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Context.PKS 1749+096 is a BL Lac object showing weak extended jet emission to the northeast of the compact VLBI core on parsec scales. Aims. We aim at better understanding the jet kinematics and variability of this source and finding clues that may applicable to other BL Lac objects. Methods. The jet was studied with multi-epoch multi-frequency high-resolution VLBI observations. Results. The jet is characterized by a one-sided curved morphology at all epochs and all frequencies. The VLBI core, located at the southern end of the jet, was identified based on its spectral properties. The equipartition magnetic field of the core was investigated, through which we derived a Doppler factor of 5, largely consistent with that derived from kinematics (component C5). The study of the detailed jet kinematics at 22 and 15 GHz, spanning a period of more than 10 years, indicates the possible existence of a bimodal distribution of the jet apparent speed. Ballistic and non-ballistic components are found to coexist in the jet. Superluminal motions in the range of 5-21?c were measured in 11 distinct components. We estimated the physical jet parameters with the minimum Lorentz factor of 10.2 and Doppler factors in the range of 10.2-20.4 (component C5). The coincidence in time of the component's ejection and flares supports the idea that, at least in PKS 1749+096, ejection of new jet components is connected with major outbursts in flux density. For the best-traced component (C5) we found that the flux density decays rapidly as it travels downstream the jet, accompanied by a steepening of its spectra, which argues in favor of a contribution of inverse Compton cooling. These properties make PKS 1749+096 a suitable target for an intensive monitoring to decipher the variability phenomenon of BL Lac objects. [ABSTRACT FROM AUTHOR]

We report on Very Long Baseline Array polarimetric observations of NRAO 530 at 5, 8, 15, 22 and 43 GHz made during one week in 1997 February. We present the total intensity, the fractional polarization and the electric vector position angle (EVPA) distributions at all these frequencies. A model fitting has been performed to the full polarization visibility data. From this, the fitted southernmost component A is confirmed as the core of the radio structure with relatively high brightness temperature and hard spectrum between 15 and 43 GHz in comparison with the central component B of dominant flux. The relatively high degree of polarization for the component A may arise from its complex radio structure, which can be resolved at 86 GHz. In contrast, the component B shows a well-fitted power-law spectrum with a spectral index of about −0.5 ( ), and a linear correlation between EVPAs and wavelength square with an observed rotation measure of about −1062 rad m−2, indicating its structural singleness. Assuming that the component B has a comparable degree of polarization without depolarization at these frequencies, the decrease in fractional polarization with wavelength mainly results from opacity and Faraday rotation, in which the opacity plays quite a large role. A spine-sheath-like structure in fractional polarization ( m) is detected, covering almost the whole emission region at 5 and 8 GHz, with a degree of polarization relatively low along the jet spine, becoming higher towards two sides of the jet. The linear polarization at 5 GHz shows three separate polarized emission regions with alternately aligned and orthogonal polarization vectors down the jet. The polarization goes to zero between the top two regions, with the highest polarization level occurring at the top and bottom. The 5- and 8-GHz images show EVPA changes across the width of the jet as well as along the jet. These complex polarimetric properties can be explained in terms of either the presence of a large helical magnetic field or tangled magnetic fields compressed and sheared down the jet. These can be further determined by multifrequency polarimetric very long baseline interferometry observations with sufficient high resolution and sensitivity spanning an appropriate frequency range. [ABSTRACT FROM AUTHOR]

We report the proper motions of SiO maser features around VX Sgr from the two-epoch VLBA observations (2006 December 15 and 2007 August 19). The majority of maser feature activities show a trend of outward motions. It is consistent with our previous finding that the outflow may play an important role for SiO maser pumping. [ABSTRACT FROM AUTHOR]

We searched for the γ-ray signal from M33, one of the largest galaxies in the Local Group, using the Pass8 data from the Fermi Large Area Telescope (LAT). No statistically significant γ-ray emission has been detected in the direction of M33, and we report a new upper limit of the high-energy (>100 MeV) photon flux of 2.3 × 10-9 ph cm-2 s-1, which is stricter than previous constraints and implies a cosmic ray density for M33 that is lower than that suggested previously. The current limit is still, however, in agreement with the correlation of star formation rate and γ-ray luminosity inferred from the Local group galaxies and a few nearby starburst galaxies. [ABSTRACT FROM AUTHOR]

VX Sgr is a red supergiant at an adopted distance of 1.6 kpc with intense 43 GHz SiO maser emission. In this paper, we present the high-resolution very long baseline interferometry (VLBI) observations of SiO masers toward VX Sgr at five epochs. We used the Very Long Baseline Array to map the J = 1→0 (v = 1, 2) 28SiO masers and confirmed a ring-like structure. In the first two epochs, the v = 1 masers form a ring, but v = 2 maser spots residing only in the southern and northern regions do not form a complete ring. In the third epoch, the two masers are distributed in a ring structure and the v = 2 masers are a bit closer to the central star. In the last two epochs, many new maser spots appear and overlap each other. These overlapping maser spots can be related to the shock waves and reflect the collisional pumping. We compare the observations with the pumping models and speculate that the real pumping mechanism may be complex in VX Sgr and vary with time. The J = 1→0 (v = 0) 29SiO line emission is also detected, but is too weak to produce any VLBI map. [ABSTRACT FROM AUTHOR]

We report multi-frequency VLBA phase-referencing observation results of 3C 66A and 3C 66B, including high resolution maps and relative position measurements. The resulting images show similar morphology with that presented in previous works. We find core shift variations in both sources, indicating some physical condition changes in the jets. [ABSTRACT FROM AUTHOR]

Europium doped CaAl2O4 nanocones have been grown first time by thermal evaporation method. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to analyze the morphology, size and crystal structure of the nanocones. The body of the nanocones are about 2–20 μm in length and their diameters are 200 nm to 1 μm at one end and tapers off to a ~ 40–200 nm at the tip end. The as-synthesized nanocones are single crystalline in monoclinic structure and grow along the [010] direction and the normal direction of (100) and (001). The room temperature photoluminescence (PL) and cathodoluminescence (CL) spectrum measurement reveals that CaAl2O4:Eu2+ nanocones emit light at about 440 nm. [ABSTRACT FROM AUTHOR]

ABSTRACT We investigate the total flux density, spectral, polarization and Faraday rotation variability of HST-1 in the M87 jet during the outburst from 2003 to 2007 through multi-epoch Very Large Array observations at 8, 15 and 22 GHz. Contrary to the general case for blazars, the flux densities of HST-1 rise earlier at lower frequencies from radio to X-ray, and the spectra are softening with the growth of outburst, indicating that the newly emerging subcomponents within HST-1 have relatively steep spectra. In particular, the intrinsic optical electric vector positional angle varies monotonically by ∼90° at the three wavebands during the period, and all but the stationary subcomponent in the eastern end of HST-1 move downstream superluminally deviating divergently from the overall jet direction, with the motion of the outmost subcomponent bending from one side of the jet axis to another. These strongly argue for the presence of helical magnetic fields around HST-1, which is also supported by the fact that the subcomponents might be accelerated in this region. The fractional polarization is relatively low in the rising stage, and in the decaying stage the polarization levels are almost comparable at the three wavebands. In view of the quite large rotation measure (RM) values, Faraday rotation is expected to occur dominantly external to HST-1 in the decaying stage, which is well supported by the presence of diffuse emission around HST-1, and consistent with the scenario that RM decrease gets slower with time. [ABSTRACT FROM AUTHOR]

We report on VLA observations of HST-1 in M87 at 8 GHz from 2003-2007, during which a long major outburst occurs from radio to X-ray wave bands. At the VLA resolution, the flux density of HST-1 rises rapidly from 2003, peaks at the end of 2004, and then falls slowly in subsequent stages, which is similar to that in optical and X-ray wave bands. It appears that HST-1 moves with an apparent speed of 1.23 c±0.91 c, and the fractional polarization keeps rising through the whole major outburst. The persistent increase in polarization level may mainly be attributed to the formation of a couple of new 'subcomponents' of relatively high degree of polarization within HST-1, and the weakening depolarization due to Faraday rotation and/or opacity through the whole major outburst. [ABSTRACT FROM AUTHOR]

Simultaneous second-harmonic generation and electric-optic coupling in a periodic or quasi-periodic optical superlattice has been demonstrated experimentally. The output of the second harmonic can be controlled by the DC electric field or the temperature. The results offer us a way to manipulate the nonlinear interactions. [ABSTRACT FROM AUTHOR]

We have compared the results of a number of published class I methanol maser surveys with the catalogue of high-mass outflow candidates identified from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire survey (known as extended green objects or EGOs). We find class I methanol masers associated with approximately two-thirds of EGOs. Although the association between outflows and class I methanol masers has long been postulated on the basis of detailed studies of a small number of sources, this result demonstrates the relationship for the first time on a statistical basis. Despite the publication of a number of searches for class I methanol masers, a close physical association with another astrophysical object which could be targeted for the search is still lacking. The close association between class I methanol masers and EGOs therefore provides a large catalogue of candidate sources, most of which have not previously been searched for class I methanol masers. Interstellar masers and outflows have both been proposed to trace an evolutionary sequence for high-mass star formation, therefore a better understanding of the relationship between class I methanol masers and outflow offers the potential for comparison and amalgamation of these two evolutionary sequences. [ABSTRACT FROM AUTHOR]

We report on the detection of 146 (0.96%) bright pulses with a peak flux density >0.86 Jy from PSR B0031–07 in 4 hr of continuous observations made at 4.82 GHz, with a bandwidth of 1 GHz, using the Shanghai Tian Ma 65 m radio telescope. We find that the peak flux density distribution follows a power law with index α = −3.6 ± 0.2, while the pulse energy appears to follow a logarithmic normal distribution. The bright pulses from PSR B0031–07 were observed to repeat in an irregular fashion. The intervals between bright pulses can be described with an exponentiated Weibull distribution. Furthermore, the sensitive observations at higher frequency with a short time resolution of 65.54 μs form a reliable basis for detailed microstructure studies. Close inspection of the detected bright pulses reveals that 38 pulses exhibit well-defined quasi-periodicities. No unanimous period for the quasi-periodicities is found, and the peak flux density is independent of the micropulse width. Finally, possible physical mechanisms are discussed. [ABSTRACT FROM AUTHOR]

We searched for shocked carbon chain chemistry (SCCC) sources with C3S abundances surpassing those of HC5N toward the dark cloud L1251, using the Effelsberg telescope at the K band (18–26 GHz). L1251-1 and L1251-3 are identified as the most promising SCCC sources. The two sources harbor young stellar objects. We conducted mapping observations toward L1251-A, the western tail of L1251, at λ ∼ 3 mm with the Purple Mountain Observatory 13.7 m and the Nobeyama Radio Observatory 45 m telescopes in lines of C2H, N2H+, CS, HCO+, SO, HC3N, and C18O as well as in CO 3–2 using the James Clerk Maxwell Telescope (JCMT). The spectral data were combined with archival data including Spitzer and Herschel continuum maps for further analysis. Filamentary substructures labeled as F1–F6 were extracted in L1251, with F1 being associated with L1251-A hosting L1251-1. The peak positions of dense gas traced by HCO+ are misaligned relative to those of the dust clumps. Episodic outflows are common in this region. The twisted morphology of F1 and velocity distribution along L1251-A may originate from stellar feedback. SCCC in L1251-1 may have been caused by outflow activities originated from the infrared source IRS1. The signposts of ongoing SCCC and the broadened line widths of C3S and C4H in L1251-1 as well as the distribution of HC3N are also related to outflow activities in this region. L1251-1 (IRS1) together with the previously identified SCCC source IRS3 demonstrate that L1251-A is an excellent region to study SCCC. [ABSTRACT FROM AUTHOR]

Fat-tailed sheep ( Ovis aries) can survive in harsh environments and satisfy human's intake of dietary fat. However, the animals require more feed, which increases the cost of farming. Thus, most farmers currently prefer thin-tailed, short-tailed or docked sheep. To date, the molecular mechanism of the formation of fat tails in sheep has not been completely elucidated. Here, we conducted a genome-wide association study using phenotypes and genotypes (the Ovine Infinium HD SNP BeadChip genotype data) of two breeds of contrasting tail types (78 Small-tailed and 78 Large-tailed Han sheep breeds) to identify functional genes and variants associated with fat deposition. We identified four significantly (rs416433540, rs409848439, rs408118325 and rs402128848) and three approximately associated autosomal SNPs (rs401248376, rs402445895 and rs416201901). Gene annotation indicated that the surrounding genes ( CREB1, STEAP4, CTBP1 and RIP140, also known as NRIP1) function in lipid storage or fat cell regulation. Furthermore, through an X-chromosome-wide association analysis, we detected significantly associated SNPs in the OARX: 88-89 Mb region, which could be a strong candidate genomic region for fat deposition in tails of sheep. Our results represent a new genomic resource for sheep genetics and breeding. In addition, the findings provide novel insights into genetic mechanisms of fat deposition in the tail of sheep and other mammals. [ABSTRACT FROM AUTHOR]

Genome-wide association studies ( GWASs) have been widely applied in livestock to identify genes associated with traits of economic interest. Here, we conducted the first GWAS of the supernumerary nipple phenotype in Wadi sheep, a native Chinese sheep breed, based on Ovine Infinium HD SNP BeadChip genotypes in a total of 144 ewes (75 cases with four teats, including two normal and two supernumerary teats, and 69 control cases with two teats). We detected 63 significant SNPs at the chromosome-wise threshold. Additionally, one candidate region (chr1: 170.723-170.734 Mb) was identified by haplotype-based association tests, with one SNP (rs413490006) surrounding functional genes BBX and CD47 on chromosome 1 being commonly identified as significant by the two mentioned analyses. Moreover, Gene Ontology enrichment for the significant SNPs identified by the GWAS analysis was functionally clustered into the categories of receptor activity and synaptic membrane. In addition, pathway mapping revealed four promising pathways (Wnt, oxytocin, MAPK and axon guidance) involved in the development of the supernumerary nipple phenotype. Our results provide novel and important insights into the genetic mechanisms underlying the phenotype of supernumerary nipples in mammals, including humans. These findings may be useful for future breeding and genetics in sheep and other livestock. [ABSTRACT FROM AUTHOR]

We establish a simple model to describe the helical magnetic fields in AGN jets projected on the sky plane and the line-of-sight. This kind of profile has been detected in the polarimetric VLBI observation of many blazar objects, suggesting the existence of helical magnetic fields in these sources. [ABSTRACT FROM AUTHOR]

Reproductive diseases have been a great threat in large animal herds. Before induction of western medicines, traditional Chinese medicine (TCM) that is based on the use of herbal medicine, acupuncture, massage and other forms of therapy has been practiced in China for thousands of years. The foundational text of Chinese medicine dated back to 5th century to 3rd century BCE, humans in China began developing the TCM therapy by maintaining normal homeostasis and body functions. Traditional Chinese medicine prophylaxis is a very different strategy from that of the western medicine, targeting the balance of the diseased animals as compared to the single lesion. Traditional Chinese medicine was also applied to cure ruminant's reproductive disorders such as infertility, abortion and retained placenta. With the increasing concerns of the antibiotic resistance and drug abuse happened, TCM has acquired re-recognition as compared to western medicines due to eco-friendly consumer-driven developments and less residue in food chains. More importantly, a growing number of active substances or extracts with the reliable efficacy are being identified, meanwhile, the quality control measures are satisfied in the large-scale production already. However, few TCM is recognized to be used internationally as the popular human medication. Even less TCM is prescribed legally to animal industry due to poor understanding TCM philosophy and lack of the right guidelines of the registration. This summary aims to elucidate the TCM application in the treatment of the reproductive disorder in large animals and offer alternative strategies for prophylaxis. [ABSTRACT FROM AUTHOR]

Previous observations have shown that the distribution of 36.2-GHz class I methanol megamaser (MM) emission in Arp 220 is highly correlated with the diffuse X-rays. On this basis it was suggested that methanol MM may be produced either by the effects of galactic-outflowdriven shocks and/or cosmic rays. Here we report the results of a single-dish survey undertaken with the Greenbank Telescope (GBT) to improve our understanding of the pumping conditions of extragalactic class I methanol masers and their relationship to starburst and feedback processes within the host galaxies, towards a sample which includes 16 galaxies which show both extended soft X-ray emission, and either OH or H2O MM emission. Large baseline ripples in the GBT spectra limited our results to tentative detections towards 11 of the target galaxies. Analysis of these tentative detections shows that there are significant correlations between the methanol intensity and the host-galaxy infrared, radio and OH MM emission, but no correlation with the X-ray and H2O MM emission. Some sources show methanol emission significantly offset from the systemic velocity of the galaxy (by up to 1000 km s-1) and we propose that these are associated with galactic-scale outflows from active galactic nuclei (AGNs) feedback. The combined observational properties suggest that class I methanol MMs are related to significant starburst and molecular outflow activity and hence may provide a potential probe of AGN feedback and starburst processes in the host galaxies. [ABSTRACT FROM AUTHOR]

The sip gene encoding for a conserved highly immunogenic surface protein of Streptococcus agalactiae was amplified using polymerase chain reaction (PCR) and subcloned into prokaryotic expression vector pET32a (+) and expressed as a recombinant protein in E. coli BL21 (DE3). An indirect enzyme linked immunosorbent assay (ELISA) was developed using the purified Sip protein as a coating antigen, which could identify S. agalactiae specific antibody in sera. The coating antigen at a concentration of 3.125 μg/ml, serum diluted to 1:160, and HRP-conjugated secondary antibody concentration at 1:4000 was found to be most effective in exhibiting positive result. The ELISA was found to be highly specific for S. agalactiae that may be used for the detection of the pathogen in mastitis cases, for epidemiological studies and for surveillance. [ABSTRACT FROM AUTHOR]

We have precisely measured reaction cross sections (R) for 8Li using 9Be, 12C, 27Al, and proton targets at intermediate energies by the transmission method. From the energy dependence of the R including the high energy data, the density distribution of 8Li was deduced through a modified Glauber model. It is shown that 8Li has a shorter tail structure in the density as compared with that of 8B and the matter radius of 8Li is similar to those of the other nonhalo Li isotopes. The result is consistent with the previous experiments that there is a tendency for 8Li to be a skin nucleus. [ABSTRACT FROM AUTHOR]

We present results on the compact steep-spectrum quasar 3C 48 from observations with the Very Long Baseline Array (VLBA), the Multi-Element Radio Linked Interferometer Network (MERLIN) and the European Very long baseline interferometry (VLBI) Network (EVN) at multiple radio frequencies. In the 1.5-GHz VLBI images, the radio jet is characterized by a series of bright knots. The active nucleus is embedded in the southernmost VLBI component A, which is further resolved into two sub-components A1 and A2 at 4.8 and 8.3 GHz, respectively. A1 shows a flat spectrum and A2 shows a steep spectrum. The most strongly polarized VLBI components are located at component C ∼ 0.25 arcsec north of the core, where the jet starts to bend to the north-east. The polarization angles at C show gradual changes across the jet width at all observed frequencies, indicative of a gradient in the emission-weighted intrinsic polarization angle across the jet and possibly a systematic gradient in the rotation measure; moreover, the percentage of polarization increases near the curvature at C, likely consistent with the presence of a local jet–interstellar-medium interaction and/or changing magnetic-field directions. The hot spot B shows a higher rotation measure, and has no detected proper motion. These facts provide some evidence for a stationary shock in the vicinity of B. Comparison of the present VLBI observations with those made 8.43 yr ago suggests a significant northward motion for A2 with an apparent transverse velocity . The apparent superluminal motion suggests that the relativistic jet plasma moves at a velocity of if the jet is viewed at an inclination angle less than . A simple precessing jet model and a hydrodynamical isothermal jet model with helical-mode Kelvin–Helmholtz instabilities are used to fit the oscillatory jet trajectory of 3C 48 defined by the bright knots. [ABSTRACT FROM AUTHOR]