Miracle-dz/UniFAR-FTUs huggingface dataset:
New Models for Wolf-Rayet and O Star Populations in Young Starbursts

Using the latest stellar evolution models, theoretical stellar spectra, and a compilation of observed emission line strengths from Wolf-Rayet (W-R) stars, we construct evolutionary synthesis models for young starbursts. We explicitly distinguish between the various W-R subtypes (WN, WC, WO), whose relative frequency is a strong function of metallicity, and we treat O and Of stars separately. We calculate the numbers of O and W-R stars produced during a starburst and provide detailed predictions of UV and optical emission line strengths for both the W-R stellar lines and the major nebular hydrogen and helium emission lines, as a function of several input parameters related to the starburst episode. We also derive the theoretical frequency of W-R-rich starbursts. Our models predict that nebular He II λ4686 emission from a low-metallicity starburst should be associated with the presence of WC/WO stars and/or hot WN stars evolving to become WC/WO stars. In addition, W-R stars contribute to broad components beneath the nebular Balmer lines; the broad W-R component may constitute several percent of the total flux in the line. We review the various techniques used to derive the W-R and O star content from integrated spectra, assess their accuracy, and propose two new formulae to estimate the W-R/O number ratio from UV or optical spectra. We also explore the implications of the formation of W-R stars through mass transfer in close binary systems in instantaneous bursts. While the formation of W-R stars through Roche lobe overflow prolongs the W-R-dominated phase, there are clear observational signatures that allow us to distinguish the phases in which W-R stars are formed predominantly through single or binary star channels. In particular at low metallicities, when massive close binaries contribute significantly to the formation of W-R stars, the binary-dominated phase is expected to occur at ages corresponding to relatively low Hβ equivalent widths. The observational features predicted by our models allow a detailed quantitative determination of the massive star population in a starburst region (particularly in so-called "W-R galaxies") from its integrated spectrum and provide a means of deriving the burst properties (e.g., duration and age) and the parameters of the initial mass function of young starbursts. The model predictions should provide the most reliable determinations to date. They can also be used to test current theories of massive star evolution and atmospheres and to investigate the variation in stellar properties with metallicity.
Reducing the forwarding state requirements of point-to-multipoint trees using MPLS multicast

Multicasting enables efficient usage of network resources in applications that require group communication. In addition to the well known multicast applications, new communication technologies that can benefit from multicast keep emerging. A recent example are the various types of virtual private network (VPN) applications that carry customer traffic over public networks creating the illusion of a private network for each customer. Still, due to the difficulty of aggregating multicast destination addresses, multicasting suffers from the forwarding state scalability problems. In this work we investigate how the problem of multicast state scalability re-emerges in the VPN setting and how it can be effectively addressed there using the MPLS label based forwarding paradigm.
Splicing of internal large exons is defined by novel cis-acting sequence elements

Human internal exons have an average size of 147 nt, and most are <300 nt. This small size is thought to facilitate exon definition. A small number of large internal exons have been identified and shown to be alternatively spliced. We identified 1115 internal exons >1000 nt in the human genome; these were found in 5% of all protein-coding genes, and most were expressed and translated. Surprisingly, 40% of these were expressed at levels similar to the flanking exons, suggesting they were constitutively spliced. While all of the large exons had strong splice sites, the constitutively spliced large exons had a higher ratio of splicing enhancers/silencers and were more conserved across mammals than the alternatively spliced large exons. We asked if large exons contain specific sequences that promote splicing and identified 38 sequences enriched in the large exons relative to small exons. The consensus sequence is C-rich with a central invariant CA dinucleotide. Mutation of these sequences in a candidate large exon indicated that these are important for recognition of large exons by the splicing machinery. We propose that these sequences are large exon splicing enhancers (LESEs).
INTERACTION IN ASYNCHRONOUS WEB- BASED LEARNING ENVIRONMENTS: STRATEGIES SUPPORTED BY EDUCATIONAL RESEARCH

Because of the perceived advantages and the promotion of Web-based learning environments (WBLEs) by commercial interests as well as educational technologists, knowing how to develop and implement WBLEs will probably not be a choice, but a necessity for most educators and trainers in the future. However, many instructors still don’t understand the most effective strategies for designing and implementing effective WBLEs even though numerous studies have demonstrated that the success or failure of online learning depends largely on the quality of interaction within those learning environments. Indeed, it has been said learning is impossible without meaningful cognitive interaction. However, this kind of interaction does not occur by itself. The primary goal of this paper is to explore the importance and characteristics of meaningful interaction in online learning, especially in asynchronous contexts. A secondary goal of this paper is to present several pragmatic strategies for improving meaningful interactions in WBLEs on the basis of a review of relevant research literature.
Augment delay tolerant networking routing to extend wireless network coverage

Cellular networks and Wi-Fi provide range of wireless communication services. They are the practical wireless technologies for domestic and business wireless users currently. However, base station (BS)/access point (AP) may fail in disasters. This failure problem may cause part of users not able to communicate. To solve this problem, one proposed solution is to let users in failure caused coverage hole self-organize to communicate to each other or to functional BS/AP. Delay Tolerate Networking (DTN) is one of such user self-organization technologies. This paper designs and evaluates geographic binary spray and wait routing algorithm (G-BSW) in DTN to let users find routes to close BSs/APs. Meanwhile, BS/AP load balance can be guaranteed. G-BSW is a cooperative algorithm. It controls BSs/APs to broadcast metadata to users to let them find appropriate BS/AP. The metadata contains geographic and related routing information. Through simulation in an open source DTN simulator (ONE simulator), G-BSW is validated to improve message delivery rate, and BS/AP load balance.
Biomechanical finite element analysis of small diameter and short dental implants: extensive study of commercial implants

Abstract In recent years, mini and short dental implants have become increasingly popular as treatment alternatives for patients in whom the bone is unsuitable for a standard implant. As yet, no detailed scientific analysis of the mechanical and biomechanical impact of the reduced diameter and length of these implants has been published. We analysed 21 commercially available implants (13 mini, eight short) with respect to material behaviour and load transfer to the alveolar bone, using finite element (FE) analysis. Following μCT scanning and geometry reconstruction, FE models of mini implants and short implants were inserted into idealised bone segments. Mini implants were analysed in the anterior mandibular jaw region at a force of 150 N under immediate loading, using a contact analysis in the FE software package Marc Mentat 2007. Short implants were inserted in posterior bone segments and analysed in the osseointegrated state at an occlusal force of 300 N. Von Mises stresses (up to 1150 MPa) in mini implants partly exceeded the ultimate strength. Implant diameter and geometry had a pronounced effect on stresses in the cortical plate (up to 266 MPa). Strains in spongy bone and stresses in cortical bone around short implants were markedly increased compared to those in standard implants. An increased risk of bone damage or implant failure may be assumed in critical clinical situations.
YAFA-SOA: A GA-Based Optimizer for Optimizing Security and Cost in Service Compositions

This paper studies heuristic search-based optimization of service compositions. We have investigated applying Genetic Algorithms (GA) to optimize service-oriented architectures (SOA) in terms of security goals and cost, we help software Engineers to map the optimized service composition to the business process model based on security and cost. Service composition security risk is measured by implementing the aggregation rules from the local security risk values of the aggregated services in the composition. We adapt the DREAD model for Security risk assessment by suggesting new categorizations for calculating DREAD factors based on a proposed service structure and service attributes. We implemented the YAFA-SOA Optimizer as an extension of an existing GA implementation to solve multi-objective optimization problems for varying number of objectives in the context of SOA. We evaluated the tool in a case study. The study results show that applying multi-objective GA is feasible to find the optimized security and cost in SOA-based systems. We were able to approve that adding security services to the generated composition reduces the risk severity of the generated composition and enhances its security in terms of confidentiality, integrity and availability (CIA). We found that the generated service composition risk severity is less than 0.5, which matches the validation results obtained from a security expert.
Failure Dependent Reliability Analysis for Component Based Software Systems

Component Based Software systems (CBSSs) are being widely used because of their various advantages. Reliability of these systems is an important issue to be focused. The approaches which have been proposed so far, does not consider that the failure of one component depend on another and also assume that each failure affects equally to the overall system while practically it is not so. The failure of one component depends on other and also each kind of failure have their different impacts on overall system. This paper presents a new and enhanced approach for Reliability analysis of CBSSs, that will give more accurate reliability prediction than the approaches being proposed so far by taking into account the facts that the component failure affects other components as well and also that the different failure have their different impact on overall system.
d-Amino Acids Indirectly Inhibit Biofilm Formation in Bacillus subtilis by Interfering with Protein Synthesis

ABSTRACT The soil bacterium Bacillus subtilis forms biofilms on surfaces and at air-liquid interfaces. It was previously reported that these biofilms disassemble late in their life cycle and that conditioned medium from late-stage biofilms inhibits biofilm formation. Such medium contained a mixture of d-leucine, d-methionine, d-tryptophan, and d-tyrosine and was reported to inhibit biofilm formation via the incorporation of these d-amino acids into the cell wall. Here, we show that l-amino acids were able to specifically reverse the inhibitory effects of their cognate d-amino acids. We also show that d-amino acids inhibited growth and the expression of biofilm matrix genes at concentrations that inhibit biofilm formation. Finally, we report that the strain routinely used to study biofilm formation has a mutation in the gene (dtd) encoding d-tyrosyl-tRNA deacylase, an enzyme that prevents the misincorporation of d-amino acids into protein in B. subtilis. When we repaired the dtd gene, B. subtilis became resistant to the biofilm-inhibitory effects of d-amino acids without losing the ability to incorporate at least one noncanonical d-amino acid, d-tryptophan, into the peptidoglycan peptide side chain. We conclude that the susceptibility of B. subtilis to the biofilm-inhibitory effects of d-amino acids is largely, if not entirely, due to their toxic effects on protein synthesis.
Efficiently tracking application interactions using lightweight virtualization

In this paper, we propose a general-purpose framework that harnesses the power of lightweight virtualization to track applications interactions in a scalable an efficient manner. Our goal is to use our framework for application auditing, intrusion detection, analysis, and system recovery from both malicious attacks and programmatic faults. In our framework, we construct each virtualized environment (VE) in a novel way that limits the scope and type of application events that need to be monitored. Our approach maintains the VE and system integrity, having as primarily focused on the interactions among VEs and system resources including the file system, memory, and network. Only events that are pertinent to the integrity of an application and its interactions with the operating system are recorded. We attempt to minimize the system overhead both in terms of system events we have to store and the resources required. Even though we cannot provide application replay, we keep enough information for a wide range of other uses including system recovery and information tracking among others. As a proof of concept, we have implemented a prototype based on OpenVZ[35], a lightweight virtualization tool. Our preliminary results show that, compared to state-of-the-art event recording systems, we can reduce the amount of event recorded per application by almost an order of magnitude.
Transcriptional Activation of the mrkA Promoter of the Klebsiella pneumoniae Type 3 Fimbrial Operon by the c-di-GMP-Dependent MrkH Protein

The Gram-negative bacterial pathogen Klebsiella pneumoniae forms biofilms to facilitate colonization of biotic and abiotic surfaces. The formation of biofilms by K. pneumoniae requires the expression of type 3 fimbriae: elongate proteinaceous filaments extruded by a chaperone-usher system in the bacterial outer membrane. The expression of the mrkABCDF cluster that encodes this fimbrial system is strongly positively regulated by MrkH, a transcriptional activator that responds to the second messenger, c-di-GMP. In this study, we analyzed the mechanism by which the MrkH protein activates transcriptional initiation from the mrkA promoter. A mutational analysis supported by electrophoretic mobility shift assays demonstrated that a 12-bp palindromic sequence (the MrkH box) centered at −78.5 is the binding site of MrkH. Deletion of half a turn, but not a full turn, of DNA located between the MrkH box and the mrkA promoter destroyed the ability of MrkH to activate mrkA transcription. In addition, a 10-bp AT-rich sequence (the UP element) centered at −63.5 contributed significantly to MrkH-dependent mrkA transcription. In vivo analysis of rpoA mutants showed that the R265 and E273 determinants in the C-terminal domain of RNA polymerase α subunit are needed for MrkH-mediated activation of mrkA transcription. Furthermore, results from mutagenesis of the mrkH gene suggest that the N-terminal region of the protein is involved in transcriptional activation. Taken together, our results suggest that MrkH activates mrkA expression by interacting directly with RNA polymerase, to overcome the inefficient transcriptional initiation caused by the presence of defective core promoter elements.
Female Drinking From Young Adolescence to Middle Age: A Prospective Longitudinal Study

This study aimed at describing female drinking from young adolescence to middle age in a female Swedish community cohort (N = 238). Different aspects of alcohol habits were assessed at the ages of 14, 27, and 43, and the analyses focused on stability and change over this time. The results showed that large variations in alcohol habits over the life course were normally occurring phenomena. Furthermore, advanced drinking habits were neither necessary nor sufficient for developing heavy drinking or alcohol-related symptoms in adult age. The developmental patterns found in this study resembled the developmental patterns earlier described in male cohorts.
In vivo topical EPR spectroscopy and imaging of nitroxide free radicals and polynitroxyl‐albumin

Piperidine nitroxides have considerable clinical potential, both as antioxidant therapeutic compounds and contrast agents in magnetic resonance imaging. However, their development has thus far been limited by their rapid bioreduction in vivo. Recently, it was reported that polynitroxyl albumin (PNA) can reverse the bioreduction of the reduced 4‐hydroxy‐2,2,6,6‐tetramethylpiperidine‐N‐oxyl (Tempol) in the rat heart, enabling the performance of high resolution EPR imaging for prolonged time (Kuppusamy et al., Biochemistry 35, 7051–7057 (1996)). In this report, the efficacy of PNA in maintaining Tempol concentrations in vivo in mice was demonstrated, using L‐band (1.25 GHz) EPR spectroscopy and imaging. The EPR signal of intravenous Tempol had a half‐life of 1.0 ± 0.2 min and became undetectable within 6 min. Subcutaneous Tempol, however, decayed at a slower rate (half‐life, 5.0 ± 0.5 min) suggesting that Tempol had been bioreduced to the corresponding hydroxylamine form, Tempol‐H. Subcutane‐ously injected PNA restored 20% of the Tempol signal in the vicinity of the PNA deposit. In vivo topical EPR imaging demonstrated that the Tempol signal was restored at the site of PNA injection, but not at locations remote from the PNA injection site. The ability of PNA to maintain Tempol in its paramagnetic state in vivo should enable a wide range of therapeutic and diagnostic applications of piperidinyl nitroxides.
Intergenerational learning in a teacher education context: the Jared Phenomenon

While student teachers have essentially unfettered access to the expertise of university instructors and practicum supervisors during their teacher education program, this study explores the potential of employing recent graduates as a source of expertise that current student teachers might draw upon during their program. Over the course of three years, the authors employed recent graduates to facilitate instruction in an experimental 12-month after-degree BEd option at the University of British Columbia. Through the use of surveys and interviews, the authors demonstrate that graduate involvement is a special case of intergenerational learning that they refer to as the Jared Phenomenon. Their analysis offers five characteristics that define the phenomenon, outlines the contexts in which this definition is applicable, and points to a set of dilemmas that arise from its application. They recommend the judicious use of recent graduates as instructors for current students as an important and underutilised resource in teacher education.
Trust network inference for online rating data using generative models

In an online rating system, raters assign ratings to objects contributed by other users. In addition, raters can develop trust and distrust on object contributors depending on a few rating and trust related factors. Previous study has shown that ratings and trust links can influence each other but there has been a lack of a formal model to relate these factors together. In this paper, we therefore propose Trust Antecedent Factor (TAF) Model, a novel probabilistic model that generate ratings based on a number of rater's and contributor's factors. We demonstrate that parameters of the model can be learnt by Collapsed Gibbs Sampling. We then apply the model to predict trust and distrust between raters and review contributors using a real data-set. Our experiments have shown that the proposed model is capable of predicting both trust and distrust in a unified way. The model can also determine user factors which otherwise cannot be observed from the rating and trust data.
Chondrocytic ephrin B2 promotes cartilage destruction by osteoclasts in endochondral ossification

The majority of the skeleton arises by endochondral ossification, whereby cartilaginous templates expand and are resorbed by osteoclasts then replaced by osteoblastic bone formation. Ephrin B2 is a receptor tyrosine kinase expressed by osteoblasts and growth plate chondrocytes that promotes osteoblast differentiation and inhibits osteoclast formation. We investigated the role of ephrin B2 in endochondral ossification using Osx1Cre-targeted gene deletion. Neonatal Osx1Cre. Efnb2Δ/Δ mice exhibited a transient osteopetrosis demonstrated by increased trabecular bone volume with a high content of growth plate cartilage remnants and increased cortical thickness, but normal osteoclast numbers within the primary spongiosa. Osteoclasts at the growth plate had an abnormal morphology and expressed low levels of tartrate-resistant acid phosphatase; this was not observed in more mature bone. Electron microscopy revealed a lack of sealing zones and poor attachment of Osx1Cre. Efnb2Δ/Δ osteoclasts to growth plate cartilage. Osteoblasts at the growth plate were also poorly attached and impaired in their ability to deposit osteoid. By 6 months of age, trabecular bone mass, osteoclast morphology and osteoid deposition by Osx1Cre. Efnb2Δ/Δ osteoblasts were normal. Cultured chondrocytes from Osx1Cre. Efnb2Δ/Δ neonates showed impaired support of osteoclastogenesis but no significant change in Rankl (Tnfsf11) levels, whereas Adamts4 levels were significantly reduced. A population of ADAMTS4+ early hypertrophic chondrocytes seen in controls was absent from Osx1Cre. Efnb2Δ/Δ neonates. This suggests that Osx1Cre-expressing cells, including hypertrophic chondrocytes, are dependent on ephrin B2 for their production of cartilage-degrading enzymes, including ADAMTS4, and this might be required for attachment of osteoclasts and osteoblasts to the cartilage surface during endochondral ossification. Summary: During bone formation in neonatal mice, chondrocytic expression of the receptor tyrosine kinase Ephrin B2 regulates cartilage degradation and subsequent osteoclastic destruction of the cartilage matrix.
Adaptive Neural Networks Prescribed Performance Control Design for Switched Interconnected Uncertain Nonlinear Systems

In this paper, an adaptive neural net- works (NNs)-based decentralized control scheme with the prescribed performance is proposed for uncertain switched nonstrict-feedback interconnected nonlinear systems. It is assumed that nonlinear interconnected terms and nonlinear functions of the concerned systems are unknown, and also the switching signals are unknown and arbitrary. A linear state estimator is constructed to solve the problem of unmeasured states. The NNs are employed to approximate unknown interconnected terms and nonlinear functions. A new output feedback decentralized control scheme is developed by using the adaptive backstepping design technique. The control design problem of nonlinear interconnected switched systems with unknown switching signals can be solved by the proposed scheme, and only a tuning parameter is needed for each subsystem. The proposed scheme can ensure that all variables of the control systems are semi-globally uniformly ultimately bounded and the tracking errors converge to a small residual set with the prescribed performance bound. The effectiveness of the proposed control approach is verified by some simulation results.