Purification, characterization and molecular cloning of a monocot mannose-binding lectin from Remusatia vivipara with nematicidal activity

A mannose-binding lectin (RVL) was purified from the tubers of Remusatia vivipara, a monocot plant by single-step affinity chromatography on asialofetuin-Sepharose 4B. RVL agglutinated only rabbit erythrocytes and was inhibited by mucin, asialomucin, asialofetuin and thyroglobulin. Lectin activity was stable up to 80A degrees C and under wide range of pH (2.0-9.3). SDS-PAGE and gel filtration results showed the lectin is a homotetramer of Mr 49.5 kDa, but MALDI analysis showed two distinct peaks corresponding to subunit mass of 12 kDa and 12.7 kDa. Also the N-terminal sequencing gave two different sequences indicating presence of two polypeptide chains. Cloning of RVL gene indicated posttranslational cleavage of RVL precursor into two mature polypeptides of 116 and 117 amino-acid residues. Dynamic light scattering (DLS) and gel filtration studies together confirmed the homogeneity of the purified lectin and supported RVL as a dimer with Mr 49.5 kDa derived from single polypeptide precursor of 233 amino acids. Purified RVL exerts potent nematicidal activity on Meloidogyne incognita, a root knot nematode. Fluorescent confocal microscopic studies demonstrated the binding of RVL to specific regions of the alimentary-tract and exhibited a potent toxic effect on M. incognita. RVL-mucin complex failed to interact with the gut confirming the receptor mediated lectin interaction. Very high mortality (88%) rate was observed at lectin concentration as low as 30 A mu g/ml, suggesting its potential application in the development of nematode resistant transgenic-crops.

Applications of dimensional reduction to electroweak and QCD matter

When heated to high temperatures, the behavior of matter changes dramatically. The standard model fields go through phase transitions, where the strongly interacting quarks and gluons are liberated from their confinement to hadrons, and the Higgs field condensate melts, restoring the electroweak symmetry. The theoretical framework for describing matter at these extreme conditions is thermal field theory, combining relativistic field theory and quantum statistical mechanics. For static observables the physics is simplified at very high temperatures, and an effective three-dimensional theory can be used instead of the full four-dimensional one via a method called dimensional reduction. In this thesis dimensional reduction is applied to two distinct problems, the pressure of electroweak theory and the screening masses of mesonic operators in quantum chromodynamics (QCD). The introductory part contains a brief review of finite-temperature field theory, dimensional reduction and the central results, while the details of the computations are contained in the original research papers. The electroweak pressure is shown to converge well to a value slightly below the ideal gas result, whereas the pressure of the full standard model is dominated by the QCD pressure with worse convergence properties. For the mesonic screening masses a small positive perturbative correction is found, and the interpretation of dimensional reduction on the fermionic sector is discussed.

Long-term effects of physical activity level on changes in healthy body mass index over 12 years in young adult women

Objectives To examine the effects of overall level and timing of physical activity (PA) on changes from a healthy body mass index (BMI) category over 12 years in young adult women. Patients and Methods Participants in the Australian Longitudinal Study on Women's Health (younger cohort, born 1973-1978) completed surveys between 2000 (age 22-27 years) and 2012 (age 34-39 years). Physical activity was measured in 2000, 2003, 2006, and 2009 and was categorized as very low, low, active, or very active at each survey, and a cumulative PA score for this 9-year period was created. Logistic regression was used to examine relationships between PA accumulated across all surveys (cumulative PA model) and PA at each survey (critical periods PA model), with change in BMI category (from healthy to overweight or healthy to obese) from 2000 to 2012. Results In women with a healthy BMI in 2000, there were clear dose-response relationships between accumulated PA and transition to overweight (P=.03) and obesity (P<.01) between 2000 and 2012. The critical periods analysis indicated that very active levels of PA at the 2006 survey (when the women were 28-33 years old) and active or very active PA at the 2009 survey (age 31-36 years) were most protective against transitioning to overweight and obesity. Conclusion These findings confirm that maintenance of very high PA levels throughout young adulthood will significantly reduce the risk of becoming overweight or obese. There seems to be a critical period for maintaining high levels of activity at the life stage when many women face competing demands of caring for infants and young children.

Selection of intrusion detection system threshold bounds for effective sensor fusion

The motivation behind the fusion of Intrusion Detection Systems was the realization that with the increasing traffic and increasing complexity of attacks, none of the present day stand-alone Intrusion Detection Systems can meet the high demand for a very high detection rate and an extremely low false positive rate. Multi-sensor fusion can be used to meet these requirements by a refinement of the combined response of different Intrusion Detection Systems. In this paper, we show the design technique of sensor fusion to best utilize the useful response from multiple sensors by an appropriate adjustment of the fusion threshold. The threshold is generally chosen according to the past experiences or by an expert system. In this paper, we show that the choice of the threshold bounds according to the Chebyshev inequality principle performs better. This approach also helps to solve the problem of scalability and has the advantage of failsafe capability. This paper theoretically models the fusion of Intrusion Detection Systems for the purpose of proving the improvement in performance, supplemented with the empirical evaluation. The combination of complementary sensors is shown to detect more attacks than the individual components. Since the individual sensors chosen detect sufficiently different attacks, their result can be merged for improved performance. The combination is done in different ways like (i) taking all the alarms from each system and avoiding duplications, (ii) taking alarms from each system by fixing threshold bounds, and (iii) rule-based fusion with a priori knowledge of the individual sensor performance. A number of evaluation metrics are used, and the results indicate that there is an overall enhancement in the performance of the combined detector using sensor fusion incorporating the threshold bounds and significantly better performance using simple rule-based fusion.

Supercapacitor studies of electrochemically deposited PEDOT on stainless steel substrate

There has been increasing interest on various properties and applications of electronically conducting polymers. Polyethylenedioxythiophene (PEDOT) is an interesting polymer of this type as it exhibits very high ionic conductivity. In the present study, PEDOT has been electrochemically deposited on stainless steel (SS) substrate for supercapacitor studies. PEDOT/SS electrodes prepared in 0.1M H2SO4 in presence of a surfactant, sodium dodecylsulphate (SDS), have been found to yield higher specific capacitance (SC) than the electrodes prepared from neutral aqueous electrolyte. The effects of concentration of H(2)SO4(,) concentration of SDS, potential of deposition, and nature of supporting electrolytes used for capacitor studies on SC of the PEDOT/SS electrodes have been studied. SC values as high as 250 F/g in 1M oxalic acid have been obtained during the initial stages of cycling. However, there is a rapid decrease in SC on repeated charge-discharge cycling. Spectroscopic data reflect structural changes in PEDOT on extended cycling. (C) 2007 Wiley Periodicals, Inc.

Pathways to health : Determinants of health, health behaviour and health inequalities in early adulthood

There is increasing evidence that the origins of poor adult health and health inequalities can be traced back to circumstances preceding current socioeconomic position and living conditions. The life-course approach to examining the determinants of health has emphasised that exposure to adverse social and economic circumstances in earlier life or concurrent adverse circumstances due to unfavourable living conditions in earlier life may lead to poor health, health-damaging behaviour, disease or even premature death in adulthood. There is, however, still a lack of knowledge about the contribution of social and economic circumstances in childhood and youth to adult health and health inequalities, and even less is known about how environmental and behavioural factors in adulthood mediate the effects of earlier adverse experiences. The main purpose of this study was to deepen our understanding of the development of poor health, health-damaging behaviours and health inequalities during the life-course. Its aim was to find out which factors in earlier and current circumstances determine health, the most detrimental indicators of health behaviour (smoking, heavy drinking and obesity as a proxy for the balance between nutrition and exercise), and educational health differences in young adults in Finland. Following the ideas of the social pathway theory, it was assumed that childhood environment affects adult health and its proximal determinants via different pathways, including educational, work and family careers. Early adulthood was studied as a significant phase of life when many behavioural patterns and living conditions relevant to health are established. In addition, socioeconomic health inequalities seem to emerge rapidly when moving into adulthood; they are very small or non-existent in childhood and adolescence, but very marked by early middle age. The data of this study were collected in 2000 2001 as part of the Health 2000 Survey (N = 9,922), a cross-sectional and nationally representative health interview and examination survey. The main subset of data used in this thesis was the one comprising the age group 18 29 years (N = 1,894), which included information collected by standardised structured computer-aided interviews and self-administered questionnaires. The survey had a very high participation rate at almost 90% for the core questions. According to the results of this study, childhood circumstances predict the health of young adults. Almost all the childhood adversities studied were found to be associated with poor self-rated health and psychological distress in early adulthood, although fewer associations were found with the somatic morbidity typical of young adults. These effects seemed to be more or less independent of the young adult s own education. Childhood circumstances also had a strong effect on smoking and heavy drinking, although current circumstances and education in particular, played a role in mediating this effect. Parental smoking and alcohol abuse had an influence on the corresponding behaviours of offspring. Childhood circumstances had a role in the development of obesity and, to a lesser extent, overweight, particularly in women. The findings support the notion that parental education has a strong effect on early adult obesity, even independently of the young adult s own educational level. There were marked educational differences in self-rated health in early adulthood: those in the lowest educational category were most likely to have average or poorer health. Childhood social circumstances seemed to explain a substantial part of these educational differences. In addition, daily smoking and heavy drinking contributed substantially to educational health differences. However, the contribution of childhood circumstances was largely shared with health behaviours adopted by early adulthood. Employment also shared the effects of childhood circumstances on educational health differences. The results indicate that childhood circumstances are important in determining health, health behaviour and health inequalities in early adulthood. Early recognition of childhood adversities followed by relevant support measures may play an important role in preventing the unfortunate pathways leading to the development of poor health, health-damaging behaviour and health inequalities. It is crucially important to recognise the needs of children living in adverse circumstances as well as children of substance abusing parents. In addition, single-parent families would benefit from support. Differences in health and health behaviours between different sub-groups of the population mean that we can expect to see ever greater health differences when today s generation of young adults grows older. This presents a formidable challenge to national health and social policy as well as health promotion. Young adults with no more than primary level education are at greatest risk of poor health. Preventive policies should emphasise the role of low educational level as a key determinant of health-damaging behaviours and poor health. Keywords: health, health behaviour, health inequalities, life-course, socioeconomic position, education, childhood circumstances, self-rated health, psychological distress, somatic morbidity, smoking, heavy drinking, BMI, early adulthood

Genetic Mechanisms Underlying Autism Spectrum Disorders

Autism is a childhood-onset developmental disorder characterized by deficits in reciprocal social interaction, verbal and non-verbal communication, and dependence on routines and rituals. It belongs to a spectrum of disorders (autism spectrum disorders, ASDs) which share core symptoms but show considerable variation in severity. The whole spectrum affects 0.6-0.7% of children worldwide, inducing a substantial public health burden and causing suffering to the affected families. Despite having a very high heritability, ASDs have shown exceptional genetic heterogeneity, which has complicated the identification of risk variants and left the etiology largely unknown. However, recent studies suggest that rare, family-specific factors contribute significantly to the genetic basis of ASDs. In this study, we investigated the role of DISC1 (Disrupted-in-schizophrenia-1) in ASDs, and identified association with markers and haplotypes previously associated with psychiatric phenotypes. We identified four polymorphic micro-RNA target sites in the 3 UTR of DISC1, and showed that hsa-miR-559 regulates DISC1 expression in vitro in an allele-specific manner. We also analyzed an extended autism pedigree with genealogical roots in Central Finland reaching back to the 17th century. To take advantage of the beneficial characteristics of population isolates to gene mapping and reduced genetic heterogeneity observed in distantly related individuals, we performed a microsatellite-based genome-wide screen for linkage and linkage disequilibrium in this pedigree. We identified a putative autism susceptibility locus on chromosome 19p13.3 and obtained further support for previously reported loci at 1q23 and 15q11-q13. To follow-up these findings, we extended our study sample from the same sub-isolate and initiated a genome-wide analysis of homozygosity and allelic sharing using high-density SNP markers. We identified a small number of haplotypes shared by different subsets of the genealogically connected cases, along with convergent biological pathways from SNP and gene expression data, which highlighted axon guidance molecules in the pathogenesis of ASDs. In conclusion, the results obtained in this thesis show that multiple distinct genetic variants are responsible for the ASD phenotype even within single pedigrees from an isolated population. We suggest that targeted resequencing of the shared haplotypes, linkage regions, and other susceptibility loci is essential to identify the causal variants. We also report a possible micro-RNA mediated regulatory mechanism, which might partially explain the wide-range neurobiological effects of the DISC1 gene.

A chemical approach to an understanding of the fast ion conduction in silver iodide-silver oxysalt glasses

A number of AgI based fast ion conducting glasses, with a general formula AgI---Ag2O---MxOy (MxOy=MoO3, SeO3, WO3, V2O5, P2O5, GeO2, B2O3, As2O3, CrO3) have been studied. A chemical approach is made to investigate the origin of fast ion conduction in these glasses. An index known as Image tructural Image npinning Image umber, SUN (S), has been defined for the purpose, based on the unscreened nuclear charge of silver ions and the equilibrium lectronegativities of the halide-oxyanion matrix in these glasses. The variation of the glass transition temperature, Tg, conductivity, σ, and the energy of activation, Ea, with the concentration of AgI are discussed in the light of the structural unpinning number. Conductivities increase uniformly in any given glass series as a smooth function of S and level off at very high values. The entire range of conductivity appears to vary as ln Image , where ln σ0 corresponds roughly to the conductivity of the hypothetical AgI glass and “a” is a constant which could be obtained as the slope in the graph of ln Ea versus S. It is suggested that the increase in the concentration of AgI beyond 75–80 mole% in the glass is not advantageous from the conductivity point of view.

Unrealized expectations of jumps in volatility: An explanation to the low and time-varying predictive power of implied volatility

The low predictive power of implied volatility in forecasting the subsequently realized volatility is a well-documented empirical puzzle. As suggested by e.g. Feinstein (1989), Jackwerth and Rubinstein (1996), and Bates (1997), we test whether unrealized expectations of jumps in volatility could explain this phenomenon. Our findings show that expectations of infrequently occurring jumps in volatility are indeed priced in implied volatility. This has two important consequences. First, implied volatility is actually expected to exceed realized volatility over long periods of time only to be greatly less than realized volatility during infrequently occurring periods of very high volatility. Second, the slope coefficient in the classic forecasting regression of realized volatility on implied volatility is very sensitive to the discrepancy between ex ante expected and ex post realized jump frequencies. If the in-sample frequency of positive volatility jumps is lower than ex ante assessed by the market, the classic regression test tends to reject the hypothesis of informational efficiency even if markets are informationally effective.

Starburst in the ultraluminous galaxy Arp 220: Constraints from observations of radio recombination lines and continuum

We present observations of radio recombination lines (RRL) from the starburst galaxy Arp 220 at 8.1 GHz (H92 alpha) and 1.4 GHz (H167 alpha and H165 alpha) and at 84 GHz (H42 alpha), 96 GHz (H40 alpha) and 207 GHz (H31 alpha) using the Very Large Array and the IRAM 30 m telescope, respectively. RRLs were detected at all the frequencies except 1.4 GHz, where a sensitive upper limit was obtained. We also present continuum flux measurements at these frequencies as well as at 327 MHz made with the VLA. The continuum spectrum, which has a spectral index alpha similar to -0.6 (S-nu proportional to nu(alpha)) between 5 and 10 GHz, shows a break near 1.5 GHz, a prominent turnover below 500 MHz, and a flatter spectral index above 50 GHz. We show that a model with three components of ionized gas with different densities and area covering factors can consistently explain both RRL and continuum data. The total mass of ionized gas in the three components is 3.2 x 10(7) M., requiring 3 x 10(5) O5 stars with a total Lyman continuum production rate N-Lyc similar to 1.3 x 10(55) photons s(-1). The ratio of the expected to observed Br alpha and Br gamma fluxes implies a dust extinction A(V) similar to 45 mag. The derived Lyman continuum photon production rate implies a continuous star formation rate (SFR) averaged over the lifetime of OB stars of similar to 240 M yr(-1). The Lyman continuum photon Production rate of similar to 3% associated with the high-density H II regions implies a similar SFR at recent epochs (t < 10(5) yr). An alternative model of high-density gas, which cannot be excluded on the basis of the available data, predicts 10 times higher SFR at recent epochs. If confirmed, this model implies that star formation in Arp 220 consists of multiple starbursts of very high SFR (few times 10(3) M. yr(-1)) and short duration (similar to 10(5) yr). The similarity of IR excess, L-IR/L-Ly alpha similar to 24, in Arp 220 to values observed in starburst galaxies shows that most of the high luminosity of Arp 220 is due to the ongoing starburst rather than to a hidden active galactic nucleus (AGN). A comparison of the IR excesses in Arp 220, the Galaxy, and M33 indicates that the starburst in Arp 220 has an initial mass function that is similar to that in normal galaxies and has a duration longer than 107 yr. If there was no infall of gas during this period, then the star formation efficiency (SFE) in Arp 220 is similar to 50%. The high SFR and SFE in Arp 220 is consistent with their known dependences on mass and density of gas in star-forming regions of normal galaxies.

The hard-particle model for a dense granular flow down an inclined plane

Perfectly hard particles are those which experience an infinite repulsive force when they overlap, and no force when they do not overlap. In the hard-particle model, the only static state is the isostatic state where the forces between particles are statically determinate. In the flowing state, the interactions between particles are instantaneous because the time of contact approaches zero in the limit of infinite particle stiffness. Here, we discuss the development of a hard particle model for a realistic granular flow down an inclined plane, and examine its utility for predicting the salient features both qualitatively and quantitatively. We first discuss Discrete Element simulations, that even very dense flows of sand or glass beads with volume fraction between 0.5 and 0.58 are in the rapid flow regime, due to the very high particle stiffness. An important length scale in the shear flow of inelastic particles is the `conduction length' delta = (d/(1 - e(2))(1/2)), where d is the particle diameter and e is the coefficient of restitution. When the macroscopic scale h (height of the flowing layer) is larger than the conduction length, the rates of shear production and inelastic dissipation are nearly equal in the bulk of the flow, while the rate of conduction of energy is O((delta/h)(2)) smaller than the rate of dissipation of energy. Energy conduction is important in boundary layers of thickness delta at the top and bottom. The flow in the boundary layer at the top and bottom is examined using asymptotic analysis. We derive an exact relationship showing that the a boundary layer solution exists only if the volume fraction in the bulk decreases as the angle of inclination is increased. In the opposite case, where the volume fraction increases as the angle of inclination is increased, there is no boundary layer solution. The boundary layer theory also provides us with a way of understanding the cessation of flow when at a given angle of inclination when the height of the layer is decreased below a value h(stop), which is a function of the angle of inclination. There is dissipation of energy due to particle collisions in the flow as well as due to particle collisions with the base, and the fraction of energy dissipation in the base increases as the thickness decreases. When the shear production in the flow cannot compensate for the additional energy drawn out of the flow due to the wall collisions, the temperature decreases to zero and the flow stops. Scaling relations can be derived for h(stop) as a function of angle of inclination.

Functional Surfaces for Microfluidics in Proteomic Analysis

Microchips for use in biomolecular analysis show a lot of promise for medical diagnostics and biomedical basic research. Among the potential advantages are more sensitive and faster analyses as well as reduced cost and sample consumption. Due to scaling laws, the surface are to volume ratios of microfluidic chips is very high. Because of this, tailoring the surface properties and surface functionalization are very important technical issues for microchip development. This thesis studies two different types of functional surfaces, surfaces for open surface capillary microfluidics and surfaces for surface assisted laser desorption ionization mass spectrometry, and combinations thereof. Open surface capillary microfluidics can be used to transport and control liquid samples on easily accessible open surfaces simply based on surface forces, without any connections to pumps or electrical power sources. Capillary filling of open partially wetting grooves is shown to be possible with certain geometries, aspect ratios and contact angles, and a theoretical model is developed to identify complete channel filling domains, as well as partial filling domains. On the other hand, partially wetting surfaces with triangular microstructures can be used for achieving directional wetting, where the water droplets do not spread isotropically, but instead only spread to a predetermined sector. Furthermore, by patterning completely wetting and superhydrophobic areas on the same surface, complex droplet shapes are achieved, as the water stretches to make contact with the wetting surface, but does not enter into the superhydrophobic domains. Surfaces for surface assisted laser desorption ionization mass spectrometry are developed by applying various active thin film coatings on multiple substrates, in order to separate surface and bulk effects. Clear differences are observed between both surface and substrate layers. The best performance surfaces consisted of amorphous silicon coating and an inorganic-organic hybrid substrate, with nanopillars and nanopores. These surfaces are used for matrix-free ionization of drugs, peptides and proteins, and for some analytes, the detection limits were in the high attomoles. Microfluidics and laser desorption ionization surfaces are combined on a functionalized drying platforms, where the surface is used to control the shape of the deposited analyte droplet, and the shape of the initial analyte droplet affects the dried droplet solute deposition pattern. The deposited droplets can then directly detected by mass spectrometry. Utilizing this approach, results of analyte concentration, splitting and separation are demonstrated.

Improved hybrid elements for structural analysis

Hybrid elements, which are based on a two-field variational formulation with the displacements and stresses interpolated separately, are known to deliver very high accuracy, and to alleviate to a large extent problems of locking that plague standard displacement-based formulations. The choice of the stress interpolation functions is of course critical in ensuring the high accuracy and robustness of the method. Generally, an attempt is made to keep the stress interpolation to the minimum number of terms that will ensure that the stiffness matrix has no spurious zero-energy modes, since it is known that the stiffness increases with the increase in the number of terms. Although using such a strategy of keeping the number of interpolation terms to a minimum works very well in static problems, it results either in instabilities or fails to converge in transient problems. This is because choosing the stress interpolation functions merely on the basis of removing spurious energy modes can violate some basic principles that interpolation functions should obey. In this work, we address the issue of choosing the interpolation functions based on such basic principles of interpolation theory and mechanics. Although this procedure results in the use of more number of terms than the minimum (and hence in slightly increased stiffness) in many elements, we show that the performance continues to be far superior to displacement-based formulations, and, more importantly, that it also results in considerably increased robustness.

Terahertz Time Domain Spectroscopy to Detect Low-Frequency Vibrations of Double-Walled Carbon Nanotubes

We have measured the frequency-dependent real index of refraction and extinction coefficient (and hence the complex dielectric function) of a free-standing double-walled carbon nanotube film of thickness 200 nm by using terahertz time domain spectroscopy in the frequency range 0.1 to 2.5 THz. The real index of refraction and extinction coefficient have very high values of approximately 52 and 35, respectively, at 0.1 THz, which decrease at higher frequencies. Two low-frequency phonon modes of the carbon nanotubes at 0.45 and 0.75 THz were clearly observed for the first time in the real and imaginary parts of the complex dielectric function along with a broad resonance centred at around 1.45 THz, the latter being similar to that in single-walled carbon nanotubes assigned to electronic excitations. Our experiments bring out a possible application of double-walled carbon nanotube films as a neutral density filter in the THz range.

Surprising observation of large anthropogenic aerosol fraction over the ``near-pristine'' southern Bay of Bengal: Climate implications

The Bay of Bengal (BoB), a small oceanic region surrounded by landmasses with distinct natural and anthropogenic activities and under the influence of seasonally changing airmass types, is characterized by a rather complex and highly heterogeneous aerosol environment. Concurrent measurements of the physical, optical, and chemical (offline analysis) properties of BoB aerosols, made onboard extensive ship-cruises and aircraft sorties during Integrated Campaign for Aerosols, gases and Radiation Budget of March-April 2006, and satellite-retrieved aerosol optical depths and derived parameters, were synthesized following a synergistic approach to delineate the anthropogenic fraction to the composite aerosol parameters and its spatial variation. Quite interestingly and contrary to the general belief, our studies revealed that, despite of the very high aerosol loading (in the marine atmospheric boundary layer as well as in the vertical column) over the northern BoB and a steep decreasing gradient toward the southern latitudes, the anthropogenic fraction showed a steady increase from North to South (where no obvious anthropogenic source regions exist). Consequently, the direct radiative forcing at the top of the atmosphere due to anthropogenic aerosols remained nearly constant over the entire BoB with values in the range from -3.3 to -3.6 Wm(-2). This interesting finding, beyond doubts calls for a better understanding of the complex aerosol system over the BoB through more focused field campaigns.