Avian song learning is an important model system for understanding vocal learning in humans and other animals. Laboratory studies indicate that social interactions are critical for song learning, but field observations show that territorial males are aggressive to intruders, raising the question of whether young birds are tolerated, much less tutored in the wild. We examined how adult song spar...

The atmospheric Ar/N2 ratio is expected to be useful as a tracer of air-sea heat exchange, but this application has been hindered in part due to sampling artifacts. Here we show that the variability in δ(Ar/N2) due to thermal fractionation at the inlet can be on the order of 40–80 per meg, and we introduce the use of an aspirated solar shield that successfully minimizes such fractionation. The ...

Editor's Note: It seems appropriate, in this issue of JSS containing the ®ndings of our annual Top Scholars/Institutions study, to pay tribute to the persistent authors who make a journal like this, and a study like that, possible. In their honor, we dedicate the following humorous, anonymously-authored, letter! Dear Sir, Madame, or Other: Enclosed is our latest version of Ms. #1996-02-22-RRRRR...

Recently, fuzzy linear programming problems have been considered by many. In the literature of fuzzy linear programming several models are offered and therefore some various methods have been suggested to solve these problems. One of the most important of these problems that recently has been considered; are Fully Fuzzy Linear Programming (FFLP), which all coefficients and variables of the prob...

Flocks participating in sire referencing schemes can achieve greater genetic gains than those achievable by within-flock selection. However, requirements for joining these schemes can be prohibitive to some producers. The objectives of this study were to determine whether less restrictive schemes or schemes of shorter duration could achieve rates of gain and reduce inbreeding as efficiently as ...

While holding great development opportunities to be seized, Africa has been identified as particularly vulnerable to climate changes, and the ZRB is no exception to that. With increasing demands to the Zambezi system in terms or water and energy, and rising challenges in the form of less runoff due to climate change, it is paramount to plan ahead. In particular, it must be understood how major ...

T the ripe age of eighty-four Lloyd Morgan has passed away. jje wag for many years the distinguished and greatlyeloved Principal of University College, and when the College deceived its charter in 1909 converting it into Bristol diversity Lloyd Morgan was designated the first Vicehancellor. He relinquished this office almost immediately, nd Sir Igambard Owen was appointed in his stead. His ecis...