Impacts of in Utero Heat Stress on Carcass and Meat Quality Traits of Market Weight Gilts

This study evaluated the impacts of in utero heat stress (IUHS) on the carcass and meat quality traits of offspring when market weight was reached. Twenty-four F1 Landrace × Large White gilts were blocked by body weight and allocated among thermoneutral (IUTN) or IUHS treatments from d 6 to d 59 of gestation. The offspring were raised under identical thermoneutral conditions, and gilts (n = 10/treatment) at market weight (117.3 ± 1.7 kg) were harvested. At 24 h postmortem, the loins (M. longissimus lumborum) were obtained, and sections were allocated among 1 d and 7 d aging treatments at 2 °C. Carcasses from IUHS pigs had lower head and heart weights (p p p p > 0.05), and Western blots suggested increased toughness of IUHS loins would not be attributed to proteolysis. These results suggest minimizing IUHS during the first half of gestation may be beneficial in improving pork yield and quality, though in general the effects of IUHS would be minimal

Impacts of in Utero Heat Stress on Carcass and Meat Quality Traits of Market Weight Gilts

This study evaluated the impacts of in utero heat stress (IUHS) on the carcass and meat quality traits of offspring when market weight was reached. Twenty-four F1 Landrace × Large White gilts were blocked by body weight and allocated among thermoneutral (IUTN) or IUHS treatments from d 6 to d 59 of gestation. The offspring were raised under identical thermoneutral conditions, and gilts (n = 10/treatment) at market weight (117.3 ± 1.7 kg) were harvested. At 24 h postmortem, the loins (M. longissimus lumborum) were obtained, and sections were allocated among 1 d and 7 d aging treatments at 2 °C. Carcasses from IUHS pigs had lower head and heart weights (p < 0.05), as well as decreased loin muscle area (p < 0.05) compared to IUTN pigs. Loins from the IUHS group had a higher shear force value than the IUTN group (p < 0.05). Treatments had no other impacts on carcass and meat quality traits (p > 0.05), and Western blots suggested increased toughness of IUHS loins would not be attributed to proteolysis. These results suggest minimizing IUHS during the first half of gestation may be beneficial in improving pork yield and quality, though in general the effects of IUHS would be minimal

Organic farming positively affects honeybee colonies in a flower‐poor period in agricultural landscapes

1. Conventional farming has been implicated in global biodiversity and pollinatordeclines and organic farming is often regarded as a more ecological alternative.However, the effects of organic farming on honeybees remain elusive, despitehoneybees’ importance as pollinators of crops and wild plants.2. Using 6 years of data from a large‐scale study with fortnightly measurements ofhoneybee colony performance traits (10 apiaries per year distributed across a435 km2‐large research site in France), we related worker brood area, number ofadult bees and honey reserves to the proportions of organic farmland in the surroundingsof the hives at two spatial scales (300 m and 1,500 m).3. We found evidence that, at the local scale, organic farming increased both workerbrood production and number of adult bees in the period of flower scarcity betweenthe blooms of oilseed rape and sunflower (hereafter ‘dearth period’). Atthe landscape scale, organic farming increased honey reserves during the dearthperiod and at the beginning of the sunflower bloom.4. The results suggest that worker brood development benefitted from organic farmingmostly through a more diverse diet due to an increase in the availability of diversepollen sources in close proximity of their hives. Reduced pesticide drift mayhave additionally improved bee survival. Honey reserves were possibly mostlyaffected by increased availability of melliferous flowers in foraging distance.5. Synthesis and applications. Organic farming increases honeybee colony performancein a period of resource scarcity, likely through a continuous supply of floral resourcesincluding weeds, cover crops and semi‐natural elements. We demonstratehow worker brood area increases in the critical dearth period (between the bloomsof oilseed rape and sunflower). This has previously been linked to winter colonysurvival, suggesting that organic farmland may mitigate repercussions of intensivefarming on colony vitality. We conclude that organic farming benefits a crucial croppollinator with potential positive implications for agriculture in the wider landscap

Status of mirror segment production for the Giant Magellan Telescope

The Richard F. Caris Mirror Lab at the University of Arizona is responsible for production of the eight 8.4 m segments for the primary mirror of the Giant Magellan Telescope, including one spare off-axis segment. We report on the successful casting of Segment 4, the center segment. Prior to generating the optical surface of Segment 2, we carried out a major upgrade of our 8.4 m Large Optical Generator. The upgrade includes new hardware and software to improve accuracy, safety, reliability and ease of use. We are currently carrying out an upgrade of our 8.4 m polishing machine that includes improved orbital polishing capabilities. We added and modified several components of the optical tests during the manufacture of Segment 1, and we have continued to improve the systems in preparation for Segments 2-8. We completed two projects that were prior commitments before GMT Segment 2: casting and polishing the combined primary and tertiary mirrors for the LSST, and casting and generating a 6.5 m mirror for the Tokyo Atacama Observatory.SPIE grants to authors of papers published in an SPIE Journal or Proceedings the right to post an author-prepared version or an official version (preferred version) of the published paper on an internal or external server controlled exclusively by the author/employer, provided that (a) such posting is noncommercial in nature and the paper is made available to users without charge; (b) an appropriate copyright notice and full citation appear with the paper, and (c) a link to SPIE's official online version of the abstract is provided using the DOI (Document Object Identifier) link.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

The New LOTIS Test Facility

The Large Optical Test and Integration Site (LOTIS) at the Lockheed Martin Space Systems Company in Sunnyvale, CA is designed for the verification and testing of optical systems. The facility consists of an 88 foot temperature stabilized vacuum chamber that also functions as a class 10k vertical flow cleanroom. Many problems were encountered in the design and construction phases. The industry capability to build large chambers is very weak. Through many delays and extra engineering efforts, the final product is very good. With 11 Thermal Conditioning Units and precision RTD s, temperature is uniform and stable within 1oF, providing an ideal environment for precision optical testing. Within this chamber and atop an advanced micro-g vibration-isolation bench is the 6.5 meter diameter LOTIS Collimator and Scene Generator, LOTIS alignment and support equipment. The optical payloads are also placed on the vibration bench in the chamber for testing. This optical system is designed to operate in both air and vacuum, providing test imagery in an adaptable suite of visible/near infrared (VNIR) and midwave infrared (MWIR) point sources, and combined bandwidth visible-through-MWIR point sources, for testing of large aperture optical payloads. The heart of the system is the LOTIS Collimator, a 6.5m f/15 telescope, which projects scenes with wavefront errors <85 nm rms out to a 0.75 mrad field of view (FOV). Using field lenses, performance can be extended to a maximum field of view of 3.2 mrad. The LOTIS Collimator incorporates an extensive integrated wavefront sensing and control system to verify the performance of the system

Production of primary mirror segments for the Giant Magellan Telescope

ABSTRACT Segment production for the Giant Magellan Telescope is well underway, with the off-axis Segment 1 completed, off-axis Segments 2 and 3 already cast, and mold construction in progress for the casting of Segment 4, the center segment. All equipment and techniques required for segment fabrication and testing have been demonstrated in the manufacture of Segment 1. The equipment includes a 28 m test tower that incorporates four independent measurements of the segment&apos;s figure and geometry. The interferometric test uses a large asymmetric null corrector with three elements including a 3.75 m spherical mirror and a computer-generated hologram. For independent verification of the large-scale segment shape, we use a scanning pentaprism test that exploits the natural geometry of the telescope to focus collimated light to a point. The Software Configurable Optical Test System, loosely based on the Hartmann test, measures slope errors to submicroradian accuracy at high resolution over the full aperture. An enhanced laser tracker system guides the figuring through grinding and initial polishing. All measurements agree within the expected uncertainties, including three independent measurements of radius of curvature that agree within 0.3 mm. Segment 1 was polished using a 1.2 m stressed lap for smoothing and large-scale figuring, and a set of smaller passive rigid-conformal laps on an orbital polisher for deterministic small-scale figuring. For the remaining segments, the Mirror Lab is building a smaller, orbital stressed lap to combine the smoothing capability with deterministic figuring

Manufacture and final tests of the LSST monolithic primary/tertiary mirror

The LSST M1/M3 combines an 8.4 m primary mirror and a 5.1 m tertiary mirror on one glass substrate. The combined mirror was completed at the Richard F. Caris Mirror Lab at the University of Arizona in October 2014. Interferometric measurements show that both mirrors have surface accuracy better than 20 nm rms over their clear apertures, in near-simultaneous tests, and that both mirrors meet their stringent structure function specifications. Acceptance tests showed that the radii of curvature, conic constants, and alignment of the 2 optical axes are within the specified tolerances. The mirror figures are obtained by combining the lab measurements with a model of the telescope's active optics system that uses the 156 support actuators to bend the glass substrate. This correction affects both mirror surfaces simultaneously. We showed that both mirrors have excellent figures and meet their specifications with a single bending of the substrate and correction forces that are well within the allowed magnitude. The interferometers do not resolve some small surface features with high slope errors. We used a new instrument based on deflectometry to measure many of these features with sub-millimeter spatial resolution, and nanometer accuracy for small features, over 12.5 cm apertures. Mirror Lab and LSST staff created synthetic models of both mirrors by combining the interferometric maps and the small high-resolution maps, and used these to show the impact of the small features on images is acceptably small.SPIE grants to authors of papers published in an SPIE Journal or Proceedings the right to post an author-prepared version or an official version (preferred version) of the published paper on an internal or external server controlled exclusively by the author/employer, provided that (a) such posting is noncommercial in nature and the paper is made available to users without charge; (b) an appropriate copyright notice and full citation appear with the paper, and (c) a link to SPIE's official online version of the abstract is provided using the DOI (Document Object Identifier) link.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]