A Systemic Approach to Consider Complexity in Sawmill Modeling

The lumber industry is challenged to operate more efficiently. Sawmill systems use much equipment with various technologies and their management methods are very much influenced by size of operation, employee skills, hierarchy levels, and the high volatility of softwood lumber commodity markets. Because of interactions between the different manufacturing system components, its management becomes a complex matter. It is therefore difficult to assess the effect of given perturbations or improvements on the overall system.This study proposes a modeling approach based on the concept of system that provides a comprehensive view for modeling and analyzing sawmill systems. Adaptations of existing formalisms to represent operating, information, and decision sub-systems are put forward, while assembling these three sub-systems in an overall model gives a new vision of the sawmill and a powerful tool for systems integration. This modeling approach could be used for diagnostic as well as for sawmill improvement. Various examples are provided on the application of this approach

A novel antibacterial peptide derived from Crocodylus siamensis haemoglobin hydrolysate induces membrane permeabilization causing iron dysregulation, oxidative stress and bacterial death

Aims A novel antibacterial peptide from Crocodylus siamensis haemoglobin hydrolysate (CHH) was characterized for antimicrobial activity. Methods and Results CHHs were hydrolysed for 2 h (2 h-CHH), 4 h (4h-CHH), 6 h (6 h-CHH) and 8 h (8 h-CHH). The 8 h-CHH showed antibacterial activity against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa at concentrations of 20, 20, 20 and 10 mg ml−1 (w/v) respectively. Fluorescent microscopy revealed that the 8 h-CHH had bactericidal activity against E. coli and P. aeruginosa. β-galactosidase assay supported by RT-qPCR demonstrated that the 8 h-CHH resulted in differential expression of genes involved in iron homeostasis (ftnA and bfd) and oxidative stress (sodA, soxR and oxyR). Siderophore assay indicated that the 8 h-CHH also impaired siderophore production with diminished expression of pvdF. This pattern of gene expression suggests that the 8 h-CHH triggers the release of free ferric ions in the cytoplasm. However, decreased expression of genes associated with the SOS response (recA and lexA) in combination with neutral comet revealed that no DNA damage was caused by 8 h-CHH. Membrane permeabilization assay indicated that 8 h-CHH caused membrane leakage thought to mediate the antibacterial and iron-stress responses observed, due to loss of regulated iron transport. The novel active peptide from 8 h-CHH was determined as QAIIHNEKVQAHGKKVL (QL17), with 41% hydrophobicity and +2 net charge. Conclusions The QAIIHNEKVQAHGKKVL fragment of C. siamensis haemoglobin is antibacterial via a mechanism that likely relies on iron dysregulation and oxidative stress which results in bacterial death. Significance and Impact of the Study We have described for the first time, a novel peptide derived from C. siamensis haemoglobin hydrolysate that has the potential to be developed as a novel antimicrobial peptide

Determination of the volume-specific surface area by using transmission electron tomography for characterization and definition of nanomaterials

<p>Abstract</p> <p>Background</p> <p>Transmission electron microscopy (TEM) remains an important technique to investigate the size, shape and surface characteristics of particles at the nanometer scale. Resulting micrographs are two dimensional projections of objects and their interpretation can be difficult. Recently, electron tomography (ET) is increasingly used to reveal the morphology of nanomaterials (NM) in 3D. In this study, we examined the feasibility to visualize and measure silica and gold NM in suspension using conventional bright field electron tomography.</p> <p>Results</p> <p>The general morphology of gold and silica NM was visualized in 3D by conventional TEM in bright field mode. In orthoslices of the examined NM the surface features of a NM could be seen and measured without interference of higher or lower lying structures inherent to conventional TEM. Segmentation by isosurface rendering allowed visualizing the 3D information of an electron tomographic reconstruction in greater detail than digital slicing. From the 3D reconstructions, the surface area and the volume of the examined NM could be estimated directly and the volume-specific surface area (VSSA) was calculated. The mean VSSA of all examined NM was significantly larger than the threshold of 60 m²/cm³.</p> <p>The high correlation between the measured values of area and volume gold nanoparticles with a known spherical morphology and the areas and volumes calculated from the equivalent circle diameter (ECD) of projected nanoparticles (NP) indicates that the values measured from electron tomographic reconstructions are valid for these gold particles.</p> <p>Conclusion</p> <p>The characterization and definition of the examined gold and silica NM can benefit from application of conventional bright field electron tomography: the NM can be visualized in 3D, while surface features and the VSSA can be measured.</p

Dynamic trace-based sampling algorithm for memory usage tracking of enterprise applications

Excessive memory usage in software applications has become a frequent issue. A high degree of parallelism and the monitoring difficulty for the developer can quickly lead to memory shortage, or can increase the duration of garbage collection cycles. There are several solutions introduced to monitor memory usage in software. However they are neither efficient nor scalable. In this paper, we propose a dynamic tracing-based sampling algorithm to collect and analyse run time information and metrics for memory usage. It is implemented as a kernel module which gathers memory usage data from operating system structures only when a predefined condition is set or a threshold is passed. The thresholds and conditions are preset but can be changed dynamically, based on the application behavior. We tested our solutions to monitor several applications and our evaluation results show that the proposed method generates compact trace data and reduces the time needed for the analysis, without loosing precision

Co-channel interference and background noise in κ - μ fading channels

In this letter, we derive novel analytical and closed form expressions for the outage probability, when the signal-of- interest (SoI) and the interferer experience kappa-mu fading in the presence of Gaussian noise. Most importantly, these expressions hold true for independent and non-identically distributed kappa-mu variates, without parameter constraints. We also find the asymptotic behaviour when the average signal to noise ratio of the SoI is significantly larger than that of the interferer. It is worth highlighting that our new solutions are very general owing to the flexibility of the kappa-mu fading model21512151218CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ304248/2014-2This work was supported by the U.K. Engineering and Physical Sciences Research Council under Grant Reference EP/L026074/1 and by CNPq under Grant Reference 304248/2014-2

The complex α-μ fading channel with OFDM application

The aims of this paper are threefold: (i) to present a model for the complex - fading channel; (ii) to propose an efficient, simple, and general method to generate complex - samples; (iii) to make use of this channel in order to assess the bit error rate performance of an OFDM system. An analytical framework is then used, whose output is validated through Monte Carlo simulation. Several important conclusions concerning the system performance as a function of the channel parameters, namely, nonlinearity, clustering, and power imbalance of in-phase and quadrature components, are drawn2017Recent advances in RF propagation modeling for 5G systemsFINANCIADORA DE ESTUDOS E PROJETOS - FINEP01.14.0231.0

Fading Evaluation in the mm-Wave Band

[EN] A thorough millimeter-wave measurement campaign is carried out in an indoor environment with an aim at characterizing the short-term fading channel behavior. The measurements are conducted in a variety of scenarios, with frequencies ranging from 55 GHz to 65 GHz, in line-of-sight and non-line-of-sight conditions, and combinations of horizontal and vertical polarizations at both transmitter and receiver. A number of fading models are tested, namely Rayleigh, Rice, Nakagami-m, alpha-mu, kappa-mu, eta-mu, and alpha-eta-kappa-mu. The statistics under analysis are those characterizing the fading amplitude and the frequency selectivity. In particular, the probability density and cumulative distribution functions for the former and level crossing rate per bandwidth unit for the latter are the respective first-and second-order statistics used. To this end, from the experimental data, the parameters of the models are estimated and the corresponding theoretical curves are plotted and compared with the empirical ones. Whereas the required theoretical formulations of the first-order statistics of these models are already well known, those of the second-order statistics as well as these fitting process in such a band shown here are unprecedented in the literature.This work was supported in part by CNPq under Grant 304248/2014-2 and Grant 308365/2017-8 and in part by RNP, with resources from MCTIC, Grant No. No 01250.075413/2018-04, under the Radiocommunication Reference Center (Centro de Referencia em Radiocomunicacoes -CRR) project of the National Institute of Telecommunications (Instituto Nacional de Telecomunicacoes -Inatel), Brazil, and by the Ministerio de Economia, Industria y Competitividad of the Spanish Government under the national project TEC2017-86779-C2-2-R, through the Agencia Estatal de Investigacion (AEI) and the Fondo Europeo de Desarrollo Regional (FEDER). The associate editor coordinating the review of this article and approving it for publication was T. Kim.Rufino Marins, TR.; Dos Anjos, AA.; Rodrigo Peñarrocha, VM.; Rubio Arjona, L.; Reig, J.; Amaral De Souza, RA.; Yacoub, MD. (2019). Fading Evaluation in the mm-Wave Band. IEEE Transactions on Communications. 67(12):8725-8738. https://doi.org/10.1109/TCOMM.2019.2941493S87258738671

Non-Invasive Detection of Coronary Artery Disease in Patients With Left Bundle Branch Block Using 64-Slice Computed Tomography

ObjectivesThe goal of this study was to evaluate the diagnostic accuracy of 64-slice computed tomography (CT) to identify coronary artery disease (CAD) in patients with complete left bundle branch block (LBBB).BackgroundLeft bundle branch block increases risk of cardiac mortality, and prognosis is primarily determined by the underlying coronary disease. Non-invasive stress tests have limited performance, and conventional coronary angiography (CCA) is usually required.MethodsSixty-six consecutive patients with complete LBBB and sinus rhythm admitted for CCA were enrolled. Computed tomography was performed 3 ± 3.9 days before CCA. The accuracy of 64-slice CT to detect significant stenosis (>50% lumen narrowing) was compared with quantitative coronary angiography. All segments were analyzed regardless of image quality from coronary calcification or motion artifacts. Results were analyzed by patient and by coronary segment (990) using the American Heart Association 15-segment model.ResultsLower heart rates were associated with improved image quality. Computed tomography correctly identified 35 of 37 (95%) patients without significant stenosis and 28 of 29 (97%) patients with significant stenosis on CCA. Computed tomography correctly assessed 68 of 94 (72%) significant stenosis. Overall, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice CT for identifying CAD by patient was 95%, 97%, 95%, 93%, and 97%, respectively, and by segment was 97%, 72%, 99%, 91%, and 97%, respectively.ConclusionsIn a routine clinical practice, 64-slice CT detects with excellent accuracy a significant CAD in patients with complete LBBB. A normal CT in this clinical setting is a robust tool to act as a filter and avoid invasive diagnostic procedures