366 research outputs found

    Optimal route planning of agricultural field operations using ant colony optimization

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    Farming operations efficiency is a crucial factor that determines the overall operational cost in agricultural production systems.  Improved efficiency can be achieved by implementing advanced planning methods for the execution of field operations dealing, especially with the routing and area coverage optimisation aspects. Recently, a new type of field area coverage patterns, the B-patterns, has been introduced.  B-patterns are the result of a combinatorial optimisation process that minimizes operational criterions such as, the operational time, non-working travelled distance, fuel consumption etc.  In this paper an algorithmic approach for the generation of B-patterns based on ant colony optimisation is presented.  Ant colony optimization metaheuristic was chosen for the solution of the graph optimisation problem inherent in the generation of B-patterns.  Experimental results on two selected fields were presented for the demonstration of the effectiveness of the proposed approach. Based on the results, it was shown that it is feasible to use ant colony optimization for the generation of optimal routes for field area coverage while tests made on the resulting routes indicated that they can be followed by any farm machine equipped with auto-steering and navigation systems

    Operations planning for agricultural harvesters using ant colony optimization

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    An approach based on ant colony optimization for the generation for optimal field coverage plans for the harvesting operations using the optimal track sequence principle B-patterns was presented. The case where the harvester unloads to a stationary facility located out of the field area, or in the field boundary, was examined. In this operation type there are capacity constraints to the load that a primary unit, or a harvester in this specific case, can carry and consequently, it is not able to complete the task of harvesting a field area and therefore it has to leave the field area, to unload, and return to continue the task one or more times. Results from comparing the optimal plans with conventional plans generated by operators show reductions in the in-field nonworking distance in the range of 19.3-42.1% while the savings in the total non-working distance were in the range of 18-43.8%. These savings provide a high potential for the implementation of the ant colony optimization approach for the case of harvesting operations that are not supported by transport carts for the out-of-the-field removal of the crops, a practice case that is normally followed in developing countries, due to lack of resources

    Hepatoprotective effect of the root extract of green tea against malathion-induced oxidative stress in rats

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    Introduction: Organophosphorus (OPs) pesticides such as malathion intoxication has been shown to generate oxidative stress due to the production of free radicals and alteration of the antioxidant defense system. The aim of this study was to evaluate the effects of extracts from green tea (GT) hydroalcoholic extract on liver function.Methods: Male Wistar rats were separated into 4 groups of 8 rats each. Group I (control), group II was given GT (10 mg/kg/day). Animals of groups III received only malathion, group IV was given GT+ malathion. Animals received malathion 150 mg/kg by gavage and GT 30 mg/kg for 1 week through intraperitoneal injection. Twenty-four hours after treatment, blood samples were collected. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) concentrations as well as biomarkers of oxidative stress such as lipid peroxidation (LPO), total antioxidant capacity (TAC) and total thiol groups (TTG) were measured.Results: A decrease in ALT and AST levels in GT group were observed compared with the ones in control group. Also, the results showed that malathion could increase liver toxicity in rats through reduction of ALT and AST. Conclusion: Amelioration of malathion toxicity through reduction of inflammation may suggest a prolonged therapeutic option against pesticides-induced hepatotoxicity

    The validity and reliability of autism behavior checklist in Iran

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    Objectives: The aim of this study was to evaluate the psychometric features of the Persian version of the Autism Behavior Checklist (ABC). Method: The International Quality of Life Assessment (IQOLA) approach was used to translate the English ABC into Persian. A total sample of 184 parents of children including 114 children with autism disorder (mean age =7.21, SD =1.65) and 70 typically developing children (mean age = 6.82, SD =1.75) completed the ABC. Internal consistency, test-retest reliability, concurrent and discriminant validity, and cut-off score were assessed. Results: The results of this study revealed that the Persian version of the ABC has an acceptable degree of internal consistency (.73). Test-retest comparisons using interclass correlation confirmed the instrument's time stability (.83). The instrument's concurrent validity with Gilliam Autism Rating Scale (GARS) was verified; the correlation between total scores was .94. In the discriminant validity, the autism group had significantly higher scores compared to the normal group. Receiver Operating Characteristic (ROC) analysis revealed that individuals with total scores below 25 are less likely to be in the autism group. Conclusion: The Persian version of the ABC can be used as an initial screening tool in clinical contexts

    Quantum teleportation with nonclassical correlated states in noninertial frames

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    Quantum teleportation is studied in noninertial frame, for fermionic case, when Alice and Bob share a general nonclassical correlated state. In noninertial frames two fidelities of teleportation are given. It is found that the average fidelity of teleportation from a separable and nonclassical correlated state is increasing with the amount of nonclassical correlation of the state. However, for any particular nonclassical correlated state, the fidelity of teleportation decreases by increasing the acceleration.Comment: 10 pages, 3 figures, expanded version to appear in Quantum Inf. Proces

    Evaluation of Non- linear Growth Curves Models for Native Slow-growing Khazak Chickens

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    Native poultry is a valuable genetic source with high resistance against diseases providing an important subject for breeding programs. The non-linear mathematical modeling of the growth pattern may partly explain the relationship between requirements and body weight to precise feeding that plays a vital role in the animal enterprises. A study was conducted to compare five non-linear models including Gompertz, Richards, Lopez, Logistic, and Von Bertalanffy describing the growth curve of Khazak native chickens. A total of 120 Khazak chickens (male and female) were individually weighed from 0 to 29 weeks under the same condition. The models were fitted on body weight data set and then evaluated by goodness-of-fit criteriaincluding root mean square error (RMSE), Bayesian information criterion (BIC), Akaike information criterion (AIC), and adjusted coefficient of determination (R2Adj). Based on goodness-of-fit criteria, Lopez model was the most suitable one for describing the growth curves in female and male chickens. The effect of sex was significantly important on curve parameters in all models (P< 0.05). The highest and lowest initial weight (W0) parameter was estimated by Logistic and Richards models, respectively, however, the other parameters of the growth curves were higher in Lopez model compared to others. Male chickens had higher values for age (ti), and weight (wi) at inflection point than females. Using an appropriate model to describe the growth curve in native Khazak chickens could increase the accuracy of selection for rapid growth at early stages of age

    Prevention of liver cancer by standardized extract of Melissa officinalis L. in a rat model of hepatocellular carcinoma: Its potential role as a chemopreventive agent

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    Introduction: Hepatocellular carcinoma (HCC) is a primary malignancy of the liver and the third most common cause of cancer-related death worldwide. Melissa officinalis L. (M. officinalis L.), known as lemon balm is a medicinal plant, which has a wide range of pharmacological properties. This study was aimed to assess the chemopreventive effect of aqueous extract of M. officinalis (AMO) against diethyl nitrosamine (DEN)-induced hepatocellular carcinoma (HCC) in rats. Methods and Results: The model of hepatocellular carcinoma was induced by a single intraperitoneal injection of DEN (200 mg/kg) as an initiator and after two weeks was followed by daily oral administration of 2-acetylaminofluorene (30 mg/kg) as a promoter for two weeks. Lemon balm-treated rats were pretreated with AMO intragastrically at three different doses two weeks prior to DEN injection. At the end of the experiment, the marked reduction of serum biomarkers of liver damage and cancer, including alfa-fetoprotein (AFP), gamma glutamyl transpeptidase (GGT), alanine transaminase (ALT), and aspartate transaminase (AST) were observed in AMO complemented rats compared to DEN-treated animals. Furthermore, the extract exhibited in vivo antioxidant activity by elevating GSH concentration and preventing lipid peroxidation in the liver tissues of HCC rats. The relative weight of liver was also reduced in lemon balm-treated rats as a prognostic marker in HCC. Conclusion: Our findings demonstrated that M. officinalis has a chemopreventive effect against HCC in rats and can be suggested as a potential agent for the prevention of primary liver cancer. &nbsp

    A low-dose chest CT protocol for the diagnosis of COVID-19 pneumonia: a prospective study

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    Purpose: The increasing trend of chest CT utilization during the COVID-19 pandemic necessitates novel protocols with reduced dose and maintained diagnostic accuracy. We aimed to investigate the diagnostic accuracy of 30-mAs chest CT protocol in comparison with a 150-mAs standard-dose routine protocol for imaging of COVID-19 pneumonia. Methods: Upon IRB approval, consecutive laboratory-confirmed positive COVID-19 patients aged 50 years or older who were referred for chest CT scan and had same-day normal CXR were invited to participate in this prospective study. First, a standard-dose chest CT scan (150 mAs) was performed. Only if typical COVID-19 pneumonia features were identified, then a low-dose CT (30 mAs) was done immediately. Diagnostic accuracy of low-dose and standard-dose CT in the detection of typical COVID-19 pneumonia features were compared. Results: Twenty patients with a mean age of 64.20 ± 13.8 were enrolled in the study. There was excellent intrareader agreement in detecting typical findings of COVID-19 pneumonia between low-dose and standard-dose (intraclass correlation coefficient ICC = 0.98–0.99, P values &lt; 0.001 all readers). The mean effective dose values in standard- and low-dose groups were 6.60 ± 1.47 and 1.80 ± 0.42 mSv, respectively. Also, absolute cancer risk per mean cumulative effective dose values obtained from the standard- and low-dose CT examinations were 2.71 × 10−4 and 0.74 × 10−4, respectively. Conclusions: According to our study, it was found that proposed low-dose CT chest protocol is reliable in detecting COVID-19 pneumonia in daily practice with significant reduction in radiation dose and estimated cancer risk. © 2020, American Society of Emergency Radiology

    An exactly solvable quantum-lattice model with a tunable degree of nonlocality

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    An array of N subsequent Laguerre polynomials is interpreted as an eigenvector of a non-Hermitian tridiagonal Hamiltonian HH with real spectrum or, better said, of an exactly solvable N-site-lattice cryptohermitian Hamiltonian whose spectrum is known as equal to the set of zeros of the N-th Laguerre polynomial. The two key problems (viz., the one of the ambiguity and the one of the closed-form construction of all of the eligible inner products which make HH Hermitian in the respective {\em ad hoc} Hilbert spaces) are discussed. Then, for illustration, the first four simplest, kk-parametric definitions of inner products with k=0,k=1,k=2k=0,k=1,k=2 and k=3k=3 are explicitly displayed. In mathematical terms these alternative inner products may be perceived as alternative Hermitian conjugations of the initial N-plet of Laguerre polynomials. In physical terms the parameter kk may be interpreted as a measure of the "smearing of the lattice coordinates" in the model.Comment: 35 p
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