Evaluating energy efficiency of site-specific tillage in maize in NE Italy

This paper examine the efficiency of energy use of three conservation tillage practices (SST - sub-soil tillage; MT - minimum tillage; and NT - no tillage) performed within two management zones, previously identified in a field according to the stability of yield variability. Experiments were carried out in 2003 in NE Italy, on a farm near Rovigo, on a 8-ha field with clay soil, in maize (Zea mays, L.). The purpose of the paper is (i) to investigate the energy variability due to these tillage practices performed spatially within two management zones and (ii) to analyze the long-term energetic efficiency for each tillage practice. The energy balance was highest for SST with respect to MT and NT, due to labor and fuel consumption rates. The energy balance was influenced by the spatial pattern of yield, with appreciable differences between practices in terms of both the conversion index of energy for tillage (9.0, 12.6 and 22.8GJha(-1) for SST, MT and NT, respectively) and the energy use efficiency for tillage (8.0, 11.6, 21.8GJha(-1) for SST, MT and NT, respectively). Based on the simulated data and the calibration results, SALUS model proved to be a good tool for analyzing long-term effects of tillage practices on yield. The NT treatment showed the best efficiency over years, due to the low inputs in comparison with the output level.     

Differential response of linear and angular psoralens in PUVA-induced apoptosis in HL-60 cells.

Treatment of cells with UVA radiation in combination with linear psoralens induces a cell-cycle block and subsequent apoptosis, whereas angular derivatives produce apoptosis without affecting the cellular cycle.     

Modification of the suppressor phenotype of thymine requiring strains of Escherichia coli.

Thymine requiring strains of Escherichia coli suppress nonsense and frameshift mutations during translation. Strains with different genetic backgrounds exhibited different nonsense suppression spectra and showed differences in the apparent suppression efficiency. Part of this strain difference is due to a presumably novel gene (tsmA) mapping near 39 min. This gene affects the spectrum and apparent efficiency of suppression, and appears to affect the utilization of thymidine.     

Effect of a light pulse during the dark on photoperiodic regulation of the rate of thyroxine-induced, spontaneous, and prolactin-inhibited metamorphosis in Rana pipiens tadpoles

Since Rana pipiens tadpoles injected with thyroxine (T4) early in the dark develop more slowly than those injected in the light, we studied the effect of giving a light pulse of 1 hr early in the dark. Tadpoles injected under a 7.5-W red light bulb in a darkened room with 0.2 microgram T4 daily at 2200 hr went through metamorphosis faster on a 12L:3D:1L:8D cycle with a light pulse after injection than on a 12L:12D cycle without a light pulse, and even faster on a 12L:1.5D:1L:9.5D cycle with a light pulse before the injection. Thus a 1-hr light pulse counteracted the metamorphic delay resulting from administration of T4 in the dark, and set in motion the conditions that resulted in a more rapid response to an injection of T4. However, a 1-hr light pulse in the early dark had no effect on growth and development of older or younger untreated tadpoles or those constantly immersed in 30 micrograms/liter T4. Larvae on 21L:3D with T4 injection in the dark and on 12L:3D:1L:8D with T4 injection at 0700 hr just before the start of the main light phase progressed faster than 12L:3D:1L:8D with injection at 2200 hr in the dark before only a 1-hr light pulse. Thus the length of the light phase immediately after T4 injection was significant. There was no difference on 12L:12D and 12L:3D:1L:8D cycles in the effectiveness of daily injections of 10 micrograms prolactin (PRL) in the early dark at 2200 hr in promoting tail growth or antagonizing tail resorption induced by T4 immersion. Under these conditions, PRL utilization did not appear to be inhibited by the light pulse.     

Immune imbalance in the synovial fluid of rheumatoid arthritis patients: effects of intra-articular injection of thymopentin.

T cell subsets in the synovial fluid (SF) and peripheral blood (PB) of RA patients and controls suffering from different forms of chronic synovitis have been investigated. The immunological evaluation showed a reduction of CD4 subsets in RA-SF compared to RA-PB (p less than 0.001), and an almost complete absence of the suppressor-inducer/naive T cells in RA-SF compared to RA-PB and SF from patients with other forms of chronic synovitis. The CD8 subpopulation showed an increased proportion of cytotoxic cells only in RA-SF. On the basis of these results, an intra-articular immunomodulating treatment with thymopentin has been performed: its effects were characterized by an increase of CD8+CD11b+ T cells in the CD8 subset parallel to the enhancement of the suppressor-inducer/naive T cells in the CD4 subset with a statistically significant correlation. The enhanced levels of soluble CD8 decreased after treatment in RA-SF, whereas the soluble IL-2R levels were not significantly modified. Clinical evaluation showed a significative amelioration in all considered parameters.     

Combining molecular dynamics and docking simulations of the cytidine deaminase from Mycobacterium tuberculosis H37Rv

Cytidine Deaminase (CD) is an evolutionarily conserved enzyme that participates in the pyrimidine salvage pathway recycling cytidine and deoxycytidine into uridine and deoxyuridine, respectively. Here, our goal is to apply computational techniques in the pursuit of potential inhibitors of Mycobacterium tuberculosis CD (MtCDA) enzyme activity. Molecular docking simulation was applied to find the possible hit compounds. Molecular dynamics simulations were also carried out to investigate the physically relevant motions involved in the protein-ligand recognition process, aiming at providing estimates for free energy of binding. The proposed approach was capable of identifying a potential inhibitor, which was experimentally confirmed by IC₅₀ evaluation. Our findings open up the possibility to extend this protocol to different databases in order to find new potential inhibitors for promising targets based on a rational drug design process.     

Accumulation of putrescine and related amino acids in potassium deficient Sesamum

Sesamum indicum was grown in complete or potassium deficient nutrient solution and amino acids, amines, nitrogen and potassium were determined weekly in the leaves. The incorporation of l-arginine-[U-¹⁴C] into protein was also followed. The interconversions of the amino acids of the ordithine-urea cycle, and their contribution to the formation of amines, were studied in cell-free extracts and intact leaves using labelled amino acids. As the level of potassium in the leaves decreased, the levels of the amino acids ornithine, citrulline and arginine, and of the amines putrescine, N-carbamylputrescine and agmatine increased. Potassium deficiency also reduced the rate of protein synthesis. Putrescine appears to be formed preferentially from citrulline with N-carbamylputrescine as intermediate.     

COX16 is required for assembly of cytochrome c oxidase in human cells and is involved in copper delivery to COX2

Cytochrome c oxidase (COX), complex IV of the mitochondrial respiratory chain, is comprised of 14 structural subunits, several prosthetic groups and metal cofactors, among which copper. Its biosynthesis involves a number of ancillary proteins, encoded by the COX-assembly genes that are required for the stabilization and membrane insertion of the nascent polypeptides, the synthesis of the prosthetic groups, and the delivery of the metal cofactors, in particular of copper. Recently, a modular model for COX assembly has been proposed, based on the sequential incorporation of different assembly modules formed by specific subunits.We have cloned and characterized the human homologue of yeast COX16. We show that human COX16 encodes a small mitochondrial transmembrane protein that faces the intermembrane space and is highly expressed in skeletal and cardiac muscle. Its knockdown in C. elegans produces COX deficiency, and its ablation in HEK293 cells impairs COX assembly. Interestingly, COX16 knockout cells retain significant COX activity, suggesting that the function of COX16 is partially redundant.Analysis of steady-state levels of COX subunits and of assembly intermediates by Blue-Native gels shows a pattern similar to that reported in cells lacking COX18, suggesting that COX16 is required for the formation of the COX2 subassembly module. Moreover, COX16 co-immunoprecipitates with COX2. Finally, we found that copper supplementation increases COX activity and restores normal steady state levels of COX subunits in COX16 knockout cells, indicating that, even in the absence of a canonical copper binding motif, COX16 could be involved in copper delivery to COX2.