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At least 919 records · Page 51Linked to original sources
PubMed2006

An ecological risk assessment of Cry1F maize pollen impact to pale grass blue butterfly.

The intrinsic toxicity of lepidopteran-active Bt proteins necessitates assessment of non-target risks associated with environmental release of transgenic crops expressing these proteins. Principles of ecological risk assessment provide a means for assessing non-target risks when information regarding exposure to the toxin and species-specific effects are lacking. This is shown for the case of Bt Cry1F maize release in Japan, where off-field pollen dissemination and effect on butterfly species is of concern. The specific ecological entity of concern for the assessment of the non-target impact of Cry1F maize pollen was Yamato-shijimi (pale grass blue butterfly), Pseudozizeeria maha (Kollar), a commonly occurring, susceptible species. Yamato-shijimi is widely adapted in Japan where it occurs in both rural and metropolitan settings, corresponding to the distribution and habitat of katabami (Oxalis corniculata (L.)), the larval host plant. The northern extent of Yamato-shijimi habitat lies to the south of major maize production regions in Japan, but exposure may occur elsewhere where maize and Yamato-shijimi co-occur. Screening level assessment of potential adverse effects to Yamato-shijimi in the field environment considered the probability for spatial-temporal co-occurrence of the life stages of concern (1st and 2nd instars) and the stressor (Cry1F protein expressed in maize pollen) at environmentally relevant concentrations. In the event of exposure to maize pollen, early instars of Yamato-shijimi feed exclusively on the underside of katabami leaves, which further limits the portion of the butterfly population that would be exposed. Projected levels of exposure to Cry1F pollen are below the toxicity level of concern and, thus, indicate negligible risk. Most sensitive species characterization (intergenera sensitivity) similarly shows negligible risk to other Japanese butterfly species of concern when distributed beyond the maize field or field margin.

Animals↗
PubMed1995

[Spatial and age distribution of spermarche and its influence on development of male adolescents in China].

Spatial and age distribution of spermarche, and difference of growth and development in pre- and post-spermarcheal boys were analyzed based on the data of national physique and health surveillance for school children collected in 1991 to study the relationship between spermarche and development. Generally, there existed a trend that onset of spermarche was earlier in boys living in south China than in the north, and earlier in urban than in rural areas. Physique, physiological quality and sports performance were significantly better in post-spermarcheal boys aged 11 to 14 than in pre-spermarcheal ones. Discriminant analysis showed there were significant differences in development between pre- and post-spermercheal boys, especially in body height, weight, biacromial diameter, biiliocristal diameter and vital capacity, but there was no difference in type of body build.

Adolescent↗
PubMed2002

Using a geographical information system to map the distribution of dentists in Ohio.

BACKGROUND: Studies have reported that dental care is the highest unmet health care need in the United States and have evaluated this in terms of individual determinants of access and utilization. None of these studies took into consideration the provider issues of availability and accessibility or of spatial relations. The aim of this study was to analyze issues of provider availability and accessibility in Ohio using a geographical information system, or GIS. METHODS: Three Ohio databases were geocoded using GIS software. The databases included all 6,132 dentists licensed to practice in Ohio, 1,898 dentists who had billed the state Medicaid program in 1998 and safety-net clinics that provided free or low-cost care. Each practitioner was mapped at the county and ZIP code levels. RESULTS: Results are reported using maps at the county and ZIP code levels. The maps showed that 69.4 percent of dentists practiced in 12 metropolitan counties, 14 percent in 17 suburban counties and 16.6 percent in 59 rural counties (rural non-Appalachian counties plus Appalachian counties). In Appalachia, the dentist-to-population ratio was about one-half that of the metropolitan counties. CONCLUSION: Obvious disparities exist in the distribution of dentists in Ohio, particularly in rural and Appalachian counties. The need to increase the availability of dentists in these counties is evident. PRACTICE IMPLICATIONS: GIS is a useful tool for evaluating provider distribution and availability and planning programs to attract dentists to areas with small numbers of dentists.

Adult↗
PubMed1998

The relationship between population density and cancer mortality in Taiwan.

Many investigators have examined urbanization gradients in cancer rates. The purpose of this report was to identify urban-rural trends in cancer mortality rates (1982-1991) for municipalities in Taiwan. For this purpose, Taiwan's municipalities were classified as rural, suburban, urban, or metropolitan, using population density as an ordinal indicator of the degree of urbanization. Average annual age-adjusted, site-specific cancer mortality rates were calculated for both sexes within each population density group. Significant increasing trends with more urbanization were observed in mortality rates for cancers of the lung, pancreas, and kidney among both males and females, as well as male prostate cancer, and female breast and ovary cancer. In addition, this study revealed a significant rural excess for nonmelanoma skin cancer among both males and females, as well as male non-Hodgkin's lymphoma, and cancers of the female bone, and female connective tissue. Analytic studies for sites with consistent urban-rural trends may be fruitful in identifying the aspect of population density, or other unmeasured factors, that contribute to these trends.

Female↗
PubMedDate not supplied

[Space organization and structure of the scorpion population in the region of Sfax (Tunisia)].

Four species of scorpions live in Sfax area: Androctonus australis, Androctonus aeneas, Buthus occitanus and Scorpio maurus. Preliminary study of this community organization showed that: spatial segregation allow coexistence of different species, nature and texture of the soil determine biogeography distribution and populations abundances in the sector studied, populations of scorpions maintains close connections between them and with guild of insectivorous and nocturnal lizards, particularly competition and predation.

Animals↗
PubMed1999

Distribution of fluoride and fluorosis in Ethiopia and prospects for control.

A review and mapping of fluoride test data for 270 water sources in 126 communities and examination of the literature of fluorosis distribution in Ethiopia show that this health problem extends beyond the Rift Valley into some highland communities. Fluoride concentrations above 5.0 mg/l in the Rift Valley were found mostly in hot springs (100% of all sources), lakes (78%), shallow wells (54%) and boreholes (35%) and the lowest concentrations (below 1.5 mg/l) in springs and rivers. Analysis of hydrochemical, economic and demographic factors in the spatial distribution of high-fluoride domestic water sources indicates that the fluorosis problem has become more serious in the Rift Valley in recent decades. Considerable spatial variation in the occurrence of fluoride, even within the same communities, and the presence of some low-fluoride water sources in the Rift Valley offer possibilities for geochemical exploration for acceptable domestic sources. The defluoridation programme in the Wonji irrigation scheme illustrates the problems faced by a large rural community in a developing country. Possibilities for control are examined and recommendations made for the development of alternative water sources and promising defluoridation methods using locally available materials and technologies.

Environmental Exposure↗