Increased proportion of active soil N in Breton loam under cropping systems with forages and green manures

Total soil N and N mineralization rate partially ctririct&iie the influence olvariouJcropping systems on the growth of.sequent.crop.s in a rotation' The objectives of this study were to (1) quantify the relationship among cropping system, total N and mineralizable N, and (2) compare amount of N mineralized under'controlled laboratory conditions-with pianl N uptake under green]ouse conditi:ns. Three cropping systems that have been in operation between 9 and 60 yr on a Gray-Luvisol (Breton loam; were ^selected . They included: (1) an ag.lo: ecological (lnn) d-yr rotation involving fabibeans as gr-een manure (AER1 sampled after the_first lababean crop-?nq AER? ,u-pied after 3 yr of continuous forage)l (2) continuous grain system (CG), with fertilizer N at 90 kg ha-'^yr- '; inttrated in 1980 and considered established in f"98i; i3) a classicial Ereton iotation (CBR) involving 9]o-ng-term (ca. 1930) 5-yr rotation with forages and cereals and no return of.ciop residues (CBR1 fertilized with P-K-S and CBR2 unfertilized). We cautio_n that not all ohlses of each rotation were sampled: bur conclusions pertain to N-mineralization potential in soil samples immediately preceding barley as sequent crop in each rotation. The rate ofN mineralization declined with time, but it remained greater than iero aftei 20 wi AER2 > > CBRI > CBR2 : CG. Mineralizable soil N, following one cycle of the AER rotation, was almost double that following 60 yr of the CBR rotation. Data for mineral-N accumulation under laboratory conditions were described best by a single-component expo-n-ential model. Legume-based rotations were associated with increased total soil N and a greater proportional increase in active N than in total soilN. Active N was least in soil under the CG system. The incubation-extraction procedure resulted in higher estimates of mineralizable N than did the plant-uptake method; liowever, the ranking of N-supplying power of soils was the same

Improved soil quality and barley yields with fababeans, manure, forages and crop rotation on a Gray Luvisol

There exists a need (i) to test, whether equal or better cereal yields could be obtained using cropping systems which rely on renewable resources rather than on fertilizer nitrogen; and (ii) to discover the condition of the soil resource under these systems.The long-term cropping systems on a Gray Luvisol at Breton were studied. They included: (i) an agro-ecological 8-yr rotation (AER), established in 1981, which involved addition of both fababean green manure and manure from livestock fed with forages and fababeans grown in the rotation: (ii) a continuous grain (barley) system (CG), with fertilizer N at 90 kg ha−1 y−1, established in 1981; (iii) a classical Breton 5-yr rotation (CBR) involving forages and cereals, with no return of crop residues or manure, established in 1930. Mean barley yields were 16–19% higher in the AER (P ≤ 0.05) than in the CG system, and yield on either was about double that of the CBR. Within 9 yr, there was evidence of increased total C, N, and P; available N, P and K, CEC; microbial biomass, microbial respiration; and counts of bacteria, fungi, and mycorrhizae in the AER compared with the CG system.We conclude that biological fixation of N by legumes can be used as the sole source of N for barley production on Luvisolic soils of low fertility such as the Breton loam, without sacrificing yield or soil quality. Barley yields in the AER (38% of the rotation time) exceeded those of barley grown under continuous cereal cropping. The soil resource was maintained or improved during a 10-yr period under AER compared to the CG or CBR systems. Further research is needed to discover the mechanisms involved in regulating biological activity and availability of plant nutrients other than N in the AER system. Key words: Barley, Breton loam, cropping systems, Gray Luvisol, soil quality, fababean

Synonymous GATA2 mutations result in selective loss of mutated RNA and are common in patients with GATA2 deficiency

Deficiency of the transcription factor GATA2 is a highly penetrant genetic disorder predisposing to myelodysplastic syndromes (MDS) and immunodeficiency. It has been recognized as the most common cause underlying primary MDS in children. Triggered by the discovery of a recurrent synonymous GATA2 variant, we systematically investigated 911 patients with phenotype of pediatric MDS or cellular deficiencies for the presence of synonymous alterations in GATA2. In total, we identified nine individuals with five heterozygous synonymous mutations: c.351C>G, p.T117T (N = 4); c.649C>T, p.L217L; c.981G>A, p.G327G; c.1023C>T, p.A341A; and c.1416G>A, p.P472P (N = 2). They accounted for 8.2% (9/110) of cases with GATA2 deficiency in our cohort and resulted in selective loss of mutant RNA. While for the hotspot mutation (c.351C>G) a splicing error leading to RNA and protein reduction was identified, severe, likely late stage RNA loss without splicing disruption was found for other mutations. Finally, the synonymous mutations did not alter protein function or stability. In summary, synonymous GATA2 substitutions are a new common cause of GATA2 deficiency. These findings have broad implications for genetic counseling and pathogenic variant discovery in Mendelian disorders

Synonymous GATA2 mutations result in selective loss of mutated RNA and are common in patients with GATA2 deficiency

Deficiency of the transcription factor GATA2 is a highly penetrant genetic disorder predisposing to myelodysplastic syndromes (MDS) and immunodeficiency. It has been recognized as the most common cause underlying primary MDS in children. Triggered by the discovery of a recurrent synonymousGATA2variant, we systematically investigated 911 patients with phenotype of pediatric MDS or cellular deficiencies for the presence of synonymous alterations inGATA2. In total, we identified nine individuals with five heterozygous synonymous mutations: c.351C>G, p.T117T (N = 4); c.649C>T, p.L217L; c.981G>A, p.G327G; c.1023C>T, p.A341A; and c.1416G>A, p.P472P (N = 2). They accounted for 8.2% (9/110) of cases with GATA2 deficiency in our cohort and resulted in selective loss of mutant RNA. While for the hotspot mutation (c.351C>G) a splicing error leading to RNA and protein reduction was identified, severe, likely late stage RNA loss without splicing disruption was found for other mutations. Finally, the synonymous mutations did not alter protein function or stability. In summary, synonymousGATA2substitutions are a new common cause of GATA2 deficiency. These findings have broad implications for genetic counseling and pathogenic variant discovery in Mendelian disorders

The Earth: Plasma Sources, Losses, and Transport Processes

This paper reviews the state of knowledge concerning the source of magnetospheric plasma at Earth. Source of plasma, its acceleration and transport throughout the system, its consequences on system dynamics, and its loss are all discussed. Both observational and modeling advances since the last time this subject was covered in detail (Hultqvist et al., Magnetospheric Plasma Sources and Losses, 1999) are addressed

The Physical Processes of CME/ICME Evolution

As observed in Thomson-scattered white light, coronal mass ejections (CMEs) are manifest as large-scale expulsions of plasma magnetically driven from the corona in the most energetic eruptions from the Sun. It remains a tantalizing mystery as to how these erupting magnetic fields evolve to form the complex structures we observe in the solar wind at Earth. Here, we strive to provide a fresh perspective on the post-eruption and interplanetary evolution of CMEs, focusing on the physical processes that define the many complex interactions of the ejected plasma with its surroundings as it departs the corona and propagates through the heliosphere. We summarize the ways CMEs and their interplanetary CMEs (ICMEs) are rotated, reconfigured, deformed, deflected, decelerated and disguised during their journey through the solar wind. This study then leads to consideration of how structures originating in coronal eruptions can be connected to their far removed interplanetary counterparts. Given that ICMEs are the drivers of most geomagnetic storms (and the sole driver of extreme storms), this work provides a guide to the processes that must be considered in making space weather forecasts from remote observations of the corona.Peer reviewe