A generalization of moderated statistics to data adaptive semiparametric estimation in high-dimensional biology

The widespread availability of high-dimensional biological data has made the simultaneous screening of numerous biological characteristics a central statistical problem in computational biology. While the dimensionality of such datasets continues to increase, the problem of teasing out the effects of biomarkers in studies measuring baseline confounders while avoiding model misspecification remains only partially addressed. Efficient estimators constructed from data adaptive estimates of the data-generating distribution provide an avenue for avoiding model misspecification; however, in the context of high-dimensional problems requiring simultaneous estimation of numerous parameters, standard variance estimators have proven unstable, resulting in unreliable Type-I error control under standard multiple testing corrections. We present the formulation of a general approach for applying empirical Bayes shrinkage approaches to asymptotically linear estimators of parameters defined in the nonparametric model. The proposal applies existing shrinkage estimators to the estimated variance of the influence function, allowing for increased inferential stability in high-dimensional settings. A methodology for nonparametric variable importance analysis for use with high-dimensional biological datasets with modest sample sizes is introduced and the proposed technique is demonstrated to be robust in small samples even when relying on data adaptive estimators that eschew parametric forms. Use of the proposed variance moderation strategy in constructing stabilized variable importance measures of biomarkers is demonstrated by application to an observational study of occupational exposure. The result is a data adaptive approach for robustly uncovering stable associations in high-dimensional data with limited sample sizes

Development of constitutive model for precast prestressed concrete segmental columns

The interest of using precast segmental columns in construction of concrete bridges has significantly increased in recent years. One research area of concrete bridges is the application of Precast Prestressed Concrete Segmental (PPCS) Column in any structural analysis software or FE program code. Modeling a PPCS column, which consists of various materials with interaction between them, is complicated and time-consuming. This research attempts to formulate the stiffness matrix of PPCS columns in order to form the constitutive model in linear form to evaluate the response of the columns. A two-dimensional finite element model is presented in the finite element package ANSYS. Parametric studies are conducted by finite element models to verify the constitutive models for the PPCS column with a different number of concrete segments. Comparison between the constitutive model and the FE program results indicates that the constitutive model is accurate enough to predict the deformation of the PPCS columns

Benefits of greenhouse gas mitigation on the supply, management, and use of water resources in the United States

Climate change impacts on water resources in the United States are likely to be far-reaching and substantial because the water is integral to climate, and the water sector spans many parts of the economy. This paper estimates impacts and damages from five water resource-related models addressing runoff, drought risk, economics of water supply/demand, water stress, and flooding damages. The models differ in the water system assessed, spatial scale, and unit of assessment, but together provide a quantitative and descriptive richness in characterizing water sector effects that no single model can capture. The results, driven by a consistent set of greenhouse gas (GHG) emission and climate scenarios, examine uncertainty from emissions, climate sensitivity, and climate model selection. While calculating the net impact of climate change on the water sector as a whole may be impractical, broad conclusions can be drawn regarding patterns of change and benefits of GHG mitigation. Four key findings emerge: 1) GHG mitigation substantially reduces hydro-climatic impacts on the water sector; 2) GHG mitigation provides substantial national economic benefits in water resources related sectors; 3) the models show a strong signal of wetting for the Eastern US and a strong signal of drying in the Southwest; and 4) unmanaged hydrologic systems impacts show strong correlation with the change in magnitude and direction of precipitation and temperature from climate models, but managed water resource systems and regional economic systems show lower correlation with changes in climate variables due to non-linearities created by water infrastructure and the socio-economic changes in non-climate driven water demand

Comparison of long-pulsed alexandrite laser and topical tretinoin-ammonium lactate in axillary acanthosis nigricans: A case series of patients in a before-after trial

Background: Acanthosis nigricans (AN) is a brown to black, velvety hyperpigmentation of the skin that usually involves cutaneous folds. Treatment of AN is important regarding cosmetic reasons and various therapeutic modalities have been used for these purposes. The goal of this study was to compare the effectiveness of long-pulsed alexandrite laser and topical tretinoin-ammonium lactate for treatment of axillary-AN. Methods: Fifteen patients with bilateral axillary-AN were studied in Razi Hospital, Tehran, Iran. Diagnosis was confirmed by two independent dermatologists. Each side skin lesion was randomly allocated to either topical mixed cream of tretinoin 0.05- ammonium lactate 12 or long-pulsed alexandrite laser. Duration of treatment was 14 weeks. At endpoint, the mean percent reduction from baseline in pigmentation area was compared between the two groups. Results: The study population consisted of 15 patients three males and 12, females. The mean age of patients was 28.5±4.9 years. The mean percent reduction was 18.3±10.6, in tretinoin/ammonium lactate group and 25.7±11.8 in laser group (P=0.004). Conclusion: These findings indicate that the application of alexandrite laser is a relative effective method for treatment of axillary-AN. However, this issue requires further studies with prolonged follow-up period

The relationship between motivating tasks and academic resiliency: The mediating role of mastery goals and perceived competence

Background and Objectives:In academic situations, having the opportunity to succeed and rebuild learning increases students' self-confidence in achieving success. Teaching such learners the path to progress and showing the results of hard work makes them strive to master the learning situation. The result is a sense of control and autonomy along with a sense of value. Such instance causes the learner to insist, commit, and work harder without fear of failure to achieve success. Therefore, the importance of the present study is to theoretically determine and discover the model or how to place individual and environmental factors affecting academic resilience. From a practical point of view, this study aims to clarify the importance of individual and environmental factors affecting resilience in education. The aim of this study was to explore the relationship between motivating tasks and academic resiliency and Also determination mediating role of mastery goals and perceived competence. Methods: The present study utilizes a correlational research method using causal relationship modeling methods. The research method applied to this study was structural equation modeling. The target population of the study comprised Tehran universities students who were studying at education and psychology faculties in the academic year of 2014-2015. The sample consisted of 414 students who were selected by random cluster sampling method. In other words, the sampling unit was the classes rather than the individuals. The instruments used in this study were: Classroom Goals Structures, Achievement Goal Orientation, Perceived Competence Scale and Academic Resiliency Questionnaire.   Findings: The results revealed that motivating tasks has direct effect to predict academic resiliency. Furthermore, mastery goals and perceived competence mediated the relationship of motivating tasks with academic resiliency. Discussion and implications of the results are presented in the study. Conclusion: Based on this, it can be concluded that the setting of attractive and motivating tasks leads to the adoption of goals of mastery, self -esteem and control over the learning position of learners. Based on research results, the assignment variable as an extrinsic variable directly affects the resilience variable (dependent variable) and also through intermediate variables (proficiency goals and competency perception). In addition, the significance of the error estimation of each of the constructs shows that other external factors can also affect the relationship of the variables of this study with academic resilience. Based on this, it is suggested that other factors such as internal or external motivation and functional goals by learners be investigated as variables affecting the structural model. In order to apply the results of this research, it is recommended that academic centers be designed in such a way that learners face attractive and challenging tasks and provide them with the opportunity to succeed and experience a sense of competence.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================