Exact and Heuristic Methods for the Weapon Target Assignment Problem

The Weapon Target Assignment (WTA) problem is a fundamental problem arising in defense-related applications of operations research. This problem consists of optimally assigning n weapons to m targets so that the total expected survival value of the targets after all the engagements is minimum. The WTA problem can be formulated as a nonlinear integer programming problem and is known to be NP-complete. There do not exist any exact methods for the WTA problem which can solve even small size problems (for example, with 20 weapons and 20 targets). Though several heuristic methods have been proposed to solve the WTA problem, due to the absence of exact methods, no estimates are available on the quality of solutions produced by such heuristics. In this paper, we suggest linear programming, integer programming, and network flow based lower bounding methods using which we obtain several branch and bound algorithms for the WTA problem. We also propose a network flow based construction heuristic and a very large-scale neighborhood (VLSN) search algorithm. We present computational results of our algorithms which indicate that we can solve moderately large size instances (up to 80 weapons and 80 targets) of the WTA problem optimally and obtain almost optimal solutions of fairly large instances (up to 200 weapons and 200 targets) within a few second

Issues and opportunities associated with SARS CoV-2 (COVID-19) virus detection in sewage

COVID-19 has emerged as pandemic challenge for the world. Novel information is emerging from the research and development. In this connection several reports are confirming presence of SARS CoV-2 in the sewage. This information has concern for the sanitary professionals involved in management of sewage and sludge of sewage treatment (biosolids). The same information also has opportunities to apply wastewater related epidemiology concept for rapid screening of a community impacted by COVID-19 and extent of its spread. The present article discusses issues and opportunity involved with the available information related to detection of RNA strains and whole virus in sewage

3D QSAR analysis on quinoxaline derivatives as anti-malarial using K-nearest neighbour molecular field analysis

727-731In the present article, k nearest neighbour molecular field analysis (kNN-MFA) method was used to develop a three dimensional quantitative structure activity relationship (3D-QSAR) model. In this study 37 derivatives of quinoxaline having antimalarial activity were used. Sphere exclusion (SE) algorithm was used to create the biological activity data set in to into training and test set. For model generation kNN-MFA method has coupled with stepwise, simulated annealing and genetic algorithm this method provides various models, in which the most significant model developed by stepwise backward-forward method with predictive internal q2=0.7589 and external predictivity (pred_r2 = 0.4752). In the presented model electrostatic descriptors play crucial role for activity. Electrostatic descriptor (E_137) indicates regions in which electron withdrawing groups are favourable and descriptor (E_939) represents electron rich or electron donating groups are advantageous in particular region. The counter map/ plot of this model further helps to understand the relationship of structural feature of derivative of quinoxaline and its biological activity this would be applied for designing of new potent antimalarial containing quinoxaline as lead

Critical Analysis of Information Sources and Channels Preferred by Rapeseed-Mustard Farmers

ABSTRACT An effective communication or information is pre-requisite for adoption of an innovation or a technology. The present study was conducted in 2003-04 to study the utilization and credibility pattern of information sources and channels by the rapeseed-mustard farmers in Rajasthan. The 350 rapeseed-mustard growers from five districts of Rajasthan were interviewed. The study reported that personal localite sources like neighbours, friends, progressive farmers and opinion leaders were playing important role in transfer of rapeseed-mustard technologies to the fellow farmers. These sources with high credibility were widely used by majority of the respondents. The most revealing finding of the study is that VLWs or Agriculture Supervisors had lost their credibility among the farmers while the input dealers and agents of commercial seed, fertilizers, plant protection, etc., played a critical role in information network of rapeseedmustard farmers, however their credibility is low. It was important to note that scientists and agriculture officers were perceived a much credible source of information by rapeseed-mustard farmers, however these sources were less accessible to the farmers. Further, the increasing literacy rate and easy accessibility of the mass media channels resulted in increased utilization of these media by the farmers. Key words : Information sources and channels; Utilization; Credibility; Adoption; Rapeseed-mustard is the important oilseed crop of India. Rajasthan occupying a prime position among the states and accounts for around 40 per cent of acreage and 38 per cent of total production of rapeseedmustard in India. A number of technical information or innovations for increasing rapeseed-mustard production and productivity have been generated by the research system. The farmers have adopted some of them but still there are many, which have not reached to the farmers. An important pre-requisite for the adoption and diffusion of an innovation within a social system is the effective communication of information relating to the innovation involved. In this context, the sources and channels of information utilized by farmers play an important role. Indian farmers have their own information networks where they continuously interact to get the information about agriculture and to get the solution of their problems. A farmer relies on a few information sources and rejects many others. Therefore, it is necessary to identify different sources and channels of agriculture information available to the rapeseed-mustard farmers and to locate the most utilized sources and channels so as to develop a suitable communication strategy. The utilization of sources and channels may vary from region to region and crop to crop. No study has been done to identify the information sources and channels utilized by rapeseed-mustard farmers in Rajasthan. Identification of these information sources and channels, their utilization pattern and their credibility perceived by the rapeseed-mustard farmers will be helpful for extension agencies and personnel engaged in transfer of technology programmes in selecting appropriate information sources and channels for effective and rapid transfer of new agriculture technologies. The present study was undertaken with the following objectives. 1. To study the utilization and credibility pattern of information sources and channels used by rapeseedmustard farmers. 2. To make the suggestions/recommendations for making information sources and channels more effective for rapid transfer of recommended agriculture technologies. METHODOLOGY The visitors advisory service was being provide

3D QSAR analysis on quinoxaline derivatives as anti-malarial using K-nearest neighbour molecular field analysis

In the present article, k nearest neighbour molecular field analysis (kNN-MFA) method was used to develop a three dimensional quantitative structure activity relationship (3D-QSAR) model. In this study 37 derivatives of quinoxaline having antimalarial activity were used. Sphere exclusion (SE) algorithm was used to create the biological activity data set in to into training and test set. For model generation kNN-MFA method has coupled with stepwise, simulated annealing and genetic algorithm this method provides various models, in which the most significant model developed by stepwise backward-forward method with predictive internal q2=0.7589 and external predictivity (pred_r2 = 0.4752). In the presented model electrostatic descriptors play crucial role for activity. Electrostatic descriptor (E_137) indicates regions in which electron withdrawing groups are favourable and descriptor (E_939) represents electron rich or electron donating groups are advantageous in particular region. The counter map/ plot of this model further helps to understand the relationship of structural feature of derivative of quinoxaline and its biological activity this would be applied for designing of new potent antimalarial containing quinoxaline as lead.

Cytokinin and abiotic stress tolerance -What has been accomplished and the way forward?

More than a half-century has passed since it was discovered that phytohormone cytokinin (CK) is essential to drive cytokinesis and proliferation in plant tissue culture. Thereafter, cytokinin has emerged as the primary regulator of the plant cell cycle and numerous developmental processes. Lately, a growing body of evidence suggests that cytokinin has a role in mitigating both abiotic and biotic stress. Cytokinin is essential to defend plants against excessive light exposure and a unique kind of abiotic stress generated by an altered photoperiod. Secondly, cytokinin also exhibits multi-stress resilience under changing environments. Furthermore, cytokinin homeostasis is also affected by several forms of stress. Therefore, the diverse roles of cytokinin in reaction to stress, as well as its interactions with other hormones, are discussed in detail. When it comes to agriculture, understanding the functioning processes of cytokinins under changing environmental conditions can assist in utilizing the phytohormone, to increase productivity. Through this review, we briefly describe the biological role of cytokinin in enhancing the performance of plants growth under abiotic challenges as well as the probable mechanisms underpinning cytokinin-induced stress tolerance. In addition, the article lays forth a strategy for using biotechnological tools to modify genes in the cytokinin pathway to engineer abiotic stress tolerance in plants. The information presented here will assist in better understanding the function of cytokinin in plants and their effective investigation in the cropping system

Intrinsic Vertebral Markers for Spinal Level Localization in Anterior Cervical Spine Surgery: A Preliminary Report

Study DesignProspective clinical study.PurposeTo observe the usefulness of anterior cervical osteophytes as intrinsic markers for spinal level localization (SLL) during sub-axial cervical spinal surgery via the anterior approach.Overview of LiteratureVarious landmarks, such as the mandibular angle, hyoid bone, thyroid cartilage, first cricoid ring, and C6 carotid tubercle, are used for gross cervical SLL; however, none are used during cervical spinal surgery via the anterior approach. We present our preliminary assessment of SLL over anterior vertebral surfaces (i.e., intrinsic markers) in 48 consecutive cases of anterior cervical spinal surgeries for the disc-osteophyte complex (DOC) in degenerative diseases and granulation or tumor tissue associated with infectious or neoplastic diseases, respectively, at an ill-equipped center.MethodsThis prospective study on patients undergoing anterior cervical surgery for various sub-axial cervical spinal pathologies aimed to evaluate the feasibility and accuracy of SLL via intraoperative palpation of disease-related morphological changes on anterior vertebral surfaces visible on preoperative midline sagittal T1/2-weighted magnetic resonance images.ResultsDuring a 3-year period, 48 patients (38 males,10 females; average age, 43.58 years) who underwent surgery via the anterior approach for various sub-axial cervical spinal pathologies, including degenerative disease (n= 42), tubercular infection (Pott's disease; n=3), traumatic prolapsed disc (n=2), and a metastatic lesion from thyroid carcinoma (n=1), comprised the study group. Intrinsic marker palpation yielded accurate SLL in 79% of patients (n=38). Among those with degenerative diseases (n=42), intrinsic marker palpation yielded accurate SLL in 76% of patients (n=32).ConclusionsIntrinsic marker palpation is an attractive potential adjunct for SLL during cervical spinal surgeries via the anterior approach in well-selected patients at ill-equipped centers (e.g., those found in developing countries). This technique may prove helpful when radiographic visualization is occasionally inadequate