668 research outputs found

    SCHOOLING BEHAVIOUR OF SARDINE SARDINOPS SAGAX IN FALSE BAY, SOUTH AFRICA

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    The schooling behaviour of sardine Sardinops sagax in False Bay on the south coast of South Africa was studied in October 1995 using high-resolution sonar and a hull-mounted, echo-integration unit. School formation and disintegration were studied, and school shape, packing density, swimming behaviour and inter- and intra-school event rates were quantified. Mean fish density was 29.5 fish m-3 (SD 46 fish m-3), but it varied between schools by a factor of about 100 (from 2 to 233 fish m-3). Tracked schools moved at average speeds of 0.67–1.59 m s-3. Schools changed shape on average every 2.08 minutes, and underwent either splits or merges with other schools on average every 5 minutes. Relationships between the geometric dimensions and biomass of the schools were established.Afr. J. mar. Sci. 25: 185–19

    Ultralong Copper Phthalocyanine Nanowires with New Crystal Structure and Broad Optical Absorption

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    The development of molecular nanostructures plays a major role in emerging organic electronic applications, as it leads to improved performance and is compatible with our increasing need for miniaturisation. In particular, nanowires have been obtained from solution or vapour phase and have displayed high conductivity, or large interfacial areas in solar cells. In all cases however, the crystal structure remains as in films or bulk, and the exploitation of wires requires extensive post-growth manipulation as their orientations are random. Here we report copper phthalocyanine (CuPc) nanowires with diameters of 10-100 nm, high directionality and unprecedented aspect ratios. We demonstrate that they adopt a new crystal phase, designated eta-CuPc, where the molecules stack along the long axis. The resulting high electronic overlap along the centimetre length stacks achieved in our wires mediates antiferromagnetic couplings and broadens the optical absorption spectrum. The ability to fabricate ultralong, flexible metal phthalocyanine nanowires opens new possibilities for applications of these simple molecules

    Conceptualizing the adventure-sports coach

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    As a comparatively recent development, the adventure-sports coach struggles for a clear and distinct identity. The generic term ‘instructor’ no longer characterizes the role and function of this subgroup of outdoor professionals. Indeed, although the fields of adventure/outdoor education and leadership are comparatively well researched, the arrival of this ‘new kid on the block’ appears to challenge both the adventure-sports old guard and traditional views of sports coaching. In an attempt to offer clarity and stimulate debate, this paper attempts to conceptualize the adventure-sports coach in the context of the existing roles in the field and current motivations for activity in the outdoors. We identify issues that are specific to the adventure-sports coach while also recognizing those skills and competencies shared with other professionals, both in the adventure sports profession and traditional sports coaching fields. Based on this review, we offer a conceptual model which may be used to focus debate, stimulate research and, at a possible later stage, to underpin accreditation, training and professional development

    Planned Cesarean or planned vaginal delivery for twins : secondary analysis of randomized controlled trial

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    ACKNOWLEDGMENTS We thank all the participants in the Twin Birth Study and the staff at the Centre for Mother, Infant, and Child Research for their hard work and dedication. The Twin Birth Study was supported by a grant (63164) from the Canadian Institute of Health Research. P.T. and M.H.Z. were supported by a grant from The Netherlands Organization for Scientific Research (NWO ‐ grant number 401.16.080). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Habitual dietary nitrate intake and cognition in the Australian Imaging, Biomarkers and Lifestyle Study of ageing: A prospective cohort study

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    Background & aims Dietary nitrate improves cardiovascular health via a nitric oxide (NO) pathway. NO is key to both cardiovascular and brain health. There is also a strong association between vascular risk factors and brain health. Dietary nitrate intake could therefore be associated with better cognitive function and reduced risk of cognitive decline. This is yet to be investigated. The aim of this study was to investigate the association between habitual intake of dietary nitrate from sources where nitrate is naturally present, and cognitive function, and cognitive decline, in the presence or absence of the apolipoprotein E (APOE) ε4 allele. Methods The study included 1254 older adult participants of the Australian Imaging, Biomarkers and Lifestyle Study of Ageing who were cognitively normal at baseline. Plant-derived, vegetable-derived, animal derived nitrate (not including meat where nitrate is an allowed additive), and total nitrate intakes were calculated from baseline food frequency questionnaires using comprehensive nitrate databases. Cognition was assessed at baseline and every 18 months over a follow-up period of 126 months using a comprehensive neuropsychological test battery. Multivariable-adjusted linear mixed effect models were used to examine the association between baseline nitrate intake and cognition over the 126 months (median [IQR] follow-up time of 36 [18–72] months), stratified by APOE ε4 carrier status. Results In non APOE ε4 carriers, for every 60 mg/day higher intake of plant-derived nitrate at baseline there was an associated higher language score [β (95% CI): 0.10 (0.01, 0.19)] over 126 months, after multivariable adjustments. In APOE ε4 carriers, there was an associated better episodic recall memory [0.24 (0.08, 0.41)] and recognition memory [0.15 (0.01, 0.30)] scores. Similar associations were seen for the intakes of vegetable-derived and total nitrate. Additionally, in APOE ε4 carriers, for every 6 mg/day higher intake of animal-derived nitrate (excluding meat with nitrate as an allowed additive) at baseline there was an associated higher executive function score [β (95% CI): 1.41 (0.42, 2.39)]. We did not find any evidence of an association between dietary nitrate intake and rate of cognitive decline. Conclusion Our results suggest that habitual intake of dietary nitrate from sources where nitrate is naturally present impacts cognitive performance in an APOE genotype contingent manner. Further work is needed to validate our findings and understand potential mechanisms underlying the observed effects

    The association between Alzheimer's Disease-Related markers and physical activity in cognitively normal older adults

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    Previous studies have indicated that physical activity may be beneficial in reducing the risk for Alzheimer's disease (AD), although the underlying mechanisms are not fully understood. The goal of this study was to evaluate the relationship between habitual physical activity levels and brain amyloid deposition and AD-related blood biomarkers (i.e., measured using a novel high-performance mass spectrometry-based assay), in apolipoprotein E (APOE) ε4 carriers and noncarriers. We evaluated 143 cognitively normal older adults, all of whom had brain amyloid deposition assessed using positron emission tomography and had their physical activity levels measured using the International Physical Activity Questionnaire (IPAQ). We observed an inverse correlation between brain amyloidosis and plasma beta-amyloid (Aβ)1−42 but found no association between brain amyloid and plasma Aβ1−40 and amyloid precursor protein (APP)669−711. Additionally, higher levels of physical activity were associated with lower plasma Aβ1−40, Aβ1−42, and APP669−711 levels in APOE ε4 noncarriers. The ratios of Aβ1−40/Aβ1−42 and APP669−711/Aβ1−42, which have been associated with higher brain amyloidosis in previous studies, differed between APOE ε4 carriers and non-carriers. Taken together, these data indicate a complex relationship between physical activity and brain amyloid deposition and potential blood-based AD biomarkers in cognitively normal older adults. In addition, the role of APOE ε4 is still unclear, and more studies are necessary to bring further clarification

    Greed, recklessness and/or dishonesty? An investigation into the micro-regulation and culture of five UK banks between 2004-2009

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    The author uses a multiple case study approach to examine five UK banks in her paper. The banks are Northern Rock, the Royal Bank of Scotland, Barclays, Lloyds Banking Group and HSBC. The author feels that it is appropriate to use a multiple case study here because it will be interesting to study the micro aspects of regulation and corporate governance of five UK banks. The banks have to comply with the same regulations and laws on a macro level, so it is essential to examine the differences between these banks on a micro level through reviewing annual reports and financial ratios. The case study is longitudinal, spanning across 2004-2009. In accordance to the aims of a case study, the author will describe, understand and explain the effects of the financial crisis 2007 on five UK banks. This case study provides an opportunity to examine the weaknesses and failures of corporate governance of five UK banks at a micro level. The author has two hypotheses at the beginning of the study. First, banks moved from a customer driven culture to sales driven one. Secondly, the banking culture during between 2004-2009 is one of greed, recklessness and dishonesty. With the caveat that one should not make generalisations, there is evidence from the case study that both hypotheses are correct to a certain extent

    Adherence to a Mediterranean diet and Alzheimer's disease risk in an Australian population

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    The Mediterranean diet (MeDi), due to its correlation with a low morbidity and mortality for many chronic diseases, has been widely recognised as a healthy eating model. We aimed to investigate, in a cross-sectional study, the association between adherence to a MeDi and risk for Alzheimer's disease (AD) and mild cognitive impairment (MCI) in a large, elderly, Australian cohort. Subjects in the Australian Imaging, Biomarkers and Lifestyle Study of Ageing cohort (723 healthy controls (HC), 98 MCI and 149 AD participants) completed the Cancer Council of Victoria Food Frequency Questionnaire. Adherence to the MeDi (0- to 9-point scale with higher scores indicating higher adherence) was the main predictor of AD and MCI status in multinominal logistic regression models that were adjusted for cohort age, sex, country of birth, education, apolipoprotein E genotype, total caloric intake, current smoking status, body mass index, history of diabetes, hypertension, angina, heart attack and stroke. There was a significant difference in adherence to the MeDi between HC and AD subjects (P < 0.001), and in adherence between HC and MCI subjects (P < 0.05). MeDi is associated with change in Mini-Mental State Examination score over an 18-month time period (P < 0.05) in HCs. We conclude that in this Australian cohort, AD and MCI participants had a lower adherence to the MeDi than HC participants.S Gardener, Y Gu, S R Rainey-Smith, J B Keogh, P M Clifton, S L Mathieson, K Taddei, A Mondal, V K Ward, N Scarmeas, M Barnes, K A Ellis, R Head, C L Masters, D Ames, S L Macaulay, C C Rowe, C Szoeke and R N Martins for the AIBL Research Grou
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