Molt Migration of Scoters at Cape Peirce, Alaska

There is presently little specific information on the molt migrations of scoters in the Nearctic. We conducted migration watches from 21 June to 31 July 1984 (total of 96 h) and from 5 to 15 July 1985 (total of 36 h) during daylight hours to estimate abundance and species composition of scoters engaged in a molt migration at Cape Peirce, southeast Bering Sea, Alaska. We counted 22,897 scoters moving west past the observation site in 1984, the year in which we probably made observations over most of the migration period. Allowing for daylight hours without watches, an estimated 66,500 scoters passed in 1984. Peak passage occurred on 11 July in both years. Species composition of migrants in 1984 was approximately 77% white-winged scoters (Melanitta fusca), 12% surf scoters (M. perspicillata), and 11% black scoters (M. nigra). Most of the migrants were adult males, probably migrating from breeding grounds in Interior Alaska. Our findings suggest that a large and presently undescribed molting area of white-winged scoters exists somewhere in the waters of western Alaska or eastern Siberia.Key words: scoters, seaducks, molt migration, Cape Peirce, Togiak National Wildlife Refuge, Bering Sea, AlaskaMots clés: macreuses, canards de mer, migration d’oiseaux ayant effectué la mue, Cape Peirce, Togiak National Wildlife Refuge, mer de Béring, Alask

A systematic comparison of triterpenoid biosynthetic enzymes for the production of oleanolic acid in Saccharomyces cerevisiae

Triterpenoids are high-value plant metabolites with numerous applications in medicine, agriculture, food, and home and personal care products. However, plants produce triterpenoids in low abundance, and their complex structures make their chemical synthesis prohibitively expensive and often impossible. As such, the yeast Saccharomyces cerevisiae has been explored as an alternative means of production. An important triterpenoid is oleanolic acid because it is the precursor to many bioactive triterpenoids of commercial interest, such as QS-21 which is being evaluated as a vaccine adjuvant in clinical trials against HIV and malaria. Oleanolic acid is derived from 2,3-oxidosqualene (natively produced by yeast) via a cyclisation and a multi-step oxidation reaction, catalysed by a β-amyrin synthase and a cytochrome P450 of the CYP716A subfamily, respectively. Although many homologues have been characterised, previous studies have used arbitrarily chosen β-amyrin synthases and CYP716As to produce oleanolic acid and its derivatives in yeast. This study presents the first comprehensive comparison of β-amyrin synthase and CYP716A enzyme activities in yeast. Strains expressing different homologues are compared for production, revealing 6.3- and 4.5-fold differences in β-amyrin and oleanolic acid productivities and varying CYP716A product profiles, which are important to consider when engineering strains for the production of bioactive oleanolic acid derivatives

EVALUATING THE USE OF CAMERA TRAPS TO MONITOR POPULATIONS OF UNGULATE PREY IN THE RUSSIAN FAR EAST

Efforts to recover endangered carnivore populations are often limited by insufficient populations of prey. When recovering prey populations, estimates of population density are invaluable metrics to monitor recovery efforts. In Russia, wildlife managers use the Formozov-Malyushev-Pereleshin (FMP) snow tracking method to estimate densities of ungulate prey of the Amur tiger (Panthera tigris). Yet, increasing variability in snow conditions and other challenges have limited its reliability. Camera traps offer a promising alternative approach since managers already use cameras to monitor tigers. However, the assumptions and study design necessary to implement capture-recapture models for tigers are different from those needed to implement models for unmarked populations of prey. In Chapter 1, I estimated densities of wild boar (Sus scrofa), red deer (Cervus canadensis ssp. xanthopygus), roe deer (Capreolus pygargus), and sika deer (Cervus nippon) using Random Encounter models (REM), Space-To-Event models (STE), and Time-To-Event models (TTE), then compared these with FMP estimates within Sikhote-Alin Biosphere Zapovednik. Estimates from the STE and FMP were the most similar, though there were challenges implementing the STE to data from motion-trigger cameras. All models detected a \u3e90% decline in wild boar density due to African Swine Fever. Simulations indicated that greater survey effort for all camera-based methods would be required to achieve a coefficient of variation of 20% (an objective set for this study area in 2006). This is likely cost-prohibitive for many conservation programs due to the high costs of randomly deploying many cameras. To examine the influence of study design on detections of ungulate prey, in Chapter 2 I compared relative abundance indices (RAIs) of prey using: (1) cameras placed on roads to monitor tigers; (2) cameras placed using systematic random sampling; and (3) “off-road” cameras placed 150 meters away from road cameras. Both road and off-road RAIs were greater than random RAIs, and our attempt to approximate representative sampling with off-road cameras ultimately did not work. These results highlight the importance of random sampling to meet the assumptions of unmarked estimators. Detection data of prey species from cameras placed for tiger monitoring should not be used to estimate true abundance of prey species using these models

Contribution of floodplain wetland pools to the ecological functioning of the Fitzroy River Estuary

Coastal wetlands function as links between terrestrial and marine ecosystems throughout the world. They have vibrant and diverse flora and fauna, and are crucial habitats for fish and invertebrates, often providing critical nursery grounds and are major contributors of nutrients to coastal systems. However, our present understanding of tropical and subtropical estuarine floodplain wetlands is limited, particularly in tropical and subtropical areas. This lack of understanding, together with their extensive ecological importance and their value to so many user groups, makes detailed understanding of estuarine floodplain wetlands an important research priority. The delta of the Fitzroy River, in Central Queensland, has extensive wetlands clustered around its large estuary system. Except during flooding, the aquatic environment of the wetlands is restricted to a number of semi-permanent pools of varying types and sizes, which are recognised as important nursery habitats for marine fish, such as barramundi. Unfortunately, the way these habitats provide for juvenile fish, and how juvenile fish interact with other animals and plants associated with the pools (as prey or predators) is unknown. Similarly, there is no knowledge of how aquatic animals are influenced by the type of pool environment (eg. marine or freshwater influenced), or how the compositions and fates of pool inhabitants are influenced by the degree and regularity of connection to other habitats. Thus the current project aims to extend, broaden and refine our understanding by investigating the in luence of connectivity on faunal dynamics and food webs of Fitzroy Estuarine Floodplain Wetland Pools. The current study was conducted during a drought period, with no substantial wet season flows during the project. This has two consequences: (1) the study is limited to wetland pools, with little ability to generalise the results to the whole wetland, and (2) the results of the study are not necessarily representative of the situation during wet years

Space Plasma Interactions with Spacecraft Materials

Spacecraft materials on orbit are subjected to the harsh weather of space. In particular, high-energy electrons alter the chemical structure of polymers and cause charge accumulation. Understanding the mechanisms of damage and charge dissipation is critical to spacecraft construction and operational anomaly resolution. Energetic particles in space plasma break molecular bonds in polymers and create radicals that can act as space charge traps. These electron-induced chemical changes also result in changes to the spectral absorption profile of polymers on orbit. Radicals react over time, either recreating identical bonds to those in the pristine material, leading to material recovery, or creating new bonds, resulting in a new material with new physical properties. Lack of knowledge about this dynamic aging is a major impediment to accurate modeling of spacecraft behavior over its mission life. This chapter first presents an investigation of the chemical and physical properties of polyimide films (PI, Kapton-H®) during and after irradiation with high-energy (90 keV) electrons. Second, the deleterious effects of space plasma on a spacecraft component level are presented. The results of this physical/chemical collaboration demonstrate the correlation of chemical changes in PI with the dynamic nature of spacecraft material aging

Sediment structure and physicochemical changes following tidal inundation at a large open coast managed realignment site

Managed realignment (MR) schemes are being implemented to compensate for the loss of intertidal saltmarsh habitats by breaching flood defences and inundating the formerly defended coastal hinterland. However, studies have shown that MR sites have lower biodiversity than anticipated, which has been linked with anoxia and poor drainage resulting from compaction and the collapse of sediment pore space caused by the site's former terrestrial land use. Despite this proposed link between biodiversity and soil structure, the evolution of the sediment sub-surface following site inundation has rarely been examined, particularly over the early stages of the terrestrial to marine or estuarine transition. This paper presents a novel combination of broad- and intensive-scale analysis of the sub-surface evolution of the Medmerry Managed Realignment Site (West Sussex, UK) in the three years following site inundation. Repeated broad-scale sediment physiochemical datasets are analysed to assess the early changes in the sediment subsurface and the preservation of the former terrestrial surface, comparing four locations of different former land uses. Additionally, for two of these locations, high-intensity 3D-computed X-ray microtomography and Itrax micro-X-ray fluorescence spectrometry analyses are presented. Results provide new data on differences in sediment properties and structure related to the former land use, indicating that increased agricultural activity leads to increased compaction and reduced porosity. The presence of anoxic conditions, indicative of poor hydrological connectivity between the terrestrial and post-inundation intertidal sediment facies, was only detected at one site. This site has experienced the highest rate of accretion over the terrestrial surface (ca. 7 cm over 36 months), suggesting that poor drainage is caused by the interaction (or lack of) between sediment facies rather than the former land use. This has significant implications for the design of future MR sites in terms of preparing sites, their anticipated evolution, and the delivery of ecosystem services

Why do Students Still Bother to Come to Lectures When Everything is Online?

With the recent emergence of an extensive range of online resources: everything from electronic lecture notes, slides, mp3 podcasts to the fully-downloadable recorded lecture with coordinated audio and visual images, the obvious question is: “Why do students still bother to come to lectures?” To explore this question, a preliminary survey was carried out within junior, intermediate and senior courses taught by School of Molecular Bioscience, The University of Sydney during second semester, 2009. This simple voluntary survey, which was mounted on WebCT, had two simple questions, each of which allowed both constrained and open responses. Do you attend lectures? How would you feel if there were no face-to-face lectures and lectures were only available online? Of those students who responded to the survey, the overwhelming majority, surprisingly, attended most lectures. For a voluntary on-line survey which was only accessible over a two-week period, the response rate was very encouraging. Most respondents also submitted abundant, enthusiastic free-form comments. The students were keen to give their opinion; many of the comments contained more than one reason for their attendance pattern. Because of this, the results (both numerical data and comments) provide a rich resource of student opinion for analysis. This conference provides the ideal opportunity to reflect on our data with assistance from a wider audience

Why do Students Still Bother Coming to Lectures, When Everything is Available Online?

Web-based lecture technologies (WBLTs), which deliver recorded lectures and notes online, are increasingly common. However, there is concern that they may reduce lecture attendance. Since we did not observe a significant drop in attendance following the introduction of WBLTs in the School of Molecular Bioscience at the University of Sydney, we surveyed 563 students to discover why they attended lectures despite the availability of copious online materials. 82 % of responding students reported they always or mostly attend lectures and 74% expressed a negative emotion when asked how they would feel if lectures were abolished. Free-form comments indicated that students attend lectures for reasons either positive about lectures or negative about WBLTs. Students feel that lectures provide a disciplined learning environment where they can concentrate in a scholarly community. Lectures intrinsically contribute to the ‘university experience’ and the social aspect is also important. Some students are motivated to attend through habit, guilt or by financial concerns. Negative comments highlighted perceptions that WBLTs do not fully capture lecture content, can be inefficient and unreliable, and predispose students to procrastination. The majority of students use WBLTs in addition to attending lectures and perceive distinct roles for each mode. Most students who did not attend lectures claimed they were unable to for logistical reasons, although some cited inconvenience, overcrowding or peer-distraction. Students also make strategic decisions to prioritise competing commitments. Only a minority of students prefer WBLTs to attendance. These students prefer the ability to work at a time, place and pace of their choosing. This study supports the contention that WBLTs alone do not reduce lecture attendance, and highlights features of lectures which can be improved to increase attendance and student engagement

Chapter 19: Vulnerability of coastal and estuarine habitats in the Great Barrier Reef to climate change

This chapter attempts to address the vulnerability of the CEM in the Great Barrier Reef region to global climate change. It does not consider individual habitats (eg reefs or seagrasses) but goes beyond the individual species and habitat assessments, to consider impacts on the whole coastal marine community complex, and the ecological processes that support its functioning.This is Chapter 19 of Climate change and the Great Barrier Reef: a vulnerability assessment. The entire book can be found at http://hdl.handle.net/11017/13