scholarly journals Observations of atmosphere-biosphere exchange of total and speciated peroxynitrates: nitrogen fluxes and biogenic sources of peroxynitrates

2012 ◽  
Vol 12 (20) ◽  
pp. 9763-9773 ◽  
Author(s):  
K.-E. Min ◽  
S. E. Pusede ◽  
E. C. Browne ◽  
B. W. LaFranchi ◽  
P. J. Wooldridge ◽  
...  
Keyword(s):  
Ponderosa Pine ◽  
Global Scale ◽  
Time Of Day ◽  
Concentration Gradients ◽  
Nitrogen Fluxes ◽  
Plant Canopies ◽  
Biogenic Voc ◽  
The Impact ◽  
Ponderosa Pine Forest ◽  
Recent Laboratory

Abstract. Peroxynitrates are responsible for global scale transport of reactive nitrogen. Recent laboratory observations suggest that they may also play an important role in delivery of nutrients to plant canopies. We measured eddy covariance fluxes of total peroxynitrates (ΣPNs) and three individual peroxynitrates (APNs ≡ PAN + PPN + MPAN) over a ponderosa pine forest during the Biosphere Effects on AeRosols and Photochemistry EXperiment 2009 (BEARPEX 2009). Concentrations of these species were also measured at multiple heights above and within the canopy. While the above-canopy daytime concentrations are nearly identical for ΣPNs and APNs, we observed the downward flux of ΣPNs to be 30–60% slower than the flux of APNs. The vertical concentration gradients of ΣPNs and APNs vary with time of day and exhibit different temperature dependencies. These differences can be explained by the production of peroxynitrates other than PAN, PPN, and MPAN within the canopy (presumably as a consequence of biogenic VOC emissions) and upward fluxes of these PN species. The impact of this implied peroxynitrate flux on the interpretation of NOx fluxes and ecosystem N exchange is discussed.

scholarly journals Observations of atmosphere-biosphere exchange of total and speciated peroxynitrates: nitrogen fluxes and biogenic sources of peroxynitrates

2012 ◽  
Vol 12 (2) ◽  
pp. 6205-6233 ◽  
Author(s):  
K.-E. Min ◽  
S. E. Pusede ◽  
E. C. Browne ◽  
B. W. LaFranchi ◽  
P. J. Wooldridge ◽  
...  
Keyword(s):  
Ponderosa Pine ◽  
Global Scale ◽  
Time Of Day ◽  
Concentration Gradients ◽  
Nitrogen Fluxes ◽  
Plant Canopies ◽  
Biogenic Voc ◽  
The Impact ◽  
Ponderosa Pine Forest ◽  
Recent Laboratory

Abstract. Peroxynitrates are responsible for global scale transport of reactive nitrogen. Recent laboratory observations suggest that they may also play an important role in delivery of nutrients to plant canopies. We measured eddy covariance fluxes of total peroxynitrates (ΣPNs) and three individual peroxynitrates (APNs ≡ PAN + PPN + MPAN) over a ponderosa pine forest during the Biosphere Effects on AeRosols and Photochemistry EXperiment 2009 (BEARPEX 2009). Concentrations of these species were also measured at multiple heights above and within the canopy. While the above-canopy daytime concentrations are nearly identical for ΣPNs and APNs, we observed the downward flux of ΣPNs to be 30–60% slower than the flux of APNs. The vertical concentration gradients of ΣPNs and APNs vary with time of day and exhibit different temperature dependencies. These differences can be explained by the production of peroxynitrates other than PAN, PPN, and MPAN within the canopy (presumably as a consequence of biogenic VOC emissions) and upward fluxes of these PN species. The impact of this implied peroxynitrate flux on the interpretation of NOx fluxes and ecosystem N exchange is discussed.

scholarly journals Ethene, propene, butene and isoprene emissions from a ponderosa pine forest measured by Relaxed Eddy Accumulation

2017 ◽  
Author(s):  
Robert C. Rhew ◽  
Malte Julian Deventer ◽  
Andrew A. Turnipseed ◽  
Carsten Warneke ◽  
John Ortega ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Ponderosa Pine ◽  
Pine Forest ◽  
Anthropogenic Sources ◽  
Light Alkenes ◽  
Diurnal Cycles ◽  
Relaxed Eddy Accumulation ◽  
Biogenic Voc ◽  
Global Emissions ◽  
Ponderosa Pine Forest

Abstract. Alkenes are reactive hydrocarbons that influence local and regional atmospheric chemistry, playing important roles in the photochemical production of tropospheric ozone and in the formation of secondary organic aerosols. The simplest alkene, ethene (ethylene), is a major plant hormone and ripening agent for agricultural commodities. The group of light alkenes (C2-C4) originates from both biogenic and anthropogenic sources, but their biogenic sources are poorly characterized, with limited field-based flux observations. Here we report net ecosystem fluxes of light alkenes and isoprene from a semi-arid ponderosa pine forest in the Rocky Mountains of Colorado, USA using the relaxed eddy accumulation (REA) technique during the summer of 2014. Ethene, propene and butene emissions have significant diurnal cycles, with maximum emissions at midday. The fluxes were correlated with each other and followed general ecosystem trends of CO2, water vapor, light and temperature. The light alkenes contribute significantly to the overall biogenic source of reactive hydrocarbons, roughly 15 % of the dominant biogenic VOC, 2-methyl-3-buten-2-ol. The measured ecosystem scale fluxes are nearly twice as large as estimates used in global emissions models for this type of ecosystem.

Lick Creek historic photographic series: a century of change in a ponderosa pine forest in western Montana, US

2018 ◽  
Author(s):  
Sharon M. Hood ◽  
Duncan C. Lutes ◽  
Justin S. Crotteau ◽  
Christopher R. Keyes ◽  
Anna Sala ◽  
...  
Keyword(s):  
Ponderosa Pine ◽  
Pine Forest ◽  
Western Montana ◽  
Ponderosa Pine Forest

scholarly journals Patient preferences for use of virtual consultations in an orthopaedic rehabilitation setting: Results from a discrete choice experiment

2021 ◽  
pp. 135581962110354
Author(s):  
Anthony W Gilbert ◽  
Emmanouil Mentzakis ◽  
Carl R May ◽  
Maria Stokes ◽  
Jeremy Jones
Keyword(s):  
Conceptual Model ◽  
Discrete Choice Experiment ◽  
Discrete Choice ◽  
Patient Preferences ◽  
Choice Experiment ◽  
Best Practice ◽  
Time Of Day ◽  
Problem Area ◽  
Fractional Factorial ◽  
The Impact

Objective Virtual Consultations may reduce the need for face-to-face outpatient appointments, thereby potentially reducing the cost and time involved in delivering health care. This study reports a discrete choice experiment (DCE) that identifies factors that influence patient preferences for virtual consultations in an orthopaedic rehabilitation setting. Methods Previous research from the CONNECT (Care in Orthopaedics, burdeN of treatmeNt and the Effect of Communication Technology) Project and best practice guidance informed the development of our DCE. An efficient fractional factorial design with 16 choice scenarios was created that identified all main effects and partial two-way interactions. The design was divided into two blocks of eight scenarios each, to reduce the impact of cognitive fatigue. Data analysis were conducted using binary logit regression models. Results Sixty-one paired response sets (122 subjects) were available for analysis. DCE factors (whether the therapist is known to the patient, duration of appointment, time of day) and demographic factors (patient qualifications, access to equipment, difficulty with activities, multiple health issues, travel costs) were significant predictors of preference. We estimate that a patient is less than 1% likely to prefer a virtual consultation if the patient has a degree, is without access to the equipment and software to undertake a virtual consultation, does not have difficulties with day-to-day activities, is undergoing rehabilitation for one problem area, has to pay less than £5 to travel, is having a consultation with a therapist not known to them, in 1 weeks’ time, lasting 60 minutes, at 2 pm. We have developed a simple conceptual model to explain how these factors interact to inform preference, including patients’ access to resources, context for the consultation and the requirements of the consultation. Conclusions This conceptual model provides the framework to focus attention towards factors that might influence patient preference for virtual consultations. Our model can inform the development of future technologies, trials, and qualitative work to further explore the mechanisms that influence preference.

scholarly journals 82 The impact of feeding treats containing cannabidiol (CBD) on the daily activity level of dogs

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 60-61
Author(s):  
Elizabeth M Morris ◽  
Susanna E Kitts-Morgan ◽  
Dawn M Spangler ◽  
Kyle R McLeod ◽  
David L Harmon
Keyword(s):  
Daily Activity ◽  
Block Design ◽  
Companion Animals ◽  
Total Activity ◽  
Time Of Day ◽  
Activity Level ◽  
Activity Levels ◽  
Quiet Time ◽  
Activity Duration ◽  
The Impact

Abstract Growing public interest in and use of Cannabidiol (CBD) in companion animals has amplified the need to elucidate potential impacts. The purpose of this investigation was to determine the impact of CBD on daily activity of adult dogs. Twenty-four dogs (18.0 ± 3.4 kg) were utilized in a randomized complete block design with treatments consisting of control, 2 mg CBD/kg BW/d, and 4 mg CBD/kg BW/d split between two treats administered after twice-daily exercise (7:00-9:00 and 17:00-19:00). Four hours each day (10:00-12:00, AM and 13:30-15:30, PM), were designated as time when no persons entered the kennels, with 2 h designated as Quiet Time and the other 2 h as Music Time, where calming music played over speakers. Quiet and Music sessions were randomly allotted to daily AM or PM times. Activity monitors were fitted to dogs’ collars for continuous collection of activity parameters. Data were collected over a 2-wk baseline period to block dogs by activity level (high or low) before randomly assigning dogs within each block to treatments. After 1 wk of treatment adaptation, activity parameters were collected for 2 wk. Data were tested for normality using the UNIVARIATE procedure in SAS before examining differences using the MIXED procedure in SAS, including effects of treatment, day, session (Quiet or Music), time of day (AM or PM), and accompanying interactions. CBD did not alter total activity points (P = 0.9971) or activity duration (P = 0.8776). CBD tended (P = 0.0692) to reduce scratching compared to control. Irrespective of treatment, dogs were more active in PM than AM (P < 0.0001). Regardless of session, dogs receiving 4 mg/kg/d tended (P = 0.0914) to be less active in the PM than control. CBD did not affect activity duration during exercise periods (P = 0.1425), but dogs receiving CBD ran more than control (P = 0.0339). These results indicate that when supplemented up to 4 mg/kg/d, CBD does not negatively impact daily activity levels of dogs.

scholarly journals Applying Google Trends’ Search Popularity Indicator to Professional Cycling

2021 ◽  
pp. 152700252098832
Author(s):  
Alexander Genoe ◽  
Ronald Rousseau ◽  
Sandra Rousseau
Keyword(s):  
Fixed Effects ◽  
Global Scale ◽  
Google Trends ◽  
Panel Model ◽  
Tour De France ◽  
Country Preference ◽  
The Impact ◽  
Professional Cycling

This study uses Google Trends data to analyze the impact of the main events in the Tour de France 2019 on cyclists’ online popularity in 12 countries and at a global scale. A fixed effects panel model revealed a strong own-country preference. While online popularity increased with the duration of the Tour, race incidents strongly influenced online popularity. Besides the yellow jersey, winning a stage was more important than wearing the green, white or polka dot jersey for most regions. Still, on a global scale, young cyclists’ online popularity benefited more from wearing the white jersey than from winning a Tour stage.

Lack of Vesicular-Arbuscular Mycorrhizal Inoculum in a Ponderosa Pine Forest

Ecology ◽  
1984 ◽  
Vol 65 (6) ◽  
pp. 1755-1759 ◽  
Author(s):  
D. A. Kovacic ◽  
T. V. St. John ◽  
M. I. Dyer
Keyword(s):  
Ponderosa Pine ◽  
Arbuscular Mycorrhizal ◽  
Pine Forest ◽  
Vesicular Arbuscular ◽  
Ponderosa Pine Forest
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