Seasonal Soil CO2 Flux Under Big Sagebrush (Artemisia tridentata Nutt.)

Soil respiration is a major contributor to atmospheric CO2, but accurate landscape-scale estimates of soil CO2 flux for many ecosystems including shrublands have yet to be established. We began a project to measure, with high spatial and temporal resolution, soil CO2 flux in a stand (11 x 25 m area) of big sagebrush (Artemisia tridentata Nutt.) at the Logan, Utah, Forestry Sciences Laboratory. Beginning on Nov. 1, 2009, hourly soil CO2 flux measurements were made at a single location in the stand using the Li-Cor LI-8100 soil CO2 flux instrument and 20-cm long-term chamber. Beginning in April, 2010, monthly soil CO2 flux measurements were made on a grid of 11 locations within the stand using the LI- 8100 equipped with the 20-cm survey chamber. Hourly soil temperature (10-cm depth) and volumetric soil water content data were also collected. Soil CO2 flux, temperature, and water content were highly temporally and spatially variable in the sagebrush stand. Mean (std dev) soil CO2 flux, temperature, and water content for the measurement period (November 1, 2009 - October 31, 2010) were 0.96 (0.81) umol m-2 s-1, 10.59 (10.11) deg C, and 0.101 (0.062) m3 m-3, respectively. Calculated annual soil CO2 flux obtained by summing all the hourly measurements was 328 g C m-2 y-1. For semi-arid or arid sites where precipitation is less than evapotranspiration, measured total annual soil CO2 flux will be less than the potential maximum because of dry season suppression of soil respiration when soil water content is very low

Agile methods for agile universities

We explore a term, Agile, that is being used in various workplace settings, including the management of universities. The term may have several related but slightly different meanings. Agile is often used in the context of facilitating more creative problem-solving and advocating for the adoption, design, tailoring and continual updating of more innovative organizational processes. We consider a particular set of meanings of the term from the world of software development. Agile methods were created to address certain problems with the software development process. Many of those problems have interesting analogues in the context of universities, so a reflection on agile methods may be a useful heuristic for generating ideas for enabling universities to be more creative

Using an epiphytic moss to identify previously unknown sources of atmospheric cadmium pollution

Urban networks of air-quality monitors are often too widely spaced to identify sources of air pollutants, especially if they do not disperse far from emission sources. The objectives of this study were to test the use of moss bioindicators to develop a fine-scale map of atmospherically-derived cadmium and to identify the sources of cadmium in a complex urban setting.We collected 346 samples of the moss Orthotrichum lyellii from deciduous trees in December, 2013 using a modified randomized grid-based sampling strategy across Portland, Oregon.We estimated a spatial linear model of moss cadmium levels and predicted cadmium on a 50 m grid across the city. Cadmium levels in moss were positively correlated with proximity to two stained-glass manufacturers, proximity to the Oregon– Washington border, and percent industrial land in a 500 m buffer, and negatively correlated with percent residential land in a 500 m buffer. The maps showed very high concentrations of cadmium around the two stained-glass manufacturers, neither of which were known to environmental regulators as cadmium emitters. In addition, in response to our findings, the Oregon Department of Environmental Quality placed an instrumental monitor 120 m from the larger stained-glass manufacturer in October, 2015. The monthly average atmospheric cadmium concentration was 29.4 ng/m3,which is 49 times higher than Oregon\u27s benchmark of 0.6 ng/m3, and high enough to pose a health risk from even short-term exposure. Both stained-glass manufacturers voluntarily stopped using cadmium after the monitoring results were made public, and the monthly average cadmium levels precipitously dropped to 1.1 ng/m3 for stained-glass manufacturer #1 and 0.67 ng/m3 for stained-glass manufacturer #2

Using an epiphytic moss to identify previously unknown sources of atmospheric cadmium pollution

Urban networks of air-quality monitors are often too widely spaced to identify sources of air pollutants, especially if they do not disperse far from emission sources. The objectives of this study were to test the use of moss bioindicators to develop a fine-scale map of atmospherically-derived cadmium and to identify the sources of cadmium in a complex urban setting.We collected 346 samples of the moss Orthotrichum lyellii from deciduous trees in December, 2013 using a modified randomized grid-based sampling strategy across Portland, Oregon.We estimated a spatial linear model of moss cadmium levels and predicted cadmium on a 50 m grid across the city. Cadmium levels in moss were positively correlated with proximity to two stained-glass manufacturers, proximity to the Oregon– Washington border, and percent industrial land in a 500 m buffer, and negatively correlated with percent residential land in a 500 m buffer. The maps showed very high concentrations of cadmium around the two stained-glass manufacturers, neither of which were known to environmental regulators as cadmium emitters. In addition, in response to our findings, the Oregon Department of Environmental Quality placed an instrumental monitor 120 m from the larger stained-glass manufacturer in October, 2015. The monthly average atmospheric cadmium concentration was 29.4 ng/m3,which is 49 times higher than Oregon\u27s benchmark of 0.6 ng/m3, and high enough to pose a health risk from even short-term exposure. Both stained-glass manufacturers voluntarily stopped using cadmium after the monitoring results were made public, and the monthly average cadmium levels precipitously dropped to 1.1 ng/m3 for stained-glass manufacturer #1 and 0.67 ng/m3 for stained-glass manufacturer #2

Genetic Interactions in Zebrafish Midline Development

AbstractMutational analyses have shown that the genesno tail(ntl, Brachyuryhomolog),floating head(flh,aNothomeobox gene), andcyclops(cyc) play direct and essential roles in the development of midline structures in the zebrafish. In bothntlandflhmutants a notochord does not develop, and incycmutants the floor plate is nearly entirely missing. We made double mutants to learn how these genes might interact. Midline development is disrupted to a greater extent incyc;flhdouble mutants than in eithercycorflhsingle mutants; their effects appear additive. Both the notochord and floor plate are completely lacking, and other phenotypic disturbances suggest that midline signaling functions are severely reduced. On the other hand, trunk midline defects inflh;ntldouble mutants are not additive, but are most often similar to those inntlsingle mutants. This finding reveals that loss ofntlfunction can suppress phenotypic defects due to mutation atflh,and we interpret it to mean that the wild-type allele ofntl(ntl+) functions upstream toflhin a regulatory hierarchy. Loss of function ofntlalso strongly suppresses the floor plate deficiency incycmutants, for we found trunk floor plate to be present incyc;ntldouble mutants. From these findings we propose thatntl+plays an early role in cell fate choice at the dorsal midline, mediated by the Ntl protein acting to antagonize floor plate development as well as to promote notochord development

Disposition of Federally Owned Surpluses

PDZ domains are scaffolding modules in protein-protein interactions that mediate numerous physiological functions by interacting canonically with the C-terminus or non-canonically with an internal motif of protein ligands. A conserved carboxylate-binding site in the PDZ domain facilitates binding via backbone hydrogen bonds; however, little is known about the role of these hydrogen bonds due to experimental challenges with backbone mutations. Here we address this interaction by generating semisynthetic PDZ domains containing backbone amide-to-ester mutations and evaluating the importance of individual hydrogen bonds for ligand binding. We observe substantial and differential effects upon amide-to-ester mutation in PDZ2 of postsynaptic density protein 95 and other PDZ domains, suggesting that hydrogen bonding at the carboxylate-binding site contributes to both affinity and selectivity. In particular, the hydrogen-bonding pattern is surprisingly different between the non-canonical and canonical interaction. Our data provide a detailed understanding of the role of hydrogen bonds in protein-protein interactions

Nifedipin ublažava djelovanje kokaina na enzimsku aktivnost u mozgu i jetri te smanjuje njegovo izlučivanje putem mokraće

The aim of this study was to see how nifedipine counters the effects of cocaine on hepatic and brain enzymatic activity in rats and whether it affects urinary excretion of cocaine. Male Wistar rats were divided in four groups of six: control, nifedipine group (5 mg kg-1 i.p. a day for five days); cocaine group (15 mg kg-1 i.p. a day for five days), and the nifedipine+cocaine group. Twenty-four hours after the last administration, we measured neuronal nitric oxide synthase (nNOS) activity in the brain and cytochrome P450 quantity, ethylmorphine-N-demethylase, and anilinehydroxylase activity in the liver. Urine samples were collected 24 h after the last cocaine and cocaine+nifedipine administration. Urinary cocaine concentration was determined using the GC/MS method. Cocaine administration increased brain nNOS activity by 55 % (p<0.05) in respect to control, which indicates the development of tolerance and dependence. In the combination group, nifedipine decreased the nNOS activity in respect to the cocaine-only group. In the liver, cocaine significantly decreased and nifedipine significantly increased cytochrome P450, ethylmorphine-N-demethylase, and anilinehydroxylase in respect to control. In combination, nifedipine successfully countered cocaine effects on these enzymes. Urine cocaine excretion in the cocaine+nifedipine group significantly dropped (by 35 %) compared to the cocaine-only group. Our results have confirmed the effects of nifedipine against cocaine tolerance and development of dependence, most likely due to metabolic interactions between them.Cilj je ovoga istraživanja bio utvrditi kako nifedipin ublažava djelovanje kokaina na enzimsku aktivnost u mozgu i jetri Wistar štakora te utječe li na njegovo izlučivanje putem mokraće. Mužjaci su podijeljeni u četiri skupine po šest jedinki: kontrolnu skupinu, nifedipinsku skupinu koja je pet dana intraperitonealno primala nifedipin u dozi od 5 mg kg-1; skupinu koja je pet dana primala kokain u dozi od 15 mg kg-1 na dan te skupinu koja je zajedno primala nifedipin i kokain u odgovarajućim dozama. Dvadeset i četiri sata nakon posljednje doze izmjerena je enzimska aktivnost sintaze dušičnoga oksida (nNOS) u mozgu, razina citokroma P450 te aktivnosti enzima etilmorfi n-N-demetilaze i anilinhidroksilaze u jetri štakora. Uzorci mokraće prikupljeni su 24 sata nakon posljednje doze kokaina odnosno kombinacije nifedipina i kokaina. Koncentracija kokaina u mokraći izmjerena je s pomoću vezanog sustava plinske kromatografi je i spektrometrije masa. Kokain je povećao aktivnost nNOS-a u mozgu za 55 % (p<0,05) u odnosu na kontrolnu skupinu, što upućuje na stvaranje tolerancije i ovisnosti. U kombiniranoj skupini nifedipin je značajno smanjio aktivnost nNOS-a u odnosu na skupinu koja je primila samo kokain. Kokain je značajno snizio, a nifedipin značajno povisio razinu citokroma P450 u jetri te aktivnost etilmorfi n-N-demetilaze i anilinhidroksilaze u odnosu na kontrolnu skupinu. U kombiniranoj skupini nifedipin je uspješno ublažio djelovanje kokaina na aktivnost spomenutih enzima. Izlučivanje kokaina putem mokraće u kombiniranoj skupini bilo je značajno manje (35 %) nego u skupini koja je primala samo kokain. Ovi rezultati potvrđuju da nifedipin štiti od djelovanja kokaina i stvaranja ovisnosti, najvjerojatnije zbog interakcija u metabolizmu dvaju spojeva