610 research outputs found
Enabling rapid and cost-effective creation of massive pervasive games in very unstable environments
Pervasive gaming is a new form of multimedia entertainment that extends the traditional computer gaming experience out into the real world. Through a combination of personal devices, positioning systems and other sensors, combined with wireless networking, a pervasive game can respond to player's movements and context and enable them to communicate with a game engine and other players. We review our recent deployment examples of pervasive games in order to explain their distinctive characteristics as wireless ad-hoc networking applications. We then identify the network support challenges of scaling pervasive games to include potentially mass numbers of players across extremely heterogeneous and unreliable networks. We propose a P2P overlay capable of storing large amount of game related data, which is the key to combating the loss of coverage and potential dishonesty of players. The proposed protocol decreases the deployment costs of the gaming infrastructure by self organization and utilizing storage space of users' devices. We demonstrate scalability and increased availability of data offered by the proposed protocol in simulation based evaluatio
Increasing communication reliability in manufacturing environments
This paper is concerned with low cost mechanisms that can increase reliability of machine to machine and machine to cloud communications in increasingly complex manufacturing environments that are prone to disconnections and faults. We propose a novel distributed and cooperative sensing framework that supports localized real time predictive analytics of connectivity patterns and detection of a range of faults together with issuing of notifications and responding on demand queries. We show that our Fault and Disconnection Aware Smart Sensing (FDASS) framework achieves significantly lower packet loss rates and communication delays in the face of unreliable nodes and networks when compared to the state of the art and benchmark approaches
Wireless mobile ad-hoc sensor networks for very large scale cattle monitoring
This paper investigates the use of wireless mobile ad hoc sensor networks in the nationwide cattle monitoring systems. This problem is essential for monitoring general animal health and detecting outbreaks of animal diseases that can be a serious threat for the national cattle industry and human health.
We begin by describing a number of related approaches for supporting animal monitoring applications and identify a comprehensive set of requirements that guides our approach. We then propose a novel infrastructure-less, self -organized peer to peer architecture that fulfills these requirements. The core of our work is the novel data storage and routing protocol for large scale, highly mobile ad hoc sensor networks that is based on the Distributed Hash Table (DHT) substrate that we optimize for disconnections. We show over a range of extensive simulations that by exploiting nodes’ mobility, packet overhearing and proactive caching we significantly improve availability of sensor data in these extreme conditions
Wireless mobile ad-hoc sensor networks for very large scale cattle monitoring
This paper investigates the use of wireless mobile ad hoc sensor networks in the nationwide cattle monitoring systems. This problem is essential for monitoring general animal health and detecting outbreaks of animal diseases that can be a serious threat for the national cattle industry and human health.
We begin by describing a number of related approaches for supporting animal monitoring applications and identify a comprehensive set of requirements that guides our approach. We then propose a novel infrastructure-less, self -organized peer to peer architecture that fulfills these requirements. The core of our work is the novel data storage and routing protocol for large scale, highly mobile ad hoc sensor networks that is based on the Distributed Hash Table (DHT) substrate that we optimize for disconnections. We show over a range of extensive simulations that by exploiting nodes’ mobility, packet overhearing and proactive caching we significantly improve availability of sensor data in these extreme conditions
Synthesis of new pyrimidine derivatives and their antiproliferative activity against selected human cancer cell lines
The toxicokinetic profile of Dex40-GTMAC3 : a novel polysaccharide candidate for reversal of unfractionated heparin
Though protamine sulfate is the only approved antidote of unfractionated heparin (UFH), yet may produce life threatening side effects such as systemic hypotension, catastrophic pulmonary vasoconstriction or allergic reactions. We have described 40 kDa dextrans (Dex40) substituted with glycidyltrimethylammonium chloride (GTMAC) as effective, immunogenically and hemodynamically neutral inhibitors of UFH. The aim of the present study was to evaluate in mice and rats toxicokinetic profile of the most promising polymer – Dex40-GTMAC3. Polymer was rapidly eliminated with a half-time of 12.5±3.0 min in Wistar rats, and was mainly distributed to the kidneys and liver in mice. The safety studies included the measurement of blood count and blood biochemistry, erythrocyte osmotic fragility and the evaluation of the histological alterations in kidneys, liver and lungs of mice and rats in acute and chronic experiments. We found that Dex40-GTMAC3 is not only effective but also very well tolerated. Additionally, we found that protamine may cause overt hemolysis with appearance of permanent changes in the liver and kidneys. In summary, fast renal clearance behavior and generally low tissue accumulation of Dex40-GTMAC3 is likely to contribute to its superior to protamine biocompatibility. Intravenous administration of therapeutic doses to living animals does not result in the immunogenic, hemodynamic, blood and organ toxicity. Dex40-GTMAC3 seems to be a promising effective and safe candidate for further clinical development as new UFH reversal agent
Phytosociology of snowbed and exposed ridge vegetation of Svalbard
Arctic vegetation still lacks a uniform system to classify its plant communities, the current arrangement of the phytosociological data being difficult to interpret. However, using modern methods, it has proved possible to organize the current data to create a suitable system based on numerical algorithms (detrended correspondence analysis and cluster analysis) and traditional methods for 135 phytosociological relevés from snowbed and exposed ridge habitats of Svalbard; 125 relevés were selected from twentieth and early twenty-first century publications, and ten relevés were collected by our group in 2012 from the Kaffiøyra Plain (Oscar II Land, NW Spitsbergen). Our analysis has shown there to be four associations and one community. Two associations and one community are distinguished within the Luzulion arcticae Gjærev. 1950: (1) the Pedicularietum hirsutae ass. nov., (2) the Deschampsietum alpinae (Nordh. 1943) Węgrzyn and Wietrzyk 2015 stat. nov., and (3) the Minuartia biflora community. Two syntaxa were assigned to the Luzulion arcuatae Elvebakk ex Węgrzyn and Wietrzyk 2015: (4) the Anthelietum juratzkanae Kobayashi ex Węgrzyn and Wietrzyk 2015 with a confirmed status and (5) the Gymnomitrietum coralloidis Hadač ex Węgrzyn and Wietrzyk 2015 stat. nov. was described by means of a new approach
Placenta-specific methylation of the vitamin D 24-hydroxylase gene: implications for feedback autoregulation of active vitamin D levels at the fetomaternal interface
Plasma concentrations of biologically active vitamin D (1,25-
(OH)2D) are tightly controlled via feedback regulation of renal
1-hydroxylase (CYP27B1; positive) and 24-hydroxylase
(CYP24A1; catabolic) enzymes. In pregnancy, this regulation is
uncoupled, and 1,25-(OH)2D levels are significantly elevated,
suggesting a role in pregnancy progression. Epigenetic regulation
of CYP27B1 and CYP24A1 has previously been described in
cell and animal models, and despite emerging evidence for a
critical role of epigenetics in placentation generally, little is
known about the regulation of enzymes modulating vitamin D
homeostasis at the fetomaternal interface. In this study, we
investigated the methylation status of genes regulating vitamin
D bioavailability and activity in the placenta. No methylation of
the VDR (vitamin D receptor) and CYP27B1 genes was found in
any placental tissues. In contrast, the CYP24A1 gene is methylated
in human placenta, purified cytotrophoblasts, and primary
and cultured chorionic villus sampling tissue. No methylation
was detected in any somatic human tissue tested. Methylation
was also evident in marmoset and mouse placental tissue. All
three genes were hypermethylated in choriocarcinoma cell
lines, highlighting the role of vitaminDderegulation in this cancer.
Gene expression analysis confirmed a reduced capacity for
CYP24A1 induction with promoter methylation in primary cells
and in vitro reporter analysis demonstrated that promoter
methylation directly down-regulates basal promoter activity
and abolishes vitamin D-mediated feedback activation. This
study strongly suggests that epigenetic decoupling of vitamin D
feedback catabolism plays an important role in maximizing
active vitamin D bioavailability at the fetomaternal interface
The first observation of Arctic char in glacial river of Austre Brøggerbreen (Ny-Ålesund, Svalbard, Norway)
Organic carbon accumulation in the glacier forelands with regard to variability of environmental conditions in different ecogenesis stages of High Arctic ecosystems
Recently deglaciated surfaces of glacier forelands are subjected to a variety of biotic and abiotic factors that lead to continuous soil formation. Until now, no attempt has been taken to analyse multiple factors that might affect soil development in the Arctic forelands. The main aim of this research was to determine the factors that influence soil development in the eight forelands of Svalbard. Moreover, the effects of both habitat type (glacier foreland and mature tundra) and geographical location on environmental variables treated as potential factors influencing soil formation were tested. In 2017, at each location a series of 1 plots was established; all 168 plots were investigated in terms of soil properties, spatial data, biological soil crusts (BSCs) properties, percent cover of BSCs and vascular plants. Stepwise multiple linear regression analysis using forward variable selection showed that soil development was significantly associated with six of fifteen analysed factors, i.e. BSC cover, carbon and nitrogen content in BSCs, soil pH, Topographic Wetness Index and foreland location. Two-way analysis of variance followed by Tukey’s test revealed significant differences in studied environmental variables between habitat types and studied locations, showing that foreland soils still retain particular initial characters to differentiate them from tundra soil
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