Correspondent Control Research Articles

MACRONUTRIENTS USE EFFICIENCY IN SANDY SOIL CULTIVATED BY MAGNETICALLY TREATED SEEDS PRE-SOWING AND SPRAYED BY N-FERTILIZER DISSOLVED IN MAGNETIZED WATER

Purpose: is to enhance the nutrients use efficiency (NUE) along with the crop yield and quality by magnetic treatment (MT) of the groundnut (Arachis hypogaea L.) seeds pre-sowing as well as the MT of water used to dissolve the nitrogen (N) fertilizer under sandy soil field conditions. Methods: Treatments were distributed in a split-plots design in triplicates. The control CL has received the recommended dose RD of the N-fertilizer while other treatments received a 50% of the RD applied to the surface soil 30 days after planting. The main factor (F1) was the N-application rates 1000, 2000, and 3000 mg kg-1 of urea dissolved in the magnetically treated water (MTW) then sprayed on the soil in the liquid form five times after planting. The sub-factor (F2) was the time of MT (15, 30, and 45 min) of the groundnut seeds exposed to a magnetic field MF 1.4 T intensity before planting. Results: The soil available N, P, K, Fe, Mn, and Zn (mg kg-1) were increased significantly by 34.8%, 23.0%, 3.49%, 9.4%, 22.2%, and 23.2% respectively, at P ≤ 0.05 by the 45 min MT and 3000 mg kg-1 N relative to its corresponding control (CL). The MT has increased the seeds yield (kg ha-1) significantly in the order 45 min >30 min >15 min for the N-rates 1000, 2000, and 3000 mg kg-1. At the 45-min time, it was increased by 17.5, 15.3, and 14.8% for the N-rates, respectively. Conclusions: The 2000 mg kg-1 rate with MT of seeds for 15 min can be recommended for an acceptable nutrients use efficiency (NUE).

Effect of the long-term application of organic matter on soil carbon accumulation and GHG emissions from a rice paddy field in a cool-temperate region, Japan-II. Effect of different compost applications-

ABSTRACT The influence of long-term application of different types of compost on rice grain yield, CH4 and N2O emissions, and soil carbon storage (0 − 30 cm) in rice paddy fields was clarified. Two sets of paddy fields applied with rice straw compost or livestock manure compost mainly derived from cattle were used in this study. Each set comprised long-term application (LT) and corresponding control (CT) plots. The application rates for rice straw compost (42 years) and livestock manure compost (41 years in total with different application rates) were 20 Mg fresh weight ha–1. Soil carbon storage increased by 33% and 37% with long-term application of rice straw compost and livestock manure compost, respectively. The soil carbon sequestration rate by the organic matter application was 23% higher with the livestock manure compost than with the rice straw compost. The rice grain yield in the LT plot was significantly higher than that in the corresponding CT plot with both types of compost. Although the difference was not significant in the rice straw compost, cumulative CH4 emissions increased with long-term application of both composts. Increase rate of CH4 emission with long-term application was higher in the livestock manure compost (99%) than that in the rice straw compost (26%). In both composts, the long-term application did not increase N2O emission significantly. As with the rice straw compost, the increase in CH4 emission with the long-term application of livestock manure compost exceeded the soil carbon sequestration rate, and the change in the net greenhouse gas (GHG) balance calculated by the difference between them was positive, indicating a net increase in the GHG emissions. The increase in CH4 and net GHG emissions owing to the long-term application of the livestock manure compost could be higher than that of the rice straw compost owing to the amount of applied carbon, the quality of compost and the soil carbon accumulation. The possibility that carbon sequestration in the subsoil differs depending on the type of composts suggests the importance of including subsoil in the evaluation of soil carbon sequestration by long-term application of organic matter.

Absence of glucose transporter 4 diminishes electrical activity of mouse hearts during hypoxia

Insulin resistance, which characterizes type 2 diabetes, is associated with reduced translocation of glucose transporter 4 (GLUT4) to the plasma membrane following insulin stimulation, and diabetic patients with insulin resistance show a higher incidence of ischaemia, arrhythmias and sudden cardiac death. The aim of this study was to examine whether GLUT4 deficiency leads to more severe alterations in cardiac electrical activity during cardiac stress due to hypoxia. To fulfil this aim, we compared cardiac electrical activity from cardiac-selective GLUT4-ablated (G4H-/-) mouse hearts and corresponding control (CTL) littermates. A custom-made cylindrical 'cage' electrode array measured potentials (Ves) from the epicardium of isolated, perfused mouse hearts. The normalized average of the maximal downstroke of Ves ( (|d Ves/dt(min)|na), which we previously introduced as an index of electrical activity in normal, ischaemic and hypoxic hearts, was used to assess the effects of GLUT4 deficiency on electrical activity. The |d Ves/dt(min)|na of G4H −/− and CTL hearts decreased by 75 and 47%, respectively (P < 0.05), 30 min after the onset of hypoxia. Administration of insulin attenuated decreases in values of |d Ves/dt(min)|na in G4H −/− hearts as well as in CTL hearts, during hypoxia. In general, however, G4H −/− hearts showed a severe alteration of the propagation sequence and a prolonged total activation time. Results of this study demonstrate that reduced glucose availability associated with insulin resistance and a reduction in GLUT4-mediated glucose transport impairs electrical activity during hypoxia, and may contribute to cardiac vulnerability to arrhythmias in diabetic patients.

Plasma iron levels appraised 15 days after spinal cord injury in a limb movement animal model

Experimental, controlled trial. The purpose of this study was to evaluate plasma iron and transferrin levels in a limb movement animal model with spinal cord injury (SCI). Universidade Federal de São Paulo, Departamento de Psicobiologia. In all, 72 male Wistar rats aged 90 days were divided into four groups: (1) acute SCI (1 day, SCI1), (2) 3 days post-SCI (SCI3), (3) 7 days post-SCI (SCI7) and (4) 15 days post-SCI (SCI15). Each of these groups had corresponding control (CTRL) and SHAM groups. Plasma iron and transferrin levels of the different groups were analyzed using a one-way analysis of variance (ANOVA) followed by Tukey's test. We found a significant reduction in iron plasma levels after SCI compared with the CTRL group: SCI1 (CTRL: 175±10.58 μg dl(-1); SCI: 108.28±11.7 μg dl(-1)), SCI3 (CTRL: 195.5±11.00 μg dl(-1); SCI: 127.88±12.63 μg dl(-1)), SCI7 (CTRL: 186±2.97 μg dl(-1); SCI: 89.2±15.39 μg dl(-1)) and SCI15 (CTRL: 163±5.48 μg dl(-1); SCI: 124.44±10.30 μg dl(-1)) (P<0.05; ANOVA). The SHAM1 group demonstrated a reduction in iron plasma after acute SCI (CTRL: 175±10.58 μg dl(-1); SHAM: 114.60±7.81 μg dl(-1)) (P<0.05; ANOVA). Reduced iron metabolism after SCI may be one of the mechanisms involved in the pathogenesis of sleep-related movement disorders.

Metabolic, enzymatic and endocrine status in high-yielding dairy cows--Part 2.

Pairs of 29 high-yielding (HC) dairy cows (> or = 45 kg/day reached at least once during lactation) and 29 corresponding control (CC) cows (with milk yields representing the average yield of the herds) were studied in 29 Swiss farms from March 1995 to September 1996. The hypothesis tested was that there are differences in metabolic, enzymatic and endocrine status between HC and CC cows. Cows were studied 2 weeks before and at 5, 9, 13, 17 and 40 weeks post-partum. Concentrations of metabolites, minerals and hormones and enzyme activities were in the normal range in both HC and CC cows. Changes in metabolic and endocrine traits in early lactation expressed insufficient energy intake, but were similar in both HC and CC cows. Homeorhetic and homeostatic control of metabolism in HC cows was thus adequate to adjust to and allow high milk yields. Under adequate husbandry, management and feeding conditions, metabolic disease problems in HC cows [10,500 kg energy-corrected milk (ECM)/lactation, peak yields of > or = 45 kg ECM/day] can be avoided.

Effect of Prerigor Pressurization on the Activity of Calcium‐Activated Factor

ABSTRACTCrude calcium‐activated factor (CAF) was prepared from pre‐rigor pressurized (PRP) and corresponding control (CON) bovine muscles at 0, 1, and 3 days of postmortem times. Throughout these periods, PRP samples had consistently lower total CAF activity than CON. Yet, it seems probable that PRP caused a transient increase in Ca++ sufficient to activate CAF for a brief period of time because (1) early postmortem, PRP muscle had quantities of a 95,000‐dalton component presumably produced by CAF; (2) Z‐lines from at‐death PRP muscles were highly degraded; (3) very early postmortem storage, the SDS‐electrophoretic patterns of PRP myofibrils resembled that of CAF‐treated myotibrils. CAF autolysis may account for the low CAF activity observed in PRP muscles at later postmortem storage times.