Spatial trends of noncollinear exchange coupling mediated by itinerant carriers with different Fermi surfaces

We study the exchange coupling mediated by itinerant carriers with spin-orbit interaction by both analytic and numeric approaches. The mediated exchange coupling is noncollinear and its spatial trends depend on the Fermi-surface topology of the itinerant carriers. Taking Rashba interaction as an example, the exchange coupling is similar to the conventional Ruderman-Kittel-Kasuya-Yosida type in weak coupling. On the other hand, in the strong coupling, the spiral interaction dominates. In addition, inclusion of finite spin relaxation always makes the noncollinear spiral exchange interaction dominant. Potential applications of our findings are explained and discussed

Towards a comprehensive understanding of design sketch - a literature review of design sketch taxonomy and considerations for future research / Min Hua ... [et. al]

Taxonomy is an important approach to characterize the roles of the sketch in design. Design researchers have made various attempts to classify design sketches. However, despite the extensive literature on the subject, the roles that sketch play in design are still not fully understood, especially those changing ones in today’s design context due to the development of CAD/ sketching software. This study performed a literature review of the design sketch taxonomies published over the last thirty years. The objective is to understand the major drawbacks that limit their effective implementation in the research of design sketch. This study developed a Generic Design Process model and proposed criteria for accessing design sketch taxonomies. This study has found that to achieve a comprehensive understanding of design sketch, many taxonomies have limitations in describing the whole design process and revealing the sub-functions of design sketch, which feature a lack of both integrity and accuracy. In addition, most of the taxonomies overlook the importance of non-working sketch, which is also an obstacle for its implementation in the field

Friezes with coefficients

For a cluster algebra $\mathcal{A}$ over $\mathbb{Q}$ of geometric type, we define a $\textit{frieze}$ of $\mathcal{A}$ to be a $\mathbb{Q}$-algebra homomorphism from $\mathcal{A}$ to $\mathbb{Q}$ that takes positive integer values on all cluster variables and all frozen variables. We present some basic facts on friezes, including frieze testing criteria, the notion of $\textit{frieze points}$ when $\mathcal{A}$ is finitely generated, and pullbacks of friezes under certain $\mathbb{Q}$-algebra homomorphisms. For cluster algebras with acyclic seeds, we introduce $\textit{frieze patterns with coefficients}$ and we give a sufficient condition for frieze patterns to be equivalent to friezes. For the special cases when $\mathcal{A}$ has an acyclic seed with either trivial coefficients, principal coefficients, or what we call the $\textit{BFZ coefficients}$ (named after A. Berenstein, S. Fomin, and A. Zelevinsky), we identify frieze points of $\mathcal{A}$ both geometrically as certain positive integral points in explicitly described affine varieties and Lie theoretically (in the finite case) in terms of reduced double Bruhat cells and generalized minors on the associated semi-simple Lie groups.Comment: 47 page

In vitro culture method of powdery mildew (Oidium heveae Steinmann) of Hevea brasiliensis

A method for culturing powdery mildew (Oidium heveae) from isolated leaves of Hevea brasiliensis was evaluated, which included three steps: Leaves and fungi selection, nutrient solution and culture dish  preparation, fungi inoculation and culture. The culture time and produced conidia number were considered as decision index. We tested the influence of micro components of nutrient solution including 6-benzylaminopurine (6-BA), salicylic acid (SA) and vitamin C (VC) and evaluated the culture difference of various leaf phenological phases and rubber tree clones. The results show that the longest culture time of isolated leaves emerged on modified Murashige and Skoog (MS) macro elements with 4 mg/L 6-BA, 20 mg/L SA, 1 mg/L VC. The colour phase leaf was the preferable choice for culturing average 15 to 16 days and producing 3.2222 × 106 mL-1 conidia. The culture effects of using various rubber clones were different and higher resistance clones cultured less conidia. The method leading to mass production of powdery mildew was simple using a climate incubator to resolve problems linked to season and space limitation and preservation of powdery mildew. This method could improve rubber resistance breeding process.Key words: Hevea brasiliensis, Oidium heveae, in vitro culture, nutrient solution, phenological phase

Towards harmonious East-West educational partnerships: a study of cultural differences between Taiwanese and Norwegian engineering students

The collaboration activities between educational institutions in the East and the West are on the increase as an increasingly globalized economy requires graduates to have the skills to work across cultural divides. Such collaborations are difficult and require patience. One challenge is that students or teachers may have misconceptions about aspects of the other culture that may cause problems. This study sets out to identify what values students in typical Eastern and Western societies associate with a good student, good student behavior, good teachers and good lectures with the purpose to identify discrepancies. This study is based on the results of a pair-wise ranking questionnaire completed by 233 Taiwanese and Norwegian students of both engineering and non-technical subjects. The results confirm some established beliefs regarding culturally related differences. However, several issues were found to be culturally neutral, and cultural differences were identified for several issues that were predicted to be culturally neutral. The results of this study may be useful to educators involved in East–West internationalization

Studies or Leisure? : a Cross-cultural Comparison of Taiwanese and Norwegian Engineering Students' Preferences for University Life

An insight into students' preferences and expectations of life at university is useful when trying to understand drop-out percentages and design study programs, especially in the global competition for students. This study focuses on Taiwanese and Norwegian students' preferences for life and activities at university. Hofstede's model was used to predict culture-related differences. A pairwise decision questionnaire was used to conduct measurements. A universal trend is that teamwork was considered most important, and teachers were considered to be less important. The most noticeable culture differences were that Taiwanese students preferred non-curricular values and Norwegian students preferred curricular values. The study discipline had little impact on students' preferences

Combined effects of permeability and fluid saturation on seismic wave dispersion and attenuation in partially-saturated sandstone

Knowledge of dispersion and attenuation is essential for better reservoir characterization and hydrocarbon identification. However, limited by reliable laboratory data at seismic frequency bands, the roles of rock and fluid properties in inducing dispersion and attenuation are still poorly understood. Here we perform a series of laboratory measurements on Bentheimer and Bandera sandstone under both vacuum-dry and partially water-saturated conditions at frequencies ranging from 2 to 600 Hz. At vacuum-dry conditions, the bulk dispersion and attenuation in Bandera sandstone with more clay contents are distinctly larger than those in Bentheimer sandstone, suggesting clay contents might contribute to the inelasticity of the rock frame. The partially water-saturated results show the combined effects of rock permeability and fluid saturation on bulk dispersion and attenuation. Even a few percent of gas can substantially dominate the pore-fluid relaxation by providing a quick and short communication path for pore pressure gradients. The consequent bulk dispersion and attenuation are negligible. Only as the samples are approaching fully water-saturated conditions, rock permeability begins to play an essential role in the pore-fluid relaxation. For Bandera sandstone with lower permeability, a partially relaxed status of pore fluids is achieved when the gas saturation is lower than 5%, accompanied by significant attenuation and dispersion.Cited as: Wei, Q., Wang, Y., Han, D., Sun, M., Huang, Q. Combined effects of permeability and fluid saturation on seismic wave dispersion and attenuation in partially-saturated sandstone. Advances in Geo-Energy Research, 2021, 5(2): 181-190, doi: 10.46690/ager.2021.02.0

N-(1-Naphth­yl)acetoacetamide

The title compound, C14H13NO2, exists in the keto form. An N—H⋯O hydrogen bond helps to establish the packing

Infectomic Analysis of Gene Expression Profiles of Human Brain Microvascular Endothelial Cells Infected with Cryptococcus neoformans

In order to dissect the pathogenesis of Cryptococcus neoformans meningoencephalitis, a genomic survey of the changes in gene expression of human brain microvascular endothelial cells infected by C. neoformans was carried out in a time-course study. Principal component analysis (PCA) revealed significant fluctuations in the expression levels of different groups of genes during the pathogen-host interaction. Self-organizing map (SOM) analysis revealed that most genes were up- or downregulated 2 folds or more at least at one time point during the pathogen-host engagement. The microarray data were validated by Western blot analysis of a group of genes, including β-actin, Bcl-x, CD47, Bax, Bad, and Bcl-2. Hierarchical cluster profile showed that 61 out of 66 listed interferon genes were changed at least at one time point. Similarly, the active responses in expression of MHC genes were detected at all stages of the interaction. Taken together, our infectomic approaches suggest that the host cells significantly change the gene profiles and also actively participate in immunoregulations of the central nervous system (CNS) during C. neoformans infection

Lipid raft/caveolae signaling is required for Cryptococcus neoformans invasion into human brain microvascular endothelial cells

<p>Abstract</p> <p>Background</p> <p><it>Cryptococcus neoformans </it>has a predilection for central nervous system infection. <it>C. neoformans </it>traversal of the blood brain barrier, composed of human brain microvascular endothelial cells (HBMEC), is the crucial step in brain infection. However, the molecular mechanism of the interaction between <it>Cryptococcus neoformans </it>and HBMEC, relevant to its brain invasion, is still largely unknown.</p> <p>Methods</p> <p>In this report, we explored several cellular and molecular events involving the membrane lipid rafts and caveolin-1 (Cav1) of HBMEC during <it>C. neoformans </it>infection. Immunofluorescence microscopy was used to examine the roles of Cav1. The knockdown of Cav1 by the siRNA treatment was performed. Phosphorylation of Cav1 relevant to its invasion functions was investigated.</p> <p>Results</p> <p>We found that the host receptor CD44 colocalized with Cav1 on the plasma membrane, and knockdown of Cav1 significantly reduced the fungal ability to invade HBMEC. Although the CD44 molecules were still present, HBMEC membrane organization was distorted by Cav1 knockdown. Concomitantly, knockdown of Cav1 significantly reduced the fungal crossing of the HBMEC monolayer <it>in vitro</it>. Upon <it>C. neoformans </it>engagement, host Cav1 was phosphorylated in a CD44-dependent manner. This phosphorylation was diminished by filipin, a disrupter of lipid raft structure. Furthermore, the phosphorylated Cav1 at the lipid raft migrated inward to the perinuclear localization. Interestingly, the phospho-Cav1 formed a thread-like structure and colocalized with actin filaments but not with the microtubule network.</p> <p>Conclusion</p> <p>These data support that <it>C. neoformans </it>internalization into HBMEC is a lipid raft/caveolae-dependent endocytic process where the actin cytoskeleton is involved, and the Cav1 plays an essential role in <it>C. neoformans </it>traversal of the blood-brain barrier.</p