Aerosol–Cloud Interaction: A Case Study

MODerate Resolution Imaging Spectroradiometer (MODIS) retrieved aerosol and cloud products at the nine selected stations over Western Himalayan and Deccan Plateau regions were inferred to bring out their salient features and to investigate aerosol–cloud interaction. Annually, Ångström exponent (AE) decreases with aerosol optical depth (AOD) while in winter it increases with AOD at most of the stations. Results bring out positive and/or negative association between AOD and almost all the cloud parameters over the selected stations. Aerosol indirect effect (AIE) is quantified for fixed liquid water path (LWP) bins ranging from 1 to 350 g/m2 at an interval of 25 g/m2 for three categories of stations, viz., CAT‐H, CAT‐M, and CAT‐L based on heavy, moderate, and low aerosol loading, respectively. AIE is negative at CAT‐H (−0.04 ± 0.14), while it is positive at CAT‐M (0.01 ± 0.07) and CAT‐L (0.10 ± 0.48). During winter, negative AIE has been observed for all three categories. In pre‐monsoon, the majority of LWP bins (86% at CAT‐H and 60% at CAT‐M) showed positive AIE, while about 71% of LWP bins indicted negative AIE at CAT‐L. However, during monsoon about 63–71% of LWP bins showed negative AIE at these categories. Study elucidates the influence of factors like cloud type, cloud dynamics/thermodynamics on aerosol–cloud interactions

Validation of MODIS Aerosol Optical Depth Retrievals over a Tropical Urban Site, Pune, India

In the present paper, MODIS (Terra and Aqua; level 2, collection 5) derived aerosoloptical depths (AODs) are compared with the ground-based measurements obtained from AERONET (level 2.0) and Microtops - II sun-photometer over a tropical urban station, Pune (18 deg 32'N; 73 deg 49'E, 559 m amsl). This is the first ever systematic validation of the MODIS aerosol products over Pune. Analysis of the data indicates that the Terra and Aqua MODIS AOD retrievals at 550 nm have good correlations with the AERONET and Microtops - II sun-photometer AOD measurements. During winter the linear regression correlation coefficients for MODIS products against AERONET measurements are 0.79 for Terra and 0.62 for Aqua; however for premonsoon, the corresponding coefficients are 0.78 and 0.74. Similarly, the linear regression correlation coefficients for Microtops measurements against MODIS products are 0.72 and 0.93 for Terra and Aqua data respectively during winter and are 0.78 and 0.75 during pre-monsoon. On yearly basis in 2008-2009, correlation coefficients for MODIS products against AERONET measurements are 0.80 and 0.78 for Terra and Aqua respectively while the corresponding coefficients are 0.70 and 0.73 during 2009-2010. The regressed intercepts with MODIS vs. AERONET are 0.09 for Terra and 0.05 for Aqua during winter whereas their values are 0.04 and 0.07 during pre-monsoon. However, MODIS AODs are found to underestimate during winter and overestimate during pre-monsoon with respect to AERONET and Microtops measurements having slopes 0.63 (Terra) and 0.74 (Aqua) during winter and 0.97 (Terra) and 0.94 (Aqua) during pre-monsoon. Wavelength dependency of Single Scattering Albedo (SSA) shows presence of absorbing and scattering aerosol particles. For winter, SSA decreases with wavelength with the values 0.86 +/- 0.03 at 440 nm and 0.82 +/- 0.04 at 1020nm. In pre-monsoon, it increases with wavelength (SSA is 0.87 +/- 0.02 at 440nm; and 0.88 +/-0.04 at 1020 nm)

A New Approach for One-step Synthesis of Perovskite:fullerene Bulk Heterojunction Using Surfactant Free Microemulsion in Slot Die Method

Organometallic halide perovskite based solar cells are considered as the foundation of future photovoltaic technology. In these types of solar cells, it has been emphasized that the bulk heterojunction active layer architecture may show superior performance than the bilayer active layer architecture due to the increase in the interfacial area by intermixing both donor and acceptor phases in the bulk heterojunction. Organometallic halide perovskite with suitable acceptor in bulk heterojunction architecture can be a promising active layer in perovskite solar cells. Conventionally, the perovskite and acceptor are mixed together in a single solvent before thin film formation. Though this offers a one-step synthesis way, limited solubility of perovskite and acceptor in single solvent puts major constraint on the formation of bulk heterojunction through one-step solution processable method. This paper describes a new way of one-step synthesis of bulk heterojunction using surfactant free microemulsion in slot die method, which removes the constraint of limited solubility of the two phases in a single solvent. Emulsion of DMSO (solvent for CH3NH3PbI3) and cyclohexane (solvent for PCBM) stabilized with acetone was used for making perovskite:fullerene bulk heterojunction. Solvent evaporation dynamics has been simulated to get deeper understanding of emulsion solidification leading to bulk heterojunction formation. Structural and optical studies support the formation of bulk heterojunction for efficient charge separation at donor:acceptor interfaces. A perovskite solar cell employing this bulk heterojunction has also been reported

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Performance analysis of Strain sensor based on Fiber Bragg Grating

A fiber Bragg grating can be worked as reflector, it is constructed in a short section of optical fiber that reflects light of specific wavelength and allow to pass remaining wavelengths. This is possible by creating a periodic change in refractive index within the fiber core. The change in the modal index of fiber caused due to strain results in a Bragg wavelength. This work describes performance of Fiber Bragg Gratings as a strain sensor at 1550nm wavelength is considered for simulation, corresponding dynamic strain and wavelength shifts are analysed. This performance analysis is useful especially for intrusion detection system where environments are harsh. This sensor is compatible with data communication system and can be used for remote sensing

Farnesol Sensitivity of Serum Induced Yeast to Hyphae Morphogenesis: A Study on Fifty Clinical Isolates of Candida albicans

Aim: Objective of this study was to examine farnesol sensitivity of yeast to hyphae dimorphism in clinical isolates of Candida albicans. Study Design: Variations in virulence attributes contribute to variations in pathogenicity of C. albicans. Ability to switch from yeast to hyphae morphology is an important virulence factor. Farnesol, a quorum sensing molecule is known to play an important role in the regulation of C. albicans morphogenesis. Analysis of farnesol susceptibility of yeast to hyphae conversion may reveal a factor responsible for variation in pathogenicity among clinical isolates of C. albicans. Place and Duration of Study: SCG Medical College & SGGS Memorial Hospital, and School of Life Sciences, SRTM University, Nanded, India. Duration of this study was, December 2008 to December 2010. Methodology: Fifty clinical isolates of C. albicans were recovered from body fluids (such as, sputum, blood, urine, vaginal swab, tracheal swab, throat swab, feces, pus and cerebrospinal fluid, etc.) of patients with different clinical manifestations, in the tertiary care center hospital. Presumptive identification of C. albicans was done on HiCHROM agar- Candida, while confirmation was done by Germ tube formation assay, Carbohydrate assimilation and Corn meal agar test. Serum induced yeast to hyphae morphogenesis in C. albicans was performed in 96 well plates. Recent methodology of micro broth dilution was used for farnesol susceptibility testing in fifty clinical isolates. Results: Farnesol prevented hyphae formation in a concentration dependent manner, in the range 25 to 400 μM. Inhibition of ≥ 50% hyphae was considered as significant reduction in morphogenesis. MIC70 for farnesol mediated inhibition of morphogenesis in C. albicans was at 200 μM. Mean values for percentage inhibition of morphogenesis in fifty strains was compared by analysis of variance (ANOVA). P = 0.05 was considered significant. Conclusion: Susceptibility of yeast to hyphae morphogenesis to the quorum sensing molecule farnesol, varied significantly among clinical isolates of C. albicans. We hypothesize that variation in farnesol sensitivity may be a factor responsible for variable dissemination and infection ability of C. albicans