Exploring Manifoldlike Causal Sets and their Dimensions

Causal Set Theory is an approach to quantum gravity that tries to replace the continuum spacetime structure of general relativity with the spacetime that has the property of discreteness and causality. From the standpoint of causal set theory, our spacetime is made up of discrete points that are causally related to one another. A causal set is said to be manifoldlike if it can be faithfully embedded in a Lorentzian manifold. In this thesis, some of the fundamental properties of causal sets are discussed. The first chapter is devoted to the historical background of quantum gravity with a discussion of some important approaches in brief. The second chapter revolves around the history of causal set theory and its definition in detail. The third chapter deals with the computation of faithfully embedded causal sets in flat and curved spacetime and chain length distributions in flat spacetime in detail. In the fourth chapter, dimension is calculated using Modified Myrheim–Meyer dimension Estimator and Midpoint Scaling Dimensional Estimator

Radiological, clinical and laboratory based studies in the pathogenesis of desmoid tumours in familial adenomatous polyposis

Around 10% of desmoid tumours (DT) in familial adenomatous polyposis (FAP) patients grow relentlessly, causing major morbidity and mortality. Radiological, clinical or cellular predictors of aggressive DT are yet to be identified. The work described in this dissertation aimed to identify such predictors by radiological studies, and to develop management guidelines and identify possible targets for therapy. Nine FAP patients with DT underwent 64 multi detector computed tomography (64-MDCT), 1.5 Telsa magnetic resonance imaging (1.5T MRI), Diffusion Tensor Imaging (DTI), Dynamic Contrast Enhanced MRI (DCE-MRI) and Fluorine-18 Flurodeoxyglucose Positron Emission Tomography (18F-FDG PET CT). Direct comparision between 1.5T MRI and 64-MDCT found that MRI was at least equivalent to MDCT in the assessment of DT. DTI was feasible and detected an anisotropic diffusion, which was less directional than in muscle. Metabolic (FDG PET) and vascular imaging (DCE-MRI) of DT demonstrated a spectrum of findings and found that DT were generally hypovascular and poorly glucose avid. A review of nine FAP patients with intra-abdominal desmoid (IAD) and air-fluid level (AFL) on cross sectional imaging found that either a direct communication or translocation of microorganism from bowel led to the development of AFL. Some of these patients could be treated successfully with antibiotics and/or a percutaneous drain; however, the majority ultimately required complex surgery. Full sequence APC mutation analysis performed in three primary DT cell lines detected ‘second hit’ somatic mutation in only one, confirming the establishment of a true DT cell line. A study of choline metabolism using choline kinase alpha (CHKA) as a marker for activation, however, failed to demonstrate up regulation of choline metabolism in desmoid tumour cells. Studies of the Wnt signalling pathways confirmed the activation of canonical Wnt signalling in DT. Interestingly Wnt11, a non-canonical Wnt, was also up regulated in DT.Open Acces

Farmers’ knowledge and adoption of improved mandarin orchard management practices in Syangja district, Nepal

Mandarin is one of the major fruit crops in the mid-hills of Nepal. Since improved farming practices appear to offer a significant chance to boost production and revenue, a study was conducted in Syangja, Nepal with the objective to assess farmers’ knowledge and adoption of improved mandarin orchard management practices and identify factors affecting their adoption. Primary data were collected by the use of pretested semi-structured questionnaire from randomly selected 97 respondents within the study area. Data were entered and analyzed using MS Excel, SPSS, and STATA, and the inferences were retrieved using the binary logistic regression model. Findings revealed that the respondents were familiar with most of the improved orchard management practices, however, there was variation in the scale of adoption of these practices. The majority (>90%) were found to practice pruning, FYM application, and weed control; however, there were relatively fewer adopters when it came to the use of Bordeaux paste (75.25%), chemical fertilizers (17.52%), mulching (57.74%), irrigation (44.33%), and soil testing and amendment (39.18%). The study showed that the adoption of Bordeaux paste and soil amendment differ significantly by gender (p=0.069 and p=0.041, respectively). Training has a positive impact on the use of Bordeaux paste (p=0.026), chemical fertilizers (p=0.075), and soil amendment practices (p=0.003). The usage of chemical fertilizers is more prevalent among people with formal education (p=0.075). Knowledge level also positively influences the adoption of mulching (p=0.014) and soil amendment practices (p=0.000). The number of trees is positively and significantly associated (p=0.008) with irrigation practice. It is recommended that expanding access to irrigation facilities and encouraging the use of the recommended amount of fertilizers, mulch, and Bordeaux paste must be prioritized in the study area

First-Principles Prediction of New 2D p-SiPN: A Wide Bandgap Semiconductor

Pentagonal two-dimensional ternary sheets are an emerging class of materials because of their novel characteristic and wide range of applications. In this work, we use first-principles density functional theory (DFT) calculations to identify a new pentagonal SiPN, p-SiPN, which is geometrically, thermodynamically, dynamically, and mechanically stable, and has promising experimental potential. The new p-SiPN shows an indirect bandgap semiconducting behavior that is highly tunable with applied equ-biaxial strain. It is mechanically isotropic, along the x-y in-plane direction, and is a soft material possessing high elasticity and ultimate strain. In addition, its exceptional anisotropic optical response with strong UV light absorbance, and small reflectivity and electron energy loss make it a potential material for optoelectronics and nanomechanics

Large Negative Poisson\u27s Ratio and Anisotropic Mechanics in New Penta-PBN Monolayer

The scarce negative Poisson\u27s ratio (NPR) in a two-dimensional (2D) material is an exceptional auxetic property that offers an opportunity to develop nanoscale futuristic multi-functional devices and has been drawing extensive research interest. Inspired by the buckled pentagonal iso-structures that often expose NPR, we employ state-of-the-art first-principles density functional theory calculations and analyses to predict a new 2D metallic ternary auxetic penta-phosphorus boron nitride (p-PBN) with a high value of NPR. The new p-PBN is stable structurally, mechanically, and dynamically and sustainable at room temperature, with experimental feasibility. The short and strong quasi sp3-hybridized B-N bond and unique bond variation and geometrical reconstruction with an applied strain allow p-PBN to inherit a high value of NPR (-0.236) along the (010) direction, the highest among any other ternary penta iso-structures reported to date. Despite having a small elastic strength, the highly asymmetric Young\u27s modulus and Poisson\u27s ratio along the (100) and (010) directions indicate large anisotropic mechanics, which are crucial for potential applications in nanomechanics and nanoauxetics

Influence of socio-economic attributes of farmers on the adoption of orchard management practices of mandarin in Myagdi district, Nepal

Mandarin is one of the major and highly commercialized fruit crops of Nepal. However, its productivity is widely varied throughout the country. The association of socio-economic characteristics of the farmers with the adoption of different orchard management practices and ultimately productivity is less known. Therefore, survey research was conducted in the Myagdi district to study the influence of socio-economic attributes on the adoption of different orchard management practices and their relation to the productivity of mandarin. A total sample size of 94 was selected by simple random sampling technique and interviewed with a pre-tested, semi-structured questionnaire. Data were entered and analyzed using MS Excel, Statistical Package for the Social Sciences (SPSS), and STATA, and the inferences were retrieved using the binary logistic regression model and multiple linear regression model. The study showed that the education level of the farmers has a positive influence on the adoption of mulching (p = 0.04) and pruning (p = 0.07). The secondary income source of the household has a positive impact on the adoption of chemical fertilizers (p = 0.08) and pruning (p = 0.03). Commercial mandarin farming in larger area has a positive influence on the adoption of Bordeaux mixture (p = 0.03) and insect management (p = 0.01). Extension services has great influence on the adoption of chemical fertilizers (p = 0.02), mulching (p = 0.03), Bordeaux mixture (p = 0.00) and insect management (p = 0.1). However, education level (p = 0.05), area under mandarin farm (p = 0.09), and extension services (p = 0.00) discourage the adoption of intercropping in the mandarin orchard. The productivity of mandarin orchards was significantly enhanced by FYM application, chemical fertilizers, irrigation, weeding, and Bordeaux application. This study shows that the farmers with better socio-economic conditions are more likely to adopt improved management practices in mandarin orchard which in turn enhance their productivity

Personal Assistant Robot

Since the boom in science and technology, humans have been trying to invent machines that could reduce their efforts in day to day activities. In this paper, we develop a personal assistant robot that could pick up objects and return it to the user. The robot is controlled using an android application in mobile phones. The robot can listen to user’s command and then respond in the best way possible. The user can command the robot to move to given location, capture images and pick objects. The robot is equipped with ultrasonic sensor and web camera that helps it to move to different location effectively. It is also equipped with sleds that play important role in object picking process. The robot uses a tiny YOLOv3 model which is rigorously trained on several images of the object. There are some possible improvements that can be achieved which could help this robot to be used in several other fields as well

Isolation of Glucose Fermenting Nitrogen Fixing Gene (nifH) Containing Endophytic Bacteria from Seed and Roots of Wheat (Triticum aestivation l.)

The present study was conducted to study the nifH gene containing endophytic bacterial frequency in wheat seed and roots obtained from the soil of Chitwan and Kaski. One hundred and four isolates were studied for the presence of the nifH gene. There was a diversity in isolate characters obtained from root sample Root (R), direct seed sample (ds), and plant sample (P). None of the isolates from any sources showed indole-producing ability. About 18 isolates (15% of the total) contained the nifH gene through amplification of the gene by universal primers PolF and PolR. About 6 isolates from seed sample ds and 12 isolates from root sample R contained nifH gene. None of the isolates from root sample P manifested the presence of the nifH gene. Among 18 nifH- containing isolates, only 6 isolates manifested presence of cel3 gene of 400 bp, whereas, 11 isolates showed cel3 gene of 200 bp. All nifH gene containing isolates were confirmed to be bacteria by PCR amplification of 16s rRNA gene by universal primer 27F and 1492R and visualization of agarose gel matrix with bp range of approximately 530 under UV ray. Further research scope exists to use these microbes as a bio fertilizer in plant growth promotion studies by inoculation