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Little is known about ecosystem structure and nutrient flux in the pelagic zone of seasonal upwelling systems in the tropics, despite their global importance to marine production. The Tropical Eastern Pacific (TEP) is responsible for around 10% of global ocean productivity, largely due to wind-driven seasonal upwelling areas between Mexico and Panama. The Gulf of Panama has a detectable outflow for hundreds of kilometres into the Pacific Ocean and the upwelling system there is an important productivity source in the TEP. In this study, we aim to determine the spatio-temporal patterns in variability of carbon and nitrogen stable isotope composition throughout the pelagic ecosystem of the Bay of Panama in upwelling and non-upwelling conditions, and how these patterns are recorded throughout the ecosystem from primary producers to apex predators. We characterise the stable isotope composition of basal production in the ecosystem to quantify spatial variability during the non-upwelling season. We use the delta N-15 composition outside of upwelling season as an ecosystem baseline and quantify the overall delta N-15 separation between all trophic levels (TL) from primary producers to apex predators (e.g. yellowfin tuna and mahi mahi) within the pelagic ecosystem (2.9 +/- 0.1 parts per thousand per TL). The ecosystem has a relatively simple, linear structure with size-based TL increase. We calculate the predator-prey mass ratio of this ecosystem (c. 113:1 for fishes, 376:1 for the whole ecosystem, uncertainty range: 77:1-1272:1). These values are low for existing estimates in other marine ecosystems, although within the expected range for animals of the mass sampled. The calculated predator-prey mass ratios and maximum TL indicate that this pelagic ecosystem may have a relatively long trophic chain, with inefficient nutrient transfer from low to high TLs. Using a monthly time series of stable isotope values of resident, planktivorous fishes and co-occurring sea surface temperature measurements, we determine nutrient transfer time between primary production and TL3 fish. We calculate a rapid nutrient turnover time within this ecosystem as 0.5-1 month per TL. The incorporation of upwelled nutrients, which are enriched in the C-13, leads to higher consumer delta C-13 values. Carbon isotopes can therefore be used to track timing, duration, and use of upwelling zones. Our findings give novel, empirical insights into the functional ecology of the pelagic ecosystem in the Gulf of Panama, and provide a baseline for comparison and quantification of ecosystem structure and dynamics in the tropics, and in other pelagic upwelling systems.

PurposeThe purpose of this paper is to ascertain whether or not there are differences between college students in Alabama and Hawaii based on three questions: are students concerned about the present/future? What do students know about sustainability? Who is responsible for sustainability?Design/methodology/approachTwo approaches were used to address these questions. First, a summary of sustainability efforts at universities in Alabama and Hawaii is provided. Second, a random sample of 406 undergraduate students at two universities in Alabama (n=258) and at a community college in Hawaii (n=148) were surveyed.FindingsThe data indicate that sustainable programs and practices are being implemented on a number of college campuses in Alabama and in Hawaii. Students surveyed in both states are concerned about wasteful consumption and pollution. Respondents' were similar in their self‐assessed knowledge about sustainability. Respondents were also similar in their views about who is responsible for sustainability. However, a consistently larger proportion of Hawaii respondents expressed concern for and willingness to participate in sustainable practices. So, there seems to be little or no “knowledge gap” when it comes to campus sustainability, but there does seem to be a “commitment gap.” Possible reasons for this are discussed.Originality/valueSince the 1980s, many universities in the USA have elected to incorporate sustainability practices into campus development and day‐to‐day operations. They are now emerging as environmental leaders and innovators. An understanding of students' perceptions of sustainability may give insight into whether or not and how they are likely to engage in sustainable practices.

Although the biographies known collectively as theHistoria Augustapurport to have been written by six different biographers, it has often been thought that their similarities are so numerous that they must be the work of a single author. In this article I shall deal with a piece of linguistic evidence which supports this view.The two scholars who have treated the language of theH.A.in most detail, E. Wölfnin and E. Klebs, attempted to show that certain linguistic features which are not spread evenly among the Scriptores point to multiplicity of authorship.

Transduction of the lac + property by phage P1 among strains of Escherichia coli K12 and Shigella dysenteriae Sh has been studied. When E. coli strains are used both as donors and recipients, transduction gives stable lac + transductants (transduction by integration). Transduction from E. coli lac + donors to strain Sh gives mainly unstable, lac v transductants, in which the lac + genes are apparently associated with some phage P1 genes in a defective prophage, called P1 dl (transduction by lysogenization). A variety of P1 dl elements is postulated to account for the properties of different Sh lac v transductant strains. Some of these strains produce phage lysates that transduce the lac + property at high frequency (HFT lysates), probably because of a high content of phage particles carrying the defective phage element P1 dl . A different type of P1 dl element, called P1 dl w , has been obtained by using HFT lysates from Sh lac v strains to transduce the lac + property in a strain of E. coli that appears to have a deletion of the lac genetic region. The results of lac + transduction by various types of lysates to various recipient strains have been compared, using both untreated and ultraviolet-irradiated lysates. The results are interpreted by assuming that the transducing particles contain genetic elements with various combinations of phage genes and of bacterial genes, and that the transduction type that is obtained, by integration or by lysogenization, depends both on the ability of the transducing elements to lysogenize and on the degree of genetic homology between the donor and the recipient of the transduced bacterial genes. High genetic homology favors integration; low genetic homology hinders integration and allows detection of transductants carrying the transducing element as prophage.

The Commentary deals only with stylistic and linguistic matters. Textual problems are sometimes discussed, but only when they can be illuminated by points of usage. Diverse subjects are treated, but certain themes predominate. Many of the notes are concerned with the history and usage of certain words and stylistic devices down to the end of the first century A.D. Tacitus' originality and idiosyncrasies, and his indebtedness both to contemporary developments in educated usage and to the historiographical tradition, are pointed out. Archaisms, poeticisms, and words of high style are differentiated from words current among the educated classes. Tacitus' vocabulary is compared in artificiality with that of previous historians and other archaising writers of the early Empire. The Controversiae and Suasoriae of the Elder Seneca, the Institutio Oratoria of Quintilian, and the Declamations ascribed to Quintilian have been taken as evidence for the ordinary educated usage of the period. [Abstract continues in thesis ...]