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This article reports the influence of substrate bias during growth and of hydrogen and nitrogen incorporation on density of states [N (EF)] and field-emission threshold (Eturn-on) in tetrahedral amorphous carbon (ta-C) films, deposited using an S-bend filtered cathodic vacuum arc process. The variation in negative substrate bias from −20 to −200 V was found to initially lead to a small decrease in N (EF) and Eturn-on, and a small increase in the emission current density (J) at 12.5 V/μm in the case of as-grown ta-C films; beyond −200 V substrate bias there is a reversal in the trend. The values of N (EF)=1.3×1017 cm−3 eV−1, Eturn-on=8.3 V/μm, and J=6.19 mA/cm2 were observed at −200 V substrate bias. However at −300 V the properties were not very different from those at −200 V substrate bias and so with a view to use the higher energy, hydrogen and nitrogen incorporation studies were carried out in this condition. It was observed that there was further enhancement in properties with hydrogen and nitrogen i...

In the present work, a mathematical model of predator–prey ecological interaction with infected prey is investigated. A saturation incidence function is used to model the behavioral change of the susceptible individuals when their number increases or due to the crowding effect of the infected individuals [V. Capasso, G. Serio, A generalization of the Kermack–McKendrick deterministic epidemic model, Math. Biosci. 42 (1978) 41–61]. Stability criteria for the infection-free and the endemic equilibria are deduced in terms of system parameters. The basic model is then modified to incorporate a time delay, describing a latency period. Stability and bifurcation analysis of the resulting delay differential equation model is carried out and ranges of the delay inducing stability and as well as instability for the system are found. Finally, a stability analysis of the bifurcating solutions is performed and the criteria for subcritical and supercritical Hopf bifurcation derived. The existence of a delay interval that preserves the stability of periodic orbits is demonstrated. The analysis emphasizes the importance of differential predation and a latency period in controlling disease dynamics.

A proportion of acute coronary syndromes (ACS) are thought to be triggered acutely by physical exertion, emotional stress and other stimuli. We assessed the consequences of triggering for long-term adaptation following ACS.We assessed mental and physical health status in 150 male and 44 female ACS survivors 12 and 36 months after cardiac events using standardised questionnaire measures. Triggers were assessed by interview an average of 2.56 days after hospital admission. Emotional triggers were defined as moderate or intense anger, stress or sadness/depressed mood in the 2 h before symptom onset, while vigorous physical exertion was defined as activity/=6 metabolic equivalents in the hour before symptom onset. Clinical characteristics, psychiatric history, health behaviours and the Global Registry of Acute Coronary Events (Grace) risk algorithm were also assessed.Emotional triggers predicted elevated anxiety and poor mental health status at 12 months independently of age, gender, socioeconomic status, ACS presentation, Grace risk scores, pre-admission medication, anxiety in hospital, depression history and symptom recurrence (p0.001). Effects persisted at 36 months. Emotional triggers were not related to physical health status at follow up. By contrast, impaired physical health status was predicted by vigorous exertion during the trigger period independently of covariates (p=0.019).ACS triggering has a long-term impact on adaptation and quality of life, with differential effects of physical and emotional triggers.

Objective: Evidence suggests that emotional stress can trigger acute coronary syndromes in patients with advanced coronary artery disease (CAD), although the mechanisms involved remain unclear. Hostility is associated with heightened reactivity to stress in healthy individuals, and with an elevated risk of adverse cardiac events in CAD patients. This study set out to test whether hostile individuals with advanced CAD were also more stress responsive. Methods: Thirty-four men (aged 55.9 +/- 9.3 years) who had recently survived an acute coronary syndrome took part in laboratory testing. Trait hostility was assessed by the Cook Medley Hostility Scale, and cardiovascular activity, salivary cortisol, and plasma concentrations of interleukin-6 were assessed at baseline, during performance of two mental tasks, and during a 2-h recovery. Results: Participants with higher hostility scores had heightened systolic and diastolic blood pressure (BP) reactivity to tasks (both P

The Bay of Bengal (BOB) sedimentary basin is one of the largest offshore sedimentary basins of the world having the thickest accumulation of sediments which mask the underlying crust and it is the Geopotential data that offers the unique opportunity of seeing below the thick sediments. Satellite derived Free Air Gravity (FAG) data, marine magnetic data, bathymetry, available seismic profiles and isopach maps over the Bay of Bengal are utilized in the present paper to throw light on the nature and tectonics of the BOB with particular emphasis on the 85°E Ridge. Combined analysis of gravity and magnetic data along six EW profiles of length varying from 325 to 440 km is undertaken, incorporating seafloor spreading anomalies in the model. Of the several theories put forth for the evolution of the 85°E Ridge, the present study supports the sagging of the crust and rules out the hotspot trace and magmatic under-plating theories. The crustal model derived from the magnetic profile analysis suggests that the 85°E Ridge does not extend to the North of 15°N latitude and this is supported by the Euler solutions of the FAG and the long wavelength filtered FAG. However, the intermediate wavelength filtered FAG suggests that the 85°E Ridge extends up to the Ocean Continent Boundary thereby suggesting that the 85°E Ridge thins out dramatically to the North of 15°N latitude. Analysis of gravity data along 17°N latitude profile predicts that in the northern segment the 85°E Ridge is a geo-morphological feature within the sediments above the basement whereas to the South of 15°N latitude it is a feature within the oceanic crust (below the basement). Further the reverse magnetization associated with the seafloor spreading anomalies lying on the 85°E Ridge belongs either to the Albian period or the anomaly A34/A33. The 85°E Ridge would be younger than these seafloor spreading anomalies and would have formed due to horizontal compressional forces of the lithosphere preceding development of the subduction zone at the Andaman trench.

Married individuals are at reduced risk of cardiovascular disease morbidity and mortality. Recent research indicates that impaired heart rate variability (HRV) may contribute to cardiovascular disease morbidity and mortality and has also been associated with social isolation.We investigated associations between HRV and marital status in patients with suspected coronary artery disease (CAD).Eighty-eight patients who were being investigated for suspected CAD (28 women, 60 men, mean age 61.6, 60% married) were recruited from three rapid access chest pain clinics in London. Heart rate variability was measured using 24-h electrocardiograms and analyzed using frequency and time-domain measures.Unmarried marital status was associated with reduced heart rate variability as indexed by both frequency and time-domain measures, independently of age, gender, beta-blocker use, depression ratings, and subsequent diagnosis of significant CAD.These findings suggest that reduced heart rate variability is associated with not being married and may contribute to the reliably observed relationship between marital status and cardiovascular disease morbidity and mortality.

The present paper deals with a detritus-based food-chain model within a mangrove ecosystem. The top predator (mainly fish) is assumed to have a commercial value and undergoes harvesting. Stability and bifurcation behavior of the model is studied and a threshold harvest rate is obtained. Next we introduce environmental nonhomogenity into the model equation. The resulting reaction diffusion system is investigated, and the criteria for supercritical Hopf bifurcation is obtained using the method of Lyapunov first coefficient. A comparison of the critical harvest rates under the homogeneous and the nonhomogeneous context is performed both analytically and numerically.

Ion beam sources for material processing in their working are no different from those required for space thrusters, ion implanters or for fusion experiments. They are scaled down versions of the devices earlier developed for space research. However, they are not being manufactured in the country. Their use in ophthalmic coatings and DLC for magnetic heads, CD, etc. are commercially attractive. In this technical report is suggested as to a strategy how to develop them, pooling resources from different active groups in the country, with specific targets. Dc gridded,Rf gridded, Saddle field, End Hall and ICP sources have been identified based on preliminary work carried out at different places in the country. This areas may be read more as a research opportunity report. Defence Science Journal, 2009, 59(4), pp.377-394 , DOI:http://dx.doi.org/10.14429/dsj.59.1537

A simple method is depicted in this communication to determine the optical constants of transparent thin films from transmittance versus wavelength traces, showing no fringes, for evaluating thickness. The strength of this technique is apparent when applied to Zn 1 − x Mg x O films.

Phase morphology of melt-mixed polypro- pylene (PP)/acrylonitrile-butadiene-styrene (ABS) blends was found to be blend ratio dependent, viz., matrix-parti- cle dispersed type of morphology which was observed up to 30 wt % of ABS level beyond which the morphology showed co-continuous type. The domain size of 80/20 PP/ABS blends was found to decrease significantly at 10 wt % carbon black (CB) level, and in case of 70/30 blends morphology was transformed into co-continuous type in the presence of CB, which was retained up to 60 wt % ABS. The finer morphological features were associated with the compatibilizing action of CB particles. Continu- ous network was achieved through aggregated CB par- ticles predominantly in the PP phase wherein one could find CB-rich PP phase and CB-less PP phase. Solution experiments further supported the existence of CB par- ticles preferentially in the PP phase. AC electrical conduc- tivity measurements indicated a 3D network-like structure of CB aggregates in the co-continuous compositions which showed enhanced electrical conductivity as compared to the matrix-dispersed type of morphology in 80/20 PP/ ABS blends which exhibited insulating behavior. On increasing ABS content in the blends the electrical conduc- tivity decreased progressively due to a difficulty in retain- ing 3D continuous network of CB aggregates especially at 40/60 composition. Increased processing temperature led to a higher electrical conductivity in the respective blends. Dielectric measurements revealed the existence of metallic type of conduction in the co-continuous compositions. However, 80/20 blends showed low e 0 value. Overall, structure property relationship studies were conducted in PP/ABS blends with CB. V C 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 998-1004, 2009

In the present paper we propose a modification of a basic eco-epidemiological model by incorporating predator switching among susceptible and infected prey population. A local and global study of the basic model is performed around the disease-free boundary equilibrium and the interior equilibrium to estimate important parameter thresholds that control disease eradication and species coexistence. Next we analyze the switching model from the same perspective in order to elucidate the role of switching on disease dynamics. Numerical simulations are carried out to justify analytical results.

Ongoing research on cancer has indicated that viruses which specifically infect and destroy tumor cells could be used as a therapeutic agent to arrest tumors. Some of these oncolytic viruses had already been tested clinically with success. However, the interaction dynamics between the tumor host, the invading virus and the immune system response is highly nonlinear and complex and, hence, a proper understanding of such dynamics requires involvement of mathematical models. In the present research, we consider a mathematical model of tumor-virus-immune system dynamics. We analyze the basic deterministic model to find out the importance of different host, viral and immune system parameters in controlling the system dynamics. Next we incorporate random noise inherent in any physiological process by extending the deterministic model into a stochastic one. The resulting stochastic model is studied using the mean square stability approach and criteria for stochastic stability is derived in terms of impo...

Multiwall carbon nanotubes (MWNT) were incorporated in melt-mixed co-continuous blends of polyamide 6 (PA6) and acrylonitrile–butadiene–styrene (ABS) using a conical twin-screw microcompounder. The state of dispersion of MWNT in the blends was assessed through AC electrical conductivity measurements and melt-rheological investigations. The electrical and rheological percolation threshold in PA6/ABS blends was ∼3–4 and ∼1–2 wt% MWNT, respectively. A unique reactive modifier (sodium salt of 6-amino hexanoic acid, Na–AHA) was employed to facilitate ‘network-like’ structure of MWNT and to confine them in a specific phase. This was achieved by establishing specific interactions with the delocalized ‘π-electron’ clouds of MWNT and melt-interfacial reaction during melt-mixing. The electrical percolation threshold was significantly reduced in the blends (∼0.25 wt%) in the presence of Na–AHA modified MWNT and even coincided with the rheological percolation threshold. Significant refinement in the co-continuous structure was also observed in the presence of Na–AHA modified MWNT.

In this paper, we apply an antiresonant reflecting layer concept in photonic crystal based waveguides. We have proposed a thin core ARRPCW with linear waveguide carved in it and hence calculated the transmission spectra for various length of waveguide and have shown that the longer waveguides in ARRPCW yields transmission with significantly high quality factor. Comparison of the transmission characteristics of normal conventional planar ARROW-B waveguides & ARRPCW has also been reported. The 2D FDTD numerical modeling reveals improved transmission for various lengths of planar ARROW and ARRPCW with low losses in long waveguides. Transmittance and quality factor are also calculated to confirm superior performance of the proposed design of ARROW based photonic crystal waveguide.

Ipomoea carnea Jacq. is a noxious aquatic weed with rapid vegetative growth and high invading powers. Infestation and population distribution of Aspidomorpha miliaris F. in Assam, India, showed that the beetle occurred on I. carnea at high densities (2.8–163.3 individuals/plant) causing damage up to 84%. Laboratory studies also support it as potential biocontrol agent for I. carnea.

Objective Poor social support is associated with recurrent cardiac events following acute coronary syndrome (ACS). Interventions have largely targeted emotional support, but practical support may be particularly important in encouraging recovery behaviors. We assessed whether practical and emotional support differentially predicted medication adherence and rehabilitation attendance following ACS. Methods This prospective observational clinical cohort study involved 262 survivors of verified ACS, recruited from four coronary care units in the London area. Practical and emotional support were measured in hospital, and depression, 7–10 days after discharge. Medication adherence and rehabilitation attendance were assessed by telephone interview 12 months after hospitalization. Results Nearly one third of patients (29.8%) had no practical supports, 16% had one, and 54.2% had two or more sources of practical support. Patients with greater practical support were more likely to adhere to medication ( P= .034) independently of age, gender, marital status, clinical risk profile, and depression. There was also an association with rehabilitation attendance ( P =.034), but this was no longer significant after depression had been taken into account. Emotional support was unrelated to medication adherence and rehabilitation attendance. Conclusions Cardiac patients with greater practical support may receive more prompts about medications, help with filling prescriptions and assistance with cardiac rehabilitation attendance. These behaviors can influence long-term recovery.

Objective To test associations between heart rate variability (HRV), depressed mood, and positive affect in patients with suspected coronary artery disease (CAD). Depression is associated with impaired HRV post acute cardiac events, but evidence in patients with stable coronary artery disease (CAD) is inconsistent. Methods Seventy-six patients (52 men, 24 women; mean age = 61.1 years) being investigated for suspected CAD on the basis of symptomatology and positive noninvasive tests, completed 24-hour electrocardiograms. The Beck Depression Inventory (BDI) was administered, and positive and depressed affect was measured over the study period with the Day Reconstruction Method (DRM). A total of 46 (60.5%) patients were later found to have definite CAD. HRV was analyzed, using spectral analysis. Results Typical diurnal profiles of HRV were observed, with greater normalized high frequency (HF) and lower normalized low frequency (LF) power in the night compared with the day. BDI depression scores were not consistently associated with HRV. But positive affect was associated with greater normalized HF power (p = .039) and reduced normalized LF power (p = .007) independently of age, gender, medication with beta blockers, CAD status, body mass index, smoking, and habitual physical activity level. In patients with definite CAD, depressed affect assessed using the DRM was associated with reduced normalized HF power and heightened normalized LF power (p = .007) independently of covariates. Conclusions Relationships between depression and HRV in patients with CAD may depend on affective experience over the monitoring period. Enhanced parasympathetic cardiac control may be a process through which positive affect protects against cardiovascular disease.

To assess the prevalence and predictors of posttraumatic stress symptoms in patients at 12 and 36 months post hospital admission for an acute coronary syndrome (ACS). There is increasing recognition that posttraumatic stress may develop in the aftermath of an acute cardiac event. However, there has been little research on the longer-term prevalence of posttraumatic stress disorder (PTSD).Posttraumatic stress symptoms were assessed at 12 months in 213 patients with ACS and in 179 patients at 36 months. Predictor variables included clinical, demographic, and emotional factors measured during hospital admission.At 12 months post ACS, 26 (12.2%) patients qualified for a diagnosis of PTSD; 23 (12.8%) patients were identified with PTSD at 36 months. Posttraumatic symptoms at 12 months were associated with younger age, ethnic minority status, social deprivation, cardiac symptom recurrence, history of depression, depressed mood during admission, hostility, and Type D personality. In multiple regression, depressed mood during admission and recurrent cardiac symptoms were independent predictors of posttraumatic symptoms (R(2) = 0.507, p.001). At 36 months, posttraumatic stress symptoms were independently predicted by posttraumatic symptom levels at 12 months and depressed mood during admission (R(2) = 0.635, p.001).Posttraumatic stress symptoms persist for at least 3 years after an acute cardiac event. Early emotional responses are important in predicting longer-term posttraumatic stress. It is important to identify patients at risk for posttraumatic stress as they are more likely to experience reduced quality of life.

Objective Depression is associated with coronary heart disease, but the underlying mechanisms are not fully understood. Cortisol is involved in the development of coronary artery disease (CAD), but evidence directly linking depression with cortisol in patients with CAD is limited. This study evaluated cortisol output over the day in patients with suspected CAD in relation to depressive symptoms. Methods Eighty-eight patients who were being investigated for suspected CAD (defined by clinical symptoms plus positive exercise tests or myocardial perfusion scans) took eight saliva samples over the day and evening. Depressed mood was assessed with the Beck Depression Inventory. Actigraphy was used to define time of waking objectively. Results The cortisol awakening response and cortisol rhythm over the remainder of the day and evening were analyzed separately. Fifty-two (61.9%) patients were later found to have definite CAD on angiography, while the remainder did not. The cortisol slope over the day was flatter in more depressed patients with CAD ( P P =.68). This effect was due to the combination of lower cortisol early in the day and higher cortisol in the evening in more depressed CAD patients, independent of age, gender, medication, and times of waking and sleeping ( P =.003). Additionally, cortisol measured on waking and 15 and 30 min after waking was greater in CAD than in non-CAD patients ( P =.04), but was not related to depression. Conclusions The flatter cortisol rhythms of more depressed CAD patients may contribute to the progression of coronary atherosclerosis.

In the present paper we study a three-component mathematical model of tumor–immune system interaction. A number of solid tumors contain a high proportion of macrophages and these immune cells are known to have a remarkable impact on the progression and dormancy of such tumors. We assume these macrophages as the main immune system component facilitating tumor destruction. Stability criteria of the basic model around the steady state of coexistence are derived. Next, we consider the process of macrophage activation as non-instantaneous by using a distributed delay with a weak kernel and obtain a range for the macrophage death rate that ensures system stability. Finally, we incorporate the spatial irregularity of solid tumors by making the delay nonlocal. Analysis of the resulting spatiotemporal model gives a number of thresholds in terms of different system parameters that guarantee tumor stability. Numerical simulations are performed to justify analytical findings.

Formations of Y and T nano junctions have been observed in boron nitride films deposited on silicon substrates by plasma chemical reaction of diborane (B2H6 diluted in hydrogen) and ammonia (NH3) gases using dual frequency (microwave/radio) plasma enhanced chemical vapor deposition technique without any intentional heating of the substrates. It has been observed that these nano junctions form at a critical feed gas ratio of ammonia and diborane. We have investigated the effect of gas feed ratio R (=NH3/B2H6) in the plasma reaction chamber, keeping all other deposition parameters constant, on the morphology of boron nitride films. The deposited films are characterized by SEM, AFM, TEM and Laser Raman. For gas feed ratio, R < 100, octahedron and cubic morphologies have been observed in BN films and on increasing R to > 100, size of the crystallites reduces to nanometer level. In some of our BN samples deposited at a critical value of gas ratio (R = 400), uniform Y and T junctions having bamboo like morphologies, in nanometer level, have been observed, which we wish to emphasis here as an interesting and newer observation in boron nitride films deposited by the dual frequency PECVD technique. This change in morphology exhibited by varying gas feed ratio is mainly due to excess nitrogen ions in the plasma.

We present a nonlinear SEIS epidemic model which incorporates distinct incidence rates for the exposed and the infected populations. The model is analyzed for stability and bifurcation behavior. To account for the realistic phenomenon of non-homogeneous mixing, the effect of diffusion on different population subclasses is considered. The diffusive model is analyzed using matrix stability theory and conditions for Turing bifurcation derived. Numerical simulations are performed to justify analytical findings.

Multiwall carbon nanotubes (MWNT) were melt-mixed with poly(ethylene-co-methacrylic acid) ionomers (Surlyn) using twin screw microcompounder. The specific interactions existing between the Na+ moieties in Surlyn and the pi electron clouds of MWNT were supported by FTIR and Raman spectroscopic analysis. SAXS scattering patterns were found to be progressively broadened in presence of MWNT in Surlyn/MWNT composites. Morphological investigations revealed selective clustering of MWNT in the vicinity of the ionic domains in Surlyn. Further, the domain size of the ionic clusters was found to increase with increasing MWNT content disrupting the ionic pairs apart in the ionic domain. The melt rheological response of Surlyn was significantly affected in presence of MWNT and was profoundly dependent on the ionic clusters. The state of dispersion of MWNT was assessed by AC electrical conductivity measurements. The associated percolation threshold was observed between 1.5-2 wt% of MWNT.

An efficient strategy to achieve electrical conductivity in melt-mixed co-continuous blends is to restrict the conducting filler in a particular phase in the blends next to forming a percolated 'network-like' structure in that particular phase. However, strong inter-tube van der Waals' forces often lead to the aggregated structure leading to higher percolation threshold. In addition, the migration of the conducting filler during melt-mixing and the blending sequence significantly affect the bulk conductivity of the blends. SEM observation showed fine co-continuous structures associated with 50/50 blends of PA6/Surlyn with multiwall carbon nanotubes (MWNT). MWNT were localized in the vicinity of the ionic domains in the ionomer corresponding to a specific blending sequence when unmodified MWNT were used, however, in presence of Na-salt of 6-amino hexanoic acid (Na-AHA) modified MWNT, selective clustering was not observed may be due to the confinement of MWNT in the PA6 phase. To understand these complexities the electrical conductivity of melt-mixed blends of polyamide6/ionomer with MWNT was studied. However, it was observed that the blends with even 3 wt% unmodified MWNT showed insulating behaviour irrespective of the blending sequence adopted. In addition, the key role of a reactive modifier (Na-AHA) in facilitating uniform dispersion and subsequent 'network-like' formation by establishing specific interactions with MWNT was studied. It was found that the MWNT are selectively localized in the PA6 phase in the NA-AHA modified blends manifesting in higher electrical conductivity (∼10 5 S/cm at 3 wt% MWNT) when using a specific blending sequence, due to melt-interfacial reaction between the ∼NH 2 functionality of Na-AHA and the ∼COOH end groups of PA6. FTIR and Raman spectroscopic analysis also supported the existence of the specific interactions.

Si-doped GaN films in polycrystalline form were deposited on quartz substrates at deposition temperatures ranging from 300–623 K using r.f. sputtering technique. Electrical, optical and microstructural properties were studied for these films. It was observed that films deposited at room temperature contained mainly hexagonal gallium nitride (h-GaN) while films deposited at 623 K were predominantly cubic (c-GaN) in nature. The films deposited at intermediate temperatures were found to contain both the hexagonal and cubic phases of GaN. Studies on the variation of conductivity with temperature indicated Mott’s hopping for films containing c-GaN while Efros and Shklovskii (E-S) hopping within the Coulomb gap was found to dominate the carrier transport mechanism in the films containing h-GaN. A crossover from Mott’s hopping to E-S hopping in the ‘soft’ Coulomb gap was noticed with lowering of temperature for films containing mixed phases of GaN. The relative intensity of the PL peak at ∼2·73 eV to that for peak at ∼3·11 eV appearing due to transitions from deep donor to valence band or shallow acceptors decreased significantly at higher temperature. Variation of band gap showed a bowing behaviour with the amount of cubic phase present in the films.

The application of a sufficiently high negative substrate bias, during the growth of tetrahedral amorphous carbon (ta-C), is usually associated with low sp3 bonding configuration and stressed films. However, in an effort to understand and utilize the higher pseudo thermo dynamical conditions during the film growth, at high negative substrate bias (− 300 V), reported here is a study on ta-C films grown under different hydrogen and nitrogen concentration. As grown ta-C films were studied under different negative substrate bias conditions. The variation of the sp3 content and sp3/sp2 ratio in the ta-C films exhibits a trend similar to those reported in literature, with a subtle variation in this report being the substrate bias voltage, which was observed to be around − 200 V, for obtaining the highest sp3 (80%) bonding and sp3/sp2 (3.95) ratio. The hydrogen and nitrogen incorporated ta-C films studied, at a bias of − 300 V, show an increase in sp3 (87–91%) bonding and sp3/sp2 (7–10) ratio in the range of studies reported. The inference is drawn on the basis of the set of data obtained from measurements carried out using X-ray photoelectron spectroscopy, X-ray induced Auger electron spectroscopy and Raman spectroscopy of as grown and hydrogen and nitrogen incorporated ta-C films deposited using an S bend filtered cathodic vacuum arc system. The study indicates the possibility of further tailoring ta-C film properties and also extending capabilities of the cathodic arc system for developing carbon based films for electronics and tribological applications.

Studies of the salivary cortisol awakening response (CAR) may be confounded by delays between waking in the morning and obtaining the 'waking' salivary sample. We used wrist actigraphy to provide objective information about waking time, and studied the influence of delays in taking the waking sample on the CAR. Eighty-three men and women (mean age 61.30 years) who were referred to hospital with suspected coronary artery disease were studied. Saliva samples were obtained on waking and 15 and 30 min later. The mean interval between waking defined by actigraphy and reported waking time was 6.12+/-(S.D.) 14.8 min, with 55.4% having no delay. The waking saliva sample was obtained an average 5.78+/-15.0 min after self-reported waking, and 12.24+/-20.3 min after objective waking. The waking cortisol value was significantly higher in participants who had a delay between waking and sampling >15 min (mean 14.46+/-6.34 nmol/l) than in those with zero (mean 10.45+/-6.41 nmol/l) or 1-15 min delays (mean 11.51+/-5.99 nmol/l, p=0.043). Cortisol did not increase between 15 and 30 min after waking in those who delayed >15 min. There were no differences in CAR between participants with zero and 1-15 min delays from objectively defined waking to reported sample times. A small proportion (14.7%) of participants who did not delay saliva sampling showed no increase in cortisol over the 30 min after waking. These CAR nonresponders did not differ from the remainder on sleep patterns, waking time, clinical or medication characteristics, but were more likely to be of higher socioeconomic status (p=0.009). We conclude that long delays between waking and obtaining 'waking' cortisol samples will lead to misleading CAR results, but that delays up to 15 min may not be problematic. A small minority of individuals do not show a positive CAR despite not delaying saliva sampling after waking.

The Carlsberg Ridge lies between the equator and the Owen fracture zone. It is the most prominent mid-ocean ridge segment of the western Indian Ocean, which contains a number of earthquake epicenters. Satellite altimetry can be used to infer subsurface geological structures analogous to gravity anomaly maps generated through ship-borne survey. In this study, free-air gravity and its 3D image have been generated over the Carlsberg Ridge using a very high resolution data base, as obtained from Geosat GM, ERS-1, Seasat and TOPEX/POSEIDON altimeter data. As observed in this study, the Carlsberg Ridge shows a slow spreading characteristic with a deep and wide graben (average width ∼15 km). The transform fault spacing confirms variable slow to intermediate characteristics with first and second order discontinuities. The isostatically compensated region of the Carlsberg Ridge could be demarcated with near zero contour values in the free-air gravity anomaly images over and along the Carlsberg Ridge axes and over most of the fracture zone patterns. Few profiles have been generated across the Carlsberg Ridge and the characteristics of slow/intermediate spreading ridge of various orders of discontinuity could be identified. It has also been observed in zero contour image as well as in the characteristics of valley patterns along the ridge from NW to SE that different spreading rates, from slow to intermediate, are occurring in different parts of the Carlsberg ridge. It maintains the morphology of a slow spreading ridge in the NW, where the wide and deep axial valley (∼1.5–3 km) also implies the pattern of a slow spreading ridge. However, a change in the morphology/depth of the axial valley from NW to SE indicates the nature of the Carlsberg Ridge as a slow to intermediate spreading ridge.

A three variable mathematical model describing the propagation of an infectious disease in a human population is proposed and analyzed. The human population is assumed to live in two distinct habitats with no inter-habitat migration. The infectious agent disperse randomly among the said habitats. Methods of upper and lower solutions are used to establish the existence of traveling wave solutions connecting the trivial with the nontrivial equilibrium. The critical wave speed required for the existence of such wave solutions has been found out and shown to depend on different system parameters together with the dispersal rate.

Blends of polyamide6 (PA6) and acrylonitrile butadiene styrene (ABS) were prepared in presence or absence of up to 5 wt % of a reactive compatibilizer [styrene maleic anhydride copolymer (SMA) modified with 5 wt % multiwall carbon nanotubes (MWNT)] by melt-mixing using conical twin screw microcompounder where the ABS content was varied from 20 to 50 wt %. The melt viscosity of the blends was significantly enhanced in presence of SMA modified by multiwall carbon nanotubes due to the reactive compatibilization, which leads to stabilized interphase in the blends. Furthermore, the presence of MWNT in the compatibilizer phase led to additional increase in viscosity and storage modulus. Morphological studies revealed the presence of either droplet-dispersed or cocontinuous type depending on the blend compositions. Further, reactive compatibilization led to a significant change in the morphology, namely a structure refining, which was enhanced by MWNT presence as observed from SEM micrographs. DSC crystallization studies indicated a delayed crystallization response of PA6 in presence of ABS presumably due to high melt viscosity of ABS. The crystallization temperature and the degree of crystallinity were strongly dependent on the type of morphology and content of reactive compatibilizer, whereas the presence of MWNT had an additional influence. SAXS studies revealed the formation of thinner and less perfect crystallites of PA6 phase in the blends, which showed cocontinuous morphology. A unique observation of multiple scattering maxima at higher q region has been found in the blends of cocontinuous morphology, which was observed to be successively broadened in presence of the compatibilizer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Wnt signaling follows canonical and non-canonical pathways to regulate a variety of processes during cellular homeostasis and development. The large T-antigen (T-Ag) of the human neurotropic JC virus, has been shown to modulate the Wnt-signaling pathway via interaction with beta-catenin, one of the most important components of the canonical Wnt pathway. Here, we have identified an alternative non-canonical pathway that allows T-Ag to recruit Rac1 for stabilizing beta-catenin by inhibiting its ubiquitin-dependent proteasomal degradation. We demonstrate that inhibition of Rac1 by its dominant negative mutant, RacN17, abrogates T-Ag-mediated stabilization of beta-catenin yet exhibits no impact on the transcriptional activity of beta-catenin. Results from immunocytochemistry revealed that together with T-Ag, a pool of beta-catenin appears at the cell surface, particularly at the membrane ruffles where active Rac1 is positioned. Interestingly, cooperativity between T-Ag and beta-catenin leads to activation of Rac1, which in turn, stimulates its association with beta-catenin. These observations unravel the interplay between beta-catenin and Rac1 that is initiated by T-Ag and results in stabilization of beta-catenin and its presence in cell membrane ruffles.

We have utilized satellite altimetry data to generate the very high-resolution gravity anomaly maps to infer subsurface geological structures in the area of the devastating earthquake (and the corresponding tsunami) that struck the Indian Ocean near Sumatra (Indonesia) on 26 December 2004. In the present study, a high-resolution three-dimensional (3D) gravity image has been generated over a part of the eastern Indian offshore encompassing the Sumatran earthquake region apart from Ninety East Ridge, Andaman subduction zone, etc. Four latitudinal (2°, 3°, 4° and 8.6° N) gravity profiles have been generated across the epicentre (3° N/M w 9.0)/aftershock regions (4° N/M w 5.8 and 8.6° N/M w 6.0 and 6.6). A drastic change of gravity anomaly patterns (∼130 mGal) near the epicentre and the aftershock regions could be observed, which are however slowly diminishing further away from the epicentre. This gravitational difference might have been caused by the differences in plate tectonic processes. Minor/major gravitational differences in other areas may be due to the changes in densities of different lithospheric zones/sedimentary layers. Hence, our study further supports the idea that negative gravity and topography anomalies can be used as a predictor for occurrences of large earthquakes in subduction zones.

We analyze a mathematical model of predator–prey interaction where the prey population is infected with a viral disease. Infection in the prey population is assumed to follow standard incidence. The dynamical behavior of the system is studied in terms of stability aspects. To model the gestation lag of the predator species and the spatially heterogeneous characteristics of an ecological population, we incorporate the concept of diffusionally coupled delay into the system. The bifurcation behavior of the delayed homogeneous system is studied. The existence of traveling wave solutions for the delay–diffusion model is established. Numerical simulations are performed to justify analytical findings.

ENVISAT AATSR data over the Indian subcontinent have been procured from ESA and preprocessed with DESCW and BEAM 2.2 software for extraction of our area of interest. Two intensive test sites have been chosen, including a part of the Himalayan region and the Sundarban Delta. Calibration of AATSR thermal IR data for surface temperature modelling has been attempted over the Sundarban Delta region. Later, the surface temperature maps have been utilized to generate the momentary and daily evapotranspiration patterns over the area of interest which have been further used for broad land use/crop classifications. A simplified model suggested by Soer [Estimation of regional evapotranspiration and soil moisture conditions using remotely sensed crop surface temperatures, Remote Sensing of Environment 9 (1980) 27–45] has been used to estimate evapotranspiration over the area of interest. The results match with the earlier observation in this region. Further processing of AATSR data has been performed over the Himalayan region to extract two minor faults across the main thrust belts.

Emotional triggers of acute coronary syndromes include population-level events such as earthquakes and terrorist attacks, and individual experiences of acute anger, stress and depression. The methodology of studying emotional triggers has developed markedly over recent years, though limitations remain. The biological processes underlying triggering include acute autonomic dysregulation, neuroendocrine activation, hemostatic and inflammatory responses which, when associated with plaque disruption, promote myocardial ischemia, cardiac dysrhythmia and thrombosis formation. Prevention and management strategies for ameliorating emotional triggering remain to be effectively developed.

We present and analyze a three-species mathematical model of tumor progression and regression using prey-predator dynamics. The tumor cell population is supposed to be the prey species and the cytotoxic T-lymphocytes (CTL) and macrophages (which are killer cells of the immune system) as their predator. Using a ratio-dependent predation functional form, the ODE model is analyzed for stability criteria. A discrete time delay required for destruction of tumor cells is then incorporated into the basic model and the resulting delayed model is studied to explore the significance of various system parameters controlling the stability of the system. The active killer cells are shown to be the key population species controlling the system dynamics. A range of the delay parameter is estimated that ensures stability of different system components. Numerical simulations are performed to support analytical findings.

The 20/80 blends of polyamide 6 (PA6) and acrylonitrile–butadiene–styrene copolymer (ABS) in the presence of styrene–maleic anhydride copolymer (SMA) and multiwall carbon nanotubes (MWNT) were prepared using melt-mixing technique. Crystallization behavior of the PA6 phase in the blends was studied using DSC, WAXD and SAXS techniques. Blends' morphology was characterized by SEM. We observed fractionated crystallization of PA6 phase in 20/80 PA6/ABS blends. It was also observed that the phenomenon of fractionated crystallization was influenced by the presence of both SMA and MWNT. Blends' morphology revealed the presence of wide domain size distribution of PA6 droplets in the amorphous ABS matrix. On incorporation of either SMA or SMA modified MWNT, the average domain size of PA6 droplets was found to be finer up to 1 wt% SMA modified MWNT. Encapsulation of SMA copolymer layer on the MWNT surface was also evident from SEM micrographs. SAXS analysis revealed the formation of multiple lamellae stacking of PA6 phase in the presence or absence of SMA and MWNT in 20/80 PA6/ABS blends. This was attributed to the formation of less perfect crystallites formed during the cooling of melt at higher degree of supercooling., © Elsevier

The present paper studies the naturally observed phenomenon of population fluctuation in the context of a minimal plankton model. The analysis of the basic model reveals asymptotic stable behavior that is unable to explain any kind of population outburst. We introduce the nonuniform spatial distribution of plankton by considering physical diffusion of the species concerned. The resulting reaction-diffusion equation model is first analyzed with constant diffusivity and then with variable diffusivity for the zooplankton. The model with variable diffusivity is analyzed by using Floquet theory. In both cases, the model is seen to exhibit stable behavior. Finally, we study another characteristic feature of any ecological population, namely, environmental fluctuations. We achieve this by perturbing the growth rate of phytoplankton and death rate of zooplankton by using colored noise. The resulting model is analyzed by evaluating the spectral density functions. It is observed that the stochastic model can generate a large fluctuation in population concentration for high amplitude driving forces.

Deposition of size-selected metal nanoclusters on a substrate with very low kinetic energy helps to keep the clusters intact with respect to their shapes and sizes as compared to clusters in flight condition. Here we report formation of monodispersed films of size-selected copper nanoclusters (diameter -3 nm) that are produced in a magnetron based gas aggregation type source equipped with a quardrupole mass filter (QMF) to select sizes of clusters before landing. Transmission Electron Microscopy (TEM) study shows that the size-distributions of isolated islands peaks around the selected size of clusters and consequently the diffusion of these nano-scale islands is very low.

Malaria is a major public health problem in north-east India mainly transmitted by Anopheles baimai and An. minimus while Anopheles nivipes plays an important supportive role. The genetic diversity of An. nivipes in north-east India was investigated by employing two mitochondrial DNA markers namely NADH dehydrogenase 5 (ND5) and cytochrome oxidase sub unit II (COII). High genetic diversity in An. nivipes was observed by the detection of 16 haplotypes among 30 sequences of ND5 gene and 29 haplotypes among 29 COII sequences. Anopheles nivipes of north-east India was significantly differentiated genetically with that of neighboring South-east Asian An. nivipes as revealed by pairwise FST values of 0.127 (p

Expanded graphite (EG) and multiwalled carbon nanotubes (MWNTs) based hybrid nano-composites were prepared with polyamide 6 (PA6) matrix via melt-mixing technique using a conical twin-screw micro-compounder. A novel organic modifier (lithium salt of 6-aminohexanoic acid; Li-AHA) was employed to modify MWNTs, which was utilized to intercalate Li-AHA modified MWNTs into the partially exfoliated EG gallery. Morphological investigation showed the intercalation of Li-AHA modified MWNTs into a partially exfoliated EG gallery in an EG/MWNTs-m2h hybrid, whereas the unmodified EG/MWNTs-h hybrid mixture exhibited a separate identity in the mixture. Improved interaction via melt-interfacial reaction between the acid end group of PA6 and the amine functionality of Li-AHA in the EG/MWNTs-m2h hybrid filler was confirmed by Fourier transform infrared spectroscopic analysis. The extent of melt-interfacial reaction was increased as a function of Li-AHA concentration in the filler. Wide angle X-ray diffraction analysis showed the existence of the alpha-crystalline phase of PA6. The incorporation of MWNTs, EG and EG/MWNTs hybrid in the PA6 matrix has favoured an alpha-crystalline structure of the PA6 phase. Crystallization studies have indicated a significant increase in the bulk crystallization temperature of the PA6 phase in the presence of MWNTs, EG and the EG/MWNTs hybrid filler. Moreover, the formation of PA6 'trans-crystalline lamellae' on the MWNTs surface was facilitated in the case of composites with MWNTs and the EG/MWNTs hybrid filler. An attempt has been made to investigate the role of the EG/MWNTs hybrid filler in influencing the crystallization behaviour of the PA6 phase in the hybrid nano-composites.

Strangelet Search at Mountain Altitude

Blends of polypropylene (PP) and polyamide 6 (PA6) with multiwalled carbon nanotubes (MWNTs) were prepared using different processing strategies in a twin-screw micro-compounder. The effect of MWNTs on the crystallization behaviour of the PP phase and the PA6 phase of the blend has been investigated through non-isothermal crystallization studies by differential scanning calorimetric analysis. Furthermore, the effect of the addition of the compatibilizer (PP-g-MA) and the modification of MWNTs (m-MWNTs) with a non-covalent organic modifier (Li-salt of 6 amino hexanoic acid, Li-AHA) has also been studied in context to the crystallization behaviour of the PP and PA6 phase in the blend. The crystallization studies have indicated a significant increase in bulk crystallization temperature of the PP phase in the blend in the presence of MWNTs. Moreover, the formation of 'trans-lamellar crystalline' structure consisting of PA6 'trans-crystalline lamellae' on MWNTs surface was facilitated in the case of blends prepared via 'protocol 2' as compared to the corresponding blends prepared via 'protocol 1'. Wide angle X-ray diffraction analysis has showed the existence of a beta-polymorph of the PP phase due to incorporation of the PA6 phase in the blend. Addition of MWNTs in the blends has facilitated further beta-crystalline structure formation of the PP phase. In the presence of m-MWNTs, a higher beta-fraction was observed in the PP phase as compared to the blend with pristine MWNTs. Addition of PP-g-MA has suppressed the beta-phase formation in the PP phase in the blend. X-ray bulk texture analysis revealed that incorporation of PA6 as well as pristine/modified MWNTs has influenced the extent of orientation of the PP chains towards specific crystalline planes in various blend compositions of PP and PA6.

SUBGROUP THEORETICAL PROPERTIES DETERMINING CLASSES OF GENERALIZED NILPOTENT GROUPS

This paper reports the fabrication of pentacene-based organic thin-film transistors using a dielectric material, Dynasylan (R) SIVO110. The devices exhibit excellent performance characterized by a low threshold voltage of -1.4V (operating voltage: 0 to -4V) together with a mobility of 1.9 cm(2) V(-1)s(-1). These results are promising because it uses only a single layer of dielectric without performing any intermediate treatment. The reason is attributed to the high charge storage capacity of the dielectric (kappa similar to 20.02), a low interfacial trap density (2.56 x 10(11) cm(-2)), and favorable pentacene film morphology consisting of large and interconnected grains having an average size of 234 nm. (C) 2015 AIP Publishing LLC.

The effect of simultaneous addition of multiwall carbon nanotubes (MWNTs) and a reactive compatibilizer (styrene maleic anhydride copolymer, SMA) during melt-mixing on the phase morphology of 80/20 (wt/wt) PA6/ABS blend has been investigated. Morphological analysis through scanning and transmission electron microscopic analysis revealed finer morphology of the blends in presence of SMA + MWNTs. Fourier transform infrared spectroscopic analysis indicated the formation of imide bonds during melt-mixing. Non-isothermal crystallization studies exhibited the presence of a majority faction of MWNTs in the PA6 phase of 80/20 (wt/wt) PA6/ABS blend in presence of SMA + MWNTs. Rheological analysis, dynamic mechanical thermal analysis, and thermogravimetric analysis have demonstrated the compatibilization action of simultaneous addition of a reactive compatibilizer (SMA copolymer) and MWNTs in PA6/ABS blends. An attempt has been made to investigate the role of simultaneous addition of SMA copolymer and MWNTs on the morphology of 80/20 (wt/wt) PA6/ABS blend through various characterization techniques. POLYM. ENG. SCI., 55:457-465, 2015. (c) 2014 Society of Plastics Engineers

A STATISTICALLY DISTRIBUTED RANDOM BINARY IMAGE GENERATOR

Versatility of cold plasma processing has made its deployment in numerous fields possible and is now seen as a vehicle for creation of wealth. In this paper we show how it has been successfully used in high rate deposition of device quality amorphous Hydrogenated Silicon thin films, stress relived Diamond Like Carbon (DLC) films, as also in growingGem quality diamondfilms

The effect of multiwall carbon nanotubes (MWNTs) on the bulk electrical conductivity and phase morphology of melt-mixed blends of polyamide 6 (PA6)/acrylonitrile-butadiene-styrene copolymer (ABS) has been investigated in this work. The bulk electrical conductivity of the blends with MWNTs was strongly dependent on the selective localization of MWNTs in the PA6 phase of the blends. Further, the selective localization of MWNTs in the PA6 phase led to a significant change in the phase morphology. The dual phase continuity was broader over a much larger composition range in the presence of MWNTs. In order to facilitate 3D “network-like” structure of MWNTs in the blends, a unique reactive modifier has been utilized. Significant changes in both bulk electrical conductivity and phase morphology have been found in the presence of modified MWNTs in the blends. An attempt has been made to understand the varying electrical conductivity in these blends through the alteration of phase morphology along with “aggregated” versus “uniform” dispersion of MWNTs in unmodified and modified MWNTs-based blends.

This paper presents the X-ray absorption near edge structure (XANES) studies of Nd doped phosphate glasses before and after gamma irradiation. The intensity and location of LIII edge white line peak of Nd changes depending on its concentration as well as on the ratio of O/Nd in the glass matrix. The decrease in the peak intensity of white line after gamma irradiation indicates towards reduction of Nd3+ to Nd2+ in the glass matrix, which increases with an increase in the doses of gamma irradiation. Similarity in the XANES spectra of Nd doped phosphate glasses and Nd2O3 suggests that coordination geometry around Nd3+ in glass samples may be identical to that of Nd2O3.