Root-associated fungi and acquisitive root traits facilitate permafrost nitrogen uptake from long-term experimentally warmed tundra.

Root-associated fungi (RAF) and root traits regulate plant acquisition of nitrogen (N), which is limiting to growth in Arctic ecosystems. With anthropogenic warming, a new N source from thawing permafrost has the potential to change vegetation composition and increase productivity, influencing climate feedbacks. Yet, the impact of warming on tundra plant root traits, RAF, and access to permafrost N is uncertain.

Mycobiont contribution to tundra plant acquisition of permafrost-derived nitrogen.

As Arctic soils warm, thawed permafrost releases nitrogen (N) that could stimulate plant productivity and thus offset soil carbon losses from tundra ecosystems. Although mycorrhizal fungi could facilitate plant access to permafrost-derived N, their exploration capacity beyond host plant root systems into deep, cold active layer soils adjacent to the permafrost table is unknown. We characterized root-associated fungi (RAF) that colonized ericoid (ERM) and ectomycorrhizal (ECM) shrub roots and occurred below the maximum rooting depth in permafrost thaw-front soil in tussock and shrub tundra communities.

Pervasive Effects of Wildfire on Foliar Endophyte Communities in Montane Forest Trees.

Plants in all terrestrial ecosystems form symbioses with endophytic fungi that inhabit their healthy tissues. How these foliar endophytes respond to wildfires has not been studied previously, but is important given the increasing frequency and intensity of severe wildfires in many ecosystems, and because endophytes can influence plant growth and responses to stress. The goal of this study was to examine effects of severe wildfires on endophyte communities in forest trees, with a focus on traditionally fire-dominated, montane ecosystems in the southwestern USA.

Public speaking: creating presentations that are awe inspiring not yawn producing.

Many physicians want to be good platform speakers; however, few of us have the background and training necessary to be an outstanding public speaker. Yes, we all have slide decks and PowerPoint programs provided to us so that we can turn our backs to the audience and read the verbiage on the slides. But does that technique generate useful information to the audience? Or if speaking to a lay audience, does that kind of talk make the audience members get out their cell phones and call the office to make an appointment in our practice? Probably not.

To what extent are free testosterone (FT) values reproducible between the two Washingtons, and can calculated FT be used in lieu of expensive direct measurements?

Free testosterone (FT) measurement by equilibrium dialysis and liquid chromatography-tandem mass spectroscopy (LCMS/MS) is the "gold standard." We hypothesized that calculated FT values could substitute for measured values; compared FT results reported by Walter Reed Army Medical Center (WRAMC), Washington, DC, with results reported by the Seattle Veterans Affairs Health Care System, Seattle, WA, for 3 patient groups; and evaluated the calculated FT values by gold-standard measurements. Groups 1 and 2 included samples from 54 patients evaluated in Seattle and 94 evaluated at a primary care clinic in Alaska whose samples were analyzed in Seattle, respectively, whose care resulted in ordering an FT measurement.

A Prospective Study of Overuse Knee Injuries Among Female Athletes With Muscle Imbalances and Structural Abnormalities.

OBJECTIVE: To prospectively examine the influence of hamstring-to-quadriceps (H:Q) ratio and structural abnormalities on the prevalence of overuse knee injuries among female collegiate athletes. DESIGN AND SETTING: We used chi-square 2 x 2 contingency tables and the Fischer exact test to examine associations among H:Q ratios, structural abnormalities, and overuse knee injuries. SUBJECTS: Fifty-three apparently healthy women (age = 19.

Inhibitor-enhanced electron transfer: copper cytochrome c as a redox-inert probe of ternary complexes.

Copper-substituted cytochrome c (CuCc) has been used as a structurally faithful, redoxinert inhibitor to probe the mechanism of electron transfer (ET) between Cc molecules and cytochrome c peroxidase (CcP). This inhibitor enhances photoinduced ET quenching of the triplet excited state of a zinc-substituted protein (ZnCcP or ZnCc) by its iron(III) partner (Fe3+Cc or Fe3+CcP). These results show that CcP and Cc form a ternary complex in which one Cc molecule binds tightly at a surface domain of CcP having low ET reactivity, whereas the second Cc molecule binds weakly to the 1:1 complex at a second domain with markedly greater (approximately 10(3)) reactivity.

[Actinomycin DO inhibition of RNA biosynthesis and its interaction with DNA preparations].

Actinomycin D0 differing from actinomycin D in replacement of I residue of sarcosine by glycine in one of the peptide chains was found to have a lower inhibitory effect on RNA synthesis in various biological systems. On interaction of E. coli with DNA actinomycin D0 formed a complex with DNA having the binding constant K=1.