Occurrence of canine mammary and skin/ subcutaneous neoplasms in and around Thrissur district of Kerala during 2017-2020: A review of 265 cases

The study was conducted in 265 clinical cases of mammary and skin/ subcutaneous neoplasms in dogs presented to University Veterinary Hospitals Mannuthy and Kokkalai during a period of 36 months from October 2017 to September 2020. Mammary neoplasms were found more in females (51.7 per cent) than in males whereas skin and subcutaneous neoplasms were found more in male dogs (48.3 per cent). The maximum occurrence of neoplasms was recorded in the age group of eight to twelve years (38.5 per cent) whereas least occurrence was noticed in the age group up to four years (9 per cent). Labrador and Rottweiler breeds were found more affected with neoplasms (38 per cent each) with highest occurrence of mammary neoplasms in inguinal mammary glands (35.03 per cent) and highest occurrence of skin/ subcutaneous neoplasms on sites involving trunk region (14.06 per cent cases). Eighty-three per cent of the neoplasm cases in the present study were pet dogs with a greater number of dogs maintained in outdoor kennels and 17 per cent of neoplasm was found in free-roaming dogs rescued from streets. Out of total 265 dogs, 37.73 per cent dogs were found to be having commercial dog food as their main feed and 32 per cent dogs were fed with a mixed diet of homemade food and commercial dog food. Among the cases, 14.71 per cent dogs had a previous history of cancer surgery

Climatology of Spread F over Tucumán from Massive Statistical Analysis of Autoscaled Data

Automatic ionogram interpretation methods developed for real-time ionospheric monitoring can be applied in retrospective studies to analyze large quantities of data. The Autoscala software, implemented for such a purpose, includes a routine for automatic detection of diffused echoes known as spread F, which appear in ionograms due to the presence of ionospheric irregularities along the radio signal path. The main objective of this routine is to reject bad quality ionograms. This new capability was used in a climatological study including a large number of ionograms recorded at the low-latitude ionospheric station of Tucumán (26.9° S, 294.6° E, magnetic latitude 15.5° S, Argentina). The study took into account different levels of geomagnetic and solar activity from 2012 to 2020. The results demonstrate the capability of Autoscala to capture the main signature characteristics of spread F and the temporal evolution of the ionosphere peak heigh hmF2, capturing the post-sunset plasma surge that precedes development of spread F. Maximum occurrence of spread F is observed in local summer, with a tendency to shift before midnight with increasing solar activity. Other new climatological details that emerged from the study are illustrated and briefly discussed, dealing with connection with geomagnetic activity, and morning hmF2 behavior after extremely marked nighttime spread F occurrence.

Microphysical Characteristics of Rainfall Observed by a 2DVD Disdrometer during Different Seasons in Beijing, China

The seasonal variations of raindrop size distribution (DSD) and rainfall are investigated using three-year (2016–2018) observations from a two-dimensional video disdrometer (2DVD) located at a suburban station (40.13°N, 116.62°E, ~30 m AMSL) in Beijing, China. The annual distribution of rainfall presents a unimodal distribution with a peak in summer with total rainfall of 966.6 mm, followed by fall. Rain rate (R), mass-weighted mean diameter (Dm), and raindrop concentration (Nt) are stratified into six regimes to study their seasonal variation and relative rainfall contribution to the total seasonal rainfall. Heavy drizzle/light rain (R2: 0.2~2.5 mm h−1) has the maximum occurrence frequency throughout the year, while the total rainfall in summer is primarily from heavy rain (R4: 10~50 mm h−1). The rainfall for all seasons is contributed primarily from small raindrops (Dm2: 1.0~2.0 mm). The distribution of occurrence frequency of Nt and the relative rainfall contribution exhibit similar behavior during four seasons with Nt of 10~1000 m−3 registering the maximum occurrence and rainfall contributions. Rainfall in Beijing is dominated by stratiform rain (SR) throughout the year. There is no convective rainfall (CR) in winter, i.e., it occurs most often during summer. DSD of SR has minor seasonal differences, but varies significantly in CR. The mean values of log10Nw (Nw: mm−1m−3, the generalized intercept parameter) and Dm of CR indicate that the CR during spring and fall in Beijing is neither continental nor maritime, at the same time, the CR in summer is close to the maritime-like cluster. The radar reflectivity (Z) and rain rate (?) relationship (Z = ?R?) showed seasonal differences, but were close to the standard NEXRAD Z-R relationship in summer. The shape of raindrops observed from 2DVD was more spherical than the shape obtained from previous experiments, and the effect of different axis ratio relations on polarimetric radar measurements was investigated through T-matrix-based scattering simulations.

Storm Time EMIC Waves Observed by Swarm and Van Allen Probe Satellites

<p>The temporal and spatial evolution of electromagnetic ion cyclotron (EMIC) waves during<br>the magnetic storm of 21–29 June 2015 was investigated using high-resolution magnetic field observations<br>from Swarm constellation in the ionosphere and Van Allen Probes in the magnetosphere. Magnetospheric<br>EMIC waves had a maximum occurrence frequency in the afternoon sector and shifted equatorward during<br>the expansion phase and poleward during the recovery phase. However, ionospheric waves in subauroral<br>regions occurred more frequently in the nighttime than during the day and exhibited less obvious<br>latitudinal movements. During the main phase, dayside EMIC waves occurred in both the ionosphere<br>and magnetosphere in response to the dramatic increase in the solar wind dynamic pressure. Waves were<br>absent in the magnetosphere and ionosphere around the minimum SYM-H. During the early recovery<br>phase, He<sup>+ </sup>band EMIC waves were observed in the ionosphere and magnetosphere. During the late<br>recovery phase, H<sup>+</sup> band EMIC waves emerged in response to enhanced earthward convection during<br>substorms in the premidnight sector. The occurrence of EMIC waves in the noon sector was affected by<br>the intensity of substorm activity. Both ionospheric wave frequency and power were higher in the summer<br>hemisphere than in the winter hemisphere. Waves were confined to an MLT interval of less than 5 hr with a<br>duration of less than 186 min from coordinated observations. The results could provide additional insights<br>into the spatial characteristics and propagation features of EMIC waves during storm periods</p>

Characteristic of daytime F-region backscatter plume structures over low latitude of China

<p>Ionospheric F‐region irregularity backscatter plumes are commonly regarded as a nighttime phenomenon at equatorial and low latitudes. At daytime, there are very few reported cases of F‐region backscatter echoes. It is still not clear what caused the daytime echoes. In order to understand the occurrence of daytime F‐region echoes, we carried out an experiment with Sanya VHF radar (18.4°N, 109.6°E, dip lat. 12.8°N) during November 2016 to August 2020. Some basic characteristics were released: (1) The daytime F‐region echoing structures have an unexpected high occurrence in June solstice of solar minimum. (2) The echoing structures could appear at any time during 0700–1800 LT, with a maximum occurrence around 0900 LT. (3) The echoing structures appeared mostly above 350 km altitude, extending up to 650 km or more (F region topside) with apparent westward drifts at times. Radar interferometry and ICON satellite in situ results show that the daytime F‐region echoes were from plume structures consisting of field‐aligned irregularities. It is suggested that the plume structures could be remnants of equatorial plasma bubble (EPB) irregularities generated on the previous night around 100–125°E. They rise to high altitudes and drift zonally together with background plasma, causing the daytime F‐region backscattering structure over Sanya. With simultaneous observations of several VHF radars at different locations, satellite in-situ measurements and/or EPB model, the dynamics of daytime F-region backscatter plume structures could be better understood in the future.</p>

Long-Term Characteristics of Midlatitude Mesosphere Summer Echoes (MSE) Observed with a VHF Radar at Wakkanai, Japan (45.4ºN)

Midlatitude mesosphere summer echoes (MSE) at the VHF band (VHF-MSE) were observed for 13 years (2000-2002 and 2009-2018) with a 46.5 MHz radar at Wakkanai, Japan (45.4ºN, 141.8ºE). VHF-MSE are active during June-July and appear only in the daytime mainly at altitudes of 80-88 km with a maximum occurrence at 85 km and altitude extents of 1-4 km for a duration of about half an hour or more. The VHF-MSE occurrences are positively correlated with solar activity, but not with geomagnetic activity except for very high activity. Such long-term characteristics are mostly consistent with past VHF-MSE observations at higher midlatitudes in Europe. No VHF-MSE were observed in 2002, 2014 and 2018, possible reasons for which are discussed. It is shown that cold ice particles in the upper mesosphere inducing MSE are advected from high latitudes to midlatitudes with equatorward wind. Thus, the MSE occurrences over Wakkanai are fundamentally controlled by both the solar activity and equatorward ice particle advection. One example of MSE at the HF band (HF-MSE) is presented to discuss spatial and temporal relationship between VHF-MSE and HF-MSE.

Possible mechanisms of summer cirrus clouds over the Tibetan Plateau

The geographical distributions of summertime cirrus with different cloud top heights above the Tibetan Plateau are investigated by using the 2012–2016 Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data. The cirrus clouds with different cloud top heights exhibit an obvious difference in their horizontal distribution over the Tibetan Plateau (TP). The maximum occurrence for cirrus with a cloud top height less than 9 km starts over the western plateau and moves up to the northern regions when cirrus is between 9 and 12 km. Above 12 km, the maximum occurrence of cirrus retreats to the southern fringe of the plateau. Three kinds of formation mechanisms – large-scale orographic uplift, ice particle generation caused by temperature fluctuation, and remnants of overflow from deep-convective anvils – dominate the formation of cirrus at less than 9 km, between 9 and 12 km, and above 12 km, respectively.

Changes in Hydromorphological Conditions in an Endorheic Lake Influenced by Climate and Increasing Water Consumption, and Potential Effects on Water Quality

The study aims to analyse changes in the morphological conditions of the endorheic Lake Borówno (39.06 ha) that occurred in the 20th century and early 21st century. The analysis was based on bathymetric measurements carried out in 2018 and cartographic materials, and performed using QGIS 3.10 and SAGA GIS 6.4 software. Moreover, changes in physical (temperature, transparency), chemical (dissolved oxygen, phosphorus, and nitrogen content) and biological (chlorophyll a, phytoplankton) parameters were analysed based on the results of measurements conducted by the Voivodeship Inspectorate of Environment Protection (VIEP) in Bydgoszcz in the period 1984–2017. It was found that Lake Borówno is subject to a constant reduction in surface area and volume, the rate of which increased in the second decade of the 21st century. The lake’s progressive disappearance results from the co-occurrence of hydrological drought over the last several years and an increase in the use of groundwater resources. A decrease in the maximum depth of the lake entails a change in temperature distribution in the vertical profile, which contributes to the tendency toward the lake transforming into an unstratified reservoir. The increase in water temperature affects oxygen content in the bottom water, improves water transparency, and influences the maximum occurrence of chlorophyll a in spring.

High frequency radio emissions as a manifestation of physical processes in the auroral plasma

<p>The Earth’s auroral region and its close neighbourhood is the origin of strong radio emissions caused by complex physical plasma processes. Among them we can list auroral hiss, auroral roar, auroral medium frequency (MF) burst, and auroral kilometric radiation (AKR).  Analysis of such emissions can provide information about magnetospheric structure and dynamics. </p><p>In this work we present selected cases of Earth’s AKR-like radio emissions observed by RELEC  and mission at the top side ionosphere leyers. The emissions are seen at frequencies of the order of hundreds of kHz in the ionosphere, just below the auroral oval and  can be observed not only in disturbed geomagnetic conditions, but also during quiet periods. The maximum occurrence is at ∼ 75 ◦ invariant latitude and can have extent up to ∼ 11 ◦ in invariant latitude.</p><p> </p>

Investigation of the Occurrence of Nighttime Topside Ionospheric Irregularities in Low-Latitude and Equatorial Regions Using CYGNSS Satellites

By using multi-satellite observations of the L1 signal-to-noise ratio (SNR) from the Cyclone Global Navigation Satellite System (CYGNSS) taken in 2017, we present the occurrence of nighttime topside ionospheric irregularities in low-latitude and equatorial regions. The most significant finding of this study is the existence of longitudinal structures with a wavenumber 4 pattern in the topside irregularities. This suggests that lower atmospheric waves, especially a daytime diurnal eastward-propagating zonal wave number-3 nonmigrating tide (DE3), might play an important role in the generation of topside plasma bubbles during the low solar minimum. Observations of scintillation events indicate that the maximum occurrence of nighttime topside ionospheric irregularities occurs on the magnetic equator during the equinoxes. The current work, which could be regarded as an important update of the previous investigations, would be readily for the further global analysis of the topside ionospheric irregularities.