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Nationalism calls for one’s loyalty and affiliation towards their chosen nation. Various versions of nationalism emphasise that one must prioritise said nation above themselves and their personal ethics, hence, allowing the nation to overpower the nationalist’s individuality. In this article, we use Critical Discourse Analysis to deconstruct the narratives of nationalism as portrayed in two popular films, viz. The Kashmir Files and Uri: The Surgical Strike, which are based on real historical events – the exodus of Kashmiri Hindus and the surgical strike by the Indian Army in retaliation to the Uri attack. Both films use narrative strategies to frame key historical events into certain ideological contexts, and hence they serve the populist purpose of swaying viewers’ opinion in favour of the dominant socio-political class. [ABSTRACT FROM AUTHOR]

This study reports thunderstorm-generated acoustic and gravity waves from a tropical location using newly launched Indian navigation system NavIC for the first time. The detection of acoustic wave components in travelling ionospheric disturbance (TID) measurement is very significant. In compared to acoustic wave gravity wave signature is more ubiquitous because gravity wave propagates in thermospheric altitude by dissipative filtering process. The turbulent nature in plasma characteristics due to strong vertical drift and plasma motion in lower latitude region generate strong scintillation effect and plasma bubble. Large temperature gradient at thermospheric altitude also provides a strong attenuation effect in this region for comparatively high frequency acoustic wave. We have found the TID signatures on TEC variation for acoustic wave up to 0.4 TECU for both the days whereas gravity wave induced signatures went up to 0.8 TECU. Measurements using GPS signal validate signatures obtained from the NavIC signal. The study shows the potential of application of NavIC system for middle atmosphere as well as thermospheric study and understanding of coupling process between various atmospheric layers in tropical region which is not well known so far. [ABSTRACT FROM AUTHOR]

Coronal mass ejections (CMEs) that cause geomagnetic disturbances on the Earth can be found in conjunction with flares, filament eruptions, or independently. Though flares and CMEs are understood as triggered by the common physical process of magnetic reconnection, the degree of association is challenging to predict. From the vector magnetic field data captured by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO), active regions are identified and tracked in what is known as Space Weather HMI Active Region Patches (SHARPs). Eighteen magnetic field features are derived from the SHARP data and fed as input for the machine-learning models to classify whether a flare will be accompanied by a CME (positive class) or not (negative class). Since the frequency of flare accompanied by CME occurrence is less than flare alone events, to address the class imbalance, we have explored the approaches such as undersampling the majority class, oversampling the minority class, and synthetic minority oversampling technique (SMOTE) on the training data. We compare the performance of eight machine-learning models, among which the Support Vector Machine (SVM) and Linear Discriminant Analysis (LDA) model perform best with True Skill Score (TSS) around 0.78 ± 0.09 and 0.8 ± 0.05, respectively. To improve the predictions, we attempt to incorporate the temporal information as an additional input parameter, resulting in LDA achieving an improved TSS of 0.92 ± 0.04. We utilize the wrapper technique and permutation-based model interpretation methods to study the significant SHARP parameters responsible for the predictions made by SVM and LDA models. This study will help develop a real-time prediction of CME events and better understand the underlying physical processes behind the occurrence. [ABSTRACT FROM AUTHOR]

Climatic changes and the recent surge in weather extremities are alarming concerns for society today. Tropical squall events with extremely heavy rainfall and lightning are among the very severe ones among such activities. Usually, squalls have a leading convective edge followed by a stratiform trail; however, the reverse is also observed in rare cases. This work presented a thorough study on a conventional and an unconventional squall with nearly similar severities from a tropical location, Kolkata. The study reports notably high wind gusts and lightning activities during both events, with the latter one showing higher values. The CAPE increase and OLR drops were significant in both the cases. Breakage of storm front were noticed in the first squall, which possibly resulted in higher CAPE surrounding the study location even though the localised value was slightly larger during the second event. The unconventional squall having a shorter life cycle showed weaker vertical wind shear. The cloud system during the second squall structure showed dominance of smaller cloud particles and lower cloud top pressure than the first event, whereas the cloud mask fraction and cloud water path were large in this case. The rain microphysics has been studied for the two said events and a greater number of drops has been observed in the reflectivity through region than in the stratiform phase for the squall with trailing convective line, unlike the one with conventional structure. The rain microphysical properties showed clearly distinguishable behaviour during the three phases of the squall passage for both the events. Exceptionally high a values in empirical relation between Z and R were noticed in both the cases. The study reports higher path attenuation during the first event. The study can be useful in improving the understanding of the efficiency of different atmospheric and precipitation microphysical features in the predictability of a mesoscale system. Research highlights: The current work has presented a thorough analysis of two tropical squalls with different organisational modes. The variation in associated weather variables has been studied for the two events. A thorough study of precipitation microphysics has been carried out for the two squalls. The conventional factors used for prediction of mesoscale systems were analysed in detail for these cases to understand the efficiency of these elements in prediction of an unconventional convective system like a squall with a leading stratiform edge studied here. [ABSTRACT FROM AUTHOR]

• The 3D grain microstructure of a twinned nickel-tungsten alloy nano polycrystalline tip has been reconstructed using electron diffraction signals. • The five-parameter grain boundary characteristic of the interfaces were derived from the scanning precession electron diffraction dataset. • An automated post-processing step identifies and deselects reflections common to overlapping crystals to improve the reconstruction of their virtual dark-field images. • A 3D Hough transform is proposed to determine the orientation of planar interfaces. Determining the full five-parameter grain boundary characteristics from experiments is essential for understanding grain boundaries impact on material properties, improving related models, and designing advanced alloys. However, achieving this is generally challenging, in particular at nanoscale, due to their 3D nature. In our study, we successfully determined the grain boundary characteristics of an annealed nickel-tungsten alloy (NiW) nanocrystalline needle-shaped specimen (tip) containing twins using Scanning Precession Electron Diffraction (SPED) Tomography. The presence of annealing twins in this face-centered cubic (fcc) material gives rise to common reflections in the SPED diffraction patterns, which challenges the reconstruction of orientation-specific virtual dark field (VDF) images required for tomographic reconstruction of the 3D grain shapes. To address this, an automated post-processing step identifies and deselects these shared reflections prior to the reconstruction of the VDF images. Combined with appropriate intensity normalization and projection alignment procedures, this approach enables high-fidelity 3D reconstruction of the individual grains contained in the needle-shaped sample volume. To probe the accuracy of the resulting boundary characteristics, the twin boundary surface normal directions were extracted from the 3D voxelated grain boundary map using a 3D Hough transform. For the sub-set of coherent Σ3 boundaries, the expected {111} grain boundary plane normals were obtained with an angular error of <3° for boundary sizes down to 400 nm². This work advances our ability to precisely characterize and understand the complex grain boundaries that govern material properties. [ABSTRACT FROM AUTHOR]

The effect of climate change on precipitation pattern is emerging out as a serious global challenge. However, the quantification and assessment of the climate change effect on precipitation are a challenging issue given the spatio-temporal inhomogeneity of rainfall. Previous studies mostly used only rain intensity information for the identification of climate change signature by selecting homogeneous rain regions. Rain climatology, however, has several other important characteristics like occurrence of multiple rain type, occurrence of extreme rain events and their spatial distribution. The present study provides a novel approach to combine satellite data with ground measurements for addressing this issue. In this study, the Indian subcontinent has been divided into homogeneous regions based on six different rain features, obtained from ground observations and TRMM satellite measurements of 12 years, using K-medoid clustering technique. The rain features showed distinguishable patterns in the resulting nine homogeneous rain zones and distinct behavioural patterns in the inter-relationships between the various rain features. To verify the consistency of the proposed regionalization, the recent changes in mean monsoon rain rates are then studied using 40 years of rain gauge measurements for these regions. Increasing trends in monsoon rain are observed in two homogeneous regions whereas five of them have shown decreasing signature of rain intensity. Although the present study focused only on monsoon rain over India, the results indicate the suitability of the proposed method as an efficient technique of identifying homogeneous region for other seasons and locations as well. [ABSTRACT FROM AUTHOR]

This article implements a Convolutional Neural Network (CNN)-based deep-learning model for solar-wind prediction. Images from the Atmospheric Imaging Assembly (AIA) at 193 Å wavelength are used for training. Solar-wind speed is taken from the Advanced Composition Explorer (ACE) located at the Lagrangian L1 point. The proposed CNN architecture is designed from scratch for training with four years' data. The solar-wind has been ballistically traced back to the Sun assuming a constant speed during propagation, to obtain the corresponding coronal-intensity data from AIA images. This forecasting scheme can predict the solar-wind speed well with a RMSE of 76.3 ± 1.87 km s−1 and an overall correlation coefficient of 0.57 ± 0.02 for the year 2018, while significantly outperforming benchmark models. The threat score for the model is around 0.46 in identifying the HSEs with zero false alarms. [ABSTRACT FROM AUTHOR]

Objectives: "Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016" provides guidelines in regard to prompt management and resuscitation of sepsis or septic shock. The study is aimed to assess the robustness of randomized controlled trials (RCTs) that formulate these guidelines in terms of fragility index and reverse fragility index. Method: RCTs that contributed to these guidelines having parallel two-group design, 1:1 allocation ratio, and at least one dichotomous outcome were included in the study. The median fragility index was calculated for RCTs with significant statistical outcomes, whereas the median reverse fragility index was calculated for RCTs with nonsignificant statistical results. Results: Hundred RCTs that met the inclusion criteria were analyzed. The median fragility index was 5.5 [95% confidence interval (CI) 1--30] and median reverse fragility index was 13 (95% CI 12.07--16.8) at a p value of 0.05. The median reverse fragility index was 16 (95% CI 10--26) at a p value of 0.01. Most of the RCTs included in this analysis were of good quality, having a median Jadad score of 6. Conclusion: This analysis found that the surviving sepsis guidelines were based on highly robust RCTs with statistically insignificant results and on some moderately robust RCTs with statistically significant results. RCTs with statistically insignificant results were more robust than RCTs with statistically significant results in regard to these guidelines. [ABSTRACT FROM AUTHOR]

Collisional drop breakup is one of the important processes during evolution of the rain drops and leads to modified shape of the drop size distribution (DSD), which is a primary parameter in rain retrieval in remote sensing techniques. Though several experimental and observational studies have been performed in the recent past on this aspect, the impact of the same in natural rain, particularly in orographic rain, is still poorly represented. The present study aims to examine and identify the rain conditions in which collisional drop breakup is prominent and is capable of modifying the shape of DSD in orographic rain over north-eastern India. The 2-min averaged DSDs from four hilly locations are studied in both stratiform and convective rain types separately using ground-based DSD measurements. Even though drop breakup in intense to moderate rain seemed to be in notable percentage (0.2% - 11.2%), the low intensity rain also showed a considerable break-up signature (2.5% - 9%), depending upon the locations. The overall results showed that collisional breakup was more prominent in convective rain (1%–11%) than in stratiform rain (4%–5%), however, breakup is also seen primarily during stratiform rain in two of the locations. The Z -R coefficients are found to be significantly different for the break-up and non-break up cases. For breakup cases, both convective and stratiform rainfall shows an increase in intercept parameter for all locations. For stratiform rain types, the coefficient a and b ranged from 307.6 to 321.4 (167.1–178.7) and 1.27–1.37 (1.31–1.34) for rain with break-up (without break-up), respectively. In the case of convective rain, the coefficients were found to be in the range of 377.5–654.7 (270.4–641.3) and 1.28–1.42 (1.14–1.31) with break-up (without break-up), respectively. The results suggest that collisional breakup is an important process in orographic rain over North-Eastern India and it has to be taken care of, while studying rainfall over these regions, particularly in conventional radar derived quantitative precipitation estimates (QPE). [Display omitted] • Collisional drop breakup in orographic rain has been explored in four tropical Indian locations. • Breakup occurs mainly in convective rain at two locations, while the other two show notable breakup in stratiform rain. • Occurrence of equilibrium DSD registered highest in low rain intensity for all locations. • The Z -R coefficient "A" was consistently higher across all locations and rain types in situations involving collisional drop breakup in comparison to scenarios with no breakup. [ABSTRACT FROM AUTHOR]

Purpose: The present study systematically searched important medical databases, assessed the quality of available pieces of evidence, and performed a meta-analysis to test the efficacy of different therapeutic options currently available for treating COVID-19. Materials and methods: PubMed, CNKI, LILACS, Koreamed, WHO clinical trial registry, and medRxiv were searched since December 2019. Any observational or controlled study that tested the efficacy of any pharmacological intervention in COVID-19 patients either prospectively or retrospectively was included in the qualitative analysis. We assessed outcomes as dichotomous variables, i.e., a patient having a positive clinical outcome. Relative risks/risk ratios (RR) having a 95% confidence interval (CI) were derived. Studies conforming to inclusion criteria were pooled using the random-effect model. Results: Nine trials on hydroxychloroquine (HCQ), six studies on antiviral, four studies on monoclonal antibodies, two on corticosteroids, two on convalescent plasma (CP), and one on interferon-α2b were included in the systematic review. Meta-analysis containing six scientific trials and analyzing 522 patients revealed that the relative risk of positive clinical outcomes with HCQ treatment was 1.042 (95% CI, 0.884 to 1.874) with a number needed to treat (NNT) of 12.6. A meta-analysis of two studies analyzing 285 patients showed that the relative risk of clinical resolution with lopinavir and ritonavir combination was 1.152 (95% CI 0.709 to 1.87). Out of various antiviral used, the only remdesivir showed a positive result in a case series. Monoclonal antibodies showed decreased C-reactive protein, decreased oxygen, and ventilator requirements. A corticosteroid may increase mortality with increased dose. Two small case series on CP showed some promising results. Conclusion: The study showed slightly favorable results with HCQ, monoclonal antibodies, remdesivir, and CP in treating COVID-19 patients. Further research is warranted in establishing the efficacy of studied interventions. [ABSTRACT FROM AUTHOR]

• A detail study of rain fade at Ka band over tropical region has been done. • Performance comparison of experimental link at 20/30 GHz with ITU-R model done. • "s" parameter relating fade slope to filter characteristics is calculated. Dynamic characteristics of Ka band rain fade (or rain attenuation) over tropical region are relatively less studied, though they are essential for implementation of suitable fade mitigation techniques. In this paper, dynamic characteristics of rain fade at 20 GHz and 30 GHz from GSAT-14 satellite are reported with experimental measurements at Ahmedabad, India. ITU-R model for fade slope probability distribution has been analyzed in this paper and Ka band rain fade has been investigated based on this fade-slope analysis. The ITU-R model is found to closely match 20 GHz measurements, though differences increase at 30 GHz. Fade slopes are found to be within ±0.5 dB/s at both 20 and 30 GHz. Both positive and negative slopes of the fade slope distributions are quasi-similar. ITU-R model's s parameter, relating fade slope to filter characteristics, is found to be very close to the measured value for this region. Distributions of fade slopes are also found to be dependent on the standard deviation values similar to ITU-R recommendation at 20 GHz, but significant deviation is observed at 30 GHz. This observed frequency dependency might be due to increase in cloud attenuation at high frequencies or may be due to limited data set. Results indicate needs of further experimental data at high frequencies from other tropical regions to gain further insight into the fade slope characteristics. This will ultimately help in designing a better prediction model in future. [ABSTRACT FROM AUTHOR]

• Automated detection of solar coronal holes based on fuzzy dual contour model. • Proposed method can handle topological changes as well the presence of vague boundary. • The method outperform existing models in terms of accuracy and computational time. The presence of coronal holes in solar disk plays an important role in influencing the space weather and generation of the solar wind. As such there lies a requirement in proper study and prediction of coronal holes occurs in the solar disk. This, in turn, arises the necessity of detection of coronal holes present in the solar disk. In this work, a Hough transformed inspired fuzzy-energy simulated dual contours-based segmentation technique has been proposed for the detection and extraction of holes in solar disk. In the proposed method Hough transform has been induced to initialize the contour for the contour-based method of segmentation. In the algorithm, two contours (active and static) have been initiated and made to evolve based on the energy function by incorporating the gray-scale intensity. Here in the work one contour is made to deform its shape while the other contour is kept static for the coronal holes detection purpose. The experiment has been carried out on few benchmark datasets and the corresponding outcomes have been compared with the results of other existing algorithms. The comparison results highlight the performance of the proposed technique in detection of coronal holes in solar disk. [ABSTRACT FROM AUTHOR]

Navigation satellites provide a good opportunity to monitor both ionospheric and tropospheric conditions by using propagation delays in the L-band signal. However, the availability of S-band frequency in the Indian Regional Navigation Satellite System, Navigation with Indian Constellation (NavIC), provides a unique opportunity to utilize signal strength for monitoring thunderstorms. This article, for the first time, demonstrates that NavIC satellite signal strength measurements can be used to detect thunderstorms. A dynamic time warping technique has been used to detect the presence of thunderstorm cloud systems. The method has been tested with several case studies in Kolkata using one-year measurements. The results indicate suitability of such techniques for monitoring and forecasting of thunderstorms using a navigation satellite. [ABSTRACT FROM AUTHOR]

• Detailed oxidation study of W-free low density Co base superalloy is presented. • Oxidation is primarily controlled by outward diffusion of Co and Ni. • S/TEM combined with EDS is applied to understand the oxide phase evolution. • A mechanism has been derived from these studies. The paper reports mechanism of high temperature oxidation of the new γ'-strengthened Co-30Ni-10Al-5Mo-2Ta (at%) alloy. The plots of mass gain vs. time show a parabolic growth behaviour at a temperature range of 650–800 °C. The cross-sections of the oxidised samples reveal formation of a complex multilayer of oxides. The top layer comprises of Co 3 O 4 followed by a solid solution of (Co 1-x ,Ni x)O (x varying from 0-0.2). A middle layer evolves with time comprising hexagonal molybdate Co 2 Mo 3 O 8 , metastable TaO and amorphous Al 2 O 3. The γ' dissolve near the interface exposing the γ solid solution with growth of amorphous Al 2 O 3 along the grain boundary. [ABSTRACT FROM AUTHOR]

Quantitative precipitation estimations (QPE) from remote sensing observations requires understanding of the rain characteristics. Rain drop size distribution (DSD) is the fundamental parameter for characterizing rain and depends strongly on the climate, origin and precipitation type. Past studies are mostly concentrated on the DSD variations on locations and rain type, but only a few studies focused on the rain DSD difference between maritime and continental circulation. The aim of the present study is to analyse the different precipitation properties associated with maritime and continental rain at a coastal Indian location. The rain rate probability, DSD parameters, rain rate( R )-radar reflectivity ( Z ) relation and rain attenuation under different rain conditions are presented here based on three years of DSD measurements at Trivandrum (08°52′, 76°93′). Higher value of mean rain rate is observed for maritime rain than continental rain. The Z-R relation is also found to be significantly different for these two types of rain. Abundance of smaller drops is indicated in maritime rain whereas large raindrops has dominance in continental rain. The rain attenuation associated with maritime rain also found to be notably higher than the continental rain. The coefficients for converting the rain rate to attenuation values for different frequencies are estimated for the present location. The results indicate the scope of improvement in QPE by adjusting the Z-R relation from the characteristics difference in rain microstructure/attenuation for continental and maritime rain. [ABSTRACT FROM AUTHOR]

Automatic nowcasting of convective initiation and thunderstorms has potential applications in several sectors including aviation planning and disaster management. In this paper, random forest based machine learning algorithm is tested for nowcasting of convective rain with a ground based radiometer. Brightness temperatures measured at 14 frequencies (7 frequencies in 22–31 GHz band and 7 frequencies in 51–58 GHz bands) are utilized as the inputs of the model. The lower frequency band is associated to the water vapor absorption whereas the upper frequency band relates to the oxygen absorption and hence, provide information on the temperature and humidity of the atmosphere. Synthetic minority over-sampling technique is used to balance the data set and 10-fold cross validation is used to assess the performance of the model. Results indicate that random forest algorithm with fixed alarm generation time of 30 min and 60 min performs quite well (probability of detection of all types of weather condition ∼90%) with low false alarms. It is, however, also observed that reducing the alarm generation time improves the threat score significantly and also decreases false alarms. The proposed model is found to be very sensitive to the boundary layer instability as indicated by the variable importance measure. The study shows the suitability of a random forest algorithm for nowcasting application utilizing a large number of input parameters from diverse sources and can be utilized in other forecasting problems. [ABSTRACT FROM AUTHOR]

Introduction: Reported incidence of acute cor pulmonale (ACP) in patients with acute respiratory distress syndrome (ARDS) varies from 10% to 84%, despite being subjected to lung protective ventilation according to the current guidelines. The objective of this review is to find pooled cumulative incidence of ACP in patients with ARDS undergoing lung protective ventilation. Materials and Methods: We searched MEDLINE, EMBASE, Cochrane Library, KoreaMed, LILACS, and WHO Clinical Trial Registry. Cross-sectional or cohort studies were included if they reported or provided data that could be used to calculate the incidence proportion of ACP. Inverse variance heterogeneity (IVhet) and random effect model were used for the main outcome and measures. Results: We included 16 studies encompassing 1661 patients. The cumulative incidence of ACP using IVhet analysis was 23% (95% confidence interval [CI] = 18%-28%) over 3 days of lung protective ventilation. Random effect analysis of 7 studies (1250 patients) revealed pooled odd ratio of mortality of 1.16 (95% CI = 0.80-1.67, P = 0.44) due to ACP. Conclusion: Patients with ARDS have a 23% risk of developing ACP with lung protective ventilation. Findings of this review indicate the need of updating existing guidelines for ventilating ARDS patients to incorporate right ventricle protective strategy. PROSPERO registration number: CRD42017054688. [ABSTRACT FROM AUTHOR]

This paper investigates the variability of raindrop size distribution (DSD) and rain integral parameters at Ahmedabad, a tropical location, in relation to the radar estimation of rainfall. Rain DSDs for the years 2006–2007 at Ahmedabad (23°04′N, 72°38′E) have been measured using a disdrometer. Variability of DSD is evaluated for different seasons and its effect on the integral rain parameters like radar reflectivity, rainfall intensity and attenuation are examined. A percentage contribution of different drop diameters on rain integral parameters is studied to understand the seasonal behaviour of rain attenuation and radar reflectivity. It is observed that drops with diameter around 3 mm contribute maximum to the radar reflectivity while drops having a diameter around 2 mm contribute the maximum to the rainfall intensity for the present location. The critical diameter range responsible for the maximum contribution in rain attenuation found to shift towards large drops with an increase in rain rate for a fixed frequency. Linear and non-linear regression analysis between radar reflectivity and rainfall intensity show significant variations in different seasons but does not differ much for different regression techniques. Results point to the necessity of considering the seasonal variability of rain DSD in radar remote sensing and will be helpful for better characterizing of rain parameters from radar measurements. [ABSTRACT FROM AUTHOR]

Despite the need for molecularly smooth self-assembled monolayers (SAMs) on silicon dioxide surfaces (the most common dielectric surface), current techniques are limited to nonideal silane grafting. Here, we show unique bioinspired zwitterionic molecules forming a molecularly smooth and uniformly thin SAM in "water" in >1 min on various dielectric surfaces, which enables a dip-coating process that is essential for organic electronics to become reality. This monomolecular layer leads to high mobility of organic field-effect transistors (OFETs) based on various organic semiconductors and source/drain electrodes. A combination of experimental and computational techniques confirms strong adsorption (Wad < 20 mJ m-2), uniform thickness (∼0.5 or ∼1 nm) and orientation (all catechol head groups facing the oxide surface) of the "monomolecular" layers. This robust (strong adsorption), rapid, and green SAM represents a promising advancement toward the next generation of nanofabrication compared to the current nonuniform and inconsistent polysiloxane-based SAM involving toxic chemicals, long processing time (<10 h), or heat (<80 °C). [ABSTRACT FROM AUTHOR]

Summary Information of vertical rain structure is important for accurate quantitative precipitation estimation from weather radars and space-borne radars. In this paper, some characteristics of the vertical rain structure observed using a Ka band Micro Rain Radar at three tropical locations in India are presented. The average vertical structure is studied in terms of drop size distribution (DSD), fall velocity, rain rate, liquid water content and radar reflectivity profile. The changes in vertical rain structure with rain rate is observed to be significant only above 20 mm/h in Ahmedabad and Trivandrum, although, in Shillong, significant variation is observed starting from 2 mm/h. Results show a significant negative slope of the fall velocity of rain drops and Ka band radar reflectivity up to melting layer height for rain rate above 20 mm/h indicating a shift in the drop size distribution (DSD) toward lower size at all sites. The near ground measurements show strong variation of rain structure for all rain rates. The mean DSD near ground (<1 km) indicates the dominance of smaller drops during rain rates below 2 mm/h, but significant increase in drop size in rain rate above 20 mm/h. The findings suggest using different retrieval techniques for near ground rain estimation than the rest of the height profile as well for high rain rate events. [ABSTRACT FROM AUTHOR]

In the present study, the effectiveness of nowcasting convective activities using a microwave radiometer has been examined for Kolkata (22.65° N, 88.45° E), a tropical location. It has been found that the standard deviation of brightness temperature (BT) at 22 GHz and instability indices like Lifting Index (LI), K Index (KI) and Humidity Index (HI) has shown definite changes before convective events. It is also seen that combination of standard deviation of BT at 22 GHz and LI can be most effective in predicting convection. A nowcasting algorithm is prepared using 18 isolated convective events of 2011 and in all cases, a marked variation of these parameters has been seen an hour before the event. Accordingly, a prediction model is developed and tested on convective events of 2012 and 2013. It is seen that the model gives reasonable success in predicting convective rain about 7075 min in advance with a prediction efficiency of 80%. [ABSTRACT FROM AUTHOR]

Mussel adhesion to mineral surfaces is widely attributed to 3,4-dihydroxyphenylalanine (Dopa) functionalities in the mussel foot proteins (mfps). Several mfps, however, show a broad range (30%-100%) of tyrosine (Tyr) to Dopa conversion suggesting that Dopa is not the only desirable outcome for adhesion. Here, a partial recombinant construct of mussel foot protein-1 (rmfp-1) and short decapeptide dimers with and without Dopa are used and both their cohesive and adhesive properties on mica are assessed using a surface forces apparatus. Our results demonstrate that at low pH, both the unmodified and Dopa-containing rmfp-1s show similar energies for adhesion to mica and self-self-interaction. Cohesion between two Dopa-containing rmfp-1 surfaces can be doubled by Fe3+ chelation, but remains unchanged with unmodified rmfp-1. At the same low pH, the Dopa-modified short decapeptide dimer did not show any change in cohesive interactions even with Fe3+. The results suggest that the most probable intermolecular interactions are those arising from electrostatic (i.e., cation-π) and hydrophobic interactions. It is also shown that Dopa in a peptide sequence does not by itself mediate Fe3+ bridging interactions between peptide films: peptide length is a crucial enabling factor. [ABSTRACT FROM AUTHOR]

A priori estimation of delays with error variance of atmospheric radio wave propagation is important for precise position estimation and integrity of the system like Global Positioning System (GPS). Tropospheric effects are less severe than the ionospheric counterpart, but behave in a complex manner, making it difficult to isolate them. In this present paper, a ground based radiometer has been utilized to study the characteristics of tropospheric delay and compared it with the MODIS satellite observations over Kolkata (22.57°N, 88.37°E). Results indicate a good agreement between radiometer and MODIS data except the monsoon months. A climatology of spatial and temporal variation of dry and wet tropospheric delay over the Indian subcontinent have also been estimated using MODIS data and NCEP–NCAR reanalysis data for 2008–2012. The spatial variations of dry delay over Indian region are observed to be in the range of 120–250 cm with limited seasonal variability. However, the wet delay varies from 20 cm in winter months to 45 cm during monsoon period in the coastal and central Indian region. Further analysis reveals that the contribution of wet delays in total delay is significant only along the Indo-Gangetic plain. This indicates that extra precaution is needed in handling tropospheric delay for this region due to fast varying nature of water vapor. [ABSTRACT FROM AUTHOR]

Numerous attempts have been made to translate mussel adhesion to diverse synthetic platforms. However, the translation remains largely limited to the Dopa (3,4-dihydroxyphenylalanine) or catechol functionality, which continues to raise concerns about Dopa's inherent susceptibility to oxidation. Mussels have evolved adaptations to stabilize Dopa against oxidation. For example, in mussel foot protein 3 slow (mfp-3s, one of two electrophoretically distinct interfacial adhesive proteins in mussel plaques), the high proportion of hydrophobic amino acid residues in the flanking sequence around Dopa increases Dopa's oxidation potential. In this study, copolyampholytes, which combine the catechol functionality with amphiphilic and ionic features of mfp-3s, were synthesized and formulated as coacervates for adhesive deposition on surfaces. The ratio of hydrophilic/hydrophobic as well as cationic/anionic units was varied in order to enhance coacervate formation and wet adhesion properties. Aqueous solutions of two of the four mfp-3s-inspired copolymers showed coacervate-like spherical microdroplets (ϕ ≈ 1-5 μm at pH ∼4 (salt concentration ∼15 mM). The mfp-3s-mimetic copolymer was stable to oxidation, formed coacervates that spread evenly over mica, and strongly bonded to mica surfaces (pull-off strength: ∼17.0 mJ/m²). Increasing pH to 7 after coacervate deposition at pH 4 doubled the bonding strength to ∼32.9 mJ/m² without oxidative cross-linking and is about 9 times higher than native mfp-3s cohesion. This study expands the scope of translating mussel adhesion from simple Dopa-functionalization to mimicking the context of the local environment around Dopa. [ABSTRACT FROM AUTHOR]

The performances of three instruments namely, Joss–Waldvogel disdrometer, laser precipitation monitor and micro rain radar, are assessed in terms of their ability to measure rain related parameters and to better understand the dependency of measured parameters on the working principles of the instruments. Twenty one rain events of year 2013 pertaining to South-West monsoon are considered for this study. The raindrop size distributions measured by the three instruments show good agreement only for medium sized (1–3 mm) raindrops and for medium rain rates (up to 30 mm/h). However, the mutual agreements are not very good in case of large (> 5 mm) and very small raindrops (< 0.5 mm) as well as for very high rain rates (> 30 mm/h) and very high radar reflectivity factor (> 40 dB). The radar reflectivity–rain rate relation is also studied using linear regression method which shows distinct differences for these instruments, indicating the high sensitivity of Z–R relation on the instrumental measuring principle. [ABSTRACT FROM AUTHOR]

Understanding the interactions between collagen and adhesive mussel foot proteins (mfps) can lead to improved medical and dental adhesives, particularly for collagen-rich tissues. Here we investigated interactions between collagen type-1, the most abundant load-bearing animal protein, and mussel foot protein-3 (mfp-3) using a quartz crystal microbalance and surface forces apparatus (SFA). Both hydrophilic and hydrophobic variants of mfp-3 were exploited to probe the nature of the interaction between the protein and collagen. Our chief findings are: 1) mfp-3 is an effective chaperone for tropocollagen adsorption to TiO 2 and mica surfaces; 2) at pH 3, collagen addition between two mfp-3 films ( W c = 5.4 ± 0.2 mJ/m 2 ) increased their cohesion by nearly 35%; 3) oxidation of Dopa in mfp-3 by periodate did not abolish the adhesion between collagen and mfp-3 films, and 4) collagen bridging between both hydrophilic and hydrophobic mfp-3 variant films is equally robust, suggesting that hydrophobic interactions play a minor role. Extensive H-bonding, π-cation and electrostatic interactions are more plausible to explain the reversible bridging of mfp-3 films by collagen. [ABSTRACT FROM AUTHOR]

Mussel foot protein-1 (mfp-1) is an essential constituent of the protective cuticle covering all exposed portions of the byssus (plaque and the thread) that marine mussels use to attach to intertidal rocks. The reversible complexation of Fe3+ by the 3,4-dihydroxyphenylalanine (Dopa) side chains in mfp-1 in Mytilus californianus cuticle is responsible for its high extensibility (120%) as well as its stiffness (2 GPa) due to the formation of sacrificial bonds that help to dissipate energy and avoid accumulation of stresses in the material. We have investigated the interactions between Fe3+ and mfp-1 from two mussel species, M. californianus (Mc) and M. edulis (Me), using both surface sensitive and solution phase techniques. Our results show that although mfp-1 homologues from both species bind Fe3+, mfp-1 (Mc) contains Dopa with two distinct Fe3+-binding tendencies and prefers to form intramolecular complexes with Fe3+. In contrast, mfp-1 (Me) is better adapted to intermolecular Fe3+ binding by Dopa. Addition of Fe3+ did not significantly increase the cohesion energy between the mfp-1 (Mc) films at pH 5.5. However, iron appears to stabilize the cohesive bridging of mfp-1 (Mc) films at the physiologically relevant pH of 7.5, where most other mfps lose their ability to adhere reversibly. Understanding the molecular mechanisms underpinning the capacity of M. californianus cuticle to withstand twice the strain of M. edulis cuticle is important for engineering of tunable strain tolerant composite coatings for biomedical applications. [ABSTRACT FROM AUTHOR]

Propagation effects on Ku-band over an earth-space path is carried out at Kolkata, India, a tropical location, by receiving a Ku-band signal with horizontal plane polarization transmitted from the geostationary satellite NSS-6 (at 95°E). The amplitude of co-polar attenuation has been monitored along with the measurements of rain rate, rain drop size distribution and height profile of rain rate. The cross-polar enhancement of the signal is also monitored by receiving the same signal in orthogonal direction with another identical receiver. The experimental observations are used to study the effect of melting layer on both co-polar attenuation and cross-polar enhancement for the rain events observed during 2012-2013. Melting layer is indicated by the bright band signature in vertical profile of rain rate. The ground based drop size measurements indicate that the stratiform rain has more number of small drops whereas convective rain composed of large rain drops. The results indicate that the depolarization due to melting layer is more dominant compared to that due to the drop deformation mechanism at low rain rates. [ABSTRACT FROM AUTHOR]

Highlights: [•] Microwave radiometric observations are used to nowcast heavy rain events. [•] Brightness temperatures of 22.24GHz and 58GHz show concurrent change before rain. [•] Brightness temperature derivatives indicate favorable conditions for imminent rain. [•] The prediction technique generates alarm 25min before rain for 90% of cases. [ABSTRACT FROM AUTHOR]

Hydroxy-9,10-anthraquinones are structural analogues of anthracycline anticancer drugs showing similarity in physicochemical attributes, electrochemical behavior and biophysical interactions. 1,2-dihydroxy-9,10-anthraquinone (Q) and its complexes with Cu(II)/Ni(II) were studied for γ radiation induced modification of DNA in Chinese Hamster V79 cells. The amount of double stranded DNA remaining was ascertained by fluorometric analysis of DNA unwinding using ethidium bromide. Modification of double stranded DNA increased in the presence of Q and Cu(II)-Q when cells were irradiated (0-4.2 Gray). Ni(II)-Q was not that effective. Changing incubation time before recovery of DNA from cells there was evidence for DNA repair that was least for Cu(II)-Q treated cells. Minimum repair in case of Cu(II)-Q treated cells suggest the compound either assists radiation induced damage of agents responsible for repair or interacts with species like HO that assist in repair. Since a hydroxy-9,10-anthraquinone and its Cu(II) complex show radiosensitizing property, anthracyclines that contain a hydroxy-9,10-anthraquinone as the core moiety could also be tried as radiosensitizers in treating cancer. Graphical Abstract: .[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Electrochemical behavior of the anticancer drug doxorubicin hydrochloride was studied using cyclic voltammetry in aqueous medium using Hepes buffer (pH~7.4). At this pH, doxorubicin hydrochloride undergoes a reversible two-electron reduction with E1/2 value -665 ± 5 mV (versus Ag/AgCl, saturated KCl). Depending on scan rates, processes were either quasireversible (at low scan rates) or near perfect reversible (at high scan rates). This difference in behavior of doxorubicin hydrochloride with scan rate studied over the same potential range speaks of differences in electron transfer processes in doxorubicin hydrochloride. Attempt was made to identify and understand the species involved using simulation. The information obtained was used to study the interaction of doxorubicin hydrochloride with calf thymus DNA. Cathodic peak current gradually decreased as more calf thymus DNA was added. The decrease in cathodic peak current was used to estimate the interaction of the drug with calf thymus DNA. Nonlinear curve fit analysis was applied to evaluate the intrinsic binding constant and site size of interaction that was compared with previous results on doxorubicin hydrochloride-DNA interaction monitored by cyclic voltammetry or spectroscopic techniques [ABSTRACT FROM AUTHOR]

Geckos are highly efficient climbersand can run over any kindof surface with impeccable dexterity due to the typical design oftheir hierarchical foot structure. We have fabricated tilted, i.e.,asymmetric, poly(dimethylsiloxane) (PDMS) microflaps of two differentdensities that mimic the function of the micrometer sized setae onthe gecko foot pad. The adhesive properties of these microflaps wereinvestigated in a modified surface forces apparatus; both for normalpure loading and unloading (detachment), as well as unloading afterthe surfaces were sheared, both along and against the tilt direction.The tilted microflaps showed directional, i.e., anisotropic adhesivebehavior when sheared against an optically smooth (RMS roughness ≈10 ± 8 nm) SiO2surface. Enhanced adhesion was measuredafter shearing the flaps along the tilted (gripping) direction andlow adhesion when sheared against the tilted (releasing) direction.A Johnson–Kendall–Roberts (JKR) theory using an effectivesurface energy and modulus of rigidity (stiffness) quantitativelydescribed the contact mechanics of the tilted microflaps against theSiO2surface. We also find an increasing adhesion and stick–slipof the surfaces during detachment which we explain qualitatively interms of the density of flaps, considering it to increase from 0%(no flaps, smooth surface) to 100% (close-packed flaps, effectivelysmooth surface). Large energy dissipation at the PDMS–silicainterface caused by the viscoelastic behavior of the polymer resultsin stick–slip peeling and hence an enhanced adhesion energyis observed during the separation of the microflaps surface from thesmooth SiO2surface after shearing of the surfaces. Forstructured multiple contact surfaces, hysteresis as manifested bydifferent loading and unloading paths can be due entirely to the elasticJKR micro-contacts. These results have importantimplications in the design of biomimetic adhesives. [ABSTRACT FROM AUTHOR]

Abstract: The effect of the earth's atmosphere on radio waves propagating over an earth-space path is a major concern in the design and performance of satellite communications systems. Some characteristics of cloud and its effect on signal propagation has been studied using multi-wavelength radiometer at a tropical location of Kolkata, India. The liquid water content profile shows high values at higher altitude during pre-monsoon season indicating the presence of cloud above zero degree isotherm. Significant change in attenuation value is observed for same liquid water content due to change in temperature and accordingly a suitable relationship is obtained for the present location. The measurements indicate that ~4dB and ~12dB attenuation is caused due to cloud at 0.01% outage probability at the Ka and V band, respectively. ITU-R model is found to be overestimating the cloud attenuation over this location and indicate the need for more experimental measurement from tropical region. [Copyright &y& Elsevier]

Normal (e.g., adhesion) and lateral(friction) forces were measuredbetween physisorbedand chemicallygrafted layers of hyaluronic acid (HA), an anionic polyelectrolytein the presence of lubricin (Lub), a mucinous glycoprotein, on micasurfaces using a surface forces apparatus (SFA). This work demonstratesthat high friction coefficients between the surfaces do not necessarilycorrelate with surface damage and that chemicallygrafted HA acts synergistically with Lub to provide friction reductionand enhanced wear protection to the surfaces. Surface immobilizationof HA by grafting is necessary for such wear protection. Increasingthe concentration of Lub enhances the threshold load that a chemicallygrafted HA surface can be subjected to before the onset of wear. Additionof Lub does not have any beneficial effect if HA is physisorbedto the mica surfaces. Damage occurs at loads less than 1 mN regardlessof the amount of Lub, indicating that the molecules in the bulk playlittle or no role in protecting the surfaces from damage. Lub penetratesinto the chemicallybound HA to form a visco-elasticgel that reduces the coefficient of friction as well as boosts thestrength of the surface against abrasive wear (damage). [ABSTRACT FROM AUTHOR]

Obesity, sleep apnea syndrome and hypothyroidism cause management of mechanical ventilation and weaning a difficult task. We report management of mechanical ventilation and subsequent weaning of a morbidly obese lady of BMI 42 kg/m2 with hypothyroidism and sleep apnea for 52 days. To make the matter worse, she had accidental extubations, multiple cardiac arrests, pneumonia and renal dysfunction during her ICU stay. [ABSTRACT FROM AUTHOR]

Lightning is one of the most severe weather events causing significant loss of human lives and resources. Increasing number of lightning fatalities due to recent climatic changes is emerging out to be a serious concern for India during last few years. Proper characterization and parameterization of the same, therefore, is extremely crucial. However, lightning is an extremely dynamic phenomenon having enormous spatio‐temporal inhomogeneity especially over such a vast country like India with varied topographic and climatological features. Therefore, proper parameterization of lightning activity over India needs consideration of different lightning climatologies. This study has attempted to resolve the issue by regionalizing Indian subcontinent in different lightning climatologies based on lightning density and associated atmospheric variables that is, CAPE, specific humidity at different pressure levels, temperature, k index and cloud particle size and identified seven distinct lightning climatologies over India. A regression model is proposed for estimating the annual and seasonal (monsoon and pre‐monsoon) lightning activities over the seven resulting lightning zones based on the said atmospheric variables using machine learning techniques. Four machine learning models have been tested among which Random forest has shown the best accuracy. The regression model has shown an R‐squared score of 0.81 during monsoon season and 0.71 during the pre‐monsoon. The atmospheric features based on their influences on the lightning activity in these seven climatologies has been ranked which presented the evidences of largely varied interplay between different atmospheric variables and lightning over different parts of the country and during different seasons. [ABSTRACT FROM AUTHOR]

Here, we explore the different characteristics of a possible coupling between tropospheric and ionospheric activities during the impact of tropical cyclones (TC) like Amphan and Nisarga in the Indian subcontinent. We have analyzed the effect of TCs Amphan and Nisarga on the low latitude ionosphere using the measurements from several IGS stations around India and a GPS + NavIC station in Indore, India. For the first time, this study assesses the impact of tropical cyclones on the equatorial ionosphere using both GPS and NavIC. After the landfall of TC Amphan, the VTEC analysis shows a significant drop from nominal values in both NavIC as well in GPS by 5.1 TECU and 3.6 TECU, respectively. In contrast to TC Amphan, Nisarga showed a rise in VTEC which ranged from 0.9 TECU in GPS to 1.7 - 5 TECU in NavIC satellites except for PRN6. The paper examines Outgoing Longwave Radiation as a proxy to the convective activity which may be responsible for the ionospheric variation through the generation of gravity waves. In addition, the horizontal neutral wind observations at the location of TC landfall confirm the presence of ionospheric disturbances. VTEC perturbation analysis using a band-pass filter reveals a variation in differential TEC values between ± 0.4 and ± 0.8 based on the IGS station measurements. This indicates that the gravity wave is one of the responsible mechanisms for the lower–upper atmospheric coupling during both cyclones. [ABSTRACT FROM AUTHOR]

Abstract: Melting layer height, which is normally assumed to be the limits of rain region, is an important parameter to consider the performance of earth space communication link above 10GHz. In this paper, the variation of melting layer observed by a vertically looking Micro Rain Radar (MRR) for 3years has been presented for two different climatic locations in Indian tropical region — Shillong (25°34′ N, 91°53′ E, 1050m) and Trivandrum (8°29′ N, 76°57′ E, 4m). The analyses show that the variation is quite significant for different months in Shillong but not for Trivandrum. The height of melting layer shows a strong correlation with ground temperature of these locations. The results agree well with the long term Tropical Rainfall Measuring Mission (TRMM) measurements of melting layer indicating suitability of using TRMM data for such study. A comparison of MRR with the nearest Radiosonde measurement indicates that MRR can have potential application in the study of zero degree isotherm height in rainy conditions. Results also clearly indicate that the assumption of constant rain height is not a valid one for all tropical locations. [Copyright &y& Elsevier]

The anthracycline drugs adriamycin and daunorubicin, efficient in the treatment of various human cancers, form strong intercalation complexes with DNA. The therapeutic efficacy and toxicity of such anticancer drugs are governed by biochemical reactions of the core dihydroxy-9,10-anthraquinone unit. The high cost and toxic side effects of anthracycline drugs limit their use in cancer therapy. For a few decades, efforts have been made to find cheap, less toxic yet efficient analogues of anthracyclines. This work on 1,4-dihydroxy-9,10-anthraquinone (QH), a simple analogue of the anthracyclines, was carried out to compare its biochemical properties with anthracyclines. UV-Vis and fluorescence spectroscopic methods were used to analyze interaction of the compound with calf thymus DNA. The data were used to evaluate the binding constant and site size. [ABSTRACT FROM AUTHOR]

The electron transfer reactions involving quinones, hydroquinones, and catechols are very important in many areas of chemistry, especially in biological systems. The therapeutic efficiency as well as toxicity of anthracycline anticancer drugs, a class of anthraquinones, is governed by their electrochemical properties. Other quinones serve as important functional moiety in various biological systems like electron-proton carriers in the respiratory chain and their involvement in photosynthetic electron flow systems. The present paper summarizes literatures on the reduction of quinones in different solvents under various conditions using different electrochemical methods. The influence of different reaction conditions including pH of the media, nature of supporting electrolytes, nature of other additives, intramolecular or intermolecular hydrogen bonding, ion pair formation, polarity of the solvents, stabilization of the semiquinone and quinone dianion, catalytic property, and adsorption at the electrode surface, are discussed and relationships between reaction conditions and products formed have been presented. [ABSTRACT FROM AUTHOR]

The anthracycline drugs, adriamycin and daunorubicin, efficient in the treatment of various human cancers, form strong intercalation complexes with DNA. The therapeutic efficiency and toxic properties of the drugs are associated with electron transfer processes, which correlate well with the redox behaviour of the compounds. Sodium 1,4-dihydroxy 9,10-anthraquinone-2-sulphonate (sodium quinizarin-2-sulphonate, NaLH2) (Na-Qz-2S) is a molecule that resembles anthracycline drugs and has a simpler structure in comparison to these drugs. Two electrons in the course of chemical action reduce this molecule like the anthracyclines. Electrochemical methods were used to identify this process. UV-Vis and fluorescence spectroscopy were used to analyse binding of the compound to calf thymus DNA. The binding constant and site size were evaluated for Na-Qz-2S and the same compared to that of the anthracyclines. Such comparisons are essential in order to understand whether the simpler hydroxy-anthraquinones can be a substitute for anthracycline drugs in cancer chemotherapy. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: The microstructure of rain has been studied with observations using a vertical looking Micro Rain Radar (MRR) at Ahmedabad (23.06°N, 72.62°E), a tropical location in the Indian region. The rain height, derived from the bright band signature of melting layer of radar reflectivity profile, is found to be variable between the heights 4600m and 5200m. The change in the nature of rain, classified on the basis of radar reflectivity, is also observed through the MRR. It has been found that there are three types of rain, namely, convective, mixed and stratiform rain, prevailing with different vertical rain microstructures, such as, Drop Size Distribution (DSD), mean drop size, rain rate, liquid water content and average fall speed of the drops at different heights. It is observed that the vertical DSD profile is more inhomogeneous for mixed and stratiform type rain than for convective type rain. It is also found that the large number of drops of size <0.5mm is present in convective rain whereas in stratiform rain, drops concentration is appreciable up to 1mm. A comparison of measurements taken by ground based Disdrometer and that from the 200m level obtained from MRR shows good agreement for rain rate and DSD at smaller rain rate values. The results may be useful for understanding rain structures over this region. [Copyright &y& Elsevier]

A letter to the editor is presented from readers discussing the interesting characteristics of pressure and flow time waves they found upon evaluating three patients examined using ventilator waves and loops.

Abstract: Copper(II) forms a complex with sodium 1,4-dihydroxy-9,10-anthraquinone-2-sulphonate (sodium quinizarin-2-sulphonate, NaQSH2), an analogue of the core unit of anthracycline antibiotics used in the treatment of cancer. The 1:2 metal–ligand complex is formed in aqueous solution at neutral and acidic pH while in alkaline pH both 1:1 and 1:2 species are formed. The effective stability constant of the 1:2 metal–ligand complex is 9.64×1016 while that of the 1:1 metal–ligand complex is 9.4×109. The 1:2 complex Cu(NaQSH)2(H2O)2 was synthesized and characterized by different techniques in solid state and in solution. The complex Cu(NaQSH)2(H2O)2 interacts with calf thymus DNA which was studied by fluorescence spectroscopy. The binding constant and site size for the interaction with DNA were determined. [Copyright &y& Elsevier]

In the U.S. Wide Area Augmentation System, European Geostationary Navigation Overlay Service, and Indian Global Positioning System Aided Geo Augmented Navigation, a near real-time grid-based single-shell model is proposed to correct the ionospheric delay at the user aircrafts. The single-shell model is based on the assumption that the whole ionosphere is compressed at a fixed altitude at 350 km. This assumption may not be appropriate for the Indian region, which falls in the Equatorial Ionospheric Anomaly belt. In this paper, a two-shell model which incorporates two different shells, at 300- and 500-km altitudes, having different weights at different time domains has been implemented. A statistical comparison between single- and two-shell models has been done for all quiet days of year 2005. Based on the results, it is observed that there is at least 60% improvement in the performance of the two-shell model in comparison to the single-shell model for the Indian region. [ABSTRACT FROM AUTHOR]

The paper reports the influence of Ti on the oxidation behaviour of a new class of low-density L1 2 -strengthened Co-Ni-Al-Ta-Cr-Ti alloys. Oxide scales following the isothermal exposure for 1000 h at 800 °C, 900 °C, and 950 °C were characterized. Contrary to the expectation, increasing Ti content from 2 at% Ti to 4 at% Ti promotes significant oxidation resistance at all temperatures. The varying amount of Ti does not affect the overall sequence of oxide layers and phase chemistry but does affect the kinetics of the barrier layer formation. Two plausible reasons are discussed for the beneficial effect of Ti addition. • Role of Ti on the oxidation behaviour of a low-density Co-Ni-Al-Cr-Ta-Ti superalloy is presented. • Increment from 2 at% to 4 at% Ti improved the resistance at 800 ºC, 900 ºC and 950 ºC. • γ(fcc)-matrix of 4 at% Ti have higher Ni and Al content allowing thick alumina barrier. [ABSTRACT FROM AUTHOR]

Abstract: Ionizing radiation when allowed to fall upon cells or DNA, the radicals produced modify the base-pair region of the double strands. Radiation-induced double-strand modifications in calf thymus DNA were detected using Ni(II) and Fe(III) complexes of 1,2 dihydroxy 9,10 anthraquinone (DHA). 60Co was used as the source for γ-radiation and ethidium bromide (EB) as the fluorescent dye for detecting double-strand modifications caused in DNA. Results show that the Fe(III)–DHA complex is more efficient in modifying the base-pair region in double-stranded DNA in comparison to DHA or the Ni(II)–DHA complex. [Copyright &y& Elsevier]