Influence of Tides and Mesoscale Eddies in the Ross Sea

The Ross Sea is the most biologically productive region in the Southern Ocean. Primary production is controlled by dissolved iron (dFe), a limiting micronutrient. The main focus of this thesis, motivated by the PRISM-RS project, is to investigate how tides and mesoscale eddies affect the pathways of dFe to the surface ocean. A regional ocean model with four hindcast simulations are used. Tidal forcing is added to simulations and mesoscale eddies are resolved by changing the horizontal grid resolution from 5 to 1.5 km. Simulations cover 1.5 years, ending at the time of the PRISM-RS cruise in early 2012. An extended 20 year simulation provides an estimate of model variability and significance. The model is validated using hydrographic data from the PRISM-RS cruise and climatological values of water mass volumes. Compared to observations, simulations show a salinity offset at depth, that can be attributed to freshening of the Ross Sea in recent years. The model represents water mass volumes well, but has a reduced amount of Ice Shelf Water. Analysis of eddy formation in the model indicates that the weak stratification produces small and short-lived mesoscale eddies in the Ross Sea. The increased resolution approximately doubles the number of eddies seen in one year of simulation and significantly increases the baroclinic eddy kinetic energy. The effect of tidal forcing on sea ice is investigated using a new method to extract a diurnal signal from satellite swath data. In the northwest corner of the Ross Sea continental shelf, strong tidal divergence causes the sea ice to decrease by 20% in winter. Simulation results show a strong heat flux that generates sea ice during spring tide conditions. The supply of dFe in simulations is calculated using four passive tracer dyes representing sources of dFe: sea ice, glacial ice, Circumpolar Deep Water, and benthic supply. The simulation without tides at 5 km resolution estimates the total supply of dFe to the surface at 6.63 μmol m-2 yr-1. Tides increase this by 20%, eddies decrease it by 15%, and the net change from both is not significant. Spatially, the pattern of dFe supply varies significantly between all simulations

Biosorption of precious metals from synthetic and refinery wastewaters by immobilized saccharomyces cerevisiae

The process of precious metal refining can be up to 99.99% efficient at best, and although it may seem small, the amount of valuable metal lost to waste streams is appreciable enough to warrant recovery. The method currently used to remove entrained metal ions from refinery wastewaters, chemical precipitation, is not an effective means for selective recovery of precious metals from a wastewater. Biosorption, the ability of certain types of biomass to bind and concentrate metals from even very dilute aqueous solutions, may be an effective point-source metal recovery strategy. The yeast, Saccharomyces cerevisiae, has been found capable of sorbing numerous precious and base metals, and is a cheap and abundant source of biomass. As such, it represents a possible precious metal sorbent for application to refining wastewaters. In this investigation, S. cerevisiae biomass was immobilized, using polyethyleneimine and glutaraldehyde, to produce a suitable sorbent, which was found to be capable of high platinum uptake (150 to 170 mg/g) at low pH (< 2). The sorption mechanism was elucidated and found to be a chemical reaction, which made effective desorption impossible. The sorption process was investigated in a packed bed column conformation, the results of which showed that the diameter and height of the column require further optimization in order to attain the metal uptake values achieved in the batch studies. When applied to a refinery wastewater, two key wastewater characteristics limited the success of the sorption process; the high inorganic ion content and the complex speciation of the platinum ions. The results proved the concept principle of platinum recovery by immobilized yeast biosorption and indicated that a more detailed understanding of the platinum speciation within the wastewater is required before the biosorption process can be applied. Overall, the sorption of platinum by the S. cerevisiae sorbent was demonstrated to be highly effective in principle, but the complexity of the wastewater requires that pretreatment steps be taken before the successful application of this process to an industrial wastewater

DEPOSITION OF ORGANIC THIN FILMS USING ENERGY TUNABLE MOLECULAR BEAMS ON SILICON DIOXIDE AND OCTADECYLTRICHLOROSILANE MODIFIED SILICON DIOXIDE

Organic semiconductors, in particular organic thin-film transistors (OTFTs), have been gaining recognition and spurring development in the electronics world now for more than a decade. The use of organic semiconductors is playing an ever increasing role in today?s industrial research in an effort to fill niches in technology left behind by traditional semiconductors such as silicon. The vast majority of research leading this outreach has been limited to the capabilities of thermally evaporated deposition techniques. A more advanced approach to investigating the underlying growth mechanics of organic semiconductors employs the use of a tunable molecular beam. Through controlling the expansive parameters of a molecular gas, a supersonic beam for molecular deposition can be created with strict control over the incident kinetic energy. This supersonic beam technique was employed to study the growth characteristics of pentacene and how they pertain to the electrical properties of an organic semiconducting device. At a constant growth rate, films were deposited at three incident kinetic energies (1.5 eV, 2.7 eV, 4.5 eV, and 6.7 eV) and analyzed using ellipsometry and atomic force microscopy. Growth characteristics of the film (roughening exponent ?, growth exponent ?, and the correlation length) were then extracted. Finally, surface modification of the dielectric with the self-assembled monolayer (SAM) octadecyltrichlorosilane (OTS) was used to influence the nucleation and growth parameters of the pentacene film. These parameters were studied as a function of the incident kinetic energy and electrical properties that resulted

Virtual Teams In Higher Education: The Light And Dark Side

Students and faculty are grappling with learning teams in the online environment - more than half of all higher education organizations offer online courses (Hoffman, 2006). As online course developers try to replicate the best practices of traditional classrooms, the asynchronous technology of the Internet has added great capability while also increasing the confusion that distance in space and time can add to the learning process. This study conducted a qualitative survey of online learning teams using content analysis by three researchers and grounded theory by the fourth researcher. Analysis of the rich text responses prompted the researchers to propose a model for online team development that reflected the functionality or dysfunctionality of teams. Key influences related to the internal or external locus of control of conscientious students. Key findings include strong connections between conscientiousness and attitude towards teamwork on the input side with satisfaction and trust for outcomes. Unlike other research, these online teams linked performance not to pedagogy, but conscientiousness, attitude towards teamwork, and trust. Technology did not hinder performance, suggesting that the new generation of learners is more comfortable with online interactions. The study detected a new factor, team leadership, as a core issue limiting learning and success within teams

Phillipp Fisch 4: Hitzefrei

In der Schule wird Hitzefrei gegeben, und Phillipp Fisch und seine Freunde fragen sich, warum es in der Ostsee jetzt öfter mal so heiß ist. Bei ihren Nachforschungen erfahren sie Einiges über den Klimawandel. Viele Kinder freuen sich, wenn in der Schule wegen „Hitzefrei“ früher Schluss ist. Auch Phillipp und seine Klasse jubeln, aber nur, bis sie herausfinden, dass es gar nicht gut ist, wenn das immer häufiger passiert... Naturwissenschaft leicht gemacht! Diese Geschichte erklärt Kindern spielerisch, wie sich die Ostsee durch den Klimawandel verändert und welchen Einfluss das auf die Lebewesen dort hat

An altered spatiotemporal gait adjustment during a virtual obstacle crossing task in patients with diabetic peripheral neuropathy

This study investigates spatiotemporal gait adjustments that occur while stepping over virtual obstacles during treadmill walking in people with/without diabetic peripheral neuropathy (DPN). Eleven adults with Type 2 diabetes mellitus, ten DPN, and 11 age-matched healthy adults (HTY) participated in this study. They stepped over forthcoming virtual obstacles during treadmill walking. Outcomes such as success rate, spatiotemporal gait characteristics during obstacle crossing, and correlations between these variables were evaluated. The results partially supported our hypotheses that when comparing with HTY and DM, people with DPN adopted a crossing strategy which decreased obstacle crossing success rate and maximal toe elevation, and increased stride time and stance time during virtual obstacle crossing. This might be due to the compromised somatosensory functions of their lower extremity which may increase the risk of falling. This study also found an inter-leg relationship which may be applied to future stepping or obstacle crossing training that incorporates both legs as a means for improving outcomes of the trailing leg during daily obstacle negotiation

Object Relations in the Museum: A Psychosocial Perspective

This article theorises museum engagement from a psychosocial perspective. With the aid of selected concepts from object relations theory, it explains how the museum visitor can establish a personal relation to museum objects, making use of them as an ‘aesthetic third’ to symbolise experience. Since such objects are at the same time cultural resources, interacting with them helps the individual to feel part of a shared culture. The article elaborates an example drawn from a research project that aimed to make museum collections available to people with physical and mental health problems. It draws on the work of the British psychoanalysts Donald Winnicott and Wilfred Bion to explain the salience of the concepts of object use, potential space, containment and reverie within a museum context. It also refers to the work of the contemporary psychoanalyst Christopher Bollas on how objects can become evocative for individuals both by virtue of their intrinsic qualities and by the way they are used to express personal idiom

Using patient-reported outcome measures to deliver enhanced supportive care to people with lung cancer : feasibility and acceptability of a nurse-led consultation model

Purpose: Developing new supportive/palliative care services for lung cancer should encompass effective ways to promptly identify and address patients’ healthcare needs. We examined whether an in-clinic, nurse-led consultation model, which was driven by use of a patient-reported outcomes (PRO) measure, was feasible and acceptable in the identification of unmet needs in patients with lung cancer. Methods: A two-part, repeated-measures, mixed-methods study was conducted. Part 1 employed literature reviews and stakeholder focus group interviews to inform selection of a population-appropriate needs assessment PRO measure. In Part 2, lung cancer nurse specialists (CNS) conducted three consecutive monthly consultations with patients. Recruitment/retention data, PRO data, and exit interview data were analysed. Results: The Sheffield Profile for Assessment and Referral to Care was the PRO measure selected based on Part 1 data. Twenty patients (response rate: 26%) participated in Part 2; 13 (65%) participated in all three consultations/assessments. The PRO measure helped patients to structure their thinking and prompted them to discuss previously underreported and/or sensitive issues, including such topics as family concerns, or death and dying. Lung CNS highlighted how PRO-measures-driven consultations differed from previous ones, in that their scope was broadened to allow nurses to offer personalised care. Small-to-moderate reductions in all domains of need were noted over time. Conclusions: Nurse-led PRO-measures-driven consultations are acceptable and conditionally feasible to holistically identify and effectively manage patient needs in modern lung cancer care. PRO data should be systematically collected and audited to assist in the provision of supportive care to people with lung cancer

The effectiveness of a sustained nurse home visiting intervention for Aboriginal infants compared with non-Aboriginal infants and with Aboriginal infants receiving usual child health care : a quasi-experimental trial : the Bulundidi Gudaga study

Background: In Australia there is commitment to developing interventions that will 'Close the Gap' between the health and welfare of Indigenous and non-Indigenous Australians and recognition that early childhood interventions offer the greatest potential for long term change. Nurse led sustained home visiting programs are considered an effective way to deliver a health and parenting service, however there is little international or Australian evidence that demonstrates the effectiveness of these programs for Aboriginal infants. This protocol describes the Bulundidi Gudaga Study, a quasi-experimental design, comparing three cohorts of families from the Macarthur region in south western Sydney to explore the effectiveness of the Maternal Early Childhood Sustained Home-visiting (MECSH) program for Aboriginal families. Methods: Mothers were recruited when booking into the local hospital for perinatal care and families are followed up until child is age 4 years. Participants are from three distinct cohorts: Aboriginal MECSH intervention cohort (Group A), Non-Aboriginal MECSH intervention cohort (Group B) and Aboriginal non-intervention cohort (Group C). Eligible mothers were those identified as at risk during the Safe Start assessment conducted by antenatal clinic midwives. Mothers in Group A were eligible if they were pregnant with an Aboriginal infant. Mothers in Group B were eligible if they were pregnant with a non-Aboriginal infant. Mothers in Group C are part of the Gudaga descriptive cohort study and were recruited between October 2005 and May 2007. The difference in duration of breastfeeding, child body mass index, and child development outcomes at 18 months and 4 years of age will be measured as primary outcomes. We will also evaluate the intervention effect on secondary measures including: child dental health; the way the program is received; patterns of child health and illness; patterns of maternal health, health knowledge and behaviours; family and environmental conditions; and service usage for mothers and families. Discussion: Involving local Aboriginal research and intervention staff and investing in established relationships between the research team and the local Aboriginal community is enabling this study to generate evidence regarding the effectiveness of interventions that are feasible to implement and sustainable in the context of Aboriginal communities and local service systems. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12616001721493 Registered 14 Dec 2016. Retrospectively registered