2,109 research outputs found
HEER: Hybrid Energy Efficient Reactive Protocol for Wireless Sensor Networks
Wireless Sensor Networks (WSNs) consist of numerous sensors which send sensed
data to base station. Energy conservation is an important issue for sensor
nodes as they have limited power.Many routing protocols have been proposed
earlier for energy efficiency of both homogeneous and heterogeneous
environments. We can prolong our stability and network lifetime by reducing our
energy consumption. In this research paper, we propose a protocol designed for
the characteristics of a reactive homogeneous WSNs, HEER (Hybrid Energy
Efficient Reactive) protocol. In HEER, Cluster Head(CH) selection is based on
the ratio of residual energy of node and average energy of network. Moreover,
to conserve more energy, we introduce Hard Threshold (HT) and Soft Threshold
(ST). Finally, simulations show that our protocol has not only prolonged the
network lifetime but also significantly increased stability period.Comment: 2nd IEEE Saudi International Electronics, Communications and
Photonics Conference (SIECPC 13), 2013, Riyadh, Saudi Arabi
Approximating fixed points of nonexpansive type mappings
In a uniformly convex Banach space, the convergence of Ishikawa iterates to a unique fixed point is proved for nonexpansive type mappings under certain conditions
Future of radiation therapy for malignant melanoma in an era of newer, more effective biological agents
The incidence of melanoma is rising. The primary initial treatment for melanoma continues to be wide local excision of the primary tumor and affected lymph nodes. Exceptions to wide local excision include cases where surgical excision may be cosmetically disfiguring or associated with increased morbidity and mortality. The role of definitive or adjuvant radiotherapy has largely been relegated to palliative measures because melanoma has been viewed as a prototypical radiotherapy-resistant cancer. However, the emerging clinical and radiobiological data summarized here suggests that many types of effective radiation therapy, such as radiosurgery for melanoma brain metastases, plaque brachytherapy for uveal melanoma, intensity modulated radiotherapy for melanoma of the head and neck, and adjuvant radiotherapy for selected high-risk, node-positive patients can improve outcomes. Similarly, although certain chemotherapeutic agents and biologics have shown limited responses, long-term control for unresectable tumors or disseminated metastatic disease has been rather disappointing. Recently, several powerful new biologics and treatment combinations have yielded new hope for this patient group. The recent identification of several clinically linked melanoma gene mutations involved in mitogen-activated protein kinase (MAPK) pathway such as BRAF, NRAS, and cKIT has breathed new life into the drive to develop more effective therapies. Some of these new therapeutic approaches relate to DNA damage repair inhibitors, cellular immune system activation, and pharmacological cell cycle checkpoint manipulation. Others relate to the investigation of more effective targeting and dosing schedules for underutilized therapeutics, such as radiotherapy. This paper summarizes some of these new findings and attempts to give some context to the renaissance in melanoma therapeutics and the potential role for multimodality regimens, which include certain types of radiotherapy as aids to locoregional control in sensitive tissues
Recent advances on the role of long non-coding RNAs in Alzheimer’s disease
Dementia is a progressive cognitive impairment that affects the activities of daily living. Alzheimer’s disease (AD) is the most common form of the dementia worldwide accounting for 60–80% of all dementia cases. With an estimated cost exceeding $290 billion in the USA, understanding and development of future therapeutic strategies is vital. In this perspective, we will be examining the current thinking of AD research and therapeutic strategies, while proposing a possible new direction for diagnosis, understanding, and treatment targets. Non-coding RNA accounts for the largest population of the human transcriptome. Long noncoding RNA (lncRNA) is a recent molecule of interest in the biomedical research which is non protein coding and is of length greater than 200 nucleotides. LncRNAs have been shown to play diverse roles within the cells such as posttranscriptional and posttranslational regulation, chromatin modulation, and protein complex organization. Given the flexible and diverse role in disease pathophysiology, lncRNAs may serve as novel therapeutic targets for diagnosis and treatment. Evidently, recent studies showed that dysregulation of lncRNA influences the clinical course of tumorigenesis, neurological disorders, cardiovascular disease, diabetes, and acquired immunodeficiency syndrome (Kazimierczyk et al., 2020). This indicates that lncRNA can provide a unique avenue of research and possible therapeutic targets in AD
On optimum stratification
In this manuscript, we discuss the problem of determining the optimum stratification of a study (or main) variable based on the auxiliary variable that follows a uniform distribution. If the stratification of survey variable is made using the auxiliary variable it may lead to substantial gains in precision of the estimates. This problem is formulated as a Nonlinear Programming Problem (NLPP), which turn out to multistage decision problem and is solved using dynamic programming technique
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Absorbed Radiation Dose in Radiosensitive Organs Using 64- and 320-Row Multidetector Computed Tomography: A Comparative Study
Aim. To determine absorbed radiation dose (ARD) in radiosensitive organs during prospective and full phase dose modulation using ECG-gated MDCTA scanner under 64- and 320-row detector modes. Methods:. Female phantom was used to measure organ radiation dose. Five DP-3 radiation detectors were used to measure ARD to lungs, breast, and thyroid using the Aquilion ONE scanner in 64- and 320-row modes using both prospective and dose modulation in full phase acquisition. Five measurements were made using three tube voltages: 100, 120, and 135 kVp at 400 mA at heart rate (HR) of 60 and 75 bpm for each protocol. Mean acquisition was recorded in milligrays (mGy). Results:. Mean ARD was less for 320-row versus 64-row mode for each imaging protocol. Prospective EKG-gated imaging protocol resulted in a statistically lower ARD using 320-row versus 64-row modes for midbreast (6.728 versus 19.687 mGy, P < 0.001), lung (6.102 versus 21.841 mGy, P < 0.001), and thyroid gland (0.208 versus 0.913 mGy; P < 0.001). Retrospective imaging using 320- versus 64-row modes showed lower ARD for midbreast (10.839 versus 43.169 mGy, P < 0.001), lung (8.848 versus 47.877 mGy, P < 0.001), and thyroid gland (0.057 versus 2.091 mGy; P < 0.001). ARD reduction was observed at lower kVp and heart rate. Conclusions:. Dose reduction to radiosensitive organs is achieved using 320-row compared to 64-row modes for both prospective and retrospective gating, whereas 64-row mode is equivalent to the same model 64-row MDCT scanner
Active Clones: Source Code Clones at Runtime
Code cloning is a common programming practice, and there have been aconsiderable amount of research that investigated the implications of code clones onsoftware maintenance using static analysis. However, little has been done to investigatethe runtime implications of code cloning. In this paper we investigate sourcecode clones at runtime, referring to clones as ‘active clones’ if they are invokedwhen a software system is in use. For example, if a particular use u of a systemresults in a clone c being invoked, we say that clone c is active with respect to useu. From this definition and given a set of uses fu1;u2; :::g and clones fc1;c2; :::gwe are able to identify the extent clones are active at runtime and analyze activeclone resource use (e.g., CPU time) and define and calculate a set of active clonemetrics to provide insights into source code cloning implications at runtime. We developeda hybrid static and dynamic analysis technique for detecting and analysingactive clones, and conducted an empirical study on five software systems (HSQLDB,JHotDraw, RText, jEdit and UniCentaoPOS) to validate our approach. We found asmall portion of clones are active during a typical use of a software system, and thatactive clones have the potential for guiding a software developer’s code inspectionactivity during a software maintenance task
Influence of Natural Zeolite and Mineral additive on Bacterial Self-healing Concrete: A Review
With time, the development of micro-cracks in concrete is a frequently reported problem in the structures due to the ingress of harmful substances, leading to the degradation of its quality and strength, which ultimately declines the construction. The present work is a review paper based on enhancing the self-healing property of concrete by inducing different bacteria alone or incorporating different mineral additives. It has been seen that various rehabilitated methodologies are in queue to surmount concrete’s weaknesses and to increase its strength and durability. The latest methodology includes using non-pathogenic microbes in concrete as Microbial induced Calcium Carbonate Precipitation (MICCP). The property of precipitating calcium carbonate (CaCO3) crystals by their metabolic activities helps repair the cracks in harsh conditions and improve their strength. Ureolytic bacteria like Bacillus pasteurii/Sporosarcina pasteurii, Bacillus subtilis, Bacillus megaterium, etc., have a specific property by which they can excite urea when integrated with a calcium source and help in sealing the cracks by CaCO3 precipitation. Different studies have observed that specimens having a bacterial concentration of 105-107 cells/ml with Natural Zeolite (NZ) replacement (10%) represents better interaction of the microstructure of concrete because of the formation of calcium silicate hydrate (CSH) gel. Further, the reduction in CH bond with reduced pore space has also been observed. NZ alone enhances micro-structural property, but it shows CaCo3 precipitation and more densification of microstructure under bacterial combination. XRD also confirms an increase in the calcite composition when the bacterial concentration of 105-107 cells/ml is used. The overall properties of standard and high-strength bacterial concrete (105-107 cells/ml) with 10% Natural Zeolite replacement can provide a better option for the future of sustained and strong concrete. Doi: 10.28991/CEJ-2022-08-05-015 Full Text: PD
Optimum spacing between grooved tubes: an experimental study
An experimental study on the optimum spacing between grooved tubes is reported in this paper. Two grooved tubes having a pitch of 10 mm and 15 mm and a plain tube were considered for the heat transfer analysis. The spacing between two tubes with the same pitch was varied from 10 mm to 35 mm with a step size of 5 mm. The velocity of air flowing over the tube surfaces was changed from 0.4 m/s to 1 m/s using a blower fan. Based on Nusselt number
(Nu) the optimum spacing between the tubes was decided. The optimum spacing between grooved tubes of pitch 10 mm and 15 mm was compared with that of plain tubes. From the experimental analysis, it was noticed that with an increase in air velocity (increase in Reynolds number) the tube surface temperature reduced irrespective of any tube considered. Nu increased with an increase in air velocity for all the tubes. The important conclusion drawn from the
present study was that there exists a limiting spacing (optimum) between the tubes above which no change in Nu was observed. The spacing of 30 mm was found to be the optimum spacing between the tubes irrespective of its surface geometry modifications
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