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The development of nutritional strategies to improve microbial homeostasis and gut health of piglets post-weaning is required to mitigate the high prevalence of post-weaning diarrhea and subsequent growth checks typically observed during the weaning transition. Therefore the objective of this study was to determine the effect of supplementing piglet creep and nursery feed with a yeast-derived mannan-rich fraction (MRF) on piglet growth performance, cecal microbial profiles, and jejunal morphology and gene expression. Ten litters of piglets (n=106) were selected on postnatal day (PND) 7 and assigned to diets with or without MRF (800 mg/kg) until weaning (n=5 litters/treatment; initial weight 3.0±0.1 kg). On PND 21, 4 piglets per litter (n=40) were selected and weaned into the nursery where they remained on their respective diets until PND 42. A two-phase feeding program was used to meet nutrient requirements, and pigs were switched from phase 1 to phase 2 on PND 28. Feed intake and piglet weights were recorded on PND 7, 14, 21, 28, 35 and 42. On PND 28 and 42, ten piglets per treatment were euthanized to collect intestinal tissue and digesta. Piglets supplemented with MRF had 21.5% greater (P<0.05) average daily feed intake between PND 14-21. However, MRF supplementation did not affect piglet growth performance compared to control. On PND 28, jejunal villus height was 16.8% greater (P<0.05) in piglets consuming MRF supplemented diets. Overall microbial community structure in cecal digesta on PND 28 tended to differ in pigs supplemented with MRF (P=0.076; analysis of similarities (ANOSIM)) with increased (P<0.05) relative abundance of Paraprevotellaceae genera YRC22 and CF231, and reduced (P<0.05) relative abundance of Sutterella and Prevotella. Campylobacter also tended to reduce (P<0.10) in MRF supplemented piglets. On PND 28 differential gene expression in jejunal tissue signified an overall effect of supplementing MRF to piglets. Downstream analysis of gene expression data revealed piglets supplemented with MRF had enriched biological pathways involved in intestinal development, function and immunity, supporting the observed improvement in jejunal villus architecture on PND 28. On PND 42 there was no effect of MRF supplementation on jejunal morphology or overall cecal microbial community structure. In conclusion, supplementing Actigen™, a MRF, to piglets altered cecal microbial community structure and improved jejunal morphology early post-weaning on PND 28, which is supported by enrichment of intestinal development pathways.
We have found that 4 new, bright IRAS quasars, out of 7 observed, have strong, non-variable, wavelength-dependent polarization. Three show degrees of polarization, pλ, increasing from infrared to UV wavelengths (Fig. 1), which implies a combination of a polarized, scattered spectrum and a much redder, unpolarized spectrum. Detailed IR and optical polarimetry and spectrophotometry of one, IRAS 13349+2438 (Wills et al.), shows a polarized flux spectrum, pλxFλ, (continuum and Pa α, Hα, and Hβ broad hydrogen lines) typical of unreddened, luminous quasars. This suggests that the path of scattered light from a central, luminous quasar is low in dust and that the polarization of the scattered spectrum is wavelength independent. The latter is most easily explained by electron scattering although the data do not exclude dust scattering. When this polarized flux spectrum is subtracted from the total spectrum, we are left with a very reddened line and continuum spectrum, E(B-V) = 0.3 to 0.7, which we attribute to the same luminous quasar seen through a thick dusty torus. The angle of polarization is parallel to the major axis of the r-band image, presumed to be that of the host galaxy. If the torus is in the plane of the galaxy, the axial ratio suggests a viewing angle of 40° to the plane of the torus. Fig. 2 illustrates the geometry. The appearance of the quasar at optical and UV wavelengths will depend strongly on viewing angle, suggesting that present samples of quasars selected by colours, optical flux density, or quasi-stellar appearance, may be seriously biased, with important consequences for studies of the space density and evolution of AGN.
We have made a polarimetric survey of 84 quasi-stellar objects, to supplement published polarization measurements for two samples of quasars identified with flat-spectrum (core-dominant) radio sources in 5 GHz surveys made at Bonn (Kühr 1980) and at the VLA (Perley 1982). The observations were made using the McDonald 2.1m Struve reflector and the polarimeter described by Breger (1979); the typical accuracy is 0.5% for an 18 mag object after half an hour. Earlier surveys, such as those by Stockman, Moore and Angel (1984), included objects of various radio spectral types, and only a small fraction of the objects showed high polarization (> 3%), but our sample of flat-spectrum quasars reveals many more (about half) of the objects to be highly polarized. Some of them are, expectedly, of the BL Lac class, but many of them have strong broad emission lines. There are two striking correlations among the results:
(1)The degree of polarization is strongly correlated with the dominance of the radio core - specifically, with the ratio, R, of core to lobe luminosity (Fig. 1). For example, about 75% of the objects with log R > 1.25 and redshift z < 1 have p > 3%. This relation implies that if the radio core radiation is beamed, as seems likely, then so is the optical synchrotron component.
(2)The fraction of objects with p > 3% is inversely correlated with redshift (e.g. Fig. 2). The most likely interpretation of this result is that quasars' degree of polarization decreases with decreasing rest wavelength, and the shorter wavelengths are shifted into our wide observational passband at higher redshifts.
Hantaviruses are globally distributed and cause severe human disease. Puumala hantavirus (PUUV) is the most common species in Northern Europe, and the only hantavirus confirmed to circulate in Sweden, restricted to the northern regions of the country. In this study, we aimed to further add to the natural ecology of PUUV in Sweden by investigating prevalence, and spatial and host species infection patterns. Specifically, we wanted to ascertain whether PUUV was present in the natural reservoir, the bank vole (Myodes glareolus) further south than Dalälven river, in south-central Sweden, and whether PUUV can be detected in other rodent species in addition to the natural reservoir. In total, 559 animals were collected at Grimsö (59°43′N; 15°28′E), Sala (59°55′N; 16°36′E) and Bogesund (59°24′N; 18°14′E) in south-central Sweden between May 2013 and November 2014. PUUV ELISA-reactive antibodies were found both in 2013 (22/295) and in 2014 (18/264), and nine samples were confirmed as PUUV-specific by focus reduction neutralization test. Most of the PUUV-specific samples were from the natural host, the bank vole, but also from other rodent hosts, indicating viral spill-over. Finally, we showed that PUUV is present in more highly populated central Sweden.
To investigate socio-economic differences in children’s diet, activity and inactivity and changes in these differences over 4 years during which new policies on food in schools were introduced.
Two cross-sectional surveys in which diet was assessed by FFQ and physical activity and inactivity were assessed by interviewer-administered questionnaire. Socio-economic status was assessed by the area-based Scottish Index of Multiple Deprivation.
Scotland, 2006 and 2010.
Children aged 3–17 years (n 1700 in 2006, n 1906 in 2010).
In both surveys there were significant linear associations between socio-economic deprivation and intakes of energy, non-milk extrinsic sugars (NMES) as a percentage of food energy, sugar-sweetened beverages, confectionery, crisps and savoury snacks and leisure-time screen use (all higher among children in more deprived areas), while intakes of fruit, fruit juice and vegetables showed the opposite trend. In 2010 children in more deprived areas engaged in more physical activity out of school than those in more affluent areas, but between 2006 and 2010 there was an overall reduction in physical activity out of school. There were also small but statistically significant overall reductions in intakes of confectionery, crisps and savoury snacks, energy and NMES and saturated fat as a percentage of food energy, but no statistically significant change in socio-economic gradients in diet or activity between the two surveys.
Interventions to improve diet and physical activity in children in Scotland need to be designed so as to be effective in all socio-economic groups.
The displacement of the surface of an ice sheet and of markers set in its top layers can be measured geodetically, and also, it is expected, by radio-echo methods. The paper discusses how such measurements could be interpreted as showing long-term changes in the thickness of the ice sheet; in particular it discusses how one might design an experiment so as to avoid unwanted effects due to short-term changes in rate of accumulation. The analysis is similar to that of Federer and others (1970), but it corrects an error, so that when applied to their results for central Greenland it gives a different result for the lowering of the surface. Federer and others have already concluded that the average accumulation rates during the past 100 years have been below those needed to keep in balance with the velocity of the ice sheet as a whole. Using a particular model, it is found that this has resulted in the surface lowering at a mean rate of 0.050 m a−1 between 1871 and 1968, and a mean rate of 0.140 m a−1 between 1959 and 1968.
The IR-optical-UV continua of quasars are often represented by two components: (i) a flat spectrum component dominating in the optical-UV (the “Big Bump”) and sometimes attributed to thermal radiation from an accretion disk with temperatures of about 20000 to 40000 K - we will call it the “disk” component - and (ii) a near IR component characterized by a steep rise, α ∼ 1 for λ > 1 μm, often thought to be a synchrotron spectrum - an extrapolation of the cm or mm wavelength radio spectrum - although some have preferred an explanation in terms of thermal re-radiation of the ionizing continuum by hot dust (e.g., Hyland and Allen 1982, Neugebauer et al. 1979).
Some years ago, Bolton, Peterson, Wills and Wills (1976, BPWW) reported a statistically-significant excess of QSOs within 2' arc of flat spectrum radio-selected QSOs (specifically, they found 5 such objects while only 1 was expected by chance). None of the QSO pairs had the same redshifts so the result could be regarded as evidence for non-cosmological redshifts, non-uniform QSO distributions, or a statistical fluctuation. Because of the potential importance of BPWW's result, we later used the same technique to examine an independent sample of about 150 QSOs with flat radio spectra and found results that are consistent with the known surface density of QSOs. If we assume a surface density of 3.3 QSOs per square degree brighter than B = 19 (e.g. Marshall et al. 1983), the 150 fields each of 2' arc radius should contain 1.7 random QSOs above this limit and we found 2 (e.g. Wills 1978). A third object is very close to B = 19, and another field contains an object that is extremely blue, with B < 19, on the Palomar Sky Survey, but below our plate limit (i.e. B > 21); we have so far been unable to obtain a spectrum for it. One of the 3 confirmed QSOs is 119″ arc from the radio-emitting one, so rather small changes in the magnitude limit, search radius and choice of epoch at which the magnitudes are measured can result in there being anywhere between 1 and 4 secondary QSOs (or 1–3 if the variable object is not a QSO), compared with 2 expected by chance, and perhaps 10 that would be predicted by BPWW's results.
“Standard” photoionization models of the broad line region (BLR) consist of numerous small optically thick clouds of identical ionization, density, temperature and optical depth, moving under the influence of the gravity and radiation field of a 107–8 M⊙ black hole and confined by a high temperature gas. Such models have provided a good description of observed line strengths and widths with only very minor modification. Although photoionization remains the most important heating mechanism in the BLR, new observations point to a wider range of physical conditions and to clues about the geometric and dynamic arrangement of the emitting gas. I want to highlight the observations that have led us to this view.
We report briefly on our optical spectroscopy of QSOs from the radio survey in progress at the University of Texas Radio Astronomy Observatory (UTRAO). The radio survey, under the direction of Dr J. N. Douglas, covers declinations north of −36 degrees, in strips that are 9 degrees wide in declination. Preliminary results for the strip centered at +18 degrees have been published (Douglas et al. 1980) and other strips are currently being prepared for publication. The complete catalogue will list 1 arcsec positions and some structure information for about 75,000 sources stronger than about 250 mJy at 365 MHz. Optical identifications are made from the Palomar Observatory Sky Survey plates using an interactive laser measuring machine (Ghigo 1977), and the accuracy of the radio source positions allows the identifications to be made regardless of the colours of the objects. Optical spectroscopy of a sample of about 300 QSO candidates brighter than 19 mag, drawn from the +36, +18 and −12 degree strips, is being carried out at McDonald Observatory using an Intensified Dissector Scanner at the cassegrain focus of the 2.7m reflector. Two image-tube and dissector chains are available, together covering the range 3200–8500 A; a typical spectrum takes 1 hour to obtain, with wavelength resolution of 10 A over a total range of 3000 A.
For very small samples, it is difficult to prepare graphitic targets that will yield a useful and steady sputtered ion beam. Working with materials separated by preparative capillary gas chromatography, we have succeeded with amounts as small as 20 μg C. This seems to be a practical limit, as it involves 1) multiple chromatographic runs with trapping of effluent fractions, 2) recovery and combustion of the fractions, 3) graphitization and 4) compression of the resultant graphite/cobalt matrix into a good sputter target. Through such slow and intricate work, radiocarbon ages of lignin derivatives and hydrocarbons from coastal sediments have been determined. If this could be accomplished as an “online” measurement by flowing the analytes directly into a microwave gas ion source, with a carrier gas, then the number of processing steps could be minimized. Such a system would be useful not just for chromatographic effluents, but for any gaseous material, such as CO2 produced from carbonates. We describe tests using such an ion source.
Recent archaeological investigations at Pueblo Bonito in Chaco Canyon reveal that residents constructed a large diversion channel during the eleventh century A.D. as dramatic growth resulted in the expansion of the building onto the main valley floor. Sediments in the diversion channel reflect repeated episodes of flooding, rather than slow moving water typically found in irrigation canals, and archaeobotanical data indicate deposition during late summer or early fall. Although an agricultural function is possible, the channel may have been built primarily to divert floodwaters away from Pueblo Bonito while providing a nearby water source for construction and domestic use. The diversion channel was destroyed by the entrenchment of the “Bonito paleo-channel” in the late A.D. 1000s, and then buried by a combination of cultural debris and valley flooding. Although the canyon stream system changed throughout the occupation of Pueblo Bonito, there is no evidence that the formation of a deep natural channel in the floodplain had any negative effect on the growth of the great house
The coalescence of two Langmuir waves, L and L′, produces emission at twice the plasma frequency in type II and type III solar radio bursts. The analysis of the coalescence process is usually simplified by assuming the head-on approximation, where the wavevectors of the coalescing waves satisfy kL′ ≈ −kL, corresponding to the two Langmuir waves meeting head on. However, this is not always a valid approximation, particularly when the peak of the Langmuir spectrum lies at small wavenumbers, for narrow band spectra, and for spectra with broad angular ranges. Realistic Langmuir wave spectra are used to investigate the effects of relaxing the head-on approximation.
We are analyzing the emission lines and continuum spectra of a sample of ~61 radio-loud quasars to investigate dependences amongst various spectral, radio, and X-ray parameters, in particular to look for dependences of spectral properties on inclination of the the radio-jet axis (Wills et al. 1997).
We have carried out conventional correlation analyses, as well as spectral principal-component analyses (SPCA) as described in the previous paper (Wills et al. 1997). We found that the single largest contribution to the spectrum-tospectrum variations was from a component — the ‘first principal component’ (PC1) — that has a more UV (or less red) continuum than the mean spectrum, and a weaker narrow-line (NLR) spectrum. The ‘second principal component’ (PC2) accounts for only 8–12% of the spectrum-to-spectrum variation, contributing a weaker UV, and stronger red continuum, and showing stronger narrow emission lines. There is also a tendency for the broad (BLR) lines in the second principal component spectrum to be narrower (note the sharper He II λ1640 and [O III] λ1663 features redward of the stronger C IV λ1549 emission line, and perhaps a narrow component of the N V λ1240 line redward of Lyα).
We have obtained HST and ground-based spectrophotometry of a sample of ~61 radio-loud quasars from shortward of Lyα to longward of Hβ. The aim was to investigate the dependence of quasar properties on orientation of the central engine axis to the observer’s line of sight. As an approximate measure of inclination we use the radio core-dominance, i.e., the ratio of beamed radiocore emission to the emission in the extended lobes at 5 GHz rest frequency. About half the radio sources have core-dominance greater than unity (jet or axis pointed close to our line of sight). Quasar pairs were matched in radio lobe luminosity and redshift to reduce bias caused by strong dependences on intrinsic luminosity.
Observation and reduction techniques were standard, and the spectral resolution is equivalent to 230–400 km s−1 (Wills et al. 1993). We have performed correlation analyses among emission-line and continuum parameters, as well as spectral principal-component analyses (SPCA, Francis et al. 1992).
The role of wild meat for subsistence or as a luxury good is debated. We investigated the role of wild meat in food security in Madagascar, where consumption is poorly understood in urban areas and at regional scales. Using semi-structured interviews (n = 1339 heads-of-households, 21 towns), we aimed to: (1) quantify the amount and purpose of, (2) understand the drivers of, and (3) examine changes in wild meat consumption. Few respondents preferred wild meat (8 ± 3%) but most had eaten it at least once in their lifetime (78 ± 7%). Consumption occurred across ethnic groups, in urban and rural settings. More food insecure areas reported higher rates of wild meat consumption in the 6–8 months prior to interviews. Consumption was best explained by individual preferences and taboos. Less than 1% of respondents had increased consumption during their lifetimes. Wild meat prices showed no change from 2005–2013. Most consumption involved wild pigs and smaller-sized animals, though they were consumed less in the years following the 2009 coup. These data illustrate the differences between urban and rural communities, the occasions in which wild meat is used a source of food security, and provide evidence that some taxa are not hunted sustainably in Madagascar.
Relations between observed optical and radio properties can, in principle, constrain the geometry and physical conditions of the broad-line regions in quasars and active nuclei. Osterbrock and colleagues (see this symposium) and J.E. Steiner (preprint) have noted differences between Hα/Hβ, [0III]/Hβ and optical Fe II emission for Seyfert 1 galaxies, broad-line radio galaxies (BLRG's) and quasars. Stockman et al. (1979) discovered a tendency for optical continuum polarization angles for quasars to be aligned with the direction of the outer radio lobes. Setti and Woltjer (1977) and Miley and Miller (1979) noted that the quasars with strongest Fe II are among the most compact radio sources (e.g. 3C 48, 0736+01, 1510–08), and Miley and Miller also note that the distribution of line widths is narrower for the more compact than for extended radio sources.
A γ-Ray telescope incorporating an acoustic spark chamber is included in the payload of the OGO-5 spacecraft. The performance of the instrument, which is sensitive to photons of energy 25 to 100 MeV, is discussed.
Observations are limited to a portion of the sky near Cygnus, but the first month's data indicate a variation of intensity showing a maximum in the direction of the galactic plane. If this plane contains a line source of radiation, its intensity is found to be (9 ± 5) × 10−4 photons cm−2 sec−1 rad−1 above an energy of 40 MeV.
The ESRO satellite COS-B carries one single experiment aiming at the measurement of arrival direction and energy of celestial gamma rays with energies between 25 MeV and 10 GeV. The experiment is conventional in design and consists of a veto counter, a wire spark chamber, a telescope and an energy calorimeter.
The energy measurement is obtained by a CsI scintillation crystal of 4.7 radiation length thickness. The expected energy resolution at 100 MeV is 50% FWHM. The other detector elements are designed as to cause the least possible degradation of the energy measurement.
The possibilities for the detection of a small contribution of π -origin gamma rays in the presence of a power-law type background spectrum will be discussed.