In silico description of fluorescent probes in vivo

Fluorescent imaging in vivo has became one of the most powerful tools to follow the temporal and spatial localization of a variety of intracellular molecular events. Genetically encoded fluorescent indicators using the FRET effect are routinely used although the molecular basis regulating their functioning is not completely known. Here, the structural and dynamics properties of a commonly used FRET sensor for the second messenger cAMP based on the cAMP-binding domains of the regulatory subunit of Protein Kinase A are presented. Molecular dynamics simulations allowed pinpointing the main features of cAMP driven conformational transition and dissecting the contributions of geometric factors governing the functioning of the biosensor. Simulations suggest that, although orientational factors are not fully isotropic, they are highly dynamic making the inter-chromophore distance the dominant feature, determining the functioning of the probes. It is expected that this computer-aided methodology may state general basis for rational design strategies of fluorescent markers for in vivo imaging.     

Low-cost silicon neural probe: fabrication,electrochemical characterization and in vivo validation

Microsystem Technologies - This paper presents the fabrication of a silicon neural probe using low-cost microfabrication technologies, such as thin-films deposition, blade dicing, and...     

Medical image processing: An overview of and case study in the diagnosis of cardiac diseases

In this paper an overview is presented on R&D of medical imaging and image processing techniques in Japan during the last decade, focusing on case studies in the diagnosis of cardiac diseases.Various problems of image processing of left ventricular images obtained from x-ray, ultrasound and radionuclides are discussed. Also reviewed are boundary detection methods of left ventricular inner cavity and myocardium, analysis of left ventricular wall motion and various kinds of cardiac functions using conventional and newly developed methods, and display methods of these cardiac functions.Microcomputerized on-line image processing systems and a compound sector scan echocardiography using two probes developed for echocardiographic examinations are shown with some results in clinical applications.3-dimensional reconstruction methods of the left ventricle and other organs from multiple 2-dimensional images are shown with 3-dimensional shapes reconstructed from images by x-ray, ultrasound and radionuclides. Moreover, 3-dimensional functional images of the left ventricle are shown as well. Transferring the 3-dimensional consecutive left ventricular images during a cardiac cycle onto a CRT display under the control of a microprocessor, we can observe the pulsating 3-dimensional left ventricle on the CRT.     

Growth of the flat bones of the membranous neurocranium: A computational model

This article assumes two stages in the formation of the bones in the calvaria, the first one takes into account the formation of the primary centers of ossification. This step counts on the differentiation from mesenchymal cells into osteoblasts. A molecular mechanism is used based on a system of reaction-diffusion between two antagonistic molecules, which are BMP2 and Noggin. To this effect we used equations whose behavior allows finding Turing patterns that determine the location of the primary centers. In the second step of the model we used a molecule that is expressed by osteoblasts, called Dxl5 and that is expressed from the osteoblasts of each flat bone. This molecule allows bone growth through its borders through cell differentiation adjacent to each bone of the skull. The model has been implemented numerically using the finite element method. The results allow us to observe a good approximation of the formation of flat bones of the membranous skull as well as the formation of fontanelles and sutures.     

Proteomics in farm animals models of human diseases

The need to provide in vivo complex environments to understand human diseases strongly relies on the use of animal models, which traditionally include small rodents and rabbits. It is becoming increasingly evident that the few species utilised to date cannot be regarded as universal. There is a great need for new animal species that are naturally endowed with specific features relevant to human diseases. Farm animals, including pigs, cows, sheep and horses, represent a valid alternative to commonly utilised rodent models. There is an ample scope for the application of proteomic techniques in farm animals, and the establishment of several proteomic maps of plasma and tissue has clearly demonstrated that farm animals provide a disease environment that closely resembles that of human diseases. The present review offers a snapshot of how proteomic techniques have been applied to farm animals to improve their use as biomedical models. Focus will be on specific topics of biomedical research in which farm animal models have been characterised through the application of proteomic techniques.     

Analysis and characterization of complex reactor behaviour: A case study

This paper analyzes the steady state and dynamic behaviour of a reactor for production of silicon metal, a submerged arc furnace. The furnace behaviour has been analyzed through simulation studies using a detailed, industrially proven, mechanistic simulation model. The analysis reveals that the silicon furnace has changing and complex dynamic behaviour, including inverse responses and slow modes, especially close to optimality. The paper analyzes the causes of the changing dynamic behaviour. It also shows how the margins to optimality can be deduced from the dynamic response to changes in the carbon coverage input.     

In vivo laboratory validation of the physiometer: a measurement system for long-term recording of posture and movements in the workplace

Posture and movement are thought to be important risk factors for the development of work-related musculoskeletal disorders. Whole day occupational exposure assessment has typically used self-report or observation techniques, but the need for more accurate measurement is now recognised. The aim of this study was to compare the kinematic recordings of a frequently used field system (physiometer) with two laboratory-based systems (Fastrak and Peak) in vivo. Head, thorax and right arm kinematics were recorded simultaneously by the three systems whilst a subject performed 27 single and multiple plane physiological and simulated daily living task movement trials. Errors observed in the Fastrak and Peak data included gimbal lock and quadrant errors. Physiometer data errors included undervalues, overvalues and temporal errors of slow response and resonance. All three systems showed some cross-talk. Agreement between the physiometer and the other systems was generally high for physiological movements (R² > 0.8) and less for functional movements (R² > 0.5).

Statement of Relevance: The physiometer recording device can provide an indication of posture across time in the workplace; however, its accuracy is limited, particularly during functional movements. Further technology should be developed to unobtrusively capture accurate all day 3-D kinematics.     

Fluorescence sensing systems: In vivo detection of biophysical variations in field corn due to nitrogen supply

Leaf and canopy fluorescence properties of field corn (Zea mays L.) grown under varying levels of nitrogen (N) fertilization were characterized to provide an improved N sensing capability which may assist growers in site-specific N management decisions. In vivo fluorescence emissions can occur in the wavelength region from 300 to 800 nm and are dependent on the wavelength of illumination. These light emissions have been grouped into five primary bands with maxima most frequently received from corn at 320 nm (UV), 450 nm (blue), 530 nm (green), 685 nm (red), and 740 nm (far-red). Two active fluorescence sensing systems have been custom developed; a leaf level Fluorescence Imaging System (FIS), and a canopy level Laser Induced Fluorescence Imaging System (LIFIS). FIS sequentially acquires high-resolution images of fluorescence emission bands under darkened laboratory conditions, while LIFIS simultaneously acquires four band images of plant canopies ≥1 m² under ambient sunlit conditions. Fluorescence emissions induced by these systems along with additional biophysical measures of crop condition; namely, chlorophyll content, N/C ratio, leaf area index (LAI), and grain yield, exhibited similar curvilinear responses to levels of supplied N. A number of significant linear correlations were found among band emissions and several band ratios versus measures of crop condition. Significant differences were obtained for several fluorescence band ratios with respect to the level of supplied N. Leaf adaxial versus abaxial surface emissions exhibited opposing trends with respect to the level of supplied N. Evidence supports that this confounding effect could be removed in part by the green/blue and green/red ratio images. The FIS and LIFIS active fluorescence sensor systems yielded results which support the underlying hypothesis that leaf and canopy fluorescence emissions are associated with other biophysical attributes of crop growth and this information could potentially assist in the site-specific management of variable-rate N fertilization programs.     

The case for speech synthesis: An experiment in human engineering

Despite expected widespread use of computer speech synthesis in manufacturing and production applications, no one has yet determined the effects of synthesized speech on task performance. This laboratory study introduced speech synthesis in replicating parts of two previous experiments that had used human-voice feedback. Both instructions and productivity feedback were examined for their effect on arithmetic manipulation tasks. Findings show that there are interaction effects; it appears necessary to develop profiles of persons and conditions which predict how computer speech synthesis may be used most productively. We must attempt to determine the way that speech synthesizers may replace and enhance the communication process, while maintaining high motivation of people who interact with these machines.     

Aircraft detection: a case study in using human similarity measure

After the most prominent signal in an infrared image of the sky is extracted, the question is whether the signal corresponds to an aircraft. We present a new approach that avoids metric similarity measures and the use of thresholds, and instead attempts to learn similarity measures like those used by humans. In the absence of sufficient real data, the approach allows one to specifically generate an arbitrarily large number of training exemplars projecting near the classification boundary. Once trained on such a training set, the performance of our neural network-based system is comparable to that of a human expert and far better than a network trained only on the available real data. Furthermore, the results obtained are considerably better than those obtained using an Euclidean discriminator     

藏文文本中格助词的识别研究简

藏文信息处理中要对自然语言进行理解并生成且藏文格与语义有关,藏文格到目前为止都是研究者手动处理,而不是电脑处理,所以需开发出电脑替人自动识别格的软件是当前最急需研究的项目之一,从而藏文研究者和学习者可用此软件对藏文格进行自动识别,还能正确消除藏文语境歧义,而且在时间上、人力上都大大节省且提高了效率。本文通过研究藏文格的用法,建设藏文八格的知识库和藏文八格的算法及识别研究。     

Intelligent information processing in human resource management: an implementation case in China

Abstract: Information systems have been applied to human resource management (HRM) for decades. However, the way of using information systems and the way of processing information for HRM have evolved and dramatically improved over the last decade. More and more HRM systems today are being changed to e-HRM systems. This is mainly due to the advent of Internet technology and the emerging concept of business intelligence. Our study shows the evolution of information systems and information processing in the HRM domain and provides an implementation case in a large Chinese state-run factory. The experiences and lessons learned from this case reveal several common problems in developing information systems in the HRM domain.     

Levels of abstraction in designs of human–computer interaction: The case of e-mail

People process information at different levels of abstraction (e.g., talking about a topic in general terms and then going into the details). They move from one level to another but focus on a particular level at any specific moment. We see this behavior in the most common of tasks, such as solving problems, communicating and designing. This paper explores the implications of levels of abstraction on designing interactive systems. It demonstrates the idea by showing the feasibility and desirability of building a simple e-mail system based on the idea of levels of abstraction and testing its usability.We believe the implications of levels of abstraction on design are profound as regards the design of interactive systems that support dynamic behavior. Having shown the feasibility of some basic design implications, we call for empirical studies to test their usability and explore more advanced design implications.     

A rapid computational filter for predicting the rate of human renal clearance

In silico models that predict the rate of human renal clearance for a diverse set of drugs, that exhibit both active secretion and net re-absorption, have been produced using three statistical approaches. Partial Least Squares (PLS) and Random Forests (RF) have been used to produce continuous models whereas Classification And Regression Trees (CART) has only been used for a classification model. The best models generated from either PLS or RF produce significant models that can predict acids/zwitterions, bases and neutrals with approximate average fold errors of 3, 3 and 4, respectively, for an independent test set that covers oral drug-like property space. These models contain additional information on top of any influence arising from plasma protein binding on the rate of renal clearance. Classification And Regression Trees (CART) has been used to generate a classification tree leading to a simple set of Renal Clearance Rules (RCR) that can be applied to man. The rules are influenced by lipophilicity and ion class and can correctly predict 60% of an independent test set. These percentages increase to 71% and 79% for drugs with renal clearances of < 0.1 ml/min/kg and > 1 ml/min/kg, respectively. As far as the authors are aware these are the first set of models to appear in the literature that predict the rate of human renal clearance and can be used to manipulate molecular properties leading to new drugs that are less likely to fail due to renal clearance.     

Parametric characterization of the form of the human pupil from blurred noisy images

The fluctuation of the human pupil is an important parameter in order to make non-invasive diagnosis of many different diseases and in several clinical applications. The relevant measurement device, the pupillometer, consists in a CCD camera, which shoots the pupil. We suppose that the measured image is blurred by a Gaussian kernel and corrupted by an additive white noise; moreover an elliptic shape for the pupil is assumed. We here present the extension of a multiscale approach for edge detection to identify some parameters of the pupil: the location of its centre, the length of the semi-axes and the orientation of the corresponding ellipse. The chosen method requires knowledge about the degradation parameters of the assumed model; so we first present a simple but efficient method to determine such quantities for the measured image. Then we apply the edge detection procedure to identify points close to the pupil edge, within a chosen probability. Finally we find the optimal ellipse fitting a suitable subset of the previously detected edge points. Results are presented, with comparisons to other approaches for edge finding.     

Modelling of human alarm handling response times: a case study of the Ladbroke Grove rail accident in the UK

The purpose of the paper was to address the timeliness of the signaller's intervention in the Ladbroke Grove rail incident in the UK, as well as to consider the utility of human performance time modelling more generally. Human performance response time modelling is a critical area for Human Factors and Ergonomics research. This research applied two approaches to the same problem to see if they arrived at the same conclusion. The first modelling approach used the alarm initiated activity (AIA) model. This approach is useful for indicating general response times in emergency events, but it cannot comment in detail on any specific case. The second modelling approach employed a multi-modal critical path analysis (CPA) technique. The advantage of the latter approach is that it can be used to model a specific incident on the basis of the known factors from the accident inquiry. The results show that the AIA model produced an estimated response time of 17 s, whereas the CPA model produced an estimated response time of 19 s. This compares with the actual response time of the signaller of 18 s. The response time data from both approaches are concordant and suggest that the signaller's response time in the Ladbroke Grove rail accident was reasonable. This research has application to the modelling of human responses to emergency events in all domains. Rather than the forensic reconstruction approach used in this paper, the models could be used in a predictive manner to anticipate how long human operators of safety-critical systems might take to respond in emergency scenarios.     

Modelling of human alarm handling response times: a case study of the Ladbroke Grove rail accident in the UK

The purpose of the paper was to address the timeliness of the signaller's intervention in the Ladbroke Grove rail incident in the UK, as well as to consider the utility of human performance time modelling more generally. Human performance response time modelling is a critical area for Human Factors and Ergonomics research. This research applied two approaches to the same problem to see if they arrived at the same conclusion. The first modelling approach used the alarm initiated activity (AIA) model. This approach is useful for indicating general response times in emergency events, but it cannot comment in detail on any specific case. The second modelling approach employed a multi-modal critical path analysis (CPA) technique. The advantage of the latter approach is that it can be used to model a specific incident on the basis of the known factors from the accident inquiry. The results show that the AIA model produced an estimated response time of 17 s, whereas the CPA model produced an estimated response time of 19 s. This compares with the actual response time of the signaller of 18 s. The response time data from both approaches are concordant and suggest that the signaller's response time in the Ladbroke Grove rail accident was reasonable. This research has application to the modelling of human responses to emergency events in all domains. Rather than the forensic reconstruction approach used in this paper, the models could be used in a predictive manner to anticipate how long human operators of safety-critical systems might take to respond in emergency scenarios.