862 research outputs found
Whose Ground Truth Is It? Harvesting Lessons from Missouri’s 2018 Bumper Crop of Drought Observations
Drought-related decision-making and policy should go beyond numeric hydrometeorological data to incorporate information on how drought affects people, livelihoods, and ecosystems. The effects of drought are nested within environmental and human systems, and relevant data may not exist in readily accessible form. For example, drought may reduce forage growth, compounded by both late-season freezes and management decisions. An effort to gather crowdsourced drought observations in Missouri in 2018 yielded a much higher number of observations than did previous related efforts. Here we examine 1) the interests, circumstances, history, and recruitment messaging that coincided to produce a high number of reports in a short time; 2) whether and how information from volunteer observers was useful to state decision-makers and to U.S. Drought Monitor (USDM) authors; and 3) potential for complementary use of stakeholder and citizen science reports in assessing trustworthiness of volunteer-provided information. State officials and the Cattlemen’s Association made requests for reports, clearly linked to improving the accuracy of the USDM and the related financial benefit. Well-timed requests provided a focus for people’s energy and a reason to invest their time. State officials made use of the dense spatial coverage that observers provided. USDM authors were very cautious about a surge of reports coinciding closely with financial incentives linked to the Livestock Forage Disaster program. An after-the-fact comparison between stakeholder reports and parallel citizen science reports suggests that the two could be complementary, with potential for developing protocols to facilitate real-time use
A new approach to physical activity maintenance: Rationale, design, and baseline data from the Keep Active Minnesota trial
<p>Abstract</p> <p>Background</p> <p>Since many individuals who initiate physical activity programs are highly likely to return to a sedentary lifestyle, innovative strategies to efforts to increase the number of physically active older adults who successfully <it>maintain </it>beneficial levels of PA for a substantial length of time are needed.</p> <p>Methods/Design</p> <p>The Keep Active Minnesota Trial is a randomized controlled trial of an interactive phone- and mail-based intervention to help 50–70 year old adults who have recently increased their physical activity level, maintain that activity level over a 24-month period in comparison to usual care. Baseline, 6, 12, and 24 month measurement occurred via phone surveys with kilocalories expended per week in total and moderate-to-vigorous physical activity (CHAMPS Questionnaire) as the primary outcome measures. Secondary outcomes include hypothesized mediators of physical activity change (e.g., physical activity enjoyment, self-efficacy, physical activity self-concept), body mass index, and depression. Seven day accelerometry data were collected on a sub-sample of participants at baseline and 24-month follow-up.</p> <p>Discussion</p> <p>The Keep Active Minnesota study offers an innovative approach to the perennial problem of physical activity relapse; by focusing explicitly on physical activity maintenance, the intervention holds considerable promise for modifying the typical relapse curve. Moreover, if shown to be efficacious, the use of phone- and mail-based intervention delivery offers potential for widespread dissemination.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier: NCT00283452.</p
First cryo-scanning electron microscopy images and X-ray microanalyses of mucoromycotinian fine root endophytes in vascular plants
Aims. Arbuscule-producing fine root endophytes (FRE) (previously incorrectly Glomus tenue) were recently placed within subphylum Mucoromycotina; the first report of arbuscules outside subphylum Glomeromycotina. Here, we aimed to estimate nutrient concentrations in plant and fungal structures of FRE and to test the utility of cryo-scanning electron microscopy (cryoSEM) for studying these fungi.
Methods. To do so, we used replicated cryoSEM and X-ray microanalysis of heavily colonized roots of Trifolium subterraneum.
Results. Intercellular hyphae and hyphae in developed arbuscules were consistently very thin; 1.35 ± 0.03 µm and 0.99 ± 0.03 µm in diameter, respectively (mean ± SE). Several intercellular hyphae were often adjacent to each other forming ‘hyphal ropes’. Developed arbuscules showed higher phosphorus concentrations than senesced arbuscules and non-colonized structures. Senesced arbuscules showed greatly elevated concentrations of calcium and magnesium.
Conclusions. While uniformly thin hyphae and hyphal ropes are distinct features of FRE, the morphology of fully developed arbuscules, elevated phosphorus in fungal structures, and accumulation of calcium with loss of structural integrity in senesced arbuscules are similar to glomeromycotinian fungi. Thus, we provide evidence that FRE may respond to similar host-plant signals or that the host plant may employ a similar mechanism of association with FRE and AMF
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Global ecological predictors of the soil priming effect.
Identifying the global drivers of soil priming is essential to understanding C cycling in terrestrial ecosystems. We conducted a survey of soils across 86 globally-distributed locations, spanning a wide range of climates, biotic communities, and soil conditions, and evaluated the apparent soil priming effect using 13C-glucose labeling. Here we show that the magnitude of the positive apparent priming effect (increase in CO2 release through accelerated microbial biomass turnover) was negatively associated with SOC content and microbial respiration rates. Our statistical modeling suggests that apparent priming effects tend to be negative in more mesic sites associated with higher SOC contents. In contrast, a single-input of labile C causes positive apparent priming effects in more arid locations with low SOC contents. Our results provide solid evidence that SOC content plays a critical role in regulating apparent priming effects, with important implications for the improvement of C cycling models under global change scenarios
Erythropoietin Treatment in Traumatic Brain Injury: Operation Brain Trauma Therapy
Experimental studies targeting traumatic brain injury (TBI) have reported that erythropoietin (EPO) is an endogenous neuroprotectant in multiple models. In addition to its neuroprotective effects, it has also been shown to enhance reparative processes including angiogenesis and neurogenesis. Based on compelling pre-clinical data, EPO was tested by the Operation Brain Trauma Therapy (OBTT) consortium to evaluate therapeutic potential in multiple TBI models along with biomarker assessments. Based on the pre-clinical TBI literature, two doses of EPO (5000 and 10,000 IU/kg) were tested given at 15 min after moderate fluid percussion brain injury (FPI), controlled cortical impact (CCI), or penetrating ballistic-like brain injury (PBBI) with subsequent behavioral, histopathological, and biomarker outcome assessments. There was a significant benefit on beam walk with the 5000 IU dose in CCI, but no benefit on any other motor task across models in OBTT. Also, no benefit of EPO treatment across the three TBI models was noted using the Morris water maze to assess cognitive deficits. Lesion volume analysis showed no treatment effects after either FPI or CCI; however, with the 5000 IU/kg dose of EPO, a paradoxical increase in lesion volume and percent hemispheric tissue loss was seen after PBBI. Biomarker assessments included measurements of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase-L1 (UCH-L1) in blood at 4 or 24 h after injury. No treatment effects were seen on biomarker levels after FPI, whereas treatment at either dose exacerbated the increase in GFAP at 24 h in PBBI but attenuated 24-4 h delta UCH-L1 levels at high dose in CCI. Our data indicate a surprising lack of efficacy of EPO across three established TBI models in terms of behavioral, histopathological, and biomarker assessments. Although we cannot rule out the possibility that other doses or more prolonged treatment could show different effects, the lack of efficacy of EPO reduced enthusiasm for its further investigation in OBTT
Trait convergence in photosynthetic nutrient-use efficiency along a 2-million year dune chronosequence in a global biodiversity hotspot
The Jurien Bay dune chronosequence in south-western Australia's biodiversity hotspot comprises sites differing in nutrient availability, with phosphorus (P) availability declining strongly with increasing soil age. We have explored the exceptionally high photosynthetic Pause efficiency (PPUE) of Proteaceae in this region, triggering the question what the PPUE of co-occurring species in other families might be along the Jurien Bay chronosequence.
We explored how traits associated with PPUE, photosynthetic nitrogen (N)-use efficiency (PNUE) and leaf respiration might converge along the chronosequence, and whether Proteaceae and non-Proteaceae species differ in leaf traits associated with nutrient use.
Seven to 10 species were sampled at three sites differing in nutrient availability (ranging from N- to P- limited). Measurements of leaf light-saturated photosynthesis and dark respiration were integrated with measurements of total N and P concentration in both mature and senesced leaves, and leaf mass per unit area (LMA).
Contrary to what is known for other chronosequences, rates of photosynthesis and respiration did not decrease with increasing soil age and LMA along the Jurien Bay chronosequence. However, they increased when expressed per unit leaf P. Both N and P were used much more efficiently for photosynthesis on nutrient-poor sites, in both Proteaceae and non-Proteaceae species. Proteaceae had the fastest rate of photosynthesis per unit leaf P, followed by species that preferentially allocate P to mesophyll cells, rather than epidermal cells.
Synthesis. Our results show that with declining soil P availability, photosynthetic P-use efficiency of all investigated species from different families increased. Plants growing on the oldest, most nutrient-impoverished soils exhibited similar rates of CO2 exchange as plants growing on more nutrient-rich younger soils, and extraordinarily high photosynthetic P-use efficiency. This indicates convergence in leaf traits related to photosynthetic nutrient use on severely P-impoverished sites.Australian Research Council, Grant/Award
Number: CE140100008, DP130100005,
DP0985685, DP110101120 and
DP0986823; University of Western
Australi
Faint High Latitude Carbon Stars Discovered by the Sloan Digital Sky Survey: Methods and Initial Results
We report the discovery of 39 Faint High Latitude Carbon Stars (FHLCs) from
Sloan Digital Sky Survey commissioning data. The objects, each selected
photometrically and verified spectroscopically, range over 16.6 < r* < 20.0,
and show a diversity of temperatures as judged by both colors and NaD line
strengths. At the completion of the Sloan Survey, there will be many hundred
homogeneously selected and observed FHLCs in this sample. We present proper
motion measures for each object, indicating that the sample is a mixture of
extremely distant (>100 kpc) halo giant stars, useful for constraining halo
dynamics, plus members of the recently-recognized exotic class of very nearby
dwarf carbon (dC) stars. Motions, and thus dC classification, are inferred for
40-50 percent of the sample, depending on the level of statistical significance
invoked. The new list of dC stars presented here, although selected from only a
small fraction of the final SDSS, doubles the number of such objects found by
all previous methods. (Abstract abridged).Comment: Accepted for publication in The Astronomical Journal, Vol. 124, Sep.
2002, 40 pages, 7 figures, AASTeX v5.
The Lantern Vol. 46, No. 2, April 1980
• The Voyage to Man\u27s Destiny • If I Could Keep the Times • Barstool Blues • I Didn\u27t Know • Felonious, Friend • Cool Ride • Georgia • Let Us Eat and Drink • In a Field • New Born Foal • Union to Freedom • In the Woods • Anthropomorphism • Runner • C.C. • Lake Attempt • A Fuzzy Blue Line • Trust Me • Haven\u27t We Met Before? • Rationality • Expecting Me • Short Storyhttps://digitalcommons.ursinus.edu/lantern/1116/thumbnail.jp
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Direct links between the vernalization response and other key traits of cereal crops
Transcription of the VERNALIZATION1 gene (VRN1) is induced by prolonged cold
(vernalization) to trigger flowering of cereal crops, such as wheat and barley. VRN1 encodes a
MADS box transcription factor that promotes flowering by regulating the expression of other
genes. Here we use transcriptome sequencing (RNA-seq) and chromatin immunoprecipitation
sequencing (ChIP-seq) to identify direct targets of VRN1. Over 500 genomic regions
were identified as potential VRN1-binding targets by ChIP-seq. VRN1 binds the promoter of
FLOWERING LOCUS T-like 1, a promoter of flowering in vernalized plants. VRN1 also targets
VERNALIZATION2 and ODDSOC2, repressors of flowering that are downregulated in
vernalized plants. RNA-seq identified additional VRN1 targets that might play roles
in triggering flowering. Other targets of VRN1 include genes that play central roles in
low-temperature-induced freezing tolerance, spike architecture and hormone metabolism.
This provides evidence for direct regulatory links between the vernalization response pathway
and other important traits in cereal crops
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