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PubMed2004

Recent evolution of natural hazard management policy in France, the example of Serre-Chevalier (French Alps).

Since the 1960s, the development of the Serre-Chevalier winter and summer resort has led to a rapid extension of the urban fabric on the territory of the village of St-Chaffrey. On July 9, 1981, the new neighborhoods built on the alluvial fan of the Verdarel torrent were partly devastated by a channeled debris flow. This disaster prompted the civil authorities to set up an extensive fluvial regulation system, which rapidly contributed to recreating a climate of confidence and security favorable to continuing urban expansion. The combination of catastrophic floods in July 1995, and a new security-oriented national policy on natural hazards, nevertheless led to a return to precautionary measures. The St-Chaffrey town council has therefore been forced by the State to accept a building-free zone on the land-use plan. This measure is perceived as a real denial of the local efficacy of the flood and landslide risk management policy as carried out by the council of St-Chaffrey during the previous 20 years.

Conservation of Natural Resources↗

PubMed2004

Landscape character and fish assemblage structure and function in western Lake Superior streams: general relationships and identification of thresholds.

As part of a comparative watershed project investigating land-cover/land-use disturbance gradients for streams in the western Lake Superior Basin, we examined general relationships between landscape character and fish assemblage structure and function. We also examined the shape of those relationships to identify discontinuity thresholds where small changes in landscape character were associated with marked shifts in the fish assemblages. After completing a geographic analysis of second- and third-order watersheds in the western Lake Superior drainage, we randomly selected 48 streams along mature forest and watershed storage gradients in 2 hydrogeomorphic regions as our study sites. During the summers of 1997 and 1998, we used electrofishing to sample fish assemblages from each stream. Each of the landscape factors was significantly associated with fish assemblage structure and function based on analysis of covariance. Watershed storage was related to the greatest number of fish assemblage characteristics, but hydrogeopmorphic region and mature forest cover were strongly associated as well. The hydrogeomorphic region also mediated relationships between watershed character and fish assemblages. Discontinuity thresholds for our fish assemblages averaged 11% for watershed storage and 50% for watershed mature forest cover based on piecewise regression analysis. Although many of the landscape-fish relationships might have been manifest through effects on in-stream habitat, our results highlight the importance of management and land-use planning decisions at the watershed and landscape scales.

Animals↗

PubMed2004

Effect of human activities on overall trend of sedimentation in the lower Yellow River, China.

The Yellow River has been intensively affected by human activities, particularly in the past 50 years, including soil-water conservation in the upper and middle drainage basin, flood protection in the lower reaches, and flow regulation and water diversion in the whole drainage basin. All these changes may impact sedimentation process of the lower Yellow River in different ways. Assessing these impacts comprehensively is important for more effective environmental management of the drainage basin. Based on the data of annual river flow, sediment load, and channel sedimentation in the lower Yellow River between 1950 and 1997, the purpose of this paper is to analyze the overall trend of channel sedimentation rate at a time scale of 50 years, and its formative cause. It was found in this study that erosion control measures and water diversion have counteractive impacts on sedimentation rate in the lower Yellow River. Although both annual river flow and sediment decreased, there was no change in channel sedimentation rate. A regression analysis indicated that the sedimentation in the lower Yellow River decreased with the sediment input to the lower Yellow River but increased with the river flow input. In the past 30-40 years, the basin-wide practice of erosion and sediment control measures resulted in a decline in sediment supply to the Yellow River; at the same time, the human development of water resources that required river flow regulation and water diversion caused great reduction in river flow. The former may reduce the sedimentation in the lower Yellow River, but the reduction of river flow increased the sedimentation. When their effects counterbalanced each other, the overall trend of channel sedimentation in the lower Yellow River remained unchanged. This fact may help us to better understand the positive and negative effects of human activities in the Yellow River basin and to pay more attention to the negative effect of the development of water resources. The results of this study demonstrate that, if the overuse of river water cannot be controlled, the reduction of channel sedimentation in the lower Yellow River cannot be realized through the practice of erosion and sediment control measures.

China↗

PubMed2004

Use of radar remote sensing (RADARSAT) to map winter wetland habitat for shorebirds in an agricultural landscape.

Many of today's agricultural landscapes once held vast amounts of wetland habitat for waterbirds and other wildlife. Successful restoration of these landscapes relies on access to accurate maps of the wetlands that remain. We used C-band (5.6-cm-wavelength), HH-polarized radar remote sensing (RADARSAT) at a 38 degrees incidence angle (8-m resolution) to map the distribution of winter shorebird (Charadriiformes) habitat on agricultural lands in the Willamette Valley of western Oregon. We acquired imagery on three dates (10 December 1999, 27 January 2000, and 15 March 2000) and simultaneously collected ground reference data to classify radar signatures and evaluate map accuracy of four habitat classes: (1) wet with < or = 50% vegetation (considered optimal shorebird habitat), (2) wet with > 50% vegetation, (3) dry with < or = 50% vegetation, and (4) dry with > 50% vegetation. Overall accuracy varied from 45 to 60% among the three images, but the accuracy of focal class 1 was greater, ranging from 72 to 80%. Class 4 coverage was stable and dominated maps (40% of mapped study area) for all three dates, while coverage of class 3 decreased slightly throughout the study period. Among wet classes, class 1 was most abundant (about 30% coverage) in December and January, decreasing in March to approximately 15%. Conversely, class 2 increased dramatically from January to March, likely due to transition from class 1 as vegetation grew. This approach was successful in detecting optimal habitat for shorebirds on agricultural lands. For modest classification schemes, radar remote sensing is a valuable option for wetland mapping in areas where cloud cover is persistent.

Agriculture↗

PubMed2006

Dams in the Amazon: Belo Monte and Brazil's hydroelectric development of the Xingu River Basin.

Hydroelectric dams represent major investments and major sources of environmental and social impacts. Powerful forces surround the decision-making process on public investments in the various options for the generation and conservation of electricity. Brazil's proposed Belo Monte Dam (formerly Kararaô) and its upstream counterpart, the Altamira Dam (better known by its former name of Babaquara) are at the center of controversies on the decision-making process for major infrastructure projects in Amazonia. The Belo Monte Dam by itself would have a small reservoir area (440 km2) and large installed capacity (11, 181.3 MW), but the Altamira/Babaquara Dam that would regulate the flow of the Xingu River (thereby increasing power generation at Belo Monte) would flood a vast area (6140 km2). The great impact of dams provides a powerful reason for Brazil to reassess its current policies that allocate large amounts of energy in the country's national grid to subsidized aluminum smelting for export. The case of Belo Monte and the five additional dams planned upstream (including the Altamira/Babaquara Dam) indicate the need for Brazil to reform its environmental assessment and licensing system to include the impacts of multiple interdependent projects.

Brazil↗

PubMed2006

BR-319: Brazil's Manaus-Porto Velho highway and the potential impact of linking the arc of deforestation to central amazonia.

Brazil's BR-319 Highway linked Manaus, in the state of Amazonas, to Porto Velho, Rondônia, until it became impassable in 1988. Now it is proposed for reconstruction and paving, which would facilitate migration from the "Arc of Deforestation" in the southern part of the Amazon region to new frontiers farther north. The purpose of the highway, which is to facilitate transport to São Paulo of products from factories in the Manaus Free Trade Zone, would be better served by sending the containers by ship to the port of Santos. The lack of a land connection to Manaus currently represents a significant barrier to migration to central and northern Amazonia. Discourse regarding the highway systematically overestimates the highway's benefits and underestimates its impacts. A variety of changes would be needed prior to paving the highway if these potential impacts are to be attenuated. These include zoning, reserve creation, and increased governance in various forms, including deforestation licensing and control programs. More fundamental changes are also needed, especially the abandonment of the long-standing tradition in Brazil of granting squatters' rights to those who invade public land. Organizing Amazonian occupation in such a way that road construction and improvement cease to lead to explosive and uncontrolled deforestation should be a prerequisite for approval of the BR-319 and other road projects for which major impacts are expected. These projects could provide the impetus that is needed to achieve the transition away from appropriation of public land by both small squatters and by grileiros (large-scale illegal claimants). A delay in reconstructing the highway is advisable until appropriate changes can be effected.

Brazil↗

PubMed2006

Understanding the wicked nature of "unmanaged recreation" in Colorado's Front Range.

Unmanaged recreation presents a challenge to both researchers and managers of outdoor recreation in the United States because it is shrouded in uncertainty resulting from disagreement over the definition of the problem, the strategies for resolving the problem, and the outcomes of management. Incomplete knowledge about recreation visitors' values and relationships with one another, other stakeholders, and the land further complicate the problem. Uncertainty and social complexity make the unmanaged recreation issue a wicked problem. We describe the wickedness inherent in unmanaged recreation and some of the implications of wickedness for addressing the problem for the Front Range of the Rocky Mountains in Colorado. Conclusions about the nature of the problem are based on a problem appraisal that included a literature review and interviews of key informants. Addressing wickedness calls for institutional changes that allow for and reward the use of trust building, inclusive communication, and genuinely collaborative processes.

Colorado↗

PubMed2001

The aerobic physiology of the air-breathing blue gourami, Trichogaster trichopterus, necessitates behavioural regulation of breath-hold limits during hypoxic stress and predatory challenge.

Physiological characteristics of the blood oxygen transport system and muscle metabolism indicate a high dependence on aerobic pathways in the blue gourami, Trichogaster trichopterus. Haemoglobin concentration and haematocrit were modest and the blood oxygen affinity (P50=2.31 kPa at pH 7.4 and 28 degrees C) and its sensitivity to pH (Bohr factor, phi=-0.34) favour oxygen unloading at a relatively high oxygen pressure (PO2). The intracellular buffering capacity (44.0 slykes) and lactate dehydrogenase (LDH) activity (154.3 iu g(-1)) do not support exceptional anaerobic capabilities. Air-breathing frequency in the blue gourami is expected to increase when aquatic oxygen tensions decline. Under threat of predation, however, this behaviour must be modified at a potential cost to aerobic metabolism. We therefore tested the hypothesis that metabolic responses to predatory challenge and aquatic hypoxia are subject to behavioural modulation. Computer-generated visual stimuli consistently reduced air-breathing frequency at 19.95, 6.65 and 3.33 kPa PO2. Bi-directional rates of spontaneous activity were similarly reduced. The metabolic cost of this behaviour was estimated and positively correlated with PO2 but not with visual stimulation thus indicating down-regulation of spontaneous activity rather than breath-holding behaviour. Neither PO2 nor visual stimulation resulted in significant change to muscle lactate and ATP concentrations and confirm that aerobic breath-hold limits were maintained following behavioural modulation of metabolic demands.

Adaptation, Physiological↗

PubMed2002

Practical implementation of good practice in health, environment and safety management in enterprise in the Lodz region.

OBJECTIVES: Good practice in health, environment and safety management in enterprise (GP HESME) is the process that aims at continuous improvement in health, environment and safety performance, involving all stakeholders within and outside the enterprise. The GP HESME system is intended to function at different levels: international, national, local community, and enterprise. METHODS: The most important issues at the first stage of GP HESME implementation in the Lodz region are described. Also, the proposals of future activities in Lodz are presented. RESULTS: Practical implementation of GP HESME requires close co-operation among all stakeholders: local authorities, employers, employees, research institutions, and the state inspectorate. The WHO and the Nofer Institute of Occupational Medicine (NIOM) are initiating implementation, delivering professional consultation, education and training of stakeholders in the NIOM School of Public Health. The implementation of GP HESME in the Lodz region started in 1999 from a WHO meeting on criteria and indicators, followed by close collaboration of NIOM with the city's Department of Public Health. 'Directions of Actions for Health of Lodz Citizens' is now the city's official document that includes GP HESME as an important part of public health policy in Lodz. Several conferences were organized by NIOM together with the Professional Managers' Club, Labor Inspection, and the city's Department of Public Health to assess the most important needs of enterprises. The employers and managerial staff, who predominated among the participants, stated the need for tailored sets of indicators and economic appraisal of GP HESME activities. Special attention is paid to GP HESME in supermarkets and community-owned enterprises, e.g., a local transportation company. A special program for small- and medium-size enterprises will be the next step of GP HESME in the Lodz region. CONCLUSION: The implementation of GP HESME is possible if the efforts of local authorities; research institutions and state inspectorate are combined with the support of employers' organizations.

Environment Design↗

PubMed2004

Evaluation and visualisation of perceived thermal conditions.

Investigations have been made on ways to evaluate and visualise the perceived thermal climate. Thermal interaction with windows, heating, ventilation and seating influence the occupant's thermal situation. When this information on the physical thermal climate is linked together with human thermal sensation in "comfort-zone diagrams", valuable knowledge about the thermal situation can be visualised. Thermal manikin measurements of local climate disturbances with two different thermal manikins are found to be well correlated with the thermal sensation experienced by panels of subjects exposed to the same conditions. Differences both in manikin shape and construction, as well as testing conditions and panel members, make limit lines differ at some points. Comfort diagrams can be defined by equivalent temperature (t(eq)) limit lines; however, a consequence of individual and experimental variations is that it is not an optimal solution to have diagrams with absolute limit lines, rather a range of t(eq) values, forming new "comfort-zone diagrams". This improvement provides a more appropriate base for assessment of a complex local thermal climate, and opens up the possibility of a general profile that can be used with different manikins, possibly also different methods, in a variety of environments. However, more data from validation experiments with subjects and different methods will contribute to the development of a more general evaluation concept.

Air Conditioning↗

PubMed2004

Thermal sensation and comfort in transient non-uniform thermal environments.

Most existing thermal comfort models are applicable only to steady-state, uniform thermal environments. This paper presents summary results from 109 human tests that were performed under non-uniform and transient conditions. In these tests, local body areas were independently heated or cooled while the rest of the body was exposed to a warm, neutral or cool environment. Skin temperatures, core temperature, thermal sensation and comfort responses were collected at 1- to 3-min intervals. Based on these tests, we have developed predictive models of local and overall thermal sensation and comfort.

Air Conditioning↗

PubMed1997

Specialization in multi-agent systems through learning.

Specialization is a common feature in animal societies that leads to an improvement in the fitness of the team members and to an increase in the resources obtained by the team. In this paper we propose a simple reinforcement learning approach to specialization in an artificial multi-agent system. The system is composed of homogeneous and non-communicating agents. Because there is no communication, the number of agents in the team can easily scale up. Agents have the same initial functionalities, but they learn to specialize and so cooperate to achieve a complex gathering task efficiently. Simulation experiments show how the multi-agent system specializes appropriately so as to reach optimal (or near-to-optimal) performance in unknown and changing environments.

Animal Communication↗

PubMed2003

Causes and consequences of pedestrian injuries in children.

UNLABELLED: Pedestrian-car collisions are in motorised countries one of the leading causes of unintentional-injury-related death and morbidity among children. The objective of this study was to assess correlations between the mode and the severity or post-traumatic sequels of the injury. A 12-year (1989-2001) retrospective study of children aged 0-16 years injured in pedestrian-motor-vehicle collisions was undertaken. An anonymous survey with questionnaires completed by families was conducted. In this time period, 501 children (average age: 7.9 years) were injured. The lack of visibility of the vehicle (45%) and/or the pedestrian (39%) was the leading cause of injury. The mean injury severity score was 6.0 (1-75) and the mortality rate was 0.8% ( n=4, injury severity scores 47, 75, 75, 75). In this study, 217 questionnaires were analysed. When the children were injured, 37% of them were alone, 32.3% were in the presence of accompanying adults, and 24.0% were in the presence of other children. The latter group suffered the highest injury severity score ( P=0.016). Positive correlations were noted between injury severity score and impact speed ( r=0.31, P<0.001) and the distances that the children were thrown off or transported on the vehicle front ( r=0.29, P<0.001). Physical sequels were reported by 27% of the families, and 23% noted psychological disturbances. A positive correlation was noted between impact speed and the occurrence of physical sequels ( P<0.001). The number of deformed parts per vehicle was correlated to the occurrence of behavioural disturbances ( P<0.004). CONCLUSION: The incidence of post-traumatic sequels seems to be associated with higher speed at impact, lack of braking attempts, and higher numbers of vehicle parts deformed.

Accidents, Traffic↗

PubMed2007

Alteration in the GABAergic network of the prefrontal cortex in a potential animal model of psychosis.

The GABAergic input on cortical pyramidal cells has an important influence on the firing activity of the cortex and thus in regulating the behavioural outcome. The aim of the current study was to investigate the long-term neuroplastic adaptation of the GABAergic innervation pattern after an early severe systemic impact. Therefore 40 Mongolian gerbils (Meriones unguiculatus) were either reared under impoverished (IR) or enriched rearing conditions (ER) and received a single early (+)-methamphetamine (MA) challenge (50 mg/kg i.p.) or saline on postnatal day 14. The density of perisomatic immunoreactive GABAergic terminals surrounding layers III and V pyramidal neurons was quantified as well as the overall GABAergic fibre density in layers I/II and V of the medial prefrontal cortex (mPFC) of young adult animals (90 days). We found that IR in combination with an early MA administration led to a significant decrease in GABAergic bouton densities while the overall GABAergic fibre density increased in all investigated layers. The results indicate a shift in inhibition from somatic to dendritic innervation of pyramidal neurons in this potential animal model of psychosis. We conclude that IR combined with early MA trigger changes in the postnatal maturation of the prefrontal cortical GABAergic triggers innervation, which may interfere with proper signal processing within the prefrontal neural network.

Aging↗

PubMed2006

QSAR study of the enantiomeric excess in asymmetric catalytic reactions with topological indices and an artificial neural network.

The relationships between the enantiomer excess of product in catalytic asymmetric reactions and the structures of the catalysts or reagents in several asymmetric reactions were studied using a backpropagation (BP) neural network with topological indices and their chiral expansions. The trained network can be used to screen new asymmetric catalysts, estimate catalytic effects, design reaction environments, and prove or improve the proposed reaction mechanism.

Catalysis↗

PubMed2000

The response of adult human saphenous vein endothelial cells to combined pressurized pulsatile flow and cyclic strain, in vitro.

Adult human saphenous vein endothelial cells (HVEC) were cultured in a compliant tubular device and evaluated by Northern hybridization for the effects of combined pressurized pulsatile flow and cyclic strain on the expression of mRNAs for endothelin-1 (ET-1), endothelial cell nitric oxide synthase (ecNOS), tissue plasminogen activator (tPA), and plasminogen activator inhibitor type 1 (PAI-1). The hemodynamic environment was designed to mimic shear stress conditions at the distal anastomosis of a saphenous vein graft, a common site of intimal proliferation. Steady-state mRNA levels in experimental tubes were expressed relative to that in controls. No changes were observed in ET-1 mRNA after 1 and 24 hr, but a 50% decrease in experimental cultures was observed after 48 hr in the vascular simulating device. Similar results were obtained for ecNOS mRNA, although a subgroup (4 of 11) showed a significant decrease (>50%) by 24 hr. For tPA mRNA, no change was observed after 1 hr, but a significant decrease (>60%) was measured after 24 hr and no message was detectable after 48 hr. Steady-state levels for PAI-1 mRNA remained unchanged through 48 hr of treatment. These results show that pressure, pulsatile flow, and cyclic strain, when applied in concert, differentially alter vasoactive and fibrinolytic functions in HVEC. Moreover, the dramatic decrease in steady-state levels of tPA mRNA is consistent with a shift toward an increased thrombotic state.

Adult↗

PubMed2005

Floristics, performance and prognosis of historical trees in the urban forest of Guangzhou city (China).

Outstanding historical trees embedded in cities constitute pertinent environmental assets, yet they are widely threatened in third-world cities. Inadequate understanding of this valuable natural-cum-cultural heritage hinders proper conservation. A case study of Guangzhou in south China evaluated floristic composition, age profile and biomass structure of historical trees, assessed their performance in major habitats (institutional, park and roadside), and established a prognosis for future growth and management. The 348 historical trees examined belonged to only 25 species, vis-à-vis 254 trees in the entire urban forest, dominated by five species and native members. Roadside had more trees, followed by institutional and park, with merely the most common four species shared by all habitats. The limited commonality reflected tree-performance differentiation by habitats exerting selection pressure on species. The institutional growth-regime was more conducive to nurturing high-caliber specimens, whereas park is less capable. Individual species achievement by habitats, derived from tree-count ranking and relative-abundance indices, could inform species choice and tree conservation. Few trees exceeded 300 years of age in the millennium-old city, echoing a history of intense tree-city conflicts. Potential life-span, trunk and crown diameters indicated ample opportunities for further expansion of biomass and landscape impacts, which would be straitjacketed by the tightening urban fabric.

Biomass↗

PubMed2006

Biological integrity in mid-atlantic coastal plains headwater streams.

The objective of this study was to assess the applicability of using landscape variables in conjunction with water quality and benthic data to efficiently estimate stream condition of select headwater streams in the Mid-Atlantic Coastal Plains. Eighty-two streams with riffle sites were selected from eight-two independent watersheds across the region for sampling and analyses. Clustering of the watersheds by landscape resulted in three distinct groups (forest, crop, and urban) which coincided with watersheds dominant land cover or use. We used non-parametric analyses to test differences in benthos and water chemistry between groups, and used regression analyses to evaluate responses of benthic communities to water chemistry within each of the landscape groups. We found that typical water chemistry measures associated with urban runoff such as specific conductance and dissolved chloride were significantly higher in the urban group. In the crop group, we found variables commonly associated with farming such as nutrients and pesticides significantly greater than in the other two groups. Regression analyses demonstrated that the numbers of tolerant and facultative macroinvertebrates increased significantly in forested watersheds with small shifts in pollutants, while in human use dominated watersheds the intolerant macroinvertebrates were more sensitive to shifts in chemicals present at lower concentrations. The results from this study suggest that landscape based clustering can be used to link upstream landscape characteristics, water chemistry and biotic integrity in order to assess stream condition and likely cause of degradation without the use of reference sites. Notice: Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

Biodiversity↗