Variation in the ionic composition in convective showers in Pune, India

Rain water samples of equal volume (100 ml) were collected sequentially from 5 convective shower events for a period of 2 years during the summer monsoon seasons of 1988 and 1989 at Pune. A marked decrease in the concentrations of soil-oriented elements Na+, K+, Ca2+ and Mg2+ was observed in the first few samples in all the events followed by a decrease in pH of the subsequent samples. Surprisingly, SO42- also showed similar variation, indicating that soil is contributing some SO42- in rain water. Washout process appears to be an important mechanism for the removal of the major ions from the atmosphere. However, rainout processes seem to be important for the removal of NO3- ions. The study points out that sequential sampling during a single shower appears to give better information about the relationship among H+, Na+, K+, Ca2+, Mg2+, SO42- and NO3- as compared to bulk sampling for longer duration

Generalized Mittag-Leffler Distributions and Processes for Applications in Astrophysics and Time Series Modeling

Geometric generalized Mittag-Leffler distributions having the Laplace transform $\frac{1}{1+\beta\log(1+t^\alpha)},00$ is introduced and its properties are discussed. Autoregressive processes with Mittag-Leffler and geometric generalized Mittag-Leffler marginal distributions are developed. Haubold and Mathai (2000) derived a closed form representation of the fractional kinetic equation and thermonuclear function in terms of Mittag-Leffler function. Saxena et al (2002, 2004a,b) extended the result and derived the solutions of a number of fractional kinetic equations in terms of generalized Mittag-Leffler functions. These results are useful in explaining various fundamental laws of physics. Here we develop first-order autoregressive time series models and the properties are explored. The results have applications in various areas like astrophysics, space sciences, meteorology, financial modeling and reliability modeling.Comment: 12 pages, LaTe

Ground-based salt seeding in Tamil nadu state, south India, 1973-1977

A long series of ground-based salt seeding experiments in north India during the southwest monsoonseasons (June-September) of 1957-66 showed significant increases of about 20 percent in rainfall on seeded days (Ramana Murty and Biswas, 1968). In September of 1974, salt seeding from aircraft on isolated maritime warm cumulus clouds within 50 km off the coast at Bombay(18 15’N, 72v 49’D, II m ASL) was followed by increases in radar echo area coverage in the vertical and in echo intensity (Chatterjee et al., 1978). seek similar results in a different area, a randomized salt-seeding experiment, using a single ground-based generator, was conducted in 1973 and 1975-77 just west of Madras, on the Bengal coast 1,000 km southeast of Bombay. There in the state of Tamil Nadu, South India, the main rainy season is during the northeast monsoon(Oct-Dec), whereas in most parts of India, about 75 percent of the annual rainfall is received during the southwest monsoon(Ananthakrishnan, 1977

Multi-scale simulation of the nano-metric cutting process

Molecular dynamics (MD) simulation and the finite element (FE) method are two popular numerical techniques for the simulation of machining processes. The two methods have their own strengths and limitations. MD simulation can cover the phenomena occurring at nano-metric scale but is limited by the computational cost and capacity, whilst the FE method is suitable for modelling meso- to macro-scale machining and for simulating macro-parameters, such as the temperature in a cutting zone, the stress/strain distribution and cutting forces, etc. With the successful application of multi-scale simulations in many research fields, the application of simulation to the machining processes is emerging, particularly in relation to machined surface generation and integrity formation, i.e. the machined surface roughness, residual stress, micro-hardness, microstructure and fatigue. Based on the quasi-continuum (QC) method, the multi-scale simulation of nano-metric cutting has been proposed. Cutting simulations are performed on single-crystal aluminium to investigate the chip formation, generation and propagation of the material dislocation during the cutting process. In addition, the effect of the tool rake angle on the cutting force and internal stress under the workpiece surface is investigated: The cutting force and internal stress in the workpiece material decrease with the increase of the rake angle. Finally, to ease multi-scale modelling and its simulation steps and to increase their speed, a computationally efficient MATLAB-based programme has been developed, which facilitates the geometrical modelling of cutting, the simulation conditions, the implementation of simulation and the analysis of results within a unified integrated virtual-simulation environment

Atmospheric aerosol characteristic studies at Pune and Thiruvananthapuram during INDOEX programme - 1998

Total suspended particulates (TSP) and mass size distribution of aerosols were monitored by using a high-volume air sampler and a low-volume 9-stage Anderson sampler, respectively during March-April 1998 at Pune and during 5-9 January 1998 at Thiruvananthapuram. All these samples were extracted for water-and acid-soluble components using the standard extraction method. The water-soluble extracts were analysed for Cl, SO4, NO3, NH4, Na, K, Ca and Mg and acid-soluble extracts for Al, Fe, Mn, Cu, Zn, Pb, Cd, Ni and Sb. The concentration of TSP varied from 67 to 185 μg/m3 with an average of 122 μg/m3 at Pune and from 35 to 73 μg/m3 with an average of 57 μg/m3 at Thiruvananthapuram. The mass size distribution of aerosols showed bimodal distribution having one peak in coarse mode and the other in fine mode at both the locations. The results of the study are presented here

Studies of trace gases and Aitken Nuclei at inland and coastal stations - A part of INDOEX programme

As a part of the Indian Ocean Experiment (INDOEX) programme, ground-based measurements of trace gases (SO2, NO2, NH3 and O3) and Aitken Nuclei (AN) were carried out at Pune during March-April 1998. Also, measurements of surface ozone and AN were made during 5-10 January 1998, the inter comparison campaign of various instruments at Thiruvananthapuram. The mean concentrations of SO2, NO2, NH3 and O3 at Pune were 3.75, 5.81, 3.21 and 57.8 μg/m3 respectively and that of O3 at Thiruvananthapuram was 44 μg/m3. The average concentration of AN was about five times higher at Pune (19,000/cm3) than that at Thiruvananthapuram (4,400/cm3), indicating more pollution at Pune than at Thiruvananthapuram. The diurnal variation of surface ozone showed high concentrations during the day and low concentrations during the night at both the locations. Diurnal variation of AN at Pune showed a daytime maximum and a night-time minimum. Whereas, at Thiruvananthapuram night-time values were higher than the daytime values which can be attributed to the influence of the land and sea breeze

Complex Processes from Dynamical Architectures with Time-Scale Hierarchy

The idea that complex motor, perceptual, and cognitive behaviors are composed of smaller units, which are somehow brought into a meaningful relation, permeates the biological and life sciences. However, no principled framework defining the constituent elementary processes has been developed to this date. Consequently, functional configurations (or architectures) relating elementary processes and external influences are mostly piecemeal formulations suitable to particular instances only. Here, we develop a general dynamical framework for distinct functional architectures characterized by the time-scale separation of their constituents and evaluate their efficiency. Thereto, we build on the (phase) flow of a system, which prescribes the temporal evolution of its state variables. The phase flow topology allows for the unambiguous classification of qualitatively distinct processes, which we consider to represent the functional units or modes within the dynamical architecture. Using the example of a composite movement we illustrate how different architectures can be characterized by their degree of time scale separation between the internal elements of the architecture (i.e. the functional modes) and external interventions. We reveal a tradeoff of the interactions between internal and external influences, which offers a theoretical justification for the efficient composition of complex processes out of non-trivial elementary processes or functional modes

Aerobic Exercise during Pregnancy and Presence of Fetal-Maternal Heart Rate Synchronization

It has been shown that short-term direct interaction between maternal and fetal heart rates may take place and that this interaction is affected by the rate of maternal respiration. The aim of this study was to determine the effect of maternal aerobic exercise during pregnancy on the occurrence of fetal-maternal heart rate synchronization.In 40 pregnant women at the 36th week of gestation, 21 of whom exercised regularly, we acquired 18 min. RR interval time series obtained simultaneously in the mothers and their fetuses from magnetocardiographic recordings. The time series of the two groups were examined with respect to their heart rate variability, the maternal respiratory rate and the presence of synchronization epochs as determined on the basis of synchrograms. Surrogate data were used to assess whether the occurrence of synchronization was due to chance.In the original data, we found synchronization occurred less often in pregnancies in which the mothers had exercised regularly. These subjects also displayed higher combined fetal-maternal heart rate variability and lower maternal respiratory rates. Analysis of the surrogate data showed shorter epochs of synchronization and a lack of the phase coordination found between maternal and fetal beat timing in the original data.The results suggest that fetal-maternal heart rate coupling is present but generally weak. Maternal exercise has a damping effect on its occurrence, most likely due to an increase in beat-to-beat differences, higher vagal tone and slower breathing rates

Nicotinic acetylcholine receptor variants associated with susceptibility to chronic obstructive pulmonary disease: a meta-analysis

<p>Abstract</p> <p>Background</p> <p>Only 10-15% of smokers develop chronic obstructive pulmonary disease (COPD) which indicates genetic susceptibility to the disease. Recent studies suggested an association between COPD and polymorphisms in <it>CHRNA </it>coding subunits of nicotinic acetylcholine receptor. Herein, we performed a meta-analysis to clarify the impact of <it>CHRNA </it>variants on COPD.</p> <p>Methods</p> <p>We searched Web of Knowledge and Medline from 1990 through June 2011 for COPD gene studies reporting variants on <it>CHRNA</it>. Pooled odds ratios (ORs) were calculated using the major allele or genotype as reference group.</p> <p>Results</p> <p>Among seven reported variants in <it>CHRNA</it>, rs1051730 was finally analyzed with sufficient studies. Totally 3460 COPD and 11437 controls from 7 individual studies were pooled-analyzed. A-allele of rs1051730 was associated with an increased risk of COPD regardless of smoking exposure (pooled OR = 1.26, 95% CI 1.18-1.34, p < 10^-5). At the genotypic level, the ORs gradually increased per A-allele (OR = 1.27 and 1.50 for GA and AA respectively, p < 10^-5). Besides, AA genotype exhibited an association with reduced FEV1% predicted (mean difference 3.51%, 95%CI 0.87-6.16%, p = 0.009) and increased risk of emphysema (OR 1.93, 95%CI 1.29-2.90, p = 0.001).</p> <p>Conclusions</p> <p>Our findings suggest that rs1051730 in <it>CHRNA </it>is a susceptibility variant for COPD, in terms of both airway obstruction and parenchyma destruction.</p

Association of Impulsivity and Polymorphic MicroRNA-641 Target Sites in the SNAP-25 Gene.

Impulsivity is a personality trait of high impact and is connected with several types of maladaptive behavior and psychiatric diseases, such as attention deficit hyperactivity disorder, alcohol and drug abuse, as well as pathological gambling and mood disorders. Polymorphic variants of the SNAP-25 gene emerged as putative genetic components of impulsivity, as SNAP-25 protein plays an important role in the central nervous system, and its SNPs are associated with several psychiatric disorders. In this study we aimed to investigate if polymorphisms in the regulatory regions of the SNAP-25 gene are in association with normal variability of impulsivity. Genotypes and haplotypes of two polymorphisms in the promoter (rs6077690 and rs6039769) and two SNPs in the 3' UTR (rs3746544 and rs1051312) of the SNAP-25 gene were determined in a healthy Hungarian population (N = 901) using PCR-RFLP or real-time PCR in combination with sequence specific probes. Significant association was found between the T-T 3' UTR haplotype and impulsivity, whereas no association could be detected with genotypes or haplotypes of the promoter loci. According to sequence alignment, the polymorphisms in the 3' UTR of the gene alter the binding site of microRNA-641, which was analyzed by luciferase reporter system. It was observed that haplotypes altering one or two nucleotides in the binding site of the seed region of microRNA-641 significantly increased the amount of generated protein in vitro. These findings support the role of polymorphic SNAP-25 variants both at psychogenetic and molecular biological levels