116 research outputs found

    The Influence of Land Use/Land Cover on Climatological Values of the Diurnal Temperature Range

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    The diurnal temperature range (DTR) at weather observation stations that make up the U.S. Historical Climatology Network was evaluated with respect to the predominant land use/land cover associated with the stations within three radii intervals (100, 1000, and 10 000 m) of the stations. Those stations that were associated with predominantly rural land use/land cover (LULC) usually displayed the greatest observed DTR, whereas those associated with urban related land use or land cover displayed the least observed DTR. The results of this study suggest that significant differences in the climatological DTR were observed and could be attributed to the predominant LULC associated with the observation stations. The results also suggest that changes in the predominant LULC conditions, within as great as a 10 000 m radius of an observation station, could significantly influence the climatological DTR. Future changes in the predominant LULC associated with observation sites should be monitored similar to the current practice of monitoring changes in instruments or time of observation at the observations sites

    Pharmacotherapy and pregnancy: Highlights from the first International Conference for Individualized Pharmacotherapy in Pregnancy

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    Data are sparse on the effects of medication use during pregnancy. Half of the world's population is women. The majority of women become pregnant, and many of those women take some kind of medication during their pregnancy, even if only for a short time. The majority of drugs have not been rigorously studied in pregnant women to determine the most effective dose with the least potential for adverse effects. Instead, women are given “cookie‐cutter” therapy, using doses extrapolated from nonpregnant women, men, or pregnant animals. This can lead to problems. Instead, individualization of pharmacotherapy in pregnancy promises to take individual women and determine the optimal dose and drug for them to maximize the effect of the drug while attempting to minimize the side effects to them and their unborn babies. Because this field of study is underrepresented, we held a conference to bring together researchers and experts to discuss current knowledge, issues, and challenges surrounding individualized pharmacotherapy in pregnancy. Speakers came from the NIH, the Food and Drug Administration (FDA), and various research centers in the United States and Canada. Below are the summaries of the discussions at the conference. Full notes from the panel discussions are available from the authors on request

    Hot mix asphalt (HMA) characterization for the 2002 AASHTO design guide.

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    The two study objectives were to conduct dynamic modulus and APA rutting tests of selected Mississippi HMA mixtures. A total of twenty-five mixtures were tested including aggregate combinations of gravel and gravel/limestone; 9.5mm, 12.5mm and 19.0mm NMAS gradations; asphalt binder grades of PG 67-22, PG 76-22 and 82-22; and compaction Ndesign levels of 50, 65 and 85. Twenty-four of the mixtures were designed for four percent air voids and one was designed for three percent air voids. Sample preparation proved to be problematic. Target air void content for the dynamic modulus samples was 7.0\ub10.5 percent. Results (air voids) for a given compaction level can vary with gradation, aggregate type, asphalt content and mass of mix compacted. Another problem is the density gradient of Superpave gyratory compacted cylindrical samples. Developers of the test method minimized the density gradient by cutting a 100mm core from the larger, original 150mm sample. To achieve the target air void content of 7.0\ub10.5 percent for cored dynamic modulus test specimens, the 150mm samples were compacted to an air void level of approximately 8.0\ub10.5 percent. Because of uncertainty in the air void level that would be produced, four to five 150mm samples of a mixture were compacted with a goal of producing three with the target air void level. The cored 100 mm diameter test specimens were checked that the target 7.0\ub10.5 percent air void level was achieved. In some cases, new samples and cored specimens had to be prepared with an adjusted air void level. After compaction, specimen preparation for dynamic modulus testing requires fixtures, coring equipment and saw rugged enough to produce specimens meeting required geometric tolerances. Some end spalling during sawing was largely stopped by wrapping duct tape around the specimen's ends. Results of the study were parameters of the fitted sigmoid functions and associated shift factors of the master curve for twenty-fine HMA mixtures. MDOT will use these functions to estimate HMA dynamic modulus as input for calibrating the 2002 pavement design guide. Asphalt Pavement Analyzer rutting test results for the twenty-five mixtures are compared with MDOT rutting criteria

    Empirical Models of Transitions between Coral Reef States: Effects of Region, Protection, and Environmental Change

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    There has been substantial recent change in coral reef communities. To date, most analyses have focussed on static patterns or changes in single variables such as coral cover. However, little is known about how community-level changes occur at large spatial scales. Here, we develop Markov models of annual changes in coral and macroalgal cover in the Caribbean and Great Barrier Reef (GBR) regions

    Consistent Pattern of Local Adaptation during an Experimental Heat Wave in a Pipefish-Trematode Host-Parasite System

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    Extreme climate events such as heat waves are expected to increase in frequency under global change. As one indirect effect, they can alter magnitude and direction of species interactions, for example those between hosts and parasites. We simulated a summer heat wave to investigate how a changing environment affects the interaction between the broad-nosed pipefish (Syngnathus typhle) as a host and its digenean trematode parasite (Cryptocotyle lingua). In a fully reciprocal laboratory infection experiment, pipefish from three different coastal locations were exposed to sympatric and allopatric trematode cercariae. In order to examine whether an extreme climatic event disrupts patterns of locally adapted host-parasite combinations we measured the parasite's transmission success as well as the host's adaptive and innate immune defence under control and heat wave conditions. Independent of temperature, sympatric cercariae were always more successful than allopatric ones, indicating that parasites are locally adapted to their hosts. Hosts suffered from heat stress as suggested by fewer cells of the adaptive immune system (lymphocytes) compared to the same groups that were kept at 18°C. However, the proportion of the innate immune cells (monocytes) was higher in the 18°C water. Contrary to our expectations, no interaction between host immune defence, parasite infectivity and temperature stress were found, nor did the pattern of local adaptation change due to increased water temperature. Thus, in this host-parasite interaction, the sympatric parasite keeps ahead of the coevolutionary dynamics across sites, even under increasing temperatures as expected under marine global warming

    Effects of Extreme Precipitation to the Distribution of Infectious Diseases in Taiwan, 1994–2008

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    The incidence of extreme precipitation has increased with the exacerbation of worldwide climate disruption. We hypothesize an association between precipitation and the distribution patterns that would affect the endemic burden of 8 infectious diseases in Taiwan, including water- and vector-borne infectious diseases. A database integrating daily precipitation and temperature, along with the infectious disease case registry for all 352 townships in the main island of Taiwan was analysed for the period from 1994 to 2008. Four precipitation levels, <130 mm, 130–200 mm, 200–350 mm and >350 mm, were categorized to represent quantitative differences, and their associations with each specific disease was investigated using the Generalized Additive Mixed Model and afterwards mapped on to the Geographical Information System. Daily precipitation levels were significantly correlated with all 8 mandatory-notified infectious diseases in Taiwan. For water-borne infections, extreme torrential precipitation (>350 mm/day) was found to result in the highest relative risk for bacillary dysentery and enterovirus infections when compared to ordinary rain (<130 mm/day). Yet, for vector-borne diseases, the relative risk of dengue fever and Japanese encephalitis increased with greater precipitation only up to 350 mm. Differential lag effects following precipitation were statistically associated with increased risk for contracting individual infectious diseases. This study’s findings can help health resource sector management better allocate medical resources and be better prepared to deal with infectious disease outbreaks following future extreme precipitation events

    Patterns and Perceptions of Climate Change in a Biodiversity Conservation Hotspot

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    Quantifying local people's perceptions to climate change, and their assessments of which changes matter, is fundamental to addressing the dual challenge of land conservation and poverty alleviation in densely populated tropical regions To develop appropriate policies and responses, it will be important not only to anticipate the nature of expected changes, but also how they are perceived, interpreted and adapted to by local residents. The Albertine Rift region in East Africa is one of the world's most threatened biodiversity hotspots due to dense smallholder agriculture, high levels of land and resource pressures, and habitat loss and conversion. Results of three separate household surveys conducted in the vicinity of Kibale National Park during the late 2000s indicate that farmers are concerned with variable precipitation. Many survey respondents reported that conditions are drier and rainfall timing is becoming less predictable. Analysis of daily rainfall data for the climate normal period 1981 to 2010 indicates that total rainfall both within and across seasons has not changed significantly, although the timing and transitions of seasons has been highly variable. Results of rainfall data analysis also indicate significant changes in the intra-seasonal rainfall distribution, including longer dry periods within rainy seasons, which may contribute to the perceived decrease in rainfall and can compromise food security. Our results highlight the need for fine-scale climate information to assist agro-ecological communities in developing effective adaptive management

    Climate Change Challenge (3C) and Social-Economic-Ecological Interface-Building—Exploring Potential Adaptation Strategies for Bio-resource Conservation and Livelihood Development: Epilogue

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    Climate change is arguably the single most dominant environmental threat facing humanity. Its manifestations, particularly through rising temperatures, changing rainfall, sea-level rise and increasing droughts and floods have the potential to adversely impact natural ecosystems (such as forests, grasslands, rivers and oceans) and socioeconomic systems (such as food production, fisheries and coastal settlements). This is adding additional stresses to the ecosystem services which form a substantial source of income to the rural inhabitants. It is most proximate and inextricably linked to well-being, development and economic growth which are part of the eight Millennium Development Goals (MDGs), which ran from 2000 to 2015
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