4,296 research outputs found
Guaiacol producing Alicyclobacillus spp. differentiation, detection, and control
Alicyclobacillus spp. are thermoacidophilic sporeformers that have significant impact on the pasteurized juice industry. Better detection and control methods are needed to minimize Alicyclobacillus related spoilage. The objective of this research is to improve existing detection and control methods by (1) the investigation of basic characteristics of guaiacol producing Alicyclobacillus and development of a novel detection method; and (2) the evaluation of Alicyclobacillus control method during storage and processing. Differences in growth characteristics were observed but not significant between guaiacol producing and non-guaiacol producing Alicyclobacillus. Enzyme and carbohydrate utilization profiles were variable depending on test isolates. Guaiacol formation was detectable within 12 h at 43 C and further accelerated under microaerophilic conditions. The newly developed SK2 agar provides selective identification of guaiacol producing Alicyclobacillus with a 95% correct identification rate. SK2 agar is the first known media providing selective isolation of guaiacol producing Alicyclobacillus. The effectiveness of aqueous and gas chlorine dioxide against Alicyclobacillus spores has been demonstrated. Greater than five log reductions were observed following 1 min and 1 h exposures to 120 ppm ClO2(aq) and 4.32 ppm ClO2(g), respectively
Was the Mandal Commission Right? Living Standard Differences between Backward Classes and Other Social Groups in India
Affirmative action has been at the heart of public policies towards the socially disadvantaged in India. Compensatory discrimination policies which have been adopted for the Scheduled Castes (SC) and Scheduled Tribes (ST) since independence were recommended for Other Backward Classes (OBC) by the Mandal Commission established by the Indian government in 1979. We examine why OBC have lower living standards, as measured by per capita household consumption expenditures, relative to the mainstream population, and whether these reasons are similar to those observed for SC and ST. We find that while the causes of the living standard gap for the OBC are broadly similar to those for the SC and ST, the role of educational attainment in explaining the gap is higher in importance for the OBC.living standards, caste, reservation policy, decomposition
Was the Mandal Commission Right? Living Standard Differences between Backward Classes and Other Social Groups in India
Affirmative action has been at the heart of public policies towards the socially disadvantaged in India. Compensatory discrimination policies which have been adopted for the Scheduled Castes (SC) and Scheduled Tribes (ST) since independence were recommended for Other Backward Classes (OBC) by the Mandal Commission established by the Indian government in 1979. We examine why OBC have lower living standards, as measured by per capita household consumption expenditures, relative to the mainstream population, and whether these reasons are similar to those observed for SC and ST. We find that while the causes of the living standard gap for the OBC are broadly similar to those for the SC and ST, the role of educational attainment in explaining the gap is higher in imporatnce for the OBC.
StoryDroid: Automated Generation of Storyboard for Android Apps
Mobile apps are now ubiquitous. Before developing a new app, the development
team usually endeavors painstaking efforts to review many existing apps with
similar purposes. The review process is crucial in the sense that it reduces
market risks and provides inspiration for app development. However, manual
exploration of hundreds of existing apps by different roles (e.g., product
manager, UI/UX designer, developer) in a development team can be ineffective.
For example, it is difficult to completely explore all the functionalities of
the app in a short period of time. Inspired by the conception of storyboard in
movie production, we propose a system, StoryDroid, to automatically generate
the storyboard for Android apps, and assist different roles to review apps
efficiently. Specifically, StoryDroid extracts the activity transition graph
and leverages static analysis techniques to render UI pages to visualize the
storyboard with the rendered pages. The mapping relations between UI pages and
the corresponding implementation code (e.g., layout code, activity code, and
method hierarchy) are also provided to users. Our comprehensive experiments
unveil that StoryDroid is effective and indeed useful to assist app
development. The outputs of StoryDroid enable several potential applications,
such as the recommendation of UI design and layout code
The conditional permutation test for independence while controlling for confounders
We propose a general new method, the conditional permutation test, for
testing the conditional independence of variables and given a
potentially high-dimensional random vector that may contain confounding
factors. The proposed test permutes entries of non-uniformly, so as to
respect the existing dependence between and and thus account for the
presence of these confounders. Like the conditional randomization test of
Cand\`es et al. (2018), our test relies on the availability of an approximation
to the distribution of . While Cand\`es et al. (2018)'s test uses
this estimate to draw new values, for our test we use this approximation to
design an appropriate non-uniform distribution on permutations of the
values already seen in the true data. We provide an efficient Markov Chain
Monte Carlo sampler for the implementation of our method, and establish bounds
on the Type I error in terms of the error in the approximation of the
conditional distribution of , finding that, for the worst case test
statistic, the inflation in Type I error of the conditional permutation test is
no larger than that of the conditional randomization test. We validate these
theoretical results with experiments on simulated data and on the Capital
Bikeshare data set.Comment: 31 pages, 4 figure
Kondo Signatures of a Quantum Magnetic Impurity in Topological Superconductors
We study the Kondo physics of a quantum magnetic impurity in two-dimensional topological superconductors (TSCs), either intrinsic or induced on the surface of a bulk topological insulator, using a numerical renormalization group technique. We show that, despite sharing the p+ip pairing symmetry, intrinsic and extrinsic TSCs host different physical processes that produce distinct Kondo signatures. Extrinsic TSCs harbor an unusual screening mechanism involving both electron and orbital degrees of freedom that produces rich and prominent Kondo phenomena, especially an intriguing pseudospin Kondo singlet state in the superconducting gap and a spatially anisotropic spin correlation. In sharp contrast, intrinsic TSCs support a robust impurity spin doublet ground state and an isotropic spin correlation. These findings advance fundamental knowledge of novel Kondo phenomena in TSCs and suggest experimental avenues for their detection and distinction
Identifying HER2 Inhibitors from Natural Products Database
The relationship between abnormal HER2 expression and cancer is important in cancer therapeutics. Formation and spread of cancer cells may be restricted by inhibiting HER2. We conducted ligand-based and structure-based studies to assess the potency of natural compounds as potential HER2 inhibitors. Multiple linear regression (MLR) and support vector machine (SVM) models were constructed to predict biological activities of natural compounds, and molecular dynamics (MD) was used to assess their stability with HER2 under a dynamic environment. Predicted bioactivities of the natural compounds ranged from 6.014–9.077 using MLR (r[superscript 2] = 0.7954) and 5.122–6.950 using SVM (r[superscript 2] = 0.8620). Both models were in agreement and suggest bioactivity based on candidate structure. Conformation changes caused by MD favored the formation of stabilizing H-bonds. All candidates had higher stability than Lapinatib, which may be due to the number and spatial distribution of additional H-bonds and hydrophobic interactions. Amino acids Lys724 and Lys736 are critical for binding in HER2, and Thr798, Cys805, and Asp808 are also important for increased stability. Candidates may block the entrance to the ATP binding site located within the inner regions and prevent downstream activation of HER2. Our multidirectional approach indicates that the natural compounds have good ligand efficacy in addition to stable binding affinities to HER2, and should be potent candidates of HER2 inhibitors. With regard to drug design, designing HER2 inhibitors with carboxyl or carbonyl groups available for H-bond formation with Lys724 and Lys736, and benzene groups for hydrophobic contact with Cys805 may improve protein-ligand stability.National Science Council of Taiwan (NSC 99-2221-E-039-013-)Committee on Chinese Medicine and Pharmacy (CCMP100-RD-030)China Medical University and Asia University (CMU98-TCM)China Medical University and Asia University (CMU99-TCM)China Medical University and Asia University (CMU99-S-02)China Medical University and Asia University (CMU99-ASIA-25)China Medical University and Asia University (CMU99-ASIA-26)China Medical University and Asia University (CMU99-ASIA-27)China Medical University and Asia University (CMU99-ASIA-28)Taiwan Department of Health. Clinical Trial and Research Center of Excellence (DOH100-TD-B-111-004)Taiwan Department of Health. Cancer Research Center of Excellence (DOH100-TD-C-111-005
A Robust RGBD Slam System for 3D Environment with Planar Surfaces
With the increasing popularity of RGB-depth (RGB-D) sensors such as the Microsoft Kinect, there have been much research on capturing and reconstructing 3D environments using a movable RGB-D sensor. The key process behind these kinds of simultaneous location and mapping (SLAM) systems is the iterative closest point or ICP algorithm, which is an iterative algorithm that can estimate the rigid movement of the camera based on the captured 3D point clouds. While ICP is a well-studied algorithm, it is problematic when it is used in scanning large planar regions such as wall surfaces in a room. The lack of depth variations on planar surfaces makes the global alignment an ill-conditioned problem. In this paper, we present a novel approach for registering 3D point clouds by combining both color and depth information. Instead of directly searching for point correspondences among 3D data, the proposed method first extracts features from the RGB images, and then back-projects the features to the 3D space to identify more reliable correspondences. These color correspondences form the initial input to the ICP procedure which then proceeds to refine the alignment. Experimental results show that our proposed approach can achieve better accuracy than existing SLAMs in reconstructing indoor environments with large planar surfaces
Protein diversification through post-translational modifications, alternative splicing, and gene duplication
Proteins provide the basis for cellular function. Having multiple versions of the same protein within a single organism provides a way of regulating its activity or developing novel functions. Post-translational modifications of proteins, by means of adding/removing chemical groups to amino acids, allow for a well-regulated and controlled way of generating functionally distinct protein species. Alternative splicing is another method with which organisms possibly generate new isoforms. Additionally, gene duplication events throughout evolution generate multiple paralogs of the same genes, resulting in multiple versions of the same protein within an organism. In this review, we discuss recent advancements in the study of these three methods of protein diversification and provide illustrative examples of how they affect protein structure and function
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