4,436 research outputs found
Optimal offline broadcast scheduling with an energy harvesting transmitter
We consider an energy harvesting transmitter broadcasting data to two receivers. Energy and data arrivals are assumed to occur at arbitrary but known instants. The goal is to minimize the total transmission time of the packets arriving within a certain time window, using the energy that becomes available during this time. An achievable rate region with structural properties satisfied by the two-user AWGN BC capacity region is assumed. Structural properties of power and rate allocation in an optimal policy are established, as well as the uniqueness of the optimal policy under the condition that all the data of the “weaker ” user are available at the beginning. An iterative algorithm, DuOpt, based on block coordinate descent that achieves the same structural properties as the optimal is described. Investigating the ways to have the optimal schedule of two consecutive epochs in terms of energy efficiency and minimum transmission duration, it has been shown that DuOpt achieves best performance under the same special condition of uniqueness. Index Terms Packet scheduling, energy harvesting, AWGN broadcast channel, energy-efficient scheduling
Inhibiting CDK4/6 in pancreatic ductal adenocarcinoma via microRNA-21
Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies, with a 5-year survival rate of 5–10 %. The high mortality rate is due to the asymptomatic progression of clinical features in metastatic stages of the disease, which renders standard therapeutic options futile. PDAC is characterised by alterations in several genes that drive carcinogenesis and limit therapeutic response. The two most common genetic aberrations in PDAC are the mutational activation of KRAS and loss of the tumour suppressor CDK inhibitor 2A (CDKN2A), which culminate the activation of the cyclin-dependent kinase 4 and 6 (CDK4/6), that promote G1 cell cycle progression. Therapeutic strategies focusing on the CDK4/6 inhibitors such as palbociclib (PD-0332991) may potentially improve outcomes in this malignancy. MicroRNAs (miRs/miRNAs) are small endogenous non-coding RNA molecules associated with cellular proliferation, invasion, apoptosis, and cell cycle. Primarily, miR-21 promotes cell proliferation and a higher proportion of PDAC cells in the S phase, while knockdown of miR-21 has been linked to cell cycle arrest at the G2/M phase and inhibition of cell proliferation. In this study, using a CRISPR/Cas9 loss-of-function screen, we individually silenced the expression of miR-21 in two PDAC cell lines and in combination with PD-0332991 treatment, we examined the synergetic mechanisms of CDK4/6 inhibitors and miR-21 knockouts (KOs) on cell survival and death. This combination reduced cell proliferation, cell viability, increased apoptosis and G1 arrest in vitro. We further analysed the mitochondrial respiration and glycolysis of PDAC cells; then assessed the protein content of these cells and revealed numerous Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with PD-0332991 treatment and miR-21 knocking out. Our results demonstrate that combined targeting of CDK4/6 and silencing of miR-21 represents a novel therapeutic strategy in PDAC
Insights into mantle-type volatiles contribution from dissolved gases in artesian waters of the Great Artesian Basin, Australia
The geochemical features of the volatiles dissolved in artesian thermal waters discharged over three basins (Millungera, Galilee and Cooper basin) of the Australian Great Artesian Basin (GAB) consistently indicate the presence of fluids from multiple gas sources located in the crust (e.g. sediments, oil reservoirs, granites) as well as minor but detectable contributions of mantle/magma-derived fluids. The gases extracted from 19 water samples and analyzed for their chemical and isotopic composition exhibit amounts of CO up to about 340mlSTP/L marked by a δC (Total Dissolved Carbon) ranging from -16.9 to +0.18‰ vs PDB, while CH concentrations vary from 4.4×10 to 4.9mlSTP/L. Helium contents were between 9 and >2800 times higher than equilibrium with Air Saturated Water (ASW), with a maximum value of 0.12mlSTP/L. Helium isotopic composition was in the 0.02-0.21 Ra range (Ra = air-normalized He/He ratio). The three investigated basins differ from each other in terms of both chemical composition and isotopic signatures of the dissolved gases whose origin is attributed to both mantle and crustal volatiles. Mantle He is present in the west-central and hottest part of the GAB despite no evidence of recent volcanism. We found that the partial pressure of helium, significantly higher in crustal fluids than in mantle-type volatiles, enhances the crustal He signature in the dissolved gases, thus masking the original mantle contribution. Neotectonic activity involving deep lithospheric structures and magma intrusions, highlighted by recent geophysical investigations, is considered to be the drivers of mantle/magmatic volatiles towards the surface. The results, although pertaining to artesian waters from a vast area of >542,000km, provide new constraints on volatile injection, and show that fluids' geochemistry can provide additional and independent information on the geo-tectonic settings of the Great Artesian Basin and its geothermal potential
First report of Barley Yellow Dwarf Viruses (BYDVs) on dicotyledonous weed hosts in Turkey
Yellow dwarf viruses (YDVs) are economically destructive viral diseases of cereal crops, which cause the reduction of harvested yield and quality of grains. Up to now the identification of such viruses was limited to monocotyledonous Poaceae weed hosts, and was not investigated in dicotyledons. In this study, using DAS-ELISA and RT-PCR methods, 6 dicotyledonous weed species, collected from Trakya, Turkey, were examined for the presence of the YDVs pathogens BYDV-PAV, BYDV-MAV, BYDV-RMV, BYDV-SGV and CYDV-RPV. The screening tests revealed certain samples of Geranium dissectum L. and Juncus compressus Jacq. were infected with BYDV-PAV, while other samples of the same species were positive for BYDV-MAV. Additionally, RT-PCR tests of both weed species revealed cases of mixed infection by BYDV-PAV and BYDV-MAV. Transmission experiments using the aphid species Rhopalosiphum padi L. showed that BYDV-PAV was transmitted persistently from Geranium dissectum to barley cv. Barbaros seedlings. To our knowledge, this is the first report of Geranium dissectum and Juncus compressus as possible plant hosts of BYDV-PAV and BYDV-MAV in Turkey
International Tourism: An Unrecognized Potential in Rural Tourism Development
This paper presents an overview of international tourism and its role in rural economic development. It briefly describes the current approaches to rural economic development followed by a brief look at international tourism 1n the United States, and the potential for tourism in rural areas is examined. An initial step in assessing the extent to which international tourists visit rural America is determining the factors which currently attract those visitors to rural areas. The purpose of this paper is to profile potential international travelers to rural areas
Issues in Rural Community Tourism Development
Policy makers are turning to tourism as a potential industry force that may bring both economic and demographic stability to American rural communities. The systematic planning and appropriate utilization of community related physical, economic, and socio-cultural attributes is the key to the establishment of sustainable tourism. This paper focuses on several issues that are increasingly recognized as critical factors in the community system. Both quality of life and sense of place are emphasized. The paper concludes with broadly defined guidelines for future planning toward sustainable development
The podiform chromitites in the Dagküplü and Kavak mines, Eskisehir ophiolite (NW-Turkey) : genetic implications of mineralogical and geochemical data
Mantle tectonites from Eskisehir (NW-Turkey) include high-Cr chromitites with limited variation of Cr#, ranging from 65 to 82. Mg# ratios are between 54 and 72 and chromite grains contain up to 3.71 wt% Fe2O3 and 0.30 wt% TiO2. PGE contents are variable and range from 109 to 533 pbb. Chondrite-normalized PGE patterns are flat from Os to Rh and negatively sloping from Rh to Pd. Total PGE contents and low Pd/Ir ratios (from 0.07 to 0.41) of chromitites are consistent with typical ophiolitic chromitites. Chromite grains contain a great number of solid inclusions. They comprise mainly of highly magnesian (Mg# 95-98) mafic silicates (olivine, amphibole and clinopyroxene) and base-metal sulfide inclusions of millerite (NiS), godlevskite (Ni7S6), bornite (C5FeS4) with minor Ni arsenides of maucherite (Ni11As8) and orcelite (Ni5-xAs2), and unnamed Cu2FeS3 phases. Heazlewoodite, awaruite, pyrite, and rare putoranite (Cu9Fe,Ni9S16) were also detected in the matrix of chromite as secondary minerals. Laurite [(Ru,Os)S2] was the only platinum-group minerals found as primary inclusions in chromite. They occur as euhedral to subhedral crystals trapped within chromite grains and are believed to have formed in the high temperature magmatic stage during chromite crystallization. Laurite has limited compositional variation, range between Ru0.94Os0.03Ir0.02S1.95 and Ru0.64Os0.21Ir0.10S1.85, and contain up to 1.96 at% Rh and 3.67 at% As. Close association of some laurite grains with amphibole and clinopyroxene indicates crystallization from alkali rich fluid bearing melt in the suprasubduction environment. The lack of any IPGE alloys, as well as the low Os-content of laurite, assumes that the melt from which chromite and laurite were crystallized had relatively high fS2 but never reached the fS2 to crystallize the erlichmanite. The presence of millerite, as primary inclusions in chromite, reflects the increasing fS2 during the chromite crystallization
A hybrid energy-efficient routing protocol for wireless sensor networks
The usage and deployment of Wireless Sensor Networks (WSN) is rapidly increasing in many different monitoring and control applications. In the majority of these applications, energy is a key factor in sensor networks since the sensor nodes are battery powered and hence have limited resources of energy. In this context, choosing a proper energy-efficient routing technique can increase the network life time. In this paper, a new Hybrid Energy-Efficient (HEE) routing protocol is proposed. HEE uses Direct Transmission (DT) and Minimum Energy Transmission (MTE) which are two of the simplest methods in terms of computational complexity. However the design of routing techniques is highly dependent on the application and the performance may vary based on environmental parameters. The novel proposed method is applicable for different networks regardless of the size and distances between the nodes and also with different parameters such as number of nodes and message length. Simulation results show how HEE performs more efficiently in terms of energy consumption when comparing to DT and MTE.- (undefined
Histopathologic and immunohistochemical investigations of dental abscess formed in maxillofacial area
Background: An abscess is a pocket of pus that forms around the root of an infected tooth. In this study, we aimed to investigate the extracellular matrix proteases ADAMTS1, ADAMTS4, osteonectin, and osteopontin expressions in abscess fluid cells in jaws after implantation and prosthesis operation. Materials and methods: In this clinical study, abscess fluids belonging to 17 patients who applied to the Department of Oral and Maxillofacial Surgery were examined histopathologically and immunohistochemically. In the histopathological examination of the abscess fluid, separation of chromatin bridges in the nuclei of neutrophil cells, pyknosis and apoptotic changes in the nucleus, degenerative change in the cytoplasm, and occasional vacuolar structures were observed. Results: The positive reaction of ADAMTS1 was observed in fibroblast cells, plasma cells, and macrophage cells. The positive reaction of ADAMTS4 was observed in fibroblast cells, osteoclast cells, and some apoptotic leukocyte cells. Osteopontin expression in osteoclastic cells and polymorphonuclear cells was defined as positive. Osteonectin expression was positive in polymorphonuclear leukocytes and hypertrophic fibroblast cells. Conclusions: ADAMTS1 and ADAMTS4 may induce bone destruction with its distinctive property in alveolar bone resorption, which promotes the activation of osteoclasts, which can accelerate the destruction of the extracellular matrix in the acute phase. Furthermore, osteoclastic activity increased with the increase of osteonectin and osteopontin protein expression due to inflammation in the abscess cases
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