(Table 1) Helium and Thorium 230 excess concentrations in sediment cores B18 and B25

At four sites in the central equatorial Pacific Ocean the flux of extraterrestrial 3He, determined using the excess 230Th profiling method, is 8 * 10**-13 cm**3 STP/cm**2/ka. This supply rate is constant to within 30%. At these same sites, however, the burial rate of 3He, determined using chronostratigraphic accumulation rates, varies by more than a factor of 3. The lowest burial rates, which occur north of the equator at 1°N, 139°W are lower than the global average rate of supply of extraterrestrial 3He by 20% and indicate that sediment winnowing may have occurred. The highest burial rates, which are recorded at the equator and at 2°S, are higher than the rate of supply of extraterrestrial 3He by 100%, and these provide evidence for sediment focusing. By analyzing several proxies measured in core PC72 sediments spanning the past 450 kyr we demonstrate that periods of maximum burial rates of 230Th, 3He, 10Be, Ti, and barite, with a maximum peak-to-trough amplitude of a factor of 6, take place systematically during glacial time. However, the ratio of any one proxy to another is constant to within 30% over the entire length of the records. Given that each proxy represents a different source (234U decay in seawater, interplanetary dust, upper atmosphere, continental dust, or upper ocean), our preferred interpretation for the covariation is that the climate-related changes in burial rates are driven by changes in sediment focusing.

The role of age and emotional valence in word recognition: an ex-Gaussian analysis

The aim of this work is to evaluate the roles of age and emotional valence in word recognition in terms of ex-Gaussian distribution components. In order to do that, a word recognition task was carried out with two age groups, in which emotional valence was manipulated. Older participants did not present a clear trend for reaction times. The younger participants showed significant statistical differences in negative words for target and distracting conditions. Addressing the ex-Gaussian tau parameter, often related to attentional demands in the literature, age-related differences in emotional valence seem not to have an effect for negative words. Focusing on emotional valence for each group, the younger participants only showed an effect on negative distracting words. The older participants showed an effect regarding negative and positive target words, and negative distracting words. This suggests that the attentional demand is higher for emotional words, in particular, for the older participants.

The morphological response of Emiliania huxleyi to seawater carbonate chemistry changes: an inter-strain comparison

Four strains of the coccolithophore Emiliania huxleyi (RCC1212, RCC1216, RCC1238, RCC1256) were grown in dilute batch culture at four CO2 levels ranging from ~200 µatm to ~1200 µatm. Coccolith morphology was analyzed based on scanning electron micrographs. Three of the four strains did not exhibit a change in morphology over the CO2 range tested. One strain (RCC1256) displayed an increase in the percentage of malformed coccoliths with increasing CO2 concentration. We conclude that the sensitivity of the coccolith-shaping machinery to carbonate chemistry changes is strain-specific. Although it has been shown before that carbonate chemistry related changes in growth- and calcification rate are strain-specific, there seems to be no consistent correlation between coccolith morphology and growth or calcification rate. We did not observe an increase in the percentage of incomplete coccoliths in RCC1256, indicating that the coccolith-shaping machinery per se is affected by acidification and not the signalling pathway that produces the stop-signal for coccolith growth.

Distribution of heavy minerals in sediment cores from the Laptev Sea continental margin and the central Arctic Ocean

Focussing on heavy-mineral associations in the Laptev-Sea continental margin area and the eastern Arctic Ocean, 129 surface sediment samples, two short and four long gravity cores have been studied. By means of the accessory components, heavy-mineral associations of surface sediment samples from the Laptev-See continental slope allowed the distinction into two different mineralogical provinces, each influenced by fluvial input of the Siberian river Systems. Transport pathways via sea ice from the shallow shelf areas into the Arctic Ocean up to the final ablation areas of the Fram Strait can be reconstructed by heavy-mineral data of surface sediments from the central Arctic Ocean. The shallow shelf of the Laptev Sea seems to be the most important source area for terrigenous material, as indicated by the abundant occurence of amphiboles and clinopyroxenes. Underneath the mixing Zone of the two dominating surface circulation Systems, the Beaufort- Gyre and Transpolar-Drift system, the imprint of the Amerasian shelf regions up to the Fram Strait is detectable because of a characteristical heavy-mineral association dominated by detrital carbonate and opaque minerals. Based On heavy-mineral characteristics of the potential circum-Arctic source areas, sea-ice drift, origin and distribution of ice-rafted material can be reconstructed during the past climatic cycles. Different factors controlling the transport of terrigenous material into the Arctic Ocean. The entrainment of particulate matter is triggered by the sea level, which flooded during highs and lows different regions resulting in the incorporation of sediment from different source areas into the sea ice. Additionally, the fluvial input even at low stands of sea level is responsible for the delivery of material of distinct sources for entrainment into the sea ice. Glacials and interglacials of climate cycles of the last 780 000 years left a characteristical signal in the central Arctic Ocean sediments caused by the ice- rafted material from different sources in the circum-Arctic regions and its change through time. Changes in the heavy-mineral association from an amphibole-dominated into a garnet-epidote-assemblage can be related to climate-related changes in source areas and directions of geostrophic winds, the dominating drive of the sea-ice drift. During Marine Isotope Stage (MIS) 6, the central Arctic Ocean is marked by an heavy-mineral signal, which occurs in recent sediments of the eastern Kara Sea. Its characteristics are high amounts of epidote, garnet and apatite. On the other hand, during the Same time interval a continuous record of Laptev Sea sediments is documented with high contents of amphiboles on the Lomonosov Ridge near the Laptev Sea continental slope. A nearly similar Pattern was detected in MIS 5 and 4. Small-scale glaciations in the Putorana-mountains and the Anabar-shield may have caused changes in the drainage area of the rivers and therefore a change in fluvial input. During MIS 3, the heavy-mineral association of central Arctic sediments show similar patterns than the Holocene mineral assemblage which consists of amphiboles, ortho- and clinopyroxenes with a Laptev Sea source. These minerals are indicating a stable Transpolar-Drift system similar to recent conditions. An extended influence of the Beaufort Gyre is only recognized, when sediment material from the Amerasian shelf areas reached the core location PS2757-718 during Termination Ib. Based On heavy-mineral data from Laptev-Sea continental slope Core PS2458-4 the paleo-sea-ice drift in the Laptev Sea during 14.000 years was reconstructed. During Holocene sea-level rise, the bathymetrically deeper parts of the Western shelf were flooded first. At the beginning of the Atlantic stage, nearly the entire shelf was marine influenced by fully marine conditions and the recent surface circulation was established.

Computer-based tools for assessing micro-longitudinal patterns of cognitive function in older adults

Patterns of cognitive change over micro-longitudinal timescales (i.e., ranging from hours to days) are associated with a wide range of age-related health and functional outcomes. However, practical issues with conducting high-frequency assessments make investigations of micro-longitudinal cognition costly and burdensome to run. One way of addressing this is to develop cognitive assessments that can be performed by older adults, in their own homes, without a researcher being present. Here, we address the question of whether reliable and valid cognitive data can be collected over micro-longitudinal timescales using unsupervised cognitive tests.In study 1, 48 older adults completed two touchscreen cognitive tests, on three occasions, in controlled conditions, alongside a battery of standard tests of cognitive functions. In study 2, 40 older adults completed the same two computerized tasks on multiple occasions, over three separate week-long periods, in their own homes, without a researcher present. Here, the tasks were incorporated into a wider touchscreen system (Novel Assessment of Nutrition and Ageing (NANA)) developed to assess multiple domains of health and behavior. Standard tests of cognitive function were also administered prior to participants using the NANA system.Performance on the two “NANA” cognitive tasks showed convergent validity with, and similar levels of reliability to, the standard cognitive battery in both studies. Completion and accuracy rates were also very high. These results show that reliable and valid cognitive data can be collected from older adults using unsupervised computerized tests, thus affording new opportunities for the investigation of cognitive function.

Age and gender differences in the relation between self-concept facets and self-esteem

This study tested whether the gender intensification hypothesis applies to relations between multiple domain-specific self-concept facets and self-esteem. This hypothesis predicts gender-stereotypic differences in these relations and assumes they intensify with age. Furthermore, knowledge about gender-related or age-related differences in self-concept-self-esteem relations might provide valuable knowledge for designing effective self-esteem enhancement interventions. We investigated grade and gender differences in the relations between domain-specific self-concept facets and self-esteem within a sample of 1958 German students in Grades 3 to 6. Results indicated no difference in the self-concept - self-esteem relations between the subsamples of third and fourth graders and fifth and sixth graders or between boys and girls. These relations also did not differ between boys and girls in the subsamples of third and fourth graders and fifth and sixth graders. These results suggest self-concept-self-esteem relations to be invariant across grade levels and gender and thus did not support the gender intensification hypothesis.

PROTEIN-TRIGGERED SUSTAINED DRUG RELEASE CONTROLLED BY APTAMERS BOUND TO OLIGOMER-CROSSLINKED ALGINATE

Sustained drug release systems provide many advantages over traditional delivery methods such as extending the time in which the drug is found to be within an effective concentration within the therapeutic window, which decreases the frequency of administration of the drug, and increases patient compliance. Research using polyacrylamide crosslinked by oligomers containing an aptamer sequence, has demonstrated a pulsatile release over 50 minutes triggered by a 2 mM target adenosine concentration. This thesis aims to build off this concept by designing a system that delivers in a sustained manner when triggered by micromolar target concentrations reflective of disease in vivo, using macromolecular targets. For example, the disease wet age related macular degeneration (wet AMD) is associated with increased concentrations of the protein vascular endothelial growth factor (VEGF-A) – a macromolecule. Patients with wet AMD would benefit from the implantation of devices or microspheres that release drugs in a sustained manner in response to local VEGF concentrations. In this thesis, we hypothesize that the protein lysozyme, used to demonstrate proof-of-concept, could trigger the increased release of drugs from oligomer-crosslinked alginate. The objectives are to (i) demonstrate sustained release from alginate, (ii) design oligomer crosslinked alginate that degrades in response to lysozyme, and then (iii) use these systems to control the release of FITC-dextran with and without lysozyme. A series of control experiments and analyses were used to optimize the crosslinking of alginate by annealed oligomers. The cumulative release of FITC-dextran (MW 20,000) from oligomer crosslinked alginate increased by 3.4 μg when lysozyme (3 μM) was introduced at 48 hours, as opposed to controls which released only 0.2 μg. FITC-loaded alginate microspheres coated by oligomer-crosslinked alginate released 15% more FITC-dextran over 120 hours when placed into 3 μM of lysozyme than without lysozyme. Controls of alginate crosslinked with PEG or control oligomers (without a lysozyme aptamer sequence) had no changes in release with lysozyme. The incorporation of a lysozyme aptamer onto oligomers used to crosslink alginate disks or alginate coatings on microspheres resulted in different diffusion and release of FITC-dextran into PBS with or without lysozyme. This approach could be adapted for the delivery of drugs to diseases with specific protein profiles such as wet AMD.

Estado nutricional y etapas de cambio comportamental frente a la actividad física niños y adolescentes de Bogotá, Colombia: Estudio FUPRECOL

Objetivo: El propósito del estudio fue relacionar la etapa en el cambio en el comportamiento frente a la actividad física y el estado nutricional en escolares entre 9 y 17 años de Bogotá- Colombia, pertenecientes al estudio FUPRECOL. Método: Se trata de un estudio transversal, en 6.606 niños y adolescentes entre 9 y 17 años, pertenecientes a 24 instituciones educativas, de Bogotá-Colombia. Se aplicó de manera auto-diligenciada el cuestionario de cambio de comportamiento en función a la intensión de realizar actividad física (CCC-Fuprecol) y se midió el peso y la estatura para determinar el estado nutricional con el índice de masa corporal (IMC). Resultados: El porcentaje de respuesta fue 94% y se consideraron válidos 6,606 registros, siendo 58.3 % (n=3.850) niñas con un promedio de edad de 12,7±2,3 años. En la población general, el 5,3 % de los escolares se encontraban en etapa de pre-contemplación, 31,8 % en contemplación, el 26,7 % en acción y el 36,2 % en etapa de mantenimiento. Al comparar la etapa de cambio con el estado nutricional por IMC, los escolares clasificados en obesidad mostraron mayor frecuencia de respuesta en la etapa de pre-contemplación, mientras que los escolares con peso saludable acusaron mayores porcentajes en la etapa de mantenimiento. Conclusión: En escolares de Bogotá, Colombia, se encontró una relación estadísticamente significativa entre a la intensión de realizar actividad con el estado nutricional medido con el IMC. Fomentar la promoción de la actividad física y monitorear el estado nutricional, deberá ser una prioridad en las agendas y políticas públicas dentro del ámbito escolar.

El videojuego League of legends y su efecto en memoria de trabajo visual y solución de problemas

El propósito de este estudio es medir los efectos que tiene el videojuego League of Legends en los procesos cognitivos de memoria de trabajo visual (MVT) y solución de problemas (SP). Para medir dichos efectos se implementó un diseño pre test-post con un grupo experimental y uno control, compuestos cada uno por siete participantes, en donde se evaluaron los procesos previamente mencionados utilizando los cubos de Corsi para MVT y las matrices del WAIS III para SP. Después de realizar los respectivos entrenamientos se encontraron resultados significativos en los diferentes momentos de aplicación. En el grupo experimental se encontraron diferencias en la variable dependiente SP, mientras que en el grupo control en MVT, pero no en la interacción entre grupos ni diferencias entre grupos, lo que sugiere un efecto de familiarización a la prueba.

In-vehicle technology functional requirements for older drivers

Older drivers represent the fastest growing segment of the road user population. Cognitive and physiological capabilities diminishes with ages. The design of future in-vehicle interfaces have to take into account older drivers' needs and capabilities. Older drivers have different capabilities which impact on their driving patterns and subsequently on road crash patterns. New in-vehicle technology could improve safety, comfort and maintain elderly people's mobility for longer. Existing research has focused on the ergonomic and Human Machine Interface (HMI) aspects of in-vehicle technology to assist the elderly. However there is a lack of comprehensive research on identifying the most relevant technology and associated functionalities that could improve older drivers' road safety. To identify future research priorities for older drivers, this paper presents: (i) a review of age related functional impairments, (ii) a brief description of some key characteristics of older driver crashes and (iii) a conceptualisation of the most relevant technology interventions based on traffic psychology theory and crash data.

Executive and organisational leadership development in universities : exploring key elements and perceptions

Organisational and leadership development is said to be one of the most challenging and important activities facing universities, particularly in the current environment of fast-paced change and accelerated age-related attrition. Succession leadership development being timely, the purpose of this study was to explore the nature of leadership development most suited to meeting the leadership and organisational development challenges for contemporary universities. A blend of literature-based and empirical research was undertaken. This resulted in seven papers submitted to internationally refereed journals; five papers published, one in press, and one under review. Six of these are sole authored papers and one is a co-authored paper. The papers identify some of the issues and challenges facing the tertiary sector. They shed light on factors influencing executive and organisational leadership development deriving from the literature review and from empirical research reporting the views of current university leaders. The papers and submission document herein include recommendations and suggested models informing executive and organisational leadership development in universities. The "Lantern" model - an Illuminated Model for Organisational Leadership Development - is a key original conceptual model framing the study.

Housing supply in Australia : the impact of the availability of development finance

Before the Global Financial Crisis many providers of finance had growth mandates and actively pursued development finance deals as a way of gaining higher returns on funds with regular capital turnover and re-investment possible. This was able to be achieved through high gearing and low presales in a strong market. As asset prices fell, loan covenants breached and memories of the 1990’s returned, banks rapidly adjusted their risk appetite via retraction of gearing and expansion of presale requirements. Early signs of loosening in bank credit policy are emerging, however parties seeking development finance are faced with a severely reduced number of institutions from which to source funding. The few institutions that are lending are filtering out only the best credit risks by way of constrictive credit conditions including: low loan to value ratios, the corresponding requirement to contribute high levels of equity, lack of support in non-prime locations and the requirement for only borrowers with well established track records. In this risk averse and capital constrained environment, the ability of developers to proceed with real estate developments is still being constrained by their inability to obtain project finance. This paper will examine the pre and post GFC development finance environment. It will identify the key lending criteria relevant to real estate development finance and will detail the related changes to credit policies over this period. The associated impact to real estate development projects will be presented, highlighting the significant constraint to supply that the inability to obtain finance poses.

Wellness in older adults

Understanding perception of wellness in older adults is a question to be understood against the backdrop of concerns about whether global ageing and the ‘bulge’ of ageing baby boomers will increase health care cost beyond what modern economies can deal with. Older adults who age in a healthy way and who take responsibility for their own health offer a positive alternative and change the perception that older adults are a burden on their society’s health system. The concept of successful ageing introduced by Rowe and Kahn (1987; 1997) suggested that older adults age successfully if they avoid disease and disability, maintain high cognitive and physical functioning and remain actively engaged with life. This concept, however, did not reflect older adults’ own perceptions of what constitutes successful ageing or how perceptions of wellness or health-related quality of life influenced the older adult’s understanding of his or her own health and ageing. A research project was designed to examine older adults’ perceptions of wellness in order to gain an understanding of the factors that influence perception of their own wellness. Specifically, the research wanted to explore two aspects: whether belonging to a unique organisation, in this instance a Returned Services Club, influenced perceptions of wellness; and whether there are significant gender differences for the perception of wellness. A mixed method project with two consecutive studies was designed to answer these questions: a quantitative survey of members of a Returned Services Club and of the surrounding community in Queensland, Australia, and a qualitative study conducting focus groups to explore findings of the survey. The results of the survey were used to determine the composition of the focus groups. The participants for the first study, (N=257), community living adults 65 years and older, were chosen from the membership role of a Returned Services Club or recruited by personal approach from the community surrounding the Services Club. Participants completed a survey that consisted of a perception of wellness instrument, a health-related quality of life instrument, and questions on morbidities, modifiable life style factors and demographics. Data analysis found that a number of individual factors influenced perception of wellness and health-related quality of life. Positive influences were independent mobility, exercise and gambling at non-hazardous levels, and negative influences were hearing loss, memory problems, chronic disease and being single. Membership of the Services Club did not contribute to perception of wellness beyond being a member of a social group. While there may have been an expectation that members of an organisation that is traditionally associated with high alcohol use and problematic gambling may have lower perceptions of wellness, this study suggested that the negative influences may have been counteracted by the positive effects of social interaction, thus having neither negative nor positive influences on perception of wellness. There were significant differences in perception of wellness and in health-related quality of life for women and men. The most significant difference was for women aged 85-90 who had significantly lower scores for perception of wellness than men or than any other age group. This result was the impetus for conducting focus groups with adults aged 85-90 years of age. Focus groups were conducted with 24 women and four men aged 85-90 to explore the survey findings for this age group. Results from the focus groups indicated that for older adults perception of wellness was a multidimensional construct of more complexity than indicated by the survey instrument. Elite older women (women over 85 years of age) related their perception of wellness to their ability to do what they wanted to do, and what they wanted to do significantly more than anything else, was to stay connected to family, friends and the community to which they belonged. From the focus group results it appeared that elite older women identified with the three elements of successful ageing – low incidence of disability and disease, high physical and cognitive functioning, and active engagement with life – but not in a flat structure. It appears that for elite older women good physical and mental health function to enable social connectedness. It is the elements of health that impact on the ability to do what they wanted to do that were identified as key factors: independent mobility, hearing and memory - factors that impact on the ability to interact socially. These elements were only identified when they impacted on the person’s ability to do what they wanted to do, for example mobility problems that were managed were not considered a problem. The study also revealed that older women use selection, optimisation and compensation to meet their goal of staying socially connected. The shopping centre was a key factor in this goal and older women used shopping centres to stay connected to the community and for exercise as well as shopping. Personal and public safety and other environmental concerns were viewed in the same context of enabling or disabling social connectedness. This suggested that for elite older women the model of successful ageing was hierarchical rather than flat, with social connectedness at the top, supported by cognitive functioning and good physical and mental health. In conclusion, this research revealed that perception of wellness in older adults is a complex, multidimensional construct. For older adults good health is related to social connectedness and is not a goal in itself. Health professionals and the community at large have a responsibility to take into account the ability of the older adult to stay socially connected to their community and to enable this, if the goal is to keep older adults healthy for as long as possible. Maintaining or improving perception of wellness in older adults will require a broad biopsychosocial approach that utilises findings such as older adults’ use of shopping centres for non-shopping purposes, concerns about personal and environmental safety and supporting older adults to maintain or improve their social connectedness to their communities.

Physiological investigation of periosteum structure and its application in periosteum tissue engineering

Although many different materials, techniques and methods, including artificial or engineered bone substitutes, have been used to repair various bone defects, the restoration of critical-sized bone defects caused by trauma, surgery or congenital malformation is still a great challenge to orthopedic surgeons. One important fact that has been neglected in the pursuit of resolutions for large bone defect healing is that most physiological bone defect healing needs the periosteum and stripping off the periosteum may result in non-union or non-healed bone defects. Periosteum plays very important roles not only in bone development but also in bone defect healing. The purpose of this project was to construct a functional periosteum in vitro using a single stem cell source and then test its ability to aid the repair of critical-sized bone defect in animal models. This project was designed with three separate but closely-linked parts which in the end led to four independent papers. The first part of this study investigated the structural and cellular features in periostea from diaphyseal and metaphyseal bone surfaces in rats of different ages or with osteoporosis. Histological and immunohistological methods were used in this part of the study. Results revealed that the structure and cell populations in periosteum are both age-related and site-specific. The diaphyseal periosteum showed age-related degeneration, whereas the metaphyseal periosteum is more destructive in older aged rats. The periosteum from osteoporotic bones differs from normal bones both in terms of structure and cell populations. This is especially evident in the cambial layer of the metaphyseal area. Bone resorption appears to be more active in the periosteum from osteoporotic bones, whereas bone formation activity is comparable between the osteoporotic and normal bone. The dysregulation of bone resorption and formation in the periosteum may also be the effect of the interaction between various neural pathways and the cell populations residing within it. One of the most important aspects in periosteum engineering is how to introduce new blood vessels into the engineered periosteum to help form vascularized bone tissues in bone defect areas. The second part of this study was designed to investigate the possibility of differentiating bone marrow stromal cells (BMSCs) into the endothelial cells and using them to construct vascularized periosteum. The endothelial cell differentiation of BMSCs was induced in pro-angiogenic media under both normoxia and CoCl2 (hypoxia-mimicking agent)-induced hypoxia conditions. The VEGF/PEDF expression pattern, endothelial cell specific marker expression, in vitro and in vivo vascularization ability of BMSCs cultured in different situations were assessed. Results revealed that BMSCs most likely cannot be differentiated into endothelial cells through the application of pro-angiogenic growth factors or by culturing under CoCl2-induced hypoxic conditions. However, they may be involved in angiogenesis as regulators under both normoxia and hypoxia conditions. Two major angiogenesis-related growth factors, VEGF (pro-angiogenic) and PEDF (anti-angiogenic) were found to have altered their expressions in accordance with the extracellular environment. BMSCs treated with the hypoxia-mimicking agent CoCl2 expressed more VEGF and less PEDF and enhanced the vascularization of subcutaneous implants in vivo. Based on the findings of the second part, the CoCl2 pre-treated BMSCs were used to construct periosteum, and the in vivo vascularization and osteogenesis of the constructed periosteum were assessed in the third part of this project. The findings of the third part revealed that BMSCs pre-treated with CoCl2 could enhance both ectopic and orthotopic osteogenesis of BMSCs-derived osteoblasts and vascularization at the early osteogenic stage, and the endothelial cells (HUVECs), which were used as positive control, were only capable of promoting osteogenesis after four-weeks. The subcutaneous area of the mouse is most likely inappropriate for assessing new bone formation on collagen scaffolds. This study demonstrated the potential application of CoCl2 pre-treated BMSCs in the tissue engineering not only for periosteum but also bone or other vascularized tissues. In summary, the structure and cell populations in periosteum are age-related, site-specific and closely linked with bone health status. BMSCs as a stem cell source for periosteum engineering are not endothelial cell progenitors but regulators, and CoCl2-treated BMSCs expressed more VEGF and less PEDF. These CoCl2-treated BMSCs enhanced both vascularization and osteogenesis in constructed periosteum transplanted in vivo.