596 research outputs found

    The application of isothermal microcalorimetry for studying mixed probiotic cultures

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    The main aim of this research was to explore the potential of the isothermal microcalorimeter to detect bacteria in mixed cultures; applied to investigate the antagonistic effect of commercial probiotics against pathogens and each other; and also the prebiotic potential of a substrate. Gastric tolerance of commercial probiotic products was also investigated with an improvement on current methods. An initial mixed culture study with Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli in the microcalorimeter showed that the microcalorimeter could detect their growth in mixed cultures; S. aureus was always outcompeted in growth. Antagonistic activity of probiotic strains, Lactobacillus acidophilus, Bifidobacterium lactis, Bifidobacterium bifidum or commercial probiotic products against P. aeruginosa, E. coli, S. aureus and the clinically important gut pathogen, Clostridium difficile was demonstrated in the microcalorimeter and was shown to be pH-dependent using neutralized and unmodified cell free culture supernatant (CFS) produced by the probiotic strains. But concentrated CFS of the probiotics also inhibited the pathogenic species in a non pH-dependent manner, likely due to specific antimicrobial substances or bacteriocins. The result also demonstrated that probiotic strains could compete with each other in growth when put together. The prebiotic potential of inulin was demonstrated with the microcalorimeter using faecal slurry and pure probiotic strains. Gastric tolerance assay of commercial probiotic products in porcine gastric fluid, SGF (acidified NaCl solution) and FaSSGF (acidified NaCl solution with biorelevant amounts of bile salt, pepsin and lecithin) mimicking the fed and fasted states showed significant differences between the products and fluids. In conclusion, the research showed that the microcalorimeter is a useful in vitro tool for detecting bacterial growth in mixed cultures and studying functional characteristics of probiotics and prebiotics; overcoming some of the limitations of the conventional methods

    An analytical channel model for emerging wireless networks-on-chip

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    Recently wireless Networks-on-Chip (WiNoCs) have been proposed to overcome the scalability and performance limitations of traditional multi-hop wired NoC architectures. However, the adaptation of wireless technology for on-chip communication is still in its infancy. Consequently, several challenges such as simulation and design tools that consider the technological constraints imposed by the wireless channel are yet to be addressed. To this end, in this paper, we propose and efficient channel model for WiNoCs which takes into account practical issues and constraints of the propagation medium, such as transmission frequency, operating temperature, ambient pressure and distance between the on-chip antennas. The proposed channel model demonstrates that total path loss of the wireless channel in WiNoCs suffers from not only dielectric propagation loss (DPL) but also molecular absorption attenuation (MAA) which reduces the reliability of the system

    Classification techniques for arrhythmia patterns using convolutional neural networks and Internet of Things (IoT) devices

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    The rise of Telemedicine has revolutionized how patients are being treated, leading to several advantages such as enhanced health analysis tools, accessible remote healthcare, basic diagnostic of health parameters, etc. The advent of the Internet of Things (IoT), Artificial Intelligence (AI) and their incorporation into Telemedicine extends the potential of health benefits of Telemedicine even further. Therefore, the synergy between AI, IoT, and Telemedicine creates diverse innovative scenarios for integrating cyber-physical systems into medical health to provide remote monitoring and interactive assistance to patients. Data from World Health Organization reports that 7.4 million people died because of Atrial Fibrillation (AF), recognizing the most common arrhythmia associated with human heart rate. Causes like unhealthy diet, smoking, poor resources to go to the doctor and based on research studies, about 12 and 17.9 million of people will be suffering the AF in the USA and Europe, in 2050 and 2060, respectively. The AF as a cardiovascular disease is becoming an important public health issue to tackle. By using a systematic approach, this paper reviews recent contributions related to the acquisition of heart beats, arrhythmia detection, IoT, and visualization. In particular, by analysing the most closely related papers on Convolutional Neural Network (CNN) and IoT devices in heart disease diagnostics, we present a summary of the main research gaps with suggested directions for future research

    Economic Dimensions of Tono and Vea Inland Fisheries of the Upper East Region of Ghana

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    This research sought to explore and understand the contribution of the fishery subsector of the Tono and Vea irrigation projects within the context of employment, income and revenue generations. The central argument of the study is that the continuous investment and appropriation of the fishery resources is being guided by an access regime in operation. Adopting a case study design, it triangulated both secondary and primary sources of data for effective analysis. Through random and systematic sampling, 192 fishermen and fishmongers were selected for the study. Structured and semi-structured interview techniques were used to solicit views from primary sources and complemented with relevant secondary documents from the organisations investigated (ICOUR and MoFA). Empirical results revealed that the access regime to the fishery was significantly open access and growth in the profit variable of the fishery was more induced by tonnes of fish catch than price. The fishery can play its proper role of improving upon direct and ancillary fishery income and employment when the ‘livelihood approach’ is used to value the river fisheries and the ecosystem for sustainable rural livelihoods.Keywords: Inland Fishery, Revenue, Employment, Income, Open Acces

    On the cooperative relaying strategies for multi-core wireless Network-on-Chip

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    Recently, hybrid wired-wireless Network-on-Chip (WiNoC) has been proposed as a suitable communication fabric to provide scalability and satisfy high performance demands of the exascale era of modern multi/many-core System-on-Chip (SoC) design. A well accepted low-latency wireless communication fabric for WiNoCs is millimeter wave (mm-Wave). However, the wireless channel of mm-Wave is lossy due to free space signal radiation with both dielectric propagation loss (DPL) and molecular absorption attenuation (MAA). This is exacerbated for edge situated cores and in macro-chips embodying thousands of cores. To this end, this paper proposes efficient relaying techniques to improve the signal strength of the wireless channel in the WiNoCs using on-chip networking approaches under the realistic SoC channel conditions. First, we propose a realistic relay communication channel for the WiNoCs to characterise both MAA and DPL which have drastic effect on the performance. We then derive and show that the channel capacity for a single-relay WiNoC employing Amplify-and-Forward (AF) and Decode-and-Forward (DF) relaying protocols increases by up to 20% and 25%, respectively, compared to the conventional direct transmission. The AF protocol outperforms the DF mode for shorter transmissions between the relay and the destination cores, while the reverse is observed in other conditions. A hybrid protocol is then proposed to exploit the performance advantages of both relaying protocols to address the unbalanced distance between the cores, providing the maximal channel capacity close to the cutset bound. Finally, our approach is further validated in multi-relay WiNoCs where the communications of the remote cores is assisted by multiple intermediate cores along with the details of associated realistic channel model in emerging many-core SoCs

    An improved wireless communication fabric for emerging Network-on-Chip design

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    Existing wireless communication interface has free space signal radiation which drastically reduces the received signal strength and hence reduces the throughput efficiency of Hybrid Wired-Wireless Network-on-Chip (WiNoC). This paper addresses the issue of throughput degradation by replacing the wireless layer of WiNoCs with a novel Complementary Metal Oxide Semiconductor (CMOS) based waveguide communication fabric that is able compete with the reliability of traditional wired NoCs. A combination of a novel transducer and a commercially available thin metal conductor coated with a low cost Taconic Taclamplus dielectric material is presented to generate surface wave signals with high signal integrity. Our experimental results demonstrate that, the proposed communication fabric can achieve a 5 dB operational bandwidth of about 60 GHz around the center frequency (60 GHz). Compared to existing WiNoCs, the proposed communication fabric a performance improvement of 13.8% and 10.7% in terms of throughput and average packet delay, respectively. Specifically, under realistic traffic patterns, the average packet latency can be reduced by 30% when the mm-Wave is replaced by the proposed communication fabric

    On the nanocommunications at THz band in graphene-enabled wireless network-on-chip

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    One of the main challenges towards the growing computation-intensive applications with scalable bandwidth requirement is the deployment of a dense number of on-chip cores within a chip package. To this end, this paper investigates the Wireless Network-on-Chip (WiNoC), which is enabled by graphene- based nanoantennas (GNAs) in Terahertz frequency band. We first develop a channel model between the GNAs taking into account the practical issues of the propagation medium, such as transmission frequency, operating temperature, ambient pressure and distance between the GNAs. In the Terahertz band, not only dielectric propagation loss (DPL) but also molecular absorption attenuation (MAA) caused by various molecules and their isotopologues within the chip package constitute the loss of signal transmission. We further propose an optimal power allocation to achieve the channel capacity subject to transmit power constraint. By analysing the effects of the MAA on the path loss and channel capacity, the proposed channel model shows that the MAA significantly degrades the performance at certain frequency ranges, e.g. 1.21 THz, 1.28 THz and 1.45 THz, of up to 31.8% compared to the conventional channel model, even when the GNAs are very closely located of only 0.01 mm. More specifically, at transmission frequency of 1 THz, the channel capacity of the proposed model is shown to be much lower than that of the conventional model over the whole range of temperature and ambient pressure of up to 26.8% and 25%, respectively. Finally, simulation results are provided to verify the analytical findings

    An efficient channel model for evaluating wireless NoC architectures

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    Wireless Networks-on-Chip (WiNoCs) have emerged to solve the scalability and performance bottleneck of conventional wired NoC architectures. However unlike communication in the macro-world, on-chip communication poses several constraints, hence there is the need for simulation and design tools that consider the effect of the wireless channel at the nanotechnology level. In this paper, we present a parameterizable channel model for WiNoCs which takes into account practical issues and constraints of the propagation medium, such as transmission frequency, operating temperature, ambient pressure and distance between the on-chip antennas. The proposed channel model demonstrates that total path loss of the wireless channel in WiNoCs suffers from not only dielectric propagation loss (DPL) but also molecular absorption attenuation (MAA) which reduces the reliability of the syste

    A resilient 2-D waveguide communication fabric for hybrid wired-wireless NoC design

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    Hybrid wired-wireless Network-on-Chip (WiNoC) has emerged as an alternative solution to the poor scalability and performance issues of conventional wireline NoC design for future System-on-Chip (SoC). Existing feasible wireless solution for WiNoCs in the form of millimeter wave (mm-Wave) relies on free space signal radiation which has high power dissipation with high degradation rate in the signal strength per transmission distance. Moreover, over the lossy wireless medium, combining wireless and wireline channels drastically reduces the total reliability of the communication fabric. Surface wave has been proposed as an alternative wireless technology for low power on-chip communication. With the right design considerations, the reliability and performance benefits of the surface wave channel could be extended. In this paper, we propose a surface wave communication fabric for emerging WiNoCs that is able to match the reliability of traditional wireline NoCs. First, we propose a realistic channel model which demonstrates that existing mm-Wave WiNoCs suffers from not only free-space spreading loss (FSSL) but also molecular absorption attenuation (MAA), especially at high frequency band, which reduces the reliability of the system. Consequently, we employ a carefully designed transducer and commercially available thin metal conductor coated with a low cost dielectric material to generate surface wave signals with improved transmission gain. Our experimental results demonstrate that the proposed communication fabric can achieve a 5dB operational bandwidth of about 60GHz around the center frequency (60GHz). By improving the transmission reliability of wireless layer, the proposed communication fabric can improve maximum sustainable load of NoCs by an average of 20:9% and 133:3% compared to existing WiNoCs and wireline NoCs, respectively

    In vitro inhibition of Clostridium difficile by commercial probiotics: A microcalorimetric study

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    The aim of the study was to investigate the influence of some commercial probiotics on the growth of Clostridium difficile using isothermal microcalorimetry, a technique which can monitor the real time growth of bacteria. Commercial probiotic strains and products, Lactobacillus acidophilus LA-5(®), Bifidobacterium lactis BB-12(®), Probio 7(®) and Symprove™ were co-cultured with C. difficile in Brain Heart Infusion (BHI) broth supplemented with 0.1% (w/v) l-cysteine hydrochloride and 0.1% (w/v) sodium taurocholate and monitored in the microcalorimeter. Pseudomonas aeruginosa NCIMB 8628 was also co-cultured with C. difficile and studied. The results indicated inhibition of C. difficile by the probiotics. The inhibition of C. difficile was shown to be pH-dependent using neutralized and unmodified cell free supernatant (CFS) produced by the probiotic strains. However, concentrated CFS of the probiotics also inhibited the intestinal pathogen in a non pH-dependent manner, likely due to specific antimicrobial substances produced. The results also indicated that C. difficile growth was greatly influenced by the presence of sodium taurocholate and by the pH of the medium. A medium pH of between 6.45 and 6.9 demonstrated maximum growth of the organism in the microcalorimeter
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