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West Baraboo, WI, United States

Jagadamma S.,Oak Ridge National Laboratory | Steinweg J.M.,Oak Ridge National Laboratory | Steinweg J.M.,University of Wisconsin Baraboo Sauk County | Mayes M.A.,Oak Ridge National Laboratory | And 2 more authors.
Biology and Fertility of Soils | Year: 2014

There have been increasing efforts to understand the dynamics of organic carbon (OC) associated with measurable fractions of bulk soil. We compared the decomposition of native OC (native C) with that of an added substrate (glucose) on physically separated fractions of a diverse suite of soils. Five soil orders were selected from four contrasting climate zones (Mollisol from temperate, Ultisol and Oxisol from tropics, Andisol from sub-arctic, and Gelisol from arctic region). Soils from the A horizon were fractionated into particulate OC (POC) and mineral-associated OC (MOC) by a size-based method. Fractions were incubated at 20 °C and 50 % water-holding capacity in the dark after the addition of unlabeled d-glucose (0.4 mg C g-1 fraction) and U-14C glucose (296 Bq g-1 fraction). Respiration of glucose 14C indicated 64 to 84 % of added glucose 14C which was respired from POC and 62 to 70 % from MOC within 150 days of incubation, with more than half of the cumulative respiration occurring within 4 days. Native C respiration varied widely across fractions: 12 to 46 % of native C was respired from POC and 3 to 10 % was respired from MOC fractions. This suggested that native C was more stabilized on the MOC than on the POC, but respiration from the added glucose was generally similar for MOC and POC fractions. Our study suggests a fundamental difference between the behavior of freshly added C and native C from MOC and POC fractions of soils. © 2013 Springer-Verlag Berlin Heidelberg. Source

Jagadamma S.,Oak Ridge National Laboratory | Mayes M.A.,Oak Ridge National Laboratory | Steinweg J.M.,Oak Ridge National Laboratory | Steinweg J.M.,University of Wisconsin Baraboo Sauk County | Schaeffer S.M.,University of Tennessee at Knoxville
Biogeosciences | Year: 2014

The rate and extent of decomposition of soil organic carbon (SOC) is dependent, among other factors, on substrate chemistry and microbial dynamics. Our objectives were to understand the influence of substrate chemistry on microbial decomposition of carbon (C), and to use model fitting to quantify differences in pool sizes and mineralization rates. We conducted an incubation experiment for 270 days using four uniformly labeled 14C substrates (glucose, starch, cinnamic acid and stearic acid) on four different soils (a temperate Mollisol, a tropical Ultisol, a sub-arctic Andisol, and an arctic Gelisol). The 14C labeling enabled us to separate CO2 respired from added substrates and from native SOC. Microbial gene copy numbers were quantified at days 4, 30 and 270 using quantitative polymerase chain reaction (qPCR). Substrate C respiration was always higher for glucose than other substrates. Soils with cinnamic and stearic acid lost more native SOC than glucose- and starch-amended soils. Cinnamic and stearic acid amendments also exhibited higher fungal gene copy numbers at the end of incubation compared to unamended soils. We found that 270 days were sufficient to model the decomposition of simple substrates (glucose and starch) with three pools, but were insufficient for more complex substrates (cinnamic and stearic acid) and native SOC. This study reveals that substrate quality exerts considerable control on the microbial decomposition of newly added and native SOC, and demonstrates the need for multi-year incubation experiments to constrain decomposition parameters for the most recalcitrant fractions of SOC and complex substrates. © Author(s) 2014. CC Attribution 3.0 License. Source

Tom Lorenz O.,University of New Orleans | Horne B.D.,Institute for Conservation Research | Anderson N.J.,University of Wisconsin Baraboo Sauk County | Cheek A.O.,Southeastern Louisiana University
Herpetological Conservation and Biology | Year: 2011

Reproductive cycles in temperate zone colubrid snakes are generally characterized by summer spermatogenesis (postnuptial) in males and spring vitellogenesis (Type I) in females. Watersnakes and gartersnakes in southern North America have shorter hibernation periods than confamilial northern species and potentially different timing of hormonal cues regulating gametogenesis. We studied the reproductive cycles of male and female Broad Banded Watersnakes (Nerodia fasciata confluens) to uncover whether hormone cycles are more similar to closely related northern natricine species or to more distantly related southern colubrids. We collected N. f. confluens from southeastern Louisiana and maintained them in outdoor enclosures. The first experiment quantified circulating sex steroid hormones, follicle growth, and presence or absence of sperm each month from February 2000 to February 2001. The second experiment measured the same variables weekly during the spring breeding season, from early April 2001 to late June 2001. Male androgen concentrations were elevated in the fall and the spring. Female estradiol-17β was elevated in the spring only. Ovarian follicle growth began in early May, after mating. The male reproductive cycle was classified as postnuptial spermatogenesis and the female cycle as Type I vitellogenesis; rapid follicle growth in the spring. Nerodia f. confluens has a reproductive pattern more similar to other southern temperate colubrids than to its more closely related northern temperate natricines, suggesting that local climate has a stronger influence on reproductive timing than phylogeny. © 2011. O. Tom Lorenz. All rights reserved. Source

Murray D.,University of Wisconsin Baraboo Sauk County
Journal of Medicine and Philosophy | Year: 2011

In 2007, Massachusetts instituted a universal coverage health plan that requires all citizens to purchase insurance. I argue that there is nothing wrong in principle with the use of an individual mandate to force citizens to secure health insurance. I argue that state neutrality is not tenable on this issue. Then I proceed to show that even if state neutrality were viable, it is not a violation of state neutrality (thought of as neutrality of intent) to force citizens to insure themselves with the primary purpose of securing the normative good of health. I adapt recent work on universal medical coverage to demonstrate that such a mandate is in keeping with several principles of fairness shared in liberal democratic societies. This argument not only applies to the Massachusetts plan but likely to any other health care coverage schemes using individual mandates in the US political context, including recently passed federal health care reform measures. However, even though the Massachusetts plan may provide increased access to health care for many, there are still legitimate worries that it currently places disproportionate financial burdens on the working poor and thus will need refinement. © The Author 2011. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. Source

The Twenty-First Century will pose many challenges for our students. One of the main scientific and humankind challenges will be how we will feed, reliably, cheaply, and healthfully, a world whose human population continues to rapidly grow. In this Twenty-First Century Issues course about Food, we give our students an opportunity to see the connectivity of this science problem from a multi-disciplinary approach. In designing this course about Food around three connecting knowledge areas - the science, the ethics, and the practical - our goals are to provide students the tools to be able to comprehend the complexity of the situation, to have students begin to trust themselves to seek answers, and to inspire students to come away from our course with the mindset that no problem is too large to do something about. © 2013 American Chemical Society. Source

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