Studies on atmospheric gravity wave activity in the troposphere and lower stratosphere over a tropical station at Gadanki

MST radars are powerful tools to study the mesosphere, stratosphere and troposphere and have made considerable contributions to the studies of the dynamics of the upper, middle and lower atmosphere. Atmospheric gravity waves play a significant role in controlling middle and upper atmospheric dynamics. To date, frontal systems, convection, wind shear and topography have been thought to be the sources of gravity waves in the troposphere. All these studies pointed out that it is very essential to understand the generation, propagation and climatology of gravity waves. In this regard, several campaigns using Indian MST Radar observations have been carried out to explore the gravity wave activity over Gadanki in the troposphere and the lower stratosphere. The signatures of the gravity waves in the wind fields have been studied in four seasons viz., summer, monsoon, post-monsoon and winter. The large wind fluctuations were more prominent above 10 km during the summer and monsoon seasons. The wave periods are ranging from 10 min-175 min. The power spectral densities of gravity waves are found to be maximum in the stratospheric region. The vertical wavelength and the propagation direction of gravity waves were determined using hodograph analysis. The results show both down ward and upward propagating waves with a maximum vertical wave length of 3.3 km. The gravity wave associated momentum fluxes show that long period gravity waves carry more momentum flux than the short period waves and this is presented

KNEE OSTEOARTHRITIS PREDICTION DRIVEN BY DEEP LEARNING AND THE KELLGREN-LAWRENCE GRADING

Degenerative osteoarthritis of the knee (KOA) affects the knee compartments and worsens over 10–15 years. Knee osteoarthritis is the major cause of activity restrictions and impairment in older persons. Clinicians' expertise affects visual examination interpretation. Hence, achieving early detection requires fast, accurate, and affordable methods. Deep learning (DL) convolutional neural networks (CNN) are the most accurate knee osteoarthritis diagnosis approach. CNNs require a significant amount of training data. Knee X-rays can be analyzed by models that use deep learning to extract the features and reduce number of training cycles. This study suggests the usage of DL system that is based on a trained network on five-class knee X-rays with VGG16, SoftMax (Normal, Doubtful, Mild, Moderate, Severe). Two deep CNNs are used to grade knee OA instantly using the Kellgren-Lawrence (KL) methodology. The experimental analysis makes use of two sets of 1650 different knee X-ray images. Each set consists of 514 normal, 477 doubtful, 232 mild, 221 moderate, and 206 severe cases of osteoarthritis of the knee. The suggested model for knee osteoarthritis (OA) identification and severity prediction using knee X-ray radiographs has a classification accuracy of more than 95%, with training and validation accuracy of 95% and 87%, respectively

Synthesis of N-(3-arylprop-2-ynyl)substituted olanzapine derivatives as potential inhibitors of PDE4B

The linkage between dopamine D2 receptors and PDE activity via cAMP prompted us to design a series of novel N-(3-arylprop-2-ynyl)substituted olanzapine derivatives as potential inhibitors of PDE4B. The target compounds were conveniently prepared by using a simple and inexpensive method involving Pd/C-mediated CC bond forming reaction under Sonogashira conditions. A number of compounds were synthesized by using this strategy in good yields. Some of the compounds showed promising inhibition of PDE4B when tested in vitro that was supported by the docking studies

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Long-term variability of the low latitude mesospheric SAO and QBO and their relation with stratospheric QBO

Long term variations of low-latitude mesospheric semi-annual oscillation (MSAO) and quasi-biennial oscillation (MQBO) in the zonal wind are studied using observations available from 1977 to 2006. The MQBO showed large inter-annual variability in the phase difference between 77.5 km and 72.5 km indicating such variability in eddy viscosity. Association of these oscillations with stratospheric quasi-biennial oscillation (SQBO) is investigated. In general, the MQBO at 77.5 km is out-of-phase with SQBO and this relation fails during strong and long SQBO. The MSAO at 72.5 km and 77.5 km generally shows strong westward phase during strong eastward phase of SQBO. The most striking feature observed in the present study is the strong modulation of the MSAO by MQBO revealing a non-linear type of interaction with presence of sidebands of the MSAO

Study on special ABL features observed over Tirupati using sodar

47-52A monostatic acoustic sounder (sodar) has been developed in the Department of Physics, Sri Venkateswara University, Tirupati, for the study of dynamical behaviour of the atmospheric boundary layer (ABL) phenomena over Tirupati. The infrasonic pressure variations have been recorded near sodar site using a microbarograph. Short-period waves/down-flow structures (rare phenomena) caused due to onset of drainage flow are reported. The short-period wave (fluctuations) is usually associated with either convective plume activity or ground-based inversions in the evening transition hours. It is inferred that these short-period waves are caused due to the onset of nocturnal drainage flows under convection/thermal inversion of variable depth

INVESTIGATION OF TENSILE AND IMPACT BEHAVIOUR OF ABACA-RAFFIA HYBRID COMPOSITE

ABSTRACT Current technological development forces the industries to find new alternate and non-conventional materials that may replace conventional materials. Hence, industries are aiming to develop composite materials that are made from two or more constituent materials with significantly different physical and chemical properties. Hence, the composite materials have better properties than their constituent materials. In this paper an attempt has been made to fabricate and investigate the tensile and impact properties natural fiber composites made up of abaca and raffia fibers with three different compositions. The method adapted is hand layup process. The result shows that the hybrid composite made up of abaca and raffia have better properties than mono fiber composites. Failure morphology analysis is done using scanning electron microscope on the tested specimens

Climatology of low-latitude mesospheric echo characteristics observed by Indian mesosphere, stratosphere, and troposphere radar

Low-latitude mesospheric echo characteristics are investigated using data collected during June 1994 to July 2005 (11 years) by the Indian mesosphere, stratosphere, and troposphere radar located at Gadanki (13.5°N, 79.2°E). Mesospheric echoes are frequently observed during 1000-1530 hrs (local time) in the height range of 68-78 km and are found to be highly intermittent in both space and time, consistent with those reported elsewhere. Although echoes are observed throughout the year, strong seasonal dependence has been observed in both echo occurrence and signal-to-noise ratio (SNR). Percentage occurrence (PO) of mesospheric echoes shows two maxima, one during late March equinox and early summer, and another during September. However, corresponding SNR suggests that strong echoes occur in both equinoxes with a minimum during winter. A clear semiannual variation is observed in PO of echoes with a peak occurring during the months of May and October. Similar variation is observed in SNR with peaks in March and September-November. These features are quite different from those observed at midlatitudes and high latitudes. Annual oscillation seems to fit well above 78 km and below 68 km, although on many occasions, occurrence of echo is poor at these heights. The ratio of vertical to off-vertical beam SNR (which could be taken as a measure of aspect sensitivity) was close to unity at these heights, indicating that scattering is due to turbulence-generated refractive index fluctuations. A positive correlation (R = 0.37) between PO and solar activity is observed, whereas a negative correlation (R = -0.55) is found between SNR and solar activity. The echo characteristics observed have been compared in detail with those reported from midlatitudes and high latitudes. The mechanisms behind the observed features are discussed in the light of mesospheric temperature inversions (MTIs), which are often noticed at this location, and wave breaking at these altitudes