77 research outputs found
Separation Dynamics of Air-to-Air Missile and Validation with Flight Data
Prediction of flight characteristics of a store in the vicinity of an aircraft is vitally important for ensuring the safety of the aircraft and effectiveness of the store to meet the mission objective. Separation dynamics of an agile air-to-air-Missile from a fighter aircraft is numerically simulated using an integrated store separation dynamics suite. Chimera cloud of points along with a grid-free Euler solver is used to obtain aerodynamic force on the missile and the force is integrated using a rigid body dynamics code to obtain the missile position. In the present work, the suite is applied to a flight test case and sensitivity of trajectory variables on launch parameters is studied. Further, the results of the suite are compared with the flight data. The predicted body rates and Euler angles of missile compare well with the flight data.Â
Evaluation of results of anterior cruciate ligament reconstruction using peroneus longus graft
Background: The objective of the study was to assess clinical outcome and donor site morbidity of ACL reconstruction with peroneus longus tendon autografts in patients with ACL injury.Methods: 60 Patients who underwent ACL reconstruction using peroneus longus autograft after fulfilling inclusion criteria and obtaining informed consent were assessed preoperatively and postoperatively and followed up for 1 year. Graft diameter was measured intraoperatively. Functional score of knee (Tegner and Lysholm Knee score) and American Orthopedic Foot and Ankle Score (AOFAS) for donor site morbidity were recorded preoperatively and 1 year after surgery.Results: 93.3% Patients (56 out of 60) had good to excellent Lysholm knee score 1 year postoperatively and the mean AOFAS score was 96.7. The average peroneus longus graft diameter 8 .7mm.Conclusions: Anterior cruciate ligament reconstruction with peroneus longus autografts produces a good functional outcome at 1Â year follow-up, with the advantages of large graft diameter and excellent ankle function based on AOFAS score.res
Performance analysis of IMC based PID controller tuning on approximated process model
Classical Proportional Integral Derivative(PID) controller
remains the most popular approach for industrial process
control. Poor tuning of PID controller can lead to mechanical
wear associated with excessive control activity, poor control
performance and even poor quality products. In this paper, we
design procedure for the internal model control(IMC) approach
for tuning of conventional PID controller with proper tuning
rules. Furthermore, with help of analytical rule of step test
obtaining the effective first order time delay model of the process.
A simulation example of continuous stirred tank reactor is used
in which the IMC based PID tuning method implemented and
the step response of the closed loop system is compared with
classical tuning methods like Ziegler-Nichols and Cohen-Coon
HIV-1 gp120 Induces Expression of IL-6 through a Nuclear Factor-Kappa B-Dependent Mechanism: Suppression by gp120 Specific Small Interfering RNA
In addition to its role in virus entry, HIV-1 gp120 has also been implicated in HIV-associated neurocognitive disorders. However, the mechanism(s) responsible for gp120-mediated neuroinflammation remain undefined. In view of increased levels of IL-6 in HIV-positive individuals with neurological manifestations, we sought to address whether gp120 is involved in IL-6 over-expression in astrocytes. Transfection of a human astrocyte cell line with a plasmid encoding gp120 resulted in increased expression of IL-6 at the levels of mRNA and protein by 51.3±2.1 and 11.6±2.2 fold respectively; this effect of gp120 on IL-6 expression was also demonstrated using primary human fetal astrocytes. A similar effect on IL-6 expression was observed when primary astrocytes were treated with gp120 protein derived from different strains of X4 and R5 tropic HIV-1. The induction of IL-6 could be abrogated by use of gp120-specific siRNA. Furthermore, this study showed that the NF-ÎșB pathway is involved in gp120-mediated IL-6 over-expression, as IKK-2 and IKKÎČ inhibitors inhibited IL-6 expression by 56.5% and 60.8%, respectively. These results were also confirmed through the use of NF-ÎșB specific siRNA. We also showed that gp120 could increase the phosphorylation of IÎșBα. Furthermore, gp120 transfection in the SVGA cells increased translocation of NF-ÎșB from cytoplasm to nucleus. These results demonstrate that HIV-1 gp120-mediated over-expression of IL-6 in astrocytes is one mechanism responsible for neuroinflammation in HIV-infected individuals and this is mediated by the NF-ÎșB pathway
Human immunodeficiency virus type 1 viral protein R (Vpr) induces CCL5 expression in astrocytes via PI3K and MAPK signaling pathways
The IDENTIFY study: the investigation and detection of urological neoplasia in patients referred with suspected urinary tract cancer - a multicentre observational study
Objective
To evaluate the contemporary prevalence of urinary tract cancer (bladder cancer, upper tract urothelial cancer [UTUC] and renal cancer) in patients referred to secondary care with haematuria, adjusted for established patient risk markers and geographical variation.
Patients and Methods
This was an international multicentre prospective observational study. We included patients aged â„16 years, referred to secondary care with suspected urinary tract cancer. Patients with a known or previous urological malignancy were excluded. We estimated the prevalence of bladder cancer, UTUC, renal cancer and prostate cancer; stratified by age, type of haematuria, sex, and smoking. We used a multivariable mixed-effects logistic regression to adjust cancer prevalence for age, type of haematuria, sex, smoking, hospitals, and countries.
Results
Of the 11 059 patients assessed for eligibility, 10 896 were included from 110 hospitals across 26 countries. The overall adjusted cancer prevalence (n = 2257) was 28.2% (95% confidence interval [CI] 22.3â34.1), bladder cancer (n = 1951) 24.7% (95% CI 19.1â30.2), UTUC (n = 128) 1.14% (95% CI 0.77â1.52), renal cancer (n = 107) 1.05% (95% CI 0.80â1.29), and prostate cancer (n = 124) 1.75% (95% CI 1.32â2.18). The odds ratios for patient risk markers in the model for all cancers were: age 1.04 (95% CI 1.03â1.05; P < 0.001), visible haematuria 3.47 (95% CI 2.90â4.15; P < 0.001), male sex 1.30 (95% CI 1.14â1.50; P < 0.001), and smoking 2.70 (95% CI 2.30â3.18; P < 0.001).
Conclusions
A better understanding of cancer prevalence across an international population is required to inform clinical guidelines. We are the first to report urinary tract cancer prevalence across an international population in patients referred to secondary care, adjusted for patient risk markers and geographical variation. Bladder cancer was the most prevalent disease. Visible haematuria was the strongest predictor for urinary tract cancer
Deep PackGen: A Deep Reinforcement Learning Framework for Adversarial Network Packet Generation
Recent advancements in artificial intelligence (AI) and machine learning (ML)
algorithms, coupled with the availability of faster computing infrastructure,
have enhanced the security posture of cybersecurity operations centers
(defenders) through the development of ML-aided network intrusion detection
systems (NIDS). Concurrently, the abilities of adversaries to evade security
have also increased with the support of AI/ML models. Therefore, defenders need
to proactively prepare for evasion attacks that exploit the detection
mechanisms of NIDS. Recent studies have found that the perturbation of
flow-based and packet-based features can deceive ML models, but these
approaches have limitations. Perturbations made to the flow-based features are
difficult to reverse-engineer, while samples generated with perturbations to
the packet-based features are not playable.
Our methodological framework, Deep PackGen, employs deep reinforcement
learning to generate adversarial packets and aims to overcome the limitations
of approaches in the literature. By taking raw malicious network packets as
inputs and systematically making perturbations on them, Deep PackGen
camouflages them as benign packets while still maintaining their functionality.
In our experiments, using publicly available data, Deep PackGen achieved an
average adversarial success rate of 66.4\% against various ML models and across
different attack types. Our investigation also revealed that more than 45\% of
the successful adversarial samples were out-of-distribution packets that evaded
the decision boundaries of the classifiers. The knowledge gained from our study
on the adversary's ability to make specific evasive perturbations to different
types of malicious packets can help defenders enhance the robustness of their
NIDS against evolving adversarial attacks
Ethnomedicinal and pharmacological potential of marine macroalgae for CNS disorders: An overview
Marine macroalgae or seaweeds have created a favourable implication in the area of biomedical sciences, due to the present of potential bioactive substances. Extensive studies are reported on neuropharmacological effects of terrestrial plants and their constituents but there is inadequate information on the potential application of marine macroalgae for behavioural and neurological disorders. This review will emphasize on recent studies and/or updates on bioactive compounds or extracts from marine macroalgae and their potential toward CNS disorders
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