bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk and Resilience: Inter‐organizational Learning Following the Northridge Earthquake of 17 January 1994
Authors: Comfort Louise K.
Published: October 2006

This article examines the tension between anticipation and resilience as a means to reduce risk. I argue that information drives the processes of order and entropy within a complex, adaptive system, altering both the internal relationships between the parts and the whole and the external relationships between the system and its environment. I examine a set of four theoretical measures of complex, adaptive systems in a case study of the inter‐organizational disaster response system that evolved following the Northridge, California Earthquake of 17 January 1994, and assess the extent to which these measures explain the dynamics of the ensuing disaster response system. Striking the balance between anticipation and resilience, order and chaos, requires a process of continual learning. If the ‘secret of safety lies in danger,’ structuring a process for continuous learning is a primary requirement for maintaining creativity and adaptation in practice.
The Kidnapping Crisis in the Philippines 1991–1993: Context and Management
Authors: Turner Mark
Published: October 2006

This article examines the increasing incidence of kidnapping in the Philippines between 1991 to 1993. The context of the kidnappings is analysed to demonstrate why they constituted a crisis. The incidence of the crime is investigated with particular reference to who was being kidnapped and to regional variations, theories and facts about the alleged perpetrators being delineated before outlining the various ways in which official agencies, non‐governmental organizations and individuals have responded to the crisis. The article concludes with some observations on the possibilities and problems of managing successful responses to such crises.
Disaster Beliefs and Ideological Orientation
Authors: Nilson Douglas
Published: October 2006

Disaster researchers contrast ‘social control’ and ‘social mobilization’ models of disaster response. Their perspectives suggest that the social mobilization model yields more rational resource allocation implications than the former model. Nevertheless, scholars and professionals have experienced only partial success worldwide in changing actual emergency management organizational approaches. An explanation may reside in the similarity of these models with a pair of deeply seated ideological viewpoints. ‘Left’ and ‘right’ belief systems are elaborated here, compared with the two disaster response models, and found to be consonant with those models in the direction expected.
Uncertainty in Environmental Emergencies: A Diagnostic Tool
Authors: De Marchi Bruna
Published: October 2006

The paper aims at stimulating reflection and debate on the issue of uncertainty as a key component of contingency planning and crisis management in environmental matters. It identifies and discusses different types of uncertainty, besides the scientific one which is already widely appreciated. A diagnostic tool is presented in the form of a checklist, designed for detecting and ranking the different types of uncertainty and for assessing levels of severity in a given contingency or crisis. The checklist is subsequently applied to the analysis of a classical disaster (the Seveso accident) to evaluate its usefulness and effectiveness. The author calls for further testing of the checklist by researchers, planners, regulators and practitioners and welcomes advice for its refinement.
Corporate Social Responsibility and Crisis Management: the democratic organisation and crisis prevention
Authors: Tombs Steve , Smith Denis
Published: October 2006

This paper explores the concept and nature of corporate social responsibility and relates this to the process of crisis management. The paper begins by outlining a typology of corporate social responsibility which uses categories drawn from political and social theory to organize the vast literature on this topic. In setting out this typology, the paper notes some of the weaknesses and contradictions within these types of corporate social responsibility. On the basis of such indications, it is argued that a ‘democratic’type is the most adequate form of corporate social responsibility. The paper then shifts to note some recent arguments concerning the various phases of crises and the nature and significance of crisis management as a process of crisis avoidance. These considerations lead to a consideration of the various interrelationships that exist between the two phenomenon. It is argued that there is a close affinity between crisis avoidance and democratic forms of corporate social responsibility. The paper concludes by highlighting the provisional nature of the points raised and sets out elements of a potentially fruitful research agenda around the relationships between crisis management and corporate social responsibility.
Organization and the Management of Risk in the Chemical Process Industry
Authors: Bax Erik H.
Published: October 2006

This article attempts to explain differences in the occurrence of incidents between two plants both belonging to the same parent company. A negative relationship was found between leadership stability and the occurrence of incidents, where the degree of leadership stability was defined as the degree to which management positions are submitted to changes of management personnel over time. In the second part of the article, a cross sectional analysis of the two plants is reported on the basis of which it is concluded that geographical dispersion of the technical installations; the degree of normative dependence of the parent company; the degree of centralization of authority relations; the organizational culture; the emphasis on training and the degree of informal social control are interdependent factors that can be related to plant safety.
Command and Control in Policing: A Systems Assessment of the Gold, Silver and Bronze Structure
Authors: Pearce Trevor , Fortune Joyce
Published: October 2006

A police force exhibits characteristics that are typical of those that can be found in many large, formal, bureaucratic organisations. It has a profound sense of hierarchy and shows a strong awareness of the power of procedure and the benefits to be gained from being systematic. It can be argued that such values and beliefs are entirely appropriate. Rules of evidence, for example, require a very strong discipline and offer very little opportunity for individual interpretation.

In the context of such an orderly, systematic approach, the application of systems thinking, with its emphasis on Weltanschauung, viewpoint and perspective, may at first appear inappropriate to police activity. However, this paper argues that this is not the case. It uses systems thinking to examine one important aspect of policing where method and procedure are very important ‐the command and control of major incidents/operations ‐ and shows that its application enables important lessons to be drawn about the strengths and weaknesses of the mechanisms in place.
High Reliability Organizations: Unlikely, Demanding and At Risk
Authors: La Porte Todd R.
Published: October 2006

The HRO project is cast within a broader socio‐political context, by first, reviewing its practical origins, its conceptual/logical framework, and a summary of the project's provisional findings, including a brief observation about the importance of a ‘culture of reliability.’Then some socio/political implications for HROs are explored as they assume the status of large technical systems (LTSs) and become quasi‐public institutions. This paper ends with a reflection on the challenges of institutional trustworthiness that confront HRO operators, managers, and overseers.
Heroes, Organizations and High Reliability
Authors: Schulman Paul R.
Published: October 2006

Organizational research has shown many cases where organizational ‘heroes’are honoured, and heroic tales are used not only in the process of building organizational reliability and performance, but for clarifying organizational values and culture and transmitting them from one generation to the next. Some high‐reliability organizations studied also display these properties; yet, there are some that are actively ‘anti‐heroic,’disparaging individual exploits. An inquiry into the role of heroes and heroics in organizations leads to a typology by which hero‐avoiding and hero‐seeking organizations can be characterized and shows that both types are adaptations to their particular technical and functional environments. A great deal more remains to be learned about the dynamics of organizations seeking and maintaining reliability in very demanding circumstances before we can fully understand how the balance between holistic control and heroics might be chosen.
The Integrity of the Managerial State
Authors: Bovens Mark
Published: October 2006

Corruption is back on the public agenda in many European countries. After years of neglect and diffidence, politicians, administrators and scholars have voiced serious concern about the moral integrity of the public sector. However, there is something peculiar about these debates in The Netherlands. As yet, there is no empirical data available that confirms this generally accepted picture of a public service tainted by corruption. This paper tries to explain this huge discrepancy between public concern and empirical data. The public concern, it is argued, is not just a matter of symbolics or bureau‐politics, it is also a case of institutional insecurity, caused by the transformation that the public sector is going through. Never before has government in The Netherlands, as in many other Western countries, engaged in commercial or market‐oriented activities as it has in the last decade. Step by step, the managerial state is replacing the administrative state. The present public debate about integrity in government is at least partially a reflection of the struggle in the public sector to cope with the issues that are raised by the managerial shift in Western governments. Some of the issues are probably transitional in character; they can be designed away. Some important parts of the managerial shift might cause permanent perplexities. The reason for this could be the institutional instability, both normatively and practically, of mixed arrangements.
A Bureau‐Political Model of Local Networks and Public/Private Partnerships: Responses to Crisis and Change
Authors: Jacobs Brian D.
Published: October 2006

The aim in this paper is to describe the bureau‐political model and suggest where it might be applied in further research. The focus is upon the diverse and often seemingly chaotic public organizational and policy responses to urban crises and policy change. The research covers the factors that shape local level organizational structures and policy especially in public/private sector partnerships (PPPs). The bureau‐political model presented here derives from research originally published in this journal (Jacobs, 1993). The 1993 paper dealt with policy responses to urban riots in the United Kingdom (UK) and the United States (US). Cases presented elsewhere (Jacobs, 1986; 1988; 1989; 1992) also inform the present research.
Beyond the Crisis Window for Reform: Some Ramifications for Implementation
Authors: Boin R. Arjen , Otten Marc H.P.
Published: October 2006

In the policy literature, crises are often presented as opportunities for reform initiation. Little is known, however, about the effects that crises may have on the implementation of such reform initiatives. This article explores how a crisis may affect the administrative relations between central authorities and field administrations. The crisis impact on central‐field relations appears to be twofold. First, a crisis may facilitate, if not induce, the centralization of decision‐making processes. Secondly, a crisis may affect the degree of consensus between central authorities and field administrations with regard to problem definitions and preferred solutions.

This paper uses a case study of the Dutch prison system to explore the crisis impact on these two dimensions of central‐field relations. In this particular case, crisis circumstances did not facilitate a successful implementation of a major policy overhaul. We suggest that crises may offer opportunities for reform implementation, but only under highly restricted conditions. When these conditions are not met, crises may have perverse effects on central‐field relations which limit the prospects for the effective implementation of reform.
Peoples' Perception and Response to Floodings: The Bangladesh Experience
Authors: Rahman Atiur
Published: October 2006

Bangladesh, a test case of disaster management, has been continuously internalizing lessons learned by the people, the bureaucracy and non‐governmental organizations (NGOs), after successfully responding to major natural disasters, particularly floods. The unprecedented flood of 1988 was a great educator to almost all stakeholders in Bangladesh. Since then, it has improved its capacity to cope with disasters despite some failures in its management of the macro‐economy and governance. Credit goes mostly to the ordinary people whose resilience and creativity during and after disasters have been quite heroic. This paper makes an attempt at documenting peoples’perception and response to major floods at different stages of the crisis. An illustrative plan for coping with flood disasters encompassing these stages has also been designed and outlined in this paper.
Midkine, a heparin‐binding growth factor, is expressed in neural precursor cells and promotes their growth
Authors: Zou Peng , Muramatsu Hisako , Miyata Takaki , Muramatsu Takashi
Published: October 2006

Midkine, a heparin‐binding growth factor, was found to be expressed in neural precursor cells, which consist of neural stem cells and the progenitor cells. When embryonic brain cells were allowed to form neurospheres enriched in neural precursor cells, numbers were significantly smaller from the midkine‐deficient brain than from the wild‐type brain. Dissociated neurosphere cells yielded nestin‐positive neural precursor cells and differentiated neuronal cells upon culture on a substratum. Neural precursor cells from the midkine‐deficient brain spread poorly and grew less effectively on a substratum coated with poly‐l‐lysine than the cells on midkine‐coated substratum. Neural precursor cells from the wild‐type brain spread and grew well on both the substrata. Differentiation to neurons and glia cells was not affected by the absence of midkine. Heparitinase digestion of dissociated neurosphere cells resulted in poor growth of neural precursor cells, while chondroitinase digestion had no effect. These results indicate that midkine is involved in the growth of neural precursor cells and suggest that the interaction with heparan sulfate proteoglycans is important in midkine action to these cells.
Potential implications of endogenous aldehydes in β‐amyloid misfolding, oligomerization and fibrillogenesis
Authors: Chen Kun , Maley Jason , Yu Peter H.
Published: October 2006

Aldehydes are capable of inducing protein cross‐linkage. An increase in aldehydes has been found in Alzheimer's disease. Formaldehyde and methylglyoxal are produced via deamination of, respectively, methylamine and aminoacetone catalyzed by semicarbazide‐sensitive amine oxidase (SSAO, EC 1.4.3.6. The enzyme is located on the outer surface of the vasculature, where amyloidosis is often initiated. A high SSAO level has been identified as a risk factor for vascular disorders. Serum SSAO activity has been found to be increased in Alzheimer's patients. Malondialdehyde and 4‐hydroxynonenal are derived from lipid peroxidation under oxidative stress, which is also associated with Alzheimer's disease. Aldehydes may potentially play roles in β‐amyloid aggregation related to the pathology of Alzheimer's disease. In the present study, thioflavin‐T fluorometry, dynamic light scattering, circular dichroism spectroscopy and atomic force microscopy were employed to reveal the effect of endogenous aldehydes on β‐amyloid at different stages, i.e. β‐sheet formation, oligomerization and fibrillogenesis. Formaldehyde, methylglyoxal and malondialdehyde and, to a lesser extent, 4‐hydroxynonenal are not only capable of enhancing the rate of formation of β‐amyloid β‐sheets, oligomers and protofibrils but also of increasing the size of the aggregates. The possible relevance to Alzheimer's disease of the effects of these aldehydes on β‐amyloid deposition is discussed.
15‐deoxy‐Δ12,14‐prostaglandin J2 (15d‐PGJ2) and ciglitazone modulate Staphylococcus aureus‐dependent astrocyte activation primarily through a PPAR‐γ‐independent pathway
Authors: Phulwani Nirmal K. , Feinstein Douglas L. , Gavrilyuk Vitaliy , Akar Candan , Kielian Tammy
Published: October 2006

Brain abscesses arise from a focal parenchymal infection by various pathogens, particularly Staphylococcus aureus. We have shown that astrocytes are activated upon exposure to S. aureus and may contribute to the excessive tissue damage characteristic of brain abscess. Therefore, modulating astrocyte activation may facilitate a reduction in brain abscess severity. Peroxisome proliferator activated receptor‐γ (PPAR‐γ) agonists are potent inhibitors of microglial activation; however, the effects of these compounds on S. aureus‐dependent astrocyte activation have not yet been examined. Here, we demonstrate that two chemically distinct PPAR‐γ agonists, 15‐deoxy‐Δ12,14‐prostaglandin J2 (15d‐PGJ2) and ciglitazone, suppress the production of several pro‐inflammatory molecules in S. aureus‐stimulated astrocytes including interleukin‐1β and nitric oxide (NO). Interestingly, 15d‐PGJ2 attenuated Toll‐like receptor 2 (TLR2) and inducible nitric oxide synthase expression, but failed to modulate macrophage inflammatory protein‐2 (MIP‐2/CXCL2) production, suggesting that 15d‐PGJ2 is not a global inhibitor of astrocyte activation. Another novel finding of this study was the fact that both 15d‐PGJ2 and ciglitazone were capable of attenuating pre‐existing astrocyte activation, indicating their potential benefit in a therapeutic setting. Importantly, 15d‐PGJ2 and ciglitazone were still capable of inhibiting S. aureus‐induced pro‐inflammatory mediator release in PPAR‐γ‐deficient astrocytes, supporting PPAR‐γ‐independent effects of these compounds. Collectively, these results suggest that 15d‐PGJ2 and ciglitazone exert their anti‐inflammatory actions on astrocytes primarily independent of the PPAR‐γ pathway.
Ethanol inhibits cold‐menthol receptor TRPM8 by modulating its interaction with membrane phosphatidylinositol 4,5‐bisphosphate
Authors: Benedikt Jan , Teisinger Jan , Vyklicky Ladislav , Vlachova Viktorie
Published: October 2006

Ethanol has opposite effects on two members of the transient receptor potential (TRP) family of ion channels: it inhibits the cold‐menthol receptor TRPM8, whereas it potentiates the activity of the heat‐ and capsaicin‐gated vanilloid receptor TRPV1. Both thermosensitive cation channels are critically regulated by the membrane lipid, phosphatidylinositol 4,5‐bisphosphate (PIP2). The effects of this phospholipid on TRPM8 and TRPV1 are also functionally opposite: PIP2 is necessary for the activation of TRPM8 but it constitutively inhibits TRPV1. This parallel led us to investigate the possible role of PIP2 in the ethanol‐induced modulation of rat TRPM8, heterologously expressed in HEK293T cells. In this study, we characterize the effects of ethanol (0.1–10%) on whole‐cell currents produced by menthol and by low temperature (< 17°C). We show that the inclusion of PIP2 in the intracellular solution results in a strong reduction in the ethanol‐induced inhibition of menthol‐evoked responses. Conversely, intracellular dialysis with anti‐PIP2 antibody or with the PIP2 scavenger, poly l‐lysine, enhanced the ethanol‐induced inhibition of TRPM8. A 20 min pre‐incubation with wortmannin caused a modest decrease in inhibition produced by 1% ethanol, indicating that the ethanol‐induced inhibition is not mediated by lipid kinases. These findings suggest that ethanol inhibits TRPM8 by weakening the PIP2–TRPM8 channel interaction; a similar mechanism may contribute to the ethanol‐mediated modulation of some other PIP2‐sensitive TRP channels.
Impaired long‐term depression in P2X3 deficient mice is not associated with a spatial learning deficit
Authors: Wang Yue , Mackes Jennifer , Chan Stephen , Haughey Norman J. , Guo Zhihong , Ouyang Xin , Furukawa Katsutoshi , Ingram Donald K. , Mattson Mark P.
Published: October 2006

The hippocampus is a brain region critical for learning and memory processes believed to result from long‐lasting changes in the function and structure of synapses. Recent findings suggest that ATP functions as a neurotransmitter or neuromodulator in the mammalian brain, where it activates several different types of ionotropic and G protein‐coupled ATP receptors that transduce calcium signals. However, the roles of specific ATP receptors in synaptic plasticity have not been established. Here we show that mice lacking the P2X3 ATP receptor (P2X3KO mice) exhibit abnormalities in hippocampal synaptic plasticity that can be restored by pharmacological modification of calcium‐sensitive kinase and phosphatase activities. Calcium imaging studies revealed an attenuated calcium response to ATP in hippocampal neurons from P2X3KO mice. Basal synaptic transmission, paired‐pulse facilitation and long‐term potentiation are normal at synapses in hippocampal slices from P2X3KO. However, long‐term depression is severely impaired at CA1, CA3 and dentate gyrus synapses. Long‐term depression can be partially rescued in slices treated with a protein phosphatase 1–2 A activator or by postsynaptic inhibition of calcium/calmodulin‐dependent protein kinase II. Despite the deficit in hippocampal long‐term depression, P2X3KO mice performed normally in water maze tests of spatial learning, suggesting that long‐term depression is not critical for this type of hippocampus‐dependent learning and memory.
Evidence that quinolinic acid severely impairs energy metabolism through activation of NMDA receptors in striatum from developing rats
Authors: Ribeiro César A. J. , Grando Vanessa , Dutra Filho Carlos S. , Wannmacher Clóvis M. D. , Wajner Moacir
Published: October 2006

In the present study we investigated the effect of intrastriatal administration of 150 nmol quinolinic acid to young rats on critical enzyme activities of energy production and transfer, as well as on 14CO2 production from [1–14C]acetate at distinct periods after quinolinic acid injection. We observed that quinolinic acid injection significantly inhibited complexes II (50%), III (46%) and II–III (35%), as well as creatine kinase (27%), but not the activities of complexes I and IV and citrate synthase in striatum prepared 12 h after treatment. In contrast, no alterations of these enzyme activities were observed 3 or 6 h after quinolinic acid administration. 14CO2 production from [1–14C]acetate was also significantly inhibited (27%) by quinolinic acid in rat striatum prepared 12 h after injection. However, no alterations of these activities were observed in striatum homogenates incubated in the presence of 100 μm quinolinic acid . Pretreatment with the NMDA receptor antagonist MK‐801 and with creatine totally prevented all inhibitory effects elicited by quinolinic acid administration. In addition, α‐tocopherol plus ascorbate and the nitric oxide synthase inhibitor l‐NAME completely abolished the inhibitions provoked by quinolinic acid on creatine kinase and complex III. Furthermore, pyruvate pretreatment totally blocked the inhibitory effects of quinolinic acid injection on complex II activity and partially prevented quinolinic acid‐induced creatine kinase inhibition. These observations strongly indicate that oxidative phosphorylation, the citric acid cycle and cellular energy transfer are compromised by high concentrations of quinolinic acid in the striatum of young rats and that these inhibitory effects were probably mediated by NMDA stimulation.
Compositional similarity and the distribution of geographical range size for assemblages of native and non‐native species in urban floras
Authors: La Sorte Frank A. , McKinney Michael L.
Published: October 2006

There is evidence that, within a region, non‐native species introduced from nearby sources (extralimital native) promote homogenization and non‐native species introduced from distant sources (exotic) promote differentiation of species composition. A possible explanation for these associations is that they are related to differences in the distribution of geographical range size. We test this by examining geographical ranges, delineated within a defined region, for assemblages of vascular plants in eight urban floras in the USA. Across floras, native species had the largest, least variable ranges and the greatest proportion of shared species. Exotic species had the most variable ranges with concentrations of species with small and large ranges and the lowest proportion of shared species. Extralimital natives had concentrations of species with intermediate‐sized ranges and intermediate proportions of shared species. These results suggest that patterns of compositional similarity were associated with the relative strength and equality of two opposing patterns within species range size distributions: species with small vs. large ranges. In general, concentrations of species with small ranges promoted low levels and concentrations of species with large ranges promoted high levels of compositional similarity. However, patterns documented for exotic species will likely continue to develop, possibly taking on new forms, depending on how geographical distributions and the rate of introductions of exotic species change over time. Our findings also suggest that processes underlying these patterns have operated at two spatiotemporal scales. The first scale reflects historical consequences of anthropogenic activities occurring within regional extents that have promoted the introduction of extralimital natives; the second scale reflects modern consequences of anthropogenic activities operating at an increasingly global extent that have promoted the introduction of exotic species.
Species richness correlations among primary producers in boreal forests
Authors: Dynesius Mats , Zinko Ursula
Published: October 2006

Close correlations in species numbers may make it possible to indirectly assess the species richness of difficult taxonomic groups by investigating indicator groups, for which data are more easily collected. We asked if species numbers correlate among the four dominating groups of primary producers in boreal forests (liverworts, macrolichens, mosses, and vascular plants) and if substrate affiliation of species (ground vs. other substrates), sample plot size (0.01–1000 m2), and stand age (young vs. old) influence correlation strength. We used three sets of study plots from northern Sweden each including wide ranges of species richness. Although there are large differences in the ecophysiology and substrate use of vascular plants and the two bryophyte groups (mosses and liverworts), we found strong positive correlations among them not previously reported from boreal forests. In contrast, no correlation in total species richness was found between macrolichens and the two bryophyte groups, despite large overlaps in their ecology. We suggest that the positive correlations among land plants (liverworts, mosses, and vascular plants) are linked to positive relationships between site moisture and species number for all three groups. In contrast, total species number of macrolichens has not been shown to be strongly associated with moisture. However, ground‐living lichens and mosses correlated negatively in old forests. This may relate to the inability of macrolichens to exploit shaded and wet old forest ground, a habitat that is used by many moss species. Furthermore, lichens and mosses of ‘other substrates’ correlated positively in old forests, probably because the amount of boulders was positively related to species richness in both groups. Generally, correlations became stronger with increasing plot size, whereas stand age had relatively little influence. We conclude that vascular plants could be used as an indicator group for species richness of mosses and liverworts in boreal landscapes.
Why are ferns regularly over‐represented on state and provincial rare plant lists?
Authors: Wild Matthew , Gagnon Daniel , Bouchard André
Published: October 2006

Several recent studies have suggested that rare species are not randomly distributed throughout plant taxa. This would appear to apply to North American ferns, which are frequently over‐represented on local lists of rare plant species. However, such lists often paint a skewed portrait of the true situation because of our tendency to recognize the rarity of well‐known and charismatic species while ignoring that of lesser‐known or less‐appreciated species. In order to verify if this over‐representation of ferns is a real and consistent trend throughout local floras in North America, we used data from what we consider to be the most complete and objective available database: NatureServe Explorer (http://www.natureserve.org/explorer/). We compiled data on total vascular plant species, total fern species, as well as rare vascular plant species and rare fern species for each North American subnational (Canadian province or US state) flora. Rare species were defined as those belonging to one of NatureServe's ‘at risk’ categories. The null hypothesis that the contribution of rare ferns to total rare species did not differ from their contribution to the total vascular flora was assessed using χ2. Out of 64 subnational floras, we obtained significantly higher values than expected in 28 cases, and significantly lower in only one case. Similar trends hold true for individual fern families. These tendencies could be related to several factors of anthropogenic, biological, climatological, evolutionary, and geographical origin. However, we believe that the main reason is related to scale, namely the geopolitical units at which rarity is often studied. Our results illustrate one of the problems of a parochial approach to conservation, where the perceived rarity of an entire taxon is exaggerated because of the scale at which rarity is addressed.
Comparing agglomerative clustering and three weed classification frameworks to assess the invasiveness of alien species across spatial scales
Authors: Lawes Roger A. , Murphy Helen T. , Grice Anthony C.
Published: October 2006

To prioritize weed management at the catchment scale, information is required on the species present, their relatively frequency, abundance, and likely spread and impact. The objective of this study was to classify the invasiveness of alien species that have invaded the Upper Burdekin Catchment in Queensland, Australia, at three spatial scales. A combination of three published weed classification frameworks and multivariate techniques were employed to classify species based on their frequency and cover at a range of spatial scales. We surveyed the Upper Burdekin Catchment for alien species, and for each species determined the following distribution indices — site frequency, total cover, transect frequency per site frequency and quadrat frequency per site frequency, cover per quadrat when present, cover per transect when present, and cover per site when present. These indices capture the effect of species abundance and frequency between sites (site frequency and total cover), within sites (transect frequency per site and cover per transect when present), and within transects (quadrat frequency per site frequency and cover per site). They were used to classify the species into seven groups using a hierarchical cluster analysis. The relationship between the indices was explored to determine how effective the small scale, site‐specific indices were at predicting the broader, landscape‐scale patterns. Strong correlations were observed between transect frequency per site and frequency (r2 = 0.89) and cover per transect when present and total cover (r2 = 0.62). This suggests that if a weed is abundant at the site level, it has the potential to occupy large areas of the catchment. The species groupings derived from the application of the three published weed classification frameworks were compared graphically to the groupings derived from the cluster analysis. One of the frameworks classified species into three groups. The other two frameworks classified species into four groups. There was a high degree of subjectivity in applying the frameworks to the survey data. Some of the data were of no relevance to the classification frameworks and were therefore ignored. We suggest that the weed classification frameworks should be used in conjunction with existing multivariate techniques to ensure that classifications capture important natural variations in observed data that may reflect invasion processes. The combined use of the frameworks and multivariate techniques enabled us to aggregate species into categories appropriate for management.
Prospects for population expansion of the exotic aoudad (Ammotragus lervia; Bovidae) in the Iberian Peninsula: clues from habitat suitability modelling
Authors: Cassinello Jorge , Acevedo Pelayo , Hortal Joaquín
Published: October 2006

We studied the geographical distribution and habitat suitability of an introduced ungulate, the aoudad (Ammotragus lervia), that is currently expanding its range in south‐eastern Iberian Peninsula. We assessed the niche of the species using Ecological Niche Factor Analysis (ENFA) on (1) environmental variables (climate and habitat type), and (2) potential aoudad landscape avoidance and human disturbance variables. We compared both niche descriptions to study the impact of human interference on niche selection of the species. ENFA models were calibrated using data on the population expanded from the original release location, in Sierra Espuña mountains, and validated using data from another free‐ranging population, originated independently in the Alicante province. The habitat suitability model for the purely environmental niche predicts a potential distribution along a SW–NE axis in the study area, following the Cordillera Sub‐Bética mountain range, being constrained by low winter precipitation, high altitude, high terrain slope, and the presence of forest. In addition to these ecological traits, roads and landscape use restricted the environmental range potentially available for the species. Since the aoudad is a potential competitor of native ungulates and a threat to endemic flora, prospects for its potential dispersion might be of great conservation value.
Biogeochemical modelling of the rise in atmospheric oxygen
Authors: CLAIRE M. W. , CATLING D. C. , ZAHNLE K. J.
Published: October 2006

Understanding the evolution of atmospheric molecular oxygen levels is a fundamental unsolved problem in Earth's history. We develop a quantitative biogeochemical model that simulates the Palaeoproterozoic transition of the Earth's atmosphere from a weakly reducing state to an O2‐rich state. The purpose is to gain an insight into factors that plausibly control the timing and rapidity of the oxic transition. The model uses a simplified atmospheric chemistry (parameterized from complex photochemical models) and evolving redox fluxes in the Earth system. We consider time‐dependent fluxes that include organic carbon burial and associated oxygen production, reducing gases from metamorphic and volcanic sources, oxidative weathering, and the escape of hydrogen to space. We find that the oxic transition occurs in a geologically short time when the O2‐consuming flux of reducing gases falls below the flux of organic carbon burial that produces O2. A short timescale for the oxic transition is enhanced by a positive feedback due to decreasing destruction of O2as stratospheric ozone forms, which is captured in our atmospheric chemistry parameterization. We show that one numerically self‐consistent solution for the rise of O2involves a decline in flux of reducing gases driven by irreversible secular oxidation of the crust caused by time‐integrated hydrogen escape to space in the preoxic atmosphere, and that this is compatible with constraints from the geological record. In this model, the timing of the oxic transition is strongly affected by buffers of reduced materials, particularly iron, in the continental crust. An alternative version of the model, where greater fluxes of reduced hydrothermal cations from the Archean seafloor consume O2, produces a similar history of O2and CH4. When climate and biosphere feedbacks are included in our model of the oxic transition, we find that multiple ‘Snowball Earth’ events are simulated under certain circumstances, as methane collapses and rises repeatedly before reaching a new steady‐state.
Mineral activity–composition relations and petrological calculations involving cation equipartition in multisite minerals: a logical inconsistency
Authors: HOLLAND T. J. B. , POWELL R.
Published: October 2006

Equipartition is an assumption that preserves the same relative fraction of the cations on each site, originally used just to distribute cations such as Fe and Mg over two or more sites during mineral recalculation. This approximation has been used in almost all thermometry and barometry applications in petrology involving pyroxene, amphibole, chlorite and biotite mica. It has also become the default approach used in deriving activity–composition relations in multisite minerals where details of element partitioning among the sites is unknown and therefore assumed to be random. It is shown that, where a third element, such as Al, resides on just one of the sites, equipartition introduces a serious logical and numerical inconsistency between the enthalpy and entropy of mixing. In particular, application of equipartition is demonstrated to be equivalent to treating the solution as one in which all cations reside on one type of site. For example, in the case of aluminous orthopyroxene the equipartition assumption implies that Fe, Mg and Al are distributed across two identical sites, and that end‐members such as Mg‐tschermak's pyroxene have enthalpies characterized by a totally disordered distribution of Mg and Al over the M2 and M1 sites. Clearly this is unsupportable, and solid solutions should be treated with appropriate thermodynamics for order–disorder. For phases where element partitioning data are unavailable, we offer a simple alternative strategy, using the ordering of Fe and Mg on M1 and M2 sites in biotite as an example.
Acute transfusion reactions in the pediatric intensive care unit
Authors: Gauvin France , Lacroix Jacques , Robillard Pierre , Lapointe Hélène , Hume Heather
Published: October 2006

BACKGROUND: Acute transfusion reactions (ATRs) are probably underdiagnosed in critically ill children because associated symptoms can frequently be attributed to the patient’s underlying disease. This study was undertaken to determine the incidence, type, imputability, and severity of ATRs observed in a tertiary care pediatric intensive care unit (PICU).

STUDY DESIGN AND METHODS: All transfusions of labile blood product administered to consecutive patients admitted to our PICU, between February 2002 and February 2004, were prospectively recorded. For each transfusion, the bedside nurse recorded the patient’s status before, during, and up to 4 hours after the transfusion, as well as the presence of any new sign or symptom suggesting an ATR. Three independent experts retrospectively reviewed all transfusion event reports and hospital charts. The presence, type, imputability, and severity of ATRs were adjudicated by consensus of two of three experts (Delphi method), with predefined criteria.

RESULTS: A total of 2509 transfusions were administered to 305 patients during the study. Forty transfusion events (1.6%) were confirmed to be ATRs by expert consensus: 24 febrile nonhemolytic, 6 minor allergic, 4 isolated hypotension, 3 bacterial contamination, 1 major allergic (anaphylactic shock), 1 TRALI, and 1 hemolytic reaction. Imputability of ATRs was probable or possible in 35 cases (88%). ATRs led to an immediate vital threat in 15 percent of cases.

CONCLUSION: Improved surveillance of transfusions given to PICU patients and better knowledge of these reactions by health care professionals should improve the safety of transfusions in the PICU.
A study of the agreement between patient self‐assessment and study personnel assessment of bleeding symptoms
Authors: Webert Kathryn E. , Cook Richard J. , Couban Stephen , Carruthers Julie , Heddle Nancy M.
Published: October 2006

BACKGROUND: Clinical trials investigating new platelet transfusion therapies frequently require the assessment of bleeding for the study outcome. These assessments are commonly performed by study personnel and can be time‐consuming. The purpose of this study was to assess whether patients were able to reliably assess their bleeding status on a daily basis.

STUDY DESIGN AND METHODS: Patients admitted to hospital to receive chemotherapy for acute leukemia or to undergo allogeneic peripheral blood progenitor cell transplant were included. Patients were given an introduction to a form for documenting the occurrence of 16 bleeding symptoms. Patients completed this form and were examined daily by a study assessor. A weekly health record review was also performed by a study assessor. The agreement between raters was determined by calculating the raw agreement, chance‐corrected agreement, and chance‐independent agreement.

RESULTS: Thirty‐five patients completed 458 assessment forms that were paired with 559 forms completed by a study assessor with 450 matched forms available for analysis (mean, 12.86 per patient). Agreement for most individual bleeding symptoms was high. Thirteen items had agreement greater than 90 percent and all items had agreement greater than 77 percent. The lowest agreement was seen for skin symptoms: petechiae (89.2%), purpura (80.9%), and ecchymosis (77.6%). The negative predictive value of patient self‐assessment was high (range, 71.1%‐100%) whereas the positive predictive value was lower (range, 0%‐86.5%).

CONCLUSION: The reliability was very good between patients and study assessors with the patients reporting excellent negative predictive value and variable positive predictive value.
Large‐scale expansion and transplantation of CD34+ hematopoietic cells: in vitro and in vivo confirmation of neutropenia abrogation related to the expansion process without impairment of the long‐term engraftment capacity
Authors: Boiron Jean‐Michel , Dazey Bernard , Cailliot Christian , Launay Béatrice , Attal Michel , Mazurier Frédéric , McNiece Ian K. , Ivanovic Zoran , Caraux Jean , Marit Gérald , Reiffers Josy
Published: October 2006

BACKGROUND: Herein are reported the results obtained in all multiple myeloma patients transplanted with peripheral blood hematopoietic progenitor cells submitted to ex vivo expansion.

STUDY DESIGN AND METHODS: Patients had blood progenitor cell mobilization with cyclophosphamide and filgrastim. CD34+ cells were expanded for 10 days in a medium containing granulocyte–colony‐stimulating factor (G‐CSF), stem cell factor, and megakaryocyte growth and development factor (MGDF). Twenty‐seven patients underwent transplantation with expanded and nonexpanded cells and 7 patients underwent transplantation with expanded cells only.

RESULTS: The median fold cell expansion was 29.1. The number of colony‐forming unit–granulocyte‐macrophage (CFU‐GM) and CD34+ cells, and the long‐term culture‐initiating cell (LTC‐IC) activity increased with median fold values of 14.7, 2.75, and 2.25, respectively. Postmyeloablative neutropenia was abrogated in 24 of 27 patients transplanted with expanded cells plus nonexpanded cells. The median duration of severe neutropenia was 0 days and correlated with the number of cells and CFU‐GM infused. Survival was similar to that of a historical control group. Our LTC‐IC and NOD‐SCID mice studies showed that the expanded cells are able of sustaining long‐term hematopoiesis. Seven other patients received transplantation with expanded cells alone. Absolute neutropenia was abrogated in 6 patients. The median duration of neutropenia was 0 days. Two patients who received the lower number of total cells or CFU‐GM had brief secondary neutropenia, which resolved after G‐CSF injections.

CONCLUSION: CD34+ cells expanded ex vivo can abrogate absolute and severe neutropenia after high‐dose therapy. The results of the amplification process are strongly related to the delay of hematopoietic recovery.
Spatial Interpolation and Disaggregation of Multipliers
Authors: Oosterhaven Jan
Published: October 2006

Most non‐survey methods of estimating single‐region multipliers have been shown to produce a systematic upward bias, unless a considerable amount of “superior” data is added. Here it is argued that this conclusion does not need to apply to the case of a non‐survey, spatial disaggregation of multipliers. The method proposed consists of four steps with two substantive formulas. The first secures the non‐survey interpolation of the lacking intra‐regional multipliers for the smaller regions by means of regression. The second secures the non‐survey spatial disaggregation of the inter‐regional spillovers by means of second‐order distance decays. The method is illustrated numerically by means of the interpolation and disaggregation of the 2 × 14 Type II biregional employment multipliers for aggregate Dutch regions into one 40 × 40 inter‐regional employment multiplier matrix for the Netherlands as a whole.
Unconditional Maximum Likelihood Estimation of Linear and Log‐Linear Dynamic Models for Spatial Panels
Authors: Elhorst J. Paul
Published: October 2006

This article hammers out the estimation of a fixed effects dynamic panel data model extended to include either spatial error autocorrelation or a spatially lagged dependent variable. To overcome the inconsistencies associated with the traditional least‐squares dummy estimator, the models are first‐differenced to eliminate the fixed effects and then the unconditional likelihood function is derived taking into account the density function of the first‐differenced observations on each spatial unit. When exogenous variables are omitted, the exact likelihood function is found to exist. When exogenous variables are included, the pre‐sample values of these variables and thus the likelihood function must be approximated. Two leading cases are considered: the Bhargava and Sargan approximation and the Nerlove and Balestra approximation. As an application, a dynamic demand model for cigarettes is estimated based on panel data from 46 U.S. states over the period from 1963 to 1992.
Modeling the Impact of Business‐to‐Business Electronic Commerce on the Organization of the Logistics Industry
Authors: Aoyama Yuko , Ratick Samuel J. , Schwarz Guido
Published: October 2006

In this article, we analyze patterns and recent trends of the logistics industry with specific emphasis on the impact of business‐to‐business (B‐to‐B) electronic commerce on its industrial organization. From this conceptualization, we develop an optimization‐based logistics model comprising two interlinked networks representing commodity flow and information flow, respectively. The model is operationalized using Monte Carlo simulation to highlight possible scenarios of logistics industry changes in response to the use of B‐to‐B e‐commerce. Through this endeavor, we examine how new technologies affect the cost of information and transportation transactions in the logistics industry.