34 research outputs found

    Adaptive channel estimation for LTE uplink

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    Third generation partnership project (3GPP) long term evolution (LTE) uses single carrier frequency division multiple access (SC-FDMA) in uplink transmission and orthogonal frequency division multiple access (OFDMA) scheme for the downlink. A variable step size based least mean squares (LMS) algorithm is formulated for a single carrier frequency division multiple access (SC-FDMA) system, in its channel estimation (CE). The weighting coefficients on the channel condition can be updated using this unbiased CE method. Channel and noise statistics information are not essential. Rather, it uses a phase weighting scheme to eliminate the signal fluctuations due to noise and decision errors. The convergence towards the true channel coefficient is guaranteed. The proposed algorithm is compared with the existing algorithms for BER and MSE performance in different channel environments

    Multiplicity of carbohydrate-binding sites in β-prism fold lectins: occurrence and possible evolutionary implications

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    The β-prism II fold lectins of known structure, all from monocots, invariably have three carbohydrate-binding sites in each subunit/domain. Until recently, β-prism I fold lectins of known structure were all from dicots and they exhibited one carbohydrate-binding site per subunit/domain. However, the recently determined structure of the β-prism fold I lectin from banana, a monocot, has two very similar carbohydrate-binding sites. This prompted a detailed analysis of all the sequences appropriate for two-lectin folds and which carry one or more relevant carbohydrate-binding motifs. The very recent observation of a β-prism I fold lectin, griffithsin, with three binding sites in each domain further confirmed the need for such an analysis. The analysis demonstrates substantial diversity in the number of binding sites unrelated to the taxonomical position of the plant source. However, the number of binding sites and the symmetry within the sequence exhibit reasonable correlation. The distribution of the two families of β-prism fold lectins among plants and the number of binding sites in them, appear to suggest that both of them arose through successive gene duplication, fusion and divergent evolution of the same primitive carbohydrate-binding motif involving a Greek key. Analysis with sequences in individual Greek keys as independent units lends further support to this conclusion. It would seem that the preponderance of three carbohydrate-binding sites per domain in monocot lectins, particularly those with the β-prism II fold, is related to the role of plant lectins in defence

    Rice area mapping in Palakkad district of Kerala using Sentinel-2 data and Geographic information system technique

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    Proper calculation of rice cultivation area well before harvest is critical for projecting rice yields and developing policies to assure food security. This research looks at how Remote Sensing (RS) and Geographic Information System (GIS) can be used to map rice fields in Palakkad district of Kerala. The area was delineated using three multi-temporal cloud free Sentinel-2 data with 10 m spatial resolution, matching to crop's reproductive stage during mundakan season (September-October to December-January), 2020-21. To make classification easier, the administrative boundary of district was placed over the mosaicked image. The rice acreage estimation and land use classification of the major rice tract of Palakkad district comprising five blocks was done using Iterative Self-Organisation Data Analysis Technique (ISODATA) unsupervised classification provision in ArcGIS 10.1 software, employing False Colour Composite (FCC) including Blue (B2), Green (B3), Red (B4) and Near-infrared (B8) Bands of Sentinel-2 images. The classification accuracy was determined by locating a total of 60 validation points throughout the district, comprising 30 rice and 30 non-rice points. The total estimated area was 24742.76 ha, with an average accuracy of 88.33% and kappa coefficient 0.766 in five blocks of Palakkad district. The information generated will be helpful in assessing the anticipated production as well as the water demand of the rice fields

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    SECURE CLOUD-BASED LOG MANAGEMENT SERVICE: A LITERATURE SURVEY II METHODS USED FOR LOGGING 2.1. The Syslog Protocol

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    ABSTRACT I INTRODUCTION Since the beginning, life has relied upon the transmission of messages. For the self-aware organic unit, these messages can relay many different things. The messages may signal danger, the presence of food or the other necessities of life, and many other things. In many cases, these messages are informative to other units and require no acknowledgement. As people interacted and created processes, this same principle was applied to societal communications. As an example, severe weather warnings may be delivered through any number of channels -a siren blowing, warnings delivered over television and radio stations, and even through the use of flags on ships. The expectation is that people hearing or seeing these warnings would realize their significance and take appropriate action. In most cases, no responding acknowledgement of receipt of the warning is required or even desired. Along these same lines, operating systems, processes and applications were written to send messages of their own status, or messages to indicate that certain events had occurred. These event messages generally had local significance to the machine operators. As the operating systems, processes and applications grew ever more complex, systems were devised to categorize and log these diverse messages and allow the operations staff to more quickly differentiates the notifications of problems from simple status messages. A log a record of events occurring within an organization's system or network According to these requirements, the desirable properties that we seek from a secure log management service In this paper we discuss some logging protocols and we will subsequently analyze each method against these properties. II METHODS USED FOR LOGGING The Syslog Protocol In many cases, a message is informative to other units and requires no acknowledgement. The syslog [3] process is a system that has been widely accepted in many operating systems for message logging. Flexibility was designed into this process so the operations staffs have the ability to configure the destination of messages sent from the processes running on the device. In one dimension, the events that were received by the syslog process could be logged to different files and also displayed on the console of the device. In another dimension, the syslog process could be configured to forward the messages across a network to the syslog process on another machine. The syslog process had to be built network-aware for some modicum of scalability since it was known that the operators of multiple systems would not have the time to access each system to review the message

    Non‑mimetic jumping spider responses towards three species of ants and their mimics

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    Ants and jumping spiders are prominent invertebrate predators in terrestrial ecosystems. Many jumping spiders are thought to avoid ants and their ant mimicking spiders, yet little is known if they discriminate among different species of ants or mimics. Chances of encountering multiple ants, and mimics all in a relatively short stretch of time and space is fairly common in the tropics, but how all these species interact with each other is not known. In a laboratory setup, we first examined the behavioral response of three ant species (Oecophylla smaragdina, the weaver ants; Camponotus sericeus, the golden backed carpenter ants, and Leptogenys processionalis, the procession ants), and their mimics in the genus Myrmarachne towards the non-mimetic jumping spider Plexippus paykulli. We then examined the response of P paykulli towards the three ant species, and their mimics. Our results suggest that weaver ants and procession ants are more aggressive towards non-mimetic jumping spiders as compared to golden backed ants. The three mimics also differed in their response towards the non-mimetic jumping spider: both weaver ant mimics and golden backed ant mimics charged at the non-mimetic jumping spiders as compared to the procession ant mimics. On the other hand, P. paykulli did not treat all ants similarly: while they looked, and approached the black procession ants by visual cues, they stayed away from weaver ants and golden backed ants. However, P. paykulli treated the three ant mimicking spiders similarly: while they looked at the mimics, they rarely approached or attacked them. Jumping spiders and ants are sympatric, and it may be advantageous to selectively avoid some ants over others. Studies, such as ours go a step closer in understanding multispecies predator–prey interactions

    Cloning, expression, purification, crystallization and preliminary X-ray studies of the mannose-binding lectin domain of MSMEG_3662 from Mycobacterium smegmatis

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    The mannose-binding lectin domain of MSMEG_3662 from Mycobacterium smegmatis has been cloned, expressed, purified and crystallized and the crystals have been characterized using X-ray diffraction. The Matthews coefficient suggests the possibility of two lectin domains in the triclinic cell. The amino-acid sequence of the domain indicates structural similarity to well characterized beta-prism II fold lectins

    Green synthesis of silver nanoparticles by Escherichia coli : Analysis of antibacterial activity

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    The emerging infectious diseases and the development of drug resistance in the pathogenic microorganism is a matter of serious concern. Despite the increased knowledge of microbial pathogenesis and application of modern therapeutics, the morbidity and mortality associated with the microbial infections still remains high. Therefore, there is a pressing demand to discover novel strategies and identify new antimicrobial agents to develop the next generation of drugs or agents to control microbial infections. The use of nanoparticles is gaining impetus in the present century as they possess defined chemical, optical and mechanical properties. In the present study green synthesis of silver nanoparticles by Escherichia coli has been done. Various parameters such as mixing ratio of culture supernatant and silver nitrate, media, temperature and pH for production of silver nanoparticles were optimised. The nanoparticles synthesised was characterized using SEM, FTIR and XRD. The antibacterial activity of silver nanoparticles synthesised using both pellet and supernatant against human pathogens Salmonella typhi, Vibrio cholerae, Bacillus subtilis and Klebsiella pneumoniae was analysed and MIC was calculated as 20µg and 50µg respectively
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