Population density, water supply, and the risk of dengue fever in Vietnam: cohort study and spatial analysis.

BACKGROUND: Aedes aegypti, the major vector of dengue viruses, often breeds in water storage containers used by households without tap water supply, and occurs in high numbers even in dense urban areas. We analysed the interaction between human population density and lack of tap water as a cause of dengue fever outbreaks with the aim of identifying geographic areas at highest risk. METHODS AND FINDINGS: We conducted an individual-level cohort study in a population of 75,000 geo-referenced households in Vietnam over the course of two epidemics, on the basis of dengue hospital admissions (n = 3,013). We applied space-time scan statistics and mathematical models to confirm the findings. We identified a surprisingly narrow range of critical human population densities between around 3,000 to 7,000 people/km² prone to dengue outbreaks. In the study area, this population density was typical of villages and some peri-urban areas. Scan statistics showed that areas with a high population density or adequate water supply did not experience severe outbreaks. The risk of dengue was higher in rural than in urban areas, largely explained by lack of piped water supply, and in human population densities more often falling within the critical range. Mathematical modeling suggests that simple assumptions regarding area-level vector/host ratios may explain the occurrence of outbreaks. CONCLUSIONS: Rural areas may contribute at least as much to the dissemination of dengue fever as cities. Improving water supply and vector control in areas with a human population density critical for dengue transmission could increase the efficiency of control efforts. Please see later in the article for the Editors' Summary

Emerging technologies for reef fisheries research and management [held during the 56th annual Gulf and Caribbean Fisheries Institute meeting in Tortola, British Virgin Islands, November 2003]

This publication of the NOAA Professional Paper NMFS Series is the product of a special symposium on “Emerging Technologies for Reef Fisheries Research and Management” held during the 56th annual Gulf and Caribbean Fisheries Institute meeting in Tortola, British Virgin Islands, November 2003. The purpose of this collection is to highlight the diversity of questions and issues in reef fisheries management that are benefiting from applications of technology. Topics cover a wide variety of questions and issues from the study of individual behavior, distribution and abundance of groups and populations, and associations between habitats and fish and shellfish species.(PDF files contains 124 pages.

Linking socioeconomic factors to mosquito control in residential Washington, D.C.

Urban larval mosquito control strategies include elimination of aboveground water-holding containers by private residents (`source reduction') and larviciding of belowground storm drains and utility manholes. Effective source reduction is dependent on public education campaigns that identify key sources of mosquitoes, target at-risk neighborhoods, and create an informed and motivated citizenry. I conducted 242 yard surveys for mosquito larval habitats paired with Knowledge, Attitude, and Practice (KAP) questionnaires administered to residents in six socioeconomically-diverse neighborhoods in the greater Washington, D.C. metropolitan area, and sampled 201 belowground habitats adjacent to these households. In chapter 2, I analyze associations between resident socioeconomic status, knowledge, attitudes, practices and mosquito indices. In chapter 3, I examine variations in larval habitat quality, quantity and type across neighborhoods of differing socioeconomic status. In chapter 4, I compare larval populations in aboveground and belowground habitats. The implications for educational literature and mosquito management are discussed

Annual Report: 2009

I submit herewith the annual report from the Agricultural and Forestry Experiment Station, School of Natural Resources and Agricultural Sciences, University of Alaska Fairbanks, for the period ending December 31, 2009. This is done in accordance with an act of Congress, approved March 2, 1887, entitled, “An act to establish agricultural experiment stations, in connection with the agricultural college established in the several states under the provisions of an act approved July 2, 1862, and under the acts supplementary thereto,” and also of the act of the Alaska Territorial Legislature, approved March 12, 1935, accepting the provisions of the act of Congress. The research reports are organized according to our strategic plan, which focuses on high-latitude soils, high-latitude agriculture, natural resources use and allocation, ecosystems management, and geographic information. These areas cross department and unit lines, linking them and unifying the research. We have also included in our financial statement information on the special grants we receive. These special grants allow us to provide research and outreach that is targeted toward economic development in Alaska. Research conducted by our graduate and undergraduate students plays an important role in these grants and the impact they make on Alaska.Financial statement -- Grants -- Students -- Research Reports: Partners, Facilities, and Programs; Geography; High-Latitude Agriculture; High-Latitude Soils; Management of Ecosystems; Natural Resources Use and Allocation; Index to Reports -- Publications -- Facult

Masting by Eighteen New Zealand Plant Species: The Role of Temperature as a Synchronizing Cue

Masting, the intermittent production of large flower or seed crops by a population of perennial plants, can enhance the reproductive success of participating plants and drive fluctuations in seed-consumer populations and other ecosystem components over large geographic areas. The spatial and taxonomic extent over which masting is synchronized can determine its success in enhancing individual plant fitness as well as its ecosystem-level effects, and it can indicate the types of proximal cues that enable reproductive synchrony. Here, we demonstrate high intra- and intergeneric synchrony in mast seeding by 17 species of New Zealand plants from four families across \u3e150000 km2. The synchronous species vary ecologically (pollination and dispersal modes) and are geographically widely separated, so intergeneric synchrony seems unlikely to be adaptive per se. Synchronous fruiting by these species was associated with anomalously high temperatures the summer before seedfall, a cue linked with the La Niña phase of El Niño–Southern Oscillation. The lone asynchronous species appears to respond to summer temperatures, but with a 2-yr rather than 1-yr time lag. The importance of temperature anomalies as cues for synchronized masting suggests that the timing and intensity of masting may be sensitive to global climate change, with widespread effects on taxonomically disparate plant and animal communities

Population Dynamics - Session 2

Multi-scale density-dependent dispersal in spatially structured populations Xavier Lambin, Chris Sutherland, David Elston Coupling agent-based with equation-based models to study spatially explicit megapopulation dynamics Patrick Giraudoux, Nicolas Marilleau, Christophe Lang The Bruce effect revisited: is pregnancy termination in female rodents an adaptation to ensure breeding success after male turnover in low densities? Jana A. Eccard, Melanie Dammhahn, Hannu Ylönen The long-haired rat (Rattus villosissimus): an ecosystem disrupter in arid Australia Chris R. Pavey, Catherine E. M. Nano The role of food availability in life history traits and population dynamics of the edible dormouse (Glis glis) in pine dominated forest Zbigniew Borowski, Kateryna Fyjałkowska, Anna Tereba, Aleksandra Tadeusiak Does anticipatory reproduction exist? Victoria A. Vekhnik, Vladimir P. Vekhnik Small mammals in montane forests: not where, but when? Ana Maria Benedek, Ioan Sîrbu Breeding versus survival: proximal causes of abrupt population decline under environmental change in a desert rodent Andrey Tchabovsky, Ludmila Savinetskaya, Elena Surkova Habitat preferences and spatial distribution of lemmings in western Taimyr Igor Yu. Popov The linkage between Melocanna bamboo flowering and rodent outbreaks: an empirical study from Chittagong Hill Tracts of Bangladesh Nikhil Chakma, Noor Jahan Sarker, Steven R. Belmain, Sohrab Uddin Sarker, Ken Aplin, Nazira Q. Kamal, Sontosh Kumar Sarker, AID-Comilla Population dynamics and breeding patterns of multimammate rat (Mastomys natalensi, Smith 1832) in semi-arid areas in Tanzania Emmanuel C.M. Mlyashimbi, Marien Joackim, Akwilini J. P. Tarimo, Didas N. Kimaro, Moses Isabirye, Robert S. Machang'u, Mashaka E. Mdangi, Rhodes H. Makundi, Herwig Leirs, Loth S. Mulungu Effects of stream proximity on trails of Cuniculus paca: a 20 year survey Jose M. Mora, Eduardo Carrillo It’s a trap: effective methods for monitoring mouse populations in Australia Peter R. Brown, Steve Henry, Roger P. Pech, Jennyffer Cruz, Lyn A. Hinds, Nikki Van de Weyer, Peter Caley Study on the evolutionary ecology of small herbivorous mammals: life history strategy of plateau pika (Ochotona curzoniae)Haiyan Nie, Jike LiuMulti-scale density-dependent dispersal in spatially structured populations Xavier Lambin, Chris Sutherland, David Elston Coupling agent-based with equation-based models to study spatially explicit megapopulation dynamics Patrick Giraudoux, Nicolas Marilleau, Christophe Lang The Bruce effect revisited: is pregnancy termination in female rodents an adaptation to ensure breeding success after male turnover in low densities? Jana A. Eccard, Melanie Dammhahn, Hannu Ylönen The long-haired rat (Rattus villosissimus): an ecosystem disrupter in arid Australia Chris R. Pavey, Catherine E. M. Nano The role of food availability in life history traits and population dynamics of the edible dormouse (Glis glis) in pine dominated forest Zbigniew Borowski, Kateryna Fyjałkowska, Anna Tereba, Aleksandra Tadeusiak Does anticipatory reproduction exist? Victoria A. Vekhnik, Vladimir P. Vekhnik Small mammals in montane forests: not where, but when? Ana Maria Benedek, Ioan Sîrbu Breeding versus survival: proximal causes of abrupt population decline under environmental change in a desert rodent Andrey Tchabovsky, Ludmila Savinetskaya, Elena Surkova Habitat preferences and spatial distribution of lemmings in western Taimyr Igor Yu. Popov The linkage between Melocanna bamboo flowering and rodent outbreaks: an empirical study from Chittagong Hill Tracts of Bangladesh Nikhil Chakma, Noor Jahan Sarker, Steven R. Belmain, Sohrab Uddin Sarker, Ken Aplin, Nazira Q. Kamal, Sontosh Kumar Sarker, AID-Comilla Population dynamics and breeding patterns of multimammate rat (Mastomys natalensi, Smith 1832) in semi-arid areas in Tanzania Emmanuel C.M. Mlyashimbi, Marien Joackim, Akwilini J. P. Tarimo, Didas N. Kimaro, Moses Isabirye, Robert S. Machang'u, Mashaka E. Mdangi, Rhodes H. Makundi, Herwig Leirs, Loth S. Mulungu Effects of stream proximity on trails of Cuniculus paca: a 20 year survey Jose M. Mora, Eduardo Carrillo It’s a trap: effective methods for monitoring mouse populations in Australia Peter R. Brown, Steve Henry, Roger P. Pech, Jennyffer Cruz, Lyn A. Hinds, Nikki Van de Weyer, Peter Caley Study on the evolutionary ecology of small herbivorous mammals: life history strategy of plateau pika (Ochotona curzoniae)Haiyan Nie, Jike Liu             Haiyan Nie, Jike Li

Annual Report: 2008

I submit herewith the annual report from the Agricultural and Forestry Experiment Station, School of Natural Resources and Agricultural Sciences, University of Alaska Fairbanks, for the period ending December 31, 2008. This is done in accordance with an act of Congress, approved March 2, 1887, entitled, “An act to establish agricultural experiment stations, in connection with the agricultural college established in the several states under the provisions of an act approved July 2, 1862, and under the acts supplementary thereto,” and also of the act of the Alaska Territorial Legislature, approved March 12, 1935, accepting the provisions of the act of Congress. The research reports are organized according to our strategic plan, which focuses on high-latitude soils, high-latitude agriculture, natural resources use and allocation, ecosystems management, and geographic information. These areas cross department and unit lines, linking them and unifying the research. We have also included in our financial statement information on the special grants we receive. These special grants allow us to provide research and outreach that is targeted toward economic development in Alaska. Research conducted by our graduate and undergraduate students plays an important role in these grants and the impact they make on Alaska.Financial statement -- Grants -- Students -- Research reports: Partners, Facilities, and Programs; Geographic Information; High-Latitude Agriculture; High-Latitude Soils, Management of Ecosystems; Natural Resources Use and Allocation; Index to Reports -- Publications -- Facult

Interspecific interactions between Penstemon palmeri and shrubs in the arid shrublands of the Spring Mountains, Nevada

A project involving shrub removal was undertaken by the United States Forest Service in the Spring Mountains National Recreation Area (SMNRA) to reduce accumulated woody fuels, which can pose risks to human communities. This research focuses on the interactions between shrubs and the perennial forb Palmer\u27s penstemon (Penstemon palmeri), one of many nectar sources for the endemic Spring Mountains Acastus Checkerspot Butterfly (Chlosyne acastus ssp robusta). Initial observations revealed that P. palmeri (`penstemon\u27) seemed to grow almost exclusively under shrubs. Such spatial associations are often indicative of a history of positive interactions between plants, and led to the research presented here. These studies investigate and discuss the interactions between this penstemon and shrubs in the arid shrublands of the SMNRA. Spatial patterns between populations of penstemon and shrubs were measured during November 2008-May 2011, and the consequences of shrub-association for individual penstemon emergence, survival, growth, and reproduction were documented (Chapter 2). The results suggest that although shrubs reduced penstemon emergence, they increased seedling survival (a seed-seedling conflict) resulting in a strong shift toward association between shrubs and penstemon over time. Further, while no differences in growth were detected between microhabitats, the results suggest that shrubs inhibited P. palmeri flowering but improved the successful maturation of fruits when flowering occurred. The mechanisms driving these patterns were elusive, but seed-sowing and seedling transplant experiments suggested that shrub soils, rather than their canopies, alter the nature of seed-seedling conflicts in a way that may promote seed-bank persistence in penstemon populations (Chapter 3). To provide a detailed description of the reproductive response of penstemon to shrubs, structural equation modeling was used to describe the importance of shrubs for penstemon seed production (Chapter 4). The results suggest that competition with shrubs reduced penstemon seed production, but that shrubs simultaneously facilitated penstemon water balance and altered the foraging behavior of its pollinators, indirectly increasing seed production. I conclude by discussing the importance of these studies, and studies of plant interactions in general, for helping land managers balance the objectives of fuel load reduction with protecting desirable species (Chapter 5)