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In flowering plants, the tapetum degeneration in post-meiotic anther occurs through developmental programmed cell death (dPCD), which is one of the most critical and sensitive steps for the proper development of male gametophytes and fertility. Yet the pathways of dPCD, its regulation, and its interaction with autophagy remain elusive. Here, we report that high-level expression of Arabidopsis autophagy-related gene BECLIN1 (BECN1 or AtATG6) in the tobacco tapetum prior to their dPCD resulted in developmental defects. BECN1 induces severe autophagy and multiple cytoplasm-to-vacuole pathways, which alters tapetal cell reactive oxygen species (ROS)-homeostasis that represses the tapetal dPCD. The transcriptome analysis reveals that BECN1- expression caused major changes in the pathway, resulting in altered cellular homeostasis in the tapetal cell. Moreover, BECN1-mediated autophagy reprograms the execution of tapetal PCD by altering the expression of the key developmental PCD marker genes: SCPL48 , CEP1 , DMP4 , BFN1 , MC9 , EXI1, and Bcl-2 member BAG5 , and BAG6. This study demonstrates that BECN1-mediated autophagy is inhibitory to the dPCD of the tapetum, but the severity of autophagy leads to autophagic death in the later stages. The delayed and altered mode of tapetal degeneration resulted in male sterility. • Arabidopsis BECN1 overexpression in post-meiotic tobacco tapetum affects its development. • BECN1 triggers severe autophagy and disrupts tapetal cell ROS homeostasis. • BECN1-induced autophagy reprograms the execution of tapetal PCD and inhibits it. • Transcriptome analysis showed altered gross cellular homeostasis in tapetal cells due to BECN1. • Delayed and altered mode of tapetal degeneration ultimately leads to male sterility. [ABSTRACT FROM AUTHOR]

• Autophagy is a conserved process regulating development and stress responses. • Genome-wide AuTophaGy-related genes (ATG) identified in 4 Gossypium species. • A total of 40 GhirATG, 33 GaATG, 34 GherbATG, and 25 GrATG genes were identified. • The ATG8 subclass genes were significantly expressed under stress conditions. • qRT-PCR of selected 12 GhirATGs in leaves treated with stress elicitors showed high expression. Autophagy is an evolutionarily conserved process mediated by AuTophaGy (ATG) genes, in which cellular components are degraded and recycled within vacuoles or lysosome. Yeast ATG was extensively studied; their homologs are reported in plants including Arabidopsis. However, they have not been reported in cotton. In the present study, the ATG cascade genes were studied in four Gossypium species, namely G. hirsutum, G. arboreum, G. herbaceum, and G. raimondii. A total of 40 GhirATG , 33 GaATG , 34 GherbATG , and 25 GrATG genes were identified in these species. These ATG sequences exhibited conserved ATG domains and other overlapping domains, including Ras, Pkinase, Snf7, WD40, Glyco_hydro_17, and bZIP_1, and were named based on their phylogenetic relationships with Arabidopsis ATGs. A phylogenetic analysis revealed evolutionary relationships among ATG genes among these species, as well as significant sub-clades indicating patterns of gene retention. Based on synonymous and non-synonymous substitutions, cotton groups diverged at different times from Arabidopsis. Gene structure analysis and chromosome localization showed exon-intron patterns and locations. Expression analysis of ATGs in different tissues during development and under stress conditions indicated their functional specificity. The ATG8 subclass genes were significantly expressed under abiotic stress conditions, indicating their role in stress response. In addition, qRT-PCR analysis of selected 12 GhirATGs in leaves treated with stress elicitors, MeJA, SA, NaCl, and PEG for varying time intervals showed a pattern of their significant upregulation. The findings contribute to our understanding of autophagy-related processes in cotton, including their potential role in stress response and development. [ABSTRACT FROM AUTHOR]

Abstract: In this Letter we report the effect of two different cathode structures – tubular and squirrel cage, on neutron output from a miniature plasma focus device. The squirrel cage cathode is typical of most DPF sources, with an outer, tubular envelope that serves as a vacuum housing, but does not carry current. The tubular cathode carries the return current and also serves as the vacuum envelope, thereby minimizing the size of the DPF head. The maximum average neutron yield of for the tubular cathode at 4 mbar was enhanced to with squirrel cage cathode at 6 mbar operation. These results are explained on the basis of a current sheath loading/mass choking effect. The penalty for using a non-transparent cathode negates the advantage of the smaller size of the DPF head. [Copyright &y& Elsevier]

Titanium thin film was prepared on copper substrate by thermal evaporation method. Gettering property of titanium film for deuterium was studied for different values of temperature, pressure and time. The studies were carried out in an ultra high vacuum system. The substrate was mounted in the vacuum system on a heater whose temperature was controlled by PID controller. The titanium thin film was activated for 1 h at a temperature of 500 °C under vacuum. After activation, during cool down, the vacuum chamber was pressurized at various pressure values of deuterium and left for absorption for various time periods. Comparative studies of the amount of deuterium desorption for various charging pressure and exposure time were studied with the help of residual gas analyzer. Attempts were made to qualify the process of deuteration of the titanium film. The results of these studies are presented in this article. • Comparative study of deuteriated titanium thin film performed by RGA. • RGA spectrum reveals about surface limited and diffusion limited desorption. • Effect of charging pressure & duration on bulk concentration of deuterium studied. • Achievement of higher bulk concentration could be established through this study. [ABSTRACT FROM AUTHOR]

Abstract: An optical fiber, partially stripped of its cladding is shown to sense refractive index of a liquid in which the uncladded sensing region is immersed, to a high degree of precision and over a wide range of refractive index. The slope of sensor response is found to be non linear, can have either sign and can change sign at around refractive index of the fiber. The sensitivity of the sensor to refractive index change is dependent on cladding thickness and is a maximum at an intermediate thickness value. It is insensitive to the presence of absorption at the wavelength at which refractive index is being measured and to the chemical nature of the solute. Experiments designed to show that cladding modes are responsible for sensing are described. [Copyright &y& Elsevier]

Zirconium based alloys are proved to be a good material for hydrogen storage as well as a vacuum pump. A non evaporable getter pump based on St 172 was tested for deuterium storage capacity in a sealed off vacuum device. The vacuum in the range of ultra high vacuum was maintained by the getter pump by gettering. Initial vacuum was created by a turbo molecular pumping system. After activation of the getter, test chamber was charged at 1 bar and 3 bar deuterium pressure for 24 h in two different experimental campaigns. After charging with deuterium, the chamber was pumped to ultimate vacuum and isolated from the TMP. The partial pressure of deuterium for different temperature of the getter was measured in sealed condition. Higher charging pressure improves the partial pressure of deuterium during desorption cycle. The experimental details and the results are presented in this article. • St 172 NEG was tested for use as deuterium source in sealed off vacuum device. • Higher charging of deuterium is effective to get higher operational pressure. • Higher charging helps for low temperature operation for specific deuterium pressure. [ABSTRACT FROM AUTHOR]