Asymmetric adjustment in the City of London office market

Earlier estimates of the City of London office market are extended by considering a longer time series of data, covering two cycles, and by explicitly modeling of asymmetric space market responses to employment and supply shocks. A long run structural model linking real rental levels, office-based employment and the supply of office space is estimated and then rental adjustment processes are modeled using an error correction model framework. Rental adjustment is seen to be asymmetric, depending both on the direction of the supply and demand shocks and on the state of the space market at the time of the shock. Vacancy adjustment does not display asymmetries. There is also a supply adjustment equation. Two three-equation systems, one with symmetric rental adjustment and the other with asymmetric adjustment, are subjected to positive and negative shocks to employment. These illustrate differences in the two systems

Effect of HINS light on the contraction of fibroblast populated collagen lattices

High intensity narrow spectrum (HINS) light has been shown to have bactericidal effects on a range of medically important bacteria[1]. HINS technology could potentially be useful as a method for disinfecting medical implants, tissue engineered constructs and wounds. The fibroblast populated collagen lattice (FPCL) was used as an in vitro model to investigate the effect of HINS light on the wound contraction phase of wound healing

Impact of varying intensities of blue-light exposure on 3T3 cells

There is the need to develop a compatible sterilisation method for hybrid biomaterials. High-intensity blue light in the 405 nm region has been shown to be an effective bacterial decontamination method [1], to cause no noticeable damage to the gross structure of type-I collagen monomer (when treated at 10 mW/cm2) [2], and to have no noticeable effect on 3T3 cell viability, growth rate, redox state or lactate dehydrogenase (LDH) leakage (at 1.0 mW/cm2) [2]. The purpose of this research was to investigate the effect of varying the blue-light intensity on the 3T3 cell response parameters

Combined treatment of biomatrices with nisin and pulsed electric fields as a potential decontamination method?

Pulsed electric field (PEF) treatment has been shown to achieve bacterial inactivation in collagen gels whilst retaining the ability of the collagen to function as a biomaterial [1, 2]. Nisin, an antimicrobial peptide, has been used widely as a food preservative and has shown bactericidal action against a number of Gram-positive bacteria [3]. The potential of nisin to increase the efficacy of PEF disinfection of collagen gels to be used for tissue engineering applications was investigated

Radiation Hydrodynamics of Line-Driven Winds

Dimtri Mihalas' textbooks in the 70's and 80's on "Stellar Atmospheres" and "Foundations of Radiation Hydrodynamics" helped lay the early groundwork for understanding the moving atmospheres and winds of massive, luminous stars. Indeed, the central role of the momentum of stellar radiation in driving the mass outflow makes such massive-star winds key prototypes for radiation hydrodynamical processes. This paper reviews the dynamics of such radiative driving, building first upon the standard CAK model, and then discussing subtleties associated with the development and saturation of instabilities, and wind initiation near the sonic point base. An overall goal is to illuminate the rich physics of radiative driving and the challenges that lie ahead in developing dynamical models that can explain the broad scaling of mass loss rate and flow speed with stellar properties, as well as the often complex structure and variability observed in massive-star outflows.Comment: 14 pages. to appear in "Recent Directions in Astrophysical Quantitative Spectroscopy and Radiation Hydrodynamics

Studies on the pathology and treatment of equine navicular disease

This present study arose following the hypothesis that vascular occlusion and progressive ischaemia were involved in the pathogenesis of navicular disease. The study was designed so that an evaluation of the radiographic and pathological changes in the navicular bones and surrounding structures could be carried out in horses in which a clinical diagnosis of navicular disease had been made and these compared with the results of similar examinations in control horses with no evidence of lameness. Using clinical criteria combined with an objective method of assessment based on radiographic findings, the effects of different treatments of navicular disease were examined with particular emphasis on oral warfarin therapy. Of the 265 horses examined clinically, 90 constituted a control population, 151 had a lameness which was diagnosed as navicular disease and the remaining 24 horses, although they displayed a fore foot lameness similar to navicular disease, it fulfilled less than half the required clinical criteria and they were thus designated "not yet diagnosed" NYD. No one clinical feature was diagnostic of navicular disease in itself but it was concluded that the clinical diagnosis should be based on the presence of a number of clinical signs, and the response to a number of diagnostic aids. It is considered from this study that the particular type of work performed by a horse does not in itself predispose the animal to navicular disease but that irregular work, and sudden or prolonged periods of rest in an otherwise hard worked horse are predisposing factors. From radiographic examinations of the navicular bones of the horses in this study, no particular radiographic feature was considered to be diagnostic of navicular disease. The significant radiographic changes in the navicular bone in navicular disease were, an increase in number and change in shape and distribution of the distal nutrient foramina, the presence of nutrient foramina in the proximal border and radiolucent areas in the body of the bone. Some of these radiographic changes were found in the navicular bones of the control horses. The distal nutrient foramina were identified and classified according to their morphology and position and 7 basic types were found. Distal nutrient foramina, shaped other than conical were considered as abnormal. Examination of serial radiographs at intervals showed that the distal nutrient foramina could increase in number and show changes in their shape which were part of a progressive series of changes. An objective method of assessing radiographs of the navicular bone was developed which consisted of a scoring system based on the number shape and anatomical position of the distal nutrient foramina. Significantly higher scores per navicular bone were found in the navicular disease group than in the control group, although there was a degree of overlap between the groups. It is considered that this navicular scoring system provides a useful method of evaluating radiographs of the navicular bone, but should not be used as the sole criterion in the diagnosis of navicular disease. Pathological examination, which included gross pathology, radiography, microangiography, fluorescent microscopy following the administration of intra-vital fluorochrome bone labels to a number of horses, and light microscopy, showed that pathological changes were present in all of the navicular bones and deep flexor tendons in the navicular disease cases, and also in a small number of control cases. These pathological changes were present to different degrees and could be fitted into a pattern of increasing severity. The main pathological changes found in the navicular bone were, degeneration of the fiborcartilage, disruption and loss of the subchondral bone plate of the fibrocartilage surface, an overall increase in the vascularisation, remodelling or the trabeculae in the medulla, and in the deep flexor tendon there was disruption of tendon fibres. A significant positive correlation was found between the degree of gross pathological change present in the navicular bones and deep flexor tendons and the navicular score. No evidence of occlusive vascular disease or of bone necrosis was found in any of the navicular bones examined in this study. These- results do not therefore support the hypothesis that occlusive vascular disease and progessive ischaemia are involved in the pathogenesis of navicular disease. However, the overall increase in vascularisation and active bone remodelling, in the absence of obvious vascular occlusion and bone necrosis suggests that hyperaemia rather than ischaemia may be involved in the pathogenesis of this condition. Although the cause of the hyperaemia has not been established, there is evidence that active and/or passive hyperaemia could be involved. The treatments used in this study were, rest, oral warfarin therapy, corrective shoeing, phenylbutazone, neurectomy and isoxsuprine hydrochloride. The results of the treatments were assessed clinically and radiographically using the navicular scoring system. No significant difference was found between the results of the different treatments at 3-4, and 6-8 months from the start of treatments, but significantly better results were found with warfarin therapy, 1 year from the start of treatments. It is considered from the results of this study that the positive effects of warfarin and isoxsuprine hydrochloride in the treatment of navicular disease may not be related to the anticoagulant or vasodilator effects but may be associated with their ability to reduce blood viscosity and thus improve blood flow

Validity of a contact mat and accelerometric system to assess countermovement jump from flight time

Countermovement jump (CMJ) height is an important parameter in physical performance. This study compared CMJ height measured using ChronoJump contact mat (CJ) and Myotest accelerometer (MT) systems with a force platform (FP). Thirty recreationally active adults (32.1 ± 10.4 years, 75.9 ± 12.0 kg, 173.2 ± 6.3 cm) completed a CMJ protocol where height was simultaneously recorded using the three systems. CJ and MT measures were strongly and significant correlated (r = 0.65, 0.66, respectively; p  0.05), yet MT-derived measures were significantly different from those obtained using the FP (p < 0.05). Systematic bias was observed between FP and the CJ and between FP and MT. This study demonstrates the validity of CJ and MT systems for the assessment of CMJ height. Systematic bias and between-device differences in measurement should be considered when interpreting and comparing data from these devices

Telecommunications and radio-metric support for a manned mission to Mars

Some general characteristics of the Deep Space Network are described and related to services needed by a manned mission to Mars. Specific details of the current Network capabilities and those planned for the near future may be found in the reference