3,101 research outputs found
Investigating the Development of Work-oriented Groups in an e-Learning Environment
[[abstract]]In this study, we have investigated developmental patterns of virtual groups in the e-learning environment. Our findings suggest that for virtual groups formed for the purpose of e-learning, dependency and inclusion characterize the initial stage of group development, as such characteristics reinforce cooperative relationships and help to build a stronger social bond among group members. This is followed by the second stage, swift work, which enables participants to labor as a team and facilitates continual collaboration among members. However, the third stage, conflict, is inevitable, as conflicts provide important diagnostic evidence for each member to assess and adjust his or her values and preference. Finally, by overcoming conflicts, partners build strong bonding, which fosters intimate communication and provides many opportunities for frequent interactions that demonstrate concern and desire to satisfy the needs and wishes of one another. Our finding suggests that initial active dependency interactions in the first period provide a sense of coherence. Accordingly, the instructor of a virtual learning system should encourage learners to express their concern for one another in order quickly to build strong norms. In addition, as work intensifies, the instructor could aim to support both the effective interaction channels of groups as well as their task-focused activities. Finally, to improve members’ involvement and information sharing, the instructor could provide feedback to groups regarding their level of interactivity and encourage members to remind each other about the quality and quantity of individual contribution.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]SSCI[[booktype]]紙本[[booktype]]電子版[[countrycodes]]NZ
Enhanced Early Galaxy Formation in JWST from Axion Dark Matter?
We demonstrate that enhanced early galaxy formation can generically arise in
axion-like particle (ALP) dark matter (DM) theories with the kinetic
misalignment mechanism, potentially addressing the excess recently observed by
the James Webb Space Telescope (JWST), while being consistent with existing
constraints. We identify viable parameter regions with the ALP mass in the
range of . In addition, we show that the
ALP parameter regions of interest can lead to intriguing complementary
signatures in the small-scale structure of DM halos and existing experimental
searches for ALPs.Comment: 6 pages, 5 figure
Application of the SUSTAIN Model to a Watershed-Scale Case for Water Quality Management
[[abstract]]Low impact development (LID) is a relatively new concept in land use management that aims to maintain hydrological conditions at a predevelopment level without deteriorating water quality during land development. The United States Environmental Protection Agency (USEPA) developed the System for Urban Stormwater Treatment and Analysis Integration model (SUSTAIN) to evaluate the performance of LID practices at different spatial scales; however, the application of this model has been limited relative to LID modeling. In this study, the SUSTAIN model was applied to a Taiwanese watershed. Model calibration and verification were performed, and different types of LID facilities were evaluated. The model simulation process and the verified model parameters could be used in other cases. Four LID scenarios combining bioretention ponds, grass swales, and pervious pavements were designed based on the land characteristics. For the SUSTAIN model simulation, the results showed that pollution reduction was mainly due to water quantity reduction, infiltration was the dominant mechanism and plant interception had a minor effect on the treatment. The simulation results were used to rank the primary areas for nonpoint source pollution and identify effective LID practices. In addition to the case study, a sensitivity analysis of the model parameters was performed, showing that the soil infiltration rate was the most sensitive parameter affecting the LID performance. The objectives of the study are to confirm the applicability of the SUSTAIN model and to assess the effectiveness of LID practices in the studied watershed.[[notice]]補正完畢[[incitationindex]]SCI[[booktype]]電子
Conformational change of the AcrR regulator reveals a possible mechanism of induction
The Escherichia coli AcrR multidrug-binding protein represses transcription of acrAB and is induced by many structurally unrelated cytotoxic compounds. The crystal structure of AcrR in space group P2221 has been reported previously. This P2221 structure has provided direct information about the multidrug-binding site and important residues for drug recognition. Here, a crystal structure of this regulator in space group P31 is presented. Comparison of the two AcrR structures reveals possible mechanisms of ligand binding and AcrR regulation
CAPIH: A Web interface for comparative analyses and visualization of host-HIV protein-protein interactions
<p>Abstract</p> <p>Background</p> <p>The Human Immunodeficiency Virus type one (HIV-1) is the major causing pathogen of the Acquired Immune Deficiency Syndrome (AIDS). A large number of HIV-1-related studies are based on three non-human model animals: chimpanzee, rhesus macaque, and mouse. However, the differences in host-HIV-1 interactions between human and these model organisms have remained unexplored.</p> <p>Description</p> <p>Here we present CAPIH (Comparative Analysis of Protein Interactions for HIV-1), the first web-based interface to provide comparative information between human and the three model organisms in the context of host-HIV-1 protein interactions. CAPIH identifies genetic changes that occur in HIV-1-interacting host proteins. In a total of 1,370 orthologous protein sets, CAPIH identifies ~86,000 amino acid substitutions, ~21,000 insertions/deletions, and ~33,000 potential post-translational modifications that occur only in one of the four compared species. CAPIH also provides an interactive interface to display the host-HIV-1 protein interaction networks, the presence/absence of orthologous proteins in the model organisms in the networks, the genetic changes that occur in the protein nodes, and the functional domains and potential protein interaction hot sites that may be affected by the genetic changes. The CAPIH interface is freely accessible at <url>http://bioinfo-dbb.nhri.org.tw/capih</url>.</p> <p>Conclusion</p> <p>CAPIH exemplifies that large divergences exist in disease-associated proteins between human and the model animals. Since all of the newly developed medications must be tested in model animals before entering clinical trials, it is advisable that comparative analyses be performed to ensure proper translations of animal-based studies. In the case of AIDS, the host-HIV-1 protein interactions apparently have differed to a great extent among the compared species. An integrated protein network comparison among the four species will probably shed new lights on AIDS studies.</p
Doping and temperature dependence of electron spectrum and quasiparticle dispersion in doped bilayer cuprates
Within the t-t'-J model, the electron spectrum and quasiparticle dispersion
in doped bilayer cuprates in the normal state are discussed by considering the
bilayer interaction. It is shown that the bilayer interaction splits the
electron spectrum of doped bilayer cuprates into the bonding and antibonding
components around the point. The differentiation between the bonding
and antibonding components is essential, which leads to two main flat bands
around the point below the Fermi energy. In analogy to the doped
single layer cuprates, the lowest energy states in doped bilayer cuprates are
located at the point. Our results also show that the striking
behavior of the electronic structure in doped bilayer cuprates is intriguingly
related to the bilayer interaction together with strong coupling between the
electron quasiparticles and collective magnetic excitations.Comment: 9 pages, 4 figures, updated references, added figures and
discussions, accepted for publication in Phys. Rev.
翡翠水庫蓄水範圍保護帶設置對水庫水質改善影響
翡翠水庫係為大臺北地區民生用水重要來源,其污染來源以非點源污染為主。保護帶設置為非點源污染最佳管理作業 (BMP),也是目前翡翠水庫管理策略之一。本研究應用地理資訊系統 (GIS) 以及暴雨管理模式 (SWMM),模擬保護帶 (Buffer Strips) 設置後對翡翠水庫集水區非點源污染削減量,模擬水質項目包含懸浮固體 (SS)、總磷 (TP) 及生化需氧量 (BOD)。研究結果顯示,在蓄水範圍四周設置50 公尺保護帶時,設置保護帶的子集水區SS 輸出削減率超過80%,TP 削減率超過50%,BOD 削減率達到70%。另外利用Vollenweider 模式模擬保護帶設置對水庫水質影響,此總磷削減率最高可達6.1%。若以水庫總磷濃度10μg/L為目標值,則集水區總磷污染量尚需削減19.0%~22.2%。設置50 公尺保護帶可削減總磷每年約800 公斤,佔目標削減量1/3~1/4。除了設置保護帶外,尚需透過其他非點源污染控制措施才能達到此削減量。The Feitsui reservoir is the drinking water source for the Taipei metropolis, and nonpoint source pollution in this reservoir has been considered as an important issue. Buffer Strips are one of the best management practices (BMPs) and are used in Feitsui reservoir management. In this study, we integrate geographic information systems (GIS) and Stormwater Management Model (SWMM) to assess the effects of buffer strips in Feitsui reservoir. The major water quality items contain suspended solids (SS), total phosphorus (TP) and biochemical oxygen demand (BOD). The results show placing buffer strips 50 m in width around the reservoir can reduce 80% of SS, 50% of TP, and 70% of COD for the subwatersheds with buffer strips. In addition, the Vollenweider model is utilized to assess water quality in the reservoir and the results show that a 19-22% pollution reduction rate is required to achieve the goal of 10μg/L of TP. Buffer strips 50m in width contributed 1/3-1/4 reduction loads, which is 800 kgTP/yr. In addition to buffer strips, more BMPs are necessary in the watershed management of Feitsui reservoir
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