444 research outputs found

    Experimental field estimation of organic nitrogen formation in tree canopies

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    The content of organic N has been shown in many studies to increase during the passage of rain water through forest canopies. The source of this organic N is unknown, but generally assumed to come from canopy processing of wet or dry-deposited inorganic N. There have been very few experimental studies in the field to address the canopy formation or loss of organic N. We report two studies: a Scots pine canopy exposed to ammonia gas, and a Sitka spruce canopy exposed to ammonium and nitrate as wet deposition. In both cases, organic N deposition in throughfall was increased, but only represented a small fraction (<10%) of the additional inorganic N supplied, suggesting a limited capacity for net organic N production, similar in both conifer canopies under Scottish summertime conditions, of less than 1.6 mmol Nm2 mth1 (equivalent to 3 kg N ha1 y1)

    A Compact Antenna Design for Fifth Generation Wireless Communication System

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    This paper proposes a compact antenna design for wireless communication system that can operate at dual band frequencies which are 24.25 GHz and 38 GHz. The antenna with an overall size of 6.3 mm X 6.0 mm is printed on RogersRT5880 type of substrate with a thickness of 0.787 mm. The simulated reflection coefficient result is < -10 dB for both frequencies which makes it suitable for 5G applications. The proposed antenna has a stable gain value of 7.23 dBi at 24.25 GHz and 3.69 dBi at 38 GHz. All the simulation result was performed by using CST Microwave Studio Software. The result shows the feasibility of this antenna to be applied for future 5G application. © The Authors, published by EDP Sciences, 2017

    Let\u27s Talk About How We Talk: Communication Agreements in the Library Workplace

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    Purpose: This chapter introduces a new tool, termed the Communication Agreement, for enhancing communication in the library workplace. The chapter defines the communication agreement, provides discussion questions for forming a communication agreement, provides examples of how communication agreements are beneficial to a diverse library workforce, and provides strategies to informally assess communication agreements’ effectiveness. Practical implications: Communication problems in diverse library workplaces can lead to, or exacerbate, conflict between employees. Generational, cross-cultural, gender, and other differences can lead to misunderstandings and conflict between employees. The communication agreement provides library managers with a tool to bridge differences in communication styles between employees, enable employees to engage in more effective communication, assist employees in developing better understandings and respect for colleagues of different backgrounds, and raise employees’ emotional intelligences. Originality/Value: Numerous resources and publications provide generalized approaches to communicating with others in a heterogeneous workplace or team, but the communication agreement provides a new approach for developing effective communication between people in a diverse library workplace. Limitations: The chapter lays out informal assessment strategies for the communication agreement, but formal assessment methods and metrics still need to be developed

    A Method for Generation of Bone Marrow-Derived Macrophages from Cryopreserved Mouse Bone Marrow Cells

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    The broad use of transgenic and gene-targeted mice has established bone marrow-derived macrophages (BMDM) as important mammalian host cells for investigation of the macrophages biology. Over the last decade, extensive research has been done to determine how to freeze and store viable hematopoietic human cells; however, there is no information regarding generation of BMDM from frozen murine bone marrow (BM) cells. Here, we establish a highly efficient protocol to freeze murine BM cells and further generate BMDM. Cryopreserved murine BM cells maintain their potential for BMDM differentiation for more than 6 years. We compared BMDM obtained from fresh and frozen BM cells and found that both are similarly able to trigger the expression of CD80 and CD86 in response to LPS or infection with the intracellular bacteria Legionella pneumophila. Additionally, BMDM obtained from fresh or frozen BM cells equally restrict or support the intracellular multiplication of pathogens such as L. pneumophila and the protozoan parasite Leishmania (L.) amazonensis. Although further investigation are required to support the use of the method for generation of dendritic cells, preliminary experiments indicate that bone marrow-derived dendritic cells can also be generated from cryopreserved BM cells. Overall, the method described and validated herein represents a technical advance as it allows ready and easy generation of BMDM from a stock of frozen BM cells

    Remission of Behcet's disease with anti-tumor necrosis factor monoclonal antibody therapy: a case report

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    BACKGROUND: Behcet's disease (BD) is a chronic relapsing multisystem inflammatory disorder with mucocutaneous, ocular, articular, vascular, gastrointestinal and central nervous system manifestations. Tumor necrosis factor (TNF)-alpha is believed to play a pivotal role in BD. Therapeutic blockade of the activity of TNF has been successfully given in a short course of therapy with favorable effects in patients with BD refractory to conventional immunosuppressive drugs. We aimed to find out whether a 12-month treatment with infliximab, a chimeric monoclonal antibody to TNF-alpha, had any beneficial effect in reducing relapses of a patient with long-standing BD refractory to conventional immunosuppressive drugs. CASE PRESENTATION: A 54 year-old-woman with a 35-year history of BD with orogenital ulcerations, arthritis in the right knee and retinal lesions compatible with vasculitis received infliximab, 5 mg/kg by a two-hour intravenous infusion. Symptoms improved within 24 hours and eight days later the genital and oral ulcers healed as well as the arthritis in the right knee subsided. The retinal infiltrates completely resolved within 10 days. The infusions were repeated at weeks 2, 6, 14, 22 and then every 8 weeks. The patient was able to return to her domestic daily life. No exacerbation of the mucocutaneous ocular or arthritic symptoms occurred during the treatment period. CONCLUSIONS: Previous studies have suggested that infliximab given in a short course of treatment is effective in inducing remission of severe mucocutaneous, gastrointestinal and ocular manifestations of BD. Our patient received a 12-month infliximab treatment showing a favorable effect on remission of BD manifestations. The long-term infliximab treatment appears as a new therapeutic option for patients with active BD who failed to respond to conventional immunosuppressive agents

    Influences of mentoring functions on job satisfaction and organizational commitment of graduate employees

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    Abstract: A significant percentage of the workforce, within the construction sector is nearing retirement age over the next ten years. These employees have acquired a tremendous amount of knowledge about how things work, how to get things done and who to go to when problems arise. Losing their expertise and experience could significantly reduce efficiency, resulting in costly mistakes, unexpected quality problems, or significant disruptions in services and or performance. The business world has long known and relied upon mentoring as a proven technique for developing in house talent. Previous studies proved that the implementation of mentoring programme is beneficial for enhancing employee skills and attitudes. Few researchers are devoted to exploring the impact. This paper is aimed at examining the effects of mentoring functions on the job satisfaction and organizational commitment of new graduates in the South African construction industry..

    Exotendons for assistance of human locomotion

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    BACKGROUND: Powered robotic exoskeletons for assistance of human locomotion are currently under development for military and medical applications. The energy requirements for such devices are excessive, and this has become a major obstacle for practical applications. Legged locomotion in many animals, however, is very energy efficient. We propose that poly-articular elastic mechanisms are a major contributor to the economy of locomotion in such specialized animals. Consequently, it should be possible to design unpowered assistive devices that make effective use of similar mechanisms. METHODS: A passive assistive technology is presented, based on long elastic cords attached to an exoskeleton and guided by pulleys placed at the joints. A general optimization procedure is described for finding the best geometrical arrangement of such "exotendons" for assisting a specific movement. Optimality is defined either as minimal residual joint moment or as minimal residual joint power. Four specific exotendon systems with increasing complexity are considered. Representative human gait data were used to optimize each of these four systems to achieve maximal assistance for normal walking. RESULTS: The most complex exotendon system, with twelve pulleys per limb, was able to reduce the joint moments required for normal walking by 71% and joint power by 74%. A simpler system, with only three pulleys per limb, could reduce joint moments by 46% and joint power by 47%. CONCLUSION: It is concluded that unpowered passive elastic devices can substantially reduce the muscle forces and the metabolic energy needed for walking, without requiring a change in movement. When optimally designed, such devices may allow independent locomotion in patients with large deficits in muscle function

    Default-Mode-Like Network Activation in Awake Rodents

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    During wakefulness and in absence of performing tasks or sensory processing, the default-mode network (DMN), an intrinsic central nervous system (CNS) network, is in an active state. Non-human primate and human CNS imaging studies have identified the DMN in these two species. Clinical imaging studies have shown that the pattern of activity within the DMN is often modulated in various disease states (e.g., Alzheimer's, schizophrenia or chronic pain). However, whether the DMN exists in awake rodents has not been characterized. The current data provides evidence that awake rodents also possess ‘DMN-like’ functional connectivity, but only subsequent to habituation to what is initially a novel magnetic resonance imaging (MRI) environment as well as physical restraint. Specifically, the habituation process spanned across four separate scanning sessions (Day 2, 4, 6 and 8). At Day 8, significant (p<0.05) functional connectivity was observed amongst structures such as the anterior cingulate (seed region), retrosplenial, parietal, and hippocampal cortices. Prior to habituation (Day 2), functional connectivity was only detected (p<0.05) amongst CNS structures known to mediate anxiety (i.e., anterior cingulate (seed region), posterior hypothalamic area, amygdala and parabracial nucleus). In relating functional connectivity between cingulate-default-mode and cingulate-anxiety structures across Days 2-8, a significant inverse relationship (r = −0.65, p = 0.0004) was observed between these two functional interactions such that increased cingulate-DMN connectivity corresponded to decreased cingulate anxiety network connectivity. This investigation demonstrates that the cingulate is an important component of both the rodent DMN-like and anxiety networks
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