User-initialized active contour segmentation and golden-angle real-time cardiovascular magnetic resonance enable accurate assessment of LV function in patients with sinus rhythm and arrhythmias.

BackgroundData obtained during arrhythmia is retained in real-time cardiovascular magnetic resonance (rt-CMR), but there is limited and inconsistent evidence to show that rt-CMR can accurately assess beat-to-beat variation in left ventricular (LV) function or during an arrhythmia.MethodsMulti-slice, short axis cine and real-time golden-angle radial CMR data was collected in 22 clinical patients (18 in sinus rhythm and 4 patients with arrhythmia). A user-initialized active contour segmentation (ACS) software was validated via comparison to manual segmentation on clinically accepted software. For each image in the 2D acquisitions, slice volume was calculated and global LV volumes were estimated via summation across the LV using multiple slices. Real-time imaging data was reconstructed using different image exposure times and frame rates to evaluate the effect of temporal resolution on measured function in each slice via ACS. Finally, global volumetric function of ectopic and non-ectopic beats was measured using ACS in patients with arrhythmias.ResultsACS provides global LV volume measurements that are not significantly different from manual quantification of retrospectively gated cine images in sinus rhythm patients. With an exposure time of 95.2 ms and a frame rate of > 89 frames per second, golden-angle real-time imaging accurately captures hemodynamic function over a range of patient heart rates. In four patients with frequent ectopic contractions, initial quantification of the impact of ectopic beats on hemodynamic function was demonstrated.ConclusionUser-initialized active contours and golden-angle real-time radial CMR can be used to determine time-varying LV function in patients. These methods will be very useful for the assessment of LV function in patients with frequent arrhythmias

A Process Framework for Designing Software Reference Architectures for Providing Tools as a Service

Product-Focused Software Process ImprovementSoftware Reference Architecture (SRA), which is a generic architecture solution for a specific type of software systems, provides foundation for the design of concrete architectures in terms of architecture design guidelines and architecture elements. The complexity and size of certain types of software systems need customized and systematic SRA design and evaluation methods. In this paper, we present a software Reference Architecture Design process Framework (RADeF) that can be used for analysis, design and evaluation of the SRA for provisioning of Tools as a Service as part of a cloud-enabled workSPACE (TSPACE). The framework is based on the state of the art results from literature and our experiences with designing software architectures for cloud-based systems. We have applied RADeF SRA design two types of TSPACE: software architecting TSPACE and software implementation TSPACE. The presented framework emphasizes on keeping the conceptual meta-model of the domain under investigation at the core of SRA design strategy and use it as a guiding tool for design, evaluation, implementation and evolution of the SRA. The framework also emphasizes to consider the nature of the tools to be provisioned and underlying cloud platforms to be used while designing SRA. The framework recommends adoption of the multi-faceted approach for evaluation of SRA and quantifiable measurement scheme to evaluate quality of the SRA. We foresee that RADeF can facilitate software architects and researchers during design, application and evaluation of a SRA and its instantiations into concrete software systems.Muhammad Aufeef Chauhan, Muhammad Ali Babar, and Christian W. Probs

BETULA: Numerically Stable CF-Trees for BIRCH Clustering

BIRCH clustering is a widely known approach for clustering, that has influenced much subsequent research and commercial products. The key contribution of BIRCH is the Clustering Feature tree (CF-Tree), which is a compressed representation of the input data. As new data arrives, the tree is eventually rebuilt to increase the compression. Afterward, the leaves of the tree are used for clustering. Because of the data compression, this method is very scalable. The idea has been adopted for example for k-means, data stream, and density-based clustering. Clustering features used by BIRCH are simple summary statistics that can easily be updated with new data: the number of points, the linear sums, and the sum of squared values. Unfortunately, how the sum of squares is then used in BIRCH is prone to catastrophic cancellation. We introduce a replacement cluster feature that does not have this numeric problem, that is not much more expensive to maintain, and which makes many computations simpler and hence more efficient. These cluster features can also easily be used in other work derived from BIRCH, such as algorithms for streaming data. In the experiments, we demonstrate the numerical problem and compare the performance of the original algorithm compared to the improved cluster features

Effect of crystalline disorder on quantum tunneling in the single-molecule magnet Mn12 benzoate

10 páginas, 9 figuras, 1 tabla.-- PACS number(s): 75.45.+j, 75.50.Xx, 75.60.Jk, 75.50.Kj.-- et al.We report a detailed study of the effects that crystalline disorder has on the magnetic relaxation and quantum tunneling of Mn12 benzoate clusters. Thanks to the absence of interstitial molecules in the crystal structure of this molecular compound, we have been able to isolate the influence of long-range crystalline disorder. For this, we compare results obtained under two extreme situations: a crystalline sample and a nearly amorphous material. The results show that crystalline disorder affects little the anisotropy, magnetic relaxation, and quantum tunneling of these materials. It follows that disorder is not a necessary ingredient for the existence of magnetic quantum tunneling. The results unveil, however, a subtle influence of crystallinity via the modification of the symmetry of dipole-dipole interactions. The faster tunneling rates measured for the amorphous material are accounted for by a narrower distribution of dipolar bias in this material, as compared with the crystalline sample.This work has been partly funded by Grants No. MAT2009-13977-C03, No. MAT2008-06542- C04, and No. CSD2007-00010 from the Spanish Ministerio de Ciencia e Innovación, and NABISUP from DGA. We acknowledge funding from Acción Integrada under Grant No. HA2006-0051 and the Network of Excellence MAGMANet. J.v.S and S.D. acknowledge the financial support of the Deutsche Forschungsgemeinschaft (DFG) and the DAAD. Ch.C. and I.I. acknowledge the Spanish Ministerio de Ciencia e Innovación.Peer reviewe

Towards the development of sustainable tourism in Pakistan : a study of the role of tour operators

The literature on sustainable tourism is scant, particularly in the least developed countries. Very few studies touch upon the concept and no holistic theoretical or conceptual frameworks around the idea of sustainable tourism have been formulated. This study aims at exploring the role of tour operators in developing sustainable tourism in Pakistan and how the tour operators (TOs) conceive their role in this regard. TOs were reached through phone calls, emails, and virtual sources as face-to-face interviews were not possible due to COVID-19 pandemic and restrictions on travel by the government. In-depth interviews were conducted to gather data. Results suggest that the TOs although realize the importance of social, environmental, and economic dimensions of tourism on the communities but have no management systems in place to cater accordingly. There are no incentives in place by the government facilitate TOs to design and implement such systems. The TOs do not select a destination based on Global Sustainable Tourism Council criterion, but rather the selection of destination is mostly demand-based and profit-oriented. The study suggests that corporate profit motive is the sole criterion for decision making and is one of the major causes impeding sustainable tourism in Pakistan. The role of TOs in developing sustainable tourism is vague as the TOs do not have any systems in place to implement sustainable models. The study recommends that efforts need to be put in place to incentivize sustainable tourism in Pakistan and proper laws should be set forth by the authorities to comply by the TOs. The role of TOs is important and understood, however, there is a need to put proper systems in place

Semi-automatic conversion of BioProp semantic annotation to PASBio annotation

<p>Abstract</p> <p>Background</p> <p>Semantic role labeling (SRL) is an important text analysis technique. In SRL, sentences are represented by one or more predicate-argument structures (PAS). Each PAS is composed of a predicate (verb) and several arguments (noun phrases, adverbial phrases, etc.) with different semantic roles, including main arguments (agent or patient) as well as adjunct arguments (time, manner, or location). PropBank is the most widely used PAS corpus and annotation format in the newswire domain. In the biomedical field, however, more detailed and restrictive PAS annotation formats such as PASBio are popular. Unfortunately, due to the lack of an annotated PASBio corpus, no publicly available machine-learning (ML) based SRL systems based on PASBio have been developed. In previous work, we constructed a biomedical corpus based on the PropBank standard called BioProp, on which we developed an ML-based SRL system, BIOSMILE. In this paper, we aim to build a system to convert BIOSMILE's BioProp annotation output to PASBio annotation. Our system consists of BIOSMILE in combination with a BioProp-PASBio rule-based converter, and an additional semi-automatic rule generator.</p> <p>Results</p> <p>Our first experiment evaluated our rule-based converter's performance independently from BIOSMILE performance. The converter achieved an F-score of 85.29%. The second experiment evaluated combined system (BIOSMILE + rule-based converter). The system achieved an F-score of 69.08% for PASBio's 29 verbs.</p> <p>Conclusion</p> <p>Our approach allows PAS conversion between BioProp and PASBio annotation using BIOSMILE alongside our newly developed semi-automatic rule generator and rule-based converter. Our system can match the performance of other state-of-the-art domain-specific ML-based SRL systems and can be easily customized for PASBio application development.</p

Molecular signatures of maturing dendritic cells: implications for testing the quality of dendritic cell therapies

<p>Abstract</p> <p>Background</p> <p>Dendritic cells (DCs) are often produced by granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) stimulation of monocytes. To improve the effectiveness of DC adoptive immune cancer therapy, many different agents have been used to mature DCs. We analyzed the kinetics of DC maturation by lipopolysaccharide (LPS) and interferon-γ (IFN-γ) induction in order to characterize the usefulness of mature DCs (mDCs) for immune therapy and to identify biomarkers for assessing the quality of mDCs.</p> <p>Methods</p> <p>Peripheral blood mononuclear cells were collected from 6 healthy subjects by apheresis, monocytes were isolated by elutriation, and immature DCs (iDCs) were produced by 3 days of culture with GM-CSF and IL-4. The iDCs were sampled after 4, 8 and 24 hours in culture with LPS and IFN-γ and were then assessed by flow cytometry, ELISA, and global gene and microRNA (miRNA) expression analysis.</p> <p>Results</p> <p>After 24 hours of LPS and IFN-γ stimulation, DC surface expression of CD80, CD83, CD86, and HLA Class II antigens were up-regulated. Th1 attractant genes such as CXCL9, CXCL10, CXCL11 and CCL5 were up-regulated during maturation but not Treg attractants such as CCL22 and CXCL12. The expression of classical mDC biomarker genes CD83, CCR7, CCL5, CCL8, SOD2, MT2A, OASL, GBP1 and HES4 were up-regulated throughout maturation while MTIB, MTIE, MTIG, MTIH, GADD45A and LAMP3 were only up-regulated late in maturation. The expression of miR-155 was up-regulated 8-fold in mDCs.</p> <p>Conclusion</p> <p>DCs, matured with LPS and IFN-γ, were characterized by increased levels of Th1 attractants as opposed to Treg attractants and may be particularly effective for adoptive immune cancer therapy.</p

Ten-year follow-up of giant basilar aneurysm treated by sole stenting technique: a case report

<p>Abstract</p> <p>Introduction</p> <p>The sole stenting technique has emerged as a new tool for the management of intracranial aneurysms. However, several concerns have emerged about the long-term behavior of intracranial stents, particularly their safety and efficacy.</p> <p>Case presentation</p> <p>We present the first case of an intracranial aneurysm intentionally treated with the sole stenting technique. After ten years of clinical and imaging follow-up, the lesion has healed and no intrastent stenosis is observed.</p> <p>Several issues concerning this technique are discussed. For instance, the modification of the angle and intra-aneurysmal thrombosis may account as positive effects; negative outcomes include in-stent thrombosis or stenosis.</p> <p>Conclusions</p> <p>This case report, involving a long clinical and imaging follow-up, provides an example of the effectiveness, safety, durability and simplicity of the sole stenting technique in the management of intracranial aneurysms.</p

Pareto optimality solution of the multi-objective photogrammetric resection-intersection problem

Reconstruction of architectural structures from photographs has recently experienced intensive efforts in computer vision research. This is achieved through the solution of nonlinear least squares (NLS) problems to obtain accurate structure and motion estimates. In Photogrammetry, NLS contribute to the determination of the 3-dimensional (3D) terrain models from the images taken from photographs. The traditional NLS approach for solving the resection-intersection problem based on implicit formulation on the one hand suffers from the lack of provision by which the involved variables can be weighted. On the other hand, incorporation of explicit formulation expresses the objectives to be minimized in different forms, thus resulting in different parametric values for the estimated parameters at non-zero residuals. Sometimes, these objectives may conflict in a Pareto sense, namely, a small change in the parameters results in the increase of one objective and a decrease of the other, as is often the case in multi-objective problems. Such is often the case with error-in-all-variable (EIV) models, e.g., in the resection-intersection problem where such change in the parameters could be caused by errors in both image and reference coordinates.This study proposes the Pareto optimal approach as a possible improvement to the solution of the resection-intersection problem, where it provides simultaneous estimation of the coordinates and orientation parameters of the cameras in a two or multistation camera system on the basis of a properly weighted multi-objective function. This objective represents the weighted sum of the square of the direct explicit differences of the measured and computed ground as well as the image coordinates. The effectiveness of the proposed method is demonstrated by two camera calibration problems, where the internal and external orientation parameters are estimated on the basis of the collinearity equations, employing the data of a Manhattan-type test field as well as the data of an outdoor, real case experiment. In addition, an architectural structural reconstruction of the Merton college court in Oxford (UK) via estimation of camera matrices is also presented. Although these two problems are different, where the first case considers the error reduction of the image and spatial coordinates, while the second case considers the precision of the space coordinates, the Pareto optimality can handle both problems in a general and flexible way

Interferon-α resistance in renal carcinoma cells is associated with defective induction of signal transducer and activator of transcription 1 which can be restored by a supernatant of phorbol 12-myristate 13-acetate stimulated peripheral blood mononuclear cells

Therapy of selected human malignancies with interferon-α is widely accepted but often complicated by the emergence of interferon-α resistance. Interferon is a pleiotropic cytokine with antiproliferative, antitumour, antiviral and immunmodulatory effect; it signals through the Jak-STAT signal transduction pathway where signal transducer and activator of transcription 1 plays an important role. Here we report both, a lack of signal transducer and activator of transcription induction in interferon-α resistant renal cell carcinoma cells and signal transducer and activator of transcription 1 reinduction of phorbol 12-myristate 13-acetate-stimulated peripheral blood mononuclear cells supernatant. Preliminary experiments on the identification of the molecules that reinducing signal transducers and activators of transcription 1 indicate that interferon-γ may be the responsible candidate cytokine, but several others may be involved as well. This work provides the basis for therapeutic strategies directed at the molecular modulation of interferon-α resistance in human neoplasms