27 research outputs found

    Benchmarking Permutation Flow Shop Problem: Adaptive and Enumerative Approaches Implementations via Novel Threading Techniques

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    A large number of real-world planning problems are combinatorial optimization problems which are easy to state and have a finite but usually very large number of feasible solutions. The minimum spanning tree problem and the shortest path problem are some which are solvable through polynomial algorithms. Even though there are other problems such as crew scheduling, vehicle routing, production planning, and hotel room operations which have no properties such as to solve the problem with polynomial algorithms. All these problems are NP-hard. The permutation flow shop problem is also NP-hard problem and they require high computation. These problems are solvable as in the form of the optimal and near-optimal solution. Some approach to get optimal are exhaustive search and branch and bound whereas near optimal are achieved annealing, Genetic algorithm, and other various methods. We here have used different approach exhaustive search, branch and bound and genetic algorithm. We optimize these algorithms to get performance in time as well as get the result closer to optimal. The exhaustive search and branch and bound gives all possible optimal solutions. We here have shown the comparative result of optimal calculation for 10 jobs with varying machine number up to 20. The genetic algorithm scales up and gives results to the instances with a larger number of jobs and machines

    A COMPARATIVE ANALYSIS OF VITAMIN-C CONCENTRATION IN COMMERCIAL FRUIT JUICES AND FRESH FRUITS OF NEPAL WITH EFFECT OF TEMPERATURE

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    Objective: It was aimed to determine the best storage temperature for fruits to achieve the highest quality of vitamin-C and to compare vitamin C concentration between commercial fruits juices and fresh fruit juices in by using Spectrophotometry and Titrimetric method Methods: Titration involved the redox reaction between iodine and vitamin C. As the iodine was added during the titration, the ascorbic acid was oxidized to dehydroascorbic acid, while the iodine was reduced to iodide ions. The Spectrophotometric method involved the coupling reaction of 2,4 dinitrophenylhydrazine (DNPH) dye with Vitamin C. The samples were analyzed using UV-Vis-Spectrophotometer at 521 nm. Results: Titrimetric and spectroscopic methods were performed for fresh and marketed fruits comprising of apple, grapes, lemon, orange. The maximum amount was found in lemon and orange whereas apple and grapes contained lesser amount of Vitamin C. The stability of marketed fruit juices made up of apple, grapes, lemon, orange were analyzed by storing them on the freeze at 0 °C and 10 °C and on the hot air oven at 20 °C, 30 °C, 40 °C, 50 °C for 72 h and estimated by both Titrimetric and Spectroscopy method. UV-Spectroscopy method showed that, at freezing condition up to 10 °C temperature, degradation was too low but when the temperature reached 50 °C the extent of degradation was more, showing 24.56% apple juice, 10.89% orange juice,12.70% grapes juice and 50% orange juice were degraded in 100 ml sample. Similar results were observed by analysing the samples with titration technique. Conclusion: A new analytical method was developed to address the content of vitamin C in fruits consumed in the local market of Nepal along with the best possible storage of fruit juice to yield the maximum amount of nutrients

    EVALUATION OF IMMUNOMODULATORY ACTIVITY OF PETROLEUM ETHER EXTRACT OF SEEDS OF PITHECELLOBIUM DULCE IN WISTAR RATS

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    Objective: The present study was planned to assess the immunomodulatory action of petroleum ether extracts of seeds of Pithecellobium dulce (PEPD) in experimental models of immunity.Methods: Metronidazole, pyrogallol and ethanol models were used for suppression of the immune system in Wistar rats. Humoral immunity was analyzed by haemmagglutination assay, whereas, cellular immunity was carried out by paw edema and carbon clearance assay. PEPD (400 mg/kg, p. o.) was selected by acute toxicity study. Levamisole (50 mg/kg, p. o.) was used as standard.Results: Metronidazole, pyrogallol and ethanol significantly decreased the humoral and cellular immunity, whereas, PEPD and levamisole significantly increased the circulating antibody titer in the indirect haemagglunation test. PEPD and levamisole also produced significant increases in paw edema and increase in the phagocytic index in the carbon clearance assay. Animals treated with metronidazole, pyrogallol and ethanol decreased in peripheral blood RBCs and monocytes whereas, PEPD and levamisole treated groups significantly increased in peripheral blood RBCs and monocytes.Conclusion: Our data showed that PEPD possesses potential for augmenting immune activity by cellular and humoral mediated mechanisms and also significantly restores the biochemical and histopathological parameters. The present study concluded that PEPD may have therapeutic and prophylactic value as immunostimulants.Â

    Germplasm rescue and rebuilding local seed systems in red zone areas

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    Native agrobiodiversity become endangered and even lost due to natural disasters in red zone area such as earthquake that hit Nepal on April and May 2015. Endangered agricultural genetic resources should be rescued and revival of disrupted local seed system was essential for sustainable and productive agriculture in earthquake affected areas. The objectives of this paper are to document methods employed to rescue germplasm and rebuild local seed systems in earthquake affected areas to restore lost crop diversity and strengthen local seed systems. Among 14 severely hit districts by April 2015 earthquake in Nepal, 10 districts were selected for germplasm rescue and rebuilding local seed system. We surveyed households and sensitized relevant stakeholders. Earthquake affected areas were declared as red zones and status of crop landraces were assessed through survey, five cell analysis and focus group discussion. Three germplasm rescue techniques, namely direct rescue, diversity fair and indirect rescue were applied. Local seed systems were rebuilt through diversity fair, diversity block, seed exchange, repatriation and diversity kits. Collected accessions were characterized, multiplied and conserved in National Genebank and community seed banks. About 5-10% of total local crop diversity (based on the landraces) were lost due to earthquake in these districts. A total of 921 accessions of 61 crops along with 284 rare and endangered crop landraces were collected and rescued from 35 VDCs of 10 severely earthquake affected districts. Climate analogue sites and climate smart germplasm were identified for some of earthquake affected areas, and five landraces of four crops were repatriated. Participatory seed exchange, diversity fairs and 200 diversity kits (containing 3 to 5 varieties) were employed to revive the local seed systems. Farmers’ preferred landraces were conserved in Community Seed Bank in Lamjung and Dolakha and all collections were conserved in Naional Genebank, Khumaltar, Nepal. The study concludes that multiple approaches and tools are necessary for germplasm rescue and rebuilding local seed systems from red zone area &nbsp

    Analysis of cardiac autonomic modulation in normotensive obese and eutrophic adults of Nepal

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    Background: Obese people have a higher prevalence of cardiovascular disease, though unknown mechanism, supposed to be due to autonomic dysfunction which is still in controversy. This study aimed to assess and compare heart rate variability (HRV) between normotensive obese and adults.Methods: The study was conducted on 30 normotensive obese adults (mean age 32.07±7.25 years) with BMI>30 and 29 age- and sex-matched normal weight controls (mean age 30.48±8.01 years) with BMI: 18-24 Kg/m2. Short-term HRV variables were assessed using standard protocol. The data were compared between the groups using Mann Whitney ‘U’ test.Results: In obese group, there was significant increase in the mean heart rate [79.17±8.80 Vs 71.48±8.41 beats/min, p=0.001], systolic blood pressure [121.20±9.89 Vs 113.24±11.07, mmHg, p=0.004] and diastolic blood pressure [84.97±7.87 Vs 74.83±10.31 mmHg, p=0.000]. The HRV parasympathetic indicators were less [RMSSD {28.75(16.72-38.35) Vs 41.55(30.6-56.75) ms, p=0.018}, NN50 {15.5(2-39) Vs 83.5(32.75-116.25), p=0.010}], and sympathetic indicator LF/HF ratio [1.2(0.65-2.20) Vs 0.79(0.5-1.02), p=0.004] was more in obese group.Conclusions: Obese persons have increased sympathetic activity with a reduction in parasympathetic (vagal) tone indicating poor autonomic cardiac rhythm control. Moreover, the altered autonomic activity could be the reason for increased mean heart rate and blood pressures in normotensive obese persons

    Isolation and Characterization of Klebsiella Phages for Phage Therapy

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    Introduction: Klebsiella is a clinically important pathogen causing a variety of antimicrobial resistant infections in both community and nosocomial settings, particularly pneumonia, urinary tract infection, and sepsis. Bacteriophage (phage) therapy is being considered a primary option for the treatment of drug-resistant infections of these types. Methods: We report the successful isolation and characterization of 30 novel, genetically diverse Klebsiella phages. Results: The isolated phages span six different phage families and nine genera, representing both lysogenic and lytic lifestyles. Individual Klebsiella phage isolates infected up to 11 of the 18 Klebsiella capsule types tested, and all 18 capsule-types were infected by at least one of the phages. Conclusions: Of the Klebsiella-infecting phages presented in this study, the lytic phages are most suitable for phage therapy, based on their broad host range, high virulence, short lysis period and given that they encode no known toxin or antimicrobial resistance genes. Phage isolates belonging to the Sugarlandvirus and Slopekvirus genera were deemed most suitable for phage therapy based on our characterization. Importantly, when applied alone, none of the characterized phages were able to suppress the growth of Klebsiella for more than 12 h, likely due to the inherent ease of Klebsiella to generate spontaneous phage-resistant mutants. This indicates that for successful phage therapy, a cocktail of multiple phages would be necessary to treat Klebsiella infections.Peer reviewe

    Rice yield gaps and nitrogen-use efficiency in the Northwestern Indo-Gangetic Plains of India: Evidence based insights from heterogeneous farmers’ practices

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    A large database of individual farmer field data (n = 4,107) for rice production in the Northwestern Indo-Gangetic Plains of India was used to decompose rice yield gaps and to investigate the scope to reduce nitrogen (N) inputs without compromising yields. Stochastic frontier analysis was used to disentangle efficiency and resource yield gaps, whereas data on rice yield potential in the region were retrieved from the Global Yield Gap Atlas to estimate the technology yield gap. Rice yield gaps were small (ca. 2.7 t ha−1, or 20% of potential yield, Yp) and mostly attributed to the technology yield gap (ca. 1.8 t ha−1, or ca. 15% of Yp). Efficiency and resource yield gaps were negligible (less than 5% of Yp in most districts). Small yield gaps were associated with high input use, particularly irrigation water and N, for which small yield responses were observed. N partial factor productivity (PFP-N) was 45–50 kg grain kg−1 N for fields with efficient N management and approximately 20% lower for the fields with inefficient N management. Improving PFP-N appears to be best achieved through better matching of N rates to the variety types cultivated and by adjusting the amount of urea applied in the 3rd split in correspondance with the amount of diammonium-phosphate applied earlier in the season. Future studies should assess the potential to reduce irrigation water without compromising rice yield and to broaden the assessment presented here to other indicators and at the cropping systems level

    Interpretable machine learning methods to explain on-farm yield variability of high productivity wheat in Northwest India

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    The increasing availability of complex, geo-referenced on-farm data demands analytical frameworks that can guide crop management recommendations. Recent developments in interpretable machine learning techniques offer opportunities to use these methods in agronomic studies. Our objectives were two-fold: (1) to assess the performance of different machine learning methods to explain on-farm wheat yield variability in the Northwestern Indo-Gangetic Plains of India, and (2) to identify the most important drivers and interactions explaining wheat yield variability. A suite of fine-tuned machine learning models (ridge and lasso regression, classification and regression trees, k-nearest neighbor, support vector machines, gradient boosting, extreme gradient boosting, and random forest) were statistically compared using the R2, root mean square error (RMSE), and mean absolute error (MAE). The best performing model was again fine-tuned using a grid search approach for the bias-variance trade-off. Three post-hoc model agnostic techniques were used to interpret the best performing model: variable importance (a variable was considered “important” if shuffling its values increased or decreased the model error considerably), interaction strength (based on Friedman’s H-statistic), and two-way interaction (i.e., how much of the total variability in wheat yield was explained by a particular two-way interaction). Model outputs were compared against empirical data to contextualize results and provide a blueprint for future analysis in other production systems. Tree-based and decision boundary-based methods outperformed regression-based methods in explaining wheat yield variability. Random forest was the best performing method in terms of goodness-of-fit and model precision and accuracy with RMSE, MAE, and R2 ranging between 367 and 470 kg ha−1, 276–345 kg ha−1, and 0.44–0.63, respectively. Random forest was then used for selection of important variables and interactions. The most important management variables explaining wheat yield variability were nitrogen application rate and crop residue management, whereas the average of monthly cumulative solar radiation during February and March (coinciding with reproductive phase of wheat) was the most important biophysical variable. The effect size of these variables on wheat yield ranged between 227 kg ha−1 for nitrogen application rate to 372 kg ha−1 for cumulative solar radiation during February and March. The effect of important interactions on wheat yield was detected in the data namely the interaction between crop residue management and disease management and, nitrogen application rate and seeding rate. For instance, farmers’ fields with moderate disease incidence yielded 750 kg ha−1 less when crop residues were removed than when crop residues were retained. Similarly, wheat yield response to residue retention was higher under low seed and N application rates. As an inductive research approach, the appropriate application of interpretable machine learning methods can be used to extract agronomically actionable information from large-scale farmer field data

    The role of serotonin in synaptic plasticity: detailed characterisation of the effect of serotonin on long-term potentiation across the hippocampus

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    Serotonin (5HT) is one of the chief modulators of synaptic transmission in the brain. As such, 5HT has been suggested to be capable of modulating neuronal plasticity in the hippocampus, thereby regulating the processes of learning and memory. In this thesis, I extend the investigation of the role of broader 5HT signalling as well as the 5HT1A receptor signalling on the CA3—CA1 synaptic plasticity in the hippocampus. A systematic review and meta-analysis is performed that provides a comprehensive overview of the reported effects of 5HT signalling on LTP at the CA3—CA1 synapse. The systematic review of the existing literature shows that, overall, an increase in hippocampal 5HT levels can suppress CA3—CA1 LTP but a reduction in 5HT signalling appears to have little effect on LTP. This indicates that 5HT may not be essential for LTP induction and maintenance but that enhanced 5HT signalling can interfere with its expression. The systematic review, however, also revealed some contradictions in the reported effects of 5HT on CA3—CA1 LTP. Interestingly, while most existing reports of CA3—CA1 LTP treat the hippocampus as a homogenous structure, it has been suggested that the dorsal hippocampus is primarily involved in cognitive functions, while the ventral hippocampal functions have been related to stress, emotion and affect. In light of such findings, the effects of 5HT signalling on CA3—CA1 synaptic transmission and plasticity were investigated by measuring local field potential from mouse hippocampal slices using a multielectrode array (MEA). The effects of exogenous 5HT and a 5HT1A receptor agonist, NLX101, on basal transmission and LTP induction at the CA3—CA1 synapse were examined at different CA1 layers in slices taken from the dorsal or the ventral hippocampus. The presented data provides evidence, for the first time, that 5HT suppresses basal signalling in ventral layers stratum pyramidale (SP) stratum radiatum (SR) and stratum lacunosum-moleculare (SLM), but not in the dorsal layers. In contrast, the 5HT1A receptor selective agonist, NLX101, reduced basal transmission in layers SR and SLM, but the reduction was no longer statistically significant when sorted into dorsal or ventral slices. Nevertheless, following a high frequency stimulation (HFS), while 5HT was only able to suppress LTP in the dorsal layer SLM, the selective activation of the 5HT1A receptor suppressed LTP in all layers of the dorsal CA1. No significant change was observed in the ventral slices following an HFS in either drug group. The role of the serotonergic system on basal transmission and LTP induction appear to, primarily, involve postsynaptic mechanisms as paired pulse facilitation at the CA3—CA1 synapse remained unaffected by 5HT or NLX101. Finally, immunohistochemistry protocol was optimised with the aim of investigating the 5HT1A receptor expression in different areas of the hippocampus. The goal, guided by the principles of the 3Rs, was to use the same slices used for electrophysiological recordings so as to directly correlate the receptor expression study with the LTP study. Different protocols have been explored whereby the fixation, permeabilisation and antibody incubation steps were reviewed. We found that PFA fixation for 2 hours at 4°C, Triton X-100 at 1% w/w and primary and secondary antibody incubation for 2 nights each improved staining. Although there is scope for further optimisation such as antigen retrieval, the revised protocol showed that the 5HT1A receptors are expressed mostly in the pyramidal cell soma. The findings from this thesis suggest that while 5HT, in general, suppresses hippocampal LTP, different hippocampal sub-regions have different sensitivity to 5HT, and some, but not all, of the effects are mimicked by 5HT1A receptors. Such differential effects on LTP expression also provides support to the functional difference that is associated with the dorsoventral axis of the hippocampus.</p
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