Bilateral pheochromocytomas in MEN2A syndrome: a two-institution experience

postprin

Rationale and design of the screening of pulmonary hypertension in systemic lupus erythematosus (SOPHIE) study

published_or_final_versio

Trading or coercion? Variation in male mating strategies between two communities of East African chimpanzees

Across taxa, males employ a variety of mating strategies, including sexual coercion and the provision, or trading, of resources. Biological Market theory (BMT) predicts that trading of commodities for mating opportunities should exist only when males cannot monopolise access to females and/or obtain mating by force, in situations where power differentials between males are low; both coercion and trading have been reported for chimpanzees (Pan troglodytes). Here, we investigate whether the choice of strategy depends on the variation in male power differentials, using data from two wild communities of East African chimpanzees (P.t. schweinfurthii): the structurally despotic Sonso community (Budongo, Uganda) and the structurally egalitarian M-group (Mahale, Tanzania). We found evidence of sexual coercion by male Sonso chimpanzees, and of trading—of grooming for mating—by M-group males; females traded sex for neither meat nor protection from male aggression. Our results suggest that the despotism–egalitarian axis influences strategy choice: male chimpanzees appear to pursue sexual coercion when power differentials are large and trading when power differentials are small and coercion consequently ineffective. Our findings demonstrate that trading and coercive strategies are not restricted to particular chimpanzee subspecies; instead, their occurrence is consistent with BMT predictions. Our study raises interesting, and as yet unanswered, questions regarding female chimpanzees’ willingness to trade sex for grooming, if doing so represents a compromise to their fundamentally promiscuous mating strategy. It highlights the importance of within-species cross-group comparisons and the need for further study of the relationship between mating strategy and dominance steepness

An equivalent circuit model approach to the numerical modelling of a p-n solar cell and photodetector

With the transmission line equivalent circuit model, the solution of the set of coupled nonlinear partial differential equations governing the carrier transport in semiconductor is converted to a circuit analysis problem. Nonlinear circuit analysis techniques call be employed. In this work, a different approach to computing the model equations in numerical form is presented. The equivalent circuit model is expanded to the simulation of photoilluminated devices by adding the photoexcitation into the circuit model. The details of the modelling techniques are described. The approach was demonstrated by a p-n junction solar cell. The model was also applied to the analysis of a reverse-bias p-n photodetector

Catalytic asymmetric synthesis of protected tryptophan regioisomers

Tryptophan 1 (Trp) is superior to all other naturally occurring peptide residues in its ability to bind cations (the cation-a interaction). In an effort to expand the toolbox of Trp-like amino acids, in this note we report catalytic asymmetric syntheses of Trp regioisomers 2a-e, where the alanine unit is attached not to C-3 of indole but to C-2, C-4, C-5, C-6, or C-7. Excellent asymmetric induction is obtained in each case (generally >97\% ee). Ab initio calculations suggest that the indole nuclei of 2a-e will bind Na+ with the same affinity as that of Trp

A technology-independent methodology of placement generation for analog circuit

An automatic placement system with emphasis on technology independent methodology and device matching consideration for analog layout design is presented. A novel optimization approach based on circuit partitioning, simulated annealing and branch-and-bound algorithm is proposed to solve the placement problem. The move set used to generate perturbations for annealing is capable of arriving at any topological placement. The branch-and-bound is modified to rake circuit performance into consideration. Results of two silicon proven designs generated by the system demonstrate an 8X cycle time reduction as compared to a manual approach

Pregate oxidation treatment using radio frequency activated nitrogen in a rapid thermal reactor

A rapid thermal treatment in nitrogen could be inserted immediately before the gate oxidation step in a typical process flow for making metal-oxide-semiconductor field effect transistors. The treatment, performed in a radio frequency induction heated single-wafer rapid thermal reactor, is used to reduce the subsequent oxidation rate and to incorporate nitrogen in the resulting gate dielectrics. It is believed that activated molecular or atomic nitrogen is generated in the rapid thermal reactor and is responsible for the slight nitridation of the exposed silicon area during the rapid thermal treatment. Potential radiation damage to the silicon area is minimized by activating the nitrogen remotely from the wafer chamber. The effects of the nitrogen flow rate and the temperature during the treatment process on the kinetics of the subsequent oxidation in a regular furnace and the chemical composition of the resulting gate dielectrics are studied. Potential use of the proposed treatment in making scaled devices is discussed. (C) 1999 The Electrochemical Society. S0013-4651(97)10-080-5. All rights reserved