International Partnerships, Foreign Control and Income Levels: Theory and Evidence

We analyze the effects of different regimes of control rights over critical resources on the total domestic income of open economies. We consider home control, foreign control, and international partnerships in a theoretical model where contracts are incomplete, resource exploitation requires local capital, and foreign technologies are more efficient. Enacting foreign control is never optimal, and assigning complete residual rights to foreign ?firms reduces domestic income. Two testable predictions are derived. First, international partnerships tend to generate higher domestic income than foreign control. Second, the typical regime choice is either partnership or foreign control when the international relative pro?tability of the domestic resource endowment is high or intermediate, and home control with low relative pro?tability. We test these predictions using a new dataset on petroleum ownership structures for up to 68 countries between 1867-2008, ?finding strong empirical support for the theoretical results.Property rights, control rights, income, oil, panel data

Studies towards the biomimetic synthesis of the stephacidin family of natural products and the concise and versatile synthesis of d,l-brevianamide B, C-12A-epi-malbrancheamide and structurally related analogs

2006 Fall.Includes bibliographical references.The total synthesis of stephacidin A, avrainvillamide and stephacidin B was envisioned to proceed through a biomimetic intramolecular Diels-Alder cylcoaddition. The Diels-Alder precursor was thought to come from the coupling of (L)-prolinamide with a α-ketoacid indole, which would subsequently form the requisite azadiene. While the desired α-ketoacid indole was not stable enough to be synthetically formed, a pseudo- α-ketoacid was successfully designed. The coupling of this vinyl ether carboxylic acid indole moiety with (L)-prolinamide provides an interesting intramolecular Diels-Alder (IMDA) precursor, which might prove to be a useful synthetic prototype for the IMDA. A similar coupling between a pseudo-α-ketoacid and (L)-prolinamide was applied to a different system of compounds, which led to a biomimetically-inspired intramolecular Diels-Alder reaction that diastereoselectively formed the characteristic bicyclo[2.2.2]diazaoctane core of the brevianamides. A concise synthesis of d,l-brevianamide B was successfully designed through a Fischer indole reaction of the key tricyclic IMDA cycloadduct and phenyl hydrazine. This IMDA / Fischer indole route to form the indolic bicyclo[2.2.2]diazaoctane core has proven to be a versatile method to access C-12a-epi-malbrancheamide and structurally related analogs for biological activity studies

Peri-implant disease: What we know and what we need to know

Peri-implant disease is a serious problem that plagues today's dentistry, both in terms of therapy and epidemiology. With the expansion of the practice of implantology and an increasing number of implants placed annually, the frequency of peri-implant disease has greatly expanded. Its clinical manifestations, in the absence of a globally established classification, are peri-implant mucositis and peri-implantitis, the counterparts of gingivitis and periodontitis, respectively. However, many doubts remain about its features. Official diagnostic criteria, globally recognized by the dental community, have not yet been introduced. The latest studies using metagenomic methods are casting doubt on the assumption of microbial equivalence between periodontal and peri-implant crevices. Research on most of the features of periimplant disease remains at an early stage; moreover, there is not a commonly accepted treatment for it. In any case, although the evidence so far collected is limited, we need to be aware of the current state of the science regarding this topic to better understand and ultimately prevent this disease

Segregation in Networks

International audienc