolutionary Model of Folk Music
Authors: BENNETT JAMES
Published: August 2016

In his ethnomusicological writings and lectures, Béla Bartók describes folk music as ‘a natural product, just like the various forms of animal and vegetable life’ and elaborates this view, going on to describe a collection of developmental processes modelled explicitly on biological evolution. In this article, I characterize Bartók's evolutionary model by laying bare the taxonomies and genealogies inherent in his classificatory system. Then, through an analysis of the fifth of hisEight Improvisations on Hungarian Folk Songs(1920), I suggest the outlines of a method for interpreting and analysing Bartók's music engendered from this evolutionary model, a method that involves the elaboration of two ideas: (1) a conceptual shift from a relatively historically static major/minor tonality to a multivalent, ‘evolving’ tonality, and (2) the reconception of motives or themes as having no single original forms, but rather as being related genetically, as somehow evolving in their own right.
The Great War: World war, total war
Authors: Becker Annette
Published: August 2016

The Great War was globalized and totalized1 by the inclusion of colonial and newly independent people from all over the world and of civilians, old people, women and children. The European war became a laboratory for all the suffering of the century, from the extermination of the Armenians to the refugee crisis, the internments, and the unending modernization of warfare.
L'évolution économique de l'industrie. charbonnière belge depuis 1831
Authors: Wibail Amé
Published: August 2016

Dans une précédente étude relative á l’évolution de la sidérurgie belge, nous avons relevé, grâce aux séries statistiques que nous avons pu composer, des mouvements divers dans certains phénomènes économiques tels que la production, la productivité, le commerce et les prix. Outre les cycles économiques, nous avons pu constater qu’il existait des oscillations de longue durée nettement caractérisées. L’étude d’une seule industrie ne permettait cependant pas d’établir des relations ou des conclu-sions générates, mais elle est d’une grande utilité comme point de départ pour l’étude d’autres industries; cela est d’autant plus vrai pour la sidérurgie, qui se caractérise par une sensibilité assez marquée aux mouvements de la conjoncture. Il est tout indiqué pour l’étude de notre économie d'analyser ensuite 1’évolution de l’industrie charbonnière ; il s'agit, en effet, ici encore, d'une industrie de base de notre pays, moins ancienne peut-être mais beaucoup plus importante. D'autre part, les relevés statistiques, assez complets, etablis par l'Administration des Mines, nous fourniront les éléments nécessaires à cette étude.
Des rythmes séculaires d’expansion des industries houillères européennes dans leurs rapports avec les prix et les coûts de production
Authors: Saudée Edouard de Bivort de La
Published: August 2016

Avant la guerre de 1914, quatre principaux pays producteurs se partageaient le marché charbonnier européen: le Royaume-Uni, l’Allemagne, la France et la Belgique, suivant leur ordre d’importance.

La position centrale que ces pays occupent en Europe, des frontières communes, des voies de communication courtes et rapides, enfin la pratique d’une politique commerciale encore largement libre-échangiste, maintenaient les industries houillères respectives de ces pays dans une très grande interdépendance les unes vis-à-vis des autres. L’expansion de ces industries s’est néanmoins faite suivant des rythmes différents.

L’analyse comparative de ces rythmes séculaires et de longue durée sur le plan national et international fait l’objet de cette étude.

Sur le plan international on comparera directement les rythmes d’expansion respectifs. Pour chaque pays, on cherchera à établir l’expansion différentielle de l’industrie houillère par rapport au développement industriel général.
Elterliche Belastung und die Zuverlässigkeit von Elternangaben in der Diagnostik psychisch und verhaltensauffälliger Kinder und Jugendlicher
Authors: Irlbauer-Müller Viktoria , Eichler Anna , Stemmler Mark , Moll Gunther H. , Kratz Oliver
Published: August 2016

Zusammenfassung. Fragestellung: Elternangaben werden regelhaft in die Diagnostik psychisch und verhaltensauffälliger Kinder und Jugendlicher einbezogen. Ihre Zuverlässigkeit steht jedoch aufgrund von Belastungen der Eltern und einer so verzerrten Wahrnehmung der kindseitigen Symptomatik infrage. Methodik: Für N = 68 zu einem kinder- und jugendpsychiatrischen/-psychotherapeutischen Erstkontakt vorstellige Kinder und Jugendliche (Alter: 11–18 Jahre) wurden je ein Eltern- und ein klinisches Urteil erhoben (internalisierende, externalisierende Auffälligkeiten, Gesamtproblemwert). Zusätzlich wurde die elterliche Belastung mittels des Eltern-Belastungs-Inventars (EBI, Tröster, 2011) erfasst (kind- und elternbezogene Belastung, Gesamtbelastungswert). Ergebnisse: Für auffällig belastete Eltern fanden sich in Mittelwertvergleichen größere Differenzen aus Eltern- und klinischem Urteil als für unauffällig belastete Eltern. Korrelationen zeigten zudem, dass eine höhere elterliche Belastung mit größeren Urteilsdifferenzen einhergeht. Die multiple Regression belegte dabei die Vorhersagekraft kindbezogener elterlicher Belastung für die Urteilsdifferenz. Genannte Ergebnisse gelten für internalisierende und externalisierende Auffälligkeiten sowie für den Gesamtproblemwert. Schlussfolgerungen: Elterliche Belastung sollte systematisch erfasst werden, um Elternangaben kritischer zu reflektieren und deren Einbezug in diagnostische und therapeutische Entscheidungen sorgfältiger abzuwägen.
MAVS maintains mitochondrial homeostasis via autophagy
Authors: Sun Xiaofeng , Sun Liwei , Zhao Yuanyuan , Li Ying , Lin Wei , Chen Dahua , Sun Qinmiao
Published: August 2016

Mitochondrial antiviral signalling protein (MAVS) acts as a critical adaptor protein to transduce antiviral signalling by physically interacting with activated RIG-I and MDA5 receptors. MAVS executes its functions at the outer membrane of mitochondria to regulate downstream antiviral signalling, indicating that the mitochondria provides a functional platform for innate antiviral signalling transduction. However, little is known about whether and how MAVS-mediated antiviral signalling contributes to mitochondrial homeostasis. Here we show that the activation of MAVS is sufficient to induce autophagic signalling, which may mediate the turnover of the damaged mitochondria. Importantly, we find MAVS directly interacts with LC3 through its LC3-binding motif ‘YxxI’, suggesting that MAVS might act as an autophagy receptor to mediate mitochondrial turnover upon excessive activation of RLR signalling. Furthermore, we provide evidence that both MAVS self-aggregation and its interaction with TRAF2/6 proteins are important for MAVS-mediated mitochondrial turnover. Collectively, our findings suggest that MAVS acts as a potential receptor for mitochondria-associated autophagic signalling to maintain mitochondrial homeostasis.
In situ high-resolution structure of the baseplate antenna complex in Chlorobaculum tepidum
Authors: Nielsen Jakob Toudahl , Kulminskaya Natalia V. , Bjerring Morten , Linnanto Juha M. , Rätsep Margus , Pedersen Marie Østergaard , Lambrev Petar H. , Dorogi Márta , Garab Győző , Thomsen Karen , Jegerschöld Caroline , Frigaard Niels-Ulrik , Lindahl Martin , Nielsen Niels Chr.
Published: August 2016

Photosynthetic antenna systems enable organisms harvesting light and transfer the energy to the photosynthetic reaction centre, where the conversion to chemical energy takes place. One of the most complex antenna systems, the chlorosome, found in the photosynthetic green sulfur bacterium Chlorobaculum (Cba.) tepidum contains a baseplate, which is a scaffolding super-structure, formed by the protein CsmA and bacteriochlorophyll a. Here we present the first high-resolution structure of the CsmA baseplate using intact fully functional, light-harvesting organelles from Cba. tepidum, following a hybrid approach combining five complementary methods: solid-state NMR spectroscopy, cryo-electron microscopy, isotropic and anisotropic circular dichroism and linear dichroism. The structure calculation was facilitated through development of new software, GASyCS for efficient geometry optimization of highly symmetric oligomeric structures. We show that the baseplate is composed of rods of repeated dimers of the strongly amphipathic CsmA with pigments sandwiched within the dimer at the hydrophobic side of the helix.
Role of peripheral blood minimum residual disease at day 8 of induction therapy in high-risk pediatric patients with acute lymphocytic leukemia
Authors: Salina Thais Ditolvo da Costa , Ferreira Yvelise Antunes , Alves Eliana Brasil , Ferreira Cristina Motta , De Paula Erich Vinícius , Mira Marcelo Távora , Passos Leny da Mota
Published: August 2016

Risk stratification and treatment intensification, based on minimal residual disease (MRD) mensurement, changed the prognosis of pediatric patients with acute lymphocytic leukemia (ALL). The main aim of this study was to investigate whether peripheral blood (PB) MRD measurement at day 8 (D8) could predict the risk stratification category determined by bone marrow (BM) MRD at day 15 (D15). The study was performed prospectively, in a cohort of 40 children with B-lineage ALL, adopting the protocol of the Brazilian Cooperative Group of the Treatment Childhood Leukemia (GBTLI-2009). MRD was detected by flow cytometry (FC) using a simplifed panel that can reliably identify MRD at early phases of induction therapy. Upon diagnosis, the proportion of low and high-risk patients, was 24:16 (60%:40%). The main result of our study demonstrated the potential of D8 MRD in anticipating of week the risk stratification of high-risk patients as determined by D15 BM MRD. In these patients D8 MRD level of 1% was able to segregate high risk fast responders from high risk slow responders (p = 0.0097). This result could represent an opportunity for early treatment intensification, as already performed in some protocols.
Spatiotemporal structure of intracranial electric fields induced by transcranial electric stimulation in humans and nonhuman primates
Authors: Opitz Alexander , Falchier Arnaud , Yan Chao-Gan , Yeagle Erin M. , Linn Gary S. , Megevand Pierre , Thielscher Axel , Deborah A. Ross , Milham Michael P. , Mehta Ashesh D. , Schroeder Charles E.
Published: August 2016

Transcranial electric stimulation (TES) is an emerging technique, developed to non-invasively modulate brain function. However, the spatiotemporal distribution of the intracranial electric fields induced by TES remains poorly understood. In particular, it is unclear how much current actually reaches the brain, and how it distributes across the brain. Lack of this basic information precludes a firm mechanistic understanding of TES effects. In this study we directly measure the spatial and temporal characteristics of the electric field generated by TES using stereotactic EEG (s-EEG) electrode arrays implanted in cebus monkeys and surgical epilepsy patients. We found a small frequency dependent decrease (10%) in magnitudes of TES induced potentials and negligible phase shifts over space. Electric field strengths were strongest in superficial brain regions with maximum values of about 0.5 mV/mm. Our results provide crucial information of the underlying biophysics in TES applications in humans and the optimization and design of TES stimulation protocols. In addition, our findings have broad implications concerning electric field propagation in non-invasive recording techniques such as EEG/MEG.