The Role of Temperature and Lipid Charge on Intake/Uptake of Cationic Gold Nanoparticles into Lipid Bilayers

Understanding the molecular mechanisms governing nanoparticle–membrane interactions is of prime importance for drug delivery and biomedical applications. Neutron reflectometry (NR) experiments are combined with atomistic and coarse‐grained molecular dynamics (MD) simulations to study the interaction between cationic gold nanoparticles (AuNPs) and model lipid membranes composed of a mixture of zwitterionic di‐stearoyl‐phosphatidylcholine (DSPC) and anionic di‐stearoyl‐phosphatidylglycerol (DSPG). MD simulations show that the interaction between AuNPs and a pure DSPC lipid bilayer is modulated by a free energy barrier. This can be overcome by increasing temperature, which promotes an irreversible AuNP incorporation into the lipid bilayer. NR experiments confirm the encapsulation of the AuNPs within the lipid bilayer at temperatures around 55 °C. In contrast, the AuNP adsorption is weak and impaired by heating for a DSPC–DSPG (3:1) lipid bilayer. These results demonstrate that both the lipid charge and the temperature play pivotal roles in AuNP–membrane interactions. Furthermore, NR experiments indicate that the (negative) DSPG lipids are associated with lipid extraction upon AuNP adsorption, which is confirmed by coarse‐grained MD simulations as a lipid‐crawling effect driving further AuNP aggregation. Overall, the obtained detailed molecular view of the interaction mechanisms sheds light on AuNP incorporation and membrane destabilization.     

Selection of control structure for distributed model predictive control in the presence of model errors

This paper presents a new methodology for selecting control structure in the context of distributed model predictive control. An index was developed to quantify the performance of distributed MPC strategies in the presence of model errors. This index was used for two purposes: to solve the decomposition problem whereby the process is decomposed into parts and to compare distributed MPC strategies with different degrees of coordination. Then, a multi-objective Mixed Integer Nonlinear Programming MINLP formulation is proposed to achieve an optimal trade-off between performance and structure simplicity.Four examples are considered to illustrate the methodology. The simulation results are consistent with the conclusions obtained from the analysis. The proposed methodology can be applied at the design stage to select the best control configuration in the presence of model errors.     

A low complexity time-scaling expansion algorithm of speech signals suitable for real time implementation

This paper presents the development and implementation of a variable rate time-scaling expansion system for speech signals, based on the pitch information, in which only the voiced segments are expanded, keeping the unvoiced and silence segments unchanged. The proposed system was first evaluated by computer simulation and then implemented on a digital signal processor (DSP). Time-domain, frequency-domain, mean opinion score (MOS) and diagnostic rhyme test (DRT) evaluations were done to test the actual performance of developed algorithm, which show that the proposed system allows improving the learning level of foreign language students as well as the understanding ability of elderly people. Objective tests also were carried out in order to probe similarity between the original and the expanded signals. Applying an iterative refinement of the C source code it was possible to obtain a real-time implementation. The current implemented algorithm requires 11 kwords program memory and about 9 million of floating point operations per second (MFLOPS).     

Stages of Change Among Chinese People With Mental Illness: A Preliminary Study.

Objective: To determine the effect of self-efficacy and outcome expectancy on the readiness for rehabilitation among Chinese people with mental illness. Participants: Fifty-eight men and 62 women with chronic mental illness. Outcome Measures: Change Assessment Questionnaire for People With Severe and Persistent Mental Illness, Task-Specific Self-Efficacy Scale for People With Mental Illness, and Outcome-Expectancy Scale for People With Mental Illness. Results: Chinese people with mental illness can be meaningfully classified into 4 stages of change (SOC) groups: precontemplation, contemplation, ambivalent-conforming, and action-maintenance. SOCs are related to self-efficacy in interpersonal, symptoms management, and help-seeking skills as well as expectations about the benefit of social and coping skills. Conclusion: The SOC concept is useful for tailoring culturally sensitive psychiatric rehabilitation interventions for Chinese people with mental illness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A computational procedure for response statistics-based optimization of stochastic non-linear FE-models

An approach for an efficient solution of response statistics-based optimization problems of non-linear FE systems under stochastic loading is presented. A sequential approximate optimization approach, where approximate stochastic analyses are used during portions of the optimization process, is implemented in the proposed formulation. In this approach, analytical approximations of the performance functions in terms of the design variables are considered during the optimization process. The analytical approximations are constructed by combining a mixed linearization approach with a stochastic response sensitivity analysis. The state of the system is defined in terms of the statistical second-moment characteristics of the structural response. The stochastic loading and the response of the system are represented by an orthogonal series expansion of the corresponding covariance matrices. In particular, a truncated Karhunen-Loève (K-L) expansion is applied. The system of non-linear equations is replaced by a statistical equivalent linear system. The evaluation of the K-L vectors is carried out by an efficient procedure that combines local linearization, modal analysis and static response of higher structural modes. An illustrative example is presented that shows the efficiency of the proposed methodology: it considers a building finite element model enforced with non-linear hysteretic devices and subject to a stochastic ground acceleration. Two types of problems are considered: a minimum structural weight design problem and an optimal non-linear device design problem.     

Scanning and tracking with independent cameras—a biologically motivated approach based on model predictive control

This paper presents a framework for visual scanning and target tracking with a set of independent pan-tilt cameras. The approach is systematic and based on Model Predictive Control (MPC), and was inspired by our understanding of the chameleon visual system. We make use of the most advanced results in the MPC theory in order to design the scanning and tracking controllers. The scanning algorithm combines information about the environment and a model for the motion of the target to perform optimal scanning based on stochastic MPC. The target tracking controller is a switched control combining smooth pursuit and saccades. Min-Max and minimum-time MPC theory is used for the design of the tracking control laws. We make use of the observed chameleon’s behavior to guide the scanning and the tracking controller design procedures, the way they are combined together and their tuning. Finally, simulative and experimental validation of the approach on a robotic chameleon head composed of two independent Pan-Tilt cameras is presented.

Opportunistic Activity Recognition in IoT Sensor Ecosystems via Multimodal Transfer Learning

Neural Processing Letters - Recognizing human activities seamlessly and ubiquitously is now closer than ever given the myriad of sensors readily deployed on and around users. However, the training...     

Segmentation and adaptive assimilation for detail-preserving display of high-dynamic range images

Realistic display of high-dynamic range images is a difficult problem. Previous methods for high-dynamic range image display suffer from halo artifacts or are computationally expensive. We present a novel method for computing local adaptation luminance that can be used with several different visual adaptation-based tone-reproduction operators for displaying visually accurate high-dynamic range images. The method uses fast image segmentation, grouping, and graph operations to generate local adaptation luminance. Results on several images show excellent dynamic range compression, while preserving detail without the presence of halo artifacts. With adaptive assimilation, the method can be configured to bring out a high-dynamic range appearance in the display image. The method is efficient in terms of processor and memory use.     

A Dynamic Network of Proteins Facilitate Cell Envelope Biogenesis in Gram-Negative Bacteria

Bacteria must maintain the ability to modify and repair the peptidoglycan layer without jeopardising its essential functions in cell shape, cellular integrity and intermolecular interactions. A range of new experimental techniques is bringing an advanced understanding of how bacteria regulate and achieve peptidoglycan synthesis, particularly in respect of the central role played by complexes of Sporulation, Elongation or Division (SEDs) and class B penicillin-binding proteins required for cell division, growth and shape. In this review we highlight relationships implicated by a bioinformatic approach between the outer membrane, cytoskeletal components, periplasmic control proteins, and cell elongation/division proteins to provide further perspective on the interactions of these cell division, growth and shape complexes. We detail the network of protein interactions that assist in the formation of peptidoglycan and highlight the increasingly dynamic and connected set of protein machinery and macrostructures that assist in creating the cell envelope layers in Gram-negative bacteria.     

Epidemiological comparisons of problems and positive qualities reported by adolescents in 24 countries.

In this study, the authors compared ratings of behavioral and emotional problems and positive qualities on the Youth Self-Report (T. M. Achenbach & L. A. Rescorla, 2001) by adolescents in general population samples from 24 countries (N = 27,206). For problem scales, country effect sizes (ESs) ranged from 3% to 9%, whereas those for gender and age ranged from less than 1% to 2%. Scores were significantly higher for girls than for boys on Internalizing Problems and significantly higher for boys than for girls on Externalizing Problems. Bicountry correlations for mean problem item scores averaged .69. For Total Problems, 17 of 24 countries scored within one standard deviation of the overall mean of 35.3. In the 19 countries for which parent ratings were also available, the mean of 20.5 for parent ratings was far lower than the self-report mean of 34.0 in the same 19 countries (d = 2.5). Results indicate considerable consistency across 24 countries in adolescents' self-reported problems but less consistency for positive qualities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)