Cirrus clouds provide a significant radiative forcing on the Earth's climate system. This paper looks at the connection in space and time between monthly mean lightning activity observed from the ...Lightning Imaging Sensor on board the International Space Station, and the global monthly mean cirrus cloud cover obtained from the MERRA‐2 reanalysis product. The correlation coefficient between the global monthly mean cloud optical thickness of the cirrus clouds (clouds at altitudes above the 400 hPa pressure levels) with the monthly mean lightning flash counts is 0.84, implying that monthly mean lightning can explain 70% of monthly variability of the global high cloud optical thickness. In addition, lightning amount explains nearly 60% of the monthly mean global area coverage of cirrus clouds. Given these statistically significant connections between lightning and cirrus clouds, we propose using global lightning data as an additional tool for monitoring monthly variability of cirrus clouds.
Plain Language Summary
Cirrus clouds are one of the most important components maintaining the Earth's radiation budget. They reflect shortwave radiation from the Sun while absorbing the longwave radiation from the Earth. The net cloud radiative forcing for cirrus clouds results a warming of the climate. More/less cirrus clouds result in more/less warming of the planet. The moisture for the formation of cirrus clouds in the upper atmosphere is transported there in large part via deep convective storms, many associated with lightning activity and hence defined as thunderstorms. An increasing in cirrus clouds in a warmer atmosphere will amplify the initial warming. We explored in this study the relationship between global cirrus cloud coverage and global lightning activity. The results of the research show that 60%–70% of the monthly variability in global cirrus clouds can be explained by mean global lightning activity.
Key Points
Cirrus clouds are one of the essential components in the atmosphere, with many important feedbacks on the radiation balance of Earth
Monthly mean lightning can explain 70% of the monthly variability of the global high cloud optical thickness
Lightning explains nearly 60% of the monthly mean global area coverage of cirrus clouds
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Translation control of proinflammatory genes has a crucial role in regulating the inflammatory response and preventing chronic inflammation, including a transition to cancer. The proinflammatory ...tumor suppressor protein programmed cell death 4 (PDCD4) is important for maintaining the balance between inflammation and tumorigenesis. PDCD4 messenger RNA translation is inhibited by the oncogenic microRNA, miR-21. AU-rich element-binding protein HuR was found to interact with the PDCD4 3'-untranslated region (UTR) and prevent miR-21-mediated repression of PDCD4 translation. Cells stably expressing miR-21 showed higher proliferation and reduced apoptosis, which was reversed by HuR expression. Inflammatory stimulus caused nuclear-cytoplasmic relocalization of HuR, reversing the translation repression of PDCD4. Unprecedentedly, HuR was also found to bind to miR-21 directly, preventing its interaction with the PDCD4 3'-UTR, thereby preventing the translation repression of PDCD4. This suggests that HuR might act as a 'miRNA sponge' to regulate miRNA-mediated translation regulation under conditions of stress-induced nuclear-cytoplasmic translocation of HuR, which would allow fine-tuned gene expression in complex regulatory environments.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract Previous studies have demonstrated the need for accurate reduction of ankle syndesmosis. Measurement of syndesmosis is difficult on plain radiographs. A computed tomography (CT) scan allows ...better visualisation of the transverse relationship between the fibula and incisura fibularis . The difference (‘G’ a term we coined for ease of description) between the fibula and the anterior and posterior facets of the incisura fibularis was compared between normal and injured ankles following syndesmotic fixation in 19 patients. The mean diastasis (MD) was also calculated, representing the average measurement between the fibula and the anterior and posterior incisura. When compared with the normal side, eight out of 19 (42%) cases were found to have a residual diastasis even after fixation across the syndesmosis. However, if a standard value of G (2 mm) was used for the injured leg only, all of the 19 cases would have abnormal values of ‘G’ following reduction. Our study has clearly demonstrated the need for individualising the assessment method to guide surgeons and radiologists prior to revision surgery. A standard value of ‘G’ of 2 mm as the normal limit cannot be applied universally, as apparent from the data presented in this study.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Oceanic lightning can be a sensitive indicator of aerosol effects on lightning characteristics as thermodynamic contrast is indistinct over adjacent oceanic regions. The study presents discernable ...aerosol impacts on lightning characteristics by analyzing 2 years (2017–2018) of intracloud (IC) and cloud‐to‐ground (CG) lightning data from Earth Networks Total Lightning Network over two key regions in southern South China Sea. Mean stroke density, IC/CG ratio, +IC fraction, and +CG fraction in polluted conditions are respectively 3.7, 2, 1.2, and 5.8‐fold larger than unpolluted counterparts. Total stroke contrast is further confirmed with the GLD360 network. Thermodynamic parameters conversely support slightly stronger convection over clean ocean. Clear evidence shows cloud droplet size diminishes with added aerosol. Aerosol invigorates more frequent and robust mixed‐phase development, endowing maritime convection with continental characteristics. Modifications in the charge reversal temperature and lower and upper positive charge regions are speculated on as means for stimulating more positive ICs and CGs.
Plain Language Summary
Over adjacent oceanic regions, the thermodynamic contrast is indistinct, and this makes oceanic lightning a sensitive indicator of aerosol effects. The southern South China Sea, surrounded by wideband electric‐field sensors in Earth Networks Total Lightning Network, is focused on the response of both intracloud (IC) and cloud‐to‐ground (CG) strokes to added aerosol over 2 years (2017–2018). The thermodynamic and cloud microphysical parameters are quantitatively analyzed between polluted and clean oceanic regions. Distribution maps of sulfur dioxide and aerosol optical depth show clear locations for polluted regions. Mean stroke density, IC/CG ratio, +IC fraction, and +CG fraction in polluted conditions are respectively 3.7, 2, 1.2, and 5.8‐fold larger than the unpolluted counterparts, while thermodynamic parameters conversely support slightly weaker convection over polluted regions and discount its effects in supporting lightning enhancement. Added aerosol decreases cloud effective particle radius of ice and liquid water based on satellite measurement. Larger lower and upper positive charge reservoirs invigorated by the energized graupel‐ice crystal electrification process and possible modification of the charge reversal temperature are speculated as mechanisms to promote more positive strokes. More frequent and robust mixed‐phase development favorable for lightning is stimulated by added aerosol over ocean, endowing maritime convection with continental characteristics.
Key Points
Oceanic lightning can be a sensitive indicator of aerosol effects on lightning characteristics as the thermodynamic contrast is indistinct or even supports weaker convection in the polluted region
Mean stroke density, IC/CG ratio, +IC fraction, and +CG fraction in the polluted oceanic region are respectively 3.7, 2, 1.2, and 5.8 ‐fold larger than the adjacent unpolluted oceanic counterparts
Aerosol provides for more frequent and robust mixed‐phase development, endowing maritime convection with continental characteristics
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Infinite series can converge in various ways to give the resultant function. Particularly, here, we consider the Fourier series and compare it with its Taylor equivalent both of which are convergent ...infinite series in their own rights. However, these are valid under separate limiting conditions. We consider what happens if we try to derive one series from the other or see if such a derivation is possible at all and its implications. An expansion of the Dirichlet kernel, while using a form of the Dirac delta function has been shown to yield the Taylor series in its form. However, it introduced certain restrictions on both the local and global nature of such a function.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The kinetics of cultivation of zygomycete filamentous fungus Rhizopus oryzae in deproteinized whey medium in relation to chitosan production was studied here to optimize chitosan production from R. ...oryzae as well as utilize whey, a by‐product of sweetmeat industry as a cheap source of sugar in the cultivation process. Chitosan content of R. oryzae biomass was found to be increased with time during cultivation and reached maximum (13·6%) after 72 h and then declined steadily. Maximum 1·13 g of chitosan was obtained from one litre of deproteinized whey medium. Concentration of lactose in the medium was observed to be reduced from 45·0 to 11·7 g l⁻¹ during cultivation resulting in decrease in biochemical oxygen demand (BOD) of whey by approx. 60%, and this was important from environmental point of view before discharging whey into any water body. However, no significant change in pH or titratable acidity was noted during the entire course of cultivation, probably due to good buffering capacity of the medium. Molecular weight of chitosan varied from 130 to 230 kDa depending on the time of cultivation, but no significant change in degree of deacetylation of chitosan (approx. 87%) was found during cultivation. SIGNIFICANCE AND IMPACT OF THE STUDY: Whey is the largest by‐product of dairy industries, and its disposal is a big environmental issue because of its high biological oxygen demand (BOD) value. This study will help to lower BOD value of whey by using it as a cultivation medium for fungus R. oryzae that contains chitosan, a very commercially important material on its cell wall. Moreover, the study on biochemical changes in whey during cultivation process with R. oryzae will help to understand the exact changes occurring in the medium and optimize cultivation process to isolate chitosan in larger extent with better and uniform physicochemical properties.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
An inversion algorithm for multistation Schumann resonance measurements is presented and tested in this paper. The location and intensity of the lightning activity is estimated in absolute unit (C2 ...km2/s) from the Schumann resonance electromagnetic field components measured at distant observation sites on the globe. We summarize the main steps of the forward modeling for single and multiple sources and describe the main characteristics of the applied inversion. The applicability of the inversion algorithm is tested via synthetic data.
Key Points
An inversion algorithm for multistation Schumann resonance (SR) measurements is presented and tested via synthetic data
The aim of the model is to determine the distribution and intensity of the global lightning activity in absolute units (C2 km2/s)
Forward modeling for single and multiple sources and the applied inversion method is described in detail
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
•Composite polymer gel electrolytes based on PMMA and SiO2 nanofibers complexed with Li salt are prepared and characterized.•Modifications induced by nanofibers in PMMA lead to excellent conductive ...properties of the membranes.•Nanofibers also significantly improve the mechanical and electrochemical properties of the electrolyte membranes.•Experimental results have been supported by computational modeling.
Display omitted
In this article, a significant study on ionic conduction properties of novel nanocomposite polymer gel electrolytes (NCPGEs) is carried out using poly (methyl methacrylate) (PMMA) with nanofibers of silica (SiO2) complexed with lithium perchlorate (LiClO4) by combining experimental work and computational modelling. The compositional variation of SiO2 nanofibers in polymer electrolytes induces a visible alteration in different characteristics like ionic conductivity, electrochemical stability, interfacial stability, surface morphology and optical properties. Among all the compositions, NCPGEs containing 5 wt% nanofibers exhibit maximum ionic conductivity of 4.6 × 10−3 Scm−1 at room temperature. Fourier Transform Infrared Spectroscopy (FTIR) has shown a better interaction between lithium ions (Li+) with carbonyl group of PMMA in presence of SiO2 nanofibers. X-ray photoelectron spectroscopy (XPS) has confirmed various interactions among different constituents in NCPGEs. A combined molecular dynamics (MD) simulation and density functional theory (DFT) show a stable interaction between polymer with nanofiber filler and Li salt.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The San Joaquin Valley (SJV) experiences some of the worst ozone air quality in the US, frequently exceeding the California 8 h standard of 70.4 ppb. To improve our understanding of trends in the ...number of ozone violations in the SJV, we analyze observed relationships between organic reactivity, nitrogen oxides (NOx), and daily maximum temperature in the southern SJV using measurements made as part of California at the Nexus of Air Quality and Climate Change in 2010 (CalNex-SJV). We find the daytime speciated organic reactivity with respect to OH during CalNex-SJV has a temperature-independent portion with molecules typically associated with motor vehicles being the major component. At high temperatures, characteristic of days with high ozone, the largest portion of the total organic reactivity increases exponentially with temperature and is dominated by small, oxygenated organics and molecules that are unidentified. We use this simple temperature classification to consider changes in organic emissions over the last and next decade. With the CalNex-SJV observations as constraints, we examine the sensitivity of ozone production (PO3) to future NOx and organic reactivity controls. We find that PO3 is NOx-limited at all temperatures on weekends and on weekdays when daily maximum temperatures are greater than 29 °C. As a consequence, NOx reductions are the most effective control option for reducing the frequency of future ozone violations in the southern SJV.
PDF
