1,624 research outputs found
The freshwater pulseāa numerical model with application to the St. Lawrence Estuary
The freshwater pulse, characterized by a salinity minimum, has been observed in many coastal areas. A 2-D numerical model was developed to investigate the laterally averaged estuarine circulation, and the freshwater pulse in the St. Lawrence Estuary. The effects on the circulation and salinity of various parameters, including vertical eddy coefficients, river runoff, the bottom friction coefficient and the open boundary condition were studied.The freshwater pulse in the St. Lawrence Estuary was simulated using a seasonal variation of the freshwater runoff. In addition to simulating the downstream propagation and the reduction of the pulse\u27s amplitude toward both the ocean and the deep water in most of the areas, several interesting results were produced. These include (I) the finding of the maximum and minimum amplitudes of the pulse, (2) the increase of the amplitude from surface to deep water in the far upstream region, (3) the initial formation of the pulse at two surface locations, (4) the increase of the arrival time from surface to deep water, and (5) the increase of the arrival time for deep water pulses (at 25 m or deeper) toward the slope region where the upstream shallow water and the downstream deep water separates. The responses of the horizonal and vertical velocities to the freshwater pulse were described. Dynamics associated with the distribution, formation and propagation of the pulse were discussed
The Impact of Distance on the Accuracy of Luminance Measurement
AbstractMany researchers want to reduce the severe luminance difference caused by artificial lights or natural lighting and when luminance is highly uniform. This paper focused on the correlation between measured luminance and the distance of measurement from the light source. For this task, two types of luminance measuring methods were adopted. Namely, High Dynamic Range (HDR) image processing and CS-100 instrument for measuring surface luminance and point luminance respectively. The results indicate that there was a 3% decrease in measured luminance as the distance from the light source was increased by 1m
HnRNP Q Has a Suppressive Role in the Translation of Mouse Cryptochrome1
Precise regulation of gene expression is especially important for circadian timekeeping which is maintained by the proper oscillation of the mRNA and protein of clock genes and clock-controlled genes. As a main component of the core negative arm feedback loops in the circadian clock, the Cry1 gene contributes to the maintenance of behavioral and molecular rhythmicity. Despite the central role of Cry1, the molecular mechanisms regulating expression levels of Cry1 mRNA and protein are not well defined. In particular, the post-transcriptional regulation of Cry1 mRNA fate decisions is unclear. Here, we demonstrate that hnRNP Q binds to mCry1 mRNA via the 5'UTR. Furthermore, hnRNP Q inhibits the translation of mCry1 mRNA, leading to altered rhythmicity in the mCRY1 protein profile.1145Ysciescopu
Service Negotiation Model for Response Time in Distributed Networks
The important thing of QoS is that response time of service is transparently suggested to resource management system and network users. This helps to schedule jobs or guarantee the service level agreement. This paper proposes to specify a negotiation policy for response time of distributed network using network latency function. To monitor and manage service response time in distributed network, we identified the relationships between network/application performance and QoS parameters. We also provided the statistical analysis on mapping user level response time to application and network level parameters. To show the validation of the network latency function, we used the NS-2 network simulator and showed the efficiency of that function. Finally we suggested the negotiation of policy for response time of requested service
Mobile Learning Initiative through SMS: A Formative Evaluation
Mobile technologies such as mobile phones are becoming cheaper and easy to use. Almost all learners enrolled at the Open University Malaysia (OUM) own mobile phones. In a 2008 study to determine learnersā perceptions toward mobile learning, most (82.8 percent) indicated that they could imagine themselves learning through mobile devices. Hence, in mid-2009, a mobile learning initiative via text messaging was piloted for one of OUMās first semester courses entitled, āLearning Skills for Open and Distance Learning.ā The initiative was expected to provide learners with an enhanced learning environment that will, among others, spur them to perform various learning tasks in a timely manner, feel guided on what or how to learn as well as be reminded on certain aspects of the course. In addition, some of the messages sent were designed to motivate the learners. The main objective of the mobile learning initiative was to complement the print module and the two main modes of learning: face-to-face tutorials and online discussions. To determine learnersā response to the Short Message Service (SMS) messages, a formative evaluation through focus group discussions at six learning centres in the middle of the semester. Feedback and suggestions given were considered and adjustments were made in the implementation of the initiative for the second half of the semester. (Authors' abstract
A Bankruptcy Problem Approach to Load-shedding in Multiagent-based Microgrid Operation
A microgrid is composed of distributed power generation systems (DGs), distributed energy storage devices (DSs), and loads. To maintain a specific frequency in the islanded mode as an important requirement, the control of DGsā output and charge action of DSs are used in supply surplus conditions and load-shedding and discharge action of DSs are used in supply shortage conditions. Recently, multiagent systems for autonomous microgrid operation have been studied. Especially, load-shedding, which is intentional reduction of electricity use, is a critical problem in islanded microgrid operation based on the multiagent system. Therefore, effective schemes for load-shedding are required. Meanwhile, the bankruptcy problem deals with dividing short resources among multiple agents. In order to solve the bankruptcy problem, division rules, such as the constrained equal awards rule (CEA), the constrained equal losses rule (CEL), and the random arrival rule (RA), have been used. In this paper, we approach load-shedding as a bankruptcy problem. We compare load-shedding results by above-mentioned rules in islanded microgrid operation based on wireless sensor network (WSN) as the communication link for an agentās interactions
GM-CSF Promotes the Expansion and Differentiation of Cord Blood Myeloid-Derived Suppressor Cells, Which Attenuate Xenogeneic Graft-vs.-Host Disease
Myeloid-derived suppressor cells (MDSCs) are increased in tumor patients. Studies have shown generation of MDSCs from human peripheral blood mononuclear cells (PBMCs) by various cytokine combinations. However, large scale expansion of human MDSCs has not been demonstrated or applied in clinic settings. We investigated which cytokine combinations among GM-CSF/SCF, G-CSF/SCF, or M-CSF/SCF efficiently expand and differentiate human MDSCs following culture CD34+ cells of umbilical cord blood (CB). GM-CSF/SCF showed the greatest expansion of MDSCs. Up to 108 MDSCs (HLA-DRlowCD11b+CD33+) could be produced from 1 unit of CB following 6 weeks of continuous culture. MDSCs produced from culture of CD34+ cells with GM-CSF/SCF for 6 weeks had the greatest suppressive function of T cell proliferation and had the highest expression of immunosuppressive molecules including iNOS, arginase 1 and IDO compared to those differentiated with G-CSF/SCF or M-CSF/SCF. MDSCs secreted IL-10, TGB-Ī², and VEGF. The infusion of expanded MDSCs significantly prolonged the survival and decreased the GVHD score in a NSG xenogeneic model of GVHD. Injected MDSCs increased IL-10 and TGF-Ī² but decreased the level of TNF-Ī± and IL-6 in the serum of treated mice. Notably, FoxP3 expressing regulatory T (Treg) cells were increased while IFN-Ī³ (Th1) and IL-17 (Th17) producing T cells were decreased in the spleen of MDSC treated mice compared to untreated GVHD mice. Our results demonstrate that human MDSCs are generated from CB CD34+ cells using GM-CSF/SCF. These MDSCs exhibited potent immunosuppressive function, suggesting that they are useable as a treatment for inflammatory diseases such as GVHD
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