348 research outputs found
Effects of Ralgro Implants on Growth, Sexual Development, Carcass Characteristics, and Eating Quality of Bulls Implanted From Birth to Slaughter
Growth, performance, sexual development, carcass characteristics, and eating quality were evaluated on 40 fall-born Angus bulls. Twenty of the bulls were implanted five times with Ralgro at an average interval of 106 days, beginning near birth. The other 20 bulls served as nonimplanted controls. Bull calves remained with their dams on native southeast Kansas pasture for an average of 320 days; they were then allotted to drylot pens (feedlot beginning) and placed on a 75% concentrate ration. Bulls from each treatment were fed to target weights of 1000 and 1100 pounds, and then slaughtered. Ralgro implanting increased average daily gain 6.6% over that of the controls from birth to the feedlot beginning, and 9.4% from the feedlot beginning to the first slaughter endpoint (196 days on feed). Feed efficiency was improved 8.2%, with implanting when the first group of implanted and control bulls were slaughtered (196 and 231 days on feed, respectively). Implanting reduced semen quality, reduced the number of bulls producing semen, and depressed the development of reproductive organs. Sex drive was unaffected by implanting. Implanting resulted in fatter carcasses and tended to increase yield grades, but did not affect final quality grades. Lean from control carcasses tended to be firmer and have a finer texture, but color was not affected by implanting. Loineye steaks from implanted bulls were significantly more tender, as judged by taste panel ratings and by Warner-Bratzler shear forces
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Language support for immigrant children: a study of state schools in the UK and US
In recent decades, immigrants, refugees and asylum seekers have sought a new way of life in large numbers, often leaving their countries of origin behind in search of places that offer a better way of life. The purpose of this study was to investigate how elementary and middle school students in state schools in Reading, England (primarily speakers of Asian languages), and Richmond, Virginia (primarily speakers of Spanish), were supported academically, when most children’s first language was not English. The authors were interested in exploring whether or not there were cultural or structural differences in the way each country helped or hindered these students as they progressed through the school systems. Three UK schools in a district of approximately 100,000 and three US schools in a district of approximately 250,000 were the focus of this exploration from 2000 to 2003. Findings indicated that there were cultural and legislative differences and similarities. Teachers and administrators in both countries attempted to provide services with limited and sometimes diminishing resources. Community support varied based on resources, attitudes toward various ethnic groups, and the coping strategies adopted by these groups in their new environments. Marked differences appeared with regard to the manner in which assessments took place and how the results were made available to the public
Toward Rational Design of Metal-Organic Frameworks for Sensing Applications: Efficient Calculation of Adsorption Characteristics in Zero Loading Regime
High-Fat Diet with Acyl-Ghrelin Treatment Leads to Weight Gain with Low Inflammation, High Oxidative Capacity and Normal Triglycerides in Rat Muscle
Obesity is associated with muscle lipid accumulation. Experimental models suggest that inflammatory cytokines, low mitochondrial oxidative capacity and paradoxically high insulin signaling activation favor this alteration. The gastric orexigenic hormone acylated ghrelin (A-Ghr) has antiinflammatory effects in vitro and it lowers muscle triglycerides while modulating mitochondrial oxidative capacity in lean rodents. We tested the hypothesis that A-Ghr treatment in high-fat feeding results in a model of weight gain characterized by low muscle inflammation and triglycerides with high muscle mitochondrial oxidative capacity. A-Ghr at a non-orexigenic dose (HFG: twice-daily 200-µg s.c.) or saline (HF) were administered for 4 days to rats fed a high-fat diet for one month. Compared to lean control (C) HF had higher body weight and plasma free fatty acids (FFA), and HFG partially prevented FFA elevation (P<0.05). HFG also had the lowest muscle inflammation (nuclear NFkB, tissue TNF-alpha) with mitochondrial enzyme activities higher than C (P<0.05 vs C, P = NS vs HF). Under these conditions HFG prevented the HF-associated muscle triglyceride accumulation (P<0.05). The above effects were independent of changes in redox state (total-oxidized glutathione, glutathione peroxidase activity) and were not associated with changes in phosphorylation of AKT and selected AKT targets. Ghrelin administration following high-fat feeding results in a novel model of weight gain with low inflammation, high mitochondrial enzyme activities and normalized triglycerides in skeletal muscle. These effects are independent of changes in tissue redox state and insulin signaling, and they suggest a potential positive metabolic impact of ghrelin in fat-induced obesity
Proliferation of Hydroelectric Dams in the Andean Amazon and Implications for Andes-Amazon Connectivity
Due to rising energy demands and abundant untapped potential, hydropower projects are rapidly increasing in the Neotropics. This is especially true in the wet and rugged Andean Amazon, where regional governments are prioritizing new hydroelectric dams as the centerpiece of long-term energy plans. However, the current planning for hydropower lacks adequate regional and basin-scale assessment of potential ecological impacts. This lack of strategic planning is particularly problematic given the intimate link between the Andes and Amazonian flood plain, together one of the most species rich zones on Earth. We examined the potential ecological impacts, in terms of river connectivity and forest loss, of the planned proliferation of hydroelectric dams across all Andean tributaries of the Amazon River. Considering data on the full portfolios of existing and planned dams, along with data on roads and transmission line systems, we developed a new conceptual framework to estimate the relative impacts of all planned dams. There are plans for 151 new dams greater than 2 MW over the next 20 years, more than a 300% increase. These dams would include five of the six major Andean tributaries of the Amazon. Our ecological impact analysis classified 47% of the potential new dams as high impact and just 19% as low impact. Sixty percent of the dams would cause the first major break in connectivity between protected Andean headwaters and the lowland Amazon. More than 80% would drive deforestation due to new roads, transmission lines, or inundation. We conclude with a discussion of three major policy implications of these findings. 1) There is a critical need for further strategic regional and basin scale evaluation of dams. 2) There is an urgent need for a strategic plan to maintain Andes-Amazon connectivity. 3) Reconsideration of hydropower as a low-impact energy source in the Neotropics
The TEXES Survey For H2 Emission From Protoplanetary Disks
We report the results of a search for pure rotational molecular hydrogen
emission from the circumstellar environments of young stellar objects with
disks using the Texas Echelon Cross Echelle Spectrograph (TEXES) on the NASA
Infrared Telescope Facility and the Gemini North Observatory. We searched for
mid-infrared H2 emission in the S(1), S(2), and S(4) transitions. Keck/NIRSPEC
observations of the H2 S(9) transition were included for some sources as an
additional constraint on the gas temperature. We detected H2 emission from 6 of
29 sources observed: AB Aur, DoAr 21, Elias 29, GSS 30 IRS 1, GV Tau N, and HL
Tau. Four of the six targets with detected emission are class I sources that
show evidence for surrounding material in an envelope in addition to a
circumstellar disk. In these cases, we show that accretion shock heating is a
plausible excitation mechanism. The detected emission lines are narrow (~10
km/s), centered at the stellar velocity, and spatially unresolved at scales of
0.4 arcsec, which is consistent with origin from a disk at radii 10-50 AU from
the star. In cases where we detect multiple emission lines, we derive
temperatures > 500 K from ~1 M_earth of gas. Our upper limits for the
non-detections place upper limits on the amount of H2 gas with T > 500 K of
less than a few Earth masses. Such warm gas temperatures are significantly
higher than the equilibrium dust temperatures at these radii, suggesting that
the gas is decoupled from the dust in the regions we are studying and that
processes such as UV, X-ray, and accretion heating may be important.Comment: 24 pages, 16 figures, 5 tables, ApJ accepte
The Io, Europa and Ganymede auroral footprints at Jupiter in the ultraviolet: positions and equatorial lead angles
Jupiter's satellite auroral footprints are a consequence of the interaction
between the Jovian magnetic field with co-rotating iogenic plasma and the
Galilean moons. The disturbances created near the moons propagate as Alfv\'en
waves along the magnetic field lines. The position of the moons is therefore
"Alfv\'enically" connected to their respective auroral footprint. The angular
separation from the instantaneous magnetic footprint can be estimated by the
so-called lead angle. That lead angle varies periodically as a function of
orbital longitude, since the time for the Alfv\'en waves to reach the Jovian
ionosphere varies accordingly. Using spectral images of the Main Alfv\'en Wing
auroral spots collected by Juno-UVS during the first forty-three orbits, this
work provides the first empirical model of the Io, Europa and Ganymede
equatorial lead angles for the northern and southern hemispheres. Alfv\'en
travel times between the three innermost Galilean moons to Jupiter's northern
and southern hemispheres are estimated from the lead angle measurements. We
also demonstrate the accuracy of the mapping from the Juno magnetic field
reference model (JRM33) at the completion of the prime mission for M-shells
extending to at least 15RJ . Finally, we shows how the added knowledge of the
lead angle can improve the interpretation of the moon-induced decametric
emissions.Comment: 20 pages, 8 figures, Accepted for publication in Journal of
Geophysical Research: Space Physics on 20 April 202
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