Biology and ecology of four catshark species in the southwestern Cape, South Africa

Bibliography : leaves 98-109.This is the first biological study of four endemic catshark species, Haploblepharus edwardsii, H. pictus, Poroderma africanum and P. pantherinum, from the southwestern Cape. Diets of two hundred and forty-one specimens were examined via stomach contents. Prey were sorted and identified to the lowest possible taxon. An Index of Relative Importance (IRI = %F(%N + % V) was used to determine the importance of prey items in the catsharks' diets

Managing knowledge workers' commitment in small construction professional firms

Construction professional services (CPS) rely heavily on knowledge workers as their main resources in delivering their services. One of the main concerns in managing these workers is the development and maintenance of organisational commitment. Smaller firms, with more informal human resource management systems and practices are more likely to face challenges in managing their knowledge workers’ commitment. Arguably, the intrinsic characteristics of the construction industry mean that this effort of managing knowledge workers’ commitment will require an appropriate management framework for its successful implementation. This research seeks to develop a framework for informing the management of knowledge workers in a way that fosters organisational commitment in small CPS firms. Interviews with the employers of small CPS firms were conducted to explore some of the important issues such as the strategies and challenges associated with effectively managing knowledge workers’ organisational commitment. The findings reveal that employers associate commitment with loyalty and high quality work. Many strategies are used to influence commitment such as performance-based compensation, close working relationship, training, employee involvement in decision making and two-way communication. Meanwhile, the provision of job security and career advancement were seen as the biggest challenges in managing knowledge workers’ commitment. Finally, we conclude with limitations and implications of the findings that provide directions for future research

Does physical activity change following hip and knee replacement? Matched case-control study evaluating Physical Activity Scale for the Elderly data from the Osteoarthritis Initiative

Objectives: To determine whether physical activity measured using the Physical Activity Scale for the Elderly (PASE), changes during the initial 24 months post-total hip (THR) or knee replacement (TKR), and how this compares to a matched non-arthroplasty cohort. Design: Case-controlled study analysis of a prospectively collected dataset. Setting: USA community-based. Participants: 116 people post-THR, 105 people post-TKR compared to 663 people who had not undergone THR or TKR, or had hip or knee osteoarthritis. Cohorts were age-, gender- and BMI-matched. Main outcome measures: Physical activity assessed using the 12-item PASE at 12 and 24 months post-operatively. Results: There was no significant difference in total PASE score between pre-operative to 12 months (mean: 136 vs. 135 points; p=0.86) or 24 months following THR (mean: 136 vs 132 points; p=0.95). Whilst there was no significant difference in total PASE score from pre-operative to 12 months post-TKR (126 vs. 121 points; p=0.93), by 24 months people following TKR reported significantly greater physical activity (126 vs. 142 points; p=0.04). There was no statistically significant difference in physical activity between the normative matched and THR (p≥0.14) or TKR (p≥0.06) cohorts at 12 or 24 months post-joint replacement. Conclusions: Physical activity is not appreciably different to pre-operative levels at 12 or 24 months post-THR, but was greater at 24 months following TKR. Health promotion strategies are needed to encourage greater physical activity participation following joint replacement, and particularly targeting those who undergo THR

Disorder-Induced Shift of Condensation Temperature for Dilute Trapped Bose Gases

We determine the leading shift of the Bose-Einstein condensation temperature for an ultracold dilute atomic gas in a harmonic trap due to weak disorder by treating both a Gaussian and a Lorentzian spatial correlation for the quenched disorder potential. Increasing the correlation length from values much smaller than the geometric mean of the trap scale and the mean particle distance to much larger values leads first to an increase of the positive shift to a maximum at this critical length scale and then to a decrease.Comment: Author information under http://www.theo-phys.uni-essen.de/tp/ags/pelster_di

Detector for imaging of explosions: present status and future prospects with higher energy X-rays

The detector for imaging of explosions (DIMEX) is in operation at the synchrotron radiation (SR) beam-line at VEPP-3 electron ring at Budker INP since 2002. DIMEX is based on one-coordinate gas ionization chamber filled with Xe-CO2(3:1) mixture at 7atm, and active Frisch-grid made of Gas Electron Multiplier (GEM). The detector has spatial resolution of ~0.2mm and dynamic range of ~100 that allows to realize the precision of signal measurement at a percent level. The frame rate can be tuned up to 8 MHz (125 ns per image) and up to 32 images can be stored in one shot. At present DIMEX is used with the X-ray beam from 2T wiggler that has ~20 keV average energy. Future possibility to install similar detector at the SR beam-line at VEPP-4 electron ring is discussed.Comment: 14 pages, 15 figures. Submitted to JINS

Principles for the design and operation of engineer-to-order supply chains in the construction sector

By integrating the approaches of Forrester and Burbidge [Forrester, J. W. 1961. Industrial Dynamics. Pegasus Communications; Burbidge, J. L. 1961. "The "New Approach" to Production." Production Engineer 40: 769-784], a set of five design principles have emerged which provide a foundation for sound supply chain design. The 'FORRIDGE' principles have since been shown to be a powerful guide for effective design of make-to-stock supply chains. However, some have questioned the applicability of generic supply chain thinking, arguing for a tailored approach. Hence, the goal here is to investigate how these principles should be adapted for engineer-to-order (ETO) industries, such as construction, capital goods and shipbuilding. The empirical elements draw on an extensive study of 12 suppliers and two large contractors in the construction industry. Supply chain tactics are identified for this range of companies, which are matched with real world problems, and linked with the FORRIDGE principles. This results in an additional 'Design for X' principle being proposed. The contributions made are the adaptation of established principles for the ETO sector, and the framework behind these principles

Atomic Bose and Anderson glasses in optical lattices

An ultra cold atomic Bose gas in an optical lattice is shown to provide an ideal system for the controlled analysis of disordered Bose lattice gases. This goal may be easily achieved under the current experimental conditions, by introducing a pseudo-random potential created by a second additional lattice or, alternatively, by placing a speckle pattern on the main lattice. We show that for a non commensurable filling factor, in the strong interaction limit, a controlled growing of the disorder drives a dynamical transition from superfluid to Bose-glass phase. Similarly, in the weak interaction limit, a dynamical transition from superfluid to Anderson-glass phase may be observed. In both regimes, we show that even very low-intensity disorder-inducing lasers cause large modifications of the superfluid fraction of the system.Comment: 4 pages, 3 figures. Minor changes. To appear in Phys. Rev. Lett. (2003

Alginate inhibits iron absorption from ferrous gluconate in a randomized controlled trial and reduces iron uptake into Caco-2 cells

Previous in vitro results indicated that alginate beads might be a useful vehicle for food iron fortification. A human study was undertaken to test the hypothesis that alginate enhances iron absorption. A randomised, single blinded, cross-over trial was carried out in which iron absorption was measured from serum iron appearance after a test meal. Overnight-fasted volunteers (n=15) were given a test meal of 200g cola-flavoured jelly plus 21 mg iron as ferrous gluconate, either in alginate beads mixed into the jelly or in a capsule. Iron absorption was lower from the alginate beads than from ferrous gluconate (8.5% and 12.6% respectively, p=0.003). Sub-group B (n=9) consumed the test meals together with 600 mg calcium to determine whether alginate modified the inhibitory effect of calcium. Calcium reduced iron absorption from ferrous gluconate by 51%, from 11.5% to 5.6% (p=0.014), and from alginate beads by 37%, from 8.3% to 5.2% (p=0.009). In vitro studies using Caco-2 cells were designed to explore the reasons for the difference between the previous in vitro findings and the human study; confirmed the inhibitory effect of alginate. Beads similar to those used in the human study were subjected to simulated gastrointestinal digestion, with and without cola jelly, and the digestate applied to Caco-2 cells. Both alginate and cola jelly significantly reduced iron uptake into the cells, by 34% (p=0.009) and 35% (p=0.003) respectively. The combination of cola jelly and calcium produced a very low ferritin response, 16.5% (p<0.001) of that observed with ferrous gluconate alone. The results of these studies demonstrate that alginate beads are not a useful delivery system for soluble salts of iron for the purpose of food fortification