On the Factor Refinement Principle and its Implementation on Multicore Architectures

The factor refinement principle turns a partial factorization of integers (or polynomi­ als) into a more complete factorization represented by basis elements and exponents, with basis elements that are pairwise coprime. There are lots of applications of this refinement technique such as simplifying systems of polynomial inequations and, more generally, speeding up certain algebraic algorithms by eliminating redundant expressions that may occur during intermediate computations. Successive GCD computations and divisions are used to accomplish this task until all the basis elements are pairwise coprime. Moreover, square-free factorization (which is the first step of many factorization algorithms) is used to remove the repeated patterns from each input element. Differentiation, division and GCD calculation op­ erations are required to complete this pre-processing step. Both factor refinement and square-free factorization often rely on plain (quadratic) algorithms for multipli­ cation but can be substantially improved with asymptotically fast multiplication on sufficiently large input. In this work, we review the working principles and complexity estimates of the factor refinement, in case of plain arithmetic, as well as asymptotically fast arithmetic. Following this review process, we design, analyze and implement parallel adaptations of these factor refinement algorithms. We consider several algorithm optimization techniques such as data locality analysis, balancing subproblems, etc. to fully exploit modern multicore architectures. The Cilk++ implementation of our parallel algorithm based on the augment refinement principle of Bach, Driscoll and Shallit achieves linear speedup for input data of sufficiently large size

Crack Spread and its forecasting analysis. An empirical analysis using VAR and ARIMA model.

This thesis strives to describe crack spread which refers to the difference between the price of crude oil and the price of refined products extracted from it. It has a stable price movement throughout the last decade. But last year, there was a huge price hike. This paper showed the relationship between crack spread and WTI crude oil price movement. Also, it analyzed the price forecasting for both cases using two different models, namely ARIMA and VAR

Developing Speaking Skill: Barriers Faced by the Bangladeshi EFL Learners

This study aims at investigating the prevailing barriers for developing English speaking skill faced by the undergraduate students in Bangladesh. The attempt was to locate the importance of speaking proficiency in English as one of the basic skills of a language in this “English” era. In this global age, the use of English has been inevitable and more often we cannot but use English in different phases of our life. But Bangladeshi EFL learners often fail to attain proper speaking proficiency for some reasons. The reasons behind the incompetence in speaking skill are many and some of them are the influence of mother tongue, lack of vocabulary, lack of practice, unfavorable environment, teachers’ non-cooperation, shyness, fear, language ‘fossilization’ etc. Moreover, students do not get the opportunity to develop English speaking skill in a ‘natural’ environment. The nature of the study is quantitative and the data collection tool is a questionnaire. This paper pinpoints all those problems and presents plausible recommendations in order for developing English speaking skill

Hidden Symmetries in Classical Mechanics and Related Number Theory Dynamical System

Classical Mechanics consists of three parts: Newtonian, Lagrangian and Hamiltonian Mechanics, where each part is a special extension of the previous part. Each part has explicit symmetries (the explicit Laws of Motion), which, in turn, generate implicit or hidden symmetries (like the Law of Conservation of Energy, etc). In this Master\u27s Thesis, different types of hidden symmetries are considered; they are reflected in the Noether Theorem and the Poincare Recurrence Theorem applied to Lagrangian and Hamiltonian Systems respectively. The Poincare Recurrence Theorem is also applicable to some number theory problems, which can be considered as dynamical systems. In this thesis, we study the problem The first digits of the powers of integers . A dynamical system interpretation for this problem allows to apply the Poincare Recurrence Theorem to find several unexpected hidden symmetries like rotations on the circle and on the torus, as well as hidden arithmetic progressions in the set of all the exponents

Observation on analgesic efficacy and adverse effects of intrathecal administration of bupivacaine versus bupivacaine-midazolam combination in lower limb surgeries in a tertiary care hospital

Background: Postoperative pain relief can improve functionality, reduce physiological and emotional morbidity and improve quality of life. Neuraxial blocks not only reduce the incidence of venous thrombosis, pulmonary embolism, cardiac complications, bleeding transfusion requirements and respiratory depressions but also provide effective postoperative analgesia. One of the methods of providing postoperative is to prolong the duration of intrathecally administered bupivacaine by using additives such as opioids such as midazolam, clonidine and ketamine. Intrathecal administration of midazolam induces antinociceptive effects in humans. The present study was undertaken to evaluate the additive analgesic effects of intrathecal midazolam in combination with bupivacaine in lower limb surgeries in a tertiary care hospital and to compare the results with the use of bupivacaine alone. The aim of this study was to observe and compare the quality of spinal anaesthesia and occurrence of side effects in thirty cases administered with bupivacaine and thirty cases administered with bupivacaine-midazolam combination.Methods: Sixty cases admitted for lower limb surgery were divided into equal groups I and II. Cases in group I received intrathecal bupivacaine while those in group II received intrathecal combination of bupivacaine and midazolam. Data regarding quality of anesthesia and side effects were recorded and compared.Results: There was a significantly higher duration of a pain-free period in cases administered with intrathecal combination of bupivacaine and midazolam.Conclusions: Addition of preservative free midazolam to 0.5% hyperbaric bupivacaine for subarachnoid block prolongs the duration of effective analgesia as compared to bupivacaine alone. The utilization of intrathecal midazolam also decreases the incidence of postoperative nausea-vomiting.

Posterior reversible encephalopathy syndrome (PRES) after bevacizumab therapy for metastatic colorectal cancer.

Posterior reversible encephalopathy syndrome (PRES) is an increasingly recognizable neuro-clinical syndrome. Clinical and neurological manifestations of PRES include hypertension, headache, encephalopathy, seizures, and symmetrical white matter changes on brain MRI. Most common precipitants of PRES are acute medical illness, hypertensive crisis, eclampsia, immunosuppressive therapy, and chemotherapy. Bevacizumab is a monoclonal antibody that halts angiogenesis by inhibiting vascular endothelial growth factor. It has gained widespread popularity in oncology world especially for metastatic and recurrent cancers due to its inherent ability to stop angiogenesis; a vital step for tumor growth. Bevacizumab has also been implicated as the cause of PRES due to dysregulation of the blood-brain barrier. We are reporting a case of PRES induced by Bevacizumab in a patient of colorectal cancer

A questionnaire based institutional assessment of ‘knowledge’, ‘attitude’ and ‘practice’ about bio-ethics in clinical research among postgraduate residents

Background: Research ethics govern the standards of conduct for scientific researchers. Post graduate residents are one of the key stakeholders in clinical research. Therefore, the present study is designed to assess the Knowledge, Attitude and Practice about bio-ethics in clinical research among post-graduate residents.Methods: A self-administered pretested questionnaire was given to 40 students selected on the basis of convenience sampling. The questionnaire consists of questions related to knowledge and attitude toward principles and practice of bioethics in clinical research, informed consent, and role of the ethics committee in the institution. Descriptive statistics was used to analyse the results.Results: 70% of the students have formally taken Hippocratic Oath. Knowledge, attitude, and practice regarding Institutional Ethics Committee, and informed consent were more among final year students when compared to their juniors. Source of knowledge of bioethics were multiple. Department lectures were not a preferred mode of learning.Conclusions: There is an urgent need to include practical education of ethics to bridge the gap in the knowledge, attitude, and practices regarding ethics in clinical practice and research

Expansion of aquaculture threatens the existence of wetlands in Bangladesh

Despite positive role of aquaculture in food production, the practice may impact the environment negatively and it is difficult to quantify the loss. In this study, we assessed land use changes in four important wetlands (Hardoho Beel, Angrar Beel, Shaoil Beel and Gopalpur Beel) of Bangladesh through analysis of historical satellite images (1990 – 2020) to show how expansion of aquaculture activities threatens the existence of freshwater wetlands. Since 1990, the water area of all four wetlands decreased significantly over time (all p < 0.001). Mean yearly loss of 47.9 ± 79.3 ha, 99.2 ± 185.5 ha, 51.2 ± 61.9 ha and 2.6 ± 4.7 ha were recorded for Hardoho Beel, Angrar Beel, Shaoil Beel and Gopalpur Beel respectively. A decreasing trend in wetland area was recorded in all wetlands, primarily due to excavation of aquaculture ponds. In 2020, aquaculture ponds represented 72% of the core wetland areas. Two wetlands (Hardoho and Gopalpur) were almost totally lost and converted to aquaculture ponds and agricultural lands. This study concludes that the existence of freshwater wetlands in Bangladesh is at stake and recommends further studies to determine its impacts on people's livelihood and biodiversity

A prospective study of drug utilization in patients attending ophthalmology outpatient department at KBN teaching and general hospital of Gulbarga, India

Background: Drug utilization studies are an important part of rational use of drugs. Assessment of drug use pattern especially in developing countries is becoming increasingly necessary to promote the rational use of drugs. This study was planned to prospectively assess the drug utilization pattern in Ophthalmology outpatient department at KBN teaching and General hospital.Methods: After approval from Ethics Committee, the prescriptions of 1000 outpatients were analyzed using a predesigned form to record information from the OPD prescriptions. Mentioned WHO drug use indicators and additional indices were analyzed: Average number of drugs per prescription, number of encounters with antibiotics, percentage of encounters with injections, percentage of drugs prescribed by their generic names, percentage of drugs prescribed from the National Essential Drug List (NEDL), etc.Results: Prescription analysis showed that the average number of drugs per prescription was 2.6. The drugs were prescribed in the several forms, predominant dosage form been topical eye drops (69.58%) followed by tablets (11.98%), ointments (10.17%) and capsules (6.6%). The ‘dosage form’ was indicated for all of the drugs prescribed, the ‘frequency’ of drug administration was present in 96.5% of the drugs, and the duration of treatment for 82% of the drugs prescribed. Topical Antimicrobial agents were the most commonly prescribed drugs. followed by anti-inflammatory and anti-allergic, lubricants, anti-glaucoma drugs, etc. Percentage of drugs prescribed by generic name and from NEDL was 7.98% and 55 % respectively.Conclusions: The prescription writing errors were less, however, there was very low generic prescribing and inadequate information about the duration of therapy in many prescriptions. Generic prescribing can be improved. Duration of therapy should be mentioned in all prescriptions. It is essential that appropriate guidelines on the use of topical antimicrobials are required to ensure rational prescribing

A prospective study of antimicrobial drug utilization in infective diseases in pediatrics at Navodaya Medical College Hospital of Raichur, Karnataka, India

Background: There is increased concern regarding the inappropriate use of antimicrobials resulting in emergence of resistant strains, unnecessary adverse effects and poor therapeutic outcome. This present study has been taken up with a view to analyze the use of various antimicrobial agents alone and/or in combination to combat diseases of infective origin in a proposed manner.Methods: This was a prospective study carried out for a period of 1 year from January 2011 to December 2011. The prescriptions of all eligible patients were reviewed on daily basis and all the relevant data were retrieved to assess the utilization pattern of antimicrobials and also their safety and potential interactions.Results: A total of 500 patients were selected randomly who satisfied the inclusion criteria. Of the total selected patients with infectious diseases, 493 patients (98.6%) received one or more antimicrobials. Use of antimicrobials was high in the age group of ‘6 months to 3 years’, ‘rural patients’ constituted 62% and were mostly from ‘Lower Socio-economic status’ (46%). Respiratory diseases constituted 38% of the patients. Fever was the notable symptom in 68.4%. Cephalosporins (48.6%) were the most frequently prescribed class of antimicrobials. Combination of ‘Parenteral therapy followed by oral therapy’ was the preferred route in 92%, and a combination of two antimicrobials was seen in 34.4%. Majority of the patients (81%) were discharged on advice and most of the patients (37.6%) had duration of stay of 7-9 days. 25.8% reported ‘Adverse Drug Reactions’ including predictable and unpredictable reactions.Conclusions: Antimicrobial prescribing is common in pediatric infectious diseases. As inappropriate usage of systemic antimicrobials was observed, it is essential that appropriate guidelines on the use of systemic antimicrobials are implanted to ensure rational prescribing of antimicrobials