Observation of chaotic beats in a driven memristive Chua's circuit

In this paper, a time varying resistive circuit realising the action of an active three segment piecewise linear flux controlled memristor is proposed. Using this as the nonlinearity, a driven Chua's circuit is implemented. The phenomenon of chaotic beats in this circuit is observed for a suitable choice of parameters. The memristor acts as a chaotically time varying resistor (CTVR), switching between a less conductive OFF state and a more conductive ON state. This chaotic switching is governed by the dynamics of the driven Chua's circuit of which the memristor is an integral part. The occurrence of beats is essentially due to the interaction of the memristor aided self oscillations of the circuit and the external driving sinusoidal forcing. Upon slight tuning/detuning of the frequencies of the memristor switching and that of the external force, constructive and destructive interferences occur leading to revivals and collapses in amplitudes of the circuit variables, which we refer as chaotic beats. Numerical simulations and Multisim modelling as well as statistical analyses have been carried out to observe as well as to understand and verify the mechanism leading to chaotic beats.Comment: 30 pages, 16 figures; Submitted to IJB

School-based Yoga Intervention Programs Promoting Self-regulation And Adaptive Functioning Outcomes.pdf

Self-regulation deficits in childhood are related to difficulty focusing, aggressive behavior, and poor communication and coping skills. In contrast, strong self-regulation skills are associated with better adaptive functioning outcomes including stronger academic performance, social competence, and stress management, which may act as a protective factor for adverse outcomes in adulthood. A promising intervention to address self-regulatory deficits is school-based mindfulness and yoga programs. Mindful yoga practice can promote the ability to focus better, avoid fights, and calm down. With use of archival data, the present study aimed to analyze changes in student’s self-regulation and adaptive functioning outcomes post school-based yoga intervention. Adaptive functioning outcomes were measured by student reported benefits in the abilities to focus or pay attention better, avoid fights, and calm down when upset. The study explored whether student use of yoga at home influenced self-regulation changes. Results did not support positive changes overall in self-regulation after a school based yoga program or the influence of self-regulation change scores on adaptive functioning outcomes. Our study did support the influence of yoga at home and higher changes in self-regulation and self-reported benefits to adaptive functioning outcomes. Younger children were more likely to report greater benefits in adaptive functioning outcomes. No gender differences were found in self-regulation or adaptive functioning outcomes

Analisis Korelasi Kemampuan Berpikir Kreatif Matematik Terhadap Hasil Belajar Matematika Peserta Didik SMP Negeri 3 Lurangung Kuningan Jawa Barat

Penelitian ini bertujuan untuk melihat korelasi antara kemampuan berpikir kreatif matematik dengan hasil belajar matematika peserta didik kelas VII SMP Negeri Luragung Kuningan Jawa Barat. Peserta didik diberikan tes kemampuan berpikir kreatif matematik dan test hasil belajar matematika. Populasi penelitian ini adalah siswa kelas VII SMP Negeri 3 Luragung, Kuningan, Jawa Barat, sedangkan sampel yang diambil adalah siswa kelas VIII A SMP Negeri 3 Luragung, Kuningan, Jawa Barat yang dipilih secara purposive sampling. Instrumen yang digunakan dalam penelitian ini adalah tes kemampuan berpikir kreatif matematik dan hasil belajar matematika. Setelah dilakukan analisis Varians didapat regresi linier dan pengujian keberartian regresi yang signifikan. Dari hasil perhitungan koefisien korelasi sebesar 0,559 dilanjutkan dengan uji t-student diperoleh 3,631. Hal ini berarti terdapat hubungan yang signifikan antara kemampuan berpikir kreatif matematik dengan hasil belajar matematika siswa dan kemampuan berpikir kreatif matematik memberikan kontribusi sebesar 31,2 % terhadap hasil belajar matematika siswa.Kata Kunci : Kreatif, Hasil Belajar Matematika, Kemampuan Berpikir Kreatif Matematik. This study aims to examine the correlations between mathematical creative thinking abilities with mathematics learning outcomes of students of class VII SMP Luragung Kuningan West Java . Learners are given tests of creative thinking skills test results to learn mathematics and mathematics . The study population was a class VII student of SMP Negeri 3 Luragung, Kuningan , West Java , while the samples taken are A class VIII student of SMP Negeri 3 Luragung , Kuningan , West Java, which is selected by purposive sampling. The instrument used in this study is a test of creative thinking skills and mathematical mathematics learning outcomes. After the analysis of variance and linear regression obtained significant regression significance testing. From the calculation of the correlation coefficient of 0.559 followed by Student 's t-test obtained 3.631. This means there is a significant relationship between mathematical creative thinking abilities with mathematics learning outcomes and mathematical creative thinking abilities contributed 31.2 % of the students' mathematicslearning outcomes

Analysis of bioactive phytochemicals and evaluation of antioxidant activity of a medicinal plant, Boerhaavia diffusa L.

Boerhaavia diffusa L. (Family: Nyctaginaceae) commonly known as Punarnava is an herbaceous, spreading vine widely distributed in the tropical and subtropical regions in the world. The plants are a rich source of vitamins, minerals, protein and carbohydrate. The present study was carried out to determine the concentration of some bioactive phytochemicals (ascorbic acid,carotenoids, total phenolics, protein and carbohydrate) and their antioxidant activity in punarnava. Results showed the values for ascorbic acid (16.75±1.72 and 18.86±1.12 mg/100g of Fresh Weight), carotenoids (1.36±0.10 and 1.98±0.11 ìg/g of Fresh Weight), protein (122.975±6.27 and 134.45±6.23 mg/g of dry weight) and carbohydrate (56.67±5.77 and 60.11±5.23 mg/g of dry weight) for aqueous and methanolic of root extracts of B.diffusa respectively. Methanolic root extracts showed greater antioxidant activity than the aqueous extracts using DPPH method

Machine learning applications in astrophysics: Photometric redshift estimation

Machine learning has rose to become an important research tool in the past decade, its application has been expanded to almost if not all disciplines known to mankind. Particularly, the use of machine learning in astrophysics research had a humble beginning in the early 1980s, it has rose and become widely used in many sub-fields today, driven by the vast availability of free astronomical data online. In this short review, we narrow our discussion to a single topic in astrophysics - the estimation of photometric redshifts of galaxies and quasars, where we discuss its background, significance, and how machine learning has been used to improve its estimation methods in the past 20 years. We also show examples of some recent machine learning photometric redshift work done in Malaysia, affirming that machine learning is a viable and easy way a developing nation can contribute towards general research in astronomy and astrophysics.Comment: 8 pages, 5 figures, published in the proceedings of the First International Conference on Computational Science and Data Analytics (COMDATA), 21-24 November 2021, Kuala Lumpur, Malaysi

Therapeutic implications of ofloxacin in the treatment of typhoid fever caused by multiply resistant Salmonella typhi

The antibiotic of choice for the treatment of typhoid fever in most parts of the world is still chloramphenicol. Ampicillin and cotrimoxazole have been used in recent years. Selection of antimicrobials for therapy has been complicated by the emergence of Salmonella typhi strains resistant to the above mentioned antibiotics. Blood and/or bone marrow cultures of 30 adult patients grew S. typhi that was resistant to chloramphenicol, ampicillin and cotrimoxazole. However, these strains were sensitive to cefotaxime, ceftrioxone, aztreonam and ofloxacin. Ofloxacin 400 mg twice a day was given orally to these patients for 14 days. All patients recovered with no untoward side effect. We concluded that ofloxacin can be used as a drug of choice for typhoid fever, in those adult patients who are infected with S. typhi resistant to chloramphenicol, ampicillin and cotrimoxazole

Zenker's Diverticulum: Can Protocolised Measurements with Barium SWALLOW Predict Severity and Treatment Outcomes? The "Zen-Rad" Study

Although barium swallow imaging is established in the investigation of Zenker's diverticulum (ZD), no agreed measurement protocol exists. We developed a protocol for measuring ZD dimensions and aimed to correlate measurements with symptoms and post-operative outcomes. This prospective study included patients with confirmed ZD who underwent flexible endoscopic septal division (FESD) between 2014 and 2018. ZD was confirmed on barium radiology with measurements reviewed by two consultant radiologists. Symptom severity pre- and post-FESD was measured using the Dysphagia, Regurgitation, Complications (DRC) scale. Regression analyses were conducted to identify dimensions associated with therapeutic success, defined as remission (DRC score ≤ 1) 6 months after index FESD. In total, 67 patients (mean age 74.3) were included. Interobserver reliability (intraclass correlation coefficients-ICCs) was greatest for pouch width (0.981) and pouch depth (0.934), but not oesophageal depth (0.018). Male gender (60.9%) was associated with larger pouch height (P = 0.008) and width (P = 0.004). A positive correlation was identified between baseline DRC score and pouch depth (ρ 0.326, P = 0.011), particularly the regurgitation subset score (ρ 0.330, P = 0.020). The index pouch depth was associated with FESD procedure time (rho 0.358, P = 0.041). Therapeutic success was achieved in 64.2% and was associated with shorter pouch height (median 14.5 mm vs. 19.0 mm, P = 0.030), pouch width (median 19.9 mm vs. 28.8 mm, P = 0.34) and cricopharyngeal length (median 20.2 mm vs. 26.3 mm, P = 0.036). ZD dimensions may be feasible and were evaluated using Barium radiology. Specific parameters appear to correlate with severity and post-FESD outcomes, which aid with pre-procedural planning

Boronic Acid Derivatives Targeting HIV-1

A series of novel boronic acid derivatives containing either a pyrimidine or purine base was synthesized. The preparation involved the condensation of 4-bromobutyl boronic acid with the appropriate base. These acyclic nucleosides were designed as potential antiviral agents especially targeting the human immunodeficiency virus. Two analogues, 6-chloro-9-(4-dihydroxyborylbutyl)purine and 2,6-dichloro-9-(4-dihydroxyborylbutyl)purine, exhibited EC50 values of 7.7 µM and 0.99 µM, respectively, in an HIV-1 syncytial plaque reduction assay

Improving Photometric Redshifts by Merging Probability Density Functions from Template-Based and Machine Learning Algorithms

This study aims to improve the photometric redshifts (photo-$z$s) of galaxies by integrating two contemporary methods: template-fitting and machine learning. Finding the synergy between these two methods was not a high priority in the past, but now that our computer processing power and observational accuracy have increased, we deem it worth investigating. We compared two methods to improve galaxy photometric redshift estimations by using the algorithms ANNz2 and BPz on different photometric and spectroscopic samples from the Sloan Digital Sky Survey (SDSS). We find that the photometric redshift performance of ANNz2 (machine learning) is better than that of BPz (galactic templates), and with the utilisation of the merging technique we introduced, we see that there is an improvement in photo-$z$ when the two strategies are consolidated, providing improvements in $\sigma_{RMS}$ and $\sigma_{68}$ up to [0.0265, 0.0222] in the LRG sample and [0.0471, 0.0471] in the Stripe-82 Sample. This simple demonstration can be used for photo-$z$s of galaxies in fainter and deeper sky surveys, and future work is required to prove its viability in these samples.Comment: 14 pages, 5 figure

In Vitro Evaluation and Characterization of Newly Designed Alkylamidophospholipid Analogues as Anti-Human Immunodeficiency Virus Type 1 Agents

Our laboratories first reported two novel classes of complex synthetic lipids, including alkylamidophosphocholines (PC lipid; CP-51) and alkylamidophosphate ester-linked lipid-AZT conjugates (lipid-AZT conjugates; CP-92), with selective and potent activity against human immunodeficiency virus type 1 (HIV-1). To extend these observations, we synthesized additional PC lipids and lipid-AZT conjugates (INK and INK-AZT conjugate) to evaluate their structure-activity relationships by testing for selectivity against infectious wild-type (wt) and drug-resistant HIV-1 replication, virus fusogenic activity and toxicity for mouse bone marrow cells. PC lipid compounds with medium chain lengths at positions 1 and 2 gave an improved selective index (SI). INK-3, with 12 and 8 carbons and INK-15, with 10 and 12 carbons were among the most selective when evaluated in CEM-SS cells. INK-14, a lipid-AZT conjugate where AZT replaced the choline in PC lipid INK-3, gave the highest SI of > 1250 against both infectious wt HIV-1 replication in CEM-SS cells and a clinical isolate in peripheral blood leukocytes. Notably, the PC lipid compounds INK-3 and INK-15, but not the lipid-AZT conjugate INK-14, were potent inhibitors of matched pairs of AZT-sensitive and AZT-resistant HIV-1 clinical isolates. INK-3 also inhibited replication of HIV-2 and TIBO-resistant HIV-1, and inhibited HIV-1-mediated fusogenic activity by 78, 41 and 9% in a dose-dependent manner. The TC50 for mouse bone marrow cells was > 100 micrograms/ml for INK-3 compared to 9.15-14.17 micrograms/ml for CP-51 and 0.142-0.259 microgram/ml for AZT. These data suggest that optimum PC lipid compounds are significantly less toxic than AZT and have high potential as novel therapeutic agents for AIDS