Equatorial counter electrojets and polar stratospheric sudden warmings - a classical example of high latitude-low latitude coupling

Favored occurrences of Equatorial Counter Electrojets (CEJs) with a quasi 16-day periodicity over Trivandrum (8.5° N, 76.5° E, 0.5° N diplat.) in association with the polar Stratospheric Sudden Warming (SSW) events are presented. It is observed that, the stratospheric temperature at ˜30 km over Trivandrum shows a sudden cooling prior to the SSWs and the CEJs of maximum intensity which occurs around this time. In general stronger CEJs are associated with more intense SSW events. The stratospheric zonal mean zonal wind over Trivandrum also exhibits a distinctly different pattern during the SSW period. These circulation changes are proposed to be conducive for the upward propagation of the lower atmospheric waves over the equatorial latitudes. The interaction of such waves with the tidal components at the upper mesosphere and its subsequent modification are suggested to be responsible for the occurrence of CEJs having planetary wave periods

Explaining Deep Face Algorithms through Visualization: A Survey

Although current deep models for face tasks surpass human performance on some benchmarks, we do not understand how they work. Thus, we cannot predict how it will react to novel inputs, resulting in catastrophic failures and unwanted biases in the algorithms. Explainable AI helps bridge the gap, but currently, there are very few visualization algorithms designed for faces. This work undertakes a first-of-its-kind meta-analysis of explainability algorithms in the face domain. We explore the nuances and caveats of adapting general-purpose visualization algorithms to the face domain, illustrated by computing visualizations on popular face models. We review existing face explainability works and reveal valuable insights into the structure and hierarchy of face networks. We also determine the design considerations for practical face visualizations accessible to AI practitioners by conducting a user study on the utility of various explainability algorithms

Role of gravity wave like seed perturbations on the triggering of ESF - a case study from unique dayglow observation

First observational evidence, from the Indian longitudes, for the presence of gravity wavelike perturbations with periods of 20-30 min, acting as probable seeds for Equatorial Spread F (ESF) irregularities is described. The study is based on the daytime optical measurements of the mesopause temperature and the intensity of the thermospheric O(1D) 630.0 nm dayglow emissions using the unique MultiWavelength Dayglow PhotoMeter from Trivandrum (8.5° N; 77° E; dip lat ˜0.5° N), a dip equatorial station. Measurements during the equinoctial months of a solar maximum (2001) and a solar minimum year (2006) have been used in this study. It is shown that under identical background ionospheric conditions within a solar epoch, the power of the gravity waves have a deterministic role in the generation of ESF. The mesopause temperature simultaneously observed, indicate that possible source regions for these perturbations lie in the lower atmosphere

Low-Cost Transfer Learning of Face Tasks

Do we know what the different filters of a face network represent? Can we use this filter information to train other tasks without transfer learning? For instance, can age, head pose, emotion and other face related tasks be learned from face recognition network without transfer learning? Understanding the role of these filters allows us to transfer knowledge across tasks and take advantage of large data sets in related tasks. Given a pretrained network, we can infer which tasks the network generalizes for and the best way to transfer the information to a new task

Rare association of multiple etiologies in a severe oligoasthenospermic male

We report a rare case of a 30 year old man diagnosed with severe oligoasthenospermia, where the infertile condition is traced back to a multiple etiologies. Routine semen analysis and sperm function tests followed by hormone analysis are carried out to diagnose the condition as well as the severity. The initial findings prompt us to perform Ultrasound scanning of testis and Trans Rectal Ultrasound Scanning (TRUS) to check the anatomical and functional status of the accessory reproductive organs. Semen analysis and sperm function tests provide an insight into the severity of the condition. The hormonal analysis, Ultrasound scanning of testis and TRUS of accessory reproductive glands confirms the association of hormonal imbalance, testis and accessory gland defects which results in the observed infertile condition with severe sperm defects. A thorough investigation of infertile subjects is essential for appropriate diagnosis and effective personalized treatment owing to the probability of multiple etiologies. Incomplete diagnosis can have adverse effects in treatment and Assisted Reproductive Techniques (ART)

ARUBA: An Architecture-Agnostic Balanced Loss for Aerial Object Detection

Deep neural networks tend to reciprocate the bias of their training dataset. In object detection, the bias exists in the form of various imbalances such as class, background-foreground, and object size. In this paper, we denote size of an object as the number of pixels it covers in an image and size imbalance as the over-representation of certain sizes of objects in a dataset. We aim to address the problem of size imbalance in drone-based aerial image datasets. Existing methods for solving size imbalance are based on architectural changes that utilize multiple scales of images or feature maps for detecting objects of different sizes. We, on the other hand, propose a novel ARchitectUre-agnostic BAlanced Loss (ARUBA) that can be applied as a plugin on top of any object detection model. It follows a neighborhood-driven approach inspired by the ordinality of object size. We evaluate the effectiveness of our approach through comprehensive experiments on aerial datasets such as HRSC2016, DOTAv1.0, DOTAv1.5 and VisDrone and obtain consistent improvement in performance.Comment: Accepted to WACV 202

Daytime sodium airglow emission measurements over Trivandrum using a scanning monochromator: first results

This paper presents measurement of daytime Sodium (Na) airglow emissions at 589.6 nm wavelength using a ground based 1-m scanning monochromator from Trivandrum (8.5° N, 77° E, 0.5° N dip latitude), a near-equatorial station in India. The Na emission intensity exhibits significant temporal variability within a day and from one day to another. The Na intensity has been compared with the daytime OH airglow intensity at 731.6 nm simultaneously measured using the unique Multiwavelength Dayglow Photometer (MWDPM). The temporal variabilities of the Na and OH intensities corroborate each other in most of the occasions without any appreciable time delay, although a small time delay up to ˜10 min has been observed at times. It appears that the variability of daytime Na emissions is influenced too by the photo-chemical excitations. The observed similarities in the Na and OH intensities are believed to be due to the similar roles played by [O] and O3 (in their photo-chemical excitations) and the dynamics occurring at about the same altitude region (˜90 km). It has also been found that the gravity waves play significant role in producing the short-scale oscillations in these emissions