We report the results of Long Baseline Array observations made in 2001 of ten southern sources proposed by Mattox et al. as counterparts to EGRET >100 MeV gamma-ray sources. Source structures are compared with published data where available and possible superluminal motions identified in several cases. The associations are examined in the light of Fermi observations, indicating that the confirmed counterparts tend to have radio properties consistent with other identifications, including flat radio spectral index, high brightness temperature, greater radio variability, and higher core dominance.

We present results from a multiwavelength study of the blazar PKS 1954–388 at radio, UV, X-ray, and gamma-ray energies. A RadioAstron observation at 1.66 GHz in June 2012 resulted in the detection of interferometric fringes on baselines of 6.2 Earth-diameters. This suggests a source frame brightness temperature of greater than 2 × 1012 K, well in excess of both equipartition and inverse Compton limits and implying the existence of Doppler boosting in the core. An 8.4-GHz TANAMI VLBI image, made less than a month after the RadioAstron observations, is consistent with a previously reported superluminal motion for a jet component. Flux density monitoring with the Australia Telescope Compact Array confirms previous evidence for long-term variability that increases with observing frequency. A search for more rapid variability revealed no evidence for significant day-scale flux density variation. The ATCA light-curve reveals a strong radio flare beginning in late 2013, which peaks higher, and earlier, at higher frequencies. Comparison with the Fermi gamma-ray light-curve indicates this followed ~ 9 months after the start of a prolonged gamma-ray high-state—a radio lag comparable to that seen in other blazars. The multiwavelength data are combined to derive a Spectral Energy Distribution, which is fitted by a one-zone synchrotron-self-Compton (SSC) model with the addition of external Compton (EC) emission.

The preliminary design phase of an aircraft requires quick calculation methods to assess its performance. This note develops an analytical method to obtain the optimum range and associated flight parameters for a piston-prop aircraft. The aircraft is flying so that the altitude and airspeed are kept constant.

Such a flight is called “constant altitude-constant airspeed” flight or simply “constant h-V flight”. Transport aircraft generally utilise this type of flight profile. Such a profile has been analysed by Bert for turbojet aircraft, and Hale has discussed it for both turbojet and piston-prop aircraft. This note further improves the analysis of constant h-V flight by optimising it independently and without using the known values from any other flight profile.

Little information is available about perceptions of influenza vaccination of parents with healthy children in daycare. Therefore, we systematically explored the relationship between parental risk perception and influenza vaccination in children attending daycare. We distributed a self-administered paper survey to parents of children aged 6–59 months attending licensed daycare centres in Tarrant County, Texas. We used conditional logistic regression with penalized conditional likelihood to estimate odds ratios (ORs) and 95% profile likelihood confidence limits (PL) for parental risk-perception factors and influenza vaccination. A high level of parental prevention behaviours (OR 9·1, 95% PL 3·2, 31) and physician recommendation (OR 8·2, 95% PL 2·7, 30) had the highest magnitudes of association with influenza vaccination of healthy children in daycare. Our results provide evidence about critical determinants of influenza vaccination of healthy children in daycare, which could help inform public health interventions aimed at increasing influenza vaccination coverage in this population.

The landraces of rice (Oryza sativa L.) possess wide diversity, which needs to be properly characterized for their use in genetic improvement. Replicated field studies were conducted in 1998, 1999 and 2000 at two sites in Nepal to determine diversity in 183 landraces of rice adapted to the lowlands and the hills in Nepal. Fourteen improved genotypes were also used for comparison. Thirteen agronomic traits were investigated. Shannon–Weaver diversity index (H) and Simpson's index of diversity (D) were estimated to determine the level of genetic richness among the landraces. The landraces differed significantly for all traits. Except for plant height and maturity, at least one of the landraces compared well with the performance of improved cultivars. A principal component analysis separated the lowland- and hill-adapted landraces into two broad groups.

We have carried out a multi-wavelength study of the star forming region NGC 1893 to make a comprehensive exploration of the effects of massive stars on low mass star formation. Using deep optical U BV RI broad band, Hα narrow band photometry and slit-less spectroscopy along with archival data from the surveys such as 2MASS, MSX, IRAS and NVSS, we have studied the region to understand the star formation scenario in the region.

A photochromic tracer method has been used to record pulsatile flow velocity profiles simultaneously at three axial locations along a flow channel. Two major advantages of this multiple-trace method are that it enables velocity data to be acquired in an efficient non-invasive manner and that it provides a detailed description of the spatial relationship of the flow field. The latter is found to be particularly useful in the investigation of transitional type flows; for example, in describing coherent flow structures. Studies of the flow patterns in tubes with mild to moderate degrees of vessel constriction were performed using a 2.9 Hz sinusoidal flow superimposed on a steady flow (frequency parameter of 7.5; mean and modulation Reynolds numbers of 575 and 360, respectively). With mild constrictions (< 50% area reduction), isolated regions of vortical and helical structures were observed primarily during the deceleration phase of the flow cycle and in the vicinity of the reattachment point. As expected, these effects were accentuated when the constriction was asymmetric. For moderate constrictions (50%–80%), transition to turbulence was triggered just before peak flow through the breakdown of waves and streamwise vortices that were shed in the high-shear layer. During this vortex generation phase of the flow cycle, the wall shear stress fluctuated quite intensely, especially in the vicinity of the reattachment point, and its instantaneous value increased by at least a factor of eight. Such detailed descriptions of the transition to turbulence and of the spatial and temporal variation of the wall shear stress, particularly near the reattachment point, have not been previously reported for pulsatile flow through constricted tubes. The observed wall shear stress variations support a proposal by Mao & Hanratty (1986) of an interaction of the imposed flow oscillation with the turbulent fluctuations within the viscous sublayer.

We consider here the higher order effect of moderate longitudinal surface curvature on steady, two-dimensional, incompressible laminar boundary layers. The basic partial differential equations for the problem, derived by the method of matched asymptotic expansions, are found to possess similarity solutions for a family of surface curvatures and pressure gradients. The similarity equations obtained by this anaylsis have been solved numerically on a computer, and show a definite decrease in skin friction when the surface has convex curvature in all cases including zero pressure gradient. Typical velocity profiles and some relevant boundary-layer characteristics are tabulated, and a critical comparison with previous work is given.

Large scale (~0.6 sq deg) mapping of the giant Galactic star forming complex W 51 has been carried out simultaneously in two trans-IRAS far infrared (FIR) bands centered at ~200 and 130 μm using the TIFR 100 cm balloon borne FIR telescope. The choice of the bands is motivated by the aim of studying the emission from the cold dust (T < 30 K) component.These maps with ~1' spatial resolution, show extended emission with structures. Nearly identical beams in the two bands have enabled us to reliably determine the distribution of dust temperature T(130/200), and opticaldepth τ200, in the central region of the W 51 complex. A total of 25 discrete sources have been extracted from the 200 μmmap, of which 8 have been associated with IRAS PSC sources and 16 with sources in HIRES processed IRAS maps at 100, 60, 25 & 12 μmbands.The values of the emissivity power law index β in FIR, show wide variation among these sources.

The on-farm performance of more than 150 000 pre-basic potato (Solanum tuberosum) minitubers of 1–10 g was monitored over two years in contrasting environments in Nepal. Average minituber productivity (grams of basic seed produced per minituber planted) was 171 g in the southern plains and 116 g in the hills. Although the performance of minitubers varied between environments, minituber sizes and potato varieties, the overall results clearly indicated that minitubers can be successfully multiplied by small-scale farmers. This technology therefore allows for the highly decentralized production of basic seed which, in turn, will reduce farmers' dependence on an unreliable and costly supply of bulky conventional seed.