GPS observations of ionospheric TEC variations over Nepal during 22 July 2009 solar eclipse

As the study of ionospheric behavior during various solar activities is an important task, various studies of ionospheric changes during eclipse events have been widely performed in the different regions of the globe. This paper investigates the ionospheric responses to the solar eclipse on 22 July 2009 over Nepal using the total electron content (TEC) measured by dual-frequency Global Positioning System (GPS) receivers. The time-averaged Vertical TEC (vTEC) of ten GPS stations from Nepal is analyzed and it is found that the value of ionospheric TEC decreases due to the reduction of ionizing radiation. In addition, the deviation in the TEC value on eclipse day from the mean vTEC value of the top five quietest days is found to lie in the range ~1–5 TECu at those regions which were associated with the partial eclipse shadow. On the other hand, the region with the total eclipse (BRN2 and RMTE) faced ~6–7 TECu on average reduction in the TEC value. Considering that the eclipse of 22 July 2009 occurred just at sunrise in the Nepalese zone, a maximum reduction of about 5 TECu is very significant. Higher deviation in TEC is therefore linked with the path of totality and the obscuration rate. This study reveals that the ionospheric TEC over Nepal was altered by wave-like energy and momentum transport, as well as obscuration of the solar disc due to the partial and total solar eclipse. Furthermore, the cross-correlation results presented similar type signatures of the eclipse-induced ionospheric modification over Nepal. This research work serves a crucial future reference for the comparative study of change of ionospheric TEC variability over the Nepal region during Eclipse event

Novel Somatostatin Receptor Subtype-4 Agonist Mitigates Microglia Inflammatory Activation

Microgliosis is a hallmark of Alzheimer’s disease (AD) and is associated with inflammatory activation of microglia. Discovery of new molecules capable of mitigating the inflammatory response may provide a viable means to treat AD. Somatostatin receptor subtype-4 (SST4) shows particular promise as a treatment target for AD given its microglia and neuronal localization in the brain. A SST4 agonist has the potential to lessen microglia inflammatory activity. This research evaluated the novel SST4 agonist SM-I-26 in its ability to modulate microglia inflammatory responses and enhance mechanisms affiliated with the breakdown of amyloid-beta peptide (Aβ). The selective and high affinity SST4 agonist SM-I-26 was evaluated in BV2 mouse microglia cells concurrent with inflammatory challenge via lipopolysaccharide (LPS) treatment. After plating for 24 hrs., cells were treated for another 24 hrs. with SM-I-26 (0, 10, 1000 nM) against LPS (0, 10, 100 ng/mL). Cell viability/proliferation (alamarBlue assay), nitrite (surrogate of nitric oxide, Griess assay) output in media, and mRNA expression (RT-qPCR) of genes associated with SST4, inflammation, Aβ phagocytosis, and Aβ degrading enzymes were measured. Two-way ANOVAs with Tukey post-hoc tests were used to determine significance (α= 0.05). SM-I-26 decreased BV-2 cell viability/proliferation, while LPS increased viability/proliferation. A significant interaction between LPS and SM-I-26 was found on mean nitrite. Within no LPS, mean nitrite was similar across all concentrations of SM-I-26. With 10 ng/ml LPS, nitrite output trended towards a decrease with both 10 and 1000 nM SM-I-26 compared to vehicle. Within 100 ng/ml LPS, both 10 and 1000 nM SM-I-26 significantly decreased nitrite compared to vehicle control. The mRNA expression of key genes associated with microglia inflammation, SST4, function, and Aβ clearance were next evaluated. A significant interaction was found between SM-I-26 and LPS for Sst4. Sst4 mRNA expression increased with SM-I-26 treatment under both basal and inflammatory conditions. The Aβ degrading enzymes Neprilysin and insulin degrading enzyme showed no changes in mRNA expression across treatments. However, SM-I-26 treatment significantly increased angiotensin converting enzyme mRNA expression under basal conditions at highest concentration of SM-I-26. Similar upregulation pattern was observed for endothelin converting enzyme-1, while endothelin converting enzyme-2 showed a decline with treatment. Interactions were found for macrophage scavenger receptor-1 (Msr1) and triggering receptor expressed on myeloid cells-1 (Trem1). Increased expression of Msr1 by SM-I-26 under non-inflammatory and 10 ng/mL LPS-stimulated conditions implicate enhanced capacity to clear Aβ. The SM-I-26 dose-dependently downregulated Trem1, identifying potential beneficial effects on anti-inflammatory pathways. SM-I-26 treatment increased catalase with and without LPS, but not their interactions. This overexpression of catalase could be neuroprotective against Aβ toxicity. Significant interactions were found between SM-I-26 and LPS for tumor necrosis factor-α (Tnf-α) and interleukin-1β (IL1β). The 1000 nM SM-I-26 significantly decreased Tnf-α mRNA expression under basal and inflammatory conditions, with 10 nM SM-I-26 decreasing Tnf-α only with the highest LPS concentration. The 10 and 1000 nM SM-I-26 decreased IL-1β expression at the highest LPS concentration. The 10 nM SM-I-26 decreased interleukin-6 with low and high dose LPS treatment. The anti-inflammatory cytokine interleukin-10 was upregulated by 10 nM SM-I-26 under both basal and inflammatory conditions, but not at the higher 1000 nM concentration. Data indicates a dose-range viability respective to effects on cytokines. These results show treatment with SST4 agonist SM-I-26 exerts an anti-inflammatory and antioxidant activity in microglia with capacity to modulate cell surface proteins associated with Aβ phagocytosis. Treatment with SST4 agonist SM-I-26 generally shifted the activation state of the LPS challenged BV-2 microglia from a pro-inflammatory M1 state to anti-inflammatory/pro-phagocytic M2 state. Data support potential use of SST4 agonist for AD treatment

Change of Spectral Properties of Magnetic Field Fluctuations across Different Types of Interplanetary Shocks

The interaction between interplanetary (IP) shocks and the solar wind has been studied in the past for the understanding of energy dissipation mechanisms within collisionless plasmas. Compared to the study of fast shocks, other types of IP shocks, including slow mode shocks (i.e., fast forward, fast reverse, slow forward, and slow reverse shocks) remained largely unnoticed. We analyze magnetic field fluctuations observed by the Wind spacecraft from 1995 to 2021 upstream and downstream of the IP shocks using a continuous wavelet transform. The evolution of spectral indices in the ion inertial and transition ranges and the changes in distributions of characteristic ion length scales with respect to the spectral break and proton beta are presented. We found that spectral indices in both inertial and transition ranges and the characteristic length scale distributions are statistically conserved across three types of IP shocks, suggesting that mechanisms associated with the energy dissipation are unaffected by the shocks. The results obtained for the transition range of fast reverse shocks show a larger difference between upstream and downstream plasmas and this will be further studied

Physical, mental and social status after COVID-19 recovery in Nepal: A mixed method study.

BackgroundNepal has been devastated by an unprecedented COVID-19 outbreak, affecting people emotionally, physically, and socially, resulting in significant morbidity and mortality. Approximately 10% of COVID-19 affected people have symptoms that last more than 3-4 weeks and experience numerous symptoms causing an impact on everyday functioning, social, and cognitive function. Thus, it is vital to know about the recovered patient's health status and undertake rigorous examinations to detect and treat infections. Hence, this study aims to assess the health status of COVID-19 post-recovery patients in Nepal.MethodA descriptive cross-sectional mixed-method study was conducted in all seven provinces of Nepal. A total of 552 interviews were conducted for the quantitative study, and 25 in-depth interviews were conducted for the qualitative study among above 18 years COVID-19-recovered patients. The data was gathered over the phone through the purposive sampling method The results of a descriptive and thematic analysis were interpreted.FindingThe majority (more than 80%) of the recovered patients could routinely perform household duties, activities outside the home, and financial job accounting. However, a few of them required assistance in carrying out all of those tasks. Prior and then after COVID-19 infection, smoking habits reduced by about one-tenth and alcohol intake decreased by a twelve percent. A qualitative finding revealed that the majority of COVID-19 symptomatic patients experienced a variety of physical symptoms such as fever, headache, body pain, fatigue, tiredness, sore throat, cough, loss of taste, loss of smell, sneezing, loss of appetite, and difficulty breathing, while others felt completely fine after being recovered. Furthermore, there was no variation in the daily functional activities of the majority of the recovered patients, while a few were found conducting fewer activities than usual because they were concerned about their health. For social health, quantitative data indicated that more than half of the participants' social health was severely impacted. According to the IDI, the majority of the interviewees perceived society's ignorance and misbehavior. Family members were the most often solicited sources of support. Some participants got care and assistance, but the majority did not get affection or love from their relatives. Moreover, regarding mental health, 15 percent of participants had repeated disturbing and unwanted thoughts about COVID-19 after being recovered, 16 percent tried to avoid information on COVID-19 and 7 .7 percent of people had unfavorable ideas or sentiments about themselves. More than 16 percent of participants reported feeling some level of stress related to the workplace and home. While in-depth interviews participants revealed that COVID-infected patients who were asymptomatic didn't experience any emotional change in them but recovered patients who are symptomatic symptoms had anxiety and still being conscious of COVID-19 in fear of getting infected again Additionally, it was discovered that participants' mental health is influenced by ignorance of society, as well as by fake news posted to social media.ConclusionCOVID-19 infection has had an impact on physical, mental, and social well-being. Hence, to aid in the early recovery of COVID-19 patients, provision of evaluating and reporting the clinical features, early detection and management of long COVID case is needed from the local and provincial and central government of Nepal

GPS Observations of Ionospheric TEC Variations Over Nepal During 22 July 2009 Solar Eclipse

As the study of ionospheric behavior during various solar activities is an important task, various studies of ionospheric changes during eclipse events have been widely performed in the different regions of the globe. This paper investigates the ionospheric responses to the solar eclipse on 22 July 2009 over Nepal using the total electron content (TEC) measured by dual-frequency Global Positioning System (GPS) receivers. The time-averaged Vertical TEC (vTEC) of ten GPS stations from Nepal is analyzed and it is found that the value of ionospheric TEC decreases due to the reduction of ionizing radiation. In addition, the deviation in the TEC value on eclipse day from the mean vTEC value of the top five quietest days is found to lie in the range ~1–5 TECu at those regions which were associated with the partial eclipse shadow. On the other hand, the region with the total eclipse (BRN2 and RMTE) faced ~6–7 TECu on average reduction in the TEC value. Considering that the eclipse of 22 July 2009 occurred just at sunrise in the Nepalese zone, a maximum reduction of about 5 TECu is very significant. Higher deviation in TEC is therefore linked with the path of totality and the obscuration rate. This study reveals that the ionospheric TEC over Nepal was altered by wave-like energy and momentum transport, as well as obscuration of the solar disc due to the partial and total solar eclipse. Furthermore, the cross-correlation results presented similar type signatures of the eclipse-induced ionospheric modification over Nepal. This research work serves a crucial future reference for the comparative study of change of ionospheric TEC variability over the Nepal region during Eclipse event