Fishing for Understanding: A Mixed Logit Model of Freshwater Angler Preferences

Freshwater fisheries management requires knowledge of not only the resource but angler preferences and the extent to which preferences vary. This paper reports results from an internet-based stated preference survey of anglers in the North Canterbury region. Discrete choice models are used to investigate how the quality of fishery attributes impact anglers’ selection of fishing sites. The models reveal significant preference heterogeneity between anglers for particular fishing site attributes. Furthermore, anglers’ preference intensities for identical attributes vary between sites. Consequently, efficient allocation of resources entails spatial and social components.discrete choice analysis, latent class, mixed logit, angler heterogeneity, New Zealand recreational trout fisheries, Agricultural and Food Policy, Environmental Economics and Policy, Research Methods/ Statistical Methods,

FUNDAMENTAL AND INDUCED BIASES IN TECHNOLOGICAL CHANGE IN CENTRAL CANADIAN AGRICULTURE

A new procedure is developed to estimate innovation possibility frontiers and test for biases in technological change. Using data on four inputs (land, machinery, chemicals and labour) from central Canada (Ontario and Quebec) over the period 1926-1985, we find that the innovations possibilities frontier shifts neutrally over time. This is consistent with Ahmad's model of induced innovations, but is not consistent with de Janvry's application of Ahmad's model to the historical development of Argentine agriculture. Agricultural research in Canada has been conducted with the objective of developing cost minimizing technologies. Empirical support was found for this notion in the development of the innovation possibilities frontier.Innovation possibility frontier, technological change, Research and Development/Tech Change/Emerging Technologies,

Local Industrial Structures and Female Entrepreneurship in India

We analyze the spatial determinants of female entrepreneurship in India in the manufacturing and services sectors. We focus on the presence of incumbent female-owned businesses and their role in promoting higher subsequent female entrepreneurship relative to male entrepreneurship. We find evidence of agglomeration economies in both sectors, where higher female ownership among incumbent businesses within a district-industry predicts a greater share of subsequent entrepreneurs will be female. Moreover, higher female ownership of local businesses in related industries (e.g., those sharing similar labor needs, industries related via input-output markets) predict greater relative female entry rates even after controlling for the focal district-industry’s conditions. The core patterns hold when using local industrial conditions in 1994 to instrument for incumbent conditions in 2000-2005. The results highlight that the traits of business owners in incumbent industrial structures influence the types of entrepreneurs supported.

Spatial Determinants of Entrepreneurship in India

We analyze the spatial determinants of entrepreneurship in India in the manufacturing and services sectors. Among general district traits, quality of physical infrastructure and workforce education are the strongest predictors of entry, with labor laws and household banking quality also playing important roles. Looking at the district-industry level, we find extensive evidence of agglomeration economies among manufacturing industries. In particular, supportive incumbent industrial structures for input and output markets are strongly linked to higher establishment entry rates. We also find substantial evidence for the Chinitz effect where small local incumbent suppliers encourage entry. The importance of agglomeration economies for entry hold when considering changes in India's incumbent industry structures from 1989, determined before large-scale deregulation began, to 2005

Accurate 3D reconstruction of bony surfaces using ultrasonic synthetic aperture techniques for robotic knee arthroplasty

Robotically guided knee arthroplasty systems generally require an individualized, preoperative 3D model of the knee joint. This is typically measured using Computed Tomography (CT) which provides the required accuracy for preoperative surgical intervention planning. Ultrasound imaging presents an attractive alternative to CT, allowing for reductions in cost and the elimination of doses of ionizing radiation, whilst maintaining the accuracy of the 3D model reconstruction of the joint. Traditional phased array ultrasound imaging methods, however, are susceptible to poor resolution and signal to noise ratios (SNR). Alleviating these weaknesses by offering superior focusing power, synthetic aperture methods have been investigated extensively within ultrasonic non-destructive testing. Despite this, they have yet to be fully exploited in medical imaging. In this paper, the ability of a robotic deployed ultrasound imaging system based on synthetic aperture methods to accurately reconstruct bony surfaces is investigated. Employing the Total Focussing Method (TFM) and the Synthetic Aperture Focussing Technique (SAFT), two samples were imaged which were representative of the bones of the knee joint: a human-shaped, composite distal femur and a bovine distal femur. Data were captured using a 5MHz, 128 element 1D phased array, which was manipulated around the samples using a robotic positioning system. Three dimensional surface reconstructions were then produced and compared with reference models measured using a precision laser scanner. Mean errors of 0.82 mm and 0.88 mm were obtained for the composite and bovine samples, respectively, thus demonstrating the feasibility of the approach to deliver the sub-millimetre accuracy required for the application

Aspergillus fumigatus enhances elastase production in pseudomonas aeruginosaco-cultures

In the cystic fibrosis (CF) lung the presence of bacteria and fungi in the airways promotes an inflammatory response causing progressive lung damage, ultimately leading to high rates of morbidity and mortality. We hypothesized that polymicrobial interactions play an important role in promoting airway pathogenesis. We therefore examined the interplay between the most commonly isolated bacterial CF pathogen, Pseudomonas aeruginosa, and the most prevalent filamentous fungi, Aspergillus fumigatus, to test this. Co-culture experiments showed that in the presence of A. fumigatus the production of P. aeruginosa elastase was enhanced. This was confirmed by the presence of zones of clearance on Elastin-Congo Red (ECR) agar, which was identified as elastase by mass spectrometry. When P. aeruginosa were grown in a co-culture model with mature A. fumigatus biofilms, 60% of isolates produced significantly more elastase in the presence of the filamentous fungi than in its absence (P < .05). The expression of lasB also increased when P. aeruginosa isolates PA01 and PA14 were grown in co-culture with A. fumigatus. Supernatants from co-culture experiments were also significantly toxic to a human lung epithelial cell line (19–38% cell cytotoxicity) in comparison to supernatants from P. aeruginosa only cultures (P < .0001). Here we report that P. aeruginosa cytotoxic elastase is enhanced in the presence of the filamentous fungi A. fumigatus, suggesting that this may have a role to play in the damaging pathology associated with the lung tissue in this disease. This indicates that patients who have a co-colonisation with these two organisms may have a poorer prognosis

Modeling of the hydrogen Lyman lines in solar flares

The hydrogen Lyman lines (91.2 nm < λ < 121.6 nm) are significant contributors to the radiative losses of the solar chromosphere, and they are enhanced during flares. We have shown previously that the Lyman lines observed by the Extreme Ultraviolet Variability instrument onboard the Solar Dynamics Observatory exhibit Doppler motions equivalent to speeds on the order of 30 km s−1. However, contrary to expectations, both redshifts and blueshifts were present and no dominant flow direction was observed. To understand the formation of the Lyman lines, particularly their Doppler motions, we have used the radiative hydrodynamic code, RADYN, along with the radiative transfer code, RH, to simulate the evolution of the flaring chromosphere and the response of the Lyman lines during solar flares. We find that upflows in the simulated atmospheres lead to blueshifts in the line cores, which exhibit central reversals. We then model the effects of the instrument on the profiles, using the Extreme Ultraviolet Variability Experiment (EVE) instrument's properties. What may be interpreted as downflows (redshifted emission) in the lines, after they have been convolved with the instrumental line profile, may not necessarily correspond to actual downflows. Dynamic features in the atmosphere can introduce complex features in the line profiles that will not be detected by instruments with the spectral resolution of EVE, but which leave more of a signature at the resolution of the Spectral Investigation of the Coronal Environment instrument onboard the Solar Orbiter

Local Industrial Structures and Female Entrepreneurship in India

We analyze the spatial determinants of female entrepreneurship in India in the manufacturing and services sectors. We focus on the presence of incumbent female-owned businesses and their role in promoting higher subsequent female entrepreneurship relative to male entrepreneurship. We find evidence of agglomeration economies in both sectors, where higher female ownership among incumbent businesses within a district-industry predicts a greater share of subsequent entrepreneurs will be female. Moreover, higher female ownership of local businesses in related industries (e.g., those sharing similar labor needs, industries related via input-output markets) predict greater relative female entry rates even after controlling for the focal district-industry's conditions. The core patterns hold when using local industrial conditions in 1994 to instrument for incumbent conditions in 2000–2005. The results highlight that the traits of business owners in incumbent industrial structures influence the types of entrepreneurs supported

Briefing: UK Ministry of Defence Force Protection Engineering Programme

The Defence Science and Technology Laboratory sponsored, QinetiQ-led Force Protection Engineering Research Programme has two main strands, applied and underpinning research. The underpinning strand is led by Blastech Ltd. One focus of this research is into the response of geomaterials to threat loading. The programme on locally won fill is split into four main characterisation strands: high-stress (GPa) static pressure–volume; medium-rate pressure–volume (split Hopkinson bar); high-rate (flyer plate) pressure–volume; and unifying modelling research at the University of Sheffield, which has focused on developing a high-quality dataset for locally won fill in low and medium strain rates. With the test apparatus at Sheffield well-controlled tests can be conducted at both high strain rate and pseudo-static rates up to stress levels of 1 GPa. The University of Cambridge has focused on using one-dimensional shock experiments to examine high-rate pressure–volume relationships. Both establishments are examining the effect of moisture content and starting density on emergent rate effects. Blastech Ltd has been undertaking carefully controlled fragment impact experiments, within the dataspace developed by the Universities of Sheffield and Cambridge. The data from experiments are unified by the QinetiQ-led modelling team, to predict material behaviour and to derive a scalable locally won fill model for use in any situation