dPanther for Community Partners

Slides from presentation dPanther for Community Partners, on May 11, 2023

Should oil trading companies possess their own tankers ?

The purpose of this report is to understand if it would make sense for oil trading companies to purchase and operate oil tankers. The report begins by defining the current concept of trading. In fact, trade is defined as the action of buying and selling goods. The concept has evolved from prehistoric times to today where the trade industry involves millions of transactions completed each day. Moreover, the current report provides an overview of commodity trading in Switzerland and Geneva, which are popular for their commodity trading sector as Geneva is home to the oil trading industry. This project provides a snapshot of the crude oil sector with details about historical and current trends from different parts of the world such as in the United States, where oil production has been increasing drastically over the last years, or in Asia, where the demand for oil is constantly growing. Furthermore, information on key traders of the oil industry in terms of oil traded volume is established. Then, the report exposes the shipping market by looking at five different types of tankers shipped by oil trading companies and the most commonly used oil routes. Further, the profitability of each tanker under a time charter party is analyzed by comparing both capital and operating costs with freight rates. It is observed that smaller tankers were more profitable in 2012 and 2013 than larger tankers. Moreover, it results that operating and financial costs are fairly predictable and stable, while freight rates have the specificity of being volatile and unpredictable. Furthermore, it is discussed how major oil trading companies relate to shipping in terms of tanker ownership. Generally, oil traders don’t purchase oil tankers but prefer to charter them through time charter. It is also discovered that oil trading companies are slightly heading to a medium asset strategy as their fixed assets increase constantly. Moreover, the report discusses the differences between purchasing a tanker in the second hand market or in the new building market. Finally, it is explained that oil tankers provide optionality in terms of time, location and lot size

Collective iteration behavior for online social networks

Understanding the patterns of collective behavior in online social network (OSNs) is critical to expanding the knowledge of human behavior and tie relationship. In this paper, we investigate a specific pattern called social signature in Facebook and Wiki users’ online communication behaviors, capturing the distribution of frequency of interactions between different alters over time in the ego network. The empirical results show that there are robust social signatures of interactions no matter how friends change over time, which indicates that a stable commutation pattern exists in online communication. By comparing a random null model, we find the that commutation pattern is heterogeneous between ego and alters. Furthermore, in order to regenerate the pattern of the social signature, we present a preferential interaction model, which assumes that new users intend to look for the old users with strong ties while old users have tendency to interact with new friends. The experimental results show that the presented model can reproduce the heterogeneity of social signature by adjusting 2 parameters, the number of communicating targets m and the max number of interactions n, for Facebook users, m=n=5, for Wiki users, m=2 and n=8. This work helps in deeply understanding the regularity of social signature

Architecture of the chromatin remodeler RSC and insights into its nucleosome engagement.

Eukaryotic DNA is packaged into nucleosome arrays, which are repositioned by chromatin remodeling complexes to control DNA accessibility. The Saccharomyces cerevisiae RSC (Remodeling the Structure of Chromatin) complex, a member of the SWI/SNF chromatin remodeler family, plays critical roles in genome maintenance, transcription, and DNA repair. Here, we report cryo-electron microscopy (cryo-EM) and crosslinking mass spectrometry (CLMS) studies of yeast RSC complex and show that RSC is composed of a rigid tripartite core and two flexible lobes. The core structure is scaffolded by an asymmetric Rsc8 dimer and built with the evolutionarily conserved subunits Sfh1, Rsc6, Rsc9 and Sth1. The flexible ATPase lobe, composed of helicase subunit Sth1, Arp7, Arp9 and Rtt102, is anchored to this core by the N-terminus of Sth1. Our cryo-EM analysis of RSC bound to a nucleosome core particle shows that in addition to the expected nucleosome-Sth1 interactions, RSC engages histones and nucleosomal DNA through one arm of the core structure, composed of the Rsc8 SWIRM domains, Sfh1 and Npl6. Our findings provide structural insights into the conserved assembly process for all members of the SWI/SNF family of remodelers, and illustrate how RSC selects, engages, and remodels nucleosomes