Discreteness Of Curved Space-Time From GUP

Diverse theories of Quantum Gravity expect modification of the Heisenberg Uncertainty Principle near the Planck scale to a so-called Generalized Uncertainty Principle.It was shown by some authors that the Generalized uncertainty principle gives rise to corrections to Schrodinger,Klien-Gordon and Dirac equations.By solving the Generalized uncertainty principle corrected equations,the authors arrived at quantization not only of energy but also of box length,area and volume. We extend the above result to the case of curved Space-Time(Schwarzschild metric). We showed that we arrived at the Quantization of Space by solving Dirac equation with Generalized uncertainty principle in this metric.Comment: 7 page

The Impact of Perceived Leadership Styles on Hotel Employee Job Engagement

Engaged employees have a positive impact on organizational outcomes. In fact, employees who are highly committed to their jobs tend to perform better, and such employees are less likely to quit. Leaders in the workplace have the potential to influence employee work engagement. Different leadership styles might drive employee engagement to different extents. The purposes of this study are twofold: to identify the leadership styles and drivers that lead to engaged employees, and to contribute to the literature of employee engagement in the context of hospitality and tourism. This study used a quantitative method, specifically survey that was distributed to the United States hotel employees through Amazon M-Turk. The survey measures employee level of engagement using UWES and leadership styles using MLQ in addition to 18 drivers of engagement and 10 demographic questions. This study found that ‘fairness’ was evaluated as the most valuable driver to make employees feel engaged at work. The findings of this study showed that there is significant relationship between transformational and transactional leadership behavior and employee engagement whilst significant negative correlation was found between the perceived passive/avoidant leadership and employee engagement. Discussion, implications, limitations, and future research are presented

Dynamic routing optimization using traffic prediction

In this dissertation, a new efficient routing maintenance algorithm, called Predicting of Future Load-based Routing (PFLR), is introduced for optimizing the routing performance in IP-based networks. The main idea of PFLR algorithm is combing the predicted link load with the current link load with an effective method to optimize the link weights and so reduce the network congestions. Another research objective is introducing a new efficient Traffic Engineering (TE) algorithm, called Prediction-based Decentralized Routing (PDR) algorithm, which is fully decentralized and self-organized approach

Prediction-based Decentralized Routing Algorithm

We introduce a new efficient routing algorithm called Prediction-based Decentralized Routing algorithm (PDR), which is based on the Ant Colony Optimization (ACO) meta-heuristics. In our approach, an ant uses a combination of the link state information and the predicted link load instead of the ant's trip time to determine the amount of pheromone to deposit. A Feed Forward Neural Network (FFNN) is used to build adaptive traffic predictors which capture the actual traffic behaviour. We study two performance parameters: the rejection ratio and the percentage of accepted bandwidth under two different network load conditions. We show that our algorithm reduces the rejection ratio of requests and achieves a higher throughput when compared to Shortest Path First and Widest Shortest Path algorithms

Perceptions of physicians in Saudi Arabia on the use of international clinical guidelines for managing primary insomnia

Introduction While there are no national clinical guidelines for managing primary insomnia in Saudi Arabia, there are also no published studies of physicians’ perceptions of and attitudes towards using international guidelines. The objective of this study was to explore the knowledge, perceptions, and attitudes of physicians practising in Saudi Arabia about using international guidelines for managing insomnia. Methods A qualitative study using in-depth, face-to-face, and semi-structured interviews with 15 physicians held in July 2017 at a tertiary care hospital in Jazan, the distal south-western province in Saudi Arabia. Interviews were audio-recorded, transcribed verbatim, coded using the qualitative software NVivo11 and analysed thematically. Data saturation was assumed as no new understandings of the broad thematic issues were produced by the last three interviews. Results Themes identified were: Knowledge, Resistance, Barriers and Facilitators. Participants acknowledged their lack of awareness of available guidelines and their lack of training and education about Cognitive Behavioural Therapy for Insomnia (CBT-I). They highlighted a lack of education for patients about insomnia and its treatment. Beliefs about dependence on hypnotics and the inappropriateness of international guidelines for Saudi Arabia inclined many to resist using them. Inability to document diagnosis and consultations due to limited time and lack of suitable electronic systems, lack of suitably trained practitioners for referral for CBT-I, and lack of accountability for practice were identified as key barriers to following international guidelines. Development of national guidelines was the most important facilitator suggested by participants. Conclusions The health authorities in the government of the Kingdom of Saudi Arabia (KSA) should improve general public awareness about sleep disorders and provide focused training for specialists and technologists. Above all, KSA needs its own nationwide guidelines for treating sleep-disorders based on evidence-based clinical trials, consistent with its history, culture, socioeconomic conditions and traditions

Coherent control of polarized neutron interferometry

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 171-179).In this thesis, we describe two sets of experiments using a single crystal neutron interferometer. First, we explore applications of quantum information processing (QIP) to magnetic materials characterization using polarized neutron interferometry (NI). We describe a split path spin-based interferometer geometry that uses the Bragg interferometer to separate two paths where spin states are independently manipulated. The final measurement is made on the spin degree of freedom, so we observe spin-based contrast without a need for coherence in the path degree of freedom. This is difficult to achieve in a spin-echo interferometer because the two paths overlap, with only a time delay of one relative to the other. Second, we present a design of a novel spin rotator design meeting the stringent space and temperature constraints of NI experiments. These passive devices use remnant magnetization FeCoV thin films and can be tuned to achieve arbitrary rotation of an incident neutron with known magnetization. Polarized neutron reflectometry measurements are reported for FeCoV monolayer films at thicknesses of 0.5 [mu]m and 5.3 [mu]m to characterize the depth-dependent vector magnetization in the films. Stray field near such films is characterized to determine the effect on the neighboring neutron beam path. Contrast degradation due to the rotators is also discussed. Results for a prototype set of film rotators are presented showing a spin nutation > 90° from incident orientation. An architecture is presented for which any nutation angle can be achieved by tuning the separation of two composite film structures. We also propose an experimental implementation of the deterministic quantum computation with one pure qubit (DQC1) model of quantum computation in NI. This circuit generates no entanglement, yet no efficient classical simulation is known or thought to exist. We present calculations showing a nonzero quantum discord in this implementation, as a means of quantifying other nonclassical correlations in addition to entanglement. All experiments were conducted at the Neutron Interferometer and Optics Facility at the National Institute of Standards and Technology (NIST).by Mohamed Osama Abutaleb.Ph.D

An investigation of metastatic colorectal cancer

Colorectal cancer (CRC) is the third most common cancer worldwide and the fourth most common cause of death. This complex disease process starts in the colon or rectum, as a non-cancerous polyp which can become malignant over time. In the later stages of CRC, tumour cells become detached from the primary tumour, migrate and enter the blood or lymphatic vessels and ultimately form a secondary tumour at another site (distant metastasis). CRC metastasis may also arise from residual tumour cells that persist after treatment. Identifying biomarkers for potentially metastatic disease or residual disease may provide novel tools for early detection and therapy monitoring patients prior to metastasis and tumour recurrence. Genetic and epigenetic changes are required during every step in metastatic spread and these may have use as biomarkers as well as providing information about the mechanisms behind these changes. In addition, tumour cells release cellular contents into the bloodstream as a consequence of cell death during the metastatic process. These circulating free (cf) contents have potential to be cancer biomarkers for treatment monitoring and residual diseases detection. This thesis investigated the molecular events associated with metastatic CRCs in order to improve diagnosis and prognosis in this disease. DNA was extracted from 82 cases of formalin-fixed paraffin-embedded (FFPE) human CRCs. Mutation and methylation analysis was performed by QMC-PCR followed by high resolution melting (HRM) analysis. Using statistical methods, we analysed the association between the targeted mutations and lymph node involvement, local recurrence, and distant metastasis. The findings showed significant association of KRAS, PIK3CA, PTEN, SMAD4 mutations and P16 promoter methylation with lymph node involvement, advanced disease and local/metastatic recurrences. The study also confirmed that CRCs with microsatellite instability (MSI) were significantly associated with mutant BRAF. MSI occurs in sporadic tumours and tumours arising in Lynch Syndrome and BRAF is commonly found in sporadic tumours but almost never in Lynch Syndrome tumours. However not all sporadic tumours with MSI have mutation in BRAF and therefore a new assay was developed to discriminate sporadic tumours with MSI from tumours arising due to Lynch Syndrome. In order to develop tests to test for residual disease, blood samples of 25 CRC patients were collected pre-operation and daily post-operation (until discharge) and plasma was extracted for the analysis of cfDNA/ctmiRNA following operation. The matched primary tumours were also collected. A protocol for COLD-HRM (a combination of COLD-PCR and HRM designed for detection of low frequency of mutant alleles) was optimized to screen for KRAS and BRAF mutation. This protocol was subsequently used to screen cfDNA for mutations. ctmiRNA expression was quantified by Q-PCR. Findings in this study showed that patients can be divided into a group which either loses or retains mutant cfDNA/ctmiRNA following operation. Detection of mutations in cfDNA is a good means of non-invasive screening for CRC and may provide a novel method of assessing surgical clearance and testing for recurrence. The activation of GNAS1 by mutation leads to several biological possibly metastasis promoting events including cell proliferation, survival and motility. GNAS1 was found to be mutated in CRCs and therefore investigated for its activity in CRC cell lines. GNAS1 was knocked-down in two CRC cell lines (RKO, and SW620). Gene knockdown was undertaken by transfecting small interfering RNAs into the cells and this was followed by an evaluation of cell proliferation and motility. The findings of this study revealed that inhibition of GNAS1 expression does not show any effects on cell proliferation or migration in the CRC cell lines, RKO and SW620. In conclusion, this study identified specific targets, such as KRAS, PIK3CA, PTEN, SMAD4 mutations and P16 promoter methylation, in correlation with lymph node involvement, advance stage CRCs and local/distant recurrences. Further analysis and investigation for their functional role in CRC progression is required to further identify their exact impact on CRC cell proliferation and motility. This study also confirmed that cfDNA/cfmiRNA is detectable in plasma of CRC patients and may provide potential biomarker for surgical clearance and residual disease. In addition, it was shown that GNAS1 knock-down did not increase both cell proliferation and migration in the CRC cell lines, RKO and SW620. However, further validation for these findings may enhance the understanding of these molecular markers in invasion-metastatic transformation in CRC