A New Active Contour Medical Image Segmentation Method Based on Fractional Varying-Order Differential

Image segmentation technology is dedicated to the segmentation of intensity inhomogeneous at present. In this paper, we propose a new method that incorporates fractional varying-order differential and local fitting energy to construct a new variational level set active contour model. The energy functions in this paper mainly include three parts: the local term, the regular term and the penalty term. The local term combined with fractional varying-order differential can obtain more details of the image. The regular term is used to regularize the image contour length. The penalty term is used to keep the evolution curve smooth. True positive (TP) rate, false positive (FP) rate, precision (P) rate, Jaccard similarity coefficient (JSC), and Dice similarity coefficient (DSC) are employed as the comparative measures for the segmentation results. Experimental results for both synthetic and real images show that our method has more accurate segmentation results than other models, and it is robust to intensity inhomogeneous or noises.

PHENOTYPIC AND GENETIC PARAMETERS ESTIMATED FOR FRESH CORN UNDER DIFFERENT NUTRIENT AVAILABILITY1

ABSTRACT The objective of this work was to estimate and compare phenotypic and genetic parameters after three cycles of intrapopulation recurrent selection for fresh corn grown under three nutrient availability conditions. Three experiments derived from the same population (MV-003) were conducted to assess the ability of progenies to absorb nutrients, one under adequate fertilization (control; MV-006), one under low nitrogen availability (N; MV-006N), and one under low phosphorus availability (P; MV-006P). The experiments were carried out in randomized blocks, with 64 half-sib progenies and three replications for each nutritional condition. Chlorophyll index, plant height, ear insertion, ear diameter, ear length, unhusked ear yield, and marketable husked ear were evaluated. The populations showed variability for the three nutrient availability conditions. The variability reduced after only three selection cycles; thus, evaluating a higher number of half-sib progenies, above 64, under low N and P availability is indicated. The rates used to identify the most efficient progenies in breeding programs should be close to the appropriate one, with a slow reduction after the selection cycles. The variability will be thus maintained, with a greater possibility of identifying more promising progenies. In addition, the frequency of favorable alleles increases more gradually and effectively. The N and P rate of 60 kg ha-1 is not indicated as a critical level for the initial phase of the program.

Fertilization management strategies for ‘Agata’ potato production

ABSTRACT Fluctuations in potato prices and invariably rising production costs need sustainable fertilization strategies. For this purpose, two experiments were conducted in the southwestern region of São Paulo state to evaluate fertilization management strategies for the ‘Agata’ potato cultivar. The treatments consisted of the producer’s standard fertilization (1700 kg ha-1 NPK 4-30-10 at planting + 100 kg ha-1 urea and 150 kg ha-1 KCl at hilling) and combinations of two P rates at planting (standard rate and half of the rate), as monoammonium phosphate (MAP) with two forms of KCl application (total rate in the post-planting phase or half of the rate in the post-planting phase and half at hilling). The application of half the P rate (255 kg ha-1 P2O5) as the MAP at planting and the transfer of K from planting to applications in the post-planting phase or in the post-planting phase and at hilling, despite having provided a lower leaf P concentration, maintained the total tuber yield with higher operational yield of planting fertilization. It also increased the yield of tubers with a diameter >4.5 cm under conditions of lower water availability in the vegetative stages of the crop and soil with medium availability of P and K. Such a fertilization strategy is valuable for cost reductions and possible environmental liabilities.

Optimizing the rate of phosphorus to enhance grain yield and quality in two Camelina sativa (L.) crantz accessions

Camelina sativa (L.) Crantz is an emerging oil seed crop and research information on its response to different levels of phosphorous (P) fertilizer is lacking. The two years study was performed to investigate the response of C. sativa to various rates of P fertilizer. The experiments were laid out in Randomized Complete Block Design (RCBD) with factorial arrangement having four replications. The P was applied in soil at the rate of 0, 30, 40 and 60 kg ha-1 to two C. sativa accessions namely Canadian and Australian. Soil applied phosphorus rates had significant effects on the growth, yield and quality of C. sativa and two accessions were varied to each other. Australian accession performed better in terms of quality traits and Canadian was superior in terms of seed yield. An increase in P rate improved growth, yield and quality and 60 kg P ha-1 resulted in maximal crop growth rate (6.79), seed yield (1239 kg ha-1), total P uptake (0.67%) and oil contents (39.8%). The regression model estimated that each increment in P rate increased the seed yield by 11.5 and 11.2 kg ha-1 in Canadian and Australian accessions, respectively. Conclusively, increases in P rates (0 to 60 kg ha-1) impart a positive impact on C. sativa accessions and 60 kg P ha-1 was most effective to achieve optimum yield and profitability.

Effect of P Application Rate and Rhizobium Inoculation on Nodulation, Growth, and Yield Performance of Chickpea (Cicer arietinum L.)

Chickpea (Cicer arietinum L.) is the world’s third most vital food legume after beans and peas in production level. Yet, its productivity in the last decade has been declined, and it has been contended that the usual native soil rhizobial populations are insufficient/ineffective in N2-fixation. Rhizobium inoculation of the seed may substitute costly N-fertilizers and provide a useful way of achieving sustainable production. Hence, to supply an adequate rhizobial population in the rhizosphere, seed inoculation of chickpea with an effective and importunate rhizobial strain is essential in soils having no/feeble bacterial existence and has revealed optimistic effect on nodule number and mass, growth, yield, and its attributes over uninoculated ones. Its effect has been influenced by N content and P-deficiency of soil, rhizobium strain, variety, T°, pH, salinity, and moisture stress. Phosphorus (P) demand is high in chickpeas, and P deficiency also has a negative effect on chickpea production success. Several research results revealed significant effects of P rate (30–200 kg P2O5 ha−1) on nodule number, mass, and rating plant−1; LAI, RGR, DM, plant height, and branches plant−1; pods and grains plant−1, grain and biomass yields, 100-grain weight, and HI compared to the control. P rates response has been affected by moisture level, pH, available P and N, and variety. Particularly, joint use of P rate and rhizobium inoculation on chickpea has been stated to improve nodulation, growth, and yield and soil fertility. Various studies on the integrated use of P rate and rhizobium inoculation under varying situations showed enhanced nodulation, growth, and yield over the P rate or rhizobium inoculation alone. This might be attributed to adequate P supply and improved utilization with the provision of suitable N2-fixing bacteria for enhanced nodulation and adequate N supply.

Examining Phosphorus Use Efficiency Across Different Lettuce (Lactuca sativa L.) Genotypes

Most agricultural soils worldwide present limited availability of phosphorus (P) and crops require supplemental application of P fertilizers. Due to the economic and environmental concerns derived from the use of P fertilizers, identifying and breeding P-efficient lettuce (Lactuca sativa L.) cultivars is imperative for the reduction of production costs and implementation of more sustainable practices. Phosphorus use efficiency (PUE) remains unexplored in lettuce. In this research, 66 lettuce genotypes of six morphological types were evaluated between standard recommended P rate (202 kg·ha–1 of P2O5) and half-P rate (101 kg·ha–1 of P2O5). Lettuce genotypes were tested in two field experiments conducted during the 2017-2018 and 2019-2020 growing seasons in the organic soils (Histosols) within the Everglades Agricultural Area of South Florida. Head weight, marketability, tissue P concentration, soil total-P concentration, and soil extractable P were measured. Genetic variation was detected for PUE within romaine, crisphead, butterhead, Latin, and loose leaf. Eight genotypes were found to produce similar or higher head weight and good marketability when grown in the half-P rate compared to the standard P rate. No correlations were detected between head weight and tissue P concentration, indicating possible variation in P uptake and utilization on the tested lettuce genotypes. A significant, positive correlation was observed for soil total-P and soil extractable P, indicating that the increase in total P concentration of Histosols resulted in higher availability of P to plants. Lettuce genetic variation for PUE may allow further development of P-efficient cultivars for conventional and alternative production systems. More comprehensive investigations must be conducted to elucidate the genetic mechanisms controlling PUE in lettuce.

Conjunctions as Cohesive Devices in Some Selected Animated Movies: A Discourse Analysis

Animated movies are one type of movies that are presented for children and they are classified according to their age. G- Rate movies, for example, are suitable for pre-school age, PG- Rate movies are for school age and P- Rate movies are for teenagers. These movies are created by computer and shown as a series of different movements of people, animals and objects. The use of conjunctions in children's movies is important and help children in connecting different units and clarifying the meaning of the text, and thus, they are considered as one of the important cohesive devices in making unity. The present study aims at finding out the types of conjunctions and investigating the most dominant conjuncts in four selected animated movies. These movies are from two different rates, G and PG movies. G- Rate movies include 'The Little Mermaid' and ' Princess'; and PG-Rate movies are' Moana' and 'Frozen'. Many studies, like, (Clark, 1973, Bloom, 1980, Vygotsky, 1962 and etc…) have observed that the use of connectives is an important point of developing children's cohesive skills and they use conjunctions, for example, and, because, and etc.…., before 6 years but after this age the semantic meaning and production of conjunctions are obvious (Joseph and etal. 1996: 160-161). According to these studies, the researcher hypothesizes that conjunctions are one of the important linguistic feature to be investigated and they are used more in PG-rate movies than in G- rate because this rate is presented for school-age and in this period children's language is developed and the use of conjunctions is more than in the period of pre-school. Furthermore, in this period children tend to connect ides and like to ask a lot of questions to get more information about different topics, but in pre-school age, children tend to use simple language and they focus on one idea. So, the use of conjunctions in G-rate movies will make the movie in somehow difficult. Therefore, literary works are crea

Soil Microbial Composition and phoD Gene Abundance Are Sensitive to Phosphorus Level in a Long-Term Wheat-Maize Crop System

Microbes associated with phosphorus (P) cycling are intrinsic to soil P transformation and availability for plant use but are also influenced by the application of P fertilizer. Nevertheless, the variability in soil P in the field means that integrative analyses of soil P cycling, microbial composition, and microbial functional genes related to P cycling remain very challenging. In the present study in the North China Plain, we subjected the bacterial and fungal communities to amplicon sequencing analysis and characterized the alkaline phosphatase gene (phoD) encoding bacterial alkaline phosphatase in a long-term field experiment (10 years) with six mineral P fertilization rates up to 200 kg P ha–1. Long-term P fertilization increased soil available P, inorganic P, and total P, while soil organic P increased until the applied P rate reached 25 kg ha–1 and then decreased. The fungal alpha-diversity decreased as P rate increased, while there were no significant effects on bacterial alpha-diversity. Community compositions of bacteria and fungi were significantly affected by P rates at order and family levels. The number of keystone taxa decreased from 10 to 3 OTUs under increasing P rates from 0 to 200 kg ha–1. The gene copy numbers of the biomarker of the alkaline phosphatase phoD was higher at moderate P rates (25 and 50 kg ha–1) than at low (0 and 12.5 kg ha–1) and high (100 and 200 kg ha–1) rates of P fertilization, and was positively correlated with soil organic P concentration. One of the keystone taxa named BacOTU3771 belonging to Xanthomonadales was positively correlated with potential functional genes encoding enzymes such as glycerophosphoryl diester phosphodiesterase, acid phosphatase and negatively correlated with guinoprotein glucose dehydrogenase. Altogether, the results show the systematic effect of P gradient fertilization on P forms, the microbial community structure, keystone taxa, and functional genes associated with P cycling and highlight the potential of moderate rates of P fertilization to maintain microbial community composition, specific taxa, and levels of functional genes to achieve and sustain soil health.

Mechanistic insight into oxygen atom transfer reactions by mononuclear manganese(iv)–oxo adducts

Rate enhancements in sulfoxidation reactions are often associated with a change in mechanism. Kinetic studies of sulfoxidation reactions by a series of MnIV–oxo complexes reveal large rate changes while retaining an oxygen-atom transfer mechanism.