128 research outputs found
Selection of Combat Aircraft by Using Shannon Entropy and VIKOR Method
The selection of military defense equipment, especially fighter aircraft, has a bearing on the readiness ofthe Indian Air Force to defend the country’s independence. This study analyses a collection of alternative fighteraircraft that are linked to several choice factors using a multiple-criterion decision-making analysis technique. Tohandle such scenarios and make wise design judgements, a variety of criterion decision analysis techniques can beused. In this study, we assess fifth-generation fighter aircraft that incorporate significant 21st-century technologicaladvancements. These aircraft represent the state-of-the-art in fleet planning operations to 2022. These are generallyequipped with quick-moving airframes, highly integrated computer systems, superior avionics features, networkingwith other battlefield elements, situational awareness, command, control, and other communication capabilities.The study proposes a strategy for the selection of the fifth-generation combat aircraft for the National Air Force.Because of the problems, the Army needed an application that could assist with decision-making for combat selection systems. Solving the decision problem for evaluating fifteen military fighter alternatives in terms of nine decision criteria is the main objective of this work. We use the Shannon entropy and VIKOR model for the Air Force’s fleet program to evaluate military fighter aircraft suitability. The entropy technique is used to compute the weight of the criteria, and then the VIKOR technique has been used to rank the fighter aircraft
Naked strong curvature singularities in Szekeres space-times
We investigate the occurrence and nature of naked singularities in the
Szekeres space-times. These space-times represent irrotational dust. They do
not have any Killing vectors and they are generalisations of the
Tolman-Bondi-Lemaitre space-times. It is shown that in these space-times there
exist naked singularities that satisfy both the limiting focusing condition and
the strong limiting focusing condition. The implications of this result for the
cosmic censorship hypothesis are discussed.Comment: latex, 9 page
Role of Basti Karma towards the management of Madhumeha: an Ayurveda perspective
Ayurveda the Indian medical system mentioned Madhumeha as imbalance of the Doshas; Vata, Pitta and Kapha. Madhumeha correlated with diabetes as per modern medical science characterized by hyperglycemia and disturbance of water and electrolyte homeostasis. In Ayurveda (Brihatrayi) it is considered as Ashta mahagada as difficult to cure. It is also relates with life-style related metabolic disorder since consumption of junk foods, day time sleep, lack of exercises and sedentary habits may precipitate symptoms of diabetes. Now a day’s Madhumeha has become very common pathological condition affecting more than 20% of world population. Madhumeha may be managed by good conduction of Ahara-Vihara, Yoga, Sodhana karma and use of various ayurveda formulations, however recently Panchakarma has gain great attention towards the management of Madhumeha since some specific modalities of Panchakarma effectively removes vitiated Doshas and Vasti Karma is one of them. Considering this aspect present article summarized ayurveda perspective of Basti Karma towards the management of Madhumeha.
Keywords: Ayurveda, Diabetes, Madhumeha, Panchakarma, Basti Karma
Effect of zoledronic acid on functional outcome in cases of pertrochanteric femoral fractures in elderly patients operated with proximal femoral nailing
Background: Osteoporosis is a very common problem in geriatric population and postmenopausal women. Zoledronic acid injection is a very convenient and effective treatment option available for osteoporosis. Our study aimed to study the effect of zoledronic acid on functional outcome and fracture related complications in elderly patients with low energy pertrochanteric femoral fractures who were operated with proximal femoral nail.
Methods: This was a case control study. Elderly patients who underwent surgery in the form of proximal femoral nailing for low energy pertrochanteric femoral fractures were included. Injection zoledronic acid was given to every alternate patient who underwent surgery. Radiological healing was evaluated at six weekly intervals for six months and then 12 weekly intervals for one year. The Harris hip score was used to measure the functional outcome of the patient.
Results: Effective study population consisted of total 49 patients (25 cases and 24 controls). The mean union time in the cases and the control was 8.76±9.12 weeks and 7.04±1.57 weeks respectively. The mean Harris hip score was 86.742±7.55 in the cases and 84.339±11.20 in the control group. The p value was 0.3815. This study concluded that the two groups had no statistically significant difference between functional outcome and fracture related complications.
Conclusions: Zoledronic acid in patients admitted for surgery with osteoporotic fracture does not improve the functional outcome of the patients. It does not affect the mortality of the patients
Observation of multiple sausage oscillations in cool postflare loop
Using simultaneous high spatial (1.3 arc sec) and temporal (5 and 10 s)
resolution H-alpha observations from the 15 cm Solar Tower Telescope at ARIES,
we study the oscillations in the relative intensity to explore the possibility
of sausage oscillations in the chromospheric cool postflare loop. We use
standard wavelet tool, and find the oscillation period of ~ 587 s near the loop
apex, and ~ 349 s near the footpoint. We suggest that the oscillations
represent the fundamental and the first harmonics of fast sausage waves in the
cool postflare loop. Based on the period ratio P1/P2 ~ 1.68, we estimate the
density scale height in the loop as ~ 17 Mm. This value is much higher than the
equilibrium scale height corresponding to H-alpha temperature, which probably
indicates that the cool postflare loop is not in hydrostatic equilibrium.
Seismologically estimated Alfv\'en speed outside the loop is ~ 300-330 km/s.
The observation of multiple oscillations may play a crucial role in
understanding the dynamics of lower solar atmosphere, complementing such
oscillations already reported in the upper solar atmosphere (e.g., hot flaring
loops).Comment: 13 pages, 4 figures, accepted in MNRA
Outcomes of Unstable Subaxial Cervical Spine Fractures Managed by Posteroanterior Stabilization and Fusion
Study Design Retrospective study. Purpose To evaluate clinical and radiological outcomes of unstable subaxial cervical spine injuries managed by both posterior tension band column stabilization and anterior decompression, stabilization, and fusion. Overview of Literature Unstable subaxial cervical spine injuries often involve disruption of the anterior column and posterior tension band osteoligamentous complex. Such injuries need immediate surgical intervention. Different methods of reduction and surgical approaches have been published in the literature, with lack of consensus on a uniform or standardized method. Controversy still exists regarding stabilization of unstable cervical fractures by anterior or posterior approach alone or combined approaches. Methods We retrospectively evaluated 24 patients with post-traumatic unstable subaxial cervical spine injuries with their preoperative clinical details, X-ray, computed tomography, and magnetic resonance imaging of the cervical spine for fracture classification based on the mechanism of injury with status of disc herniation and posterior tension band disruption. All patients were managed by immediate reduction, posterior and anterior stabilization, and fusion in a single session of anesthesia. Data of all patients were analyzed with respect to pre- and postoperative neurological status based on American Spinal Injury Association grading, Visual Analog Scale score, the observation of bony fusion, and implant failure at 1, 3, 6, and 12 months. Data were analyzed using paired t-test. Results All patients had solid fusion at the desired level with considerable neurological improvement at the 1-year follow-up. Conclusions In unstable cervical injuries, stabilization of disrupted posterior tension band increases the stability of anterior plating and fusion. This method of immediate reduction and circumferential stabilization is rapid, safe, and effective and has a low rate of complications
Partitioning Apomixis Components to Understand and Utilize Gametophytic Apomixis
Apomixis is a method of reproduction to generate clonal seeds and offers tremendous potential to fix heterozygosity and hybrid vigor. The process of apomictic seed development is complex and comprises three distinct components, viz., apomeiosis (leading to formation of unreduced egg cell), parthenogenesis (development of embryo without fertilization) and functional endosperm development. Recently, in many crops, these three components are reported to be uncoupled leading to their partitioning. This review provides insight into the recent status of our understanding surrounding partitioning apomixis components in gametophytic apomictic plants and research avenues that it offers to help understand the biology of apomixis. Possible consequences leading to diversity in seed developmental pathways, resources to understand apomixis, inheritance and identification of candidate gene(s) for partitioned components, as well as contribution towards creation of variability are all discussed. The potential of Panicum maximum, an aposporous crop, is also discussed as a model crop to study partitioning principle and effects. Modifications in cytogenetic status, as well as endosperm imprinting effects arising due to partitioning effects, opens up new opportunities to understand and utilize apomixis components, especially towards synthesizing apomixis in crops
Cost-effectiveness of population-based screening for oral cancer in India: an economic modelling study
Background:
Oral cancer screening reduces mortality associated with oral cancer. The current study evaluated the cost-effectiveness of commonly used screening techniques, namely conventional oral examination (COE), toluidine blue staining (TBS), oral cytology (OC), and light-based detection (LBD) in the Indian scenario.
Methods:
The study used a Markov modelling approach to estimate the cost and health outcomes of four different approaches (COE, TBS, OC, and LBD) for screening oral cancer over time from a societal perspective. The discount rate was assumed as 3%. The outcomes estimated were oral cancer incident cases, deaths averted, and quality-adjusted life years (QALYs). To address the high burden of risk factors (tobacco and/or alcohol) in India, two Markov models were developed: Model A adopted a mass-screening strategy, whereas Model B adopted a high-risk screening strategy versus no screening. Probabilistic sensitivity analysis (PSA) was undertaken to address any parameter uncertainty.
Findings:
Mass-screening using LBD at three years had the least incident cases (3271.68) and averted the maximum number of oral cancer deaths (459.76). High-risk screening using COE at ten years interval incurred the least lifetime cost of 2,292,816.21 US/QALY), namely COE 5 years (−29.21), COE 10 years (−90.68), TBS 10 years (−60.54), and LBD 10 years (−13.51), were dominant over no-screening.
Interpretation:
The most cost-saving approach was the conventional oral examination at an interval of 10 years for oral screening in high-risk populations above 30 years of age.
Funding:
Department of Health Research, Ministry of Health & Family Welfare, Government of India
Advancements in cardiac structures segmentation: a comprehensive systematic review of deep learning in CT imaging
BackgroundSegmentation of cardiac structures is an important step in evaluation of the heart on imaging. There has been growing interest in how artificial intelligence (AI) methods—particularly deep learning (DL)—can be used to automate this process. Existing AI approaches to cardiac segmentation have mostly focused on cardiac MRI. This systematic review aimed to appraise the performance and quality of supervised DL tools for the segmentation of cardiac structures on CT.MethodsEmbase and Medline databases were searched to identify related studies from January 1, 2013 to December 4, 2023. Original research studies published in peer-reviewed journals after January 1, 2013 were eligible for inclusion if they presented supervised DL-based tools for the segmentation of cardiac structures and non-coronary great vessels on CT. The data extracted from eligible studies included information about cardiac structure(s) being segmented, study location, DL architectures and reported performance metrics such as the Dice similarity coefficient (DSC). The quality of the included studies was assessed using the Checklist for Artificial Intelligence in Medical Imaging (CLAIM).Results18 studies published after 2020 were included. The DSC scores median achieved for the most commonly segmented structures were left atrium (0.88, IQR 0.83–0.91), left ventricle (0.91, IQR 0.89–0.94), left ventricle myocardium (0.83, IQR 0.82–0.92), right atrium (0.88, IQR 0.83–0.90), right ventricle (0.91, IQR 0.85–0.92), and pulmonary artery (0.92, IQR 0.87–0.93). Compliance of studies with CLAIM was variable. In particular, only 58% of studies showed compliance with dataset description criteria and most of the studies did not test or validate their models on external data (81%).ConclusionSupervised DL has been applied to the segmentation of various cardiac structures on CT. Most showed similar performance as measured by DSC values. Existing studies have been limited by the size and nature of the training datasets, inconsistent descriptions of ground truth annotations and lack of testing in external data or clinical settings.Systematic Review Registration[www.crd.york.ac.uk/prospero/], PROSPERO [CRD42023431113]
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