469 research outputs found
Sow and Litter Performance for Individual Crate and Group Hoop Barn Gestation Housing Systems: A Progress Report II
The effects of swine gestation housing on sow and litter performance were evaluated at the Iowa State University Lauren Christian Swine Research and Demonstration Farm near Atlantic, IA. The gestation systems were 1) individual gestation crates in a mechanically ventilated, partially slatted floor, manure flush confinement building (CRATE); and 2) group pens in deep-bedded, naturally ventilated hoop structures (HOOP). The HOOP sows were fed with individual feed stalls.
The sows were artificially inseminated in a confinement breeding barn with slatted floors and were later moved to their assigned gestation housing treatment. Sows included in the study continued in the same gestation housing their entire time at the farm. All first-litter gilts were gestated in individual gestation crates to minimize sow size differential in the groups. There were 35 sows per group in the HOOP barns. Farrowing occurred every 2 weeks on a year-round basis. All sows were fed 4.5 lb/day and increased to 6 lb/day during the last trimester of gestation. During the winter, HOOP sows were fed 25% more and CRATE sows were fed 5% more.
Reproductive performance was summarized for 493 litters during the period March 2001 to September 2003. This is a progress report of a continuing study. Preliminary trends were a shorter wean-to-breed interval, 0.5 more live pigs born per litter, and 0.5 more pigs weaned/sow/year for HOOP sows compared with CRATE sows. Higher percentages of stillborn and mummied pigs were observed in the HOOP sows compared with the CRATE sows. Slightly lower pre-wean mortality and sow culling rates occurred in the CRATE sows as compared with HOOP sows, with similar sow mortality rates for both groups. The preliminary data suggests that gestating sows can be housed in deep-bedded hoop barns equipped with individual feeding stalls and achieve results comparable to individual crated gestation systems
Light noble gas composition of different solar wind regimes: results from genesis
The Genesis mission provided samples of solar wind
(SW) from different regions on the Sun. These SW regime samples are
important in understanding fractionation processes upon formation and
acceleration of the SW to ultimately deduce solar composition from SW
values. We present He and Ne isotopic and elemental compositions of the
bulk SW (SW of entire collection period) and the 3 major SW regimes: slow
(from the ecliptic plane, emanating from above streamers), fast (emanating
from coronal holes), and coronal mass ejections (CME). At the conference
we will also present Ar data
Mass-fractionation induced by the Genesis solar wind concentrator: Analysis of neon isotopes by UV laser ablation
The solar wind (SW) concentrator, a key instrument onboard the
Genesis mission, was designed to provide larger fluences of implanted SW
for precise isotope analyses of oxygen and nitrogen [1]. SW ions in the mass
range 4â28 amu were accelerated and focused on a âconcentrator targetâ by
an electrostatic mirror. This concentration process caused some instrumental
mass fractionation of the implanted SW ions as function of the radial position
on the target. Correction of this fractionation will be based on a combination
of the measured radial fractionation of Ne isotopes with results of simulations
of the implantation process using the actual performance of the concentrator
and the SW conditions during exposure. Here we present He and Ne
abundance and Ne isotopic composition data along one arm of the gold cross
that framed the 4 concentrator subtargets
Syntaxin 1 Ser14 phosphorylation is required for nonvesicular dopamine release
Amphetamine (AMPH) is a psychostimulant that is commonly abused. The stimulant properties of AMPH are associated with its ability to increase dopamine (DA) neurotransmission. This increase is promoted by nonvesicular DA release mediated by reversal of DA transporter (DAT) function. Syntaxin 1 (Stx1) is a SNARE protein that is phosphorylated at Ser(14) by casein kinase II. We show that Stx1 phosphorylation is critical for AMPH-induced nonvesicular DA release and, in Drosophila melanogaster, regulates the expression of AMPH-induced preference and sexual motivation. Our molecular dynamics simulations of the DAT/Stx1 complex demonstrate that phosphorylation of these proteins is pivotal for DAT to dwell in a DA releasing state. This state is characterized by the breakdown of two key salt bridges within the DAT intracellular gate, causing the opening and hydration of the DAT intracellular vestibule, allowing DA to bind from the cytosol, a mechanism that we hypothesize underlies nonvesicular DA release
Controls on Microbial and Oolitic Carbonate Sedimentation and Stratigraphic Cyclicity Within a Mixed Carbonate-Siliciclastic System: Upper Cambrian Wilberns Formation, Llano Uplift, Mason County, Texas, USA
The upper Cambrian Wilberns Formation in central Texas records deposition on a low-gradient shelf within a mixed carbonateâsiliciclastic tidal-flat system that changes offshore to subtidal shelf and open-marine oolitic skeletal shoals with large microbial mounds. Siliciclastic sediment is interpreted to have been delivered to the tidal flat by aeolian processes because of the narrow range in grain size and paucity of clay. Tidal influence is dominant as evidenced by reversing currents and desiccation on the tidal flat, and megaripples with reversing current indicators in offshore shoals. Intraclastic conglomerates were deposited in broad channels on the tidal flats during storm surges. Microbialite deposition is interpreted to be controlled by accommodation favouring amalgamated thin biostromes developed in the tidal flat vs. larger mounds with greater synoptic relief in the offshore, and current energy resulting in preferential elongation of offshore mounds in a NEâSW orientation. Intertidal mounds and biostromes grew in the presence of significant siliciclastic flux and trapped it within their structure, whereas offshore large buildups incorporated little siliciclastic component. Oolite and skeletal grainstone formed in tide agitated shoals associated with large subtidal microbial mounds. Storms extensively recycled and redistributed skeletal and oolitic sands from the offshore shoals across the shelf as thin sand sheets. Spatial mixing of siliciclastic and carbonate sediment occurred across the tidal flat and shelf. Low-frequency and intermediate-frequency stratigraphic cycles were driven by shifts in the shoreline and changes in rate of siliciclastic flux in response to relative sea-level fluctuation. Random facies stacking and the lack of metre-scale cyclicity are interpreted to reflect stratigraphic incompleteness and an episodic signal introduced by storms
Encounters with the moral economy of water: convergent evolution in Valencia
[EN] This article presents the results of comparative fieldwork on the huerta of Valencia in Spain, a successful community-managed irrigation system of medium scale, one governed collectively by thousands of small farmers organized into 10 autonomous but highly interdependent irrigator groups. The study tested a model identified previously in research on successful systems of much smaller scale in Peru, a set of principles of operation that, when affirmed by farmers and obeyed as collective-choice rules, interact to create equity among water rights and transparency in water use in an unusual way. The authors show that a nearly identical set are at work in all 10 communities of Valencia, revealing the unique manner in which these work together to promote successful and sustainable cooperation, both within and between the user groups, and arguing that their presence in Spain and the Andes is indicative, not of diffusion from one continent to another, but of independent invention. These principles together laid the foundations for separate Andean and Islamic hydraulic traditions, which were often manifested locally in robust and equitable systems of the same general type, here called the moral economy of water. This kind of communal system appears to have emerged repeatedly, and often independently, in a great many other locales and settings throughout the world; its adaptive dynamics are shown to be of great relevance to small farmers today as they face the growing scarcity of water being induced by population growth and by climate change.Trawick, P.; Ortega Reig, MV.; Palau-Salvador, G. (2014). Encounters with the moral economy of water: convergent evolution in Valencia. Wiley Interdisciplinary Reviews: Water. 1(1):87-110. doi:10.1002/wat2.1008S871101
Argon and neon in Genesis aluminum-coated sapphire collectors from regime arrays
Here we report Ar results from the aluminum on sapphire (AloS) bulk regime samples, from which Ne results were obtained [1]. Ar measurements from other regimes are in progress
Preliminary studies of Xe and Kr from the Genesis polished aluminium collector
Low solar wind (SW) abundances of Xe and Kr require
a large collector area to provide measurable quantities of these rare gases.
Originally we planned to use large areas of Al on Sapphire (AloS) collectors,
but the hard landing of Genesis fractured these collectors, changing our initial
plans. The only large, relatively intact, surface exposed to SW was the
kidney-shaped polished aluminum T6-6061 alloy (AlK) designed to serve as
a thermal shield rather than a SW collector. Here we describe what has been
done and the problems remaining to be solved for optimized Xe and Kr
abundances and isotopic compositions from the AlK
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Open science, communal culture, and womenâs participation in the movement to improve science
Science is undergoing rapid change with the movement to improve science focused largely on reproducibility/replicability and open science practices. This moment of changeâin which science turns inward to examine its methods and practicesâprovides an opportunity to address its historic lack of diversity and noninclusive culture. Through network modeling and semantic analysis, we provide an initial exploration of the structure, cultural frames, and womenâs participation in the open science and reproducibility literatures (n = 2,926 articles and conference proceedings). Network analyses suggest that the open science and reproducibility literatures are emerging relatively independently of each other, sharing few common papers or authors. We next examine whether the literatures differentially incorporate collaborative, prosocial ideals that are known to engage members of underrepresented groups more than independent, winner-takes-all approaches. We find that open science has a more connected, collaborative structure than does reproducibility. Semantic analyses of paper abstracts reveal that these literatures have adopted different cultural frames: open science includes more explicitly communal and prosocial language than does reproducibility. Finally, consistent with literature suggesting the diversity benefits of communal and prosocial purposes, we find that women publish more frequently in high-status author positions (first or last) within open science (vs. reproducibility). Furthermore, this finding is further patterned by team size and time. Women are more represented in larger teams within reproducibility, and womenâs participation is increasing in open science over time and decreasing in reproducibility. We conclude with actionable suggestions for cultivating a more prosocial and diverse culture of science
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