A Non-Perturbative, Finite Particle Number Approach to Relativistic Scattering Theory

We present integral equations for the scattering amplitudes of three scalar particles, using the Faddeev channel decomposition, which can be readily extended to any finite number of particles of any helicity. The solution of these equations, which have been demonstrated to be calculable, provide a non-perturbative way of obtaining relativistic scattering amplitudes for any finite number of particles that are Lorentz invariant, unitary, cluster decomposable and reduce unambiguously in the non-relativistic limit to the non-relativistic Faddeev equations. The aim of this program is to develop equations which explicitly depend upon physically observable input variables, and do not require renormalization or dressing of these parameters to connect them to the boundary states

Feasibility of the modified sequential organ function assessment score in a resource-constrained setting: a prospective observational study.

BackgroundSub-Saharan Africa has a great burden of critical illness with limited health care resources. We evaluated the feasibility and utility of the modified Sequential Organ Function Assessment (mSOFA) score in assessing morbidity and mortality in the National Referral Hospital's intensive care unit (ICU) for one year.MethodsWe conducted a prospective, observational cohort study on patients above 12 years of age admitted to the ICU at Mulago Hospital (Kampala, Uganda). All SOFA scores were determined at admission and at 48 h. We modified the SOFA score by replacing the PaO2/FiO2 ratio with SPO2/FiO2. The primary outcome was ICU mortality.ResultsThis ICU cohort of 118 patients had a mean age of 37 years and an ICU mortality rate of 46.6%. Non-survivors had higher initial (7.7 SD 3.8 vs. 5.5 SD 3.3; p = 0.007), mean (8.1 SD 3.9 vs 4.7 SD 2.6; p < 0.001) and highest mSOFA scores (9.4 SD 4.2 vs. 5.8 SD 3.2; p < 0.001), with an increase of 1.0 (SD 3.1) mSOFA on average after 48 h when compared to survivors (p < 0.001). The area under the receiver operating characteristic curves for each mSOFA category was: initial-0.68, mean-0.76, highest-0.76 and delta mSOFA-0.74. Multivariate logistic regression analysis showed no significant association between mSOFA scores and mortality.ConclusionOur results confirm that calculation of the mSOFA score is feasible for an ICU population in a resource-limited country. More data are needed to test for an association between mSOFA and mortality

Mutual Information Maximization by Data Augmentation for Plankton Classification

Denne masteroppgaven utforsker potensialet for ikke-veiledet maskinlæring for in-situ plankton bildeklassifisering. Oppgaven ble utformet for å adressere begrensningene i bildeklassifisering ved veiledet maskinlæring, hovedsakelig behovet for et omfattende annotert datasett og utfordringen med å klassifisere plankton som ikke er til stede i treningssettet. Ved å benytte Invariant Information Clustering (IIC) og to varianter av Regularized Information Maximization (RIM), overgikk studiet tidligere ulærte teknikker med 11%, og oppnådde en nøyaktighet på 24.9% på NDSB-datasettet. En ny variant av RIM som bruker selektive bildetransformasjoner for augmentering ble introdusert, og overgikk ytelsen til IMSAT metoden. Normalized Mutual Information (NMI) viste seg å være en effektiv evalueringsmetrikk for ikke-veiledet metoder når datasettmerkene ikke er tilgjengelige. Til tross for beregningsbegrensninger og antagelsen om kjente datasettklasser, indikerer funnene betydelig potensiale for ulærte maskinlæringsmetoder i plankton bildeklassifisering. Applikasjon for in-situ klassifisering krever et ekstra manuelt trinn etter klassifisering av en planktonekspert for å merke de klassifiserte gruppene. Til tross for disse begrensningene, antyder resultatene lovende veier for fremtidig forskning. De presenterte metodene markerer fremgang innen feltet for plankton bildeklassifisering, med potensielle fordeler for overvåking av marine økosystemer og studier av miljøpåvirkninger.This thesis explores the potential of unsupervised machine learning methods for in-situ plankton image classification. The research was driven by the need to overcome the limitations of supervised methods, which necessitate extensive annotated datasets and struggle with classifying unseen plankton. Employing Invariant Information Clustering (IIC) and two variants of Regularized Information Maximization (RIM), outperforming previous unsupervised techniques by 11%, reaching an accuracy of 24.9% on the NDSB dataset. A novel variant of RIM using selective image transformations for augmentation was introduced, surpassing the performance of the IMSAT method. Normalized Mutual Information (NMI) proved to be an effective evaluation metric for unsupervised methods when dataset labels are not available. Despite computational constraints and the assumption of known dataset classes, the findings imply a substantial potential for unsupervised machine learning methods in plankton image classification. Application for in-situ classification necessitates an additional manual post classification step by a plankton expert to label clusters. Despite these limitations, the results suggest promising avenues for future research. The presented methods mark an advancement in the field of plankton image classification, with potential benefits for marine ecosystem monitoring and the study of environmental impacts

Matrix Singular Value Decomposition

This thesis starts with the fundamentals of matrix theory and ends with applications of the matrix singular value decomposition (SVD). The background matrix theory coverage includes unitary and Hermitian matrices, and matrix norms and how they relate to matrix SVD. The matrix condition number is discussed in relationship to the solution of linear equations. Some inequalities based on the trace of a matrix, polar matrix decomposition, unitaries and partial isometies are discussed. Among the SVD applications discussed are the method of least squares and image compression. Expansion of a matrix as a linear combination of rank one partial isometries is applied to image compression by using reduced rank matrix approximations to represent greyscale images. MATLAB results for approximations of JPEG and .bmp images are presented. The results indicate that images can be represented with reasonable resolution using low rank matrix SVD approximations

Aggression and Violence Among Young People - The causes and triggering forces of violence and aggressive behaviours among young people

This study will look at what might be the causes and triggering forces that can contribute to the instigation of aggressive behaviours mostly among young people, its expression and manifestation. On a daily basis, we accustomed to turn on our TV for morning news or read a newspaper and learn about an act of violence and aggression towards a follow man or between communities. Aggression has become a natural risk to a level where every area of human condition of existence is characterised by acts of violence, cruelty and destruction. The method that has been used can be referred to the historical method that consists of assembling information through an analysis and reading of different text books and articles. Participation to one’s own culture can be a basic foundation to define humans, but aggression and destructive behaviour can also be considered as part of man inner being. Man can as well lose his unique individual features as part of a group. Being aggressive might mean standing for his own, his beliefs and being forceful, getting on his own way in his dealings and attempting to solve the problems facing him. The individual might appear unfriendly and even prone to hurt others. Since we also encounter contradictions and ambivalence in our daily and social feelings that are built in infancy, not only a social perspective can also be used to explain aggression but also our wrong assessment and interpretation of the situation or through our interactions with others. As I argue in this thesis, before seeing aggression as an acquired and learned response due to the influence of environmental factors, it is necessary to take into consideration the conception of an innate biological determined instinctual drive. However, some provocation factors must be in place for aggression to manifest itself, repressed feelings also are able to reproduce themselves unconsciously and resurface again into consciousness. This study may not be the final answer to problem of aggression but I believe that it carries with it additional information for educators since it deals with a problem which is of social importance, a problem that has become unstoppable and which affects mainly the youth

Rwanda to phase out polluting vehicles by 2040, an efficient strategy to mitigate global warming effects?

Passenger vehicles are major pollutants because on average a typical passenger vehicle emits about 4.6 metric tons of carbon dioxide per year. I highly support the idea that Rwanda joined on November 11, 2021, a group of countries at the COP26 UN climate talks that have made an agreement to end polluting vehicles by 2040. Rwanda is a landlocked country with a 12.95 million population as of 2020(world bank). Rwanda currently has over 221,000 registered vehicles; 83980 are passenger vehicles, 114,900 vehicles (52 percent of those vehicles) are motorcycles and the rest include public transports (buses and minibuses) and trucks for transportation of goods. Because of the high population density and the size of Rwanda, many people use motorcycles and public buses as a mode of transportation to move from place to place

Magnetic Phase Diagram and Metal-Insulator Transition of NiS2-xSex

Magnetic phase diagram of NiS2-xSex has been reexamined by systematic studies of electrical resistivity, uniform magnetic susceptibility and neutron diffraction using single crystals grown by a chemical transport method. The electrical resistivity and the uniform magnetic susceptibility exhibit the same feature of temperature dependence over a wide Se concentration. A distinct first order metal-insulator (M-I) transition accompanied by a volume change was observed only in the antiferromagnetic ordered phase for 0.50<x<0.59. In this region, the M-I transition makes substantial effects to the thermal evolution of staggered moments. In the paramagnetic phase, the M-I transition becomes broad; both the electrical resistivity and the uniform magnetic susceptibility exhibit a broad maximum around the temperatures on the M-I transition-line extrapolated to the paramagnetic phase.Comment: 6 pages, 8 figures, corrected EPS fil

Environmental Pollution through Multiple Integrated Hazard Sources in their Shared Environment: A Case Study of Muvumba Community, Rwanda

A community-based One Environmental Health Toxicology (OEHT) study is a holistic approach to examine environmental toxicant exposure in vulnerable communities. It is a novel approach evaluating health effects of environmental toxicant exposure on individuals and/or whole communities, in concert with addressing the health of animals, and of the ecosystem. This approach is novel in Africa. This study first identified a vulnerable community in Rwanda and investigated environmental pollutants impacting the health of the community. The objective of the study was to determine environmental contaminants impacting the Muvumba community, a vulnerable agricultural community in Rwanda. The study was conducted in a vulnerable agricultural community with significant pesticide and fertilizer use and linked to the Akagera-Nile water ecosystem. The Rwanda Institute for Conservation Agriculture (RICA) campus employing conservation agriculture and One Health (OH) principles was selected as a control site. Environmental water was passively sampled for pesticides and harmful algal blooms. Grab drinking water samples were collected from both sites and analyzed for pesticides, organic contaminants, and heavy metals. Rice from Muvumba was analyzed for pesticides and metallic elements.&nbsp; Environmental water samples from Muvumba river tested positive for three organophosphorus pesticides (diazinon, malathion, and profenofos), while imidacloprid was detected in water samples from RICA. Microcystins were not detected in any of the water bodies. Environmental and drinking water samples tested positive for diisononyl phthalate, bis(2-ethylhexyl) phthalate, and ricinine. Lead and arsenic were detected in rice samples from the Muvumba site. The findings of this community based OEHT indicate a significant public health and environmental concern and are vital in advancing a holistic integrated one-health research approach to safeguard human, animal and ecosystem health and ensure sustainable development in Africa

Testing for the Uncovered Interest Rate Parity (UIP) in Developing Countries: The Case of Rwanda

The aim of this paper is to assess the link between interest rates and exchange rates in Rwanda under the framework of uncovered interest rate parity (UIP) hypothesis.The parity condition states that the difference between the interest rates of two countries is equal to the expected depreciation between the countries’ currencies. The paper uses data spanning the January 2004 to December 2016 period. The paper uses the spot exchange rate, risk premium, deposit interest rates as domestic variables while the USA deposit rates are used as foreign interest rates. Due to its desirable properties especially in terms of handling rational expectations models, the Generalized Method of Moments (GMM) is used to estimate the UIP equation for Rwanda before carrying out several others diagnostic tests to assess the robustness of results. Empirical results show that interest rate differentials, risk premium and the intercept are statistically not significant. These results imply that the UIP condition does not hold for Rwanda under the period of study, which is consistent with other empirical findings in developing countries. The lack of empirical support for the UIP hypothesis in Rwanda may open up arbitrage opportunities for investors with rational expectations.Indeed, the Modelling and forecasting team should review the UIP equation in the Forecasting and Policy Analysis System (FPAS) macro-model so as to give more attention to non-interest sensitive determinants of exchange rate dynamics in Rwanda. Keywords: Uncovered Interest rate Parity (UIP), Generalized Method of Moments (GMM) JEL Classification: C2, E4, E6, F2, F