45 research outputs found

    Transformative Learning and the 4-H Camp Counselor Experience in Minnesota

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    While many studies about the 4-H camping experience focus on youth who are campers, few studies examine the outcomes of the experience for counselors. This study examines the extent to which 4-H camp results in transformative learning for 4-H members who serve as camp counselors, examines the perceived changes that occur within counselors, and describes the factors and characteristics of camp that result in personal transformation. The population for this study was 2012 Minnesota 4-H camp counselors. Using the Transformative Learning and the Camp Experience Staff Member Survey, the results indicated that camp counselors experienced transformative learning. Major personal changes involved developing skills for working with children and exposure to new people, activities, and experiences. Factors leading to personal transformation included the opportunity to be role models and positively impact children, opportunities for leadership and challenge, and camp traditions. This study provides support for strong and intentional camp counseling experiences that can positively impact the individual, 4-H campers, and later, the communities in which these camp counselors reside

    Genetic Variance and Covariance Components for Feed Intake, Average Daily Gain, and Postweaning Gain in Growing Beef Cattle

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    Feed is the greatest cost for a beef cattle production enterprise. Data collection to determine feed efficiency of animals is also costly, because both gain and intake records are needed to calculate feed efficiency. Electronic intake monitoring systems such as GrowSafe or Insentec to collect feed intake data are expensive and thus limit the number of animals that can be tested. Scientists have worked to pinpoint optimal test durations for collecting both weight gain and feed intake records to lessen costs. A 70-day performance test is currently recommended for accurate calculation of efficiency, with growth data as the limiting factor. Research has suggested that a 35-day test is adequate to measure feed intake, but a test period of at least 70 days is suggested to measure gain with sufficient accuracy. The objective of this study was to estimate genetic parameters for growth and intake traits with particular attention to the relationship between on-test average daily gain (ADG) and national cattle evaluation postweaning gain (PWG). If the correlation between these two traits is strong, it could allow for the use of PWG as a proxy for ADG in the genetic evaluation of feed efficiency. This substitution would allow producers to reduce the length of the test required to measure feed intake accurately

    Continued glacial retreat linked to changing macronutrient supply along the West Antarctic Peninsula

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    At the West Antarctic Peninsula (WAP), continued atmospheric and oceanic warming is causing significant physical and biogeochemical changes to glaciers and the marine environment. We compare sediment sources and drivers of macronutrient distributions at two bays along the WAP during austral summer 2020, using radioactive radium and stable oxygen isotopes to trace sedimentary influences and quantify different freshwater inputs. In the Ryder Bay, where the Sheldon Glacier is marine-terminating, radium activities at the sediment-water interface indicate considerable benthic mixing. Using radium isotope activity gradients to resolve radium and macronutrient fluxes, we find buoyant meltwater proximal to the glacier drives vigorous mixing of sediment and entrainment of macronutrient deep waters, on the order of 2.0 × 105 mol d− 1 for nitrate. Conversely, in the Marian Cove, where the Fourcade Glacier terminates on land, low salinities and oxygen isotopes indicate a meltwater-rich surface layer <1 m thick and rich in sediment, and strong vertical mixing to the seafloor. A continued shift to land-terminating glaciers along the WAP may have a significant impact upon nutrient and sediment supply to the euphotic zone, with impacts upon primary productivity and carbon uptake efficiency. The future of primary production, carbon uptake, and food web dynamics is therefore linked to glacier retreat dy�namics in the many fjords along the WAP

    Cutaneous Bacteria of the Redback Salamander Prevent Morbidity Associated with a Lethal Disease

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    Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is an infectious disease that causes population declines of many amphibians. Cutaneous bacteria isolated from redback salamanders, Plethodon cinereus, and mountain yellow-legged frogs, Rana muscosa, inhibit the growth of Bd in vitro. In this study, the bacterial community present on the skin of P. cinereus individuals was investigated to determine if it provides protection to salamanders from the lethal and sub-lethal effects of chytridiomycosis. When the cutaneous bacterial community was reduced prior to Bd exposure, salamanders experienced a significantly greater decrease in body mass, which is a symptom of the disease, when compared to infected individuals with a normal bacterial community. In addition, a greater proportion of infected individuals with a reduced bacterial community experienced limb-lifting, a behavior seen only in infected individuals. Overall, these results demonstrate that the cutaneous bacterial community of P. cinereus provides protection to the salamander from Bd and that alteration of this community can change disease resistance. Therefore, symbiotic microbes associated with this species appear to be an important component of its innate skin defenses

    Within- and Among-Population Variation in Chytridiomycosis-Induced Mortality in the Toad Alytes obstetricans

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    Background Chytridiomycosis is a fungal disease linked to local and global extinctions of amphibians. Susceptibility to chytridiomycosis varies greatly between amphibian species, but little is known about between- and within-population variability. However, this kind of variability is the basis for the evolution of tolerance and resistance evolution to disease. Methodology/Principal Findings In a common garden experiment, we measured mortality after metamorphosis of Alytes obstetricans naturally infected with Batrachochytrium dendrobatidis. Mortality rates differed significantly among populations and ranged from 27 to 90%. Within populations, mortality strongly depended on mass at and time through metamorphosis. Conclusions/Significance Although we cannot rule out that the differences observed resulted from differences in skin microbiota, different pathogen strains or environmental effects experienced by the host or the pathogen prior to the start of the experiment, we argue that genetic differences between populations are a likely source of at least part of this variation. To our knowledge, this is the first study showing differences in survival between and within populations under constant laboratory conditions. Assuming that some of this intraspecific variation has a genetic basis, this may suggest that there is the potential for the evolution of resistance or tolerance, which might allow population persistence

    Do Frogs Get Their Kicks on Route 66? Continental U.S. Transect Reveals Spatial and Temporal Patterns of Batrachochytrium dendrobatidis Infection

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    The chytrid fungus Batrachochytrium dendrobatidis (Bd) has been devastating amphibians globally. Two general scenarios have been proposed for the nature and spread of this pathogen: Bd is an epidemic, spreading as a wave and wiping out individuals, populations, and species in its path; and Bd is endemic, widespread throughout many geographic regions on every continent except Antarctica. To explore these hypotheses, we conducted a transcontinental transect of United States Department of Defense (DoD) installations along U.S. Highway 66 from California to central Illinois, and continuing eastward to the Atlantic Seaboard along U.S. Interstate 64 (in sum from Marine Corps Base Camp Pendleton in California to Naval Air Station Oceana in Virginia). We addressed the following questions: 1) Does Bd occur in amphibian populations on protected DoD environments? 2) Is there a temporal pattern to the presence of Bd? 3) Is there a spatial pattern to the presence of Bd? and 4) In these limited human-traffic areas, is Bd acting as an epidemic (i.e., with evidence of recent introduction and/or die-offs due to chytridiomycosis), or as an endemic (present without clinical signs of disease)? Bd was detected on 13 of the 15 bases sampled. Samples from 30 amphibian species were collected (10% of known United States' species); half (15) tested Bd positive. There was a strong temporal (seasonal) component; in total, 78.5% of all positive samples came in the first (spring/early-summer) sampling period. There was also a strong spatial component—the eleven temperate DoD installations had higher prevalences of Bd infection (20.8%) than the four arid (<60 mm annual precipitation) bases (8.5%). These data support the conclusion that Bd is now widespread, and promote the idea that Bd can today be considered endemic across much of North America, extending from coast-to-coast, with the exception of remote pockets of naïve populations
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