Perfect state transfer, graph products and equitable partitions

We describe new constructions of graphs which exhibit perfect state transfer on continuous-time quantum walks. Our constructions are based on variants of the double cones [BCMS09,ANOPRT10,ANOPRT09] and the Cartesian graph products (which includes the n-cube) [CDDEKL05]. Some of our results include: (1) If $G$ is a graph with perfect state transfer at time $t_{G}$, where t_{G}\Spec(G) \subseteq \ZZ\pi, and $H$ is a circulant with odd eigenvalues, their weak product $G \times H$ has perfect state transfer. Also, if $H$ is a regular graph with perfect state transfer at time $t_{H}$ and $G$ is a graph where t_{H}|V_{H}|\Spec(G) \subseteq 2\ZZ\pi, their lexicographic product $G[H]$ has perfect state transfer. (2) The double cone $\overline{K}_{2} + G$ on any connected graph $G$, has perfect state transfer if the weights of the cone edges are proportional to the Perron eigenvector of $G$. This generalizes results for double cone on regular graphs studied in [BCMS09,ANOPRT10,ANOPRT09]. (3) For an infinite family \GG of regular graphs, there is a circulant connection so the graph K_{1}+\GG\circ\GG+K_{1} has perfect state transfer. In contrast, no perfect state transfer exists if a complete bipartite connection is used (even in the presence of weights) [ANOPRT09]. We also describe a generalization of the path collapsing argument [CCDFGS03,CDDEKL05], which reduces questions about perfect state transfer to simpler (weighted) multigraphs, for graphs with equitable distance partitions.Comment: 18 pages, 6 figure

Corruption and discrimination in Douala metropolis public hospitals of Cameroon

Abstract. The problem that arises is how the State official in a monopoly situation maximizes the value of bribes collected, by selling public services to users? To answer this question, we show that the State agent in a monopoly situation can discriminate users according to their characteristics in order to collect more possible bribes. The Shleifer and Vishny’ simple monopoly model is therefore limited. The survey of patients of nine public hospitals in Douala revealed the existence of two forms of corruption at consultation: corruption without theft and corruption with theft. An evaluation of maximizing the earnings of medical doctors using odds ratios, showed that in the pursuit of these gains and whatever the form of corruption practiced, the State agent plays not only on amounts of bribes paid, but also on users’ characteristics. However, for amounts between 3,000 FCFA and 5,000 FCFA, our results revealed that the doctor will tend to practice the form of corruption without theft on men, the wealthiest, the learned and the old where he/she would draw the greatest possible gain.Keywords. Corruption with and without theft, Discrimination at first degree, Health system, Odds ratios, Cameroon.JEL. D40, I10, I14, I15

Corruption and health care provision: An extension of the Shleifer and Vishny’ Model

Abstract. The problem that arises is how the State official in a monopoly situation maximizes the value of bribes collected, by selling public services to users? To answer this question, we show first that in the case of health care provision, the Shleifer and Vishny’ simple monopoly model which highlights two forms of corruption (with theft and without theft) is limited insofar as it underestimates not only the value of bribes likely to be collected, but also the loss of income that corrupt practices cause to public services. Our model rather reveals that the State agent in a monopoly situation can discriminate users according to their characteristics in order to collect more possible bribes. Indeed, our model shows that when a medical doctor maximizes its earnings and whatever the form of corruption practiced, he plays not only on amounts of bribes paid and a part of the official price, but also on users’ characteristics. However, for some amounts the State agent will tend to practice the form of corruption without theft on certain users’ characteristics where he/she would draw the greatest possible gain.Keywords. Corruption with and without theft, Discrimination at first degree, Lerner`s index, Profit-sharing scheme, Health system.JEL. D40, I10, I14, I15

Corruption Forms and Heath Care Provision in Douala Metropolis Public Hospitals of Cameroon

Abstract. This study analyzes and highlights the most practised forms of corruption in public hospitals of Douala metropolis in Cameroon, namely corruption with theft and that without theft. The results of our analyzes show a predominance of the form without theft, this regardless of the hospital, and this allowed us to classify hospitals based on the dominant form. It appears that the General and Deido Hospitals are health facilities where corruption without theft is the least and the most practiced respectively, while the Cité des Palmiers and New Bell hospitals are those where corruption with theft is the least and the most practiced. An estimate through odds ratios revealed for instance that the odds would be about 5.46 times higher that the form without theft is not practiced at the General hospital compared to other hospitals, and about 11.11 times that it is practiced at Deido hospital compared  to all hospitals.Keywords. Corruption forms, Health system, Odds ratio, Cameroon.JEL. I10, I14, I15

Processing of Electronic Health Records using Deep Learning: A review

Availability of large amount of clinical data is opening up new research avenues in a number of fields. An exciting field in this respect is healthcare, where secondary use of healthcare data is beginning to revolutionize healthcare. Except for availability of Big Data, both medical data from healthcare institutions (such as EMR data) and data generated from health and wellbeing devices (such as personal trackers), a significant contribution to this trend is also being made by recent advances on machine learning, specifically deep learning algorithms

Evolution of histone 2A for chromatin compaction in eukaryotes.

During eukaryotic evolution, genome size has increased disproportionately to nuclear volume, necessitating greater degrees of chromatin compaction in higher eukaryotes, which have evolved several mechanisms for genome compaction. However, it is unknown whether histones themselves have evolved to regulate chromatin compaction. Analysis of histone sequences from 160 eukaryotes revealed that the H2A N-terminus has systematically acquired arginines as genomes expanded. Insertion of arginines into their evolutionarily conserved position in H2A of a small-genome organism increased linear compaction by as much as 40%, while their absence markedly diminished compaction in cells with large genomes. This effect was recapitulated in vitro with nucleosomal arrays using unmodified histones, indicating that the H2A N-terminus directly modulates the chromatin fiber likely through intra- and inter-nucleosomal arginine-DNA contacts to enable tighter nucleosomal packing. Our findings reveal a novel evolutionary mechanism for regulation of chromatin compaction and may explain the frequent mutations of the H2A N-terminus in cancer