36 research outputs found

    On Differential Structure for Projective Limits of Manifolds

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    We investigate the differential calculus defined by Ashtekar and Lewandowski on projective limits of manifolds by means of cylindrical smooth functions and compare it with the C^infty calculus proposed by Froehlicher and Kriegl in more general context. For products of connected manifolds, a Boman theorem is proved, showing the equivalence of the two calculi in this particular case. Several examples of projective limits of manifolds are discussed, arising in String Theory and in loop quantization of Gauge Theories.Comment: 38 pages, Latex 2e, to be published on J. Geom. Phys minor misprints corrected, reference adde

    A synthesis of three decades of socio-ecological change in False Bay, South Africa: setting the scene for multidisciplinary research and management

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    Over the past three decades, marine resource management has shifted conceptually from top-down sectoral approaches towards the more systems-oriented multi-stakeholder frameworks of integrated coastal management and ecosystem-based conservation. However, the successful implementation of such frameworks is commonly hindered by a lack of cross-disciplinary knowledge transfer, especially between natural and social sciences. This review represents a holistic synthesis of three decades of change in the oceanography, biology and human dimension of False Bay, South Africa. The productivity of marine life in this bay and its close vicinity to the steadily growing metropolis of Cape Town have led to its socio-economic significance throughout history. Considerable research has highlighted shifts driven by climate change, human population growth, serial overfishing, and coastal development. Upwelling-inducing winds have increased in the region, leading to cooling and likely to nutrient enrichment of the bay. Subsequently the distributions of key components of the marine ecosystem have shifted eastward, including kelp, rock lobsters, seabirds, pelagic fish, and several alien invasive species. Increasing sea level and exposure to storm surges contribute to coastal erosion of the sandy shorelines in the bay, causing losses in coastal infrastructure and posing risk to coastal developments. Since the 1980s, the human population of Cape Town has doubled, and with it pollution has amplified. Overfishing has led to drastic declines in the catches of numerous commercially and recreationally targeted fish, and illegal fishing is widespread. The tourism value of the bay contributes substantially to the country’s economy, and whale watching, shark-cage diving and water sports have become important sources of revenue. Compliance with fisheries and environmental regulations would benefit from a systems- oriented approach whereby coastal systems are managed holistically, embracing both social and ecological goals. In this context, we synthesize knowledge and provide recommendations for multidisciplinary research and monitoring to achieve a better balance between developmental and environmental agendas

    The economic well-being of nations is associated with positive daily situational experiences

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    People in economically advantaged nations tend to evaluate their life as more positive overall and report greater well-being than people in less advantaged nations. But how does positivity manifest in the daily life experiences of individuals around the world? The present study asked 15,244 college students from 62 nations, in 42 languages, to describe a situation they experienced the previous day using the Riverside Situational Q-sort (RSQ). Using expert ratings, the overall positivity of each situation was calculated for both nations and individuals. The positivity of the average situation in each nation was strongly related to the economic development of the nation as measured by the Human Development Index (HDI). For individuals’ daily experiences, the economic status of their nation also predicted the positivity of their experience, even more than their family socioeconomic status. Further analyses revealed the specific characteristics of the average situations for higher HDI nations that make their experiences more positive. Higher HDI was associated with situational experiences involving humor, socializing with others, and the potential to express emotions and fantasies. Lower HDI was associated with an increase in the presence of threats, blame, and hostility, as well as situational experiences consisting of family, religion, and money. Despite the increase in a few negative situational characteristics in lower HDI countries, the overall average experience still ranged from neutral to slightly positive, rather than negative, suggesting that greater HDI may not necessarily increase positive experiences but rather decrease negative experiences. The results illustrate how national economic status influences the lives of individuals even within a single instance of daily life, with large and powerful consequences when accumulated across individuals within each nation

    Aneurisma dell’aorta addominale sottorenale

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    The GSB total knee arthroplasty. A medium- and long-term follow-up and survival analysis.

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    Item does not contain fulltextFrom 1981 to 1987, 77 GSB-II total knee arthroplasties were implanted in 65 patients. There were 23 men and 42 women aged on average 60 years old (range 30-85 years). The diagnosis was osteoarthritis (OA) in 21 knees, rheumatoid arthritis (RA) in 44 knees, and other in 12 knees. A clinical and radiological follow-up was performed in two stages after a mean of 6.7 years (61 knees) and 14.8 years (22 knees) to assess the medium- and long-term results and to determine if deterioration had occurred after mid-term follow-up. A survival analysis was done with two endpoints: (1) revision, and (2) revision, moderate or severe pain and lost to follow-up (worst-case scenario). At the last follow-up 36 patients (44 knees) had died, 2 patients (2 knees) refused examination, and 3 patients (3 knees) were lost to follow-up. Six knees had been revised for malposition (1.3%), septic (3.9%) and aseptic (2.6%) loosening. The mean Knee Society score after 6.7 and 14.8 years was 85 points (OA 82 points, RA 87 points). Lateralisation, subluxation or dislocation of the patella was present in 8 of 17 knees at the last follow-up. The 6- and 15-year survival rates with revision as the endpoint were 95% (CI 89%-100%) and 87% (CI 65%-100%), respectively. For the worst-case scenario, the 6- and 15-year survival rates were 95% (CI 89%-100%) and 56% (CI 0%-100%), respectively. The medium- and long-term results of the GSB-II total knee arthroplasty were good, and a decline in the knee score did not occur beyond the mid-term follow-up. Patella complications were abundant, and a marked decrease in implant survival was noted when moderate or severe pain and lost to follow-up were included as endpoints

    Arteriovenous fistulae as an alternative to central venous catheters for delivery of long-term home parenteral nutrition.

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    Contains fulltext : 80217.pdf (publisher's version ) (Closed access)BACKGROUND & AIMS: The success of home parenteral nutrition (HPN) programs is compromised by complications of central venous catheters (CVCs), such as occlusions and bloodstream infections. We performed a retrospective analysis of complication rates of arteriovenous fistulae versus CVCs in patients on long-term HPN. METHODS: Data were collected from 127 consecutive patients who received HPN between January 2000 and October 2006, comprising 344 access years of CVCs and 194 access years of arteriovenous fistulae. We evaluated access-related bloodstream infection and occlusion incidence rates (number of complications per access year) using Poisson-normal regression analysis. Complication incidence rate ratios were calculated by dividing complication incidence rates of CVCs by those of arteriovenous fistulae, adjusting for HPN frequency, medication use, infusion fluid composition, and underlying diseases. RESULTS: Bloodstream infection incidence rates were 0.03/year for arteriovenous fistulae, 1.37/year for long-term CVCs (Port-a-Caths and tunneled catheters), and 3.12/year for short-term CVCs (nontunneled catheters). Occlusion incidence rates were 0.60/year for arteriovenous fistulae, 0.35/year for long-term CVCs, and 0.93/year for shortterm CVCs. Adjusted incidence rate ratios of long-term CVCs over arteriovenous fistulae were 47 (95% confidence interval, 19-117) for bloodstream infections and 0.53 (95% confidence interval, 0.31-0.89) for occlusions. CONCLUSIONS: The occlusion incidence rate was higher for arteriovenous fistulae than for certain types of CVCs. The incidence rate of the most serious access-related complication (bloodstream infections) was much lower for arteriovenous fistulae than for all types of CVCs. Thus, arteriovenous fistulae are safe and valuable alternatives to CVCs for patients requiring long-term HPN

    Pretoriana, no. 050 & 051, Apr & Aug 1966

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    Voorwoord = Preface / N.A. Coetzee -- Die republikeinse strewe in die geskiedenis van Suid-Afrika / F.J. du Toit Spies & M.C. van Zyl -- Kommandant-generaal A.H. Potgieter / Jan Ploeger -- Kommandant-generaal A.W.J. Pretorius / F.A. van Jaarsveld -- President J.P. Hoffman / Jan Ploeger -- President J.N. Boshof / F.J. du Toit Spies -- President J.H. Brand / M.C. van Schoor -- President F.W. Reitz / F.J. du Toit Spies -- President M.Y. Steyn / F.J. du Toit Spies -- Administrateur N.C. Gey van Pittius / W.J. de Kock -- President L.J. Meyer / Anoniem -- President S. Parker / W.S. Robertson -- Administrateur G.J. van Niekerk / W.J. de Kock -- President M.W. Pretorius / F.A. van Jaarsveld -- President W.C. Janse van Rensburg / H.M. Rex -- President T.F. Burgers / M.C. van Zyl -- President S.J.P. Kruger / J.I. Rademeyer -- Staatspresident C.R. Swar

    Differentiation of Mycobacterium tuberculosis complex by PCR amplification of genomic regions of difference

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    Differentiation of members of the Mycobacterium tuberculosis complex by conventional mycobacteriological methods is time consuming, making surveillance of species-specific disease difficult. A two-step, multiplex polymerase chain reaction (PCR) method based on genomic regions of difference (RD1, RD1 mic, RD2seal, RD4, RD9 and RD12) was developed for the differentiation of M. canettii, M. tuberculosis, M. africanum, M. microti, M. pinnipedii, M. caprae, M. bovis and M. bovis BCG. The size of the respective multiplex PCR amplification products corresponded to the presence of the different M. tuberculosis complex members. This method allows for rapid differentiation, making it suitable for routine laboratories and surveillance purposes. © 2006 The Union.Articl

    Differentiation of Mycobacterium tuberculosis complex by PCR amplification of genomic regions of difference

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    Differentiation of members of the Mycobacterium tuberculosis complex by conventional mycobacteriological methods is time consuming, making surveillance of species-specific disease difficult. A two-step, multiplex polymerase chain reaction (PCR) method based on genomic regions of difference (RD1, RD1 mic, RD2seal, RD4, RD9 and RD12) was developed for the differentiation of M. canettii, M. tuberculosis, M. africanum, M. microti, M. pinnipedii, M. caprae, M. bovis and M. bovis BCG. The size of the respective multiplex PCR amplification products corresponded to the presence of the different M. tuberculosis complex members. This method allows for rapid differentiation, making it suitable for routine laboratories and surveillance purposes. © 2006 The Union.Articl
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