The hydrology of a drained, afforested peat bog in southern Scotland, 1977–1986

1987 ◽  
Vol 78 (4) ◽  
pp. 297-303 ◽  
Author(s):  
D. C. Ledger ◽  
S. E. Harper
Keyword(s):  
Substantial Reduction ◽  
Water Yield ◽  
Peat Bog ◽  
Drainage Network ◽  
Hydraulic Efficiency ◽  
Runoff Regime ◽  
Runoff Plots

ABSTRACTThis paper reports on the progress to date of a long-term investigation of the effects of drainage and afforestation on the hydrology of a peat bog near Edinburgh based on the use of runoff plots and other related equipment. The hydrology of the area immediately after ploughing is described and recently collected data are presented to show how this has changed over a six-year period. The main changes appear to be a substantial reduction in water yield and a move towards a less flashy runoff regime. Data are presented to show that these are most probably due to an increase in the amount of rainfall intercepted by the vegetation now covering the area and to a deterioration in the hydraulic efficiency of the drainage network.

scholarly journals WALANT–Epinephrine injection may lead to short term, reversible episodes of critical oxygen saturation in the fingertips

2021 ◽  
Vol 141 (3) ◽  
pp. 527-533
Author(s):  
P. Moog ◽  
M. Dozan ◽  
J. Betzl ◽  
I. Sukhova ◽  
H. Kükrek ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Substantial Reduction ◽  
Tissue Perfusion ◽  
Critical Levels ◽  
Short Term ◽  
Doppler Flowmetry ◽  
Epinephrine Injection ◽  
Venous Oxygen Saturation

Abstract Introduction Although the WALANT technique’s long-term safeness has been demonstrated in many studies, there are only few data investigating its short-term effects on tissue perfusion and oxygen levels. It was hypothesized that, temporarily, critical levels of tissue perfusion may occur. Methods Seventeen patients, who were scheduled for different procedures in WALANT technique, were injected with 5–7 ml of 1% Articain containing 1:200,000 epinephrine at the finger base. Capillary-venous oxygen saturation, hemoglobin volume in the capillaries, and relative blood flow in the fingertips were recorded once per second by white light spectrometry and laser Doppler flowmetry before, during and after injection for an average of 32 min. Results Clinically, no persistent tissue malperfusion was observed, and there were no postoperative complications. Capillary-venous oxygen saturation was reduced by ≥ 30% in seven patients. Critical levels of oxygen saturation were detected in four patients during 13 intervals, each lasting for 132.5 s on average. Oxygen saturation returned to noncritical values in all patients by the end of the observation period. Blood flow in the fingertips was reduced by more than 30% in nine patients, but no critical levels were observed, as with the hemoglobin. Three patients demonstrated a reactive increase in blood flow of more than 30% after injection. Conclusions Injection of tumescent local anesthesia containing epinephrine into finger base may temporarily cause a substantial reduction in blood flow and lead to critical levels of oxygen saturation in the fingertips. However, this was fully reversible within minutes and does not cause long-term complications.

scholarly journals Long-term impact of a ten-year intervention program on human and canine Trypanosoma cruzi infection in the Argentine Chaco

2021 ◽  
Vol 15 (5) ◽  
pp. e0009389
Author(s):  
Marta Victoria Cardinal ◽  
Gustavo Fabián Enriquez ◽  
Natalia Paula Macchiaverna ◽  
Hernán Darío Argibay ◽  
María del Pilar Fernández ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Disease Transmission ◽  
Intervention Program ◽  
Substantial Reduction ◽  
Triatoma Infestans ◽  
Incident Case ◽  
Cross Sectional ◽  
Vector Borne ◽  
Long Term Impact

Background Interruption of domestic vector-borne transmission of Trypanosoma cruzi is still an unmet goal in several American countries. In 2007 we launched a long-term intervention program aimed to suppress house infestation with the main domestic vector in southern South America (Triatoma infestans) and domestic transmission in Pampa del Indio, a resource-constrained, hyperendemic municipality with 1446 rural houses inhabited by Creole and indigenous people, in the Argentine Chaco ecoregion. Here, we assessed whether the 10-year insecticide-based program combined with community mobilization blocked vector-borne domestic transmission of T. cruzi to humans and dogs. Methods We carried out two municipality-wide, cross-sectional serosurveys of humans and dogs (considered sentinel animals) during 2016–2017 to compare with baseline data. We used a risk-stratified random sampling design to select 273 study houses; 410 people from 180 households and 492 dogs from 151 houses were examined for antibodies to T. cruzi using at least two serological methods. Results The seroprevalence of T. cruzi in children aged <16 years was 2.5% in 2017 (i.e., 4- to 11-fold lower than before interventions). The mean annual force of child infection (λ) sharply decreased from 2.18 to 0.34 per 100 person-years in 2017. One of 102 children born after interventions was seropositive for T. cruzi; he had lifetime residence in an apparently uninfested house, no outside travel history, and his mother was T. cruzi-seropositive. No incident case was detected among 114 seronegative people of all ages re-examined serologically. Dog seroprevalence was 3.05%. Among native dogs, λ in 2016 (1.21 per 100 dog-years) was 5 times lower than at program onset. Six native adult dogs born after interventions and with stable lifetime residence were T. cruzi-seropositive: three had exposure to T. infestans at their houses and one was an incident case. Conclusions These results support the interruption of vector-borne transmission of T. cruzi to humans in rural Pampa del Indio. Congenital transmission was the most likely source of the only seropositive child born after interventions. Residual transmission to dogs was likely related to transient infestations and other transmission routes. Sustained vector control supplemented with human chemotherapy can lead to a substantial reduction of Chagas disease transmission in the Argentine Chaco.

scholarly journals How does water yield respond to mountain pine beetle infestation in a semiarid forest?

2021 ◽  
Vol 25 (9) ◽  
pp. 4681-4699
Author(s):  
Jianning Ren ◽  
Jennifer C. Adam ◽  
Jeffrey A. Hicke ◽  
Erin J. Hanan ◽  
Christina L. Tague ◽  
...  
Keyword(s):  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
Hydrologic Model ◽  
Water Yield ◽  
Driving Mechanisms ◽  
Mountain Pine ◽  
Pine Beetle ◽  
Interannual Climate Variability ◽  
Hydrologic Responses

Abstract. Mountain pine beetle (MPB) outbreaks in the western United States result in widespread tree mortality, transforming forest structure within watersheds. While there is evidence that these changes can alter the timing and quantity of streamflow, there is substantial variation in both the magnitude and direction of hydrologic responses, and the climatic and environmental mechanisms driving this variation are not well understood. Herein, we coupled an eco-hydrologic model (RHESSys) with a beetle effects model and applied it to a semiarid watershed, Trail Creek, in the Bigwood River basin in central Idaho, USA, to examine how varying degrees of beetle-caused tree mortality influence water yield. Simulation results show that water yield during the first 15 years after beetle outbreak is controlled by interactions between interannual climate variability, the extent of vegetation mortality, and long-term aridity. During wet years, water yield after a beetle outbreak increased with greater tree mortality; this was driven by mortality-caused decreases in evapotranspiration. During dry years, water yield decreased at low-to-medium mortality but increased at high mortality. The mortality threshold for the direction of change was location specific. The change in water yield also varied spatially along aridity gradients during dry years. In wetter areas of the Trail Creek basin, post-outbreak water yield decreased at low mortality (driven by an increase in ground evaporation) and increased when vegetation mortality was greater than 40 % (driven by a decrease in canopy evaporation and transpiration). In contrast, in more water-limited areas, water yield typically decreased after beetle outbreaks, regardless of mortality level (although the driving mechanisms varied). Our findings highlight the complexity and variability of hydrologic responses and suggest that long-term (i.e., multi-decadal mean) aridity can be a useful indicator for the direction of water yield changes after a disturbance.

Stand dynamics and species composition control long-term post-fire trends in evapotranspiration and streamflow from South-eastern Australia’s Temperate Eucalyptus forests

2021 ◽  
Author(s):  
Assaf Inbar ◽  
Richard Benyon ◽  
Patrick Lane ◽  
Shyanika Lakmali ◽  
Shane Haydon ◽  
...  
Keyword(s):  
Species Composition ◽  
Forest Dynamics ◽  
Simulation Analysis ◽  
Stocking Density ◽  
Climatic Conditions ◽  
Water Yield ◽  
Multiple Sources ◽  
Acacia Dealbata ◽  
Eastern Australia

&lt;p&gt;Most of the water that ends up in Melbourne&amp;#8217;s water supply catchments originates from wet Eucalyptus forests that are dominated by Eucalyptus regnans, the tallest known angiosperm on earth. Studies had shown that catchments that are dominated by these forests can experience a significant long-term (&gt;100 years) reduction in streamflow after a stand-replacing fire, which was attributed to higher water-use of the dense overstory regrowth. However, despite several lines of evidence, the direction, extent and duration of post-fire hydrological behaviour vary significantly between catchments and between fire events. Here we propose that this variability is caused by initial stocking density and species composition after the fire, and the climatic conditions that prevail during forest regeneration that affect tree growth and mortality rates. In order to test the hypothesis, we formulated an ecohydrological model that simulates hydrology, growth and forest dynamics of E. regnans and Acacia dealbata, which are known to compete for resources during the initial stages of vegetation recovery. The new model shows high skill in predicting long-term streamflow when compared to observations using multiple sources of data. Simulation analysis shows that the direction, extent and duration of post-fire hydrological behaviour are sensitive to initial stocking density and to the relative abundance of species that regenerate after the fire, which influence the rate of self-thinning during stand development. Furthermore, simulation results show that the observed long-term reduction in streamflow is less likely to occur when the forest would have been less dense before the fire, which theoretically could only occur when a high proportion of the short-lived A. Dealbata regenerated after the previous fire. This highlights the importance of including mechanisms that control the effect of species composition on forest dynamics when modelling the effect of possible future climatic scenarios on water yield.&lt;/p&gt;

Avoidance of Nonanadromous Fish Passage Impedance Caused by Highway Culverts

1996 ◽  
Vol 1559 (1) ◽  
pp. 34-41
Author(s):  
G. Michael Fitch
Keyword(s):  
Flow Velocity ◽  
Fish Passage ◽  
Hydraulic Efficiency ◽  
Normal Flow ◽  
Flow Conditions ◽  
Term Survival ◽  
Wild Trout ◽  
Trout Streams ◽  
Water Depths

Highway culverts may hinder the normal migrations of various trout species in wild trout streams through increased flow velocity, shallow water depths, increased turbulence, and perching. This can impede migrational movements, affecting the genetic diversity and long-term survival of some species. Often, the proper installation of culverts can reduce the adverse effects on fish while maintaining hydraulic efficiency. This study characterized the problems with existing culverts to develop guidelines for the future use of culverts in areas with high gradient streams. Installation criteria will ideally limit the use of bridges where culverts are appropriate, and eliminate the use of culverts where they would create fish passage problems. This will reduce installation, maintenance, and retrofitting costs. The study concluded that culverts can be considered the primary option for crossing trout streams if the culvert can be placed on the same slope as that of the streambed, the slope of the stream is less than 3 percent, the flow velocity does not exceed 1.2 m/sec under normal flow conditions, and the barrel of the culvert can be properly countersunk at the outlet to prevent perching. Bridges should be used at these crossings if any of these criteria cannot be met. The study also concluded that baffles should not be used to control streamflow velocities in newly installed culverts, and concrete aprons should not be used at culvert outlets.

Lung function and respiratory symptoms in a randomized smoking cessation trial of electronic cigarettes

2016 ◽  
Vol 130 (21) ◽  
pp. 1929-1937 ◽  
Author(s):  
Fabio Cibella ◽  
Davide Campagna ◽  
Pasquale Caponnetto ◽  
Maria Domenica Amaradio ◽  
Massimo Caruso ◽  
...  
Keyword(s):  
Smoking Cessation ◽  
Lung Function ◽  
Respiratory Symptoms ◽  
Electronic Cigarettes ◽  
Controlled Trial ◽  
Substantial Reduction ◽  
Cigarette Consumption ◽  
Phenotype Classification ◽  
Quitting Smoking

Quitting smoking is the most important step smokers can take to improve their health. Nonetheless, there is little information on long-term improvements in lung function and/or respiratory symptoms after smoking cessation. Here we illustrate long-term changes in spirometric indices as well as in respiratory symptoms in smokers invited to quit or reduce their cigarette consumption by switching to electronic cigarettes (ECs). Prospective evaluation of cigarette consumption, spirometry and symptoms was performed in a 1-year randomized controlled trial of smokers receiving EC containing 2.4%, 1.8% or 0% nicotine. Spirometric data are presented on the basis of participants’ pooled continuous smoking phenotype classification (Quitters, Reducers, Failures), whereas respiratory symptoms on the basis of their point prevalence-smoking phenotype. Smoking phenotype classification (Quitters, Reducers, Failures) had no significant effect on spirometric indices (FEV1, FVC and FEV1/FVC) with the exception of FEF25–75%, which significantly (P  =0.034) increased over the time among Quitters; their FEF25–75% (% predicted) improving from (means±S.D.) 85.7±15.6% at baseline (BL) to 100.8±14.6%. High prevalence of cough/phlegm (43.1%) and shortness of breath (SoB; 34.8%) was reported at BL with substantial reduction in their frequency at subsequent follow-up visits. These symptoms virtually disappeared very quickly in both quitters and reducers. Smokers invited to switch to ECs who completely abstained from smoking showed steady progressive improvements in their FEF25–75%. Normalization of peripheral airways function was associated with improvement in respiratory symptoms, adding to the notion that abstaining from smoking can reverse tobacco harm in the lung.

Growth Rate and Long-Term Population Dynamics of Jarrah (Eucalyptus marginata Donn ex Sm.) Regeneration in Western Australian Forest

1984 ◽  
Vol 32 (4) ◽  
pp. 353 ◽  
Author(s):  
I Abbott ◽  
O Loneragan
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Intraspecific Competition ◽  
Substantial Reduction ◽  
Eucalyptus Marginata ◽  
Low Intensity ◽  
Rates Of Growth ◽  
Western Australian ◽  
Survival Of Seedlings

Five of the six stages in the regeneration of jarrah (seedling, lignotuberous seedling, seedling coppice, ground coppice and sapling) were studied in detail. Survival of seedlings is variable but usually low, and growth into the ground coppice stage usually takes 15-20 years. Growth into the sapling stage is arrested until there is substantial reduction in intraspecific competition. Lignotuberous seedlings, seedling coppice and ground coppice growing in ashbeds show faster rates of growth in length of the long axis of the lignotuber and length of the tallest shoot. Logging and prescribed (low-intensity) fires are associated with development of more seedling coppice and growth of ground coppice into saplings and poles than is fire alone.

Long-term impacts of forest treatments on water yield: a summary for northeastern USA

1993 ◽  
Vol 150 (2-4) ◽  
pp. 323-344 ◽  
Author(s):  
J.W. Hornbeck ◽  
M.B. Adams ◽  
E.S. Corbett ◽  
E.S. Verry ◽  
J.A. Lynch
Keyword(s):  
Water Yield ◽  
Northeastern Usa

COMPARISON OF MEASURED SOIL 137-CESIUM LOSSES AND EROSION RATES

1987 ◽  
Vol 67 (1) ◽  
pp. 199-203 ◽  
Author(s):  
R. G. KACHANOSKI
Keyword(s):  
Atmospheric Deposition ◽  
Soil Loss ◽  
Accurate Method ◽  
Soil Samples ◽  
Deposition Rates ◽  
Southern Ontario ◽  
Erosion Rates ◽  
Soil Losses ◽  
Runoff Plots

Atmospheric deposition rates of 90Sr and analysis of soil samples from non-eroded sites indicated base levels of total soil 137Cs were approximately 2700 Bq m−2 in southern Ontario in 1985. Measured 137Cs losses (1965–1976) from long-term runoff plots were significantly correlated to measured soil losses during the same period. Monitoring temporal changes in soil 137Cs should be an accurate method of estimating soil loss in southern Ontario. Key words: Soil loss, 137Cs, Ontario, runoff plots

Demography and life cycle of Antarctic krill, Euphausia superba, in the Indian sector of the Southern Ocean: long-term comparison between coastal and open-ocean regions

2000 ◽  
Vol 57 (S3) ◽  
pp. 68-90 ◽  
Author(s):  
E A Pakhomov
Keyword(s):  
Southern Ocean ◽  
Life Span ◽  
Antarctic Krill ◽  
Age Groups ◽  
Substantial Reduction ◽  
Euphausia Superba ◽  
Age Composition ◽  
Indian Sector ◽  
Antarctic Krill Euphausia Superba

Size/age composition and reproductive status of Antarctic krill, Euphausia superba, in the central part of the Indian sector of the Southern Ocean, e.g., the Cooperation Sea (Prydz Bay region) and the Cosmonaut Sea, during austral summers 1977-1990 were summarized to estimate growth rates, longevity, reproduction, recruitment, life span, and mortality rates. The life span of Antarctic krill exceeds 5 years in both the Cosmonaut and Cooperation seas. The age composition of the southern and northern groupings differs markedly, with substantial reduction in numbers of early age groups in the northern grouping. Long-term observations of spawning success, recruitment, and age composition suggest that a self-sustained grouping of krill persists in the Cooperation Sea south of the Antarctic Divergence. However, periodic gene flow via recruits from surrounding regions most probably accounts for the lack of spatial genetic differences between the Cooperation Sea and adjacent areas, thus preventing the establishment of an isolated subpopulation in the region investigated. The major factor responsible for the substantial interannual variability in krill dynamics appears to be macroscale oceanographic and atmospheric circulations, which determine a level of environmental isolation of the Cooperation Sea from adjacent waters.

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