1,144 research outputs found
"WindFi" - a renewable powered base station for rural broadband
The HopScotch rural wireless broadband access test bed uses a network of low power base stations, powered by renewable energy sources to provide a low-cost rural broadband solution. In this paper we discuss the low power design aspects of the HopScotch base station and the impact on the required generation potential of renewable sources, battery bank sizing and the use of tracking PV arrays
Enabling rural broadband via TV "white space"
The use of multiple frequency bands within a wireless network allows the advantages of each band to be exploited. In this paper we discuss how HopScotch, a rural wireless broadband access test bed running in the Scottish Highlands and Islands, uses both 5 GHz and ultra high frequency "white space" bands to offer large data rates and expansive coverage whilst reducing the number of base stations or required transmission power. This reduction in energy consumption allows HopScotch to provide a low-cost and green solution for rural broadband delivery
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Tree of Life Synagogue Shooting in Pittsburgh: Preparedness, Prehospital Care, and Lessons Learned
On Saturday, October 27, 2018, a man with anti-Semitic motivations entered Tree of Life synagogue in the Squirrel Hill section of Pittsburgh, Pennsylvania; he had an AR-15 semi-automatic rifle and three handguns, opening fire upon worshippers. Eventually 11 civilians died at the scene and eight people sustained non-fatal injuries, including five police officers. Each person injured but alive at the scene received care at one of three local level-one trauma centers.Ā The injured had wounds often seen in war-settings, with the signature of high velocity weaponry.Ā We describe the scene response, specific elements of our hospital plans, the overall out-of-hospital preparedness in Pittsburgh, and the lessons learned
Expression of EpsteināBarr VirusāEncoded Small RNA (by the EBER-1 Gene) in Liver Specimens from Transplant Recipients with Post-Transplantation Lymphoproliferative Disease
Epstein-Barr virus (EBV)āassociated post-transplantation lymphoproliferative disease (PTLD) develops in 1 to 10 percent of transplant recipients, in whom it can be treated by a reduction in the level of immunosuppression. We postulated that the tissue expression of the small RNA transcribed by the EBER-1 gene during latent EBV infection would identify patients at risk for PTLD. We studied EBER-1 gene expression in liver specimens obtained from 24 patients 2 days to 22 months before the development of PTLD, using in situ hybridization with an oligonucleotide probe. Control specimens were obtained from 20 recipients of allografts with signs of injury due to organ retrieval, acute graft rejection, or viral hepatitis in whom PTLD had not developed 9 to 71 months after the biopsy. Of the 24 patients with PTLD, 17 (71 percent) had specimens in which 1 to 40 percent of mononuclear cells were positive for the EBER-1 gene. In addition, 10 of these 17 patients (59 percent) had specimens with histopathological changes suggestive of EBV hepatitis. In every case, EBER-1āpositive cells were found within the lymphoproliferative lesions identified at autopsy. Only 2 of the 20 controls (10 percent) had specimens with EBER-1āpositive cells (P<0.001), and such cells were rare. EBER-1 gene expression in liver tissue precedes the occurrence of clinical and histologic PTLD. The possibility of identifying patients at risk by the method we describe here and preventing the occurrence of PTLD by a timely reduction of immunosuppression needs to be addressed by future prospective studies. (N Engl J Med 1992;327:1710ā4.), POST-TRANSPLANTATION lymphoproliferative disease (PTLD), either polyclonal or monoclonal, complicates the clinical course of 1 to 10 percent of organ-transplant recipients.123 Immunohistochemical studies have demonstrated that the lymphoid cells within the lesions of PTLD almost invariably contain EpsteināBarr virus (EBV), primarily in a state of latent infection.4,5 The EBER-1 gene is expressed early during latent EBV infection and codes for a small messenger RNA (mRNA) expressed at up to 107 copies per cell.6 We and others have previously demonstrated the value of the detection of EBER-1 RNA for identifying EBV-infected cells in formalin-fixed paraffin-embedded tissues.7,8 In the current investigation, we usedā¦ Ā© 1992, Massachusetts Medical Society. All rights reserved
CD14 Counterregulates Lipopolysacharide- Induced Tumor Necrosis Factor-Ī± Production in a Macrophage Subset
In response to GM-CSF or M-CSF, macrophages (MĪ¦) can acquire
pro- or anti-inflammatory properties, respectively. Given
the importance of CD14 and Toll-like receptor (TLR) 4 in
lipopolysaccharide (LPS)-induced signaling, we studied the
effect of anti-CD14 antibody mediated CD14 blockade on
LPS-induced cytokine production, signal transduction and
on the expression levels of CD14 and TLR4 in GM-MĪ¦ and
M-MĪ¦. We found M-MĪ¦ to express higher levels of both surface
antigens and to produce more interferon (IFN)-Ī² and
interleukin-10, but less tumor necrosis factor (TNF)-Ī± than
GM-MĪ¦. Blockage of CD14 at high LPS concentrations increased
the production of proinflammatory cytokines and
decreased that of IFN-Ī² in M-MĪ¦ but not in GM-MĪ¦. We
show that phosphorylation states of signaling molecules of
the MyD88 (myeloid differentiation primary response 88),
TRIF (TIR-domain-containing adapter-inducing IFN-Ī²) and
MAPK (mitogen-activated protein kinase) pathways are not
altered in any way that would account for the cytokine overshoot
reaction. However, CD14 blockage in M-MĪ¦ decreased
TLR4 and CD14 expression levels, regardless of the presence
of LPS, indicating that the loss of the surface molecules prevented
LPS from initiating TRIF signaling. As TNF-Ī± synthesis
was even upregulated under these experimental conditions,
we suggest that TRIF is normally involved in restricting LPSinduced
TNF-Ī± overproduction. Thus, surface CD14 plays a
decisive role in the biological response by determining LPSinduced
signaling
Comparison of Three CD3-Specific Separation Methods Leading to Labeled and Label-Free T Cells
T cells are an essential part of the immune system. They determine the specificity of the immune response to foreign substances and, thus, help to protect the body from infections and cancer. Recently, T cells have gained much attention as promising tools in adoptive T cell transfer for cancer treatment. However, it is crucial not only for medical purposes but also for research to obtain T cells in large quantities, of high purity and functionality. To fulfill these criteria, efficient and robust isolation methods are needed. We used three different isolation methods to separate CD3-specific T cells from leukocyte concentrates (buffy coats) and Ficoll purified PBMCs. To catch the target cells, the Traceless Affinity Cell Selection (TACSĀ®) method, based on immune affinity chromatography, uses CD-specific low affinity Fab-fragments; while the classical Magnetic Activated Cell Sorting (MACSĀ®) method relies on magnetic beads coated with specific high affinity monoclonal antibodies. The REAleaseĀ® system also works with magnetic beads but, in contrast to MACSĀ®, low-affinity antibody fragments are used. The target cells separated by TACSĀ® and REAleaseĀ® are ālabel-freeā, while cells isolated by MACSĀ® still carry the cell specific label. The time required to isolate T cells from buffy coat by TACSĀ® and MACSĀ® amounted to 90 min and 50 min, respectively, while it took 150 min to isolate T cells from PBMCs by TACSĀ® and 110 min by REAleaseĀ®. All methods used are well suited to obtain T cells in large quantities of high viability (>92%) and purity (>98%). Only the median CD4:CD8 ratio of approximately 6.8 after REAleaseĀ® separation differed greatly from the physiological conditions. MACSĀ® separation was found to induce proliferation and cytokine secretion. However, independent of the isolation methods used, stimulation of T cells by anti CD3/CD28 resulted in similar rates of proliferation and cytokine production, verifying the functional activity of the isolated cells
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