Identifying and mapping the protective forests of southeast Mt. Olympus as a tool for sustainable ecological and silvicultural planning, in a multi-purpose forest management framework

Rural development in forested lands and high altitude ecosystems created new regimes and disturbances that set protective function of forests as the most fundamental of all forest functions. Considering protective forests as engineering structures against natural hazards and risks, such as erosion, able to replace costly manmade infrastructures, a methodology is presenting aiming at their spatial identification in a changing mountainous environment. The methodology followed is based on field observations, calibrated models, topographical, geological and climatic data as well as human presence indicators combined properly in a GIS environment. Analysis showed that some forest soils are prone to erosion hazard unable to absorb disturbances like selective logging, revealing the protective role of their forest cover. The spatial identification of the forests with a particular protective function is the necessary step required for the design of a sustainable management of high elevated ecosystems.     

Assessment of possible ecological risks and hazards of transgenic fish with implications for other sexually reproducing organisms

Transgenic technology is developing rapidly; however, consumers and environmentalists remain wary of its safety for use in agriculture. Research is needed to ensure the safe use of transgenic technology and thus increase consumer confidence. This goal is best accomplished by using a thorough, unbiased examination of risks associated with agricultural biotechnology. In this paper, we review discussion on risk and extend our approach to predict risk. We also distinguish between the risk and hazard of transgenic organisms in natural environments. We define transgene risk as the probability a transgene will spread into natural conspecific populations and define hazard as the probability of species extinction, displacement, or ecosystem disruption given that the transgene has spread. Our methods primarily address risk relative to two types of hazards: extinction which has a high hazard, and invasion which has an unknown level of hazard, similar to that of an introduced exotic species. Our method of risk assessment is unique in that we concentrate on the six major fitness components of an organism's life cycle to determine if transgenic individuals differ in survival or reproductive capacity from wild type. Our approach then combines estimates of the net fitness parameters into a mathematical model to determine the fate of the transgene and the affected wild population. We also review aspects of fish ecology and behavior that contribute to risk and examine combinations of net fitness parameters which can lead to invasion and extinction hazards. We describe three new ways that a transgene could result in an extinction hazard: (1) when the transgene increases male mating success but reduces daily adult viability, (2) when the transgene increases adult viability but reduces male fertility, and (3) when the transgene increases both male mating success and adult viability but reduces male fertility. The last scenario is predicted to cause rapid extinction, thus it poses an extreme risk. Although we limit our discussion to aquacultural applications, our methods can easily be adapted to other sexually reproducing organisms with suitable adjustments of terminology.     

海南岛生态环境脆弱性评价

基于SOPAC和UNEP所建立的环境脆弱性评价方法,从风险、抵抗力、损害与退化3个方面构建了指标体系和综合指数,对海南岛生态环境脆弱性进行了评价.结果表明：海南岛的生态环境风险处于中等水平,其风险主要源于高强度的人类活动,包括强化农业、大众旅游业、采矿业以及岛上居民和游客所排放的大量固体废弃物等;较大的土地面积、较大的海拔变化幅度、完整的地理板块及丰富的生境类型等自然地理特征,赋予了海南岛较强的生态环境风险抵抗力,但受历史上人为和自然风险的累积影响,海南岛生态系统的损害与退化已较为严重,主要体现在土地退化和生物多样性的丧失等方面;综合考虑风险、抵抗力和损害与退化三方面因素,海南岛生态环境综合脆弱性处于中等水平,部分指标表现出很低的脆弱性,但另一些指标却表现出很高的脆弱性.     

Bioavailability of Metals in Soil and Health Risk Assessment for Populations Near an Indian Chromite Mine Area

Soils contaminated with toxic metals may be environmental hazards and sources of exposure to human population. Soils in mining areas are among the most heavily contaminated by metals from the mining activity. This study was focused on metals of interest in bioavailability studies using single and sequential extraction methods. Results of geochemical fractionation suggest that changes in soil characteristics may enhance the mobilization of Cu, Cr, Zn, and Al. The observed metals’ availability pattern was Cr > Cu > Zn > Al. However, the pattern of total contents of metals in soils was Al > Cr > Zn > Cu. Risks to human adults and children from selected metals through soil ingestion was assessed in terms of incremental lifetime average daily dose (LADD), hazard quotient (HQ), and hazard index (HI). The estimated LADDs and HI were within acceptable reference doses and less than 1, respectively, indicating low risk to human populations from the studied metals through soil ingestion in the studied mine area. The generated data may be useful in remediation of contaminated soils with metals.     

震后重建中的自然遗产保护——以都江堰市为例

自然遗产是人类的共同财富。在5．12汶川大地震的灾后重建过程中,不能忽视对自然遗产的保护和恢复。以都江堰市的灾后重建为例,探讨自然遗产的保护和恢复问题。首先,通过实地调查,了解都江堰市域的自然遗产受损状况,进行自然遗产地的地质灾害和生态脆弱性空间格局分析;在此基础上,针对自然遗产地的不同特点,提出了灾后重建的规划框架和可行措施。     

Occupational exposures and reproductive health: 2003 Teratology Society Meeting Symposium summary

Assuring reproductive health in the workplace challenges researchers, occupational safety and health practitioners, and clinicians. Most chemicals in the workplace have not been evaluated for reproductive toxicity. Although occupational exposure limits are established to protect 'nearly all' workers, there is little research that characterizes reproductive hazards. For researchers, improvements in epidemiologic design and exposure assessment methods are needed to conduct adequate reproductive studies. Occupational safety and health programs' qualitative and quantitative evaluations of the workplace for reproductive hazards may differ from standardized approaches used for other occupational hazards in that estimates of exposure intensity must be considered in the context of the time-dependent windows of reproductive susceptibility. Clinicians and counselors should place the risk estimate into context by emphasizing the limitations of the available knowledge and the qualitative nature of the exposure estimates, as well as what is known about other non-occupational risk factors for adverse outcomes. This will allow informed decision-making about the need for added protections or alternative duty assignment when a hazard cannot be eliminated. These policies should preserve a worker's income, benefits, and seniority. Applying hazard control technologies and hazard communication training can minimize a worker's risk. Chemical reproductive hazard training is required for workers by the Occupational Safety and Health Administration's Hazard Communication Standard. The National Institute for Occupational Safety and Health (NIOSH) has formed a National Occupational Research Agenda Team to promote communication and partnering among reproductive toxicologists, clinicians and epidemiologists, to improve reproductive hazard exposure assessment and management, and to encourage needed research.     

Interval mapping of quantitative trait loci for time-to-event data with the proportional hazards mixture cure model

Interval mapping using normal mixture models has been an important tool for analyzing quantitative traits in experimental organisms. When the primary phenotype is time-to-event, it is natural to use survival models such as Cox's proportional hazards model instead of normal mixtures to model the phenotype distribution. An extra challenge for modeling time-to-event data is that the underlying population may consist of susceptible and nonsusceptible subjects. In this article, we propose a semiparametric proportional hazards mixture cure model which allows missing covariates. We discuss applications to quantitative trait loci (QTL) mapping when the primary trait is time-to-event from a population of mixed susceptibility. This model can be used to characterize QTL effects on both susceptibility and time-to-event distribution, and to estimate QTL location. The model can naturally incorporate covariate effects of other risk factors. Maximum likelihood estimates for the parameters in the model as well as their corresponding variance estimates can be obtained numerically using an EM-type algorithm. The proposed methods are assessed by simulations under practical settings and illustrated using a real data set containing survival times of mice after infection with Listeria monocytogenes. An extension to multiple intervals is also discussed.     

Natural hazard threats to pollinators and pollination

Natural hazards are naturally occurring physical events that can impact human welfare both directly and indirectly, via shocks to ecosystems and the services they provide. Animal‐mediated pollination is critical for sustaining agricultural economies and biodiversity, yet stands to lose both from present exposure to natural hazards, and future climate‐driven shifts in their distribution, frequency, and intensity. In contrast to the depth of knowledge available for anthropogenic‐related threats, our understanding of how naturally occurring extreme events impact pollinators and pollination has not yet been synthesized. We performed a systematic review and meta‐analysis to examine the potential impacts of natural hazards on pollinators and pollination in natural and cultivated systems. From a total of 117 studies (74% of which were observational), we found evidence of community and population‐level impacts to plants and pollinators from seven hazard types, including climatological (extreme heat, fire, drought), hydrological (flooding), meteorological (hurricanes), and geophysical (volcanic activity, tsunamis). Plant and pollinator response depended on the type of natural hazard and level of biological organization observed; 19% of cases reported no significant impact, whereas the majority of hazards held consistent negative impacts. However, the effects of fire were mixed, but taxa specific; meta‐analysis revealed that bee abundance and species richness tended to increase in response to fire, differing significantly from the mainly negative response of Lepidoptera. Building from this synthesis, we highlight important future directions for pollination‐focused natural hazard research, including the need to: (a) advance climate change research beyond static “mean‐level” changes by better incorporating “shock” events; (b) identify impacts at higher levels of organization, including ecological networks and co‐evolutionary history; and (c) address the notable gap in crop pollination services research—particularly in developing regions of the world. We conclude by discussing implications for safeguarding pollination services in the face of global climate change.     

Hazard Ranking Methodology for Assessing Health Impacts of Unconventional Natural Gas Development and Production: The Maryland Case Study

The recent growth of unconventional natural gas development and production (UNGDP) has outpaced research on the potential health impacts associated with the process. The Maryland Marcellus Shale Public Health Study was conducted to inform the Maryland Marcellus Shale Safe Drilling Initiative Advisory Commission, State legislators and the Governor about potential public health impacts associated with UNGDP so they could make an informed decision that considers the health and well-being of Marylanders. In this paper, we describe an impact assessment and hazard ranking methodology we used to assess the potential public health impacts for eight hazards associated with the UNGDP process. The hazard ranking included seven metrics: 1) presence of vulnerable populations (e.g. children under the age of 5, individuals over the age of 65, surface owners), 2) duration of exposure, 3) frequency of exposure, 4) likelihood of health effects, 5) magnitude/severity of health effects, 6) geographic extent, and 7) effectiveness of setbacks. Overall public health concern was determined by a color-coded ranking system (low, moderately high, and high) that was generated based on the overall sum of the scores for each hazard. We provide three illustrative examples of applying our methodology for air quality and health care infrastructure which were ranked as high concern and for water quality which was ranked moderately high concern. The hazard ranking was a valuable tool that allowed us to systematically evaluate each of the hazards and provide recommendations to minimize the hazards.     

Genotoxic effects in wild rodents (Rattus rattus and Mus musculus) in an open coal mining area

Coal is a mixture of a variety of compounds containing mutagenic and carcinogenic polycyclic aromatic hydrocarbons. Exposure to coal is considered as an important non-cellular and cellular source of reactive oxygen species that can induce DNA damage. In addition, spontaneous combustion can occur in coal mining areas, further releasing compounds with detrimental effects on the environment. In this study the comet assay was used to investigate potential genotoxic effects of coal mining activities in peripheral blood cells of the wild rodents Rattus rattus and Mus musculus. The study was conducted in a coal mining area of the Municipio de Puerto Libertador, South West of the Departamento de Cordoba, Colombia. Animals from two areas in the coal mining zone and a control area located in the Municipio de Lorica were investigated. The results showed evidence that exposure to coal results in elevated primary DNA lesions in blood cells of rodents. Three different parameters for DNA damage were assessed, namely, DNA damage index, migration length and percentage damaged cells. All parameters showed statistically significantly higher values in mice and rats from the coal mining area in comparison to the animals from the control area. The parameter "DNA Damage Index" was found to be most sensitive and to best indicate a genotoxic hazard. Both species investigated were shown to be sensitive indicators of environmental genotoxicity caused by coal mining activities. In summary, our study constitutes the first investigation of potential genotoxic effects of open coal mining carried out in Puerto Libertador. The investigations provide a guide for measures to evaluate genotoxic hazards, thereby contributing to the development of appropriate measures and regulations for more careful operations during coal mining.     

Temporal quota corrections based on timing of harvest in a small game species

Theoretical models have shown that the effect of removing a given proportion of the population can be profoundly different if the harvest takes place late in the season compared to early. We explore the effect of these differences using theoretical models based on the concept of demographic value and empirical data on seasonal patterns of natural mortality risk in two contrasting populations of willow ptarmigan in Norway. Based on the theoretical models, we found that changes in the timing of harvest have a much stronger effect in populations with relatively low annual survival compared to populations characterized by longevity typical for species with slow life histories. Also, the timing of harvest is more influential in cases with constant mortality hazards compared to a situation with density-dependent natural mortality. Empirical data from two study populations of willow ptarmigan showed large deviations from the theoretical predictions of models with both constant and density-dependent mortality hazards. There were also large differences in both the temporal pattern and magnitude of annual survival between the two ptarmigan populations (54 vs 26% annual survival). Site differences illustrate the importance of knowledge of both the magnitude and temporal pattern of natural mortality hazard to be able to correctly predict the effect of changing the timing of harvest in a population. In the two ptarmigan populations, we show how harvest quotas can be adjusted in accordance to the empirical estimates of natural mortality risk and how this determines the effects of shifting from harvesting early to late in the annual cycle.     

Phytoremediation for lightly toxic sites: Hazard perception and acceptance of remediation alternatives

Individuals perceive environmental hazards based on their own knowledge and experience. While much research has been conducted to examine the factors affecting hazard perceptions, there is a lack of understanding about the particular contexts or factors that influence public acceptance of hazard mitigation alternatives. Without this knowledge, expert groups cannot effectively communicate with the public and help them consider the use of emerging technologies to alleviate hazardous conditions. This study investigates the influence of perceived pollution hazard levels in abandoned industrial sites as well as knowledge levels of stakeholder groups on the acceptance of different types of remediation strategies. I compare local residents' perceptions with those of graduate students majoring in landscape architecture. The study results found that lower hazard levels were associated with a higher acceptance of on-site natural attenuation, the so-called phytoremediation, with students being significantly more likely to favor this option than residents. These results imply that the social acceptability of remediation technologies, including phytotechnology, is context dependent and can vary significantly depending on the hazard status of the site and the knowledge base of the stakeholder group.     

Spatiotemporal assessment of rainstorm hazard risk in Qinling mountains of China

Rainstorms are natural hazards, and they create hurdles in many parts of the world. They often cause damages to the life, properties, and human activities. The Qinling Mountains of China are among the few areas that are extremely hit by the rainstorms, but their hazard risks have not fully been assessed. This article takes an attempt to fill this gap by providing a comprehensive spatiotemporal risk assessment for the area. By using the geographic information system-enhanced Analytical Hierarchy Process assessment framework and the comprehensive index model, the rainstorm hazard risks can be evaluated from four different aspects. At last, the comprehensive rainstorm hazard risks have been assessed and zoned. Results indicate that with regional climate change, the frequencies of rainstorm have slightly increased over the past period of 46 years, and rainstorm hazard risks become higher on the whole. As a strong seasonal variation in the rainstorm days, the highest rainstorm hazard risks occur in July annually. The comprehensive rainstorm hazard risks in the southern regions of the Qinling Mountains are obviously higher than those in the northern regions. The Hanzhong and Ankang basins along the Hanjiang River are under the highest risk of rainstorms. The big cities of Xi'an and Baoji, piedmont plain and regions with good transportation, are under the lowest risk. The spatial distribution of rainstorm hazard risk shows that it has certain regulations along the rivers, ridges, and valleys, but it may be affected by the factors of rainfall and human activities. This article is significant for strategic environmental planning and hazard emergency management of the study area as well as in similar climatic regions of the world.     

Marginal hazard ratio estimates in joint frailty models for heart failure trials

This work is motivated by clinical trials in chronic heart failure disease, where treatment has effects both on morbidity (assessed as recurrent non‐fatal hospitalisations) and on mortality (assessed as cardiovascular death, CV death). Recently, a joint frailty proportional hazards model has been proposed for these kind of efficacy outcomes to account for a potential association between the risk rates for hospital admissions and CV death. However, more often clinical trial results are presented by treatment effect estimates that have been derived from marginal proportional hazards models, that is, a Cox model for mortality and an Andersen–Gill model for recurrent hospitalisations. We show how these marginal hazard ratios and their estimates depend on the association between the risk processes, when these are actually linked by shared or dependent frailty terms. First we derive the marginal hazard ratios as a function of time. Then, applying least false parameter theory, we show that the marginal hazard ratio estimate for the hospitalisation rate depends on study duration and on parameters of the underlying joint frailty model. In particular, we identify parameters, for example the treatment effect on mortality, that determine if the marginal hazard ratio estimate for hospitalisations is smaller, equal or larger than the conditional one. How this affects rejection probabilities is further investigated in simulation studies. Our findings can be used to interpret marginal hazard ratio estimates in heart failure trials and are illustrated by the results of the CHARM‐Preserved trial (where CHARM is the ‘Candesartan in Heart failure Assessment of Reduction in Mortality and morbidity’ programme).     

HIV-1 Superinfection Occurs Less Frequently Than Initial Infection in a Cohort of High-Risk Kenyan Women

HIV superinfection (reinfection) has been reported in several settings, but no study has been designed and powered to rigorously compare its incidence to that of initial infection. Determining whether HIV infection reduces the risk of superinfection is critical to understanding whether an immune response to natural HIV infection is protective. This study compares the incidence of initial infection and superinfection in a prospective seroincident cohort of high-risk women in Mombasa, Kenya. A next-generation sequencing-based pipeline was developed to screen 129 women for superinfection. Longitudinal plasma samples at <6 months, >2 years and one intervening time after initial HIV infection were analyzed. Amplicons in three genome regions were sequenced and a median of 901 sequences obtained per gene per timepoint. Phylogenetic evidence of polyphyly, confirmed by pairwise distance analysis, defined superinfection. Superinfection timing was determined by sequencing virus from intervening timepoints. These data were combined with published data from 17 additional women in the same cohort, totaling 146 women screened. Twenty-one cases of superinfection were identified for an estimated incidence rate of 2.61 per 100 person-years (pys). The incidence rate of initial infection among 1910 women in the same cohort was 5.75 per 100pys. Andersen-Gill proportional hazards models were used to compare incidences, adjusting for covariates known to influence HIV susceptibility in this cohort. Superinfection incidence was significantly lower than initial infection incidence, with a hazard ratio of 0.47 (CI 0.29–0.75, p = 0.0019). This lower incidence of superinfection was only observed >6 months after initial infection. This is the first adequately powered study to report that HIV infection reduces the risk of reinfection, raising the possibility that immune responses to natural infection are partially protective. The observation that superinfection risk changes with time implies a window of protection that coincides with the maturation of HIV-specific immunity.     

Competing risks regression for stratified data

For competing risks data, the Fine-Gray proportional hazards model for subdistribution has gained popularity for its convenience in directly assessing the effect of covariates on the cumulative incidence function. However, in many important applications, proportional hazards may not be satisfied, including multicenter clinical trials, where the baseline subdistribution hazards may not be common due to varying patient populations. In this article, we consider a stratified competing risks regression, to allow the baseline hazard to vary across levels of the stratification covariate. According to the relative size of the number of strata and strata sizes, two stratification regimes are considered. Using partial likelihood and weighting techniques, we obtain consistent estimators of regression parameters. The corresponding asymptotic properties and resulting inferences are provided for the two regimes separately. Data from a breast cancer clinical trial and from a bone marrow transplantation registry illustrate the potential utility of the stratified Fine-Gray model.     

Multivariate survival analysis for case-control family data

Multivariate survival data arise from case-control family studies in which the ages at disease onset for family members may be correlated. In this paper, we consider a multivariate survival model with the marginal hazard function following the proportional hazards model. We use a frailty-based approach in the spirit of Glidden and Self (1999) to account for the correlation of ages at onset among family members. Specifically, we first estimate the baseline hazard function nonparametrically by the innovation theorem, and then obtain maximum pseudolikelihood estimators for the regression and correlation parameters plugging in the baseline hazard function estimator. We establish a connection with a previously proposed generalized estimating equation-based approach. Simulation studies and an analysis of case-control family data of breast cancer illustrate the methodology's practical utility.     

A marginal mixed baseline hazards model for multivariate failure time data

In multivariate failure time data analysis, a marginal regression modeling approach is often preferred to avoid assumptions on the dependence structure among correlated failure times. In this paper, a marginal mixed baseline hazards model is introduced. Estimating equations are proposed for the estimation of the marginal hazard ratio parameters. The proposed estimators are shown to be consistent and asymptotically Gaussian with a robust covariance matrix that can be consistently estimated. Simulation studies indicate the adequacy of the proposed methodology for practical sample sizes. The methodology is illustrated with a data set from the Framingham Heart Study.     

Oral toxicity of p-aminopropiophenone to brushtail possums (Trichosurus vulpecula), dama wallabies (Macropus eugenii), and mallards (Anas platyrhynchos)

Development of p-aminopropiophenone (PAPP) as a toxicant for pest predator management in New Zealand and Australia prompted investigation of its toxicity to potential nontarget species. Acute oral toxicity of PAPP in brushtail possums (Trichosurus vulpecula), dama wallabies (Macropus eugenii), and Mallards (Anas platyrhynchos) was estimated in pen trials, carried out between February 2000 and September 2001. The susceptibility of possums (LD50>or=500 mg kg(-1)) and wallabies (LD50 89 mg kg(-1)) to PAPP was low in comparison to noncarnivorous placental mammal species, but ducks (LD50 38 mg kg(-1)) were more susceptible than other bird species. These results suggest that the nontarget hazard to possums and wallabies from PAPP bait applied for pest predator control would be low. However, future development of PAPP as a vertebrate pest control agent should include rigorous assessments of the hazard posed by bait formulations to bird species and provision for delivery techniques that could mitigate exposure of nontarget birds.     

Wildlife hazard assessment for Phoenix Sky Harbor International Airport

We examined wildlife abundance, distribution, and movement patterns at Phoenix Sky Harbor International Airport (PHX) and within an 8-km radius to assess current air-strike hazards, and to provide baseline information for projecting changes in air-strike hazards as land-use patterns around PHX change. We found that water sources at or near PHX especially induced wildlife movement patterns that put air traffic at risk. This was particularly true of the Salt River bed adjacent to the airport, which also is a natural flight corridor for birds. Compounding the problem, air traffic at PHX was the heaviest when bird abundance and activity was the greatest during migration and breeding. We feel that air strike hazards at PHX are likely to increase substantially as the Salt River bed is reclaimed to produce additional lakes and high quality riparian habitat. We offer recommendations to reduce the hazard levels currently found at PHX and to reduce additional hazards as the habitat around PHX is converted and produces more attractive wildlife habitat.