2,526 research outputs found
Effects of Online Learning on Student Moral Development: A Meta-analysis Based on 42 Experimental and Quasi-experimental Studies
The widespread practices of online learning have sparked increasing interest in its educational efficacy. The effects of online learning on learners’ moral development remain contentious in existing research. The purpose of this meta-analysis was to ascertain how online leaning impact students’ moral development. It included 42 experimental and quasi-experimental studies with an aggregate sample of 5303 learners after the processes of literature screening, data extraction, and risk of bias assessment. Analytical results revealed that online learning had positive effects on student moral understanding and reasoning, but no significant impact on student moral emotions and behavior. Subgroup analyses by student type, course type, online learning pattern, and involvement of interactive activity showed that there were disparities in the effect size between all subgroups and that only the moderating effect of student type on student moral reasoning was statistically significant
Modelling vibratory roller–soil system dynamics using discrete element method
A simple yet useful implementation of lumped-parameter models using the discrete element method is discussed in this paper. Lumped-parameter models are often used in the modelling of vibratory roller-soil systems owing to their ability to capture the essential features observed during roller-soil vibrations. In order to investigate the system behaviour in the event of a decoupling (loss of contact between the drum and the soil), two conditions pertaining to the transition between the contact and non-contact phases are compared in the light of simulation results. The results demonstrate significant differences in the roller-soil system behaviour based on operating conditions. One particular case provides an unrealistic estimate of the contact force, and thus may lead to an incorrect prediction of the system dynamics. Another solution, however, provides a reasonable estimate of the system dynamics and is recommended herein
The Internet: The Frontier of Cultural Soft Power in Cross-Cultural Transmission
As a significant carrier of culture and cultural products, the Internet plays a significant role in cross-cultural transmission. Within the framework of Soft Power theory, the phenomenon of cross-cultural transmission on the Internet is analyzed, and further study of its causes are conducted. Culture has become a prominent element of soft power. With globalization and consumerism as the context, cultural industry flourishes. Meanwhile, the Internet develops exponentially, becomes a powerful agent between culture and economy and performs as the frontier of cultural soft power in cross-cultural transmission.
Achieving Scalable Capacity in Wireless Mesh Networks
Wireless mesh networks play a critical role in enabling key networking
scenarios in beyond-5G (B5G) and 6G networks, including integrated access and
backhaul (IAB), multi-hop sidelinks, and V2X. However, it still poses a
challenge to deliver scalable per-node throughput via mesh networking, which
significantly limits the potential of large-scale deployment of wireless mesh
networks. Existing research has achieved per-node throughput in a dense
network, but how to achieve scalability remains an unresolved issue for an
extended wireless network where the network size increases with a constant node
density. This issue prevents a wireless mesh network from large-scale
deployment. To this end, this paper aims to develop a theoretical approach to
achieving scalable per-node throughput in wireless mesh networks. First, the
key factors that limit the per-node throughput of wireless mesh networks are
analyzed, through which two major ones are identified, i.e., link sharing and
interference. Next, a multi-tier hierarchical architecture is proposed to
overcome the link-sharing issue. The inter-tier interference under this
architecture is then mitigated by utilizing orthogonal frequency allocation
between adjacent tiers, while the intra-tier interference is reduced by
considering two specific transmission schemes, one is MIMO spatial multiplexing
with time-division, the other is MIMO beamforming. Theoretical analysis shows
that the multi-tier mesh networking architecture can achieve a per-node
throughput of in both schemes, as long as certain conditions on
network parameters including bandwidth, antenna numbers, and node numbers of
each tier are satisfied. A case study on a realistic deployment of 10,000 nodes
is then carried out, which demonstrates that a scalable throughput of
is achievable with a reasonable assumption on bandwidth and antenna
numbers.Comment: ~12pages, 4 figures, submitted to IEEE TIT, part of this work has
been published in IEEE MASS 202
Advances in micro-structured optical fibres and their applications
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Greatwall and Polo-like Kinase 1 Coordinate to Promote Checkpoint Recovery
Checkpoint recovery upon completion of DNA repair allows the cell to return to normal cell cycle progression and is thus a crucial process that determines cell fate after DNA damage. We previously studied this process in Xenopus egg extracts and established Greatwall (Gwl) as an important regulator. Here we show that preactivated Gwl kinase can promote checkpoint recovery independently of cyclin-dependent kinase 1 (Cdk1) or Plx1 (Xenopus polo-like kinase 1), whereas depletion of Gwl from extracts exhibits no synergy with that of Plx1 in delaying checkpoint recovery, suggesting a distinct but related relationship between Gwl and Plx1. In further revealing their functional relationship, we found mutual dependence for activation of Gwl and Plx1 during checkpoint recovery, as well as their direct association. We characterized the protein association in detail and recapitulated it in vitro with purified proteins, which suggests direct interaction. Interestingly, Gwl interaction with Plx1 and its phosphorylation by Plx1 both increase at the stage of checkpoint recovery. More importantly, Plx1-mediated phosphorylation renders Gwl more efficient in promoting checkpoint recovery, suggesting a functional involvement of such regulation in the recovery process. Finally, we report an indirect regulatory mechanism involving Aurora A that may account for Gwl-dependent regulation of Plx1 during checkpoint recovery. Our results thus reveal novel mechanisms underlying the involvement of Gwl in checkpoint recovery, in particular, its functional relationship with Plx1, a well characterized regulator of checkpoint recovery. Coordinated interplays between Plx1 and Gwl are required for reactivation of these kinases from the G2/M DNA damage checkpoint and efficient checkpoint recovery
Synthesis and Cytotoxic Analysis of Some Disodium 3β,6β-Dihydroxysterol Disulfates
Disodium 3β,6β-dihydroxy-5α-cholestane disulfate (1) was synthesized in 4 steps with a high overall yield from cholesterol. First, cholesterol (4a) was converted to cholest-4-en-3,6-dione (5a) via oxidation with pyridinium chlorochromate (PCC) and then 5a was reduced by NaBH4 in the presence of NiCl2 to produce cholest-3β,6β-diol (6a). The reaction of 6a with the triethylamine-sulfur trioxide complex generated diammonium 3β,6β-dihydroxy-5α-cholestane disulfate (7a) and the treatment of 7a by cation exchange resin 732 (sodium form)(Na+) yielded the target steroid 1. Disodium 24-ethyl-3β,6β-dihydroxycholest-22-ene disulfate (2) and disodium 24-ethyl-3β,6β-dihydroxycholestane disulfate (3) were synthesized using a similar method. The cytotoxicity of these compounds against Sk-Hep-1 (human liver carcinoma cell line), H-292 (human lung carcinoma cell line), PC-3 (human prostate carcinoma cell line) and Hey-1B (human ovarian carcinoma cell line) cells was investigated. Our results indicate that presence of a cholesterol-type side chain at position 17 is necessary for their biological activity
- …