A Method to Determine Long-Term Anaerobic Carbon and Nutrient Mineralization in Soils

2015 ◽  
pp. 209-219 ◽  
Author(s):  
Karen Updegraff ◽  
Scott D. Brigham ◽  
John Pastor ◽  
Carol A. Johnston
Keyword(s):  
Nutrient Mineralization

scholarly journals Long-Term Growth of Alfalfa Increased Soil Organic Matter Accumulation and Nutrient Mineralization in a Semi-Arid Environment

2021 ◽  
Vol 9 ◽  
Author(s):  
Xin Song ◽  
Chao Fang ◽  
Zi-Qiang Yuan ◽  
Feng-Min Li
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Nutrients ◽  
Root Biomass ◽  
Sweet Clover ◽  
The Loess Plateau ◽  
Biomass Density ◽  
Nutrient Mineralization ◽  
Semi Arid

Land use patterns and vegetation coverage in semi-arid areas of the Loess Plateau have undergone great changes due to the implementation of the “Grain for Green” project. The introduction of legume pasture species, such as alfalfa (Medicago sativa L.) and sweet clover (Melilotus officinalis L.), is one of the most efficient methods of vegetation restoration and reconstruction in this region. However, there is a need for an effective assessment of the root system distribution and its interaction with soil after long-term introduction. An experiment involving the introduction of alfalfa and sweet clover on abandoned farmlands was initiated in 2003 to assess the long-term effects. After 17 years, root and soil samples at depths of 0–20 and 20–60 cm were collected to characterize the root biomass, root carbon (C), nitrogen (N), and phosphorus (P), soil microbial biomass carbon (MBC) and nitrogen (MBN), soil organic carbon (SOC), and soil N and P. The results showed that the root biomass density of alfalfa in the 0–20 and 20–60 cm layers (63.72 and 12.27 kg m–3, respectively) were significantly higher than for sweet clover (37.43 and 8.97 kg m–3, respectively) and under natural abandonment (38.92 and 9.73 kg m–3, respectively). The SOC, total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), nitrate-nitrogen (NO3–-N), MBC and MBN in the 0–20 and 20–60 cm layers were higher after alfalfa introduction compared with sweet clover introduction and natural abandonment, although the ammonia-nitrogen (NH4+-N) concentration in the 0–20 cm layer was lower. There were significantly positive correlations between root biomass density and both soil nutrients and microbial biomass, while there was a negative correlation between the soil NH4+-N and root biomass density. These results indicate that alfalfa root growth improved soil organic matter accumulation and nutrient mineralization. The accumulation and mineralization of soil nutrients also guaranteed root and microorganism growth. Therefore, it was concluded that alfalfa introduction will promote soil nutrients immobilization and mineralization and may enable sustainable land use in the semi-arid region of the Loess Plateau, China.

scholarly journals Phenological shifts in lake stratification under climate change

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
R. Iestyn Woolway ◽  
Sapna Sharma ◽  
Gesa A. Weyhenmeyer ◽  
Andrey Debolskiy ◽  
Malgorzata Golub ◽  
...  
Keyword(s):  
Climate Model ◽  
Greenhouse Gas Emission ◽  
Phosphorus Release ◽  
Global Changes ◽  
Lake Ecosystems ◽  
Nutrient Mineralization ◽  
Phenological Shifts ◽  
Ecological Importance ◽  
Lake Stratification

AbstractOne of the most important physical characteristics driving lifecycle events in lakes is stratification. Already subtle variations in the timing of stratification onset and break-up (phenology) are known to have major ecological effects, mainly by determining the availability of light, nutrients, carbon and oxygen to organisms. Despite its ecological importance, historic and future global changes in stratification phenology are unknown. Here, we used a lake-climate model ensemble and long-term observational data, to investigate changes in lake stratification phenology across the Northern Hemisphere from 1901 to 2099. Under the high-greenhouse-gas-emission scenario, stratification will begin 22.0 ± 7.0 days earlier and end 11.3 ± 4.7 days later by the end of this century. It is very likely that this 33.3 ± 11.7 day prolongation in stratification will accelerate lake deoxygenation with subsequent effects on nutrient mineralization and phosphorus release from lake sediments. Further misalignment of lifecycle events, with possible irreversible changes for lake ecosystems, is also likely.

Therapy and prevention for mental health: What if mental diseases are mostly not brain disorders?

2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis
Keyword(s):  
Mental Health ◽  
Mental Disease ◽  
Brain Disorders ◽  
Social Stressors ◽  
Labor Education ◽  
Mental Diseases ◽  
Long Term Follow Up ◽  
Political Decisions

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

Brief summary of Kleť photographic search programme for minor planets

1999 ◽  
Vol 173 ◽  
pp. 189-192
Author(s):  
J. Tichá ◽  
M. Tichý ◽  
Z. Moravec
Keyword(s):  
Ccd Camera ◽  
Minor Planet ◽  
Minor Planets ◽  
Main Belt

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Unusual Intranuclear Structures in Chick Sympathetic Neurons

1967 ◽  
Vol 25 ◽  
pp. 188-189
Author(s):  
E. B. Masurovsky ◽  
H. H. Benitez ◽  
M. R. Murray
Keyword(s):  
Electron Microscope ◽  
Sympathetic Neurons ◽  
Uranyl Acetate ◽  
Sympathetic Ganglia ◽  
Lead Citrate ◽  
Thin Sections ◽  
Cns Neurons ◽  
Mammalian Cns

Recent light- and electron microscope studies concerned with the effects of D2O on the development of chick sympathetic ganglia in long-term, organized culture revealed the presence of rod-like fibrillar formations, and associated granulofibrillar bodies, in the nuclei of control and deuterated neurons. Similar fibrillar formations have been reported in the nuclei of certain mammalian CNS neurons; however, related granulofibrillar bodies have not been previously described. Both kinds of intranuclear structures are observed in cultures fixed either in veronal acetate-buffered 2%OsO4 (pH 7. 4), or in 3.5% glutaraldehyde followed by post-osmication. Thin sections from such Epon-embedded cultures were stained with ethanolic uranyl acetate and basic lead citrate for viewing in the electron microscope.

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