Increase sustainability of organic pig production with more vital piglets

About every third piglet dies before weaning within the Danish organic pig production, making the organic piglet mortality higher, than what is seen in the conventional indoor production. The high piglet mortality is in conflict with both the idea of increased animal welfare and the organic principles. As most of the piglets die within the first days after farrowing, improving the thermal conditions around the time of farrowing is important, since the thermal environment in many cases may be a significant contributor to piglet death also for piglets that are categorized as crushed or starved to death. This paper describes a subproject under the larger Danish VIPiglets project with the overall aim to reduce piglet mortality in Danish organic pig production. The subproject described in this paper has three overall aims concerning 1) ways to improve the thermal environment around the time of farrowing 2) how the temperature and humidity inside the farrowing hut relate to piglet mortality 3) how temperature affects farrowing duration and inter birth interval. Studies concerning aim two and three are still ongoing and so no results are presented. In the study concerning aim one the average total litter size was 17 piglets and total piglet mortality was 31%. The study showed that providing sows with access to poplar trees (a shaded area) significantly affected paddock use compared to sows without a shaded area (control sows), by increasing the use of the paddock before farrowing and day zero and one post partum (pp) (F4,218=2.91, p<0.05) and the paddock use particularly increased at hot temperatures. Furthermore the sows with access to poplar were lying more when outside compared to controls (29 % vs 18 % respectively; F1,70=15.13, p<0.0005). In general the sows were seen lying more in the paddock at high temperature compared to low temperature particularly before farrowing, on day 0 and 1 pp and again after day 11 pp

Identification of sow level risk factors on early piglet mortality in Danish organic sow herds during different seasons

The objective of this study was to identify season, litter size, sow parity and sow health as risk factors for still birth and early piglet mortality in Danish organic pig herds

Some Aspects of Rotational and Magnetic Energies for a Hierarchy of Celestial Objects

Celestial objects, from earth like planets to clusters of galaxies, possess angular momentum and magnetic fields. Here we compare the rotational and magnetic energies of a whole range of these celestial objects together with their gravitational self energies and find a number of interesting relationships. The celestial objects, due to their magnetic fields, also posses magnetic moments. The ratio of magnetic moments of these objects with the nuclear magnetic moments also exhibits interesting trends. We also compare their gyromagnetic ratio which appears to fall in a very narrow range for the entire hierarchy of objects. Here we try to understand the physical aspects implied by these observations and the origin of these properties in such a wide range of celestial objects, spanning some twenty orders in mass, magnetic field and other parameters.Comment: 12 pages, 37 equation

Behaviour of organic lactating sows given access to poplar trees

The aim of the current study was to investigate how access to poplar trees (an alternative shaded area) affects signs of heat stress and paddock use in lactating sows

Some general properties of the renormalized stress-energy tensor for static quantum states on (n+1)-dimensional spherically symmetric black holes

We study the renormalized stress-energy tensor (RSET) for static quantum states on (n+1)-dimensional, static, spherically symmetric black holes. By solving the conservation equations, we are able to write the stress-energy tensor in terms of a single unknown function of the radial co-ordinate, plus two arbitrary constants. Conditions for the stress-energy tensor to be regular at event horizons (including the extremal and ``ultra-extremal'' cases) are then derived using generalized Kruskal-like co-ordinates. These results should be useful for future calculations of the RSET for static quantum states on spherically symmetric black hole geometries in any number of space-time dimensions.Comment: 9 pages, no figures, RevTeX4, references added, accepted for publication in General Relativity and Gravitatio

Comparison of large-scale flows on the Sun measured by time-distance helioseismology and local correlation tracking technique

We present a direct comparison between two different techniques time-distance helioseismology and a local correlation tracking method for measuring mass flows in the solar photosphere and in a near-surface layer: We applied both methods to the same dataset (MDI high-cadence Dopplergrams covering almost the entire Carrington rotation 1974) and compared the results. We found that after necessary corrections, the vector flow fields obtained by these techniques are very similar. The median difference between directions of corresponding vectors is 24 degrees, and the correlation coefficients of the results for mean zonal and meridional flows are 0.98 and 0.88 respectively. The largest discrepancies are found in areas of small velocities where the inaccuracies of the computed vectors play a significant role. The good agreement of these two methods increases confidence in the reliability of large-scale synoptic maps obtained by them.Comment: 14 pages, 6 figures, just before acceptance in Solar Physic

Transiting Exoplanets with JWST

The era of exoplanet characterization is upon us. For a subset of exoplanets -- the transiting planets -- physical properties can be measured, including mass, radius, and atmosphere characteristics. Indeed, measuring the atmospheres of a further subset of transiting planets, the hot Jupiters, is now routine with the Spitzer Space Telescope. The James Webb Space Telescope (JWST) will continue Spitzer's legacy with its large mirror size and precise thermal stability. JWST is poised for the significant achievement of identifying habitable planets around bright M through G stars--rocky planets lacking extensive gas envelopes, with water vapor and signs of chemical disequilibrium in their atmospheres. Favorable transiting planet systems, are, however, anticipated to be rare and their atmosphere observations will require tens to hundreds of hours of JWST time per planet. We review what is known about the physical characteristics of transiting planets, summarize lessons learned from Spitzer high-contrast exoplanet measurements, and give several examples of potential JWST observations.Comment: 22 pages, 11 figures. In press in "Astrophysics in the Next Decade: JWST and Concurrent Facilities, Astrophysics & Space Science Library, Thronson, H. A., Tielens, A., Stiavelli, M., eds., Springer: Dordrecht (2008)." The original publication will be available at http://www.springerlink.co

Rev1 deficiency induces a metabolic shift in MEFs that can be manipulated by the NAD plus precursor nicotinamide riboside

Replication stress, caused by Rev1 deficiency, is associated with mitochondrial dysfunction, and metabolic stress. However, the overall metabolic alterations and possible interventions to rescue the deficits due to Rev1 loss remain unclear. Here, we report that loss of Rev1 leads to intense changes in metabolites and that this can be manipulated by NAD + supplementation. Autophagy decreases in Rev1-/- mouse embryonic fibroblasts (MEFs) and can be restored by supplementing the NAD+ precursor nicotinamide riboside (NR). The abnormal mitochondrial morphology in Rev1-/-MEFs can be partially reversed by NR supplementation, which also protects the mito-chondrial cristae from rotenone-induced degeneration. In nematodes rev-1 deficiency causes sensitivity to oxidative stress but this cannot be rescued by NR supplementation. In conclusion, Rev1 deficiency leads to metabolic dysregulation of especially lipid and nucleotide metabolism, impaired autophagy, and mitochondrial anomalies, and all of these phenotypes can be improved by NR replenishment in MEFs.Genome Instability and Cance

Neutrino masses: From fantasy to facts

Theory suggests the existence of neutrino masses, but little more. Facts are coming close to reveal our fantasy: solar and atmospheric neutrino data strongly indicate the need for neutrino conversions, while LSND provides an intriguing hint. The simplest ways to reconcile these data in terms of neutrino oscillations invoke a light sterile neutrino in addition to the three active ones. Out of the four neutrinos, two are maximally-mixed and lie at the LSND scale, while the others are at the solar mass scale. These schemes can be distinguished at neutral-current-sensitive solar & atmospheric neutrino experiments. I discuss the simplest theoretical scenarios, where the lightness of the sterile neutrino, the nearly maximal atmospheric neutrino mixing, and the generation of $\Delta {m^2}_\odot$ & $\Delta {m^2}_{atm}$ all follow naturally from the assumed lepton-number symmetry and its breaking. Although the most likely interpretation of the present data is in terms of neutrino-mass-induced oscillations, one still has room for alternative explanations, such as flavour changing neutrino interactions, with no need for neutrino mass or mixing. Such flavour violating transitions arise in theories with strictly massless neutrinos, and may lead to other sizeable flavour non-conservation effects, such as $\mu \to e + \gamma$, $\mu-e$ conversion in nuclei, unaccompanied by neutrino-less double beta decay.Comment: 33 pages, latex, 16 figures. Invited Talk at Ioannina Conference, Symmetries in Intermediate High Energy Physics and its Applications, Oct. 1998, to be published by Springer Tracts in Modern Physics. Festschrift in Honour of John Vergados' 60th Birthda

Dust Devil Tracks

Dust devils that leave dark- or light-toned tracks are common on Mars and they can also be found on the Earth’s surface. Dust devil tracks (hereinafter DDTs) are ephemeral surface features with mostly sub-annual lifetimes. Regarding their size, DDT widths can range between ∼1 m and ∼1 km, depending on the diameter of dust devil that created the track, and DDT lengths range from a few tens of meters to several kilometers, limited by the duration and horizontal ground speed of dust devils. DDTs can be classified into three main types based on their morphology and albedo in contrast to their surroundings; all are found on both planets: (a) dark continuous DDTs, (b) dark cycloidal DDTs, and (c) bright DDTs. Dark continuous DDTs are the most common type on Mars. They are characterized by their relatively homogenous and continuous low albedo surface tracks. Based on terrestrial and martian in situ studies, these DDTs most likely form when surficial dust layers are removed to expose larger-grained substrate material (coarse sands of ≥500 μm in diameter). The exposure of larger-grained materials changes the photometric properties of the surface; hence leading to lower albedo tracks because grain size is photometrically inversely proportional to the surface reflectance. However, although not observed so far, compositional differences (i.e., color differences) might also lead to albedo contrasts when dust is removed to expose substrate materials with mineralogical differences. For dark continuous DDTs, albedo drop measurements are around 2.5 % in the wavelength range of 550–850 nm on Mars and around 0.5 % in the wavelength range from 300–1100 nm on Earth. The removal of an equivalent layer thickness around 1 μm is sufficient for the formation of visible dark continuous DDTs on Mars and Earth. The next type of DDTs, dark cycloidal DDTs, are characterized by their low albedo pattern of overlapping scallops. Terrestrial in situ studies imply that they are formed when sand-sized material that is eroded from the outer vortex area of a dust devil is redeposited in annular patterns in the central vortex region. This type of DDT can also be found in on Mars in orbital image data, and although in situ studies are lacking, terrestrial analog studies, laboratory work, and numerical modeling suggest they have the same formation mechanism as those on Earth. Finally, bright DDTs are characterized by their continuous track pattern and high albedo compared to their undisturbed surroundings. They are found on both planets, but to date they have only been analyzed in situ on Earth. Here, the destruction of aggregates of dust, silt and sand by dust devils leads to smooth surfaces in contrast to the undisturbed rough surfaces surrounding the track. The resulting change in photometric properties occurs because the smoother surfaces have a higher reflectance compared to the surrounding rough surface, leading to bright DDTs. On Mars, the destruction of surficial dust-aggregates may also lead to bright DDTs. However, higher reflective surfaces may be produced by other formation mechanisms, such as dust compaction by passing dust devils, as this may also cause changes in photometric properties. On Mars, DDTs in general are found at all elevations and on a global scale, except on the permanent polar caps. DDT maximum areal densities occur during spring and summer in both hemispheres produced by an increase in dust devil activity caused by maximum insolation. Regionally, dust devil densities vary spatially likely controlled by changes in dust cover thicknesses and substrate materials. This variability makes it difficult to infer dust devil activity from DDT frequencies. Furthermore, only a fraction of dust devils leave tracks. However, DDTs can be used as proxies for dust devil lifetimes and wind directions and speeds, and they can also be used to predict lander or rover solar panel clearing events. Overall, the high DDT frequency in many areas on Mars leads to drastic albedo changes that affect large-scale weather patterns