Looking at both sides of relationship dynamics in virtual communities: A social exchange theoretical lens

This study draws on social exchange theory to investigate the relationship dynamics of the member–community dyad in virtual community settings. Using a longitudinal design and multiple measurement sources, the findings indicate that social and task communication styles have unique effects on members’ community commitment velocity, which in turn influences member gratitude and entitlement behaviors. A moderated path analysis demonstrates that the effects of social and task communication styles on community commitment velocity are both positively moderated by attachment anxiety and attachment avoidance. It also reveals that members’ level of popularity augments the influence of community commitment velocity on member entitlement behavior

Morphological and Mechanical Biomimetic Bone Structures

© 2016 American Chemical Society. Cortical bone is an example of a mineralized tissue containing a compositional distribution of hard and soft phases in 3-dimensional space for mechanical function. X-ray computed tomography (XCT) is able to describe this compositional and morphological complexity but methods to provide a physical output with comparable mechanical function is lacking. A workflow is presented here to establish a method of using high contrast XCT to establish a virtual model of cortical bone that is manufactured using a multiple material capable 3D printer. Resultant 3D printed structures were produced based on more and less remodelled bone designs exhibiting a range of secondary osteon density. Variation in resultant mechanical properties of the 3D printed composite structures for each bone design was achieved using a combination of material components and reasonable prediction of elastic modulus provided using a Hashin-Shtrikman approach. The ability to 3D print composite structures using high contrast XCT to distinguish between compositional phases in a biological structure promises improved anatomical models as well as next-generation mechano-mimetic implants

Inhibitory effects of inhaled complex traditional Chinese medicine on early and late asthmatic responses induced by ovalbumin in sensitized guinea pigs

<p>Abstract</p> <p>Background</p> <p>Many formulae of traditional Chinese medicines (TCMs) have been used for antiasthma treatment dating back many centuries. There is evidence to suggest that TCMs are effective as a cure for this allergenic disease administered via gastric tubes in animal studies; however, their efficacy, safety and side effects as an asthmatic therapy are still unclear.</p> <p>Methods</p> <p>In this study, guinea pigs sensitized with ovalbumin (OVA) were used as an animal model for asthma challenge, and the sensitization of animals by bronchial reactivity to methacholine (Mch) and the IgE concentration in the serum after OVA challenge were estimated. Complex traditional Chinese herbs (CTCM) were administered to the animals by nebulization, and the leukocytes were evaluated from bronchoalveolar lavage fluid (BALF).</p> <p>Results</p> <p>The results showed that inhalation of CTCM could abolish the increased lung resistance (13-fold increase) induced by challenge with OVA in the early asthmatic response (EAR), reducing to as low as baseline (1-fold). Moreover, our results indicated higher IgE levels (range, 78-83 ng/ml) in the serum of sensitized guinea pigs than in the unsensitized controls (0.9 ± 0.256 ng/ml). In addition, increased total leukocytes and higher levels of eosinophils and neutrophils were seen 6 hours after challenge, and the increased inflammatory cells were reduced by treatment with CTCM inhalation. The interleukin-5 (IL-5) level in BALF was also reduced by CTCM.</p> <p>Conclusion</p> <p>Our findings indicate a novel method of administering traditional Chinese medicines for asthma treatment in an animal model that may be more effective than traditional methods.</p

Evaluation of the nasal mucociliary transport rate by rhinoscintigraphy before and after surgery in patients with deviated nasal septum

In this study, we have investigated the effect of nasal septal deviation (NSD) on nasal mucociliary activity and how does a septoplasty operation affecs the nasal mucociliary transport rate in the first and third months during the post-operative period. Twenty-two patients who were diagnosed with NSD and 22 healthy controls were studied using rhinoscintigraphy with Tc-99m-macroaggregated albumin (Tc-99m-MAA). On each case, the nasal mucociliary transport rate (NMTR) was measured pre-operatively only on five cases, on the first and third months of post-operative period. The NMTRs of patients with a deviated septum were significantly lower than the NMTRs of the healthy controls on both the convex and concave sides. Significant improvement was observed in the first post-operative month. On the concave and convex sides, the average postop third month post-operative NMTR value was higher than the first month post-operative NMTR values. It was concluded that the septoplasty operation improves reduced NMTRs after surgery. The effect of nasal surgery on nasal mucociliary activity may be more accurately evaluated in the third month than the first month of post-operative period

Expression and trans-specific polymorphism of self-incompatibility RNases in Coffea (Rubiaceae)

Self-incompatibility (SI) is widespread in the angiosperms, but identifying the biochemical components of SI mechanisms has proven to be difficult in most lineages. Coffea (coffee; Rubiaceae) is a genus of old-world tropical understory trees in which the vast majority of diploid species utilize a mechanism of gametophytic self-incompatibility (GSI). The S-RNase GSI system was one of the first SI mechanisms to be biochemically characterized, and likely represents the ancestral Eudicot condition as evidenced by its functional characterization in both asterid (Solanaceae, Plantaginaceae) and rosid (Rosaceae) lineages. The S-RNase GSI mechanism employs the activity of class III RNase T2 proteins to terminate the growth of "self" pollen tubes. Here, we investigate the mechanism of Coffea GSI and specifically examine the potential for homology to S-RNase GSI by sequencing class III RNase T2 genes in populations of 14 African and Madagascan Coffea species and the closely related self-compatible species Psilanthus ebracteolatus. Phylogenetic analyses of these sequences aligned to a diverse sample of plant RNase T2 genes show that the Coffea genome contains at least three class III RNase T2 genes. Patterns of tissue-specific gene expression identify one of these RNase T2 genes as the putative Coffea S-RNase gene. We show that populations of SI Coffea are remarkably polymorphic for putative S-RNase alleles, and exhibit a persistent pattern of trans-specific polymorphism characteristic of all S-RNase genes previously isolated from GSI Eudicot lineages. We thus conclude that Coffea GSI is most likely homologous to the classic Eudicot S-RNase system, which was retained since the divergence of the Rubiaceae lineage from an ancient SI Eudicot ancestor, nearly 90 million years ago.United States National Science Foundation [0849186]; Society of Systematic Biologists; American Society of Plant Taxonomists; Duke University Graduate Schoolinfo:eu-repo/semantics/publishedVersio

Variable selection for large p small n regression models with incomplete data: Mapping QTL with epistases

<p>Abstract</p> <p>Background</p> <p>Identifying quantitative trait loci (QTL) for both additive and epistatic effects raises the statistical issue of selecting variables from a large number of candidates using a small number of observations. Missing trait and/or marker values prevent one from directly applying the classical model selection criteria such as Akaike's information criterion (AIC) and Bayesian information criterion (BIC).</p> <p>Results</p> <p>We propose a two-step Bayesian variable selection method which deals with the sparse parameter space and the small sample size issues. The regression coefficient priors are flexible enough to incorporate the characteristic of "large <it>p </it>small <it>n</it>" data. Specifically, sparseness and possible asymmetry of the significant coefficients are dealt with by developing a Gibbs sampling algorithm to stochastically search through low-dimensional subspaces for significant variables. The superior performance of the approach is demonstrated via simulation study. We also applied it to real QTL mapping datasets.</p> <p>Conclusion</p> <p>The two-step procedure coupled with Bayesian classification offers flexibility in modeling "large p small n" data, especially for the sparse and asymmetric parameter space. This approach can be extended to other settings characterized by high dimension and low sample size.</p

Systematic Reviews and Meta-Analyses of the Procedure-specific Risks of Thrombosis and Bleeding in General Abdominal, Colorectal, Upper Gastrointestinal, and Hepatopancreatobiliary Surgery

\ua9 2024 Lippincott Williams and Wilkins. All rights reserved.Objective: To provide procedure-specific estimates of symptomatic venous thromboembolism (VTE) and major bleeding after abdominal surgery. Background: The use of pharmacological thromboprophylaxis represents a trade-off that depends on VTE and bleeding risks that vary between procedures; their magnitude remains uncertain. Methods: We identified observational studies reporting procedure-specific risks of symptomatic VTE or major bleeding after abdominal surgery, adjusted the reported estimates for thromboprophylaxis and length of follow-up, and estimated cumulative incidence at 4 weeks postsurgery, stratified by VTE risk groups, and rated evidence certainty. Results: After eligibility screening, 285 studies (8,048,635 patients) reporting on 40 general abdominal, 36 colorectal, 15 upper gastrointestinal, and 24 hepatopancreatobiliary surgery procedures proved eligible. Evidence certainty proved generally moderate or low for VTE and low or very low for bleeding requiring reintervention. The risk of VTE varied substantially among procedures: in general abdominal surgery from a median of &lt;0.1% in laparoscopic cholecystectomy to a median of 3.7% in open small bowel resection, in colorectal from 0.3% in minimally invasive sigmoid colectomy to 10.0% in emergency open total proctocolectomy, and in upper gastrointestinal/hepatopancreatobiliary from 0.2% in laparoscopic sleeve gastrectomy to 6.8% in open distal pancreatectomy for cancer. Conclusions: VTE thromboprophylaxis provides net benefit through VTE reduction with a small increase in bleeding in some procedures (eg, open colectomy and open pancreaticoduodenectomy), whereas the opposite is true in others (eg, laparoscopic cholecystectomy and elective groin hernia repairs). In many procedures, thromboembolism and bleeding risks are similar, and decisions depend on individual risk prediction and values and preferences regarding VTE and bleeding

Assessing the relationship between bpm maturity and the success of organizations

Pinto, J., & dos Santos, V. D. (2020). Assessing the relationship between bpm maturity and the success of organizations. In R. Silhavy (Ed.), Applied Informatics and Cybernetics in Intelligent Systems: Proceedings of the 9th Computer Science On-line Conference, CSOC 2020 (pp. 108-126). (Advances in Intelligent Systems and Computing; Vol. 1226 AISC). Springer. https://doi.org/10.1007/978-3-030-51974-2_10For the past decades, organizations have been investing heavily in BPM projects in the hope of improving their competitive advantage in an increasingly complex environment. However, although it is believed that the higher the level of BPM maturity the greater the success of the organization, experience shows that this relationship is not always possible to prove. The purpose of this study is to help clarify the relationship between the level of BPM maturity and the success of an organization. This was done through the implementation of a case study-based research within a global company, focusing on the shared services organization. An analysis of the existing BPM maturity models and its level of coverage of BPM core areas was conducted to select the most suitable BPM maturity model to conduct the assessment of the current BPM maturity level. It was also established a framework to characterize the success of an organization. These two inputs, along with information gathered to understand implemented process improvements, were the basis for conducting the research. Results show a successful organization, with a high maturity level according to the BPM OMG maturity model, that has been investing in continually improving its processes with a strong focus on digital transformation. The identified benefits from a high level of BPM maturity, namely improved productivity, cost reduction, error & risk prevention, higher agility, employee upskilling and knowledge retention, were shown to have a positive influence in the majority of the dimensions used to characterize the success of the organization.authorsversionpublishe

Lattice Boltzmann simulations of soft matter systems

This article concerns numerical simulations of the dynamics of particles immersed in a continuum solvent. As prototypical systems, we consider colloidal dispersions of spherical particles and solutions of uncharged polymers. After a brief explanation of the concept of hydrodynamic interactions, we give a general overview over the various simulation methods that have been developed to cope with the resulting computational problems. We then focus on the approach we have developed, which couples a system of particles to a lattice Boltzmann model representing the solvent degrees of freedom. The standard D3Q19 lattice Boltzmann model is derived and explained in depth, followed by a detailed discussion of complementary methods for the coupling of solvent and solute. Colloidal dispersions are best described in terms of extended particles with appropriate boundary conditions at the surfaces, while particles with internal degrees of freedom are easier to simulate as an arrangement of mass points with frictional coupling to the solvent. In both cases, particular care has been taken to simulate thermal fluctuations in a consistent way. The usefulness of this methodology is illustrated by studies from our own research, where the dynamics of colloidal and polymeric systems has been investigated in both equilibrium and nonequilibrium situations.Comment: Review article, submitted to Advances in Polymer Science. 16 figures, 76 page