Whistlers and Related Ionospheric Phenomena

In many traditional societies, women’s age at marriage acts simultaneously as a gateway to new family roles and the likelihood of producing offspring. However, inadequate attention has previously been given to the broader health and social implications of variability in women’s marriage age for public health. Biomedical scientists have primarily been concerned with whether the onset of reproduction occurs before the woman is adequately able to nurture her offspring and maintain her own health. Social scientists have argued that early marriage prevents women from attaining their rightful education, accessing employment and training opportunities, developing social relationships with peers and participating in civic life. The aim of this review article is to provide comprehensive research evidence on why women’s marriage age, independent of age at first childbirth, is a crucial issue for public health. It focuses on data from four South Asian countries, Bangladesh, India, Nepal and Pakistan, in which marriage is near-universal and where a large proportion of women still marry below the UN prescribed minimum marriage age of 18 years. Using an integrative perspective, we provide a comprehensive synthesis of the physiological, bio-demographic and socio-environmental drivers of variable marriage age. We describe the adverse health consequences to mothers and to their offspring of an early age at marriage and of childbearing, which include malnutrition and high rates of morbidity and mortality. We also highlight the complex association of marriage age, educational attainment and low societal status of women, all of which generate major public health impact. Studies consistently find a public health dividend of increased girls’ education for maternal and child nutritional status and health outcomes. Paradoxically, recent relative increases in girls’ educational attainment across South Asia have had limited success in delaying marriage age. This evidence suggests that in order for public health initiatives to maximize the health of women and their offspring, they must first address the factors that shape the age at which women marry.

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Women's Marriage Age Matters for Public Health: A Review of the Broader Health and Social Implications in South Asia.

Plant secondary metabolites (PSMs) are vital for human health and constitute the skeletal framework of many pharmaceutical drugs. Indeed, more than 25% of the existing drugs belong to PSMs. One of the continuing challenges for drug discovery and pharmaceutical industries is gaining access to natural products, including medicinal plants. This bottleneck is heightened for endangered species prohibited for large sample collection, even if they show biological hits. While cultivating the pharmaceutically interesting plant species may be a solution, it is not always possible to grow the organism outside its natural habitat. Plants affected by abiotic stress present a potential alternative source for drug discovery. In order to overcome abiotic environmental stressors, plants may mount a defense response by producing a diversity of PSMs to avoid cells and tissue damage. Plants either synthesize new chemicals or increase the concentration (in most instances) of existing chemicals, including the prominent bioactive lead compounds morphine, camptothecin, catharanthine, epicatechin-3-gallate (EGCG), quercetin, resveratrol, and kaempferol. Most PSMs produced under various abiotic stress conditions are plant defense chemicals and are functionally anti-inflammatory and antioxidative. The major PSM groups are terpenoids, followed by alkaloids and phenolic compounds. We have searched the literature on plants affected by abiotic stress (primarily studied in the simulated growth conditions) and their PSMs (including pharmacological activities) from PubMed, Scopus, MEDLINE Ovid, Google Scholar, Databases, and journal websites. We used search keywords: “stress-affected plants,” “plant secondary metabolites, “abiotic stress,” “climatic influence,” “pharmacological activities,” “bioactive compounds,” “drug discovery,” and “medicinal plants” and retrieved published literature between 1973 to 2021. This review provides an overview of variation in bioactive phytochemical production in plants under various abiotic stress and their potential in the biodiscovery of therapeutic drugs. We excluded studies on the effects of biotic stress on PSMs.

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Plant Secondary Metabolites Produced in Response to Abiotic Stresses Has Potential Application in Pharmaceutical Product Development

Studies in family planning

Thunderstorms and the lightning that they produce are inherently interesting phenomena that have intrigued scientists and mankind in general for many years. The study of thunderstorms has rapidly advanced during the past century and many efforts have been made towards understanding lightning, thunderstorms and their consequences. Recent observations of optical phenomena above an active lightning discharge along with the availability of modern technology both for data collection and data analysis have renewed interest in the field of thunderstorms and their consequences in the biosphere. In this paper, we review the electrification processes of a thunderstorm, lightning processes and their association with global electric circuit and climate. The upward lightning discharge can cause sprites, elves, jets, etc. which are together called transient luminous events. Their morphological features and effects in the mesosphere are reviewed. The wide spectrum of electromagnetic waves generated during lightning discharges couple the lower atmosphere with the ionosphere/magnetosphere. Hence various features of these waves from ULF to VHF are reviewed with reference to recent results and their consequences are also briefly discussed.

Thunderstorms, lightning, sprites and magnetospheric whistler-mode radio waves

Characteristics of nighttime VLF/ELF emissions are examined on the basis of the data obtained at our low latitude ground station Jammu (geomagnetic latitude, 22°26′ N; L = 1.17), India during our VLF/ELF campaign. From the detailed analysis of a huge amount of acquired VLF/ELF data at Jammu we have found three remarkable events which clearly exhibit a rise in their frequency in pre and past midnight sectors during magnetically quiet and substorm periods. Our analysis shows that the frequency drift in VLF/ELF emissions seems to be a rare phenomenon at low latitudes during magnetically quiet and substorm periods in pre and post midnight sectors. This property of temporal frequency drift (regular frequency increases with time) in VLF/ELF emissions observed at our station Jammu are interpreted in terms of a quasi-linear electron cyclotron instability model for wave excitation. The initial frequency increase is believed to be due to a combind effect of L-shell drift of energetic electrons. Further, the frequency drifts in VLF/ELF emissions observed at Jammu have been used to estimate the large scale electric field during quiet and substorm periods in pre and post midnight sectors. This investigation would be most useful for the study of the wave-particle interaction processes, magnetospheric plasma structure and particle dynamics, especially during quiet periods in premidnight sector at low latitudes.

Characteristics of nighttime VLF/ELF emissions with frequency drift and estimation of the large-scale electric field from the frequency drift observed at a low latitude Indian ground station, Jammu

Climate change is one of the most severe threats to biodiversity as well as to ecosystem functioning. In this context, the influence of climate change also influences the important secondary metabolites of pharmaceutical plants. Elevated levels of CO 2 , ozone, drought, and cold conditions are major abiotic factors responsible for changing climatic conditions and factors that directly or indirectly influence the growth, production, and synthesis of plant secondary metabolites. The secondary metabolites of medicinal plants are currently used as a safe choice compared to the side effects and multidrug resistance conditions of allopathic treatment. Herbal plants and their products have been broadly used in the treatment of common diseases, like diabetes, cancer, cholera, diarrhea, asthma, pyrexia, since ancient times. Several plants and their secondary metabolites have been recognized to elicit beneficial effects on virulent factors of diseases in vivo and in vitro. Plants are extremely sensitive to climatic changes and do not acclimatize randomly. Some climatic factors enhance secondary metabolites, whereas other abiotic factors decrease the growth of plants to a certain extent. In the current chapter the effects of changing climatic conditions on medicinally important secondary metabolites of plants are summarized.

Medicinal Plants Under Climate Change: Impacts on Pharmaceutical Properties of Plants

This paper reports quasi-periodic pulsing hiss emissions recorded during daytime in the frequency range of 50 Hz–15 kHz at low latitude station Jammu (geomag. lat. = 22 ◦ 26 � N; L =1 .17). It is noted that pulsing VLF emissions are a rare phenomena at low latitudes. The various spectrograms of pulsing VLF hiss emissions presented in this paper clearly show band limited spectrums regularly pulsing with almost equal period of the order of few seconds in the frequency range of ∼ 3–8 kHz. Generation and propagation mechanism of these emissions are briefly discussed.

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Quasi-periodic VLF emissions observed during daytime at a low latitude Indian ground station Jammu

The pattern of age at marriage is undergoing some discernible changes throughout the world. It has a major role in determining the growth rate of the population through its linkage to marital fertility. That is why research on age at marriage has its huge significance, especially in developing countries. Using NFHS III data, we have analyzed the data through Cox Proportional Hazard Model to key out the determinants of female age at marriage among EAG states of India. We have observed that the women who are brought up in the countryside or in towns have more chance to marry earlier than the women belonging to the urban areas. A negative relationship between educational attainment and prevalence of early marriage was also observed. As an outcome of the study, wealth index is found as an important factor that influences the age at marriage.

Female Age at Marriage and Associated Factors in EAG States of India

Whistler data recorded during 5-h period at our low latitude ground station Srinagar (geomag. lat. 24°10′N; L = 1.28) are used to determine lifetime of whistler ducts. On certain occasions, whistler occurrence rate at Srinagar is found to exhibit some periodicity. Power spectrum analysis of occurrence rate yields a dominant period of about 1 hour. It is suggested that this period is an indication of the duct-lifetimes at low L-values. Dispersion analysis of these whistlers has qualitatively confirmed the existence of separate ducts during the period of observation. Further the dispersion analysis shows that these whistlers have propagated in the magnetosphere along higher L-values (L = 2.10–4.12). Power spectrum analysis may not be applicable to the whistler data corresponding to high L-values because at high latitudes the occurrence rate of whistlers is very high. Moreover a large number of ducts might simultaneously contribute to the occurrence rate.

K. K. Singh

Papers

Characteristics of nighttime VLF/ELF emissions with frequency drift and estimation of the large-scale electric field from the frequency drift observed at a low latitude Indian ground station, Jammu

Medicinal Plants Under Climate Change: Impacts on Pharmaceutical Properties of Plants

Quasi-periodic VLF emissions observed during daytime at a low latitude Indian ground station Jammu

Female Age at Marriage and Associated Factors in EAG States of India

Estimation of duct-lifetimes for storm-time low latitude whistlers observed at Srinagar, India