103 research outputs found

    Study on Miniaturization of Antenna Using Metamaterials

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    Metamaterials (MTMs) are artificially built materials intended to give its properties from the internal structure, rather than the chemical composition found in natural materials. Electric permittivity (ε) and magnetic permeability (μ) are the two basic parameters which describe the electromagnetic property of a material or medium. Permittivity describes how a material is affected when it is placed in electric field. And permeability describes how a material is affected in presence of magnetic field. Metamaterials may have either negative permittivity or permeability or both may be negative simultaneously. The concept of metamaterials has additionally been utilized to design different kinds of patches with upgraded performance, such as improved gain and enhanced efficiency. Also, it has been utilized for the scaling down of patches. Two parameters are utilized in the collected works for antennas using metamaterials. We can adjust the refractive index of the metamaterial to positive, near-zero or negative values. Utilization of epsilon negative, MNG (μ - Mu negative) or DNG (double negative) are called metamaterial- based antennas and the use of metamaterial unit cell for example complementary split ring resonator, split ring resonator and so on are alluded as metamaterial inspired antennas. The design of complementary split ring resonator and its equivalent circuit will be discussed in this work. CSRR (complementary split ring resonator) provides both isolation enhancement and miniaturization for MIMO antenna

    A Case Study on 21 st Century Skills Development Through a Computer Based Maths Game

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    International audienceThe new technology developments that are emerging on the market demand re-skilling and updating competencies thus enabling people to adapt to new expectations in the 21st century workplace and life. Therefore, the education system should also prepare learners for lifelong learning through development of 21st century skills. Recent research on mathematics education also shows that for many students, math is not considered an easy subject and students are facing difficulties in developing logical thinking and problem solving skills. This paper introduces "Count With Me!", a novel educational computer based video game that teaches maths concepts. An investigation on how the game supports the development of learners' 21st century skills such as problem solving, self-directed learning, knowledge building and digital literacy is presented. The results of a case study in a 3rd level educational institution show that the large majority of students that took part in the case study acquired 21st century skills. 96.97% of students believed that the Count With Me! game helped them to develop their problem solving skills. 82.82% of students liked self-pacing themselves through the game based educational material. 78.78% of students agreed that the maths game has improved their knowledge and 81.81% of students were satisfied with their achievements in the game

    FINAL FRONTIER GAME: A CASE STUDY ON LEARNER EXPERIENCE

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    International audienceTeachers are facing many difficulties when trying to improve the motivation, engagement, and learning outcomes of students in Science, Technology, Engineering, and Mathematics (STEM) subjects. Game-based learning helps the students learn in an immersive and engaging environment, attracting them more towards STEM education. This paper introduces a new interactive educational 3D video game called Final Frontier, designed for primary school children. The proposed game design methodology is described and an analysis of a research study conducted in Ireland that investigated learner experience through a survey is presented. Results show that: (1) 92.5% of students have confirmed that the video game helped them to understand better the characteristics of the planets from the Solar system, and (2) 92.6% of students enjoyed the game and appreciated different game features, including the combination between fun and learning aspects which exists in the game

    The effect of adult Early Warning Systems education on nurses' knowledge, confidence and clinical performance: A systematic review

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    Aims: This review aims to determine the effect of adult Early Warning Systems education on nurses’ knowledge, confidence and clinical performance. Background: Early Warning Systems support timely identification of clinical deterioration and prevention of avoidable deaths. Several educational programmes have been designed to help nurses recognize and manage deteriorating patients. Little is known as to the effectiveness of these programmes. Design: Systematic review. Data sources: Academic Search Complete, CINAHL, MEDLINE, PsycINFO, PsycARTICLES, Psychology and Behavioral Science Collection, SocINDEX and the UK & Ireland Reference Centre, EMBASE, the Turning Research Into Practice database, the Cochrane Central Register of Controlled Trials (CENTRAL) and Grey Literature sources were searched between October and November 2015. Review methods: This is a quantitative systematic review using Cochrane methods. Studies published between January 2011 - November 2015 in English were sought. The risk of bias, level of evidence and the quality of evidence per outcome were assessed. Results: Eleven articles with 10 studies were included. Nine studies addressed clinical performance, four addressed knowledge and two addressed confidence. Knowledge, vital signs recording and Early Warning Score calculation were improved in the short term. Two interventions had no effect on nurses’ response to clinical deterioration and use of communication tools. Conclusion: This review highlights the importance of measuring outcomes using standardized tools and valid and reliable instruments. Using longitudinal designs, researchers are encouraged to investigate the effect of Early Warning Systems educational programmes. These can include interactive e-learning, on-site interdisciplinary Early Warning Scoring systems training sessions and simulated scenarios

    MXene-Embedded Porous Carbon-Based Cu<sub>2</sub>O Nanocomposites for Non-Enzymatic Glucose Sensors

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    This work explores the use of MXene-embedded porous carbon-based Cu2O nanocomposite (Cu2O/M/AC) as a sensing material for the electrochemical sensing of glucose. The composite was prepared using the coprecipitation method and further analyzed for its morphological and structural characteristics. The highly porous scaffold of activated (porous) carbon facilitated the incorporation of MXene and copper oxide inside the pores and also acted as a medium for charge transfer. In the Cu2O/ M/AC composite, MXene and Cu2O influence the sensingparameters, which were confirmed using electrochemical techniques such as cyclic voltammetry, electrochemical impedance spectroscopy, and amperometric analysis. The prepared composite shows two sets of linear ranges for glucose with a limit of detection (LOD) of 1.96 μM. The linear range was found to be 0.004 to 13.3 mM and 15.3 to 28.4 mM, with sensitivity values of 430.3 and 240.5 μA mM−1 cm−2, respectively. These materials suggest that the prepared Cu2O/M/AC nanocomposite can be utilized as a sensing material for non-enzymatic glucose sensors

    Fluorinated halon replacement agents in explosion inerting

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    The US Federal Aviation Administration (FAA) observed during explosion tests that at a low concentration of agent, some candidate halon replacement agents increased the explosion severity instead of mitigating the event. At UTC Aerospace Systems a test program was developed to assess the behaviour of alternative agents at values below inerting concentration. Two agents were selected, C2HF5 (Penta- fluoroethane, HFC-125) and C6F12O (FK-5-1-12, Novec™1230). Baseline tests were performed with unsuppressed C3H8 (propane)/air mixtures and C3H8/air mixtures with CF3Br (Halon 1301) and N2 (nitrogen). Using CF3Br or N2 at below inerting concentrations mitigated the explosion. C2HF5 was tested against C3H8 at stoichiometric (4 vol%) and lower explosion limit (LEL) (2 vol%). Against 4 vol% C3H8 the combustion was mitigated, proportional to agent concentration; however, low concentrations of C2HF5 with 2 vol% C3H8 enhanced the explosion. Tests with N2 against a volatile mixture of C3H8 with C2HF5 showed that N2 mitigated the events. Final tests were performed with low concentrations of C6F12O against C3H8/air mixtures. This showed similar behaviour to that observed with the C2HF5 tests. Normally during qualification tests for new agents the stoichiometric concentration of a fuel is deemed to be the worst case scenario and the baseline against which agents are tested. The above described test results show that this assumption may need to be reconsidered. This work shows that contrary to common assumption the agents investigated are unlikely to have acted chemically at the flame front, but most likely, mainly cooled the flame and changed the stoichiometry, i.e. the ratio of components of the flammable mixture

    Pathological and ecological host consequences of infection by an introduced fish parasite

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    The infection consequences of the introduced cestode fish parasite Bothriocephalus acheilognathi were studied in a cohort of wild, young-of-the-year common carp Cyprinus carpio that lacked co-evolution with the parasite. Within the cohort, parasite prevalence was 42% and parasite burdens were up to 12% body weight. Pathological changes within the intestinal tract of parasitized carp included distension of the gut wall, epithelial compression and degeneration, pressure necrosis and varied inflammatory changes. These were most pronounced in regions containing the largest proportion of mature proglottids. Although the body lengths of parasitized and non-parasitized fish were not significantly different, parasitized fish were of lower body condition and reduced weight compared to non-parasitized conspecifics. Stable isotope analysis (δ15N and δ13C) revealed trophic impacts associated with infection, particularly for δ15N where values for parasitized fish were significantly reduced as their parasite burden increased. In a controlled aquarium environment where the fish were fed ad libitum on an identical food source, there was no significant difference in values of δ15N and δ13C between parasitized and non-parasitized fish. The growth consequences remained, however, with parasitized fish growing significantly slower than non-parasitized fish, with their feeding rate (items s−1) also significantly lower. Thus, infection by an introduced parasite had multiple pathological, ecological and trophic impacts on a host with no experience of the parasite

    The cadherin–catenin complex in nasopharyngeal carcinoma

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    Abnormal Wnt signaling and impaired cell–cell adhesion due to abnormal E-cadherin and β-catenin function have been implicated in many cancers, but have not been fully explored in nasopharyngeal carcinoma. The aim of this study was to analyze β-Catenin cellular location and E-cadherin expression levels in nasopharyngeal carcinoma. E-cadherin expression levels were also correlated with clinical data and underlying pathology. β-Catenin and E-cadherin expression were examined in 18 nasopharyngeal carcinoma and 7 non-tumoral inflammatory pharynx tissues using immunohistochemical methods. Patient clinical data were collected, and histological evaluation was performed by hematoxylin/eosin staining. β-catenin was detected in membrane and cytoplasm in all cases of nasopharyngeal carcinoma, regardless of histological type; in non-tumoral tissues, however, β-catenin was observed only in the membrane. As for E-cadherin expression levels, strong staining was observed in most non-tumoral tissues, but staining was only moderate in nasopharyngeal carcinoma tissues. E-cadherin expression was associated with β-catenin localization, study group, metastatic disease, and patient outcomes. Reduced levels of E-cadherin protein observed in nasopharyngeal carinoma may play an important role in invasion and metastasis. Cytoplasmic β-catenin in nasopharyngeal carcinoma may impair cell–cell adhesion, promoting invasive behavior and a metastatic tumor phenotype

    Improved reference genome uncovers novel sex-linked regions in the Guppy (Poecilia reticulata)

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    This is the author accepted manuscript. The final version is available on open access from Oxford University Press via the DOI in this recordData availability: Population genomics data are available on ENA: Study: PRJEB10680 PCR-free data are available on ENA: Study PRJEB36450 Genome assembly is available on ENA ID: PRJEB36704; ERP119926 All scripts and pipelines are available on github: https://github.com/bfrasercommits/guppy_genomeTheory predicts that the sexes can achieve greater fitness if loci with sexually antagonistic polymorphisms become linked to the sex determining loci, and this can favour the spread of reduced recombination around sex determining regions. Given that sex-linked regions are frequently repetitive and highly heterozygous, few complete Y chromosome assemblies are available to test these ideas. The guppy system (Poecilia reticulata) has long been invoked as an example of sex chromosome formation resulting from sexual conflict. Early genetics studies revealed that male colour patterning genes are mostly but not entirely Y-linked, and that X-linkage may be most common in low predation populations. More recent population genomic studies of guppies have reached varying conclusions about the size and placement of the Y-linked region. However, this previous work used a reference genome assembled from short-read sequences from a female guppy. Here, we present a new guppy reference genome assembly from a male, using long-read PacBio single-molecule real-time sequencing (SMRT) and chromosome contact information. Our new assembly sequences across repeat- and GC-rich regions and thus closes gaps and corrects mis-assemblies found in the short-read female-derived guppy genome. Using this improved reference genome, we then employed broad population sampling to detect sex differences across the genome. We identified two small regions that showed consistent male-specific signals. Moreover, our results help reconcile the contradictory conclusions put forth by past population genomic studies of the guppy sex chromosome. Our results are consistent with a small Y-specific region and rare recombination in male guppies.Max Planck SocietyEuropean Research Council (ERC)Natural Environment Research Council (NERC

    Expert judgement reveals current and emerging UK climate-mortality burden

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    Weather and climate patterns play an intrinsic role in societal health, yet a comprehensive synthesis of specific hazard–mortality causes does not currently exist. Country-level health burdens are thus highly uncertain, but harnessing collective expert knowledge can reduce this uncertainty, and help assess diverse mortality causes beyond what is explicitly quantified. Here, surveying 30 experts, we provide the first structured expert judgement of how weather and climate directly impact mortality, using the UK as an example. Current weather-related mortality is dominated by short-term exposure to hot and cold temperatures leading to cardiovascular and respiratory failure. We find additional underappreciated health outcomes, especially related to long-exposure hazards, including heat-related renal disease, cold-related musculoskeletal health, and infectious diseases from compound hazards. We show potential future worsening of cause-specific mortality, including mental health from flooding or heat, and changes in infectious diseases. Ultimately, this work could serve to develop an expert-based understanding of the climate-related health burden in other countries
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