bluuebunny/crossref_metadata_2025 huggingface dataset:
1.3 μm lasers with AlInAs-capped self-assembled quantum dots
Authors: Sellers I. R. , Liu H. Y. , Hopkinson M. , Mowbray D. J. , Skolnick M. S.
Published: December 2003

We report 1.3 μm room-temperature lasing for a self-assembled quantum dot (QD) laser in which the dots are capped by a thin AlInAs layer. The inclusion of the Al-containing layer is shown to improve the dot uniformity, and the larger carrier confinement increases the separation between the QD transitions. A RT threshold current density of 80 A cm−2 is obtained for a device containing three QD layers. The inclusion of the AlInAs layer allows the modification of the dot physical structure and electronic structure of the device, without any significant incorporation of nonradiative centers.
Fabrication and characterization of n-ZnO/p-AlGaN heterojunction light-emitting diodes on 6H-SiC substrates
Authors: Alivov Ya. I. , Kalinina E. V. , Cherenkov A. E. , Look D. C. , Ataev B. M. , Omaev A. K. , Chukichev M. V. , Bagnall D. M.
Published: December 2003

We report on the fabrication of n-ZnO/p-AlGaN heterojunction light-emitting diodes on 6H-SiC substrates. Hydride vapor phase epitaxy was used to grow p-type AlGaN, while chemical vapor deposition was used to produce the n-type ZnO layers. Diode-like, rectifying I–V characteristics, with threshold voltage ∼3.2 V and low reverse leakage current ∼10−7 A, are observed at room temperature. Intense ultraviolet emission with a peak wavelength near 389 nm is observed when the diode is forward biased; this emission is found to be stable at temperatures up to 500 K and shown to originate from recombination within the ZnO.
Piezoelectric effects on photoluminescence properties in 10-nm-thick InGaN quantum wells
Authors: Gotoh H. , Tawara T. , Kobayashi Y. , Kobayashi N. , Saitoh T.
Published: December 2003

We report a large change in the photoluminescence (PL) properties induced by piezoelectric effects found in 10-nm-thick InGaN quantum wells. The time-resolved PL properties are measured with changing excitation intensity at 17 K. A blueshift in the PL peak of 200 meV and a decrease in the PL decay time from 3 μs to 17 ns are found with increasing excitation intensity. This large change is caused by a strong internal electric field up to 1 MV/cm and a spatial separation between an electron and a hole of as much as three times the Bohr radius.
Extremely high current-limitation capability of underdoped YBa2Cu3O7−x superconductor
Authors: Mendoza E. , Puig T. , Granados X. , Obradors X. , Porcar L. , Bourgault D. , Tixador P.
Published: December 2003

A strategy has been envisaged leading to extremely high current-limitation capability of melt-textured, single-domain YBa2Cu3O7−x. Underdoped, single-domain, Bridgman-grown bars having an enhanced normal state resistivity allowed to generate extremely high electric fields during a current pulse (E≈4850 V/m), and maximum total energy density dissipated during a quench transition (e≈4×109 J/m3). We suggest that the enhanced performance for current limitation applications results from the combination of a strongly anisotropic electrical resistivity in the normal state due to the opening of a pseudogap and to the creation of impurity local density of states distributed at a nanometric scale in the superconducting chains, which then generate a dense array of hot spots.
White-electrophosphorescence devices based on rhenium complexes
Authors: Li Feng , Cheng Gang , Zhao Yi , Feng Jing , Liu Shiyong , Zhang Ming , Ma Yuguang , Shen Jiacong
Published: December 2003

Efficient white emission from the mixing of yellow emission from the Re-complexes, (4,4′-dimethyl-2,2′-bipyridine)Re(CO)3Cl (Dmbpy-Re), and blue emission from the N,N′-di-1-naphthyl-N, N′-diphenylbenzidine (NPB) is reported. NPB is used as the hole-transporting layer. 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline is used as the exciton-blocking as well as electron-transporting layer. Dmbpy-Re is doped into the host material (4,4′-N-N′-dicarbazole)biphenyl (CBP). The chromaticity of the white emission can be tuned by adjusting the thickness of Dmbpy-Re:CBP layer or the concentration of Dmbpy-Re in CBP. The maximum luminance, efficiency, and Commission Internationale De L’Eclairage coordinates at 9 V of the devices with 20-nm-thick and 30-nm-thick Dmbpy-Re:CBP layer at a fixed Dmbpy-Re doping concentration of 2 wt % in CBP are 1332 cd/m2, 2.9 cd/A, and (0.30,0.37), and 2410 cd/m2, 5.1 cd/A, and (0.36,0.43), respectively. The turn-on voltage of these devices is ∼4 V.
Exploring the Opsin shift with ab initio methods: Geometry and counterion effects on the electronic spectrum of retinal
Authors: Schreiber Marko , Buß Volker , Sugihara Minoru
Published: December 2003

To study the effect of the charged chromophore environment on the absorption spectrum of rhodopsin, we have calculated excited state energies of chromophore models using multi-configurational second-order perturbation theory. Taking advantage of the recently solved crystal structures of rhodopsin we have considered different chromophore geometries and their interaction with the Glu113 counterion, water and Glu181 in different protonation states. We observe a strongly blueshifted S1 state upon inclusion of Glu113/water to the wave function; the effect of the additional carboxyl group appears to be overbalanced by the complex counterion.
Nanofluidic channels with elliptical cross sections formed using a nonlithographic process
Authors: Czaplewski David A. , Kameoka Jun , Mathers Robert , Coates Geoffrey W. , Craighead H. G.
Published: December 2003

We fabricated nanofluidic channels that have elliptical cross sections with major and minor radii of less than 100 nm, without the use of electron-beam or other high-resolution lithography. The channels were formed by thermal removal of sacrificial polymer nanofibers. The sacrificial template fiber was deposited on a target substrate by electrospinning and encapsulated by a spin-on glass. The elliptical shape of the channels eliminates sharp corners, at which fluid flow is hindered, and provides convenient boundary conditions for theoretical modeling of fluid flow in the channels. Also, the spin-on glass is optically transparent and compatible with chemical analysis, thereby opening up application in biomolecular separation and single molecule analysis. Hundreds of parallel channels have also been formed by the oriented spinning process.
Microcantilevers integrated with heaters and piezoelectric detectors for nano data-storage application
Authors: Lee Caroline Sunyong , Nam Hyo-Jin , Kim Young-Sik , Jin Won-Hyeog , Cho Seong-Moon , Bu Jong-uk
Published: December 2003

A thermomechanical writing system and a piezoelectric readback system have been demonstrated using silicon cantilevers integrated with heaters and piezoelectric sensors for a low-power scanning-probe-microscopy data-storage system. A thin polymethylmethacrylate film has been used as a media to record data bits of 50 nm in diameter and 25 nm in depth using the silicon cantilever. The sensitivity of 0.22 fC/nm was also obtained using the fabricated cantilever. Finally, to obtain readback signals using the piezoelectric cantilever, a patterned oxide wafer with 30 nm depth was scanned to show the distinctive charge signals.
Ge dots self-assembling: Surfactant mediated growth of Ge on SiGe (118) stress-induced kinetic instabilities
Authors: Berbezier I. , Ronda A. , Portavoce A. , Motta N.
Published: December 2003

The ordering of islands on naturally or artificially nanostructured surfaces is one of the most recent objectives among actual nanotechnology challenges. We show in this letter that, by a combination of two approaches, i.e., a two-step molecular beam epitaxy (MBE) deposition process and surfactant-mediated growth, we are able to obtain chains of nicely ordered ultrasmall islands of lateral size below 50 nm. The two-step MBE process consists of vicinal Si(001) surface self-patterning by SiGe growth instability and Ge dot ordering by subsequent Ge deposition on a SiGe template layer. The surfactant-mediated growth consists of submonolayer Sb deposition prior to Ge growth, in order to reduce the island size up to 25 nm. The best ordering of Ge islands is obtained when the island size matches the wavelength of the template layer.
4.5 mW operation of AlGaN-based 267 nm deep-ultraviolet light-emitting diodes
Authors: Yasan A. , McClintock R. , Mayes K. , Shiell D. , Gautero L. , Darvish S. R. , Kung P. , Razeghi M.
Published: December 2003

We demonstrate 4.5 mW output power from AlGaN-based single quantum well ultraviolet light-emitting diodes at a very short wavelength of 267 nm in pulsed operation mode. The output power in continuous-wave mode reaches a value of 165 μW at an injected current of 435 mA. The measurements were done on arrays of four devices flip chip bonded to AlN submounts for thermal management.
Enhanced hydrolysis at monolayer MgO films
Authors: Savio L. , Celasco E. , Vattuone L. , Rocca M.
Published: December 2003

We report on a combined high resolution electron energy loss spectroscopy and x-rays photoelectron spectroscopy investigation of the interaction at room temperature of H2O with thin and ultra-thin MgO films grown on Ag(100). We find a strongly enhanced dissociation probability in the monolayer and sub-monolayer regime, indicative of an active role of the Ag substrate in the dissociation process. The active sites are suggested to be oxygen atoms with low coordination at the border of monolayer MgO islands.
What happens if we cannot fix it? Triage, palliative care and setting priorities in salinising landscapes
Authors: Hobbs Richard J. , Cramer Viki A. , Kristjanson Linda J.
Published: December 2003

It is increasingly recognised that rising saline water tables present an unprecedented threat to both agricultural production and biodiversity conservation in the agricultural areas of Australia. In Western Australia, hydrological analysis is increasingly indicating that treatment of the problem will be difficult and costly, perhaps even impossible in some cases. Given the limited resources available for conservation management, there is a need to prioritise efforts and ensure that the level and type of management applied is both appropriate and likely to be effective. We discuss options for this in terms of ideas borrowed from healthcare provision, including triage and palliative care. We examine the range of management responses available in salinising landscapes in relation to the degree of threat, the relative value of the remnant or landscape and the likelihood of successful management intervention. While we certainly need to make a concerted effort to limit damage and loss as far as is possible, we also have to face the possibility that we cannot do this effectively everywhere, and that some areas will not be treated or treatable.
Ecological risk to aquatic systems from salinity increases
Authors: Hart Barry T. , Lake P. S. , Webb J. Angus , Grace Michael R.
Published: December 2003

Salinity is a major problem in many regions of Australia, and is predicted to get considerably worse over the next 30–50 years. Most effort has focused on the terrestrial environment, and specifically on the loss of productive agricultural land. Increased salinity can also result in unwanted changes to aquatic ecosystems in rivers, streams and particularly wetlands.This paper first reviews the importance of assessing risks from salinity increases in a catchment context, and then introduces a disturbance–response conceptual model to assist with the understanding of such situations. Two factors are shown to be particularly important in assessing which freshwater systems will be most susceptible to increases in salinity—the location of the systems in the landscape, and the current ecological condition of the system. The resilience of an ecosystem to salinity disturbances is shown to be a useful concept which with further knowledge may be incorporated into risk-assessment approaches.The development of a new ecological risk assessment approach for assessing risks to aquatic systems in the Goulburn–Broken catchment from increases in salinity over the medium (20 years) and long (100 years) term is reported. The risks to the biota in Hughes Creek, a tributary of the Goulburn River, are assessed by using a probabilistic approach. Current salinity levels in the creek present a low risk to the biota.Finally, the paper addresses the challenge of making the ecological risk assessment method more quantitative by discussing the following two key aspects: how to better quantify the linkages between the key stressors and the biotic components, and how to better handle uncertainties.
Towards 'clean and green' farming systems using group learning to implement Environmental Management Systems
Authors: Ridley Anna M. , Paramore Tim , Seymour Eloise
Published: December 2003

Australian farmers want to market products as 'clean and green'. Environmental Management Systems (EMS) can help farmers improve their performance and justify 'green claims'. We worked with 12 farm families in southern New South Wales to develop and implement EMS using group learning and report progress towards developing more environmentally acceptable farming systems through increased perenniality and active management of remnant vegetation. Early on in the 3-year project, farmers assessed their environmental performance through development of a self-assessment questionnaire. Some had strong skills in management of remnant vegetation, whereas others were stronger in agronomy. Environmental monitoring tools were developed and tested, enabling farmers to assess on-farm perenniality, leakage (excess water lost) from paddocks and quality of remnant vegetation. Farmers became ready for the formal parts of EMS (environmental review, policy and action plans) half way through the project. The group-learning approach resulted in practice change. Improving farmers' understanding of environmental principles was found to be more important than the EMS process in achieving practice change, but EMS was a useful tool that enabled integration of production and environmental management.
Impacts of salinity on biodiversity—clear understanding or muddy confusion?
Authors: Briggs Sue V. , Taws Nicki
Published: December 2003

Dryland salinity has been known for several decades in eastern Australia. Its causes have been known for at least five decades. Why did it take so long for the problem to be officially recognised? Why is it taking so long for impacts of dryland salinity on terrestrial biodiversity to be investigated in eastern Australia? To answer these questions we delve back into human history and then move forwards to modern times. Historically, salt has connotations of punishment, money, status and love. Today, salt ignites powerful emotions in humans in modern institutions. Controlling the salinity agenda enhances status and provides resources. Impacts of salinity on biodiversity are often ignored when powerful groups with little interest in biodiversity compete for dominance of the salinity agenda. After discussing these factors, the paper presents information about impacts of dryland salinity on terrestrial biodiversity in eastern Australia. The limited research conducted shows that dryland salinity threatens vegetation communities that are already depleted from extensive clearing. Native ground species of plants in salinised woodlands are replaced by exotics and weeds. Trees die. The paper concludes with recommendations for future actions to enhance understanding and management of impacts of dryland salinity on terrestrial biodiversity in eastern Australia.
Effects of increasing salinity on freshwater ecosystems in Australia
Authors: Nielsen D. L , Brock M. A. , Rees G. N. , Baldwin D. S.
Published: December 2003

Salt is a natural component of the Australian landscape to which a number of biota inhabiting rivers and wetlands are adapted. Under natural flow conditions periods of low flow have resulted in the concentration of salts in wetlands and riverine pools. The organisms of these systems survive these salinities by tolerance or avoidance. Freshwater ecosystems in Australia are now becoming increasingly threatened by salinity because of rising saline groundwater and modification of the water regime reducing the frequency of high-flow (flushing) events, resulting in an accumulation of salt. Available data suggest that aquatic biota will be adversely affected as salinity exceeds 1000 mg L–1 (1500 EC) but there is limited information on how increasing salinity will affect the various life stages of the biota. Salinisation can lead to changes in the physical environment that will affect ecosystem processes. However, we know little about how salinity interacts with the way nutrients and carbon are processed within an ecosystem. This paper updates the knowledge base on how salinity affects the physical and biotic components of aquatic ecosystems and explores the needs for information on how structure and function of aquatic ecosystems change with increasing salinity.
Effect of salinity on small, ground-dwelling animals in the Western Australian wheatbelt
Authors: McKenzie N. L. , Burbidge A. H. , Rolfe J. K.
Published: December 2003

As part of a regional biodiversity survey, in total 304 quadrats, 1 ha each, were positioned to represent the diversity of physical environments across the geographical extent of the Western Australian wheatbelt. Uncleared sites variously affected/unaffected by salinity were chosen, but those showing overt changes caused by other types of disturbance were avoided as far as possible.Drift fences and pit traps were used to compile lists of the ground-dwelling spiders, scorpions, frogs, reptiles and mammals on the quadrats. For analysis, these data were compiled into a presence–absence matrix of species v. quadrat, and quadrats were assigned to various landform and salinity-'risk' classes.There was a negative relationship between the richness of small ground-dwelling animals and increasing salinity. Only lycosid spiders showed a positive relationship. A few vertebrates and spiders, particularly lycosids, are centred on saltflats. Another set of species occupies both the saltflats and the surrounding environments (woodlands) of dissection valley floors and lower slopes, while a much more diverse array of vertebrate and arachnid species is associated with these woodlands if they are not salt-affected. Woodland quadrats that are obviously affected by salinity support a subset of the species on their unaffected counterparts or on 'natural' saltflats.These empirical findings are consistent with predictions that, as soil salinity increases and the valley-floor woodland vegetations die, their faunas also contract. A few saltflat specialists colonise salt-affected sites along with the samphire shrublands.
What happens when you add salt: predicting impacts of secondary salinisation on shallow aquatic ecosystems by using an alternative-states model
Authors: Davis Jenny A. , McGuire Megan , Halse Stuart A. , Hamilton David , Horwitz Pierre , McComb Arthur J. , Froend Ray H. , Lyons Michael , Sim Lien
Published: December 2003

Alternative-states theory commonly applied, for aquatic systems, to shallow lakes that may be dominated alternately by macrophytes and phytoplankton, under clear-water and enriched conditions, respectively, has been used in this study as a basis to define different states that may occur with changes in wetland salinity. Many wetlands of the south-west of Western Australia are threatened by rapidly increasing levels of salinity as well as greater water depths and permanency of water regime. We identified contrasting aquatic vegetation states that were closely associated with different salinities. Salinisation results in the loss of freshwater species of submerged macrophytes and the dominance of a small number of more salt-tolerant species. With increasing salinity, these systems may undergo further change to microbial mat-dominated systems composed mostly of cyanobacteria and halophilic bacteria. The effect of other environmental influences in mediating switches of vegetation was also examined. Colour and turbidity may play important roles at low to intermediate salinities [concentration of total dissolved solids (TDS) <10 000 mg L–1]; however, coloured or turbid wetlands are rarely found at intermediate to high salinities (>10 000 mg L–1 TDS). The role of nutrients remains largely unquantified in saline systems. We propose that alternative-states theory provides the basis of a conceptual framework for predicting impacts on wetlands affected by secondary salinisation. The ability to recognise and predict a change in state with changes in salinity adds a further tool to decision-making processes. A change in state represents a fundamental change in ecosystem function and may be difficult to reverse. This information is also important for the development of restoration strategies. Further work is required to better understand the influence of temporal variation in salinity on vegetation states and probable hysteresis effects.
Effects of salinisation on riparian plant communities in experimental catchments on the Collie River, Western Australia
Authors: Lymbery A. J. , Doupé R. G. , Pettit N. E.
Published: December 2003

Although the salinisation of streams has long been recognised as one of Western Australia's most serious environmental and resource problems, there is very little published information on the effects of salinisation on riparian flora and fauna. We studied riparian vegetation in three experimental catchments on the Collie River in Western Australia. The catchments are situated within a 5-km area of state forest and are geologically and botanically similar, but differ in the extent of clearing, groundwater levels and stream salinity. In each catchment, transects were taken perpendicular to the direction of streamflow, and 4-m2 quadrats taken along each transect. Within each quadrat, soil salinity was measured, all plants were identified to species level and percentage cover estimated. The catchments differed significantly in soil salinity, with salinity being greatest in the most extensively cleared catchment and increasing towards the floor of the valley. Plant-species richness, species diversity and species composition were significantly related to soil salinity, both among catchments and among quadrats within the most extensively cleared catchment. Plant-species richness and diversity decreased with increasing soil salinity, an effect that may be partly due to a decline in perennial herb and shrub species. This may have an impact on other components of the riparian ecosystem.
Plastic flipper tags are inadequate for long-term identification of the flatback sea turtle (Natator depressus)
Authors: Parmenter C. J.
Published: December 2003

Two styles of plastic tags were used on flatback sea turtles (Natator depressus). In parallel with conventional metal flipper tagging, and internal PIT tagging methodologies, a total of 476 plastic tags were applied to 428 individual females in the 1991, 1992, 1993 and 1998 nesting seasons at Wild Duck Island, Queensland. Data are reported up to and including the 2000 nesting season demonstrating that plastic tags are inadequate for the long-term identification of these turtles, with failures of approximately 80% within three years of application.
Cutting the carnage: wildlife usage of road culverts in north-eastern New South Wales
Authors: Taylor Brendan D. , Goldingay Ross L.
Published: December 2003

Culverts have been used for a number of decades in Europe and the USA to reduce wildlife road-kills. In Australia, culverts have been employed by road authorities only relatively recently. This study used sand-strip surveys to investigate wildlife usage of nine purpose-built culverts along a 1.4-km section of the Pacific Highway at Brunswick Heads, north-east New South Wales. Surveys during two eight-day periods in spring and summer 2000 found 1202 traverses by wildlife through the culverts. Frequent culvert users were bandicoots (25% of traverses), rats (25%), wallabies (13%) and cane toads (14%). All culverts were used by these species, suggesting that at least several individuals of each species were involved. Infrequent users (each <2% of crossings) were possums, echidnas, lizards, birds and introduced carnivores. A koala was recorded crossing on two occasions. The long-nosed potoroo was observed in the surrounding habitat but was not confirmed traversing the culverts. Surveys for road-kills on this road section suggest that the exclusion fence bordering the highway prevented mammal road-kills and channeled mammals to the culverts. A single survey on a wet night found many frogs crossing the road surface and many were killed. This study confirms that culverts and exclusion fencing facilitate safe passage across a road for a range of wildlife species. This suggests that this form of management response to extensive road mortality of wildlife is appropriate and should be adopted more widely. However, this form of mitigation is not effective for frogs.
Assessing programs for monitoring threatened species - a tale of three honeyeaters (Meliphagidae)
Authors: Clarke Rohan H. , Oliver Damon L. , Boulton Rebecca L. , Cassey Phillip , Clarke Michael F.
Published: December 2003

We critically evaluated population-monitoring programs for three endangered species of Australian honeyeater: the helmeted honeyeater, Lichenostomus melanops cassidix, the black-eared miner, Manorina melanotis, and the regent honeyeater, Xanthomyza phrygia (Meliphagidae). Our results challenge the common assumption that meaningful monitoring is possible in all species within the five-year lifetime of recovery plans. We found that the precision achievable from monitoring programs not only depends on the monitoring technique applied but also on the species' biology. Relevant life-history attributes include a species' pattern of movement, its home-range size and its distribution. How well understood and predictable these attributes are will also influence monitoring precision. Our results highlight the large degree of variability in precision among monitoring programs and the value of applying power analysis before continuing longer-term studies. They also suggest that managers and funding agencies should be mindful that more easily monitored species should not receive preferential treatment over species that prove more difficult to monitor.
Use of burrows by the endangered pygmy blue-tongue lizard, Tiliqua adelaidensis (Scincidae)
Authors: Milne Tim , Bull C. Michael , Hutchinson Mark N.
Published: December 2003

The pygmy blue-tongue lizard, Tiliqua adelaidensis, had been considered extinct until its recent rediscovery near Burra in the mid-north of South Australia. The lizards apparently rely on spider burrows with a single entrance as refuge sites. In this paper we describe observations from all-day video recordings of the entrances of burrows occupied by lizards on 31 days across the spring and early summer of 1996. The lizards spent most of each day either retreated down the burrow or basking at the burrow entrance. Early in the season, when temperatures were cooler, lizards spent more of each day basking, and more of their basking time fully emerged from the burrow, than later in the season. Results are consistent with the hypothesis that the lizards thermoregulate by moving in and out of the burrow. Lizards also fed by making short excursions from the burrow, often to catch passing invertebrate prey, although they also fed on flowers early in spring. Later in the season lizards were more likely to vacate their burrows for longer times, or to move away from their burrows, and mating activity was observed when males approached burrows occupied by females. The observations suggest that pygmy blue-tongue lizards rely heavily on burrows for many activities, and that any conservation management scheme for this endangered species will rely on maintaining an adequate supply of burrows.
Habitat models for the four-fingered skink (Carlia tetradactyla) at the microhabitat and landscape scale
Authors: Fischer Joern , Lindenmayer David , Cowling Ann
Published: December 2003

A spatially nested experimental design was used to survey reptiles in a sheep- and cattle-grazing landscape in southern New South Wales, Australia. Sixteen landscape units were chosen on the basis of their aspect, topography and amount of tree cover. Across these landscape units, 288 pitfall traps were established at 144 plots arranged in 48 sites. Each plot was searched for reptiles and pitfall-trapped in two separate survey periods. The four-fingered skink (Carlia tetradactyla) was the most commonly encountered reptile species, and detailed statistical habitat models were constructed for this species. The four-fingered skink responded to both landscape scale and microhabitat variables. The species was more likely to be detected in landscape units characterised by a high amount of tree cover. Adults were most likely to inhabit microhabitats dominated by box- or gum-type eucalypts, with a moderate amount of canopy cover and with a large number of spiders. Juveniles were most likely to inhabit microhabitats with a moderate amount of weed invasion where shrubs were present. Finally, the four-fingered skink was more likely to be found at sites with at least two other co-occurring small reptile species. Body condition and tail loss of adult skinks were not related to the habitat or microhabitat where a given individual was found. The results are discussed in relation to current herpetological research, and some long-term conservation implications are highlighted.
Feral goat control in Egmont National Park, New Zealand, and the implications for eradication
Authors: Forsyth David M. , Hone Jim , Parkes John P. , Reid Gary H. , Stronge Dean
Published: December 2003

Feral goats in the 34 169 ha Egmont National Park (North Island, New Zealand) have been subject to sustained ground-based hunting with dogs since 1925. We analysed trends in hunting success from 1961 to 1999. During 1961–86 the catch per unit effort (CPUE) declined from 7 kills hunter–1 day–1 to <1 kill hunter–1 day–1. Since 1987 the CPUE has been maintained at low levels. The key impediment to switching from a strategy of sustained control to eradication is whether or not all goats can be put at risk. We suggest that managers test this experimentally in part of the park before embarking on an eradication programme. On the basis of an empirical estimate of rm and an assumption of logistic growth, we estimated the current population to be ~1047 animals. Removing 50% or 90% of the population annually would eradicate the population in >50 years or 12 years, respectively. Annual immigration of goats would prevent eradication under all scenarios.
On Machiavellian management
Authors: Buttery Ernest Alan , Richter Ewa Maria
Published: December 2003

Machiavellian principles are deemed to be applicable to our modern enterprises and have been said to offer critical advice to, and decisive discourse on, management thought and education. The paper revisits Machiavelli’s original arguments and examines these in the light of modern management theory. In particular, the paper scrutinizes the theory for relevance to today’s enterprise given that it was conceived in an era of competitive fragmentation of the Renaissance. The authors comment on a number of topics on which Machiavelli has offered advice, including takeovers of principalities, change, alliances, governance, and leadership principles for applicability to business. The paper concludes that the best way to manage complex business organizations is not through corrupting best management practice with the ideology of Machiavelli but to foster visionary well communicated business principles and practices.
The effective management of mergers
Authors: Nguyen Han , Kleiner Brian H.
Published: December 2003

There is a high failure rate of mergers and acquisitions. Most of them fail during the integration process. This article examines the organizational factors that negatively impact the integration process and suggests eight principles to make the integration more effective and successful. The factors discussed are based on empirical findings, literatures, and case studies. The major causes include improper managing and strategy, culture differences, delays in communication, and lack of clear vision. Therefore, the keys to successful integration process are a hands‐on leadership styles, a bias for action, involvement of the entire staff, continuous focus on customers, and most of all, open and honest communication with employees.
Traditional values for applying abilities and leader effectiveness in China
Authors: Tjosvold Dean , Yu Zi‐you , Liu Helen
Published: December 2003

Proposes that traditional Chinese values of leader as head can be useful in that they can promote applying abilities for mutual benefit for leadership and employees. A total of 200 managers working in organizations in Shanghai, China, indicated their traditional leadership values and level of applying abilities for mutual benefit with employees. A total of 200 employees working for these managers indicated their applying abilities with their manager and their manager’s leader effectiveness and their own job commitment. Applying abilities mediates between leader as head and leader effectiveness. Findings help to clarify that traditional Chinese leadership values involve support and relationship building, not necessarily domination and suppression. These results were interpreted as suggesting that Chinese managers and employees could develop effective leader relationships by strengthening their traditional values and orienting them to promoting applying abilities for mutual benefit.
Bayesian Estimation of Regional Production for CGE Modeling
Authors: Adkins Lee C. , Rickman Dan S. , Hameed Abid
Published: December 2003

Abstract Computable general equilibrium (CGE) models are often criticized for using restrictive functional forms and relying on external sources for parameter values in their calibration. CGE modelers argue that in many instances reliable econometric estimates of important model parameters are unavailable because they must be estimated using small numbers of time‐series observations. To address these criticisms, this paper uses a Bayesian approach to estimate the parameters of a translog production function in a regional computable general equilibrium model. Using priors from more reliable national estimates, and parameter restrictions required by neoclassical production theory, estimation is done by Markov chain Monte Carlo simulation. A stylized regional CGE model is then used to contrast policy responses of a Cobb‐Douglas specification with those from the estimated translog equation.
Location and Growth in the Brazilian Northeast
Authors: Lall Somik V. , Shalizi Zmarak
Published: December 2003

Abstract Clustering of economic performance across jurisdictions has generated considerable research on the spillovers and linkages among geographical neighbors. Much of this work, however, has been aspatial, implying that the influence of location attributes on growth has been largely ignored. In this paper, we examine the contribution of location to regional economic growth using municipio‐level data for the Brazilian Northeast—a historically lagging region of the country. We test if productivity among northeastern municipios is converging to a steady state and whether spatial externalities are linked to productivity growth in individual municipios. We find that, conditional on structural characteristics, productivity among municipios is converging at about 3 percent per year. Further, productivity in individual municipios is positively associated with own‐structural characteristics but negatively associated with productivity growth in neighboring municipios. This means that there are negative spatial externalities coming from productivity improvements in neighboring regions.
Exploring Relationships Between the Global and Regional Measures of Spatial Autocorrelation
Authors: Griffith Daniel A. , Wong David W. S. , Whitfield Thomas
Published: December 2003

AbstractThe objective of this research is to investigate dimensions of geographic variation in spatial dependency contained within large multilevel data sets. We calculate 1990 population density by census block group, county, and state for the 48 coterminous states and the District of Columbia of the United States, calculations of interest to a wide variety of spatial scientists. We explore relations between these levels and their variation across the nation. The empirical findings generated by this work furnish implications concerning the Modifiable Areal Unit Problem (MAUP), spatial autocorrelation statistics, scale effects, and resolution.
The Expected Maximum Distance Objective in Facility Location
Authors: Berman Oded , Drezner Zvi , Wesolowsky George O.
Published: December 2003

Abstract In this paper we introduce a new objective function for the minimax location problem. Every demand point generates demand for service with a given probability (during a given period of time) and the objective is to minimize the expected maximum distance. The planar problem is proven to be convex and thus standard solution techniques such as using the Solver in Excel can be applied for its solution. Properties for the problem on the network are proven and an efficient algorithm proposed for its solution.
Microeconomic Formulation and Estimation of a Residential Location Choice Model: Implications for the Value of Time
Authors: Pérez Patricio E. , Martínez Francisco J. , Ortúzar Juan de Dios
Published: December 2003

Abstract We formulate a microeconomic model of residential location choice behavior as an aggregate of the individual behaviors of household members, subject to individual time constraints and a common income budget. A simplified version of the model is estimated from stated preference rank‐order data, yielding a function that may be interpretated as a conditional indirect utility function. We consider Box‐Tukey transformations, segmentation by income class, and a consistent treatment of data at different rank depths using the simultaneous mixed‐estimation method. Measures of the household's willingness‐to‐pay (through rents) for reducing travel times to work and study in the short run, are interpreted as subjective values of time and compared with such values derived from mode choice models. Our results are plausible, and consistent with recent findings showing that the short‐run benefits of transport projects derived by transport models are larger than benefits measured at the land use system.
Purchasing Power Parities for Industry Comparisons Using Weighted Elteto–Koves–Szulc (EKS) Methods
Authors: Rao D. S. Prasada , Timmer Marcel P.
Published: December 2003

This study has three main objectives. First, it develops a generalization of the commonly used EKS method to multilateral price comparisons. It is shown that the EKS system can be generalized so that weights can be attached to each of the link comparisons used in the EKS computations. These weights can account for differing levels of reliability of the underlying binary comparisons. Second, various reliability measures and corresponding weighting schemes are presented and their merits discussed. Finally, these new methods are applied to an international data set of manufacturing prices from the ICOP project. Although theoretically superior, it appears that the empirical impact of the weighted EKS method is generally small compared to the unweighted EKS. It is also found that this impact is larger when it is applied at lower levels of aggregation. Finally, the importance of using sector specific PPPs in assessing relative levels of manufacturing productivity is indicated.
Imputed Rent and Income Inequality: A Decomposition Analysis for Great Britain, West Germany and the U.S.
Authors: Frick Joachim R. , Grabka Markus M.
Published: December 2003

This article deals with income advantages derived from owner‐occupied housing and their impact on the personal income distribution. Using micro‐data from the British Household Panel Study (BHPS), the German Socio‐Economic Panel (SOEP), and the U.S. Panel Study of Income Dynamics (PSID) we find distinct cross‐national differences in terms of the prevalence and extent of imputed rent. Results from inequality decomposition analyses show this overall impact to be the net effect of two conflicting changes: On the one hand there is increasing income inequality between the groups of owneroccupiers and renters, respectively, and, on the other hand, we find inequality to be decreasing within the group of those owner‐occupiers who own outright. When focussing on imputed rent as a means of old‐age provision, our results for all three countries show an income advantage for, as well as a poverty reducing effect among the elderly. The empirical findings support the claim for the need of an improved harmonization of this non‐cash income component especially for the purpose of cross‐national comparative research.
Finding out the Routes to Escape Poverty: The Relevance of Demographic vs. Labor Market Events in Spain
Authors: Cantó Olga
Published: December 2003

The knowledge of which events are most effective in pushing households out of deprivation should help in designing poverty‐alleviating social policy. Using longitudinal data for Spain, we analyze the nature of events pushing poor households out of poverty, adding an interesting decomposition of transitions: the occurrence of an event and the income change implied by it. We find that, similarly to other developed countries, the events that most help Spanish households in leaving poverty are related to changes in labor status of household members. However, non‐labor income changes are significantly more important in Spain than elsewhere.
New Labour and Higher Education: Dilemmas and Paradoxes
Authors: Brown Roger
Published: December 2003

David Blunkett's Greenwich speech (2000) set out what have become the main themes of New Labour's engagement with higher education, themes which were elaborated in the recent White Paper (DfES, 2003a). This paper draws attention to the dilemmas and paradoxes which arise from the difficulties of simultaneously satisfying the objectives which were set out in the aftermath of the 2001 general election, and from the trade off solutions and policies actually identified. The most fundamental conflict is between the desire to expand the system and the costs of that expansion. The author also identifies a conflict between institutional diversity and hierarchy and between exclusionism and accessibility. The paper concludes by suggesting that exclusionism is still alive and well under the government of a party that still has ‘Labour’ in its title.
The Labour Party and Higher Education: 1945–51
Authors: Bocock Jean , Taylor Richard
Published: December 2003

Assessments of Labour's achievements in education in the immediate post‐war period have been largely critical, but almost exclusively focused on schools’ reform. This article in contrast considers Labour's policies for higher education, particularly universities. Three themes dominated the post‐war agenda: science and technology, expansion (and access), and appropriate models of higher education. The demands of science and technology and the conse‐quent need for expansion were the main drivers in Labour's programme. But the failure to offer a clear view of post‐war development in higher education, together with a deep‐seated ambivalence as to the role of technology and vocational education in universities, meant that plans for science, technology and expansion were only partially realised. The issue of appropriate models of higher education has bedevilled subsequent Labour governments, including the present administration, in their search for a policy for higher education.
Institutional Diversity in UK Higher Education: Policy and Outcomes Since the End of the Binary Divide
Authors: Taylor John
Published: December 2003

Following the end of the binary system in 1992, UK higher education has witnessed a new approach to diversity based on institutional self‐determination within a common overall framework. Using analysis of statistical performance indicators, this paper shows that institutions have become more diverse, especially in terms of research activity. However, such diversity is unplanned and unco‐ordinated. Moreover, compared with some other countries, there is relatively little diversity in UK higher education. Further diversity will require radical changes within the university system, either by the operation of unfettered market forces or by increased intervention by Government or funding councils.
Higher Education in Further Education: Northern Ireland
Authors: Osborne R. D.
Published: December 2003

This paper reviews the provision of higher education courses in the further education sector in Northern Ireland. It charts the evolution of policy through the 1990s by examining major policy documents. It notes the chronic absence of reliable statistical and research evidence during this period. The available statistical evidence is reviewed. Key themes are identified including: localism, ‘non‐evidence based policy making’, higher education versus the demand for skills and community relations and equality. The innovative concept, now it would appear doomed, of the Springvale campus for west Belfast is examined. Finally, the paper notes that there is an urgent need to provide strategic direction to the further education sector as a whole.
Warning Against Faking on a Personality Test: Effects on Applicant Reactions and Personality Test Scores
Authors: Mcfarland Lynn A.
Published: December 2003

To reduce faking on personality tests, applicants may be warned that a social desirability scale is embedded in the test. Although this procedure has been shown to substantially reduce faking, there is no data that addresses how such a warning may influence applicant reactions toward the selection procedure or the relationships among personality constructs. Using an organizational justice framework, this study examines the effect of warning on procedural justice perceptions. Additionally, the extent to which warning changes the relationships among personality variables, socially desirable responding, and organizational justice variables, was explored. The results suggest that warning did not negatively affect test‐taker reactions. However, the relationships among the justice measures and the personality variables and socially desirable responding differed across the warned and unwarned groups. The organizational justice model fit best and there was less multicollinearity among the personality variables in the warned condition, compared to the unwarned condition. Thus, providing a warning appears to have positive consequences when using personality measures.
Expatriate Social Ties: Personality Antecedents and Consequences for Adjustment
Authors: Johnson Erin C. , Kristof‐brown Amy L. , Van vianen Annelies E.M. , De pater Irene E. , Klein Megan R.
Published: December 2003

This expaloratory study examines the relationship between personality characteristics (extraversion, core self evaluations), social tie characteristics (number, breadth, depth), and three types of expatriate adjustment (general, interaction, and work). Data was collected at two points in time from 75 expatriate employees from one organization on international assignments around the world. Results indicate that core self‐evaluations, but not extraversion, are positively related to the number of ties formed with other expatriates and host country nationals. Social ties with other expatriates were found to provide greater social support, but similar access to information, than those with host country nationals (HCNs). In general, depth and breadth of relationships with other expatriates predicted general and work adjustment; whereas, breadth and total number of relationships with HCNs predicted all three types of adjustment. Overall, these results provide initial support for the importance of social ties in facilitating expatriate adjustment.