天柱山国内旅游市场空间结构分析与优化

从旅游客源和客流两方面分析了天柱山国内旅游市场的空间结构特征及其演化:2002年与1996年相比,天柱山国内旅游客源市场有扩散趋势,但仍呈较强的集中性,客源吸引半径小幅上升,呈明显的近程性;旅游客流在景区空间呈现多中心辐射扩散的分布点.在此基础上,划分了天柱山国内旅游市场空间圈层结构,对不同的圈层结构提出了不同的经营策略,以达到优化市场空间结构的目的.     

Logging injuries for a 10-year period in Jilin Province of the People's Republic of China

PROBLEM: Logging continues to be a major source of injuries in northeast China. This paper describes logging-related injuries in the Jilin Province of the People's Republic of China. METHODS: Logging fatalities and nonfatal injuries were summarized from 1981 to 1990 in Jilin. Injury data from 1991 for the entire forestry sector in China were also analyzed. RESULTS: Fatalities were mainly from of head injuries and were caused by being struck by an object. Nonfatal injuries were most often to the lower extremities and the head and were normally caused by being struck by an object or a fall or slip. The majority of both fatal and nonfatal logging injuries occurred to workers with less than 1 year of employment and those under 35 years old. Most injuries occurred November through March in Jilin. IMPACT ON INDUSTRY: Patterns of logging injury in Jilin of China were similar, but not identical, to those described in other studies of logging injuries worldwide. Methods found to be effective in reducing logging-related injuries in other parts of the world might be used in China to reduce the injuries associated with logging.     

Air pollution and agricultural aphid pests. II chamber filtration experiments

The responses of four major aphid pest species feeding on three major crops were studied in a series of experimental chambers on the roof of Imperial College in South Kensington, London. The experimental chambers were continually circulated with air which had been subjected to a variety of filtration treatments. In the first series of experiments there were three chambers subject to ambient air, charcoal-filtered air, and charcoal plus 'Purafil'-filtered air; in the subsequent experiments there were four chambers, a charcoal plus 'Purafil' plus charcoal treatment being added. These treatments provided a range of concentrations and mixtures of the ambient gases present at the site. The growth rate of aphids was measured both during filtration and post-filtration, the plants being exposed from sowing for either 42 or 84 days. In all cases there were significant effects on aphid performance which seemed to be most strongly linked to absolute and relative NO concentrations. The pattern of responses by the aphids accorded extremely well with those observed in closed-chamber fumigation experiments with stimulation of performance in relatively polluted air in all cases except Acyrthosiphon pisum (Harris) feeding on Vicia faba L. where the opposite effect was recorded.     

Changes in extreme events and the potential impacts on human health

Extreme weather and climate-related events affect human health by causing death, injury, and illness, as well as having large socioeconomic impacts. Climate change has caused changes in extreme event frequency, intensity, and geographic distribution, and will continue to be a driver for change in the future. Some of these events include heat waves, droughts, wildfires, dust storms, flooding rains, coastal flooding, storm surges, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local societal and environmental factors that affect disease burden. More information is needed about the impacts of climate change on public health and economies to effectively plan for and adapt to climate change. This paper describes some of the ways extreme events are changing and provides examples of the potential impacts on human health and infrastructure. It also identifies key research gaps to be addressed to improve the resilience of public health to extreme events in the future.

Implications: Extreme weather and climate events affect human health by causing death, injury, and illness, as well as having large socioeconomic impacts. Climate change has caused changes in extreme event frequency, intensity, and geographic distribution, and will continue to be a driver for change in the future. Some of these events include heat waves, droughts, wildfires, flooding rains, coastal flooding, surges, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local societal and environmental factors that affect disease burden.     

Reproductive biology of the commercial sea cucumber Holothuria fuscogilva in the Solomon Islands

 Reproduction of Holothuria fuscogilva (Selenka, 1867) in the Solomon Islands was investigated over a 4 yr period (1994 to 1998) by macroscopic and microscopic examination of the gonad tubules, the gonad index (GI) method, histological examination of gametogenesis, and spawning-induction trials. The gonad consisted of numerous tubules that dominated the coelom of gravid specimens. New tubules appeared in March, and grew in size and extent of branching until they reached their maximum size and maturity in August. Spawning occurred from August to October, with the majority of gametes released during October, although it was only partial in many individuals. After spawning, the tubules appeared wrinkled and resorbed into the gonad basis. A five-stage gonad maturity scale based on the macroscopic appearance of the gonad tubules corresponded with discrete stages of gametogenesis identified by histology. Gametogenesis was initiated in mid-March, with oogenesis and spermatogenesis occurring in parallel, followed by the growing stage (May to July) which was marked by active gamete development. Successful induction of spawning during the breeding period corroborated the GI and histological data. The uniform growth of gonad tubules indicated that H. fuscogilva in the Solomon Islands does not conform to the progressive tubule recruitment model described for other holothurians. An important application of this study is that the appearance of gonad tubules, removed by biopsy, can be used to determine the gonad condition of wild adults or captive broodstock. Received: 28 June 1999 / Accepted: 8 March 2000     

Feedback acceptance in developmental assessment centers: the role of feedback message,participant personality,and affective response to the feedback session

We investigated feedback acceptance by participants (N = 141) in an operational developmental assessment center (AC). Consistent with predictions based on self‐enhancement theory and the Affective Infusion Model, results indicated that higher assessor ratings were associated with higher feedback acceptance, and this relationship was partially mediated by the participant's affective reaction to the feedback session. Participants' self‐ratings of their AC performance did not affect this relationship suggesting no support for our prediction based on self‐verification theory. We also investigated the role of participants' self‐ratings of agreeableness, extraversion, and emotional stability in feedback acceptance by testing specific moderated mediation hypotheses. Extraversion was related to feedback acceptance through the affective reaction to the feedback session. Agreeableness moderated the affective reaction to the feedback session and feedback acceptance relationship such that there was a strong relationship between affective reaction and feedback acceptance for highly agreeable participants, but no relationship for low agreeable individuals. For low agreeable individuals, there was a positive direct relationship between the assessor ratings and feedback acceptance which was not observed for highly agreeable individuals. The hypothesized role of emotional stability in predicting feedback acceptance was not supported. Implications for the delivery of feedback in developmental ACs are discussed in light of these findings. Copyright © 2008 John Wiley & Sons, Ltd.     

Benzene accumulation in horticultural crops

In this study apple, blackberry and cucumber crops were exposed to elevated levels of benzene under controlled conditions. Benzene was retained in fruits of all crops, but only accumulated in leaves of blackberries and apples. The retention by cucumber fruits is suggested to result from the longer pathway for the desorption of benzene as a consequence of their increased tissue depth compared to leaves. The process of accumulation in blackberry and apple leaves is unknown. The ingestion of benzene via the food-chain pathway on the basis of this study is concluded not to be significant.     

Ecological lessons from the Chernobyl accident

The Chernobyl nuclear accident in 1986 not only caused serious ecological problems in both the Ukraine and Belarus, which continue to the present day, but also contaminated a large part of the higher latitudes of the northern hemisphere. In this paper an overview is given of the latter problems in upland UK, where ecological problems still remain some 17 years after initial contamination. Following deposition of radiocaesium and radioiodine in May 1986, measurements of radioactivity in grass and soil indicated a rapidly declining problem as the radioiodine decayed and the radiocaesium became immobilised by attachment to clay particles. However, these studies, as well as the advice received by the Ministry of Agriculture, Fisheries and Food, were based on lowland agricultural soils, with high clay and low organic matter contents. The behaviour of radiocaesium in upland UK turned out to be dominated by high and persistent levels of mobility and bioavailability. This resulted in the free passage of radiocaesium through the food chain and into sheep. Consequently the Ministry banned the sale and movement of sheep over large areas of upland Britain, with bans remaining on some farms to the present day. Present day predictions suggest that these bans will continue in some cases for some years to come. The causes of radiocaesium mobility in upland areas have subsequently been the subject of intense investigation centred around vegetation and, in particular, soil characteristics. Soil types were identified which were particularly vulnerable in this respect and, where these coincided with high levels of deposition, sheep bans tended to be imposed. While much of the earlier work suggested that a low clay content was the main reason for continuing mobility, a very high organic matter content is now also believed to play a major role, this being a characteristic of wet and acidic upland UK soils. The overall message from this affair is the importance of a fundamental understanding of biogeochemical pathways in different ecosystems when attempting to predict the impacts of large-scale contamination.