N0 Level Research Articles

Analysis of grain yield and its components in spring triticale under different N fertilization regimes

Grain yield is a result of an organized interplay of several yield components, which are highly susceptible to environmental fluctuations. However, there is still a lack of knowledge about the relationship between grain yield and factors governing it. Experiments were conducted during the period 2008–2011 at the Institute of Agriculture, Lithuanian Research Centre for Agriculture and Forestry in Central Lithuania (55023′50′′ N and 23051′40′′ E) on an Endocalcari-Endohypogleyic Cambisol (CMg-n-w-can). The correlation coefficients and path coefficient analysis was done: i) to study the interrelationship between spring triticale grain yield and its components under different N fertilization regimes, ii) to establish the impact of meteorological factors on them, iii) to explain the causality of associations between the mentioned parameters through direct and indirect effects. Three nitrogen levels were used: i) without nitrogen (N0), ii) N applied as basic fertilization shortly before sowing (N60-180), iii) N90 and N150 rates split in two and three applications. Grain yield, yield components (ears m-2, grains ear-1, thousand grain weight) and meteorological factors were investigated. The results demonstrated that the interrelationship between grain yield and its components differed between N fertilization levels. Under single N60-180 fertilization, grain yield of spring triticale depended on ears m-2 and a thousand grain weight. Under split N90, N150 level the yield depended on ears m-2. The correlation matrix between spring triticale grain yield and yield components did not reveal significant causality at N0 level. The character of interaction of grain yield components influenced the grain yield by 17.2% and 28.3% at single N60-180 and split N90, N150 fertilization levels, respectively. However, such interaction was insignificant at N0 level. The growth and development of spring triticale responded to meteorological conditions more sensitively at single N60-180 and split N90, N150 levels than at N0 level. At all N regimes, the weather conditions caused 72.6–83.5% of ears m-2, 46.6–94.1% of grains ear-1 and 84.5–92.7% of thousand grain weight data variation. The interaction of all meteorological factors influenced the grain yield by 25.6% and 40.7% at N60-180 and split N90, N150 levels, respectively.

The effects of scenario-based simulation course training on nurses' communication competence and self-efficacy: a randomized controlled trial.

Studies have shown that an underappreciation of the importance of person-centered communication and inappropriate communication training could result in unsatisfactory communication performance from nurses. There are a large number of studies about communication training for nurses, but not so many about communication training in early stages of nursing career. The purpose of this study is to compare the effect of a traditional course versus scenario-based simulation training on nurses' communication competency, communication self-efficacy, and communication performance in discharge planning Objective Structured Clinical Examination (OSCE). A randomized controlled trial was used with a pretest and two posttests. The experimental group underwent the scenario-based simulation course, whereas the control group received the traditional course. A convenience sample of 116 nurses with qualifications ranging from N0 level (novice nurses) to N2 level (competent nurses) in Taiwan's clinical nursing ladder system was recruited from a medical center in northern Taiwan. Analysis of covariance was used to determine between-subjects effects on communication competency and self-efficacy, whereas independent t test and Mann-Whitney U test were used to examine between-subjects effects on learner satisfaction and discharge planning communication performance. Paired t test was used to determine communication self-efficacy. In this study, the nurses and independent raters found scenario-based simulation training more effective than traditional communication course. However, standardized patients reported no significant difference in communication performance between the two groups of nurses. Despite that traditional classroom lectures and simulation-based communication training could both produce enhanced communication competency and self-efficacy among nurses, this study has established that the latter may be better than the former in terms of learner satisfaction and communication performance improvement. Therefore, introduction of simulation-based training to in-service nursing education could enhance nurses' communication performance in clinical practice.

Changes of Grain Yield and Nitrogen Use Efficiency of Maize Hybrids Released in Different Eras in Shaanxi Province

Identifying the changes of grain yield and nitrogen use traits will facilitate the development of new maize hybrids with high yield and nitrogen use efficiency. In this study, 12 typical maize hybrids released from 1981 to 2010 in Shaanxi Province were grown in the field under three N rates(0, 120, and 240 kg ha–1) from 2011 to 2012 in Shaanxi, Northwest China. Nitrogen use efficiency and agronomic traits of maize were investigated. The result indicates that grain yield of maize hybrids increased with the increase of nitrogen rates, and the modern maize hybrids(2000s) showed better grain yield than the old ones(1980s) at three nitrogen levels. The yield genetic gains were 46, 65, and 83 kg ha–1 per year at N0, N120, and N240 levels repeat. The modern hybrids showed better biomass and grain yield than the old ones, but there was no clear changing trend in stover yield between hybrids of different ears. Increments of grain yield were achieved mainly through increasing the kernel number per ear, 1000-kernel weight and biomass, and the coefficient of light extinction decreased with the time process of cultivar development from 1981 to 2010. Changes of plant structure would allow the modern maize hybrids to improve light capture resulting in better grain yield than those of the old ones. For nitrogen use point of view, irrespective of nitrogen treatments, nitrogen use efficiency(NUE) of hybrids released increased in responses of time. But nitrogen use efficiency decreased with increasing nitrogen application rates, and nitrogen use efficiency(NUE) was highly correlated with N uptake efficiency(NUpE, r = 0.75), and not with N physiological efficiency(NUtE, r = 0.42). Increased NUE positively correlated with improved N uptake efficiency(NUpE), due to the greater post-anthesis N accumulation. The results indicated that improvements of 1000-kernel weight, kernel number per ear and nitrogen uptake efficiency(NUpE) should be considered during breeding for high yield and high nitrogen use efficiency of maize under low nitrogen and water limited conditions.

Response of Corn and Redroot Pigweed to Nitrogen Fertilizer in Different Irrigation Regimes

The effect of irrigation regimes and N rates on corn (Zea mays L.) yield and redroot pigweed (Amaranthus retroflexus L.) growth in sandy soils is not completely understood. Therefore, field experiments were conducted in a semiarid region of Iran in 2010 and 2011 to determine the influence of N rates and irrigation regimes on corn and redroot pigweed leaf area index (LAI), dry matter and grain yield, N uptake, irrigation water productivity (IWP) and N leaching loss. The experiment was conducted using a randomized complete‐block design with a split‐factorial arrangement of treatments in four replicates. The main plots were subjected to either a low (L) or a full (F) irrigation regime. The subplots were arranged in a factorial scheme with four N rates (0, 150, 300, and 450 kg N ha−1) and two levels of redroot pigweed interference with corn (weed free, CW0; and weedy, CW1). The results indicated that the more N was applied, the higher were corn grain yield losses in both irrigation regimes due to weed interference. The difference in corn grain yield between CW0F and CW1F treatments was 400 and 1800 kg ha−1 at N0 and N450 levels, respectively. In contrast, the difference between CW0L and CW1L reached 300 and 800 kg grain ha−1 at N0 and N450 levels, respectively. Based on the information gained in this study, we do not recommend increasing inputs (water and N), especially in sandy soils, to diminish the redroot pigweed/corn competition.

The potential role of spineless safflower (Carthamus tinctorius L. var. inermis) as fodder crop in central Italy

The present study aimed at assessing how nitrogen (N) fertilization affects nutritional characteristics of spineless safflower grown under Mediterranean conditions and evaluating a 2-days wilting treatment on moisture reduction and pH before ensiling. Spineless safflower, sown in November 2008, was grown in 3 m x 18 m plot (45 plants m-2). A randomized complete block design (RCBD) one cultivar x four N-fertilization levels (N0=0 kg/ha, land allocation, N1=35 kg/ha, N2=70 kg/ha, N3=105 kg ha-1) (3 replicates each level) was adopted. At mowing (May 2009, before blooming) the crop biomass production was recorded. Wilted plant material for each plot was collected and pH was measured. Dried and ground samples (1 mm mesh) were analyzed for crude protein (CP), lipids (EE), crude fibre (CFom), neutral detergent fibre (aNDFom), acid detergent fibre (ADF), lignin (ADL) and ash (ASH) content. All data were analyzed by ANOVA and difference among means was assessed significant at P<0.05. Biomass production showed a nitrogen-dose relationship [from N0=1.80±0.29 to N3=2.71±0.20 t ha-1 dry matter (DM), P<0.01]. N-fertilization significantly affected the CP content, with the highest values (17.52±0.26% DM) observed for the N3 fertilization level. The other nutritional characteristics (EE: 1.36±0.23% DM; CFom: 41.70±3.65% DM; aNDFom: 44,6±2.71% DM; ASH: 12.74±0.74% DM) were not or only slightly affected (ADF: 34.15±2.14%; ADL: 9.53±2.35) (P<0.05) by the N-fertilization. After the 2-day wilting treatment, the highest pH (5.99±0.08) was found for N2 treatment, while the lowest one (5.85±0.06) was recorded for the N0 level (P<0.01). The wilting treatment gave a sufficient moisture reduction, allowing satisfactory preservation of safflower by ensiling. Spineless safflower shows an interesting potential to be grown for ruminants feeding purposes in Mediterranean area. N-fertilization plays an important role as far as productivity of safflower and its CP content are concerned. Further studies are in progress to fully characterize safflower as fresh and preserved forage resource for crop-livestock production systems in central Italy.

Identification and characterization of quantitative trait loci for grain yield and its components under different nitrogen fertilization levels in rice (Oryza sativa L.)

A set of rice (Oryza sativa L.) recombinant inbred lines from a cross between Zhenshan 97 (indica) and HR5 (indica) was planted for four different growing seasons in two locations at three nitrogen (N) fertilization levels (N300, 300 kg urea/ha; N150, 150 kg urea/ha; and N0, 0 kg urea/ha). Grain yield and its components were evaluated, including grain yield per plant (GYPP), panicle number per plant (PNPP), grain number per panicle (GNPP), filled grains per panicle (FGPP), spikelet fertility percentage (SFP) and 100-grain weight (HGW). Correlation and path analysis indicated that SFP had the greatest contribution to GYPP at the N300 and N150 levels, but FGPP contributed the most to GYPP at the N0 level. Quantitative trait loci (QTL) were mapped based on a mixed linear model; genetic components (main effects, epistatic effects and QTL-by-environment interactions) were estimated separately. Six to 15 QTL with main effects were detected for each trait except SFP. Clusters of main-effect QTL associated with PNPP, GNPP, SFP and HGW were observed in regions on chromosomes 1, 2, 3, 5, 7 and 10. The main-effect QTL (qGYPP-4b and qGNPP-12) were only detected at the N0 level and explained 10.9 and 10.2% of the total phenotypic variation, respectively. A total of 33 digenic interactions among grain yield and its components were also identified. The identification of genomic regions associated with yield and its components at different nitrogen levels will be useful in marker-assisted selection for improving the nitrogen use efficiency of rice.

82: Evaluation of a Semi-Automated Segmentation Method for Delineation of Organs at Risk and Lymph Node Target Volumes in Head and Neck Radiotherapy Planning

The clinical implementation of conformal radiotherapy and IMRT has substantially increased the demand for automated contouring tools. The contouring for head and neck (HN) treatment planning requires many hours of meticulous manual delineation on individual slices of CT data. The objective of this work is to develop and assess an automated method to efficiently and accurately delineate organs-at-risk and uninvolved (N0) lymph node regions in the head and neck. A model-based segmentation framework was developed that deforms a standard HN model to conform to the corresponding structures in individual CT data using a minimum of manual segmentation. Planning CT data of seven patients with small volume primary disease (T1-2) in the nasopharynx, oropharynx, or glottis and N0 levels I-V were retrospectively selected. These patients had normal organs-at-risk and preserved N0 lymph node anatomy to limit the degree of geometrical variability for an initial segmentation study. Manual contouring was carried out for external contour, brain, brainstem, spinal cord, parotids, mandible, clavicles, and N0 lymph node regions Ib-V (International Consensus Guidelines) for all patients. The Ib-V nodal contours were combined to form single right and left volumes. In addition, for model generation, the anatomically bounding structures of the nodal regions such as submandibular gland and hyoid were contoured in two cases. The model stored a multi-modal set of prior knowledge: typical shape of each structure represented by surface meshes, geometrical orientation of structures with respect to one another, and object-specific CT contrast characteristics as a function of location on the mesh surfaces. The model generated from the first case was applied to the remaining cases. The 2nd case was used for model generation to assess the accuracy of the segmentation method for the first case. After manual translation and rotation of the model to the CT anatomy of each case, the algorithm automatically deformed the model to adapt to corresponding boundaries in the image. The algorithm only required manual segmentation of the parotids for anatomical guidance. The segmentation accuracy of the node regions was assessed by compiling the distances between each point on the surface of the auto-segmentation and the closest point on the manual contours. The duration of the procedure was recorded. The average discrepancy between automated and manual segmentation was .24 ± .28 cm (SD) for left Ib-V, and .21 ± .23 cm (SD) for right Ib-V. The maximum error ranged from 1.9 cm (left level V) to 0.7 cm (right level III). On average, 75% (left) and 84% (right) of the nodal area surfaces were within .3 cm distance of the manual contours. The entire segmentation procedure (positioning and adaptation) was performed on average within 118 seconds ± 46 seconds (SD). A model-based segmentation method was developed and quantitatively evaluated for lymph node regions from CT images in the head and neck. Future work will increase the degree of automation, and expand the applicability of the model to include patients with normal variations in anatomy, accommodation of primary disease, and variable degree of nodal involvement as well as consistency and efficiency of output.

Assessment of Biomass, Productivity and Sustainability of Soybean Based Cropping Systems at Three Levels of Nitrogen in Deep Vertisols of Semi-Arid Tropical India

ABSTRACT In a 2-year field experiment (2001/02-2002/03) on deep Vertisols of Bhopal, India, the production potential, economic feasibility and nutrient balance of five cropping systems (soybean, sorghum and maize as sole crops, soybean + sorghum and soybean + maize as intercrops) each at 0%, 75% and 100% recommended dose of nitrogen (RDN) during rainy season were evaluated followed by growing wheat with RDN during post-rainy season. The results indicated that sole cropping of sorghum and maize recorded higher biomass yield than sole soybean and their intercrops. In contrast, the biomass yield of wheat during post rainy season was higher when the preceding crops were sole soybean or soybean + maize intercropping. At N0 level, intercropping of soybean + maize followed by wheat system was more productive and remunerative with a gain of 7.7 and 27.0 kg/ha of soil available P and K, respectively, but resulted in a net loss of 4.0 kg/ha of soil available N over a period of 2 years. This cropping system was less susceptible to runoff and soil erosion. At 75% and 100% recommended N levels, maize-wheat system was more productive and remunerative with a gain of 2.0 and 5.8 kg/ha of soil available N, 9.0 and 7.8 kg/ha of soil available P and 35.0 and 28.4 kg/ha of soil available K, respectively. However this cropping system resulted in higher runoff and soil loss. Adopting appropriate agronomic and soil conservation measures may correct the negative aspect of this system.

Carnivory and nitrogen supply affect the growth of the bladderwort Utricularia uliginosa

A glasshouse experiment was designed to determine whether the terrestrial bladderwort species Utricularia uliginosa Vahl. gained any growth advantage from carnivory at different levels of nitrogen enrichment of the substrate. Three organism treatments were used: a control, a protist-only treatment (Euglena spp.) and a protist + meiofauna treatment (Euglena spp. plus nematodes, copepods, ostracods, cladocerans and Acarina). The organism treatments were factorially combined with three nitrogen levels (N0, N1, N2). Populations of Euglena were successfully established in the substrate of pots in the protist, and meiofauna + protist treatments, and were found in the traps of plants growing in these treatments. Populations of the meiofauna from the inoculating cultures were successfully established in the meiofauna + protist treatment, and were trapped by plants in these treatments. A background contamination of the control and protist-only treatments by Acarina occurred over the course of the experiment; however, numbers of Acarina in these treatments were at least an order of magnitude lower than numbers of meiofauna in the meiofauna + protist treatment. Non-acarinid meiofauna were restricted solely to the meiofauna + protist treatment. Organism treatment interacted significantly with the nitrogen level of the substrate to affect growth of Utricularia. Plants trapping Euglena (+ Acarina) had significantly less dry weight than control plants at the N0 base level of nitrogen; this negative effect of trapping Euglena on plant growth disappeared at the two higher nitrogen levels. The dry weight of plants trapping the full range of meiofauna at the N0 level was comparable with control plants. Plants trapping the full range of meiofauna + Euglena at the N1 level had significantly more dry weight than plants trapping Euglena only, and the highest dry weight of any treatment; the benefit of trapping the full range of meiofauna + Euglena was non-significant at the N2 level. Dry weight of plants was not significantly affected by nitrogen in any organism treatment. These results suggest that carnivory was overcoming a nitrogen deficiency induced by Euglena at the N0 level, but was overcoming deficiencies of other nutrients at the N1 level.

Neural correletes of masked threshold

The detectability of tonal and noise signals was measured in the goldfish using classical respiratory conditioning at various levels of a continuous broadband noise masker, and as a function of signal duration. At threshold for an 800-Hz tone, the signal-to-noise ratio (E/N0 = 22 dB and is generally independent of noise level and signal duration. The response of single eighth nerve fibers of the goldfish was measured under identical acoustic conditions and at the same N0 levels used in the psychophysical studies. For E/N0 below 22 dB, phase-locking to the signal occurs, but spike rate is not different from that evoked by noise alone. At E/N0 = 22 dB, the coefficient of synchronization tends to equal 0.5, and spike rate begins to rise above that evoked by noise alone. For E/N0 above 22 dB, synchronization begins to saturate and log spike rate grows linearly with signal level in dB. This function reaches a maximum slope of a doubling of driven rate per 3 dB increase in signal level under optimum conditions. Near E/N0 = 22 dB, the number of spikes evoked by a tone burst signal is linearly related to signal energy. While we are not able to determine whether masked signal detection is based upon synchronization or spike rate criteria, it is clear that behavioral detection is not based on synchronization values below 0.5.

Effect of nitrogen and phosphorus levels on nutritive values of Sweet Peppers (Capsicum annum L.) fruits

The effect of different levels of nitrogen N0 (0), N1 (60), N2 (80) and N3 (100) kg/ha and phosphorus P0 (0), P1 (32), P2 (48) and P3 (64) kg/ha on the nutrient composition of sweet pepper fruits was investigated. Dry matter content was found to increase at N0 level at highest concentration of phosphorus and as well as at P0 level at highest concentration of nitrogen. At P2 concentration, at different levels of nitrogen, the ascorbic acid content was more as compared to that at other levels of phosphorus. Protein content was found to increase with increasing nitrogen doses and was also found to increase at maximum dose of nitrogen with increasing concentration of phosphorus. Capsaicin content was found to be more at P2 level at different doses of nitrogen. The uptake of phosphorus by the pepper fruit was found to increase at N0 and N2 levels. Maximum uptake of phosphorus and dry matter content was observed at N0P3 levels. Maximum protein, ascorbic acid and capsaicin contents were found at N3P2 level.