Showing papers by "Cochin University of Science and Technology published in 2016"

First measurement of electron neutrino appearance in NOvA

Abstract: We report results from the first search for ν_{μ}→ν_{e} transitions by the NOvA experiment. In an exposure equivalent to 2.74×10^{20} protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99±0.11(syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07±0.14(syst). The 3.3σ excess of events observed in the primary analysis disfavors 0.1π<δ_{CP}<0.5π in the inverted mass hierarchy at the 90% C.L.

First measurement of muon-neutrino disappearance in NOvA

Abstract: This paper reports the first measurement using the NOvA detectors of νμ disappearance in a νμ beam. The analysis uses a 14 kton-equivalent exposure of 2.74×1020 protons-on-target from the Fermilab NuMI beam. Assuming the normal neutrino mass hierarchy, we measure Δm232=(2.52+0.20−0.18)×10−3 eV2 and sin2θ23 in the range 0.38–0.65, both at the 68% confidence level, with two statistically degenerate best-fit points at sin2θ23=0.43 and 0.60. Results for the inverted mass hierarchy are also presented.

A review of national guidelines for management of COPD in Europe

Abstract: The quality of care can be improved by the development and implementation of evidence-based treatment guidelines. Different national guidelines for chronic obstructive pulmonary disease (COPD) exis ...

Assessment of climate variations in temperature and precipitation extreme events over Iran

Abstract: In this study, changes in the spatial and temporal patterns of climate extreme indices were analyzed. Daily maximum and minimum air temperature, precipitation, and their association with climate change were used as the basis for tracking changes at 50 meteorological stations in Iran over the period 1975–2010. Sixteen indices of extreme temperature and 11 indices of extreme precipitation, which have been quality controlled and tested for homogeneity and missing data, are examined. Temperature extremes show a warming trend, with a large proportion of stations having statistically significant trends for all temperature indices. Over the last 15 years (1995–2010), the annual frequency of warm days and nights has increased by 12 and 14 days/decade, respectively. The number of cold days and nights has decreased by 4 and 3 days/decade, respectively. The annual mean maximum and minimum temperatures averaged across Iran both increased by 0.031 and 0.059 °C/decade. The probability of cold nights has gradually decreased from more than 20 % in 1975–1986 to less than 15 % in 1999–2010, whereas the mean frequency of warm days has increased abruptly between the first 12-year period (1975–1986) and the recent 12-year period (1999–2010) from 18 to 40 %, respectively. There are no systematic regional trends over the study period in total precipitation or in the frequency and duration of extreme precipitation events. Statistically significant trends in extreme precipitation events are observed at less than 15 % of all weather stations, with no spatially coherent pattern of change, whereas statistically significant changes in extreme temperature events have occurred at more than 85 % of all weather stations, forming strongly coherent spatial patterns.

A Compact Quad Element Slotted Ground Wideband Antenna for MIMO Applications

Abstract: A compact planar quad element wideband antenna for multiple-input-multiple-output (MIMO) system is proposed in this communication. A single element consists of a partially grounded printed monopole antenna loaded with a split ring resonator. The bandwidth of the antenna is from 2.2 to 6.28 GHz (96.2%), which covers LTE (2.2–3.8 GHz), Bluetooth (2.4 GHz), WLAN (2.4 and 5.1–5.8 GHz), WiMAX (2.3–5.7 GHz), and ISM bands (2.4/5.2/5.8 GHz). The fabricated antenna has an isolation greater than 14 dB between its elements, with a peak gain of 4 dBi and a peak efficiency of 91%. Polarization diversity is employed to accommodate four elements in an FR4 substrate, with an overall dimension of $0.33\lambda \times 0.33\lambda \times 0.01\lambda $ . The antenna has a simple planar design which is easy to fabricate with no intricate process involved.

Enhanced Bee Colony Algorithm for Efficient Load Balancing and Scheduling in Cloud

Abstract: Cloud computing is a promising paradigm which provides resources to customers on their request with minimum cost. Cost effective scheduling and load balancing are major challenges in adopting cloud computation. Efficient load balancing methods avoids under loaded and heavy loaded conditions in datacenters. When some VMs are overloaded with several number of tasks, these tasks are migrated to the under loaded VMs of the same datacenter in order to maintain Quality of Service (QoS). This paper proposes a modification in the bee colony algorithm for efficient and effective load balancing in cloud environment. The honey bees foraging behaviour is used to balance load across virtual machines. The tasks removed from over loaded VMs are treated as honeybees and under loaded VMs are the food sources. The method also tries to minimize makespan as well as number of VM migrations. The experimental result shows that there is significant improvement in the QoS delivered to the customers.

Systemic antifungal therapy for proven or suspected invasive candidiasis: the AmarCAND 2 study

Abstract: In the context of recent guidelines on invasive candidiasis (IC), how French intensive care units (ICUs) are managing IC? This is a prospective observational multicenter cohort study. During 1 year (2012–2013), 87 French ICUs enrolled consecutive patients with suspected or proven IC (SIC or PIC) and receiving systemic antifungal therapy (SAT). Data were collected up to 28 days after inclusion. We studied 835 patients, 291 with PIC and 544 with SIC. At SAT initiation, patients with SIC were significantly more severe (SAPS II 50.1 ± 18.7 vs. 46.2 ± 18.0). Severe sepsis or septic shock prompted to initiate empiric SAT in 70 % of SIC. Within 4 days in median, the initial SAT was modified in 49 % of patients with PIC vs. 33 % patients with SIC. Modifications were most often motivated by mycological results, and de-escalation was the most frequent change. Regarding compliance to IC management guidelines, echinocandin was used for 182 (62.5 %) patients with PIC, and 287 (52.7 %) of those with SIC; central venous catheter was removed in 87 (54.3 %) of patients with candidaemia, and 43 of the remaining patients received echinocandin; and de-escalation was undertaken after 5 days of SAT in 142 patients, after 10 days in 13 patients. As 20.6 % of SIC were secondarily documented, 403/835 (48 %) patients had finally a proven IC. Candida albicans was the main pathogen (65.3 %), then Candida glabrata (15.9 %). The 28-day mortality rates were 40.0 % in candidaemia, 25.4 % in cIAI, and 26.7 % in deep-seated candidiasis. In the overall population of patients with proven IC, four independent prognostic factors were identified: immunosuppression (Odds Ratio (OR) = 1.977: 1.03–3.794 95 % confidence interval (CI), p = 0.04), age (OR = 1.035; 1.017–1.053 95 % CI; p 46 on ICU admission (OR = 2.894; 1.81–4.626 95 % CI; p < 0.001), and surgery just before or during ICU stay (OR = 0.473; 0.29–0.77 95 % CI; p < 0.001). When SAT is initiated in French ICUs, the IC is ultimately proven for 48 % of patients. Empiric SAT is initiated in severely ill ICU patients. The initial SAT is often adapted, with de-escalation to fluconazole when possible. Mortality rate remains high.

A Four-Port MIMO Antenna Using Concentric Square-Ring Patches Loaded With CSRR for High Isolation

Abstract: A novel four-port multiple-input-multiple-output (MIMO) antenna system is designed using concentric square-ring patch antennas. All four ports are made to resonate at 2.4 GHz ISM band with an overall system dimension of 60×60×1.6 mm 3 . This design uses complementary split-ring resonator (CSRR) loaded on its ground plane for enhanced isolation of - 22 dB between patch antenna elements. CSRR reduces mutual coupling by about 6.5 dB. The antenna operates with a 2:1 VSWR bandwidth of 75 MHz centered at 2.45 GHz. This collocated antenna system satisfies MIMO diversity performance with low envelope correlation between its waveforms. The effectiveness of concentric rings in MIMO design along with proposed isolation enhancement technique is validated using measurements from a prototype.

CAESAR: a new tool to assess relatives’ experience of dying and death in the ICU

Abstract: To develop an instrument designed specifically to assess the experience of relatives of patients who die in the intensive care unit (ICU). The instrument was developed using a mixed methodology and validated in a prospective multicentre study. Relatives of patients who died in 41 ICUs completed the questionnaire by telephone 21 days after the death, then completed the Hospital Anxiety and Depression Scale, Impact of Event Scale-Revised and Inventory of Complicated Grief after 3, 6, and 12 months. A total of 600 relatives were included, 475 in the main cohort and 125 in the reliability cohort. The 15-item questionnaire, named CAESAR, covered the patient’s preferences and values, interactions with/around the patient and family satisfaction. We defined three groups based on CAESAR score tertiles: lowest (≤59, n = 107, 25.9 %), middle (n = 185, 44.8 %) and highest (≥69, n = 121, 29.3 %). Factorial analysis showed a single dimension. Cronbach’s alpha in the main and reliability cohorts was 0.88 (0.85–0.90) and 0.85 (0.79–0.89), respectively. Compared to a high CAESAR score, a low CAESAR score was associated with greater risks of anxiety and depression at 3 months [1.29 (1.13–1.46), p = 0.001], post-traumatic stress-related symptoms at 3 [1.34 (1.17–1.53), p < 0.001], 6 [OR = 1.24 (1.06–1.44), p = 0.008] and 12 [OR = 1.26 (1.06–1.50), p = 0.01] months and complicated grief at 6 [OR = 1.40 (1.20–1.63), p < 0.001] and 12 months [OR = 1.27 (1.06–1.52), p = 0.01]. The CAESAR score 21 days after death in the ICU is strongly associated with post-ICU burden in the bereaved relatives. The CAESAR score should prove a useful primary endpoint in trials of interventions to improve relatives’ well-being.

High-Performance Flexible Solid-State Supercapacitor with an Extended Nanoregime Interface through in Situ Polymer Electrolyte Generation

Abstract: Here, we report an efficient strategy by which a significantly enhanced electrode–electrolyte interface in an electrode for supercapacitor application could be accomplished by allowing in situ polymer gel electrolyte generation inside the nanopores of the electrodes. This unique and highly efficient strategy could be conceived by judiciously maintaining ultraviolet-triggered polymerization of a monomer mixture in the presence of a high-surface-area porous carbon. The method is very simple and scalable, and a prototype, flexible solid-state supercapacitor could even be demonstrated in an encapsulation-free condition by using the commercial-grade electrodes (thickness = 150 μm, area = 12 cm2, and mass loading = 7.3 mg/cm2). This prototype device shows a capacitance of 130 F/g at a substantially reduced internal resistance of 0.5 Ω and a high capacitance retention of 84% after 32000 cycles. The present system is found to be clearly outperforming a similar system derived by using the conventional polymer elec...

Implementation of an inquisitive chatbot for database supported knowledge bases

Abstract: Chatbot is a piece of software that responds to natural language input and attempts to hold a conversation in a way that imitates a real person. Some chatbots are used for entertainment purposes, while others for business and commercial purposes. Chatbots are getting a lot of attention from business community right now as they can save costs in customer service centers and can handle multiple clients at a time. Successful implementation of a chatbot calls for correct analysis of user’s query by the bot and the formation of the correct response that should be given to the user. In many scenarios the information available from the user’s query is inadequate to provide the answer. In such contexts, the chatbot needs to be inquisitive so that it will be more interactive and can mimic a more natural human interaction. This paper reports the implementation of an inquisitive chatbot, which finds the missing data in query and probes the questions to users to collect data that are required to answer the query. Through this implementation, the level of interactivity between the user and the chatbot is improved.

Mechanical, thermal, and viscoelastic response of novel in situ CTBN/POSS/epoxy hybrid composite system

Abstract: The present study focuses on the preparation of a novel hybrid epoxy nanocomposite with glycidyl polyhedral oligomeric silsesquioxane (POSS) as nanofiller, carboxyl terminated poly(acrylonitrile-co-butadiene) (CTBN) as modifying agent and diglycidyl ether of bisphenol A (DGEBA) as matrix polymer. The reaction between DGEBA, CTBN, and glycidyl POSS was carefully monitored and interpreted by using Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). An exclusive mechanism of the reaction between the modifier, nanofiller, and the matrix is proposed herein, which attempts to explains the chemistry behind the formation of an intricate network between POSS, CTBN, and DGEBA. The mechanical properties, such as tensile strength, and fracture toughness, were also carefully examined. The fracture toughness increases for epoxy/CTBN, epoxy/POSS, and epoxy/CTBN/POSS hybrid systems with respect to neat epoxy, but for hybrid composites toughening capability of soft rubber particles is lost by the presence of POSS. Field emission scanning electron micrographs (FESEM) of fractured surfaces were examined to understand the toughening mechanism. The viscoelastic properties of epoxy/CTBN, epoxy/POSS, and epoxy/CTBN/POSS hybrid systems were analyzed using dynamic mechanical thermal analysis (DMTA). The storage modulus shows a complex behavior for the epoxy/POSS composites due to the existence of lower and higher crosslink density sites. However, the storage modulus of the epoxy phase decreases with the addition of soft CTBN phase. The Tg corresponding to epoxy-rich phase was evident from the dynamic mechanical spectrum. For hybrid systems, the Tg is intermediate between the epoxy/rubber and epoxy/POSS systems. Finally, TGA (thermo gravimetric analysis) studies were employed to evaluate the thermal stability of prepared blends and composites. POLYM. COMPOS., 2015. © 2015 Society of Plastics Engineers

Hexavalent chromium induces malignant transformation of human lung bronchial epithelial cells via ROS-dependent activation of miR-21-PDCD4 signaling.

Abstract: Hexavalent chromium [Cr(VI)] is a well-known human carcinogen associated with an increased risk of lung cancer. However, the mechanisms underlying Cr(VI)-induced carcinogenesis remain unclear. MicroRNA-21 (miR-21) is a key regulator of oncogenic processes. Studies have shown that miR-21 exerts its oncogenic activity by targeting the tumor suppressor gene programmed cell death 4 (PDCD4). The present study examined the role of miR-21-PDCD4 signaling in Cr(VI)-induced cell transformation and tumorigenesis. Results showed that Cr(VI) induces ROS generation in human bronchial epithelial (BEAS-2B) cells. Chronic exposure to Cr(VI) is able to cause malignant transformation in BEAS-2B cells. Cr(VI) caused a significant increase of miR-21 expression associated with an inhibition of PDCD4 expression. Notably, STAT3 transcriptional activation by IL-6 is crucial for the Cr(VI)-induced miR-21 elevation. Stable knockdown of miR-21 or overexpression of PDCD4 in BEAS-2B cells significantly reduced the Cr(VI)-induced cell transformation. Furthermore, the Cr(VI) induced inhibition of PDCD4 suppressed downstream E-cadherin protein expression, but promoted β-catenin/TCF-dependent transcription of uPAR and c-Myc. We also found an increased miR-21 level and decreased PDCD4 expression in xenograft tumors generated with chronic Cr(VI)-exposed BEAS-2B cells. In addition, stable knockdown of miR-21 and overexpression of PDCD4 reduced the tumorogenicity of chronic Cr(VI)-exposed BEAS-2B cells in nude mice. Taken together, these results demonstrate that the miR-21-PDCD4 signaling axis plays an important role in Cr(VI)-induced carcinogenesis.

Optoelectronic properties and Seebeck coefficient in SnSe thin films

Abstract: SnSe thin films of thickness 180 nm have been deposited on glass substrates by reactive evaporation at an optimized substrate temperature of 523 ± 5 K and pressure of 10−5 mbar. The as-prepared SnSe thin films are characterized for their structural, optical and electrical properties by various experimental techniques. The p-type conductivity, near-optimum direct band gap, high absorption coefficient and good photosensitivity of the SnSe thin film indicate its suitability for photovoltaic applications. The optical constants, loss factor, quality factor and optical conductivity of the films are evaluated. The results of Hall and thermoelectric power measurements are correlated to determine the density of states, Fermi energy and effective mass of carriers and are obtained as 2.8 × 1017 cm−3, 0.03 eV and 0.05m 0 respectively. The high Seebeck coefficient ≈ 7863 μV/K, reasonably good power factor ≈ 7.2 × 10−4 W/(mK2) and thermoelectric figure of merit ≈ 1.2 observed at 42 K suggests that, on further work, the prepared SnSe thin films can also be considered as a possible candidate for cryogenic thermoelectric applications.

Biochemical and stable carbon isotope records of mangrove derived organic matter in the sediment cores

Abstract: Core sediments from five mangrove ecosystems along northern Kerala Coast were collected to evaluate the nature and sources of organic matter in these ecosystems. General sedimentary parameters (pH, Eh, grain size and total organic carbon) and biochemical constituents (carbohydrate, lipid and protein) were analysed. The protein-to-carbohydrate ratio and lipid-to-carbohydrate ratio were calculated to assess the quality of organic matter in core sediments. Higher concentrations of biochemical components were recorded in surface sediments, with a dominance of carbohydrates followed by lipids and proteins. Protein/carbohydrate ratio was found to be <1 in the entire study region indicating a large content of aged and/or non-living organic matter in mangrove sediments. This also confirms the involvement of heterotrophic microorganisms in the organic carbon dynamics of the study area. The bulk elemental ratio (total organic carbon/total nitrogen) varied between 11.39 and 24.14 in the study region, recording minimum value at Kunjimangalam and maximum at Pappinissery. Samples from Kadalundi recorded low total organic carbon/total nitrogen ratio throughout the core, indicated a marine signature. Stable carbon isotopic ratio (−29.19 to −23.87 ‰) in the sediments suggested the dominance of terrestrially derived organic matter. Principal component analysis revealed that mangrove litter addition, diagenesis and accumulation of organic matter on fine grained sediments are the major processes controlling the distribution of the parameters in the study area.

A review on soil–structure interaction analysis of laterally loaded piles

Abstract: Soil–structure interaction plays an important role in the behavior of structure under static or dynamic loading. It influences the behavior of soil, as well as the response of pile under loading. The analysis is highly essential for predicting a more accurate structural behavior so as to improve the safety of structures under extreme loading conditions. The soil–pile system behavior is predominantly nonlinear and this makes the problem complicated. In a laterally loaded pile the load is resisted by the soil–pile interaction effect, which in turn depends on soil properties, pile material, pile diameter, loading type and bed slope of ground. The difficulty in the accountability of the influencing factors necessitates a careful study on soil–structure interaction problem. The analysis became easier with the debut of powerful computers and simulation tools such as finite element analysis software. A detailed literature review on soil–structure interaction analysis of laterally loaded piles is presented in this paper.

Fast UV sensing properties of n-ZnO nanorods/p-GaN heterojunction

Abstract: n-type ZnO nanorods are vertically grown over p-type Mg:GaN substrate by simple hydrothermal process to form a p-GaN/n-ZnO nanorods heterojunction. The heterojunction showed good rectifying behavior. The defect states in the heterojunction are analyzed in detail using photoluminescence studies. The device response is studied for various biasing conditions and UV light pulse illumination frequencies. The present device has the fastest UV response on comparison with devices based on solution grown ZnO nanorods. The device showed reproducible results even after long exposure to room temperature and humidity environment.

Phase space analysis of bulk viscous matter dominated universe

Abstract: We consider a Friedmann model of the universe with bulk viscous matter and radiation as the cosmic components. We study the asymptotic properties in the equivalent phase space by considering the three cases for the bulk viscous coefficient as (i) ζ = ζ 0, a constant (ii) $$ \zeta ={\zeta}_0+{\zeta}_1\frac{\overset{\cdot }{a}}{a} $$ , depending on velocity of the expansion of the universe and (iii) $$ \zeta ={\zeta}_0+{\zeta}_1\frac{\overset{\cdot }{a}}{a}+{\zeta}_2\frac{\overset{\cdot \cdot }{a}}{\overset{\cdot }{a}} $$ , depending both on velocity and acceleration of the expansion of the universe. It is found that all the three cases predicts the late acceleration of the universe. However, a conventional realistic behaviour of the universe, i.e., a universe having an initial radiation dominated phase, followed by decelerated matter dominated phase and then finally evolving to accelerated epoch, is shown only when ζ = ζ 0, a constant. For the other two cases, it does not show either a prior conventional radiation dominated phase or a matter dominated phase of the universe.

On a queueing-inventory with reservation, cancellation, common life time and retrial

Abstract: In this paper we model a queueing-inventory system that has applications in railway and airline reservation systems. Maximum items in the inventory is $$S$$ which have a random common life time; this includes those that are sold in particular cycle. A customer, on arrival to an idle server with at least one item in inventory, is immediately taken for service; or else he joins the buffer of maximum size $$S$$ depending on number of items in the inventory (the buffer capacity varies and is, at any time, equal to the number of items in the inventory). The arrival of customers constitutes a Poisson process, demanding exactly one item each from the inventory. If there is no item in the inventory, the arriving customer first queue up in a finite waiting space of capacity $$K$$ . When it overflows an arrival goes to an orbit of infinite capacity with probability $$p$$ or is lost forever with probability $$1-p$$ . From the orbit he retries for service according to an exponentially distributed inter-occurrence time. The service time follows an exponential distribution. Cancellation of sold items before its expiry is permitted. Inventory gets added through cancellation of purchased items, until the expiry time. Cancellation time is assumed to be negligible. We analyze this system. Several performance characteristics are computed; expected sojourn time of the system in a cycle with “no inventory” and also “maximum inventory” are computed. Some illustrative numerical examples are presented. An optimization problem is numerically analyzed.

Nanomolar Level Determination of Octyl Gallate in Fats and Oils

Abstract: Monitoring of synthetic phenolic antioxidants in food is very important due to their potential harmfulness to human beings. Octyl gallate (OG) is a commonly used phenolic antioxidant as a preservative in food stuff such as margarine, lard, sunflower oil etc. Herein, a glassy carbon electrode (GCE) chemically modified with gold nanoparticles (AuNPs) followed by self-assembled monolayer of dodecane thiol (DDT) was fabricated and employed for the determination of OG. An anodic peak corresponds to the oxidation of OG was observed at a potential of 0.22 V at DDT/AuNPs/GCE by square wave voltammetry. Based on this, a novel electrochemical sensor was developed for the determination of OG in oils and fats. Linear calibration graph was obtained within the range 1.2 to 0.2 μM. The detection limit was found to be 8.3 nM which is remarkably lower than those reported previously. The applicability of the method was demonstrated by analyzing OG in commercially available food samples such as margarine, butter and sunflower oil.