422 research outputs found
Estimation of urban sensible heat flux using a dense wireless network of observations
The determination of the sensible heat flux over urban terrain is challenging due to irregular surface geometry and surface types. To address this, in 2006-07, a major field campaign (LUCE) took place at the Ăcole Polytechnique FĂ©dĂ©rale de Lausanne campus, a moderately occupied urban site. A distributed network of 92 wireless weather stations was combined with routine atmospheric profiling, offering high temporal and spatial resolution meteorological measurements. The objective of this study is to estimate the sensible heat flux over the built environment under convective conditions. Calculations were based on Monin-Obukhov similarity for temperature in the surface layer. The results illustrate a good agreement between the sensible heat flux inferred from the thermal roughness length approach and independent calibrated measurements from a scintillometer located inside the urban canopy. It also shows that using only one well-selected station can provide a good estimate of the sensible heat flux over the campus for convective conditions. Overall, this study illustrates how an extensive network of meteorological measurements can be a useful tool to estimate the sensible heat flux in complex urban environment
Maine Blueberry Advisory Committee Research Report
The 1990 edition of the Maine Blueberry Advisory Committee Research Reports was prepared for the Maine Wild Blueberry Commission and the University of Maine Wild Blueberry Advisory Committee by researchers with the Maine Agricultural Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include:
1. Biology and action thresholds of secondary blueberry pests
2. Control of blueberry maggot
3. Control of secondary blueberry pests
4. Application of steam as a method of controlling secondary pest insects on lowbush blueberry: a feasibility study
5. Pollination of the lowbush blueberry by native bees
6. Nitrogen-phosphorus study
7. Potassium study
8. Multiple cropping of wild stands
9. Phosphorus dose/response curve
10. Improvement in the color and texture of the canned blueberry
11. The effect of fertilization and irrigation on blueberry fruit quality
12. Investigation of preprocess changes (chemical, microbiological, and/or physical) that could lead to the development of a simple and inexpensive method to measure preprocess berry spoilage
13. The effect of postharvest handling on the dietary fiber and ellagic acid content of lowbush blueberries
14. Determination of pesticide residue levels in freshly harvested and processed lowbush blueberries
15. Evaluation of Defoliating Diseases
16. Vacuum Sanitation for Disease Control
17. Evaluation and modification of commercial herbicide applications
18. Evaluation of the suitability of remote sensing to evaluate plant cover in lowbush blueberry fields
19. Evaluation of Sethoxydin (POAST) in lowbush blueberry fields
20. Seedling pruning study
21. Evaluation of norflurazon (SOLICAM) with or without hexazinone (VELPAR) for bunchberry control
22. Selective wiper and mechanical control of dogbane and bracken fern
23. Evaluation of norflurazon (SOLICAM) in fall vs spring for oatgrass control
24. Evaluation of sulfonyl urea herbicides for bunchberry control
25. Evaluation of postemergence applications of DPX-L5300 for bunchberry control
26. Effect of time of application and formulation of hexazinone (VELPAR) on blueberry and bunchberry
27. Investigations of lowbush blueberry fruit-bud cold hardiness
28. The economics of investing in irrigation for lowbush blueberries
29. Effects of irrigation on lowbush blueberry yield and quality
30. Groundwater and surface water development for blueberry irrigation
31. Design, fabrication and testing of an experimental sterilizer for blueberry field
Estimation of urban sensible heat flux using a dense wireless network of observations
The determination of the sensible heat flux over urban terrain is challenging due to irregular surface geometry and surface types. To address this, in 2006â07, a major field campaign (LUCE) took place at the Ăcole Polytechnique FĂ©dĂ©rale de Lausanne campus, a moderately occupied urban site. A distributed network of 92 wireless weather stations was combined with routine atmospheric profiling, offering high temporal and spatial resolution meteorological measurements. The objective of this study is to estimate the sensible heat flux over the built environment under convective conditions. Calculations were based on MoninâObukhov similarity for temperature in the surface layer. The results illustrate a good agreement between the sensible heat flux inferred from the thermal roughness length approach and independent calibrated measurements from a scintillometer located inside the urban canopy. It also shows that using only one well-selected station can provide a good estimate of the sensible heat flux over the campus for convective conditions. Overall, this study illustrates how an extensive network of meteorological measurements can be a useful tool to estimate the sensible heat flux in complex urban environments
Endothelial NADPH oxidase-2 promotes interstitial cardiac fibrosis and diastolic dysfunction through proinflammatory effects and endothelial-mesenchymal transition
OBJECTIVES: This study sought to investigate the effect of endothelial dysfunction on the development of cardiac hypertrophy and fibrosis. BACKGROUND: Endothelial dysfunction accompanies cardiac hypertrophy and fibrosis, but its contribution to these conditions is unclear. Increased nicotinamide adenine dinucleotide phosphate oxidase-2 (NOX2) activation causes endothelial dysfunction. METHODS: Transgenic mice with endothelial-specific NOX2 overexpression (TG mice) and wild-type littermates received long-term angiotensin II (AngII) infusion (1.1 mg/kg/day, 2 weeks) to induce hypertrophy and fibrosis. RESULTS: TG mice had systolic hypertension and hypertrophy similar to those seen in wild-type mice but developed greater cardiac fibrosis and evidence of isolated left ventricular diastolic dysfunction (p < 0.05). TG myocardium had more inflammatory cells and VCAM-1-positive vessels than did wild-type myocardium after AngII treatment (both p < 0.05). TG microvascular endothelial cells (ECs) treated with AngII recruited 2-fold more leukocytes than did wild-type ECs in an in vitro adhesion assay (p < 0.05). However, inflammatory cell NOX2 per se was not essential for the profibrotic effects of AngII. TG showed a higher level of endothelial-mesenchymal transition (EMT) than did wild-type mice after AngII infusion. In cultured ECs treated with AngII, NOX2 enhanced EMT as assessed by the relative expression of fibroblast versus endothelial-specific markers. CONCLUSIONS: AngII-induced endothelial NOX2 activation has profound profibrotic effects in the heart in vivo that lead to a diastolic dysfunction phenotype. Endothelial NOX2 enhances EMT and has proinflammatory effects. This may be an important mechanism underlying cardiac fibrosis and diastolic dysfunction during increased renin-angiotensin activation
1992 Blueberry Research Progress Reports
The 1992 Blueberry Research Progress Reports pertain to and report on research conducted in 1991, and were prepared for the Maine Wild Blueberry Commission and the University of Maine Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1992 CSRS Progress Reports:
1. Investigation of Groundwater Resources
2. Sprinkler Irrigation
3. Investigation of Preprocess Changes Leading to Berry Spoilage
4. Effect of Fertilization and Irrigation on Blueberry Quality
5. Effects of Calcium Salts and Citric Acid on Quality of Canned Lowbush Blueberries
6. Pollination of Lowbush Blueberry by Native Bees
7. Application of Heat for Controlling Insects
8. Investigations of Lowbush Blueberry Fruit Bud Cold-Hardiness
9. Steam Sterilization in Lowbush Blueberry Fields
10. Heat-Tolerant Molds
11. Vacuum Sanitation for Disease Control
12. Evaluation of Infrared Burner for Weed Control
13. Evaluation and Modification of Commercial Herbicide Wipers
14. Evaluation of Remote Sensing to Estimate Plant Cover in Lowbush Blueberry Fields
15. Comparison of Three Mechanical Blueberry Harvesters vs. Hand Raking
Advisory Committee Research Reports:
16. Biology and action thresholds of secondary blueberry insects
17. Control of secondary blueberry pests
18. Control of blueberry maggot
19. Effects of calcium salts and citric acid on the quality of canned lowbush blueberries
20. The effects of postharvest handling on the dietary fiber and ellagic acid content of lowbush blueberries
21. Investigation of preprocessing changes that could lead to development of simple and inexpensive method to measure preprocessing berry spoilage
22. Determination of pesticide residue levels in fresh and processed lowbush blueberries
23. Vacuum sanitation for disease control
24. Heat-tolerant molds
25. Seedling pruning study
26. Effect of time and rate of application of Clopyralid for control of Vetch in lowbush blueberries
27. Evaluation and modification of commercial herbicide wipers
28. Effect of time of application and formulation of Hexazinone (Velpar) on Blueberry and Bunchberry
29. Evaluation of postemergence applications of Tribenuron Methyl for Bunchberry control
30. Thresholds of Dogbane and Bracken Fern by mechanical and chemical control in lowbush blueberry fields
31. Evaluation of the suitability of remote sensing to evaluate plant cover in lowbush blueberry fields
32. Evalution of infrared burner for weed control
33. Effect of time of fall pruning on growth and productivity of blueberry and evaluation of infrared burner to prune blueberries
34. Effect of Boron on lowbush blueberry fruit set and yield
35. Winter injury protection by potassium
36. Multiple cropping of wild stands
37. Nitrogen-Phosphorus study
38. Phosphorus dose/response curve
39. Investigations of lowbush blueberry fruit bud cold-hardines
Scalar flux profile relationships over the open ocean
Author Posting. © American Geophysical Union, 2004. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 109 (2004): C08S09, doi:10.1029/2003JC001960.The most commonly used flux-profile relationships are based on Monin-Obukhov (MO) similarity theory. These flux-profile relationships are required in indirect methods such as the bulk aerodynamic, profile, and inertial dissipation methods to estimate the fluxes over the ocean. These relationships are almost exclusively derived from previous field experiments conducted over land. However, the use of overland measurements to infer surface fluxes over the ocean remains questionable, particularly close to the ocean surface where wave-induced forcing can affect the flow. This study investigates the flux profile relationships over the open ocean using measurements made during the 2000 Fluxes, Air-Sea Interaction, and Remote Sensing (FAIRS) and 2001 GasEx experiments. These experiments provide direct measurement of the atmospheric fluxes along with profiles of water vapor and temperature. The specific humidity data are used to determine parameterizations of the dimensionless gradients using functional forms of two commonly used relationships. The best fit to the Businger-Dyer relationship [ Businger, 1988 ] is found using an empirical constant of a q = 13.4 ± 1.7. The best fit to a formulation that has the correct form in the limit of local free convection [e.g., Wyngaard, 1973 ] is found using a q = 29.8 ± 4.6. These values are in good agreement with the consensus values from previous overland experiments and the Coupled Ocean-Atmosphere Response Experiment (COARE) 3.0 bulk algorithm [ Fairall et al., 2003 ]; e.g., the COARE algorithm uses empirical constants of 15 and 34.2 for the Businger-Dyer and convective forms, respectively. Although the flux measurements were made at a single elevation and local similarity scaling is applied, the good agreement implies that MO similarity is valid within the marine atmospheric surface layer above the wave boundary layer.The FAIRS work was supported by the
Office of Naval Research grant N00014-00-1-0403 while the GasEx work
was supported by the National Science Foundation grant OCE-9986724
Neurovascular Coupling Remains Intact During Incremental Ascent to High Altitude (4240 m) in Acclimatized Healthy Volunteers
Neurovascular coupling (NVC) is the temporal link between neuronal metabolic activity and regional cerebral blood flow (CBF), supporting adequate delivery of nutrients. Exposure to high altitude (HA) imposes several stressors, including hypoxia and hypocapnia, which modulate cerebrovascular tone in an antagonistic fashion. Whether these contrasting stressors and subsequent adaptations affect NVC during incremental ascent to HA is unclear. The aim of this study was to assess whether incremental ascent to HA influences the NVC response. Given that CBF is sensitive to changes in arterial blood gasses, in particular PaCO2, we hypothesized that the vasoconstrictive effect of hypocapnia during ascent would decrease the NVC response. 10 healthy study participants (21.7 ± 1.3 years, 23.57 ± 2.00 kg/m2, mean ± SD) were recruited as part of a research expedition to HA in the Nepal Himalaya. Resting posterior cerebral artery velocity (PCAv), arterial blood gasses (PaO2, SaO2, PaCO2, [HCO3-], base excess and arterial blood pH) and NVC response of the PCA were measured at four pre-determined locations: Calgary/Kathmandu (1045/1400 m, control), Namche (3440 m), Deboche (3820 m) and Pheriche (4240 m). PCAv was measured using transcranial Doppler ultrasound. Arterial blood draws were taken from the radial artery and analyzed using a portable blood gas/electrolyte analyzer. NVC was determined in response to visual stimulation (VS; Strobe light; 6 Hz; 30 s on/off Ă 3 trials). The NVC response was averaged across three VS trials at each location. PaO2, SaO2, and PaCO2 were each significantly decreased at 3440, 3820, and 4240 m. No significant differences were found for pH at HA (P > 0.05) due to significant reductions in [HCO3-] (P < 0.043). As expected, incremental ascent to HA induced a state of hypoxic hypocapnia, whereas normal arterial pH was maintained due to renal compensation. NVC was quantified as the delta (Î) PCAv from baseline for mean PCAv, peak PCAv and total area under the curve (ÎPCAv tAUC) during VS. No significant differences were found for Îmean, Îpeak or ÎPCAv tAUC between locations (P > 0.05). NVC remains remarkably intact during incremental ascent to HA in healthy acclimatized individuals. Despite the array of superimposed stressors associated with ascent to HA, CBF and NVC regulation may be preserved coincident with arterial pH maintenance during acclimatization
Clinical evaluation of iron treatment efficiency among non-anemic but iron-deficient female blood donors: a randomized controlled trial
ABSTRACT: Iron deficiency without anemia (IDWA) is related to adverse symptoms that can be relieved by supplementation. Since a blood donation can induce such an iron deficiency, we investigated the clinical impact of an iron treatment after blood donation. METHODS: One week after donation, we randomly assigned 154 female donors with IDWA aged <50 years to a 4-week oral treatment of ferrous sulfate vs. placebo. The main outcome was the change in the level of fatigue before and after the intervention. Also evaluated were aerobic capacity, mood disorder, quality of life, compliance and adverse events. Biological markers were hemoglobin and ferritin. RESULTS: Treatment effect from baseline to 4 weeks for hemoglobin and ferritin were 5.2 g/L (p < 0.01) and 14.8 ng/mL (p < 0.01) respectively. No significant clinical effect was observed for fatigue (-0.15 points, 95% confidence interval -0.9 to 0.6, p = 0.697) or for other outcomes. Compliance and interruption for side effects was similar in both groups. Additionally, blood donation did not induce overt symptoms of fatigue in spite of the significant biological changes it produces. CONCLUSIONS: These data are valuable as they enable us to conclude that donors with IDWA after a blood donation would not clinically benefit from iron supplementation. Trial registration: NCT00689793
Cardiorespiratory hysteresis during incremental high altitude ascent-descent quantifies the magnitude of ventilatory acclimatization
Maintenance of arterial blood gases is achieved through sophisticated regulation of ventilation, mediated by central and peripheral chemoreflexes. Respiratory chemoreflexes are important during exposure to high altitude due to the competing influence of hypoxia and hypoxic hyperventilationâmediated hypocapnia on steadyâstate ventilatory drive. Interâindividual variability exists in ventilatory acclimatization to high altitude, potentially affecting the development of acute mountain sickness (AMS). We aimed to quantify ventilatory acclimatization to high altitude by comparing differential ascent and descent values (i.e. hysteresis) in steadyâstate cardiorespiratory variables. We hypothesized that (a) the hysteresis area formed by cardiorespiratory variables during ascent and descent would quantify the magnitude of ventilatory acclimatization, and (b) larger hysteresis areas would be associated with lower AMS symptom scores during ascent. In 25 healthy, Diamoxâfree trekkers ascending to and descending from 5160 m, cardiorespiratory hysteresis was measured in the pressure of endâtidal (PET)CO2, peripheral oxygen saturation (SpO2), minute ventilation (VÌE), chemoreceptor stimulus index (SI; PETCO2/SpO2) and the calculated steadyâstate chemoreflex drive (SSâCD; VÌE/SI) using portable devices (capnograph, peripheral pulse oximeter and respirometer, respectively). AMS symptoms were assessed daily using the Lake Louise Questionnaire. We found that (a) ascentâdescent hysteresis was present in all cardiorespiratory variables, (b) SSâCD is a valid metric for tracking ventilatory acclimatization to high altitude and (c) highest AMS scores during ascent were significantly, moderately and inverselyâcorrelated to SSâCD hysteresis magnitude (rs = â0.408, P = 0.043). We propose that ascentâdescent hysteresis is a novel and feasible way to quantify ventilatory acclimatization in trekkers during high altitude exposure
Surface Energy Budgets of Arctic Tundra During Growing Season
This study analyzed summer observations of diurnal and seasonal surface energy budgets across several monitoring sites within the Arctic tundra underlain by permafrost. In these areas, latent and sensible heat fluxes have comparable magnitudes, and ground heat flux enters the subsurface during short summer intervals of the growing period, leading to seasonal thaw. The maximum entropy production (MEP) model was tested as an input and parameter parsimonious model of surface heat fluxes for the simulation of energy budgets of these permafrostâunderlain environments. Using net radiation, surface temperature, and a single parameter characterizing the thermal inertia of the heat exchanging surface, the MEP model estimates latent, sensible, and ground heat fluxes that agree closely with observations at five sites for which detailed flux data are available. The MEP potential evapotranspiration model reproduces estimates of the PenmanâMonteith potential evapotranspiration model that requires at least five input meteorological variables (net radiation, ground heat flux, air temperature, air humidity, and wind speed) and empirical parameters of surface resistance. The potential and challenges of MEP model application in sparsely monitored areas of the Arctic are discussed, highlighting the need for accurate measurements and constraints of ground heat flux.Plain Language SummaryGrowing season latent and sensible heat fluxes are nearly equal over the Arctic permafrost tundra regions. Persistent ground heat flux into the subsurface layer leads to seasonal thaw of the top permafrost layer. The maximum energy production model accurately estimates the latent, sensible, and ground heat flux of the surface energy budget of the Arctic permafrost regions.Key PointThe MEP model is parsimonious and well suited to modeling surface energy budget in dataâsparse permafrost environmentsPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150560/1/jgrd55584.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150560/2/jgrd55584_am.pd
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