Direct Methods in High Resolution Electron Microscopy

New approaches are proposed to retrieve the wavefunction at the object and from this, to retrieve the projected structure of the object. The wavefunction is retrieved by capturing images at a series of closely spaced focus values and to process the whole 3D data. The structure of the object is retrieved using a formalism based on electron channelling

Organizational error management culture and its impact on performance: a two study replication

The authors argue that a high-organizational error management culture, conceptualized to include norms and common practices in organizations (e.g., communicating about errors, detecting, analyzing, and correcting errors quickly), is pivotal to the reduction of negative and the promotion of positive error consequences. Organizational error management culture was positively related to firm performance across 2 studies conducted in 2 different European countries. On the basis of quantitative and qualitative cross-sectional data from 65 Dutch organizations, Study 1 revealed that organizational error management culture was significantly correlated with both organizational goal achievement and an objective indicator of economic performance. This finding was confirmed in Study 2, using change-of-profitability data from 47 German organizations. The results suggest that organizations may want to introduce organizational error management as a way to boost firm performance

Myelin damage and repair in pathologic CNS: challenges and prospects

Injury to the central nervous system (CNS) results in oligodendrocyte cell death and progressive demyelination. Demyelinated axons undergo considerable physiological changes and molecular reorganizations that collectively result in axonal dysfunction, degeneration and loss of sensory and motor functions. Endogenous adult oligodendrocyte precursor cells (OPCs) and neural stem/progenitor cells (NPCs) contribute to the replacement of oligodendrocytes, however, the extent and quality of endogenous remyelination is suboptimal. Emerging evidence indicates that optimal remyelination is restricted by multiple factors including (i) low levels of factors that promote oligodendrogenesis; (ii) cell death among newly generated oligodendrocytes, (iii) inhibitory factors in the post-injury milieu that impede remyelination, and (iv) deficient expression of key growth factors essential for proper re-construction of a highly organized myelin sheath. Considering these challenges, over the past several years, a number of cell-based strategies have been developed to optimize remyelination therapeutically. Outcomes of these basic and preclinical discoveries are promising and signify the importance of remyelination as a mechanism for improving functions in CNS injuries. In this review, we provide an overview on: 1) the precise organization of myelinated axons and the reciprocal axo-myelin interactions that warrant properly balanced physiological activities within the CNS; 2) underlying cause of demyelination and the structural and functional consequences of demyelination in axons following injury and disease; 3) the endogenous mechanisms of oligodendrocyte replacement; 4) the modulatory role of reactive astrocytes and inflammatory cells in remyelination; and 5) the current status of cell-based therapies for promoting remyelination. Careful elucidation of the cellular and molecular mechanisms of demyelination in the pathologic CNS is a key to better understanding the impact of remyelinati

Long-term tillage, straw management and N fertilizer rate effects on crop yield, N uptake and N balance sheet in a Black Chernozem

Non-Peer ReviewedA field experiment (established in autumn 1979, with monoculture barley [1980-1990] and barley/wheat-canola-triticale-pea rotation [1991-2008]) was conducted on a Black Chernozem [Albic Agricryoll] silty clay loam soil at Ellerslie, Alberta, to determine the influence of tillage (zero tillage [ZT] and conventional tillage [CT]), straw management (straw removed [SRem] and straw retained [SRet]) and N fertilizer rate (0, 50 and 100 kg N ha-1 in SRet, and only 0 kg N ha-1 in SRem plots) on seed yield, straw yield, total N uptake in seed + straw (1991-2008), and N balance sheet (1980-2008). The N fertilizer urea was midrow-banded under both tillage systems in the 1991-2008 period. There was a considerable increase in yield and total N uptake up to 100 kg N ha-1 under both tillage systems. On the average, CT produced greater seed yield (by 332 kg ha-1), straw yield (by 323 kg ha-1) and total N uptake (by 6.3 kg N ha-1) than ZT. Compared to SRem treatment, seed yield, straw yield and total N uptake tended to be greater with SRet at the zero-N rate used in the study. The amounts of applied N unaccounted for over the 1980-2008 period ranged from 845 to 1665 kg N ha-1, suggesting a great potential for N loss from the soil-plant system through denitrification, and N immobilization from the soil mineral N pool. In conclusion, crop yield and N uptake were lower under ZT than CT, and long-term retention of straw suggests some gradual improvement in soil productivity

Long-term tillage, straw management, and N fertilizer rate effects on crop yield, N uptake, and N balance sheet in a Gray Luvisol

Non-Peer ReviewedA field experiment (established in autumn 1979, with monoculture barley [1980-1990] and barley/wheat-canola-triticale-pea rotation [1991-2008] was conducted on a Gray Luvisol [Typic Haplocryalf] loam soil at Breton, Alberta, to determine the influence of tillage (zero tillage [ZT] and conventional tillage [CT]), straw management (straw removed [SRem] and straw retained [SRet]) and N fertilizer rate (0, 50 and 100 kg N ha-1 in SRet, and only 0 kg N ha-1 in SRem plots) on seed yield, straw yield, total N uptake in seed + straw (1991-2008), and N balance sheet (1980- 2008). The N fertilizer urea was midrow-banded under both tillage systems in the 1991-2008 period. There was a considerable increase in yield and total N uptake up to 100 kg N ha-1 under both tillage systems. On the average, CT produced greater seed yield (by 223 kg ha-1), straw yield (by 177 kg ha-1) and total N uptake (by 5.6 kg N ha-1) than ZT. Compared to SRem treatment, seed yield, straw yield and total N uptake tended to be greater with SRet at the zero-N rate used in the study. The amounts of applied N unaccounted for over the 1980-2008 period ranged from 845 to 1665 kg N ha-1, suggesting a great potential for N loss from the soil-plant system through denitrification, and N immobilization from the soil mineral N pool. In conclusion, crop yield and N uptake were lower under ZT than CT, and long-term retention of straw suggests some gradual improvement in soil productivity

Long-term tillage, straw management, and N fertilizer rate effects on crop yield, N uptake, and N balance sheet in a Gray Luvisol

Non-Peer ReviewedA field experiment (established in autumn 1979, with monoculture barley [1980-1990] and barley/wheat-canola-triticale-pea rotation [1991-2008] was conducted on a Gray Luvisol [Typic Haplocryalf] loam soil at Breton, Alberta, to determine the influence of tillage (zero tillage [ZT] and conventional tillage [CT]), straw management (straw removed [SRem] and straw retained [SRet]) and N fertilizer rate (0, 50 and 100 kg N ha-1 in SRet, and only 0 kg N ha-1 in SRem plots) on seed yield, straw yield, total N uptake in seed + straw (1991-2008), and N balance sheet (1980- 2008). The N fertilizer urea was midrow-banded under both tillage systems in the 1991-2008 period. There was a considerable increase in yield and total N uptake up to 100 kg N ha-1 under both tillage systems. On the average, CT produced greater seed yield (by 223 kg ha-1), straw yield (by 177 kg ha-1) and total N uptake (by 5.6 kg N ha-1) than ZT. Compared to SRem treatment, seed yield, straw yield and total N uptake tended to be greater with SRet at the zero-N rate used in the study. The amounts of applied N unaccounted for over the 1980-2008 period ranged from 845 to 1665 kg N ha-1, suggesting a great potential for N loss from the soil-plant system through denitrification, and N immobilization from the soil mineral N pool. In conclusion, crop yield and N uptake were lower under ZT than CT, and long-term retention of straw suggests some gradual improvement in soil productivity