Riverine Carbon Cycling as a Function of Seasonality

Montana has one of the most dynamic climate regimes in all of the United States, with seasonal changes spanning a large range of temperatures.  In Montana, we depend on water originating from snow and glacial melt. These freshwater ecosystems are considered to be some of the most vulnerable to climate change on Earth.  Glacially fed ecosystems are unique habitats for a vast array of life and geochemical processes, including carbon cycling. In order to study carbon cycling in environments vulnerable to change, an interdisciplinary approach including biogeochemical analyses of river DOM production and external allochthonous inputs is necessary to evaluate the impacts of climate change.  The overarching hypothesis for this work is: Seasonal changes in Montana rivers will cause shifts in carbon cycling as ecosystems respond to changes in temperature.  Unlike our initial hypothesis that the amount of sunlight and temperature would play a bigger role in what was happening, the time of the year was much more significant. In Big Sky OC levels in June for the sunny and canopy covered reaches were similar, 1.24 and 1.23 mg C/L, respectively; whereas at the end of July OC in the sunny reach was 0.42 mg C/Land the canopy cover reach was 0.955 mg C/L. The same trend is seen for the urban location in Bozeman. Cell abundance in the reaches followed similar trends, which were not solely based on temperature

Transdisciplinarity Within the Academic Engineering Literature

Despite increased discourse around transdisciplinary (TD) research, there is a perception it has received less attention within engineering. This is significant if, as generally accepted, TD increases the societal value of research. This paper benchmarks TD engineering research against the broader TD literature, addressing the question: How do the characteristics of the academic engineering TD literature compare to the TD academic literature in general? We analyse the chronology, journals, and text of papers referencing TD within their abstract and compare this to papers that fall within the engineering subject area. The conclusions find that TD research is limited generally, and within engineering specifically. Historically, TD research focuses on sustainability challenges, a persistent trend within the general literature. Within engineering research, the focus of TD is wider and addresses operational and “grand challenge” problems. TD remains poorly defined and future work should focus on clarifying meaning within the engineering discipline

Specialized roles of human natural killer cell subsets in kidney transplant rejection

Background: Human natural killer (NK) cells are key functional players in kidney transplant rejection. However, the respective contributions of the two functionally distinct human NK cell subsets (CD56(bright) cytokine-producing vs. CD56(dim) cytotoxic effector) in episodes of allograft rejection remain uncertain, with current immunohistochemical methods unable to differentiate these discrete populations. We report the outcomes of an innovative multi-color flow cytometric-based approach to unequivocally define and evaluate NK cell subsets in human kidney allograft rejection.Methods: We extracted renal lymphocytes from human kidney transplant biopsies. NK cell subsets were identified, enumerated, and phenotyped by multi-color flow cytometry. Dissociation supernatants were harvested and levels of soluble proteins were determined using a multiplex bead-based assay.Results were correlated with the histopathological patterns in biopsies-no rejection, borderline cellular rejection, T cell-mediated rejection (TCMR), and antibody-mediated rejection (AMR). Results: Absolute numbers of only CD56(bright) NK cells were significantly elevated in TCMR biopsies. In contrast, both CD56(bright) and CD56(dim) NK cell numbers were significantly increased in biopsies with histopathological evidence of AMR. Notably, expression of the activation marker CD69 was only significantly elevated on CD56(dim) NK cells in AMR biopsies compared with no rejection biopsies, indicative of a pathogenic phenotype for this cytotoxic NK cell subset. In line with this, we detected significantly elevated levels of cytotoxic effector molecules (perforin, granzyme A, and granulysin) in the dissociation supernatants of biopsies with a histopathological pattern of AMR.Conclusions: Our results indicate that human NK cell subsets are differentially recruited and activated during distinct types of rejection, suggestive of specialized functional roles