Repellent response of female agromyzid flies to leafminer-infested bean plants

USDA-ARS?s Scientific Manuscript database

Liriomyza sativae Blanchard, L. trifolii (Burgess) and L. huidobrensis (Blanchard) are three invasive leafminer species (Diptera: Agromyzidae) in China that have caused significant economic damage on vegetables and ornamental plants. In the current study, the repellent responses of female adults to ...

Insecticide-mediated apparent displacement between two invasive species of Leafminer fly

USDA-ARS?s Scientific Manuscript database

Closely related invasive species may often displace one another, but it is often difficult to determine mechanisms because of the historical nature of these events. The leafmining flies Liriomyza sativae and Liriomyza trifolii have become serious invasive agricultural pests throughout the world. W...

Genetic diversity and association analysis of leafminer (Liriomyza langei) resistance in spinach (Spinacia oleracea)

USDA-ARS?s Scientific Manuscript database

Leafminer (Liriomyza spp.) is a major insect pest of many important agricultural crops, including spinach (Spinacia oleracea). Use of genetic resistance is an efficient, economic and environment-friendly method to control this pest. The objective of this research was to conduct association analysis ...

Species displacements are common to two invasive species of leafminer fly in China, Japan and the United States

USDA-ARS?s Scientific Manuscript database

Under field conditions, species displacements have occurred in different directions between the same invasive species of leafminers (Diptera: Agromyzidae). Liriomyza sativae (Blanchard) was displaced by L. trifolii (Burgess) in the western USA, with evidence suggesting that lower insecticide suscept...

Injection of emamectin benzoate protects paper birch from birch leafminer (Hymenoptera: Tenthredinidae) for two field seasons

Treesearch

Christopher J. Fettig; Roger E. Burnside; Mark E. Schultz

2013-01-01

Ambermarked birch leafminer, Profenusa thomsoni (Konow) (Hymenoptera: Tenthredinidae), is an exotic, invasive pest of urban and wildland birch. We initiated a study near Fairbanks, Alaska to determine the efficacy of emamectin benzoate (TREE-äge®, Arborjet Inc., Woburn, MA) for control of P. thomsoni on paper...

Illustrated review of the leaf-mining Nepticulidae of the central Andes (Peru and Bolivia).

PubMed

Stonis, Jonas R; Diškus, Arūnas; Remeikis, Andrius; Karsholt, Ole; Torres, Nixon Cumbicus

2017-04-24

We review forty-five species of Nepticulidae (Lepidoptera) based on an analysis of samples collected in the central Andean region of Peru and Bolivia. Thirteen of these species are new to science, and are named and described here: Stigmella paracosma Remeikis & Stonis, sp. nov., S. expressa Remeikis & Stonis, sp. nov., S. acalyphae Diškus & Stonis, sp. nov., S. lepida Diškus & Stonis, sp. nov., S. misera Diškus & Stonis, sp. nov., S. inca Diškus & Stonis, sp. nov., S. eiffeli Diškus & Stonis, sp. nov., S. arequipica Remeikis & Stonis, sp. nov., S. coronaria Diškus & Stonis, sp. nov., S. azulella Diškus & Stonis, sp. nov., S. sparsella Diškus & Stonis, sp. nov., Manoneura forcipis Diškus & Stonis, sp. nov., and Acalyptris murex Diškus & Stonis, sp. nov. Some of the central Andean species are recorded here as leaf-miners on Euphorbiaceae (Acalypha), Fabaceae (Collaea), Rosaceae (Polylepis), Malvaceae (Sida), Calceolariaceae (Calceolaria), Lamiaceae (Clinopodium), and Asteraceae (Ageratina and Trixis). We create eleven new species groups based on morphological characters designated in Stigmella and one in Acalyptris. A pictorial key to the species groups and distribution maps are provided. All new species are illustrated with 150 photographs and drawings of the adults and genitalia, and, where known and/or available, photographs of host-plants and leaf-mines.

MU06-857, a Green Leaf Lettuce Breeding Line with Resistance to Leafminer and Lettuce Mosaic Virus.

USDA-ARS?s Scientific Manuscript database

The Agricultural Research Service, United States Department of Agriculture announces the release of a breeding line of green leaf lettuce (Lactuca sativa L.) with resistance to leafminers (Liriomyza langei Frick) and lettuce mosaic. The line MU06-857 is similar to cultivar ‘Lolla Rossa’ (‘Lollo Ros...

Seasonal abundance of eggplant leafminer Liriomyza sativae (Blanchard, 1938) (Diptera, Agromyzidae) in plastic-house

NASA Astrophysics Data System (ADS)

Kathiar, S. A.; Flaih, S. K.; Al-Khazraji, H. I.; Ismael, S. K.

2018-05-01

The eggplant Solanum melongena L. crop is attacked by one of the most common pests which is the leafminer Liriomyza sativae (Blanchard, 1938); therefore, this investigation was conducted to study the seasonal abundance of the eggplant leafminer in eggplant Plastic-house. The results showed that the highest average of infested leaves was 6.67 leaf, the highest average of tunnels by leaf miner was 9.87 tunnels and the highest percent of infestation was recorded 30.5% in 23. April. 2017. This study showed the parasitoid Diglyphus isaea (Walker, 1838) (Hymenoptera, Eulophidae) was recorded as a natural enemy to control the pest and the highest incidence of parasitism was 32.2 parasites on average in 16. April. 2017.

Disruption of the leafminer Phyllocnistis citrella (Lepidoptera: Gracillariidae) in citrus: effect of blend and placement height, longevity of disruption and emission profile of a new dispenser

USDA-ARS?s Scientific Manuscript database

Recent efforts to disrupt mating of the leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), a global pest of citrus, have focused on the use of SPLAT™ (ISCA Technologies), a flowable wax emulsion intended to serve as a slow-release matrix for pheromones. Early success with this...

Pre-release efficacy assessment of the leaf-mining moth Digitivalva delaireae (Lepidoptera: Glyphipterigidae), a potential biological control agent for Cape-ivy, Delairea odorata (Asteraceae), in western North America

USDA-ARS?s Scientific Manuscript database

The leaf-mining moth Digitivalva delaireae Gaedike & Kruger (Lepidoptera: Glyphipterigidae) is a potential biological control agent for the invasive vine Cape-ivy, Delairea odorata Lemaire (Asteraceae), in western North America, where two morphological varieties (stipulate and exstipulate) of Cape-i...

Aesculus pavia foliar saponins: defensive role against the leafminer Cameraria ohridella.

PubMed

Ferracini, Chiara; Curir, Paolo; Dolci, Marcello; Lanzotti, Virginia; Alma, Alberto

2010-07-01

Recently, the leafminer Cameraria ohridella Deschka & Dimic has caused heavy damage to the white-flowering horse chestnut in Europe. Among the Aesculus genus, A. pavia L. HBT genotype, characterised by red flowers, showed an atypical resistance towards this pest. Its leaves, shaken in water, originated a dense foam, indicating the presence of saponins, unlike the common horse chestnut tree. The aim was to isolate and identify these leaf saponins and test their possible defensive role against C. ohridella. Spectroscopic analyses showed that A. pavia HBT genotype leaves contained a mixture of saponins, four of which were based on the same structure as commercial escin saponins, the typical saponin mixture produced by A. hippocastanum and accumulated only within bark and fruit tissues. The mixture showed a repellent effect on C. ohridella moth. The number of mines detected on the leaves of A. hippocastanum plants treated with A. pavia HBT saponins through watering and stem brushing was significantly lower than the control, and in many cases no mines were ever observed. The results showed that the exogenous saponins were translocated from roots/stem to the leaf tissues, and their accumulation seemed to ensure an appreciable degree of protection against the leafminer. Copyright (c) 2010 Society of Chemical Industry.

First discovery of Quercus-feeding Nepticulidae (Lepidoptera) in South America, with description of new species and designation of the S. nigriverticella complex in the S. saginella group.

PubMed

Remeikis, Andrius; Stonis, Jonas R

2015-12-11

We describe three new species: Stigmella crassifoliae Remeikis & Stonis, sp. nov. (a leaf-miner on Quercus crassifolia and Q. crispipilis from the highlands of Guatemala), S. robleae Remeikis & Stonis, sp. nov., and S. humboldti Remeikis & Stonis, sp. nov. (leaf-miners on Quercus humboldtii from the Colombian Andes). No Quercus-feeding Nepticulidae species were previously known from South America. All new species are illustrated with photographs of the leaf-mines, cocoons, adults, and genitalia. In the S. saginella species group, for the species possessing in male genitalia M-shaped gnathos with caudal processes closely juxtaposed and phallus without cornuti, a new species complex (the S. nigriverticella complex) is defined. We also provide a pictorial key to the species of the new complex.

A survey of Agromyzidae (Diptera) reared from leafmines on Long Island, New York; new host associations, distribution data, and the description of a new species

USDA-ARS?s Scientific Manuscript database

Leafmining Agromyzidae (Diptera) are both common and widespread, yet little is known of the host associations and distribution of most species. Here we report on a multi-year study of agromyzid diversity on Long Island, New York. We reared 48 species and found six new host records. Of the 48 species...

Impact of natural control agents of the citrus leafminer Phyllocnistis citrella on lemon trees varies among seasons.

PubMed

Goane, L; Casmuz, A; Salas, H; Willink, E; Mangeaud, A; Valladares, G

2015-12-01

Studies on insect natural enemies and their effects on host populations are of immense practical value in pest management. Predation and parasitism on a citrus pest, the leafminer Phyllocnistis citrella Stainton, were evaluated by sampling over 3 years in four locations within a world leading lemon producing area in Northwest Argentina. Both mortality factors showed seasonal trends consistent across locations, with predation exerting earlier and more sustained pressure than parasitism, which showed wider seasonal variations. The dominant parasitoids, native Cirrospilus neotropicus and introduced Ageniaspis citricola, showed different seasonal trends: C. neotropicus was dominant in spring whereas A. citricola superseded it in autumn and winter. Although parasitism rates were relatively low, the native C. neotropicus revealed favourable features as potential control agent, by showing density-dependence, parasitism rates comparable with those of the specific A. citricola during part of the cycle, and earlier synchronization with the host. The study provides highly relevant information for a sustainable management of this worldwide pest, for which biological control is considered the best long-term option.

Antispila oinophylla new species (Lepidoptera, Heliozelidae), a new North American grapevine leafminer invading Italian vineyards: taxonomy, DNA barcodes and life cycle

PubMed Central

van Nieukerken, Erik J.; Wagner, David L.; Baldessari, Mario; Mazzon, Luca; Angeli, Gino; Girolami, Vicenzo; Duso, Carlo; Doorenweerd, Camiel

2012-01-01

Abstract A grapevine leafminer Antispila oinophylla van Nieukerken & Wagner, sp. n., is described both from eastern North America (type locality: Georgia) and as a new important invader in North Italian vineyards (Trentino and Veneto Region) since 2006. The species is closely related to, and previously confused with Antispila ampelopsifoliella Chambers, 1874, a species feeding on Virginia creeper Parthenocissus quinquefolia (L.) Planchon., and both are placed in an informal Antispila ampelopsifoliella group. Wing pattern, genitalia, and DNA barcode data all confirm the conspecificity of native North American populations and Italian populations. COI barcodes differ by only 0–1.23%, indicating that the Italian populations are recently established from eastern North America. The new species feeds on various wild Vitis species in North America, on cultivated Vitis vinifera L. in Italy, and also on Parthenocissus quinquefolia in Italy. North American Antispila feeding on Parthenocissus include at least two other species, one of which is Antispila ampelopsifoliella. Morphology and biology of the new species are contrasted with those of North American Antispila Hübner, 1825 species and European Holocacista rivillei (Stainton, 1855). The source population of the introduction is unknown, but cases with larvae or pupae, attached to imported plants, are a likely possibility. DNA barcodes of the three European grapevine leafminers and those of all examined Heliozelidae are highly diagnostic. North American Vitaceae-feeding Antispila form two species complexes and include several as yet unnamed taxa. The identity of three out of the four previously described North American Vitaceae-feeding species cannot be unequivocally determined without further revision, but these are held to be different from Antispila oinophylla. In Italy the biology of Antispila oinophylla was studied in a vineyard in the Trento Province (Trentino-Alto Adige Region) in 2008 and 2009. Mature larvae overwinter inside their cases, fixed to vine trunks or training stakes. The first generation flies in June. An additional generation occurs from mid-August onwards. The impact of the pest in this vineyard was significant with more than 90% of leaves infested in mid-summer. Since the initial discovery in 2006, the pest spread to several additional Italian provinces, in 2010 the incidence of infestation was locally high in commercial vineyards. Preliminary phylogenetic analyses suggest that Antispila is paraphyletic, and that the Antispila ampelopsifoliella group is related to Coptodisca Walsingham, 1895, Holocacista Walsingham & Durrant, 1909 and Antispilina Hering, 1941, all of which possess reduced wing venation. Vitaceae may be the ancestral hostplant family for modern Heliozelidae. PMID:22408380

Developing and implementing mating disruption for area-wide control of citrus leafminer and citrus canker disease

USDA-ARS?s Scientific Manuscript database

Successful development and commercial launch of the first semiochemical-based control method for a major exotic insect pest and associated disease of citrus in Florida have resulted from vigorous collaboration between university and government researchers with support from private industry and innov...

Leaf-mining by Phyllonorycter blancardella reprograms the host-leaf transcriptome to modulate phytohormones associated with nutrient mobilization and plant defense.

PubMed

Zhang, Hui; Dugé de Bernonville, Thomas; Body, Mélanie; Glevarec, Gaëlle; Reichelt, Michael; Unsicker, Sybille; Bruneau, Maryline; Renou, Jean-Pierre; Huguet, Elisabeth; Dubreuil, Géraldine; Giron, David

2016-01-01

Phytohormones have long been hypothesized to play a key role in the interactions between plant-manipulating organisms and their host-plants such as insect-plant interactions that lead to gall or 'green-islands' induction. However, mechanistic understanding of how phytohormones operate in these plant reconfigurations is lacking due to limited information on the molecular and biochemical phytohormonal modulation following attack by plant-manipulating insects. In an attempt to fill this gap, the present study provides an extensive characterization of how the leaf-miner Phyllonorycter blancardella modulates the major phytohormones and the transcriptional activity of plant cells in leaves of Malus domestica. We show here, that cytokinins strongly accumulate in mined tissues despite a weak expression of plant cytokinin-related genes. Leaf-mining is also associated with enhanced biosynthesis of jasmonic acid precursors but not the active form, a weak alteration of the salicylic acid pathway and a clear inhibition of the abscisic acid pathway. Our study consolidates previous results suggesting that insects may produce and deliver cytokinins to the plant as a strategy to manipulate the physiology of the leaf to create a favorable nutritional environment. We also demonstrate that leaf-mining by P. blancardella leads to a strong reprogramming of the plant phytohormonal balance associated with increased nutrient mobilization, inhibition of leaf senescence and mitigation of plant direct and indirect defense. Copyright © 2015 Elsevier Ltd. All rights reserved.

Decreased losses of woody plant foliage to insects in large urban areas are explained by bird predation.

PubMed

Kozlov, Mikhail V; Lanta, Vojtěch; Zverev, Vitali; Rainio, Kalle; Kunavin, Mikhail A; Zvereva, Elena L

2017-10-01

Despite the increasing rate of urbanization, the consequences of this process on biotic interactions remain insufficiently studied. Our aims were to identify the general pattern of urbanization impact on background insect herbivory, to explore variations in this impact related to characteristics of both urban areas and insect-plant systems, and to uncover the factors governing urbanization impacts on insect herbivory. We compared the foliar damage inflicted on the most common trees by defoliating, leafmining and gall-forming insects in rural and urban habitats associated with 16 European cities. In two of these cities, we explored quality of birch foliage for herbivorous insects, mortality of leafmining insects due to predators and parasitoids and bird predation on artificial plasticine larvae. On average, the foliage losses to insects were 16.5% lower in urban than in rural habitats. The magnitude of the overall adverse effect of urbanization on herbivory was independent of the latitude of the locality and was similar in all 11 studied tree species, but increased with an increase in the size of the urban area: it was significant in large cities (city population 1-5 million) but not significant in medium-sized and small towns. Quality of birch foliage for herbivorous insects was slightly higher in urban habitats than in rural habitats. At the same time, leafminer mortality due to ants and birds and the bird attack intensity on dummy larvae were higher in large cities than in rural habitats, which at least partially explained the decline in insect herbivory observed in response to urbanization. Our findings underscore the importance of top-down forces in mediating impacts of urbanization on plant-feeding insects: factors favouring predators may override the positive effects of temperature elevation on insects and thus reduce plant damage. © 2017 John Wiley & Sons Ltd.

Insect-induced effects on plants and possible effectors used by galling and leaf-mining insects to manipulate their host-plant.

PubMed

Giron, David; Huguet, Elisabeth; Stone, Graham N; Body, Mélanie

2016-01-01

Gall-inducing insects are iconic examples in the manipulation and reprogramming of plant development, inducing spectacular morphological and physiological changes of host-plant tissues within which the insect feeds and grows. Despite decades of research, effectors involved in gall induction and basic mechanisms of gall formation remain unknown. Recent research suggests that some aspects of the plant manipulation shown by gall-inducers may be shared with other insect herbivorous life histories. Here, we illustrate similarities and contrasts by reviewing current knowledge of metabolic and morphological effects induced on plants by gall-inducing and leaf-mining insects, and ask whether leaf-miners can also be considered to be plant reprogrammers. We review key plant functions targeted by various plant reprogrammers, including plant-manipulating insects and nematodes, and functionally characterize insect herbivore-derived effectors to provide a broader understanding of possible mechanisms used in host-plant manipulation. Consequences of plant reprogramming in terms of ecology, coevolution and diversification of plant-manipulating insects are also discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Host tracking or cryptic adaptation? Phylogeography of Pediobius saulius (Hymenoptera, Eulophidae), a parasitoid of the highly invasive horse-chestnut leafminer

PubMed Central

Hernández-López, Antonio; Rougerie, Rodolphe; Augustin, Sylvie; Lees, David C; Tomov, Rumen; Kenis, Marc; Çota, Ejup; Kullaj, Endrit; Hansson, Christer; Grabenweger, Giselher; Roques, Alain; López-Vaamonde, Carlos

2012-01-01

Classical biological control is often advocated as a tool for managing invasive species. However, accurate evaluations of parasitoid species complexes and assessment of host specificity are impeded by the lack of morphological variation. Here, we study the possibility of host races/species within the eulophid wasp Pediobius saulius, a pupal generalist parasitoid that parasitize the highly invasive horse-chestnut leaf-mining moth Cameraria ohridella. We analysed the population genetic structure, host associations and phylogeographic patterns of P. saulius in Europe using the COI mitochondrial gene. This marker strongly supports a division into at least five highly differentiated parasitoid complexes, within two of which clades with differing degrees of host specialization were found: a Balkan clade that mainly (but not only) attacks C. ohridella and a more generalist European group that attacks many hosts, including C. ohridella. The divergence in COI (up to 7.6%) suggests the existence of cryptic species, although this is neither confirmed by nuclear divergence nor morphology. We do not find evidence of host tracking. The higher parasitism rates observed in the Balkans and the scarcity of the Balkan–Cameraria haplotypes out of the Balkans open the possibility of using these Balkan haplotypes as biological control agents of C. ohridella elsewhere in Europe. PMID:25568046

What Limits the Distribution of Liriomyza huidobrensis and Its Congener Liriomyza sativae in Their Native Niche: When Temperature and Competition Affect Species' Distribution Range in Guatemala.

PubMed

Rodríguez-Castañeda, G; MacVean, C; Cardona, C; Hof, A R

2017-07-01

Factors limiting distribution range for most species are generally unknown regardless of whether they are native or invasive. We studied factors that could enable or restrict the distribution of two cosmopolitan invasive leafminer fly species, Liriomyza huidobrensis (Blanchard) and Liriomyza sativae (Blanchard) in their native niche. In order to test which ecological and environmental factors affect leafminer distribution we conducted thermal tolerance assays, sampled along elevation gradients and modeled species distribution. Findings from the field and rearing chambers showed a physiological restriction due to high temperatures for L. huidobrensis at 28-29 °C, above which adult emergence is compromised. We also found that maximum temperatures below 22 °C, typical of tropical highlands, favored L. huidobrensis. L. sativae was found across a wider temperature range (i.e., from 21 to 36 °C) in Guatemala. Our finding of a physiological threshold in temperature for L. huidobrensis may enable us to predict its invasive risk when combined with the environmental conditions at horticultural ports of entry and the global agricultural landscape. Further, it strengthens our predictions on shifts in distribution of the leafminer fly under future climate. We also found a temperature mediated competitive exclusion interaction between the two herbivore species, where L. sativae occurred at temperatures < 22 °C only in the absence of L. huidobrensis. We show that parasitoids had a negative effect on the leafminer flies, which varied with host plant. Finally, we show the importance of taking a multiaspect approach when investigating what limits distribution and invasiveness of a species. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Selection for chlorpyrifos resistance in Liriomyza sativae Blanchard: Cross-resistance patterns, stability and biochemical mechanisms.

PubMed

Askari-Saryazdi, Ghasem; Hejazi, Mir Jalil; Ferguson, J Scott; Rashidi, Mohammad-Reza

2015-10-01

The vegetable leafminer (VLM), Liriomyza sativae (Diptera: Agromyzidae) is a serious pest of vegetable crops and ornamentals worldwide. In cropping systems with inappropriate management strategies, development of resistance to insecticides in leafminers is probable. Chlorpyrifos is a commonly used pesticide for controlling leafminers in Iran, but resistance to this insecticide in leafminers has not been characterized. In order to develop strategies to minimize resistance in the field and greenhouse, a laboratory selected chlorpyrifos resistant strain of L. sativae was used to characterize resistance and determine the rate of development and stability of resistance. Selecting for resistance in the laboratory after 23 generations yielded a chlorpyrifos resistant selected strain (CRSS) with a resistance ratio of 40.34, determined on the larval stage. CRSS exhibited no cross-resistance to other tested insecticides except for diazinon. Synergism and biochemical assays indicated that esterases (EST) had a key role in metabolic resistance to chlorpyrifos, but glutathione S-transferase (GST) and mixed function oxidase (MFO) were not mediators in this resistance. In CRSS acetylcholinesterase (AChE) was more active than the susceptible strain, Sharif (SH). AChE in CRSS was also less sensitive to inhibition by propoxur. The kinetics parameters (Km and Vmax) of AChE indicated that affinities and hydrolyzing efficiencies of this enzyme in CRSS were higher than SH. Susceptibility to chlorpyrifos in L. sativae was re-gained in the absence of insecticide pressure. Synergism, biochemical and cross-resistance assays revealed that overactivity of metabolic enzymes and reduction in target site sensitivity are probably joint factors in chlorpyrifos resistance. An effective insecticide resistance management program is necessary to prevent fast resistance development in crop systems. Copyright © 2015 Elsevier Inc. All rights reserved.

New species of leaf-mining Nepticulidae (Lepidoptera) from the Neotropical and Ando-Patagonian regions, with new data on host plants.

PubMed

Stonis, Jonas R; Remeikis, Andrius; Diškus, Arūnas; Megoran, Nick

2017-05-26

The paper treats fifteen species of leaf-mining pygmy moths (Insecta, Lepidoptera, Nepticulidae) discovered in the Neotropics (British Virgin Islands, Belize, Costa Rica, Venezuela, and Ecuador), and Ando-Patagonian region (Argentina and Chile). Except for two species, all belong to Stigmella Schrank. Twelve species are new, and are named and described in the current paper: Stigmella apicibrunella Diškus & Stonis, sp. nov.; S. decora Diškus & Stonis, sp. nov.; S. unicaudata Remeikis & Stonis, sp. nov.; S. sanmartini Remeikis & Stonis, sp. nov.; S. patula Remeikis & Stonis, sp. nov.; S. torosa Remeikis & Stonis, sp. nov.; S. monstrata Remeikis & Stonis, sp. nov.; S. huahumi Remeikis & Stonis, sp. nov.; S. venezuelica Remeikis & Stonis, sp. nov.; S. virginica Remeikis & Stonis, sp. nov.; Fomoria miranda Diškus & Stonis, sp. nov.; and Hesperolyra robinsoni Stonis, sp. n. Newly discovered variation of male genitalia of the Andean Stigmella rudis Puplesis & Robinson, 2000 is briefly discussed, and the formerly poorly understood Stigmella hylomaga (Meyrick, 1931) is redescribed and documented with photographs for the first time. We also present more photographs and add some addtional information on Stigmella gallicola van Nieukerken & Nishida, a recently described gall-maker from Costa Rica.The paper also provides new host-plant data: some of the described (or redescribed) species are reported for the first time as leaf-miners on plants belonging to Euphorbiaceae (Acalypha padifolia Kunth), Salicaceae (Azara microphylla Hook. f.), Fabaceae (Inga spectabilis (Vahl) Willd. or I. edulis Mart.), Rhamnaceae (Colletia spinosissima J. F. Gmel.), Geraniaceae or Vivianiaceae (Rhynchotheca spinosa Ruiz & Pav.), and Asteraceae (Mutisia decurrens Cav.). All species treated in the paper are illustrated with photographs of the adults and genitalia, a distribution map, and also photographs of the leaf-mines and host plants when available.

Control of the Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), in Open-Field Tomatoes by Indigenous Natural Enemies Occurring in Israel.

PubMed

Shaltiel-Harpaz, Liora; Gerling, Dan; Graph, Shaul; Kedoshim, Hendrika; Azolay, Lotem; Rozenberg, Tamir; Nachache, Yaakov; Steinberg, Shimon; Allouche, Arnon; Alon, Tamar

2016-02-01

The tomato leafminer, Tuta absoluta (Meyrick), had established in Israel by 2010, attacking both open-field tomatoes and greenhouse crops.We searched for its natural enemies in open-field tomatoes, and tried to determine their potential for controlling this pest. We surveyed the local natural enemies in open tomato fields and measured their impact on pest populations in an unsprayed field. We assessed the suppressive ability of the dominant hemipteran predator, Nesidiocoris tenuis Reuter, against T. absoluta under controlled laboratory conditions and evaluated the impact of its augmentation on T. absoluta control in open-field tomatoes. We found five natural enemy species:the predator, N. tenuis, two braconids, and two eulophids. Predation accounted for 64.5±9.2% (mean ± SE) of T. absoluta larval mortality, whereas parasitism accounted for 20.96±7.5%. Together, they eliminated the pest population at tomato harvest time. Under controlled conditions, predation by N. tenuis rose from 58 to 72% with increased density of T. absoluta, suggesting positive density dependence. The reduction of T. absoluta (83%) by N. tenuis was higher than that of Bemisia tabaci (32%), suggesting a preference of N. tenuis for T. absoluta. Augmentation of N.tenuis was as effective as conventional treatment insecticide treatment, and plant damage was low and did not seem to affect yield. Results indicate that reduced pesticide use enables indigenous natural enemies, particularly N.tenuis, to successfully control T. absoluta and prevent crop damage in open-field tomatoes.

First description of leaf-mining Nepticulidae and Tischeriidae (Insecta, Lepidoptera) feeding on the Chilean endemic plant genus Podanthus Lag. (Asteraceae).

PubMed

Stonis, Jonas R; Diškus, Arūnas; Remeikis, Andrius; Torres, Nixon Cumbicus

2016-01-05

Despite taxonomic and conservation interest in the Chilean endemic plant genus Podanthus Lag. (Asteraceae: subfamily Asteroideae, tribe Heliantheae), no Podanthus-feeding Nepticulidae or Tischeriidae have ever been recorded. Here, on the basis of material reared from Podanthus from central Mediterranean Chile, we present the description of Stigmella podanthae sp. nov. (Nepticulidae) and a re-description of Astrotischeria chilei Puplesis & Diškus, 2003. Females and host-plant of the latter species were previously unknown. Both treated species are illustrated with numerous photographs of the leaf-mines, adults of both sexes, and male and female genitalia.

Ecological trade-offs between jasmonic acid-dependent direct and indirect plant defences in tritrophic interactions

PubMed Central

Wei, Jianing; Wang, Lizhong; Zhao, Jiuhai; Li, Chuanyou; Ge, Feng; Kang, Le

2011-01-01

Recent studies on plants genetically modified in jasmonic acid (JA) signalling support the hypothesis that the jasmonate family of oxylipins plays an important role in mediating direct and indirect plant defences. However, the interaction of two modes of defence in tritrophic systems is largely unknown. In this study, we examined the preference and performance of a herbivorous leafminer (Liriomyza huidobrensis) and its parasitic wasp (Opius dissitus) on three tomato genotypes: a wild-type (WT) plant, a JA biosynthesis (spr2) mutant, and a JA-overexpression 35S::prosys plant. Their proteinase inhibitor production and volatile emission were used as direct and indirect defence factors to evaluate the responses of leafminers and parasitoids. Here, we show that although spr2 mutant plants are compromised in direct defence against the larval leafminers and in attracting parasitoids, they are less attractive to adult flies compared with WT plants. Moreover, in comparison to other genotypes, the 35S::prosys plant displays greater direct and constitutive indirect defences, but reduced success of parasitism by parasitoids. Taken together, these results suggest that there are distinguished ecological trade-offs between JA-dependent direct and indirect defences in genetically modified plants whose fitness should be assessed in tritrophic systems and under natural conditions. PMID:21039561

A new leafminer on grapevine and Rhoicissus (Vitaceae) in South Africa within an expanded generic concept of Holocacista (Insecta, Lepidoptera, Heliozelidae)

PubMed Central

van Nieukerken, Erik J.; Geertsema, Henk

2015-01-01

Abstract A grapevine leafminer found recently in table grape orchards and vineyards in the Paarl region (Western Cape, South Africa) is described as Holocacista capensis sp. n. It has also been found on native Rhoicissus digitata and bred on that species in the laboratory. It is closely related to Holocacista salutans (Meyrick, 1921), comb. n. (from Antispila), described from Durban in KwaZulu-Natal, but widespread in southern Africa and a native leafminer of various Vitaceae: Rhoicissus tomentosa, Rhoicissus digitata, Rhoicissus tridentata and Cissus cornifolia. Holocacista capensis has been found on Vitis vinifera both in Gauteng and Western Cape, the earliest record being from 1950 in Pretoria. The initial host shift from native Vitaceae to Vitis must have occurred much earlier. The species is sometimes present in high densities, but hitherto no sizeable damage to the crops has been noted. The genus Holocacista Walsingham & Durrant, 1909, previously known from the single European grapevine leafminer Holocacista rivillei (Stainton, 1855), is expanded and redescribed and for the first time reported from Africa, East and South-East Asia and Australia. It comprises seven named species and at least 15 unnamed species. The following species are also recombined with Holocacista: transferred from Antispilina: South-African Holocacista varii (Mey, 2011), comb. n., feeding on Pelargonium, transferred from Antispila: the Indian species Holocacista micrarcha (Meyrick, 1926), comb. n. and Holocacista pariodelta (Meyrick, 1929), comb. n., both feeding on Lannea coromandelica, and Holocacista selastis (Meyrick, 1926), comb. n. on Psychotria dalzelii. We also remove the following from Antispila: Heliozela anna (Fletcher, 1920), comb. n. and Heliozela argyrozona (Meyrick, 1918), comb. n., whereas the following Indian Vitaceae feeding species are confirmed to belong in Antispila s. str.: Antispila argostoma Meyrick, 1916 and Antispila aristarcha Meyrick, 1916. Holocacista salutans and Holocacista varii are redescribed and diagnosed against Holocacista capensis and other South African Heliozelidae. DNA barcodes are provided for 13 species of Holocacista. PMID:26155071

[Parasitism in Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) in Citrus orchards in Montenegro, RS, Brazil].

PubMed

Jahnke, Simone M; Redaelli, Luiza R; Diefenbach, Lúcia M G

2006-01-01

Phyllocnistis citrella Stainton, the citrus-leafminer, is an important pest of citrus worldwide. Knowledge of natural parasitism levels is fundamental to the establishment of tactics of management and control of this species. This work aimed to evaluate the parasitism in two citrus orchards, one of 'Montenegrina' (Citrus deliciosa Ten.) and the other of 'Murcott' (C. sinensis (L.) Osbeck x C. reticulata Blanco), located in Montenegro, RS. In fortnightly samplings, from July/2001 to June/2003, all leaves containing P. citrella pupae from randomly selected plants were collected and maintained individually until emergence of the parasitoids or the citrus-leafminer. Parasitism was calculated considering the number of emerged parasitoids relative to the total number of emerged individuals. Correlation and linear regression tests were done to evaluate the relationship and the influence of biotic and abiotic factors upon the parasitism index. In both orchards the greatest parasitism percentage was registered on autumn in both years. The total percentage was 36.2% in 'Murcott' and 26.4% in 'Montenegrina' in the first year, and 30.2% and 37.6%, respectively, in the second year. In 'Murcott', this index did not differed between the years (chi2 = 2.06; df = 1; P > 0.05), in 'Montenegrina' the parasitism was significantly higher in the second year (chi2 = 7.36; df = 1; P < 0.05). The correlation and linear regression tests indicated a strong influence, in the parasitism index, of the host populational density registered in the previous 45 and 135 days.

Differential Effects of Pesticide Applications on Liriomyza huidobrensis (Diptera: Agromyzidae) and its Parasitoids on Pea in Central Kenya.

PubMed

Guantai, M M; Ogol, C P K O; Salifu, D; Kasina, J M; Akutse, K S; Fiaboe, K K M

2015-04-01

Three Liriomyza species [Liriomyza huidobrensis (Blanchard), Liriomyza trifolii (Burgess), and Liriomyza sativae Blanchard] have been reported as the most important leafminer pests in vegetable production systems in Africa. In Kenya, farmers rely on indiscriminate synthetic insecticides use. On-farm field investigations were set up at three different locations (Sagana, Kabaru, and Naromoru) in central Kenya to determine the effect of pesticide application on the abundance of leafminers and their parasitoids under three management practices, namely: farmer practice (FP), reduced pesticide use (RP), and a control with no use of pesticides (CO). In addition, laboratory experiments were designed to test the effect of commonly used pesticides in pea production systems in central Kenya--Dimethoate, Dynamec, Thunder, Cyclone, Bestox, Folicur, Milraz, and Bulldock--on L. huidobrensis and two of its parasitoids, Diglyphus isaea Walker and Phaedrotoma scabriventris Nixon. The mean numbers of leafminer flies in control treatment were higher than in RP and FP in both first and second seasons across all sites, but RP and FP did not differ significantly. Parasitoid numbers were very low and there was no much variation between treatments at each location in both first and second seasons. No significant differences were observed between the three management practices with regards to the yield measurements. In the laboratory, the estimated LD50 values for L. huidobrensis larvae were all more than two times higher than the recommended dosages, while the LD50 of adults were below the recommended dosages. The estimated LD50 values for the parasitoids were much lower than recommended dosages for all pesticides except Thunder. This study, therefore, demonstrates that the pesticides currently used do not control the Liriomyza leafminer larvae that constitute the most destructive stage of the pest, but are rather detrimental to their parasitoids. In addition, the current low level of parasitoids recorded under field conditions even where no pesticide was used during this study, warrants consideration of classical biological control programs. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Leaf-mining Nepticulidae (Lepidoptera) from record high altitudes: documenting an entire new fauna in the Andean páramo and puna.

PubMed

Stonis, Jonas R; Diškus, Arūnas; Remeikis, Andrius; Gerulaitis, Virginijus; Karsholt, Ole

2016-11-01

The monograph treats 29 species of leaf-mining pygmy moths (Insecta, Lepidoptera, Nepticulidae) discovered in the northern Andean bush and grass páramo and the central Andean puna at altitudes above 3700 m. They represent the world's highest-altitudinal Nepticulidae fauna known. The height record belongs to Stigmella nivea sp. nov. from Peru collected at an elevation of 4700 m. Except for one species, all belong to Stigmella Schrank. Twenty-two of the species recorded are new and are named and described in the current paper: Stigmella paramica Diškus & Stonis, sp. nov.; S. lachemillae Diškus & Stonis, sp. nov.; S. gynoxyphaga Diškus & Stonis, sp. nov.; S. calceolariae Diškus & Stonis, sp. nov.; S. rigida Diškus & Stonis, sp. nov.; S. altiplanica Diškus & Stonis, sp. nov.; S. robusta Remeikis & Stonis, sp. nov.; S. pseudorobusta Remeikis & Stonis, sp. nov.; S. auriargentata Remeikis & Stonis, sp. nov.; S. altimontana Remeikis & Stonis, sp. nov.; S. pandora Remeikis & Stonis, sp. nov.; S. ampla Diškus & Stonis, sp. nov.; S. evanida Diškus & Stonis, sp. nov.; S. mustelina Remeikis & Stonis, sp. nov.; S. angusta Diškus & Stonis, sp. nov.; S. alticosma Remeikis & Stonis, sp. nov.; S. nivea Remeikis & Stonis, sp. nov.; S. kristenseni Diškus & Stonis, sp. nov.; S. lobata Remeikis & Stonis, sp. nov.; S. ageratinae Diškus & Stonis, sp. nov.; S. clinopodiella Diškus & Stonis, sp. nov.; and S. calceolarifoliae Diškus & Stonis, sp. nov. Some of these species are leaf-miners on Asteraceae (Pentacalia, Baccharis, Gynoxys, and Ageratina plants), Calceolariaceae (Calceolaria), Lamiaceae (Clinopodium), and Rosaceae (Lachemilla). Twenty species are known only from adults with no data on their biology and host-plants. In addition, we present data and discuss recently discovered nepticulid taxa associated with Polylepis forests that is the natural vegetation in much of the High Andes. All High-Andean Stigmella species treated are illustrated with photographs of the adults and genitalia, distribution maps, including some with photographs of the leaf-mines and habitats.

First discovery of Quercus feeding Nepticulidae (Lepidoptera) in Central America.

PubMed

Stonis, Jonas R; Diškus, Arūnas; Remeikis, Andrius; Schuster, Jack

2013-11-18

Despite the high taxonomic diversity of oaks in Mexico and Central America, no Quercus feeding Nepticulidae have ever been recorded from the region. Here, we present seven species whose larvae are leaf-miners of Quercus (section Lobatae) in Guatemala. Except Stigmella nigriverticella (Chambers 1875), which was previously known from the United States, all other discovered species are new. We describe and name five new species (Stigmella jaguari Remeikis & Stonis, sp. nov., S. lauta Diškus & Stonis, sp. nov., S. sublauta Remeikis & Stonis, sp. nov., S. aurifasciata Diškus & Stonis, sp. nov. and S. guatemalensis Diškus & Stonis, sp. nov.); the remaining new species is described but left unnamed because of lack of adults (i. e. moths and genitalia are described from developed pupae). All seven treated species are illustrated with photographs of the leaf-mines, adults, and genitalia.

The effect of crop protection strategy on pest and beneficials incidence in protected crops.

PubMed

Lourenço, I; Rodrigues, S; Figueiredo, E; Godinho, M C; Marques, C; Amaro, F; Mexia, A

2002-01-01

This study took place in the Oeste region from 1996-1999 and it intended to analyse if the crop protection strategy followed by the farmer influenced the arthropod incidence and the natural control in protected vegetable crops under Mediterranean conditions. The observations were made fortnightly (Autumn/Winter) or weekly (Spring/Summer) in 30-60 plants/parcel (1 plant/35 m2) in order to evaluate incidences. Samples of pests and natural enemies were collected for systematic identification in two greenhouses for each protection strategy (traditional chemical control (TCC), integrated pest management (IPM) and pest control allowed in organic farming (OF)) in lettuce, tomato, green beans and cucumber. Data on incidence of mites, aphids, caterpillars, leafminers, whiteflies, thrips and respective natural enemies were registered as well as phytosanitary treatments performed (farmers' information and/or in loco traces). The leafminers were the pest whose incidence more often presented significant statistical differences between the studied protection strategies. In relation to this pest, the main results obtained were: a higher feeding punctures incidence in TCC than in IPM; higher incidence of adults, mines and feeding punctures in TCC than in OF; and a higher mines' incidence in IPM than in OF. Both in TCC and IPM high percentages of plants with mines were found although without an adult proportional presence. In the first case this was due to the repeatedly phytosanitary treatments applied; in the second case it was due to the natural control, since in IPM and OF greenhouses the collected larvae were mostly parasitized or dead. In spite of the fact these two strategies have as final result a similar mines and adults incidence, their production and environmental costs are quite different. Significant differences at the beneficials' population level between TCC greenhouses and IPM or OF greenhouses were found. As the farmers did no biological treatments these differences are related to different levels of beneficial populations due to different secondary effects of the pesticides applied.

Residues of diflubenzuron on horse chestnut (Aesculus hippocastanum) leaves and their efficacy against the horse chestnut leafminer, Cameraria ohridella.

PubMed

Nejmanová, Jana; Cvacka, Josef; Hrdý, Ivan; Kuldová, Jelena; Mertelík, Josef; Muck, Alexander; Nesnerová, Petra; Svatos, Ales

2006-03-01

Residues of the insect growth regulator diflubenzuron were quantified on horse chestnut (Aesculus hippocastanum L.) leaves treated with a diflubenzuron 480 g litre(-1) SC, Dimilin. To analyse the samples, an analytical procedure was developed involving a simple extraction step followed by high-performance liquid chromatography on an octadecyl-modified silica column with methanol + 0.01 M ammonium acetate mobile phase. The results showed diflubenzuron to be highly stable on horse chestnut leaves; more than 4 months (127 days) after application, 38% (on average) of the insecticide still remained on/in the leaves. The data confirmed biological observations showing diflubenzuron's long-term efficacy against the horse chestnut leafminer, Cameraria ohridella Deschka and Dimić, which is the most important pest of the horse chestnut in Europe. The hypothesis of possible penetration of diflubenzuron into the leaf mass is explored and discussed.

Complex Feeding Tracks of the Sessile Herbivorous Insect Ophiomyia maura as a Function of the Defense against Insect Parasitoids

PubMed Central

Ayabe, Yoshiko; Ueno, Takatoshi

2012-01-01

Because insect herbivores generally suffer from high mortality due to their natural enemies, reducing the risk of being located by natural enemies is of critical importance for them, forcing them to develop a variety of defensive measures. Larvae of leaf-mining insects lead a sedentary life inside a leaf and make conspicuous feeding tracks called mines, exposing themselves to the potential risk of parasitism. We investigated the defense strategy of the linear leafminer Ophiomyia maura Meigen (Diptera: Agromyzidae), by focusing on its mining patterns. We examined whether the leafminer could reduce the risk of being parasitized (1) by making cross structures in the inner area of a leaf to deter parasitoids from tracking the mines due to complex pathways, and (2) by mining along the edge of a leaf to hinder visually searching parasitoids from finding mined leaves due to effective background matching of the mined leaves among intact leaves. We quantified fractal dimension as mine complexity and area of mine in the inner area of the leaf as interior mine density for each sample mine, and analyzed whether these mine traits affected the susceptibility of O. maura to parasitism. Our results have shown that an increase in mine complexity with the development of occupying larvae decreases the probability of being parasitized, while interior mine density has no influence on parasitism. These results suggest that the larval development increases the host defense ability through increasing mine complexity. Thus the feeding pattern of these sessile insects has a defensive function by reducing the risk of parasitism. PMID:22393419

Phytosanitary irradiation of Liriomyza trifolii (Diptera: Agromyzidae)

USDA-ARS?s Scientific Manuscript database

Agromyzid leafminers are economic and quarantine pests of a variety of vegetables, flowers and ornamental foliage. Methyl bromide fumigation is often used as a phytosanitary treatment when quarantined agromyzids are found in shipped commodities; alternative treatments are sought. Ionizing radiation...

Determining Plant – Leaf Miner – Parasitoid Interactions: A DNA Barcoding Approach

PubMed Central

Derocles, Stéphane A. P.; Evans, Darren M.; Nichols, Paul C.; Evans, S. Aifionn; Lunt, David H.

2015-01-01

A major challenge in network ecology is to describe the full-range of species interactions in a community to create highly-resolved food-webs. We developed a molecular approach based on DNA full barcoding and mini-barcoding to describe difficult to observe plant – leaf miner – parasitoid interactions, consisting of animals commonly regarded as agricultural pests and their natural enemies. We tested the ability of universal primers to amplify the remaining DNA inside leaf miner mines after the emergence of the insect. We compared the results of a) morphological identification of adult specimens; b) identification based on the shape of the mines; c) the COI Mini-barcode (130 bp) and d) the COI full barcode (658 bp) fragments to accurately identify the leaf-miner species. We used the molecular approach to build and analyse a tri-partite ecological network of plant – leaf miner – parasitoid interactions. We were able to detect the DNA of leaf-mining insects within their feeding mines on a range of host plants using mini-barcoding primers: 6% for the leaves collected empty and 33% success after we observed the emergence of the leaf miner. We suggest that the low amplification success of leaf mines collected empty was mainly due to the time since the adult emerged and discuss methodological improvements. Nevertheless our approach provided new species-interaction data for the ecological network. We found that the 130 bp fragment is variable enough to identify all the species included in this study. Both COI fragments reveal that some leaf miner species could be composed of cryptic species. The network built using the molecular approach was more accurate in describing tri-partite interactions compared with traditional approaches based on morphological criteria. PMID:25710377

Mating disruption of citrus leafminer mediated by a noncompetitive mechanism at a remarkably low pheromone release rate.

PubMed

Stelinski, L L; Miller, J R; Rogers, M E

2008-08-01

The citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is a worldwide pest of citrus. A season-long investigation was conducted that evaluated mating disruption for this pest. Effective disruption of the male P. citrella orientation to pheromone traps (98%) and reduced flush infestation by larvae was achieved for 221 d with two deployments of a 3:1 blend of (Z,Z,E)-7,11,13-hexadecatrienal/(Z,Z)-7,11-hexadecadienal at a remarkably low rate of 1.5 g active ingredient (AI)/ha per deployment. To gain insight into the mechanism that mediates the disruption of P. citrella, male moth catch was quantified in replicated plots of citrus treated with varying densities of pheromone dispensers. The densities of septum dispensers compared were: 0 (0/ha, 0.0 g AI/ha), 0.2 (one every fifth tree or 35/ha, 0.05 g AI/ha), 1 (215/ha, 0.29 g AI/ha), and 5 per tree (1,100/ha, 1.5 g AI/ha). Profile analysis by previously published mathematical methods matched predictions of noncompetitive mating disruption. Behavioral observations of male P. citrella in the field revealed that males did not approach mating disruption dispensers in any of the dispenser density treatments. The current report presents the first set of profile analyses combined with direct behavioral observations consistent with previously published theoretical predictions for a noncompetitive mechanism of mating disruption. The results suggest that disruption of P. citrella should be effective even at high population densities given the density-independent nature of disruption for this species and the remarkably low rate of pheromone per hectare required for efficacy.

Integrated Management of Citrus Canker

USDA-ARS?s Scientific Manuscript database

Fruit losses due to citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), vary each crop season depending on citrus variety, tree age, flushing condition, leafminer control, and coincidence of weather events with occurrence of susceptible fruit and foliage. In 2012, crop losses in Hamlin f...

Research progress for integrated canker management

USDA-ARS?s Scientific Manuscript database

Fruit losses due to citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), vary each crop season depending on citrus variety, tree age, flushing condition, leafminer control, and coincidence of weather events with occurrence of susceptible fruit and foliage. In 2013, crop losses in Hamlin f...

A Global Phylogeny of Leafmining Ectoedemia Moths (Lepidoptera: Nepticulidae): Exploring Host Plant Family Shifts and Allopatry as Drivers of Speciation

PubMed Central

Doorenweerd, Camiel; van Nieukerken, Erik J.; Menken, Steph B. J.

2015-01-01

Background Host association patterns in Ectoedemia (Lepidoptera: Nepticulidae) are also encountered in other insect groups with intimate plant relationships, including a high degree of monophagy, a preference for ecologically dominant plant families (e.g. Fagaceae, Rosaceae, Salicaceae, and Betulaceae) and a tendency for related insect species to feed on related host plant species. The evolutionary processes underlying these patterns are only partly understood, we therefore assessed the role of allopatry and host plant family shifts in speciation within Ectoedemia. Methodology Six nuclear and mitochondrial DNA markers with a total aligned length of 3692 base pairs were used to infer phylogenetic relationships among 92 species belonging to the subgenus Ectoedemia of the genus Ectoedemia, representing a thorough taxon sampling with a global coverage. The results support monophyletic species groups that are congruent with published findings based on morphology. We used the obtained phylogeny to explore host plant family association and geographical distribution to investigate if host shifts and allopatry have been instrumental in the speciation of these leafmining insects. Significance We found that, even though most species within species groups commonly feed on plants from one family, shifts to a distantly related host family have occasionally occurred throughout the phylogeny and such shifts are most commonly observed towards Betulaceae. The largest radiations have occurred within species groups that feed on Fagaceae, Rosaceae, and Salicaceae. Most species are restricted to one of the seven global biogeographic regions, but within species groups representatives are commonly found in different biogeographic regions. Although we find general patterns with regard to host use and biogeography, there are differences between clades that suggest that different drivers of speciation, and perhaps drivers that we did not examine, have shaped diversity patterns in different clades. PMID:25785630

The leafmining Leurocephala schinusae (Lepidoptera Gracillariidae): Not suitable for the biological control of Schinus terebinthifolius (Sapindales Anacardiaceae)in continental USA

USDA-ARS?s Scientific Manuscript database

Leurocephala schinusae Davis & Mc Kay (Lepidoptera: Gracillariidae) was studied to assess its suitability as a biological control agent of Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae), a serious environmental weed in the USA and elsewhere in the world. The host range was determined by ...

Biology and life history of Argopistes tsekooni (Coleoptera: Chrysomelidae) in China, a promising biological control agent of Chinese privet.

Treesearch

Y-Z Zhang; J. Sun; J.L. Hanula

2009-01-01

The biology and life history of Argopistes tsekooni Chen (Coleoptera: Chrysomelidae), a potential biological control agent of Chinese privet, Ligustrum sinense Lour., was studied under laboratory and outdoor conditions in Huangshan City of Anhui Province, China, in 2006. A. tsekooni larvae are leafminers that...

Sensory imbalance as mechanism of orientation disruption in the leafminer, Phyllocnistis citrella: Elucidation by multivariate geometric designs and response surface models

USDA-ARS?s Scientific Manuscript database

Experimental designs developed to address mixtures are ideally suited for many areas of experimental biology including pheromone blend studies because they address the confounding of proportionality and concentration intrinsic to factorial and one-factor-at-a-time designs. Geometric multivariate des...

Host range of the European leaf sheath mining midge, Lasioptera donacis Coutin, a biological control of giant reed, Arundo donax

USDA-ARS?s Scientific Manuscript database

The fundamental host range of the arundo leafminer, Lasioptera donacis a candidate agent for the invasive weed, Arundo donax was evaluated. Lasioptera donacis collects and inserts spores of a saprophytic fungus, Arthrinium arundinis, during oviposition. Larvae feed and develop in the decomposing le...

Evidence for ecological speciation via a host shift in the holly leafminer, Phytomyza glabricola (Diptera: Agromyzidae)

USDA-ARS?s Scientific Manuscript database

Evolutionary radiations have been well documented in plants and insects, but we have yet to determine the relative impact of genetic drift and natural selection underlying these radiations. If radiations are adaptive, the diversity of species could be due to ecological speciation in these lineages. ...

Description of the last-instar larva and pupa of a leaf-mining hispine - Prionispa champaka Maulik, 1919 (Coleoptera, Chrysomelidae, Cassidinae, Oncocephalini).

PubMed

Liao, Chengqing; Liu, Peng; Xu, Jiasheng; Staines, Charles L; Dai, Xiaohua

2018-01-01

The last-instar larva and pupa of Prionispa champaka Maulik, 1919 are described and figured in detail. The chaetotaxy of the head, mouthparts, legs, and dorsal and ventral surfaces of the body are given. The larva of P. champaka mine in the leaves of Pollia japonica Thunb. (Commelinaceae) and pupate in the base of the mid-ribs. The adults were also observed feeding on the leaves of Pollia siamensis (Carib.) Faden ex D. Y. Hong. The prominent diagnostic characters of immature stages of other species of the three genera of Oncocephalini ( Prionispa , Chaeridiona , and Oncocephala ) are discussed.

New taxa, including three new genera show uniqueness of Neotropical Nepticulidae (Lepidoptera)

PubMed Central

van Nieukerken, Erik J.; Doorenweerd, Camiel; Nishida, Kenji; Snyers, Chris

2016-01-01

Abstract After finding distinct clades in a molecular phylogeny for Nepticulidae that could not be placed in any known genera and discovering clear apomorphic characters that define these clades, as well as a number of Neotropical species that could be placed in known genera but were undescribed, three new genera and nine new species are here described from the Neotropics: Stigmella gallicola van Nieukerken & Nishida, sp. n. reared from galls on Hampea appendiculata (Malvaceae) in Costa Rica, representing the first example of a gall making Stigmella; Stigmella schinivora van Nieukerken, sp. n. reared from leafmines on Schinus terebinthifolia (Anacardiaceae) in Argentina, Misiones; Stigmella costaricensis van Nieukerken & Nishida, sp. n. and Stigmella intronia van Nieukerken & Nishida, sp. n. each from a single specimen collected the same night in Costa Rica, Parque Nacional Chirripó; Stigmella molinensis van Nieukerken & Snyers, sp. n. reared from leafmines on Salix humboldtiana, Peru, Lima, the first Neotropical species of the Stigmella salicis group sensu stricto; Ozadelpha van Nieukerken, gen. n. with type species Ozadelpha conostegiae van Nieukerken & Nishida, sp. n., reared from leafmines on Conostegia oerstediana (Melastomataceae) from Costa Rica; Neotrifurcula van Nieukerken, gen. n. with type species Neotrifurcula gielisorum van Nieukerken, sp. n. from Chile; Hesperolyra van Nieukerken, gen. n.. with type species Fomoria diskusi Puplesis & Robinson, 2000; Hesperolyra saopaulensis van Nieukerken, sp. n., reared from an unidentified Myrtaceae, Sao Paulo, Brasil; and Acalyptris janzeni van Nieukerken & Nishida, sp. n. from Costa Rica, Guanacaste. Five new combinations are made: Ozadelpha ovata (Puplesis & Robinson, 2000), comb. n. and Ozadelpha guajavae (Puplesis & Diškus, 2002), comb. n., Hesperolyra diskusi (Puplesis & Robinson, 2000), comb. n., Hesperolyra molybditis (Zeller, 1877), comb. n. and Hesperolyra repanda (Puplesis & Diškus, 2002), comb. n. Three specimens are briefly described, but left unnamed: Ozadelpha specimen EvN4680, Neotrifurcula specimen EvN4504 and Neotrifurcula specimen RH2. PMID:27917037

Biology and systematics of the leafmining Gracillariidae of Brazilian pepper tree, Schinus terebinthifolius Raddi, with descriptions of a new genus and four new species

USDA-ARS?s Scientific Manuscript database

Recent surveys in southern Florida, USA, Brazil and Argentina, for biological control agents to assist in the control of the invasive Brazilian peppertree, have discovered several previously unknown species of plant mining Lepidoptera of the family Gracillariidae. Morphological descriptions with sum...

Phytomyza omlandi spec. nov. – the first species of Agromyzidae (Diptera: Schizophora) reared from the family Gelsemiaceae (Asteridae)

USDA-ARS?s Scientific Manuscript database

A new species of leafmining fly in the genus Phytomyza Fallén (Diptera: Agromyzidae) is described from Gelsemium Juss, representing the first known instance of an agromyzid feeding on Gelsemiaceae (Asteridae). The host plant, G. sempervirens (L.) (the “evening trumpetflower”), and possibly also G. r...

Biotic and abiotic factors influencing infestation levels of the arundo leafminer, Lasioptera donacis, in its native range in Mediterranean Europe

USDA-ARS?s Scientific Manuscript database

Lasioptera donacis is a biological control agent of Arundo donax, which is an invasive weed in the riparian habitats of the Rio Grande Basin of Texas and Northern Mexico. Field research was conducted in the native range of L. donacis in Mediterranean Europe to evaluate the biotic and abiotic factor...

Repeated climate-linked host shifts have promoted diversification in a temperate clade of leaf-mining flies

PubMed Central

Winkler, Isaac S.; Mitter, Charles; Scheffer, Sonja J.

2009-01-01

A central but little-tested prediction of “escape and radiation” coevolution is that colonization of novel, chemically defended host plant clades accelerates insect herbivore diversification. That theory, in turn, exemplifies one side of a broader debate about the relative influence on clade dynamics of intrinsic (biotic) vs. extrinsic (physical-environmental) forces. Here, we use a fossil-calibrated molecular chronogram to compare the effects of a major biotic factor (repeated shift to a chemically divergent host plant clade) and a major abiotic factor (global climate change) on the macroevolutionary dynamics of a large Cenozoic radiation of phytophagous insects, the leaf-mining fly genus Phytomyza (Diptera: Agromyzidae). We find one of the first statistically supported examples of consistently elevated net diversification accompanying shift to new plant clades. In contrast, we detect no significant direct effect on diversification of major global climate events in the early and late Oligocene. The broader paleoclimatic context strongly suggests, however, that climate change has at times had a strong indirect influence through its effect on the biotic environment. Repeated rapid Miocene radiation of these flies on temperate herbaceous asterids closely corresponds to the dramatic, climate-driven expansion of seasonal, open habitats. PMID:19805134

Spatial distribution and sequential sampling plans for Tuta absoluta (Lepidoptera: Gelechiidae) in greenhouse tomato crops.

PubMed

Cocco, Arturo; Serra, Giuseppe; Lentini, Andrea; Deliperi, Salvatore; Delrio, Gavino

2015-09-01

The within- and between-plant distribution of the tomato leafminer, Tuta absoluta (Meyrick), was investigated in order to define action thresholds based on leaf infestation and to propose enumerative and binomial sequential sampling plans for pest management applications in protected crops. The pest spatial distribution was aggregated between plants, and median leaves were the most suitable sample to evaluate the pest density. Action thresholds of 36 and 48%, 43 and 56% and 60 and 73% infested leaves, corresponding to economic thresholds of 1 and 3% damaged fruits, were defined for tomato cultivars with big, medium and small fruits respectively. Green's method was a more suitable enumerative sampling plan as it required a lower sampling effort. Binomial sampling plans needed lower average sample sizes than enumerative plans to make a treatment decision, with probabilities of error of <0.10. The enumerative sampling plan required 87 or 343 leaves to estimate the population density in extensive or intensive ecological studies respectively. Binomial plans would be more practical and efficient for control purposes, needing average sample sizes of 17, 20 and 14 leaves to take a pest management decision in order to avoid fruit damage higher than 1% in cultivars with big, medium and small fruits respectively. © 2014 Society of Chemical Industry.

Oxygen enhances phosphine toxicity for postharvest pest control.

PubMed

Liu, Yong-Biao

2011-10-01

Phosphine fumigations under superatmospheric oxygen levels (oxygenated phosphine fumigations) were significantly more effective than the fumigations under the normal 20.9% atmospheric oxygen level against western flower thrips [Frankliniella occidentalis (Pergande)] adults and larvae, leafminer Liriomyza langei Frick pupae, grape mealybug [Pseudococcus maritimus (Ehrhorn)] eggs, and Indianmeal moth [Plodia interpunctella (Hübner)] eggs and pupae. In 5-h fumigations with 1,000 ppm phosphine at 5 degrees C, mortalities of western flower thrips increased significantly from 79.5 to 97.7% when oxygen was increased from 20.9 to 40% and reached 99.3% under 80% O2. Survivorships of leafminer pupae decreased significantly from 71.2% under 20.9% O2 to 16.2% under 40% O2 and reached 1.1% under 80% O2 in 24-h fumigations with 500 ppm phosphine at 5 degrees C. Complete control of leafminer pupae was achieved in 24-h fumigations with 1,000 ppm phosphine at 5 degrees C under 60% O2 or higher. Survivorships of grape mealybug eggs also decreased significantly in 48-h fumigations with 1,000 ppm phosphine at 2 degrees C under 60% O2 compared with the fumigations under 20.9% O2. Indian meal moth egg survivorships decreased significantly from 17.4 to 0.5% in responses to an oxygen level increase from 20.9 to 40% in 48-h fumigations with 1,000 ppm phosphine at 10 degrees C and reached 0.2% in fumigations under 80% O2. When the oxygen level was reduced from 20.9 to 15 and 10% in fumigations, survivorships of Indianmeal moth eggs increased significantly from 17.4 to 32.9 and 39.9%, respectively. Increased O2 levels also resulted in significantly lower survival rates of Indianmeal moth pupae in response to 24-h fumigations with 500 and 1,000 ppm phosphine at 10 degrees C and a complete control was achieved in the 1,000 ppm phosphine fumigations under 60% O2. Oxygenated phosphine fumigations have marked potential to improve insecticidal efficacy. Advantages and limitations of oxygenated phosphine fumigation are discussed.

New Contributions to Pseudonapomyza (Diptera: Agromyzidae) from Spain: Addition of Three New Species

PubMed Central

Gil-Ortiz, Ricardo; Martinez, Michel; Jiménez-Peydró, Ricardo

2010-01-01

The genus Pseudonapomyza (Diptera: Agromyzidae) includes the main leafminer pests for monocots. Three new species are described that were captured using Malaise traps in “Tinença de Benifassà”, “Font Roja” and “Lagunas de La Mata-Torrevieja” (Spain) Natural Parks: Pseudonapomyza curvata n. sp., P. longitata n. sp., and P. sicicornis n. sp. Systematics. Ecological data are discussed. PMID:21062209

A preliminary molecular phylogeny of shield-bearer moths (Lepidoptera: Adeloidea: Heliozelidae) highlights rich undescribed diversity.

PubMed

Milla, Liz; van Nieukerken, Erik J; Vijverberg, Ruben; Doorenweerd, Camiel; Wilcox, Stephen A; Halsey, Mike; Young, David A; Jones, Therésa M; Kallies, Axel; Hilton, Douglas J

2018-03-01

Heliozelidae are a widespread, evolutionarily early diverging family of small, day-flying monotrysian moths, for which a comprehensive phylogeny is lacking. We generated the first molecular phylogeny of the family using DNA sequences of two mitochondrial genes (COI and COII) and two nuclear genes (H3 and 28S) from 130 Heliozelidae specimens, including eight of the twelve known genera: Antispila, Antispilina, Coptodisca, Heliozela, Holocacista, Hoplophanes, Pseliastis, and Tyriozela. Our results provide strong support for five major Heliozelidae clades: (i) a large widespread clade containing the leaf-mining genera Antispilina, Coptodisca and Holocacista and some species of Antispila, (ii) a clade containing most of the described Antispila, (iii) a clade containing the leaf-mining genus Heliozela and the monotypic genus Tyriozela, (iv) an Australian clade containing Pseliastis and (v) an Australian clade containing Hoplophanes. Each clade includes several new species and potentially new genera. Collectively, our data uncover a rich and undescribed diversity that appears to be especially prevalent in Australia. Our work highlights the need for a major taxonomic revision of the family and for generating a robust molecular phylogeny using multi-gene approaches in order to resolve the relationships among clades. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Additive effects of vertebrate predators on insects in a Puerto Rican coffee plantation

USGS Publications Warehouse

Borkhataria, R.R.; Collazo, J.A.; Groom, Martha J.

2006-01-01

A variety of studies have established the value of shaded coffee plantations as habitat for birds. While the value of birds as biological controls in coffee has received some attention, the interactions between birds and other predators of insects have not been tested. We used exclosures to examine the effects of vertebrate predators on the arthropods associated with coffee, in particular the coffee leafminer (Leucoptera coffeella) and the flatid planthopper Petrusa epilepsis, in a shaded coffee plantation in Puerto Rico. We used a 2 x 2 factorial design with four treatments: exclusion of birds, lizards, birds and lizards, and control (no exclusion). Abundance of insects >5 mm increased when birds or both birds and lizards were removed. Birds and lizards had an additive effect for insects <5 mm and for all insects combined. Coffee leafminers showed a weak response to removal of predators while planthopper abundance increased significantly in the absence of avian predators. Arthropod predators and parasitoids did not differ significantly between treatments. Our findings suggest that vertebrate insectivores have an additive effect on insects in coffee and may help control abundances of some coffee pests. Equally important, we present evidence suggesting that they do not interfere with other known natural enemies of coffee pests. ?? 2006 by the Ecological Society of America.

Fortuitous establishment of Ageniaspis citricola (Hymenoptera: Encyrtidae) in Jamaica on the citrus leafminer (Lepidoptera: Gracillariidae)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoy, M.A.; Jeyaprakash, A.; Clarke-Harris, D.

These data indicate that the population of A. citricola in Jamaica probably originated from the Australian (Thailand), rather than from the Taiwan, population. This is consistent with what is currently known about the origin of the established Ageniaspis population in Florida (Alvarez 2000). It is not known when, or how, A. citricola arrived in Jamaica, although the CLM was detected there in 1994. The fortuitous establishment of A. citricolaon the CLM in Jamaica is not the only such establishment of a natural enemy discovered during this 2004 survey of citrus. The parasitoid Lipolexis oregmae Gahan (Hymenoptera: Aphidiidae) was found attackingmore » the brown citrus aphid, Toxoptera citricida Kirkaldy (Hemiptera: Aphididae) (Hoy et al., unpublished data), and the eulophid parasitoid Tamarixia radiata Waterston was found attacking the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae). The fact that 3 natural enemies of 3 invasive citrus pests were found in Jamaica, none of which were purposefully imported and released, suggests that pest-infested citrus trees were imported into Jamaica without going through appropriate quarantine procedures. Because each pest arrived at different times, the parasitoids probably arrived at different times, as well. This indicates that an analysis is needed to identify the critical control points within those services in Jamaica that support border protection, and that procedures may require strengthening. (author)« less

Mitochondrial and microsatellite DNA markers reveal a Balkan origin for the highly invasive horse-chestnut leaf miner Cameraria ohridella (Lepidoptera, Gracillariidae).

PubMed

Valade, R; Kenis, M; Hernandez-Lopez, A; Augustin, S; Mari Mena, N; Magnoux, E; Rougerie, R; Lakatos, F; Roques, A; Lopez-Vaamonde, C

2009-08-01

Biological invasions usually start with a small number of founder individuals. These founders are likely to represent a small fraction of the total genetic diversity found in the source population. Our study set out to trace genetically the geographical origin of the horse-chestnut leafminer, Cameraria ohridella, an invasive microlepidopteran whose area of origin is still unkown. Since its discovery in Macedonia 25 years ago, this insect has experienced an explosive westward range expansion, progressively colonizing all of Central and Western Europe. We used cytochrome oxidase I sequences (DNA barcode fragment) and a set of six polymorphic microsatellites to assess the genetic variability of C. ohridella populations, and to test the hypothesis that C. ohridella derives from the southern Balkans (Albania, Macedonia and Greece). Analysis of mtDNA of 486 individuals from 88 localities allowed us to identify 25 geographically structured haplotypes. In addition, 480 individuals from 16 populations from Europe and the southern Balkans were genotyped for 6 polymorphic microsatellite loci. High haplotype diversity and low measures of nucleotide diversities including a significantly negative Tajima's D indicate that C. ohridella has experienced rapid population expansion during its dispersal across Europe. Both mtDNA and microsatellites show a reduction in genetic diversity of C. ohridella populations sampled from artificial habitats (e.g. planted trees in public parks, gardens, along roads in urban or sub-urban areas) across Europe compared with C. ohridella sampled in natural stands of horse-chestnuts in the southern Balkans. These findings suggest that European populations of C. ohridella may indeed derive from the southern Balkans.

Population Development of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) under Simulated UK Glasshouse Conditions

PubMed Central

Cuthbertson, Andrew G.S.; Mathers, James J.; Blackburn, Lisa F.; Korycinska, Anastasia; Luo, Weiqi; Jacobson, Robert J.; Northing, Phil

2013-01-01

Tomato leafminer Tuta absoluta (Meyrick) is a major pest of tomato plants in South America. It was first recorded in the UK in 2009 where it has been subjected to eradication policies. The current work outlines T. absoluta development under various UK glasshouse temperatures. The optimum temperature for Tuta development ranged from 19–23 °C. At 19 °C, there was 52% survival of T. absoluta from egg to adult. As temperature increased (23 °C and above) development time of the moth would appear to decrease. Population development ceases between 7 and 10 °C. Only 17% of eggs hatched at 10 °C but no larvae developed through to adult moths. No eggs hatched when maintained at 7 °C. Under laboratory conditions the total lifespan of the moth was longest (72 days) at 13 °C and shortest (35 days) at both 23 and 25 °C. Development from egg to adult took 58 days at 13 °C; 37 days at 19 °C and 23 days at 25 °C. High mortality of larvae occurred under all temperatures tested. First instar larvae were exposed on the leaf surface for approximately 82 minutes before fully tunnelling into the leaf. Adult longevity was longest at 10 °C with moths living for 40 days and shortest at 19 °C where they survived for 16 days. Generally more males than females were produced. The potential of Tuta absoluta to establish populations within UK protected horticulture is discussed. PMID:26464384

Genetic variation in foundation species governs the dynamics of trophic interactions

PubMed Central

Valencia-Cuevas, Leticia; Mussali-Galante, Patricia; Cano-Santana, Zenón; Pujade-Villar, Juli; Equihua-Martínez, Armando

2018-01-01

Abstract Various studies have demonstrated that the foundation species genetic diversity can have direct effects that extend beyond the individual or population level, affecting the dependent communities. Additionally, these effects may be indirectly extended to higher trophic levels throughout the entire community. Quercus castanea is an oak species with characteristics of foundation species beyond presenting a wide geographical distribution and being a dominant element of Mexican temperate forests. In this study, we analyzed the influence of population (He) and individual (HL) genetic diversity of Q. castanea on its canopy endophagous insect community and associated parasitoids. Specifically, we studied the composition, richness (S) and density of leaf-mining moths (Lepidoptera: Tischeridae, Citheraniidae), gall-forming wasps (Hymenoptera: Cynipidae), and canopy parasitoids of Q. castanea. We sampled 120 trees belonging to six populations (20/site) through the previously recognized gradient of genetic diversity. In total, 22 endophagous insect species belonging to three orders (Hymenoptera, Lepidoptera, and Diptera) and 20 parasitoid species belonging to 13 families were identified. In general, we observed that the individual genetic diversity of the host plant (HL) has a significant positive effect on the S and density of the canopy endophagous insect communities. In contrast, He has a significant negative effect on the S of endophagous insects. Additionally, indirect effects of HL were observed, affecting the S and density of parasitoid insects. Our results suggest that genetic variation in foundation species can be one of the most important factors governing the dynamics of tritrophic interactions that involve oaks, herbivores, and parasitoids. PMID:29492034

Use of Monoclonal Antibodies in an ELISA for Detecting an Invasive Pest Insect, Liriomyza trifolii (Diptera: Agromyzidae).

PubMed

Zhao, W C; Shang, H W; Guo, W; Xu, D; Huang, T Y; Zhu, L X

2015-04-01

A monoclonal antibody was prepared by the hybridoma technology. It reacted only with the protein of Liriomyza trifolii (Burgess) and not with that of Chromatomyia horticola Goureau or Liriomyza sativae Blanchard in indirect enzyme-linked immunosorbent assay. It was effective even after being diluted more than 8.192×10(6)-fold. The detection sensitivity of the antibody was 31.3 µg/ml under controlled conditions. Positive reaction was achieved with all laboratory-reared L. trifolii samples, including larvae, pupae, and adults. An indirect enzyme-linked immunosorbent assay system was successfully established to detect L. trifolii in the field. This antibody was successfully used to determine the L. trifolii collected in different locations, from different host plants, and in different seasons. More than 50% of leafminers collected on Brassica chinensis var chinensis, Apium graveolens (Miller) Persoon, Vigna unguiculata (L.) Walpers, Phaseolus vulgaris L., Lactuca sativa L., and Chrysanthemum coronarium (L.) Cassini ex Spach were L. trifolii, indicating that those six plant species might be the preference host plants of L. trifolii. Population of L. trifolii peaked in September, October, or November in Hangzhou, Zhejiang. These results suggest a great potential of using this McAb for precisely identifying L. trifolii and monitoring the population dynamics of L. trifolii in the field. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A revised checklist of Nepticulidae fossils (Lepidoptera) indicates an Early Cretaceous origin.

PubMed

Doorenweerd, Camiel; Nieukerken, Erik J Van; Sohn, Jae-Cheon; Labandeira, Conrad C

2015-05-27

With phylogenetic knowledge of Lepidoptera rapidly increasing, catalysed by increasingly powerful molecular techniques, the demand for fossil calibration points to estimate an evolutionary timeframe for the order is becoming an increasingly pressing issue. The family Nepticulidae is a species rich, basal branch within the phylogeny of the Lepidoptera, characterized by larval leaf-mining habits, and thereby represents a potentially important lineage whose evolutionary history can be established more thoroughly with the potential use of fossil calibration points. Using our experience with extant global Nepticulidae, we discuss a list of characters that may be used to assign fossil leaf mines to Nepticulidae, and suggest useful methods for classifying relevant fossil material. We present a checklist of 79 records of Nepticulidae representing adult and leaf-mine fossils mentioned in literature, often with multiple exemplars constituting a single record. We provide our interpretation of these fossils. Two species now are included in the collective generic name Stigmellites: Stigmellites resupinata (Krassilov, 2008) comb. nov. (from Ophiheliconoma) and Stigmellites almeidae (Martins-Neto, 1989) comb. nov. (from Nepticula). Eleven records are for the first time attributed to Nepticulidae. After discarding several dubious records, including one possibly placing the family at a latest Jurassic position, we conclude that the oldest fossils likely attributable to Nepticulidae are several exemplars representing a variety of species from the Dakota Formation (USA). The relevant strata containing these earliest fossils are now dated at 102 Ma (million years ago) in age, corresponding to the latest Albian Stage of the Early Cretaceous. Integration of all records in the checklist shows that a continuous presence of nepticulid-like leaf mines preserved as compression-impression fossils and by amber entombment of adults have a fossil record extending to the latest Early Cretaceous.

The Ando-Patagonian Stigmella magnispinella group (Lepidoptera, Nepticulidae) with description of new species from Ecuador, Peru and Argentina.

PubMed

Stonis, Jonas R; Remeikis, Andrius; Diškus, Arūnas; Gerulaitis, Virginijus

2016-12-01

On the basis of morphological studies of collection samples from the Andes (Ecuador, Peru and Argentina), we describe five new species of Stigmella Schrank (Lepidoptera: Nepticulidae): S. varispinella Diškus & Stonis, sp. nov. (Ecuador), S. olekarsholti Remeikis Diškus & Stonis, sp. nov., S. magnispinella Remeikis & Stonis, sp. nov. (Peru), S. dolia Remeikis & Stonis, sp. nov., and S. patagonica Remeikis & Stonis, sp. nov. (Argentina). All treated taxa belong to the newly designated S. magnispinella group. Images of adults and genitalia, pictorial keys, a distribution map, and photographs of the leaf-mines of S. olekarsholti are included.

Investigating dormant-season application of pheromone in citrus to control overwintering and spring populations of Phyllocnistis citrella (Lepidoptera: Gracillariidae).

PubMed

Keathley, Craig P; Stelinski, Lukasz L; Lapointe, Stephen L

2016-07-01

The leafminer, Phyllocnistis citrella Stainton, reproduces on leaf flush during winter. Deployment of pheromone during winter could suppress moth populations in spring and summer more than a spring application alone. We tested the primary pheromone component of P. citrella, (Z,Z,E)-7,11,13-hexadecatrienal, released gradually over several months from elastomeric dispensers in a citrus grove in 6.4 ha main plots in winter and/or 3.2 ha subplots in spring (834 mg triene ha(-1) ) and evaluated moth catch and leaf mining. After winter treatment, dispensers provided >85% disruption of male moth catch in traps for 37 weeks, and after spring treatment they provided >92% disruption for 26 weeks, but there was only a 12% reduction in leaf infestation in spring. Two applications were no better than only a single application in spring. Disruption of moth catch was weaker in treated plots where traps were placed high (3.1 m) rather than low (1.6 m) in the tree canopy. Dispensers provided effective and persistent disruption of male catch in pheromone-baited monitoring traps but were minimally effective in reducing leaf infestation by P. citrella. Winter application of pheromone did not reduce leaf mining in spring compared with spring application alone. Tops of trees may have provided a refuge for mating. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Population Growth Parameters of Tuta absoluta (Lepidoptera: Gelechiidae) on Tomato Plant Using Organic Substrate and Biofertilizers

PubMed Central

Razmjou, J.; Naseri, B.; Hassanpour, M.

2017-01-01

The tomato leafminer, Tuta absoluta (Meyrick) is a devastating pest associated with tomato. In this study, effects of tomato plants treated with vermicompost (20, 40, and 60%), humic fertilizer (2, 4 and 6 g/kg soil) and plant growth promoting rhizobacteria (Pseudomonas fluorescens and Bacillus subtilis) were investigated on the life table parameters of T. absoluta in a growth chamber at 25 ± 2 °C, 65 ± 5% RH, and 16:8 (L:D) h. Significant differences were found for the total developmental time, fecundity, and oviposition period of T. absoluta on the treatments tested. The net reproductive rate (R0), intrinsic rate of natural increase (rm), finite rate of increase (λ), mean generation time (T), and doubling time (DT) of T. absoluta were significantly different among treatments tested. We found that in all vermicompost, humic fertilizer and plant growth promoting rhizobacteria treatments, values of R0, rm, and λ were lower than control treatment. However, the lowest values of these parameters were obtained on 2 g/kg humic fertilizer and 40% vermicompost. Furthermore, T. absoluta had longest T and DT values on 2 g/kg humic fertilizer treatment. Data obtained showed that the addition of 2 g/kg humic fertilizer and 40% vermicompost to the growing soil reduced T. absoluta populations in tomato cultures. In addition, these levels of fertilizers improved growth parameters of tomato seedlings (plant height, wet weight, and dry weight) compared with other treatments. These results could be useful in improving the sustainable management of the moth. PMID:28355477

The Success of the Horse-Chestnut Leaf-Miner, Cameraria ohridella, in the UK Revealed with Hypothesis-Led Citizen Science

PubMed Central

Pocock, Michael J. O.; Evans, Darren M.

2014-01-01

Citizen science is an increasingly popular way of undertaking research and simultaneously engaging people with science. However, most emphasis of citizen science in environmental science is on long-term monitoring. Here, we demonstrate the opportunities provided by short-term hypothesis-led citizen science. In 2010, we ran the ‘Conker Tree Science’ project, in which over 3500 people in Great Britain provided data at a national scale of an insect (horse-chestnut leaf-mining moth, Cameraria ohridella) undergoing rapid range-expansion. We addressed two hypotheses, and found that (1) the levels of damage caused to leaves of the horse-chestnut tree, Aesculus hippocastanum, and (2) the level of attack by parasitoids of C. ohridella larvae were both greatest where C. ohridella had been present the longest. Specifically there was a rapid rise in leaf damage during the first three years that C. ohridella was present and only a slight rise thereafter, while estimated rates of parasitism (an index of true rates of parasitism) increased from 1.6 to 5.9% when the time C. ohridella had been present in a location increased from 3 to 6 years. We suggest that this increase is due to recruitment of native generalist parasitoids, rather than the adaptation or host-tracking of more specialized parasitoids, as appears to have occurred elsewhere in Europe. Most data collected by participants were accurate, but the counts of parasitoids from participants showed lower concordance with the counts from experts. We statistically modeled this bias and propagated this through our analyses. Bias-corrected estimates of parasitism were lower than those from the raw data, but the trends were similar in magnitude and significance. With appropriate checks for data quality, and statistically correcting for biases where necessary, hypothesis-led citizen science is a potentially powerful tool for carrying out scientific research across large spatial scales while simultaneously engaging many people with science. PMID:24465973

The success of the horse-chestnut leaf-miner, Cameraria ohridella, in the UK revealed with hypothesis-led citizen science.

PubMed

Pocock, Michael J O; Evans, Darren M

2014-01-01

Citizen science is an increasingly popular way of undertaking research and simultaneously engaging people with science. However, most emphasis of citizen science in environmental science is on long-term monitoring. Here, we demonstrate the opportunities provided by short-term hypothesis-led citizen science. In 2010, we ran the 'Conker Tree Science' project, in which over 3500 people in Great Britain provided data at a national scale of an insect (horse-chestnut leaf-mining moth, Cameraria ohridella) undergoing rapid range-expansion. We addressed two hypotheses, and found that (1) the levels of damage caused to leaves of the horse-chestnut tree, Aesculus hippocastanum, and (2) the level of attack by parasitoids of C. ohridella larvae were both greatest where C. ohridella had been present the longest. Specifically there was a rapid rise in leaf damage during the first three years that C. ohridella was present and only a slight rise thereafter, while estimated rates of parasitism (an index of true rates of parasitism) increased from 1.6 to 5.9% when the time C. ohridella had been present in a location increased from 3 to 6 years. We suggest that this increase is due to recruitment of native generalist parasitoids, rather than the adaptation or host-tracking of more specialized parasitoids, as appears to have occurred elsewhere in Europe. Most data collected by participants were accurate, but the counts of parasitoids from participants showed lower concordance with the counts from experts. We statistically modeled this bias and propagated this through our analyses. Bias-corrected estimates of parasitism were lower than those from the raw data, but the trends were similar in magnitude and significance. With appropriate checks for data quality, and statistically correcting for biases where necessary, hypothesis-led citizen science is a potentially powerful tool for carrying out scientific research across large spatial scales while simultaneously engaging many people with science.

Nitrogen nutrition of tomato plant alters leafminer dietary intake dynamics.

PubMed

Coqueret, Victoire; Le Bot, Jacques; Larbat, Romain; Desneux, Nicolas; Robin, Christophe; Adamowicz, Stéphane

2017-05-01

The leafminer Tuta absoluta (Meyrick) is a major pest of the tomato crop and its development rate is known to decline when nitrogen availability for crop growth is limited. Because N limitation reduces plant primary metabolism but enhances secondary metabolism, one can infer that the slow larval development arises from lower leaf nutritive value and/or higher plant defence. As an attempt to study the first alternative, we examined the tomato-T. absoluta interaction in terms of resource supply by leaves and intake by larvae. Tomato plants were raised under controlled conditions on N-sufficient vs. N-limited complete nutrient solutions. Plants were kept healthy or artificially inoculated with larvae for seven days. Serial harvests were taken and the N, C, dry mass and water contents were determined in roots, stems and leaves. Leaf and mine areas were also measured and the N, C, dry mass and water surface densities were calculated in order to characterize the diet of the larvae. The infestation of a specific leaf lessened its local biomass by 8-26%, but this effect was undetectable at the whole plant scale. Infestation markedly increased resource density per unit leaf area (water, dry mass, C and N) suggesting that the insect induced changes in leaf composition. Nitrogen limitation lessened whole plant growth (by 50%) and infested leaflet growth (by 32-44%). It produced opposite effects on specific resource density per unit area, increasing that of dry mass and C while decreasing water and N. These changes were ineffective on insect mining activity, but slowed down larval development. Under N limitation, T. absoluta consumed less water and N but more dry mass and C. The resulting consequences were a 50-70% increase of C:N stoichiometry in their diet and the doubling of faeces excretion. The observed limitation of larval development is therefore consistent with a trophic explanation caused by low N and/or water intakes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel Insect Leaf-Mining after the End-Cretaceous Extinction and the Demise of Cretaceous Leaf Miners, Great Plains, USA

PubMed Central

Donovan, Michael P.; Wilf, Peter; Labandeira, Conrad C.; Johnson, Kirk R.; Peppe, Daniel J.

2014-01-01

Plant and associated insect-damage diversity in the western U.S.A. decreased significantly at the Cretaceous-Paleogene (K-Pg) boundary and remained low until the late Paleocene. However, the Mexican Hat locality (ca. 65 Ma) in southeastern Montana, with a typical, low-diversity flora, uniquely exhibits high damage diversity on nearly all its host plants, when compared to all known local and regional early Paleocene sites. The same plant species show minimal damage elsewhere during the early Paleocene. We asked whether the high insect damage diversity at Mexican Hat was more likely related to the survival of Cretaceous insects from refugia or to an influx of novel Paleocene taxa. We compared damage on 1073 leaf fossils from Mexican Hat to over 9000 terminal Cretaceous leaf fossils from the Hell Creek Formation of nearby southwestern North Dakota and to over 9000 Paleocene leaf fossils from the Fort Union Formation in North Dakota, Montana, and Wyoming. We described the entire insect-feeding ichnofauna at Mexican Hat and focused our analysis on leaf mines because they are typically host-specialized and preserve a number of diagnostic morphological characters. Nine mine damage types attributable to three of the four orders of leaf-mining insects are found at Mexican Hat, six of them so far unique to the site. We found no evidence linking any of the diverse Hell Creek mines with those found at Mexican Hat, nor for the survival of any Cretaceous leaf miners over the K-Pg boundary regionally, even on well-sampled, surviving plant families. Overall, our results strongly relate the high damage diversity on the depauperate Mexican Hat flora to an influx of novel insect herbivores during the early Paleocene, possibly caused by a transient warming event and range expansion, and indicate drastic extinction rather than survivorship of Cretaceous insect taxa from refugia. PMID:25058404

Population Growth Parameters of Tuta absoluta (Lepidoptera: Gelechiidae) on Tomato Plant Using Organic Substrate and Biofertilizers.

PubMed

Mohamadi, P; Razmjou, J; Naseri, B; Hassanpour, M

2017-01-01

The tomato leafminer, Tuta absoluta (Meyrick) is a devastating pest associated with tomato. In this study, effects of tomato plants treated with vermicompost (20, 40, and 60%), humic fertilizer (2, 4 and 6 g/kg soil) and plant growth promoting rhizobacteria (Pseudomonas fluorescens and Bacillus subtilis) were investigated on the life table parameters of T. absoluta in a growth chamber at 25 ± 2 °C, 65 ± 5% RH, and 16:8 (L:D) h. Significant differences were found for the total developmental time, fecundity, and oviposition period of T. absoluta on the treatments tested. The net reproductive rate (R0), intrinsic rate of natural increase (rm), finite rate of increase (λ), mean generation time (T), and doubling time (DT) of T. absoluta were significantly different among treatments tested. We found that in all vermicompost, humic fertilizer and plant growth promoting rhizobacteria treatments, values of R0, rm, and λ were lower than control treatment. However, the lowest values of these parameters were obtained on 2 g/kg humic fertilizer and 40% vermicompost. Furthermore, T. absoluta had longest T and DT values on 2 g/kg humic fertilizer treatment. Data obtained showed that the addition of 2 g/kg humic fertilizer and 40% vermicompost to the growing soil reduced T. absoluta populations in tomato cultures. In addition, these levels of fertilizers improved growth parameters of tomato seedlings (plant height, wet weight, and dry weight) compared with other treatments. These results could be useful in improving the sustainable management of the moth. © The Author 2017. Published by Oxford University Press on behalf of the Entomological Society of America.

Imidacloprid soil movement under micro-sprinkler irrigation and soil-drench applications to control Asian citrus psyllid (ACP) and citrus leafminer (CLM).

PubMed

Fletcher, Evelyn; Morgan, Kelly T; Qureshi, Jawwad A; Leiva, Jorge A; Nkedi-Kizza, Peter

2018-01-01

Imidacloprid (IM) is used to control the Asian Citrus Psyllid (ACP) and citrus leafminer (CLM), which are related to the spread of huanglongbing (HLB or citrus greening) and citrus canker diseases, respectively. In Florida citrus, imidacloprid is mainly soil-drenched around the trees for proper root uptake and translocation into plant canopy to impact ACP and CLM. The objective of this study was to determine the effect of imidacloprid rate, and irrigate amount on concentration of imidacloprid in the soil following drench application to citrus trees in three age classes. The plots were established at the Southwest Florida Research and Education Center, Immokalee, using a randomized complete-block design for three age classes of trees: one-year-old trees (B1), three to five-year-old trees (B2), and eight-year-old trees (B3). The treatments were a combination of two rates each of imidacloprid (1D, 2D) and micro-sprinkling irrigation (1I, 2I). Imidacloprid and bromide (Br-) used as tracer were applied simultaneously. Soil moisture and concentrations of imidacloprid and Br were monitored using soil cores from hand held augers. Soil moisture content (θV) did not differ under two irrigation rates at any given observation day or depth, except following heavy rainfall events. Br- was lost from the observation depths (0-45 cm) about two weeks after soil-drench. Contrarily, imidacloprid persisted for a much longer time (4-8 weeks) at all soil depths, regardless of treatment combinations. The higher retardation of imidacloprid was related to the predominantly unsaturated conditions of the soil (which in turn reduced soil hydraulic conductivities by orders of magnitude), the imidacloprid sorption on soil organic matter, and the citrus root uptake. Findings of this study are important for citrus growers coping with the citrus greening and citrus canker diseases because they suggest that imidacloprid soil drenches can still be an effective control measure of ACP and CLM, and the potential for imidacloprid leaching to groundwater is minimal.

Imidacloprid soil movement under micro-sprinkler irrigation and soil-drench applications to control Asian citrus psyllid (ACP) and citrus leafminer (CLM)

PubMed Central

Fletcher, Evelyn; Qureshi, Jawwad A.; Leiva, Jorge A.; Nkedi-Kizza, Peter

2018-01-01

Imidacloprid (IM) is used to control the Asian Citrus Psyllid (ACP) and citrus leafminer (CLM), which are related to the spread of huanglongbing (HLB or citrus greening) and citrus canker diseases, respectively. In Florida citrus, imidacloprid is mainly soil-drenched around the trees for proper root uptake and translocation into plant canopy to impact ACP and CLM. The objective of this study was to determine the effect of imidacloprid rate, and irrigate amount on concentration of imidacloprid in the soil following drench application to citrus trees in three age classes. The plots were established at the Southwest Florida Research and Education Center, Immokalee, using a randomized complete-block design for three age classes of trees: one-year-old trees (B1), three to five-year-old trees (B2), and eight-year-old trees (B3). The treatments were a combination of two rates each of imidacloprid (1D, 2D) and micro-sprinkling irrigation (1I, 2I). Imidacloprid and bromide (Br-) used as tracer were applied simultaneously. Soil moisture and concentrations of imidacloprid and Br were monitored using soil cores from hand held augers. Soil moisture content (θV) did not differ under two irrigation rates at any given observation day or depth, except following heavy rainfall events. Br- was lost from the observation depths (0–45 cm) about two weeks after soil-drench. Contrarily, imidacloprid persisted for a much longer time (4–8 weeks) at all soil depths, regardless of treatment combinations. The higher retardation of imidacloprid was related to the predominantly unsaturated conditions of the soil (which in turn reduced soil hydraulic conductivities by orders of magnitude), the imidacloprid sorption on soil organic matter, and the citrus root uptake. Findings of this study are important for citrus growers coping with the citrus greening and citrus canker diseases because they suggest that imidacloprid soil drenches can still be an effective control measure of ACP and CLM, and the potential for imidacloprid leaching to groundwater is minimal. PMID:29518086

Combined effects of environmental disturbance and climate warming on insect herbivory in mountain birch in subarctic forests: Results of 26-year monitoring.

PubMed

Kozlov, M V; Zverev, V; Zvereva, E L

2017-12-01

Both pollution and climate affect insect-plant interactions, but the combined effects of these two abiotic drivers of global change on insect herbivory remain almost unexplored. From 1991 to 2016, we monitored the population densities of 25 species or species groups of insects feeding on mountain birch (Betula pubescens ssp. czerepanovii) in 29 sites and recorded leaf damage by insects in 21 sites in subarctic forests around the nickel-copper smelter at Monchegorsk, north-western Russia. The leaf-eating insects demonstrated variable, and sometimes opposite, responses to pollution-induced forest disturbance and to climate variations. Consequently, we did not discover any general trend in herbivory along the disturbance gradient. Densities of eight species/species groups correlated with environmental disturbance, but these correlations weakened from 1991 to 2016, presumably due to the fivefold decrease in emissions of sulphur dioxide and heavy metals from the smelter. The densities of externally feeding defoliators decreased from 1991 to 2016 and the densities of leafminers increased, while the leaf roller densities remained unchanged. Consequently, no overall temporal trend in the abundance of birch-feeding insects emerged despite a 2-3°C elevation in spring temperatures. Damage to birch leaves by insects decreased during the observation period in heavily disturbed forests, did not change in moderately disturbed forests and tended to increase in pristine forests. The temporal stability of insect-plant interactions, quantified by the inverse of the coefficient of among-year variations of herbivore population densities and of birch foliar damage, showed a negative correlation with forest disturbance. We conclude that climate differently affects insect herbivory in heavily stressed versus pristine forests, and that herbivorous insects demonstrate diverse responses to environmental disturbance and climate variations. This diversity of responses, in combination with the decreased stability of insect-plant interactions, increases the uncertainty in predictions on the impacts of global change on forest damage by insects. Copyright © 2017 Elsevier B.V. All rights reserved.

Changes in host-parasitoid food web structure with elevation.

PubMed

Maunsell, Sarah C; Kitching, Roger L; Burwell, Chris J; Morris, Rebecca J

2015-03-01

Gradients in elevation are increasingly used to investigate how species respond to changes in local climatic conditions. Whilst many studies have shown elevational patterns in species richness and turnover, little is known about how food web structure is affected by elevation. Contrasting responses of predator and prey species to elevation may lead to changes in food web structure. We investigated how the quantitative structure of a herbivore-parasitoid food web changes with elevation in an Australian subtropical rain forest. On four occasions, spread over 1 year, we hand-collected leaf miners at twelve sites, along three elevational gradients (between 493 m and 1159 m a.s.l). A total of 5030 insects, including 603 parasitoids, were reared, and summary food webs were created for each site. We also carried out a replicated manipulative experiment by translocating an abundant leaf-mining weevil Platynotocis sp., which largely escaped parasitism at high elevations (≥ 900 m a.s.l.), to lower, warmer elevations, to test if it would experience higher parasitism pressure. We found strong evidence that the environmental change that occurs with increasing elevation affects food web structure. Quantitative measures of generality, vulnerability and interaction evenness decreased significantly with increasing elevation (and decreasing temperature), whilst elevation did not have a significant effect on connectance. Mined plant composition also had a significant effect on generality and vulnerability, but not on interaction evenness. Several relatively abundant species of leaf miner appeared to escape parasitism at higher elevations, but contrary to our prediction, Platynotocis sp. did not experience greater levels of parasitism when translocated to lower elevations. Our study indicates that leaf-mining herbivores and their parasitoids respond differently to environmental conditions imposed by elevation, thus producing structural changes in their food webs. Increasing temperatures and changes in vegetation communities that are likely to result from climate change may have a restructuring effect on host-parasitoid food webs. Our translocation experiment, however, indicated that leaf miners currently escaping parasitism at high elevations may not automatically experience higher parasitism under warmer conditions and future changes in food web structure may depend on the ability of parasitoids to adapt to novel hosts. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Geographic variation in apparent competition between native and invasive Phragmites australis.

PubMed

Bhattarai, Ganesh P; Meyerson, Laura A; Cronin, James T

2017-02-01

Apparent competition, the negative interaction between species mediated by shared natural enemies, is thought to play an important role in shaping the structure and dynamics of natural communities. However, its importance in driving species invasions, and whether the strength of this indirect interaction varies across the latitudinal range of the invasion, has not been fully explored. We performed replicated field experiments at four sites spanning 900 km along the Atlantic Coast of the United States to assess the presence and strength of apparent competition between sympatric native and invasive lineages of Phragmites australis. Four herbivore guilds were considered: stem-feeders, leaf-miners, leaf-chewers and aphids. We also tested the hypothesis that the strength of this interaction declines with increasing latitude. Within each site, native and invasive plants of P. australis were cross-transplanted between co-occurring native and invasive patches in the same marsh habitat and herbivore damage was evaluated at the end of the growing season. Apparent competition was evident for both lineages and involved all but the leaf-chewer guild. For native plants, total aphids per plant was 296% higher and the incidence of stem-feeding and leaf-mining herbivores was 34% and 221% higher, respectively, when transplanted into invasive than native patches. These data suggest that invasive P. australis has a negative effect on native P. australis via apparent competition. Averaged among herbivore types, the indirect effects of the invasive lineage on the native lineage was 57% higher than the reverse situation, suggesting that apparent competition was asymmetric. We also found that the strength of apparent competition acting against the native lineage was comparable to the benefits to the invasive lineage from enemy release (i.e., proportionately lower mean herbivory of the invasive relative to the native taxa). Finally, we found the first evidence that the strength of apparent competition acting against the native lineage (from stem-feeders only) decreased with increasing latitude. These results suggest that not only could apparent competition be of tantamount importance to enemy release in enhancing the establishment and spread of invasive taxa, but also that these indirect and direct herbivore effects could vary over the invasion range. © 2016 by the Ecological Society of America.

Stenochironomus munteanpurin sp. n., a new leaf-mining species from Brazil (Diptera: Chironomidae).

PubMed

Amora, Gizelle; Hamada, Neusa; Pinho, Luiz C

2018-02-21

Stenochironomus munteanpurin sp. n. is described and illustrated in all life stages, except eggs, from Brazil. The male is very similar to Stenochironomus quadrinotatus Borkent, 1984 due to same overall pattern of pigmentation. The new species can be distinguished from the other related species principally in immature stages: larva with labral lamella arranged in two groups with one or two conical-shaped teeth, spicules of pecten epipharyngis arranged in a row, unequal and irregularly distributed sizes, SI bifurcated, SII pinnate, SIII pinnate setae and, larval exuviae is compacted; pupa with shagreens being in all TI, less number of hooklets in TII, TVII without shagreens and presence of shagreen in conjunctive III/IV and IV/V. Adult male is very similar to the one of S. quadrinotatus but can be distinguished by combination of the TIX with more than 25 setae medially and phallapodeme curved anteriorly. The new species were collected in the following Brazilian states: Rio de Janeiro, Santa Catarina, Bahia and Acre.

Spatial distribution of parasitism on Phyllocnistis citrella Stainton, 1856 (Lepidoptera: Gracillariidae) in citrus orchards.

PubMed

Jahnke, S M; Redaelli, L R; Diefenbach, L M G; Efrom, C F

2008-11-01

Many species of microhymenopterous parasitoids have been registered on Phyllocnistis citrella, the citrus leafminer. The present study aimed to identify the spatial distribution pattern of the native and introduced parasitoids of P. citrella in two citrus orchards in Montenegro, RS. The new shoots from 24 randomly selected trees in each orchard were inspected at the bottom (0-1.5 m) and top (1.5-2.5 m) stratum and had their position relative to the quadrants (North, South, East and West) registered at every 15 days from July/2002 to June/2003. The leaves with pupae were collected and kept isolated until the emergence of parasitoids or of the leaf miner; so, the sampling was biased towards parasitoids that emerge in the host pupal phase. The horizontal spatial distribution was evaluated testing the fitness of data to the Poisson and negative binomial distributions. In Montenegrina, there was no significant difference in the number of parasitoids and in the mean number of pupae found in the top and bottom strata (chi2 = 0.66; df = 1; P > 0.05) (chi2 = 0.27; df =1; P > 0.05), respectively. In relation to the quadrants, the highest average numbers of the leafminer pupae and of parasitoids were registered at the East quadrant (chi2 = 11.81; df = 3; P < 0.05), (chi2 = 10.36; df = 3; P < 0.05). In the Murcott orchard, a higher number of parasitoids was found at the top stratum (63.5%) (chi2 = 7.24; df =1 P < 0.05), the same occurring with the average number of P. citrella pupae (62.9%) (chi2 = 6.66; df = 1; P < 0.05). The highest number of parasitoids and of miners was registered at the North quadrant (chi2 = 19. 29; df = 3; P < 0.05), (chi2 = 4.39; df = 3; P < 0.05). In both orchards, there was no difference between the numbers of shoots either relative to the strata as well as to the quadrants. As the number of shoots did not varied much relative to the quadrants, it is possible that the higher number of miners and parasitoids in the East and West quadrants would be influenced by the higher solar exposure of these quadrants. The data of the horizontal spatial distribution of the parasitism fit to the negative binomial distribution in all sampling occasions, indicating an aggregated pattern.

Phylogeny and host-plant relationships of the Australian Myrtaceae leafmining moth genus Pectinivalva (Lepidoptera, Nepticulidae), with new subgenera and species

PubMed Central

Hoare, Robert J.B.; van Nieukerken, Erik J.

2013-01-01

Abstract The phylogeny of the mainly Australian nepticulid genus Pectinivalva Scoble, 1983 is investigated on the basis of morphology, and a division into three monophyletic subgenera is proposed on the basis of these results. These subgenera (Pectinivalva, Casanovula Hoare, subgen. n. and Menurella Hoare, subgen. n. ) are described and diagnosed, the described species of Pectinivalva are assigned to them, and representative new species are described in each: Pectinivalva (Pectinivalva) mystaconota Hoare, sp. n., Pectinivalva (Casanovula) brevipalpa Hoare, sp. n., Pectinivalva (Casanovula) minotaurus Hoare, sp. n., Pectinivalva (Menurella) scotodes Hoare, sp. n., Pectinivalva (Menurella) acmenae Hoare, sp. n., Pectinivalva (Menurella) xenadelpha Van Nieukerken & Hoare, sp. n., Pectinivalva (Menurella) quintiniae Hoare & Van Nieukerken, sp. n., and Pectinivalva (Menurella) tribulatrix Van Nieukerken & Hoare, sp. n. Pectinivalva (Menurella) quintiniae (from Quintinia verdonii, Paracryphiaceae) is the first known member of the genus with a host-plant not belonging to Myrtaceae. Pectinivalva (Menurella) xenadelpha from Mt Gunung Lumut, Kalimantan, Borneo, is the first pectinivalvine reported from outside Australia. Keys to the subgenera of Nepticulidae known from Australia, based on adults, male and female genitalia, and larvae, are presented. Host-plant relationships of Pectinivalva are discussed with relation to the phylogeny, and a list of known host-plants of Pectinivalva, including hosts of undescribed species, is presented. DNA barcodes are provided for most of the new and several unnamed species. PMID:23794827

Emamectin, a novel insecticide for controlling field crop pests.

PubMed

Ishaaya, Isaac; Kontsedalov, Svetlana; Horowitz, A Rami

2002-11-01

Emamectin is a macrocyclic lactone insecticide with low toxicity to non-target organisms and the environment, and is considered an important component in pest-management programmes for controlling field crop pests. It is a powerful compound for controlling the cotton bollworm Helicoverpa armigera (Hübner). A spray concentration of 25 mg AI litre-1 in a cotton field resulted in over 90% suppression of H armigera larvae up to day 28 after treatment, while similar mortality of the Egyptian cotton leafworm Spodoptera littoralis Boisduval, under the same conditions, was maintained for 3 days only. Emamectin is a potent compound for controlling the western flower thrips Frankliniella occidentalis (Pergande) under both laboratory and field conditions and its activity on adults was over 10-fold greater than that of abamectin. Spray concentrations of 10 and 50 mg AI litre-1 in Ageratum houstonianum Mill flowers resulted in total suppression of adults up to day 11 and of larvae up to day 20 after treatment. Under standard laboratory conditions, emamectin exhibits a considerable activity on the whitefly Bemisia tabaci (Gennadius) and the leafminer Liriomyza huidobrensis (Blanchard). Further studies are required to evaluate its potential activity on the latter pests under field conditions.

Water relations and microclimate around the upper limit of a cloud forest in Maui, Hawai'i.

PubMed

Gotsch, Sybil G; Crausbay, Shelley D; Giambelluca, Thomas W; Weintraub, Alexis E; Longman, Ryan J; Asbjornsen, Heidi; Hotchkiss, Sara C; Dawson, Todd E

2014-07-01

The goal of this study was to determine the effects of atmospheric demand on both plant water relations and daily whole-tree water balance across the upper limit of a cloud forest at the mean base height of the trade wind inversion in the tropical trade wind belt. We measured the microclimate and water relations (sap flow, water potential, stomatal conductance, pressure-volume relations) of Metrosideros polymorpha Gaudich. var. polymorpha in three habitats bracketing the cloud forest's upper limit in Hawai'i to understand the role of water relations in determining ecotone position. The subalpine shrubland site, located 100 m above the cloud forest boundary, had the highest vapor pressure deficit, the least amount of rainfall and the highest levels of nighttime transpiration (EN) of all three sites. In the shrubland site, on average, 29% of daily whole-tree transpiration occurred at night, while on the driest day of the study 50% of total daily transpiration occurred at night. While EN occurred in the cloud forest habitat, the proportion of total daily transpiration that occurred at night was much lower (4%). The average leaf water potential (Ψleaf) was above the water potential at the turgor loss point (ΨTLP) on both sides of the ecotone due to strong stomatal regulation. While stomatal closure maintained a high Ψleaf, the minimum leaf water potential (Ψleafmin) was close to ΨTLP, indicating that drier conditions may cause drought stress in these habitats and may be an important driver of current landscape patterns in stand density. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Biology and systematics of the New World Phyllocnistis Zeller leafminers of the avocado genus Persea (Lepidoptera, Gracillariidae)

PubMed Central

Davis, Donald R.; Wagner, David L.

2011-01-01

Abstract Four New World species of Phyllocnistis Zeller are described from serpentine mines in Persea (Family Lauraceae). Phyllocnistis hyperpersea,new species, mines the upper leaf surfaces of avocado, Persea americana Mill., and red bay, Persea borbonia (L.) Spreng. and ranges over much of the southeastern United States into Central America. Phyllocnistis subpersea,new species, mines the underside and occasionally upper sides of new leaves of Persea borbonia in southeastern United States. Phyllocnistis longipalpa, new species, known only from southern Florida also mines the undersides of new leaves of Persea borbonia. Phyllocnistis perseafolia,new species, mines both leaf surfaces and possibly fruits of Persea americana in Colombia, South America. As in all known species of Phyllocnistis, the early instars are subepidermal sapfeeders in young (not fully hardened) foliage, and the final instar is an extremely specialized, nonfeeding larval form, whose primary function is to spin the silken cocoon, at the mine terminus, prior to pupation. Early stages are illustrated and described for three of the species. The unusual morphology of the pupae, particularly the frontal process of the head, is shown to be one of the most useful morphological sources of diagnostic characters for species identification of Phyllocnistis. COI barcode sequence distances are provided for the four proposed species and a fifth, undescribed species from Costa Rica. PMID:21594066

Biology and systematics of the New World Phyllocnistis Zeller leafminers of the avocado genus Persea (Lepidoptera, Gracillariidae).

PubMed

Davis, Donald R; Wagner, David L

2011-05-11

Four New World species of Phyllocnistis Zeller are described from serpentine mines in Persea (Family Lauraceae). Phyllocnistis hyperpersea,new species, mines the upper leaf surfaces of avocado, Persea americana Mill., and red bay, Persea borbonia (L.) Spreng. and ranges over much of the southeastern United States into Central America. Phyllocnistis subpersea,new species, mines the underside and occasionally upper sides of new leaves of Persea borbonia in southeastern United States. Phyllocnistis longipalpa, new species, known only from southern Florida also mines the undersides of new leaves of Persea borbonia. Phyllocnistis perseafolia,new species, mines both leaf surfaces and possibly fruits of Persea americana in Colombia, South America. As in all known species of Phyllocnistis, the early instars are subepidermal sapfeeders in young (not fully hardened) foliage, and the final instar is an extremely specialized, nonfeeding larval form, whose primary function is to spin the silken cocoon, at the mine terminus, prior to pupation. Early stages are illustrated and described for three of the species. The unusual morphology of the pupae, particularly the frontal process of the head, is shown to be one of the most useful morphological sources of diagnostic characters for species identification of Phyllocnistis. COI barcode sequence distances are provided for the four proposed species and a fifth, undescribed species from Costa Rica.

Insect Fauna Associated With Anacardium occidentale (Sapindales: Anacardiaceae) in Benin, West Africa

PubMed Central

Agboton, C.; Onzo, A.; Ouessou, F. I.; Goergen, G.; Vidal, S.; Tamò, M.

2014-01-01

Abstract Cashew, Anacardium occidentale L. (Sapindales: Anacardiaceae), is an important cash crop in Benin. However, its production is threatened by several biotic factors, especially insects. In Benin, very few studies have focused on insects and just listed species commonly found on cashew worldwide. The present investigation fills this gap by presenting an exhaustive inventory of insect species associated with this crop in the country. The survey was carried out from September 2009 to August 2010 in 22 cashew orchards (5 young and 17 mature) distributed over three major agroecological zones where cashew is most produced in the country. Insects were collected using chemical knock-down technique and visual observation followed by capture with sweep net. In addition, infested plant organs were sampled and incubated to collect emerging insects. In total, 262 insect species were recorded and identified. Among them, the wood borer Apate terebrans Pallas, the leafminer Eteoryctis gemoniella Stainton, and the mirid bugs Helopeltis schoutedeni Reuter., and Helopeltis anacardii Miller., appeared as the most important insect species attacking cashew in Benin. Beneficial insects encountered included some predators, parasitoids, and pollinators. Few vertebrate predators were also recorded on the trees. Differences in agroecological conditions or in field cleanliness did not affect the number of insect species encountered in the cashew orchards. The results of this study represent an important baseline data for the design and implementation of strategies for cashew protection in Benin. PMID:25434033

A signature of tree health? Shifts in the microbiome and the ecological drivers of horse chestnut bleeding canker disease.

PubMed

Koskella, Britt; Meaden, Sean; Crowther, William J; Leimu, Roosa; Metcalf, C Jessica E

2017-07-01

Host susceptibility to pathogens can be shaped by genetic, ecological, and evolutionary factors. The ability to predict the spread of disease therefore requires an integrated understanding of these factors, including effects of pests on pathogen growth and competition between pathogens and commensal microbiota for host resources. We examined interactions between the leaf-mining moth Cameraria ohridella, the bacterial causal agent of bleeding canker disease Pseudomonas syringae pv aesculi, and the bark-associated microbiota of horse chestnut (Aesculus hippocastanum) trees. Through surveys of > 900 trees from 60 sites in the UK, we tested for ecological or life history predictors of leaf miner infestation, bleeding canker, or coinfection. Using culture-independent sequencing, we then compared the bark microbiomes from 46 trees to measure the association between microbiome composition and key ecological variables, including the severity of disease. Both pest and pathogen were found to respond to tree characteristics, but neither explained damage inflicted by the other. However, we found a clear loss of microbial diversity and associated shift in microbiome composition of trees as a function of disease. These results show a link between bark-associated microbiota and tree health that introduces the intriguing possibility that tree microbiota play key roles in the spread of disease. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

A Burst of miRNA Innovation in the Early Evolution of Butterflies and Moths

PubMed Central

Quah, Shan; Hui, Jerome H.L.; Holland, Peter W.H.

2015-01-01

MicroRNAs (miRNAs) are involved in posttranscriptional regulation of gene expression. Because several miRNAs are known to affect the stability or translation of developmental regulatory genes, the origin of novel miRNAs may have contributed to the evolution of developmental processes and morphology. Lepidoptera (butterflies and moths) is a species-rich clade with a well-established phylogeny and abundant genomic resources, thereby representing an ideal system in which to study miRNA evolution. We sequenced small RNA libraries from developmental stages of two divergent lepidopterans, Cameraria ohridella (Horse chestnut Leafminer) and Pararge aegeria (Speckled Wood butterfly), discovering 90 and 81 conserved miRNAs, respectively, and many species-specific miRNA sequences. Mapping miRNAs onto the lepidopteran phylogeny reveals rapid miRNA turnover and an episode of miRNA fixation early in lepidopteran evolution, implying that miRNA acquisition accompanied the early radiation of the Lepidoptera. One lepidopteran-specific miRNA gene, miR-2768, is located within an intron of the homeobox gene invected, involved in insect segmental and wing patterning. We identified cubitus interruptus (ci) as a likely direct target of miR-2768, and validated this suppression using a luciferase assay system. We propose a model by which miR-2768 modulates expression of ci in the segmentation pathway and in patterning of lepidopteran wing primordia. PMID:25576364

The Invasive Liriomyza huidobrensis (Diptera: Agromyzidae): Understanding Its Pest Status and Management Globally

PubMed Central

Scheffer, Sonja J.; Visser, Diedrich; Valladares, Graciela; Soares Correa, Alberto; Shepard, B. Merle; Rauf, Aunu; Murphy, Sean T.; Mujica, Norma; MacVean, Charles; Kroschel, Jürgen; Kishinevsky, Miriam; Joshi, Ravindra C.; Johansen, Nina S.; Hallett, Rebecca H.; Civelek, Hasan S.; Chen, Bing; Metzler, Helga Blanco

2017-01-01

Liriomyza huidobrensis (Blanchard) is native to South America but has expanded its range and invaded many regions of the world, primarily on flowers and to a lesser extent on horticultural product shipments. As a result of initial invasion into an area, damage caused is usually significant but not necessarily sustained. Currently, it is an economic pest in selected native and invaded regions of the world. Adults cause damage by puncturing abaxial and adaxial leaf surfaces for feeding and egg laying sites. Larvae mine the leaf parenchyma tissues which can lead to leaves drying and wilting. We have recorded 365 host plant species from 49 families and more than 106 parasitoid species. In a subset of the Argentinian data, we found that parasitoid community composition attacking L. huidobrensis differs significantly in cultivated and uncultivated plants. No such effect was found at the world level, probably due to differences in collection methods in the different references. We review the existing knowledge as a means of setting the context for new and unpublished data. The main objective is to provide an update of widely dispersed and until now unpublished data, evaluate dispersion of the leafminer and management strategies in different regions of the world, and highlight the need to consider the possible effects of climate change on further regional invasions or expansions. PMID:28423426

Abamectin, pymetrozine and azadirachtin sequence as a unique solution to control the leafminer Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) infesting garden beans (Phaseolus vulgaris L.) in Egypt.

PubMed

Saad, A S A; Massoud, M A; Abdel-Megeed, A A M; Hamid, N A; Mourad, A K K; Barakat, A S T

2007-01-01

Field trails were conducted to determine the performance of three different sequences as a unique solution for the control of the leaf miner Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) infesting garden beans (Phaseolus vulgaris L.) during the two successive seasons of 2004 and 2005. Furthermore, during the evaluation period, the side effect against the ectoparasite Diglyphus isaea (Walker) (Hymenoptera: Eulophidae) was put into consideration. Meanwhile, the comparative evaluation of the pesticides alone showed that abamectin and azadirachtin were highly effective against Liriomyza trifolii, while carbosulfan, pymetrozine and thiamethoxam provided to be of a moderate effect. Moreover, carbosulfan showed harmful effect to the larvae of the ectoparasite Diglyphus isaea (Walker), while abamectin and azadirachtin gave a moderate effect. Thiamethoxam and the the detergent (Masrol 410) had slight effect in this respect. The highly effective sequence among the sequences was abamectin, pymetrozine and azadirachtin, against Liriomyza trifolii (Burgess), with slight harmful effect on Diglyphus isaea (Walker). However the sequence of azadirachtin, pymetrozine and abamectin had a moderate effect on Liriomyza trifolii (Burgess) and exhibited a slight toxic effect on Diglyphus isaea (Walker). In contrast, the sequence of carbosulfan, thiamethoxam and pymetrozine was the least effective and represented a slight effect on Diglyphus isaea (Walker). From this study, it was concluded that abamectin, pymetrozine and azadirachtin sequence has proved to be a unique solution for the control of the leaf miner Liriomyza trifolii (Burgess) infesting garden beans (Phaseolus vulgaris L.) in Egypt.

Interrelated responses of tomato plants and the leaf miner Tuta absoluta to nitrogen supply.

PubMed

Larbat, R; Adamowicz, S; Robin, C; Han, P; Desneux, N; Le Bot, J

2016-05-01

Plant-insect interactions are strongly modified by environmental factors. This study evaluates the influence of nitrogen fertilisation on the tomato (Solanum lycopersicum L.) cv. Santa clara and the leafminer (Tuta absoluta (Meyrick), Lepidoptera: Gelechiidae). Greenhouse-grown tomato plants were fed hydroponically on a complete nutrient solution containing either a high nitrogen concentration (HN) sustaining maximum growth or a low nitrogen concentration (LN) limiting plant growth. Insect-free plants were compared with plants attacked by T. absoluta. Seven and 14 days after artificial oviposition leading to efficacious hatching and larvae development, we measured total carbon, nitrogen and soluble protein as well as defence compounds (phenolics, glycoalkaloids, polyphenol oxidase activity) in the HN versus LN plants. Only in the HN treatment did T. absoluta infestation slightly impair leaf growth and induce polyphenol oxidase (PPO) activity in the foliage. Neither the concentration of phenolic compounds and proteins nor the distribution of nitrogen within the plant was affected by T. absoluta infestation. In contrast, LN nutrition impaired T. absoluta-induced PPO activity. It decreased protein and total nitrogen concentration of plant organs and enhanced the accumulation of constitutive phenolics and tomatine. Moreover, LN nutrition impaired T. absoluta development by notably decreasing pupal weight and lengthening the development period from egg to adult. Adjusting the level of nitrogen nutrition may thus be a means of altering the life cycle of T. absoluta. This study provides a comprehensive dataset concerning interrelated responses of tomato plants and T. absoluta to nitrogen nutrition. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

Differential Responses of Herbivores and Herbivory to Management in Temperate European Beech

PubMed Central

Gossner, Martin M.; Pašalić, Esther; Lange, Markus; Lange, Patricia; Boch, Steffen; Hessenmöller, Dominik; Müller, Jörg; Socher, Stephanie A.; Fischer, Markus; Schulze, Ernst-Detlef; Weisser, Wolfgang W.

2014-01-01

Forest management not only affects biodiversity but also might alter ecosystem processes mediated by the organisms, i.e. herbivory the removal of plant biomass by plant-eating insects and other arthropod groups. Aiming at revealing general relationships between forest management and herbivory we investigated aboveground arthropod herbivory in 105 plots dominated by European beech in three different regions in Germany in the sun-exposed canopy of mature beech trees and on beech saplings in the understorey. We separately assessed damage by different guilds of herbivores, i.e. chewing, sucking and scraping herbivores, gall-forming insects and mites, and leaf-mining insects. We asked whether herbivory differs among different forest management regimes (unmanaged, uneven-aged managed, even-aged managed) and among age-classes within even-aged forests. We further tested for consistency of relationships between regions, strata and herbivore guilds. On average, almost 80% of beech leaves showed herbivory damage, and about 6% of leaf area was consumed. Chewing damage was most common, whereas leaf sucking and scraping damage were very rare. Damage was generally greater in the canopy than in the understorey, in particular for chewing and scraping damage, and the occurrence of mines. There was little difference in herbivory among differently managed forests and the effects of management on damage differed among regions, strata and damage types. Covariates such as wood volume, tree density and plant diversity weakly influenced herbivory, and effects differed between herbivory types. We conclude that despite of the relatively low number of species attacking beech; arthropod herbivory on beech is generally high. We further conclude that responses of herbivory to forest management are multifaceted and environmental factors such as forest structure variables affecting in particular microclimatic conditions are more likely to explain the variability in herbivory among beech forest plots. PMID:25119984

Volatile emissions from Aesculus hippocastanum induced by mining of larval stages of Cameraria ohridella influence oviposition by conspecific females.

PubMed

Johne, A Bettina; Weissbecker, Bernhard; Schütz, Stefan

2006-10-01

Larval stages of the horse chestnut leafminer Cameraria ohridella can completely destroy the surface of horse chestnut leaves, Aesculus hippocastanum. This study investigated the effect of the degree of leaf browning caused by the insect's larvae on olfactory detection, aggregation, and oviposition of C. ohridella adults. The influence of A. hippocastanum flower scent on oviposition of the first generation was also evaluated. Utilizing gas chromatography coupled with parallel detection by mass spectrometry and electroantennography (GC-MS/EAD), more than 30 compounds eliciting responses from antennae of C. ohridella were detected. Oviposition and mining by C. ohridella caused significant changes in the profile of leaf volatiles of A. hippocastanum. After oviposition and subsequent mining by early larval stages (L1-L3), substances such as benzaldehyde, 1,8-cineole, benzyl alcohol, 2-phenylethanol, methyl salicylate, (E)-beta-caryophyllene, and (E,E)-alpha-farnesene were emitted in addition to the compounds emitted by uninfested leaves. Insects were able to detect these compounds. The emitted amount of these substances increased with progressive larval development. During late larval stages (L4, L5) and severe loss of green leaf area, (E,E)-2,4-hexadienal, (E/Z)-linalool oxide (furanoid), nonanal, and decanal were also released by leaves. These alterations of the profile of volatiles caused modifications in aggregation of C. ohridella on leaves. In choice tests, leaves in early infestation stages showed no significant effect on aggregation, whereas insects avoided leaves in late infestation stages. Further choice tests with leaves treated with single compounds led to the identification of substances mediating an increase or decrease in oviposition.

Genes Involved in the Evolution of Herbivory by a Leaf-Mining, Drosophilid Fly

PubMed Central

Whiteman, Noah K.; Gloss, Andrew D.; Sackton, Timothy B.; Groen, Simon C.; Humphrey, Parris T.; Lapoint, Richard T.; Sønderby, Ida E.; Halkier, Barbara A.; Kocks, Christine; Ausubel, Frederick M.; Pierce, Naomi E.

2012-01-01

Herbivorous insects are among the most successful radiations of life. However, we know little about the processes underpinning the evolution of herbivory. We examined the evolution of herbivory in the fly, Scaptomyza flava, whose larvae are leaf miners on species of Brassicaceae, including the widely studied reference plant, Arabidopsis thaliana (Arabidopsis). Scaptomyza flava is phylogenetically nested within the paraphyletic genus Drosophila, and the whole genome sequences available for 12 species of Drosophila facilitated phylogenetic analysis and assembly of a transcriptome for S. flava. A time-calibrated phylogeny indicated that leaf mining in Scaptomyza evolved between 6 and 16 million years ago. Feeding assays showed that biosynthesis of glucosinolates, the major class of antiherbivore chemical defense compounds in mustard leaves, was upregulated by S. flava larval feeding. The presence of glucosinolates in wild-type (WT) Arabidopsis plants reduced S. flava larval weight gain and increased egg–adult development time relative to flies reared in glucosinolate knockout (GKO) plants. An analysis of gene expression differences in 5-day-old larvae reared on WT versus GKO plants showed a total of 341 transcripts that were differentially regulated by glucosinolate uptake in larval S. flava. Of these, approximately a third corresponded to homologs of Drosophila melanogaster genes associated with starvation, dietary toxin-, heat-, oxidation-, and aging-related stress. The upregulated transcripts exhibited elevated rates of protein evolution compared with unregulated transcripts. The remaining differentially regulated transcripts also contained a higher proportion of novel genes than the unregulated transcripts. Thus, the transition to herbivory in Scaptomyza appears to be coupled with the evolution of novel genes and the co-option of conserved stress-related genes. PMID:22813779

Shared weapons of blood- and plant-feeding insects: Surprising commonalities for manipulating hosts.

PubMed

Guiguet, Antoine; Dubreuil, Géraldine; Harris, Marion O; Appel, Heidi M; Schultz, Jack C; Pereira, Marcos H; Giron, David

2016-01-01

Insects that reprogram host plants during colonization remind us that the insect side of plant-insect story is just as interesting as the plant side. Insect effectors secreted by the salivary glands play an important role in plant reprogramming. Recent discoveries point to large numbers of salivary effectors being produced by a single herbivore species. Since genetic and functional characterization of effectors is an arduous task, narrowing the field of candidates is useful. We present ideas about types and functions of effectors from research on blood-feeding parasites and their mammalian hosts. Because of their importance for human health, blood-feeding parasites have more tools from genomics and other - omics than plant-feeding parasites. Four themes have emerged: (1) mechanical damage resulting from attack by blood-feeding parasites triggers "early danger signals" in mammalian hosts, which are mediated by eATP, calcium, and hydrogen peroxide, (2) mammalian hosts need to modulate their immune responses to the three "early danger signals" and use apyrases, calreticulins, and peroxiredoxins, respectively, to achieve this, (3) blood-feeding parasites, like their mammalian hosts, rely on some of the same "early danger signals" and modulate their immune responses using the same proteins, and (4) blood-feeding parasites deploy apyrases, calreticulins, and peroxiredoxins in their saliva to manipulate the "danger signals" of their mammalian hosts. We review emerging evidence that plant-feeding insects also interfere with "early danger signals" of their hosts by deploying apyrases, calreticulins and peroxiredoxins in saliva. Given emerging links between these molecules, and plant growth and defense, we propose that these effectors interfere with phytohormone signaling, and therefore have a special importance for gall-inducing and leaf-mining insects, which manipulate host-plants to create better food and shelter. Copyright © 2015 Elsevier Ltd. All rights reserved.

Updated population metadata for United States historical climatology network stations

USGS Publications Warehouse

Owen, T.W.; Gallo, K.P.

2000-01-01

The United States Historical Climatology Network (HCN) serial temperature dataset is comprised of 1221 high-quality, long-term climate observing stations. The HCN dataset is available in several versions, one of which includes population-based temperature modifications to adjust urban temperatures for the "heat-island" effect. Unfortunately, the decennial population metadata file is not complete as missing values are present for 17.6% of the 12 210 population values associated with the 1221 individual stations during the 1900-90 interval. Retrospective grid-based populations. Within a fixed distance of an HCN station, were estimated through the use of a gridded population density dataset and historically available U.S. Census county data. The grid-based populations for the HCN stations provide values derived from a consistent methodology compared to the current HCN populations that can vary as definitions of the area associated with a city change over time. The use of grid-based populations may minimally be appropriate to augment populations for HCN climate stations that lack any population data, and are recommended when consistent and complete population data are required. The recommended urban temperature adjustments based on the HCN and grid-based methods of estimating station population can be significantly different for individual stations within the HCN dataset.

Are Tree Species Diversity and Genotypic Diversity Effects on Insect Herbivores Mediated by Ants?

PubMed Central

Campos-Navarrete, María José; Abdala-Roberts, Luis; Munguía-Rosas, Miguel A.; Parra-Tabla, Víctor

2015-01-01

Plant diversity can influence predators and omnivores and such effects may in turn influence herbivores and plants. However, evidence for these ecological feedbacks is rare. We evaluated if the effects of tree species (SD) and genotypic diversity (GD) on the abundance of different guilds of insect herbivores associated with big-leaf mahogany (Swietenia macrophylla) were contingent upon the protective effects of ants tending extra-floral nectaries of this species. This study was conducted within a larger experiment consisting of mahogany monocultures and species polycultures of four species and –within each of these two plot types– mahogany was represented by either one or four maternal families. We selected 24 plots spanning these treatment combinations, 10 mahogany plants/plot, and within each plot experimentally reduced ant abundance on half of the selected plants, and surveyed ant and herbivore abundance. There were positive effects of SD on generalist leaf-chewers and sap-feeders, but for the latter group this effect depended on the ant reduction treatment: SD positively influenced sap-feeders under ambient ant abundance but had no effect when ant abundance was reduced; at the same time, ants had negative effects on sap feeders in monoculture but no effect in polyculture. In contrast, SD did not influence specialist stem-borers or leaf-miners and this effect was not contingent upon ant reduction. Finally, GD did not influence any of the herbivore guilds studied, and such effects did not depend on the ant treatment. Overall, we show that tree species diversity influenced interactions between a focal plant species (mahogany) and ants, and that such effects in turn mediated plant diversity effects on some (sap-feeders) but not all the herbivores guilds studied. Our results suggest that the observed patterns are dependent on the combined effects of herbivore identity, diet breadth, and the source of plant diversity. PMID:26241962

Locating helicopter emergency medical service bases to optimise population coverage versus average response time.

PubMed

Garner, Alan A; van den Berg, Pieter L

2017-10-16

New South Wales (NSW), Australia has a network of multirole retrieval physician staffed helicopter emergency medical services (HEMS) with seven bases servicing a jurisdiction with population concentrated along the eastern seaboard. The aim of this study was to estimate optimal HEMS base locations within NSW using advanced mathematical modelling techniques. We used high resolution census population data for NSW from 2011 which divides the state into areas containing 200-800 people. Optimal HEMS base locations were estimated using the maximal covering location problem facility location optimization model and the average response time model, exploring the number of bases needed to cover various fractions of the population for a 45 min response time threshold or minimizing the overall average response time to all persons, both in green field scenarios and conditioning on the current base structure. We also developed a hybrid mathematical model where average response time was optimised based on minimum population coverage thresholds. Seven bases could cover 98% of the population within 45mins when optimised for coverage or reach the entire population of the state within an average of 21mins if optimised for response time. Given the existing bases, adding two bases could either increase the 45 min coverage from 91% to 97% or decrease the average response time from 21mins to 19mins. Adding a single specialist prehospital rapid response HEMS to the area of greatest population concentration decreased the average state wide response time by 4mins. The optimum seven base hybrid model that was able to cover 97.75% of the population within 45mins, and all of the population in an average response time of 18 mins included the rapid response HEMS model. HEMS base locations can be optimised based on either percentage of the population covered, or average response time to the entire population. We have also demonstrated a hybrid technique that optimizes response time for a given number of bases and minimum defined threshold of population coverage. Addition of specialized rapid response HEMS services to a system of multirole retrieval HEMS may reduce overall average response times by improving access in large urban areas.

Use of Mobile Device Data To Better Estimate Dynamic Population Size for Wastewater-Based Epidemiology.

PubMed

Thomas, Kevin V; Amador, Arturo; Baz-Lomba, Jose Antonio; Reid, Malcolm

2017-10-03

Wastewater-based epidemiology is an established approach for quantifying community drug use and has recently been applied to estimate population exposure to contaminants such as pesticides and phthalate plasticizers. A major source of uncertainty in the population weighted biomarker loads generated is related to estimating the number of people present in a sewer catchment at the time of sample collection. Here, the population quantified from mobile device-based population activity patterns was used to provide dynamic population normalized loads of illicit drugs and pharmaceuticals during a known period of high net fluctuation in the catchment population. Mobile device-based population activity patterns have for the first time quantified the high degree of intraday, week, and month variability within a specific sewer catchment. Dynamic population normalization showed that per capita pharmaceutical use remained unchanged during the period when static normalization would have indicated an average reduction of up to 31%. Per capita illicit drug use increased significantly during the monitoring period, an observation that was only possible to measure using dynamic population normalization. The study quantitatively confirms previous assessments that population estimates can account for uncertainties of up to 55% in static normalized data. Mobile device-based population activity patterns allow for dynamic normalization that yields much improved temporal and spatial trend analysis.

[Genetic differentiation of Isaria farinosa populations in Anhui Province of East China].

PubMed

Sun, Zhao-Hong; Luan, Feng-Gang; Zhang, Da-Min; Chen, Ming-Jun; Wang, Bin; Li, Zeng-Zhi

2011-11-01

Isaria farinosa is an important entomopathogenic fungus. By using ISSR, this paper studied the genetic heterogeneity of six I. farinosa populations at different localities of Anhui Province, East China. A total of 98.5% polymorphic loci were amplified with ten polymorphic primers, but the polymorphism at population level varied greatly, within the range of 59.6%-93.2%. The genetic differentiation index (G(st)) between the populations based on Nei's genetic heterogenesis analysis was 0.3365, and the gene flow (N(m)) was 0.4931. The genetic differentiation between the populations was lower than that within the populations, suggesting that the genetic variation of I. farinosa mainly come from the interior of the populations. The UPGMA clustering based on the genetic similarities between the isolates revealed that the Xishan population was monophylectic, while the other five populations were polyphylectic, with the Yaoluoping population being the most heterogenic and the Langyashan population being the least heterogenic. No correlations were observed between the geographic distance and the genetic distance of the populations. According to the UPGMA clustering based on the genetic distance between the populations, the six populations were classified into three groups, and this classification was accorded with the clustering based on geographic environment, suggesting the effects of environmental heterogeneity on the population heterogeneity.

Comparing population and incident data for optimal air ambulance base locations in Norway.

PubMed

Røislien, Jo; van den Berg, Pieter L; Lindner, Thomas; Zakariassen, Erik; Uleberg, Oddvar; Aardal, Karen; van Essen, J Theresia

2018-05-24

Helicopter emergency medical services are important in many health care systems. Norway has a nationwide physician manned air ambulance service servicing a country with large geographical variations in population density and incident frequencies. The aim of the study was to compare optimal air ambulance base locations using both population and incident data. We used municipality population and incident data for Norway from 2015. The 428 municipalities had a median (5-95 percentile) of 4675 (940-36,264) inhabitants and 10 (2-38) incidents. Optimal helicopter base locations were estimated using the Maximal Covering Location Problem (MCLP) optimization model, exploring the number and location of bases needed to cover various fractions of the population for time thresholds 30 and 45 min, in green field scenarios and conditioned on the existing base structure. The existing bases covered 96.90% of the population and 91.86% of the incidents for time threshold 45 min. Correlation between municipality population and incident frequencies was -0.0027, and optimal base locations varied markedly between the two data types, particularly when lowering the target time. The optimal solution using population density data put focus on the greater Oslo area, where one third of Norwegians live, while using incident data put focus on low population high incident areas, such as northern Norway and winter sport resorts. Using population density data as a proxy for incident frequency is not recommended, as the two data types lead to different optimal base locations. Lowering the target time increases the sensitivity to choice of data.

Making It Count: Improving Estimates of the Size of Transgender and Gender Nonconforming Populations.

PubMed

Deutsch, Madeline B

2016-06-01

An accurate estimate of the number of transgender and gender nonconforming people is essential to inform policy and funding priorities and decisions. Historical reports of population sizes of 1 in 4000 to 1 in 50,000 have been based on clinical populations and likely underestimate the size of the transgender population. More recent population-based studies have found a 10- to 100-fold increase in population size. Studies that estimate population size should be population based, employ the two-step method to allow for collection of both gender identity and sex assigned at birth, and include measures to capture the range of transgender people with nonbinary gender identities.

Cost-effectiveness of Population Screening for BRCA Mutations in Ashkenazi Jewish Women Compared With Family History–Based Testing

PubMed Central

Manchanda, Ranjit; Legood, Rosa; Burnell, Matthew; McGuire, Alistair; Raikou, Maria; Loggenberg, Kelly; Wardle, Jane; Sanderson, Saskia; Gessler, Sue; Side, Lucy; Balogun, Nyala; Desai, Rakshit; Kumar, Ajith; Dorkins, Huw; Wallis, Yvonne; Chapman, Cyril; Taylor, Rohan; Jacobs, Chris; Tomlinson, Ian; Beller, Uziel; Menon, Usha

2015-01-01

Background: Population-based testing for BRCA1/2 mutations detects the high proportion of carriers not identified by cancer family history (FH)–based testing. We compared the cost-effectiveness of population-based BRCA testing with the standard FH-based approach in Ashkenazi Jewish (AJ) women. Methods: A decision-analytic model was developed to compare lifetime costs and effects amongst AJ women in the UK of BRCA founder-mutation testing amongst: 1) all women in the population age 30 years or older and 2) just those with a strong FH (≥10% mutation risk). The model assumes that BRCA carriers are offered risk-reducing salpingo-oophorectomy and annual MRI/mammography screening or risk-reducing mastectomy. Model probabilities utilize the Genetic Cancer Prediction through Population Screening trial/published literature to estimate total costs, effects in terms of quality-adjusted life-years (QALYs), cancer incidence, incremental cost-effectiveness ratio (ICER), and population impact. Costs are reported at 2010 prices. Costs/outcomes were discounted at 3.5%. We used deterministic/probabilistic sensitivity analysis (PSA) to evaluate model uncertainty. Results: Compared with FH-based testing, population-screening saved 0.090 more life-years and 0.101 more QALYs resulting in 33 days’ gain in life expectancy. Population screening was found to be cost saving with a baseline-discounted ICER of -£2079/QALY. Population-based screening lowered ovarian and breast cancer incidence by 0.34% and 0.62%. Assuming 71% testing uptake, this leads to 276 fewer ovarian and 508 fewer breast cancer cases. Overall, reduction in treatment costs led to a discounted cost savings of £3.7 million. Deterministic sensitivity analysis and 94% of simulations on PSA (threshold £20000) indicated that population screening is cost-effective, compared with current NHS policy. Conclusion: Population-based screening for BRCA mutations is highly cost-effective compared with an FH-based approach in AJ women age 30 years and older. PMID:25435542

Assessing population exposure for landslide risk analysis using dasymetric cartography

NASA Astrophysics Data System (ADS)

Garcia, Ricardo A. C.; Oliveira, Sergio C.; Zezere, Jose L.

2015-04-01

Exposed Population is a major topic that needs to be taken into account in a full landslide risk analysis. Usually, risk analysis is based on an accounting of inhabitants number or inhabitants density, applied over statistical or administrative terrain units, such as NUTS or parishes. However, this kind of approach may skew the obtained results underestimating the importance of population, mainly in territorial units with predominance of rural occupation. Furthermore, the landslide susceptibility scores calculated for each terrain unit are frequently more detailed and accurate than the location of the exposed population inside each territorial unit based on Census data. These drawbacks are not the ideal setting when landslide risk analysis is performed for urban management and emergency planning. Dasymetric cartography, which uses a parameter or set of parameters to restrict the spatial distribution of a particular phenomenon, is a methodology that may help to enhance the resolution of Census data and therefore to give a more realistic representation of the population distribution. Therefore, this work aims to map and to compare the population distribution based on a traditional approach (population per administrative terrain units) and based on dasymetric cartography (population by building). The study is developed in the Region North of Lisbon using 2011 population data and following three main steps: i) the landslide susceptibility assessment based on statistical models independently validated; ii) the evaluation of population distribution (absolute and density) for different administrative territorial units (Parishes and BGRI - the basic statistical unit in the Portuguese Census); and iii) the dasymetric population's cartography based on building areal weighting. Preliminary results show that in sparsely populated administrative units, population density differs more than two times depending on the application of the traditional approach or the dasymetric cartography. This work was supported by the FCT - Portuguese Foundation for Science and Technology.

Consequences of population topology for studying gene flow using link-based landscape genetic methods.

PubMed

van Strien, Maarten J

2017-07-01

Many landscape genetic studies aim to determine the effect of landscape on gene flow between populations. These studies frequently employ link-based methods that relate pairwise measures of historical gene flow to measures of the landscape and the geographical distance between populations. However, apart from landscape and distance, there is a third important factor that can influence historical gene flow, that is, population topology (i.e., the arrangement of populations throughout a landscape). As the population topology is determined in part by the landscape configuration, I argue that it should play a more prominent role in landscape genetics. Making use of existing literature and theoretical examples, I discuss how population topology can influence results in landscape genetic studies and how it can be taken into account to improve the accuracy of these results. In support of my arguments, I have performed a literature review of landscape genetic studies published during the first half of 2015 as well as several computer simulations of gene flow between populations. First, I argue why one should carefully consider which population pairs should be included in link-based analyses. Second, I discuss several ways in which the population topology can be incorporated in response and explanatory variables. Third, I outline why it is important to sample populations in such a way that a good representation of the population topology is obtained. Fourth, I discuss how statistical testing for link-based approaches could be influenced by the population topology. I conclude the article with six recommendations geared toward better incorporating population topology in link-based landscape genetic studies.

Ancestral Relationships Using Metafounders: Finite Ancestral Populations and Across Population Relationships

PubMed Central

Legarra, Andres; Christensen, Ole F.; Vitezica, Zulma G.; Aguilar, Ignacio; Misztal, Ignacy

2015-01-01

Recent use of genomic (marker-based) relationships shows that relationships exist within and across base population (breeds or lines). However, current treatment of pedigree relationships is unable to consider relationships within or across base populations, although such relationships must exist due to finite size of the ancestral population and connections between populations. This complicates the conciliation of both approaches and, in particular, combining pedigree with genomic relationships. We present a coherent theoretical framework to consider base population in pedigree relationships. We suggest a conceptual framework that considers each ancestral population as a finite-sized pool of gametes. This generates across-individual relationships and contrasts with the classical view which each population is considered as an infinite, unrelated pool. Several ancestral populations may be connected and therefore related. Each ancestral population can be represented as a “metafounder,” a pseudo-individual included as founder of the pedigree and similar to an “unknown parent group.” Metafounders have self- and across relationships according to a set of parameters, which measure ancestral relationships, i.e., homozygozities within populations and relationships across populations. These parameters can be estimated from existing pedigree and marker genotypes using maximum likelihood or a method based on summary statistics, for arbitrarily complex pedigrees. Equivalences of genetic variance and variance components between the classical and this new parameterization are shown. Segregation variance on crosses of populations is modeled. Efficient algorithms for computation of relationship matrices, their inverses, and inbreeding coefficients are presented. Use of metafounders leads to compatibility of genomic and pedigree relationship matrices and to simple computing algorithms. Examples and code are given. PMID:25873631

Population-based programs for increasing colorectal cancer screening in the United States.

PubMed

Verma, Manisha; Sarfaty, Mona; Brooks, Durado; Wender, Richard C

2015-01-01

Answer questions and earn CME/CNE Screening to detect polyps or cancer at an early stage has been shown to produce better outcomes in colorectal cancer (CRC). Programs with a population-based approach can reach a large majority of the eligible population and can offer cost-effective interventions with the potential benefit of maximizing early cancer detection and prevention using a complete follow-up plan. The purpose of this review was to summarize the key features of population-based programs to increase CRC screening in the United States. A search was conducted in the SCOPUS, OvidSP, and PubMed databases. The authors selected published reports of population-based programs that met at least 5 of the 6 International Agency for Research on Cancer (IARC) criteria for cancer prevention and were known to the National Colorectal Cancer Roundtable. Interventions at the level of individual practices were not included in this review. IARC cancer prevention criteria served as a framework to assess the effective processes and elements of a population-based program. Eight programs were included in this review. Half of the programs met all IARC criteria, and all programs led to improvements in screening rates. The rate of colonoscopy after a positive stool test was heterogeneous among programs. Different population-based strategies were used to promote these screening programs, including system-based, provider-based, patient-based, and media-based strategies. Treatment of identified cancer cases was not included explicitly in 4 programs but was offered through routine medical care. Evidence-based methods for promoting CRC screening at a population level can guide the development of future approaches in health care prevention. The key elements of a successful population-based approach include adherence to the 6 IARC criteria and 4 additional elements (an identified external funding source, a structured policy for positive fecal occult blood test results and confirmed cancer cases, outreach activities for recruitment and patient education, and an established rescreening process). © 2015 American Cancer Society.

POPULATION AT RISK TO VARIOUS AIR POLLUTION EXPOSURES: DATA BASE 'POPATRISK'

EPA Science Inventory

The work reported was undertaken to provide the EPA with a user-oriented data base containing recent county-based information, for all counties in the contiguous United States, on population demographics, population mobility, climatology, emissions, air quality, and age-adjusted ...

Multi-population Genomic Relationships for Estimating Current Genetic Variances Within and Genetic Correlations Between Populations.

PubMed

Wientjes, Yvonne C J; Bijma, Piter; Vandenplas, Jérémie; Calus, Mario P L

2017-10-01

Different methods are available to calculate multi-population genomic relationship matrices. Since those matrices differ in base population, it is anticipated that the method used to calculate genomic relationships affects the estimate of genetic variances, covariances, and correlations. The aim of this article is to define the multi-population genomic relationship matrix to estimate current genetic variances within and genetic correlations between populations. The genomic relationship matrix containing two populations consists of four blocks, one block for population 1, one block for population 2, and two blocks for relationships between the populations. It is known, based on literature, that by using current allele frequencies to calculate genomic relationships within a population, current genetic variances are estimated. In this article, we theoretically derived the properties of the genomic relationship matrix to estimate genetic correlations between populations and validated it using simulations. When the scaling factor of across-population genomic relationships is equal to the product of the square roots of the scaling factors for within-population genomic relationships, the genetic correlation is estimated unbiasedly even though estimated genetic variances do not necessarily refer to the current population. When this property is not met, the correlation based on estimated variances should be multiplied by a correction factor based on the scaling factors. In this study, we present a genomic relationship matrix which directly estimates current genetic variances as well as genetic correlations between populations. Copyright © 2017 by the Genetics Society of America.

Cost effectiveness of population based BRCA1 founder mutation testing in Sephardi Jewish women.

PubMed

Patel, Shreeya; Legood, Rosa; Evans, D Gareth; Turnbull, Clare; Antoniou, Antonis C; Menon, Usha; Jacobs, Ian; Manchanda, Ranjit

2018-04-01

Population-based BRCA1/BRCA2 founder-mutation testing has been demonstrated as cost effective compared with family history based testing in Ashkenazi Jewish women. However, only 1 of the 3 Ashkenazi Jewish BRCA1/BRCA2 founder mutations (185delAG[c.68_69delAG]), 5382insC[c.5266dupC]), and 6174delT[c.5946delT]) is found in the Sephardi Jewish population (185delAG[c.68_69delAG]), and the overall prevalence of BRCA mutations in the Sephardi Jewish population is accordingly lower (0.7% compared with 2.5% in the Ashkenazi Jewish population). Cost-effectiveness analyses of BRCA testing have not previously been performed at these lower BRCA prevalence levels seen in the Sephardi Jewish population. Here we present a cost-effectiveness analysis for UK and US populations comparing population testing with clinical criteria/family history-based testing in Sephardi Jewish women. A Markov model was built comparing the lifetime costs and effects of population-based BRCA1 testing, with testing using family history-based clinical criteria in Sephardi Jewish women aged ≥30 years. BRCA1 carriers identified were offered magnetic resonance imaging/mammograms and risk-reducing surgery. Costs are reported at 2015 prices. Outcomes include breast cancer, ovarian cancer, and excess deaths from heart disease. All costs and outcomes are discounted at 3.5%. The time horizon is lifetime, and perspective is payer. The incremental cost-effectiveness ratio per quality-adjusted life-year was calculated. Parameter uncertainty was evaluated through 1-way and probabilistic sensitivity analysis. Population testing resulted in gain in life expectancy of 12 months (quality-adjusted life-year = 1.00). The baseline discounted incremental cost-effectiveness ratio for UK population-based testing was £67.04/quality-adjusted life-year and for US population was $308.42/quality-adjusted life-year. Results were robust in the 1-way sensitivity analysis. The probabilistic sensitivity analysis showed 100% of simulations were cost effective at £20,000/quality-adjusted life-year UK and the $100,000/quality-adjusted life-year US willingness-to-pay thresholds. Scenario analysis showed that population testing remains cost effective in UK and US populations, even if premenopausal oophorectomy does not reduce breast cancer risk or if hormone replacement therapy compliance is nil. Population-based BRCA1 testing is highly cost effective compared with clinical criteria-driven approach in Sephardi Jewish women. This supports changing the paradigm to population-based BRCA testing in the Jewish population, regardless of Ashkenazi/Sephardi ancestry. Copyright © 2017 Elsevier Inc. All rights reserved.

Ancestral Relationships Using Metafounders: Finite Ancestral Populations and Across Population Relationships.

PubMed

Legarra, Andres; Christensen, Ole F; Vitezica, Zulma G; Aguilar, Ignacio; Misztal, Ignacy

2015-06-01

Recent use of genomic (marker-based) relationships shows that relationships exist within and across base population (breeds or lines). However, current treatment of pedigree relationships is unable to consider relationships within or across base populations, although such relationships must exist due to finite size of the ancestral population and connections between populations. This complicates the conciliation of both approaches and, in particular, combining pedigree with genomic relationships. We present a coherent theoretical framework to consider base population in pedigree relationships. We suggest a conceptual framework that considers each ancestral population as a finite-sized pool of gametes. This generates across-individual relationships and contrasts with the classical view which each population is considered as an infinite, unrelated pool. Several ancestral populations may be connected and therefore related. Each ancestral population can be represented as a "metafounder," a pseudo-individual included as founder of the pedigree and similar to an "unknown parent group." Metafounders have self- and across relationships according to a set of parameters, which measure ancestral relationships, i.e., homozygozities within populations and relationships across populations. These parameters can be estimated from existing pedigree and marker genotypes using maximum likelihood or a method based on summary statistics, for arbitrarily complex pedigrees. Equivalences of genetic variance and variance components between the classical and this new parameterization are shown. Segregation variance on crosses of populations is modeled. Efficient algorithms for computation of relationship matrices, their inverses, and inbreeding coefficients are presented. Use of metafounders leads to compatibility of genomic and pedigree relationship matrices and to simple computing algorithms. Examples and code are given. Copyright © 2015 by the Genetics Society of America.

Population Education: A Knowledge Base.

ERIC Educational Resources Information Center

Jacobson, Willard J.

To aid junior high and high school educators and curriculum planners as they develop population education programs, the book provides an overview of the population education knowledge base. In addition, it suggests learning activities, discussion questions, and background information which can be integrated into courses dealing with population,…

Modelling Risk to US Military Populations from Stopping Blanket Mandatory Polio Vaccination.

PubMed

Burgess, Colleen; Burgess, Andrew; McMullen, Kellie

2017-01-01

Transmission of polio poses a threat to military forces when deploying to regions where such viruses are endemic. US-born soldiers generally enter service with immunity resulting from childhood immunization against polio; moreover, new recruits are routinely vaccinated with inactivated poliovirus vaccine (IPV), supplemented based upon deployment circumstances. Given residual protection from childhood vaccination, risk-based vaccination may sufficiently protect troops from polio transmission. This analysis employed a mathematical system for polio transmission within military populations interacting with locals in a polio-endemic region to evaluate changes in vaccination policy. Removal of blanket immunization had no effect on simulated polio incidence among deployed military populations when risk-based immunization was employed; however, when these individuals reintegrated with their base populations, risk of transmission to nondeployed personnel increased by 19%. In the absence of both blanket- and risk-based immunization, transmission to nondeployed populations increased by 25%. The overall number of new infections among nondeployed populations was negligible for both scenarios due to high childhood immunization rates, partial protection against transmission conferred by IPV, and low global disease incidence levels. Risk-based immunization driven by deployment to polio-endemic regions is sufficient to prevent transmission among both deployed and nondeployed US military populations.

Prostate-Specific Antigen (PSA)–Based Population Screening for Prostate Cancer: An Economic Analysis

PubMed Central

Tawfik, A

2015-01-01

Background The prostate-specific antigen (PSA) blood test has become widely used in Canada to test for prostate cancer (PC), the most common cancer among Canadian men. Data suggest that population-based PSA screening may not improve overall survival. Objectives This analysis aimed to review existing economic evaluations of population-based PSA screening, determine current spending on opportunistic PSA screening in Ontario, and estimate the cost of introducing a population-based PSA screening program in the province. Methods A systematic literature search was performed to identify economic evaluations of population-based PSA screening strategies published from 1998 to 2013. Studies were assessed for their methodological quality and applicability to the Ontario setting. An original cost analysis was also performed, using data from Ontario administrative sources and from the published literature. One-year costs were estimated for 4 strategies: no screening, current (opportunistic) screening of men aged 40 years and older, current (opportunistic) screening of men aged 50 to 74 years, and population-based screening of men aged 50 to 74 years. The analysis was conducted from the payer perspective. Results The literature review demonstrated that, overall, population-based PSA screening is costly and cost-ineffective but may be cost-effective in specific populations. Only 1 Canadian study, published 15 years ago, was identified. Approximately $119.2 million is being spent annually on PSA screening of men aged 40 years and older in Ontario, including close to $22 million to screen men younger than 50 and older than 74 years of age (i.e., outside the target age range for a population-based program). A population-based screening program in Ontario would cost approximately $149.4 million in the first year. Limitations Estimates were based on the synthesis of data from a variety of sources, requiring several assumptions and causing uncertainty in the results. For example, where Ontario-specific data were unavailable, data from the United States were used. Conclusions PSA screening is associated with significant costs to the health care system when the cost of the PSA test itself is considered in addition to the costs of diagnosis, staging, and treatment of screen-detected PCs. PMID:26366237

Optimizing the creation of base populations for aquaculture breeding programs using phenotypic and genomic data and its consequences on genetic progress.

PubMed

Fernández, Jesús; Toro, Miguel Á; Sonesson, Anna K; Villanueva, Beatriz

2014-01-01

The success of an aquaculture breeding program critically depends on the way in which the base population of breeders is constructed since all the genetic variability for the traits included originally in the breeding goal as well as those to be included in the future is contained in the initial founders. Traditionally, base populations were created from a number of wild strains by sampling equal numbers from each strain. However, for some aquaculture species improved strains are already available and, therefore, mean phenotypic values for economically important traits can be used as a criterion to optimize the sampling when creating base populations. Also, the increasing availability of genome-wide genotype information in aquaculture species could help to refine the estimation of relationships within and between candidate strains and, thus, to optimize the percentage of individuals to be sampled from each strain. This study explores the advantages of using phenotypic and genome-wide information when constructing base populations for aquaculture breeding programs in terms of initial and subsequent trait performance and genetic diversity level. Results show that a compromise solution between diversity and performance can be found when creating base populations. Up to 6% higher levels of phenotypic performance can be achieved at the same level of global diversity in the base population by optimizing the selection of breeders instead of sampling equal numbers from each strain. The higher performance observed in the base population persisted during 10 generations of phenotypic selection applied in the subsequent breeding program.

Evaluating Nicotine Replacement Therapy and Stage-Based Therapies in a Population-Based Effectiveness Trial

ERIC Educational Resources Information Center

Velicer, Wayne F.; Friedman, Robert H.; Fava, Joseph L.; Gulliver, Suzy B.; Keller, Stefan; Sun, Xiaowu; Ramelson, Harley; Prochaska, James O.

2006-01-01

Pharmacological interventions for smoking cessation are typically evaluated using volunteer samples (efficacy trials) but should also be evaluated in population-based trials (effectiveness trials). Nicotine replacement therapy (NRT) alone and in combination with behavioral interventions was evaluated on a population of smokers from a New England…

Combination of graph heuristics in producing initial solution of curriculum based course timetabling problem

NASA Astrophysics Data System (ADS)

Wahid, Juliana; Hussin, Naimah Mohd

2016-08-01

The construction of population of initial solution is a crucial task in population-based metaheuristic approach for solving curriculum-based university course timetabling problem because it can affect the convergence speed and also the quality of the final solution. This paper presents an exploration on combination of graph heuristics in construction approach in curriculum based course timetabling problem to produce a population of initial solutions. The graph heuristics were set as single and combination of two heuristics. In addition, several ways of assigning courses into room and timeslot are implemented. All settings of heuristics are then tested on the same curriculum based course timetabling problem instances and are compared with each other in terms of number of population produced. The result shows that combination of saturation degree followed by largest degree heuristic produce the highest number of population of initial solutions. The results from this study can be used in the improvement phase of algorithm that uses population of initial solutions.

CDPOP: A spatially explicit cost distance population genetics program

Treesearch

Erin L. Landguth; S. A. Cushman

2010-01-01

Spatially explicit simulation of gene flow in complex landscapes is essential to explain observed population responses and provide a foundation for landscape genetics. To address this need, we wrote a spatially explicit, individual-based population genetics model (CDPOP). The model implements individual-based population modelling with Mendelian inheritance and k-allele...

Landscape-based population viability models demonstrate importance of strategic conservation planning for birds

Treesearch

Thomas W. Bonnot; Frank R. Thompson; Joshua J. Millspaugh; D. Todd Jones-Farland

2013-01-01

Efforts to conserve regional biodiversity in the face of global climate change, habitat loss and fragmentation will depend on approaches that consider population processes at multiple scales. By combining habitat and demographic modeling, landscape-based population viability models effectively relate small-scale habitat and landscape patterns to regional population...

Methods for estimating population density in data-limited areas: evaluating regression and tree-based models in Peru.

PubMed

Anderson, Weston; Guikema, Seth; Zaitchik, Ben; Pan, William

2014-01-01

Obtaining accurate small area estimates of population is essential for policy and health planning but is often difficult in countries with limited data. In lieu of available population data, small area estimate models draw information from previous time periods or from similar areas. This study focuses on model-based methods for estimating population when no direct samples are available in the area of interest. To explore the efficacy of tree-based models for estimating population density, we compare six different model structures including Random Forest and Bayesian Additive Regression Trees. Results demonstrate that without information from prior time periods, non-parametric tree-based models produced more accurate predictions than did conventional regression methods. Improving estimates of population density in non-sampled areas is important for regions with incomplete census data and has implications for economic, health and development policies.

Methods for Estimating Population Density in Data-Limited Areas: Evaluating Regression and Tree-Based Models in Peru

PubMed Central

Anderson, Weston; Guikema, Seth; Zaitchik, Ben; Pan, William

2014-01-01

Obtaining accurate small area estimates of population is essential for policy and health planning but is often difficult in countries with limited data. In lieu of available population data, small area estimate models draw information from previous time periods or from similar areas. This study focuses on model-based methods for estimating population when no direct samples are available in the area of interest. To explore the efficacy of tree-based models for estimating population density, we compare six different model structures including Random Forest and Bayesian Additive Regression Trees. Results demonstrate that without information from prior time periods, non-parametric tree-based models produced more accurate predictions than did conventional regression methods. Improving estimates of population density in non-sampled areas is important for regions with incomplete census data and has implications for economic, health and development policies. PMID:24992657

Modelling Risk to US Military Populations from Stopping Blanket Mandatory Polio Vaccination

PubMed Central

Burgess, Andrew

2017-01-01

Objectives Transmission of polio poses a threat to military forces when deploying to regions where such viruses are endemic. US-born soldiers generally enter service with immunity resulting from childhood immunization against polio; moreover, new recruits are routinely vaccinated with inactivated poliovirus vaccine (IPV), supplemented based upon deployment circumstances. Given residual protection from childhood vaccination, risk-based vaccination may sufficiently protect troops from polio transmission. Methods This analysis employed a mathematical system for polio transmission within military populations interacting with locals in a polio-endemic region to evaluate changes in vaccination policy. Results Removal of blanket immunization had no effect on simulated polio incidence among deployed military populations when risk-based immunization was employed; however, when these individuals reintegrated with their base populations, risk of transmission to nondeployed personnel increased by 19%. In the absence of both blanket- and risk-based immunization, transmission to nondeployed populations increased by 25%. The overall number of new infections among nondeployed populations was negligible for both scenarios due to high childhood immunization rates, partial protection against transmission conferred by IPV, and low global disease incidence levels. Conclusion Risk-based immunization driven by deployment to polio-endemic regions is sufficient to prevent transmission among both deployed and nondeployed US military populations. PMID:29104608

First experiences in the implementation of biometric technology to link data from Health and Demographic Surveillance Systems with health facility data.

PubMed

Serwaa-Bonsu, Adwoa; Herbst, Abraham J; Reniers, Georges; Ijaa, Wilfred; Clark, Benjamin; Kabudula, Chodziwadziwa; Sankoh, Osman

2010-02-24

In developing countries, Health and Demographic Surveillance Systems (HDSSs) provide a framework for tracking demographic and health dynamics over time in a defined geographical area. Many HDSSs co-exist with facility-based data sources in the form of Health Management Information Systems (HMIS). Integrating both data sources through reliable record linkage could provide both numerator and denominator populations to estimate disease prevalence and incidence rates in the population and enable determination of accurate health service coverage. To measure the acceptability and performance of fingerprint biometrics to identify individuals in demographic surveillance populations and those attending health care facilities serving the surveillance populations. Two HDSS sites used fingerprint biometrics for patient and/or surveillance population participant identification. The proportion of individuals for whom a fingerprint could be successfully enrolled were characterised in terms of age and sex. Adult (18-65 years) fingerprint enrolment rates varied between 94.1% (95% CI 93.6-94.5) for facility-based fingerprint data collection at the Africa Centre site to 96.7% (95% CI 95.9-97.6) for population-based fingerprint data collection at the Agincourt site. Fingerprint enrolment rates in children under 1 year old (Africa Centre site) were only 55.1% (95% CI 52.7-57.4). By age 5, child fingerprint enrolment rates were comparable to those of adults. This work demonstrates the feasibility of fingerprint-based individual identification for population-based research in developing countries. Record linkage between demographic surveillance population databases and health care facility data based on biometric identification systems would allow for a more comprehensive evaluation of population health, including the ability to study health service utilisation from a population perspective, rather than the more restrictive health service perspective.

Extension of landscape-based population viability models to ecoregional scales for conservation planning

Treesearch

Thomas W. Bonnot; Frank R. III Thompson; Joshua Millspaugh

2011-01-01

Landscape-based population models are potentially valuable tools in facilitating conservation planning and actions at large scales. However, such models have rarely been applied at ecoregional scales. We extended landscape-based population models to ecoregional scales for three species of concern in the Central Hardwoods Bird Conservation Region and compared model...

Extinction-effective population index: incorporating life-history variations in population viability analysis.

PubMed

Fujiwara, Masami

2007-09-01

Viability status of populations is a commonly used measure for decision-making in the management of populations. One of the challenges faced by managers is the need to consistently allocate management effort among populations. This allocation should in part be based on comparison of extinction risks among populations. Unfortunately, common criteria that use minimum viable population size or count-based population viability analysis (PVA) often do not provide results that are comparable among populations, primarily because they lack consistency in determining population size measures and threshold levels of population size (e.g., minimum viable population size and quasi-extinction threshold). Here I introduce a new index called the "extinction-effective population index," which accounts for differential effects of demographic stochasticity among organisms with different life-history strategies and among individuals in different life stages. This index is expected to become a new way of determining minimum viable population size criteria and also complement the count-based PVA. The index accounts for the difference in life-history strategies of organisms, which are modeled using matrix population models. The extinction-effective population index, sensitivity, and elasticity are demonstrated in three species of Pacific salmonids. The interpretation of the index is also provided by comparing them with existing demographic indices. Finally, a measure of life-history-specific effect of demographic stochasticity is derived.

Amniotic fluid embolism mortality rate.

PubMed

Benson, Michael D

2017-11-01

The objective of this study was to determine the mortality rate of amniotic fluid embolism (AFE) using population-based studies and case series. A literature search was conducted using the two key words: 'amniotic fluid embolism (AFE)' AND 'mortality rate'. Thirteen population-based studies were evaluated, as well as 36 case series including at least two patients. The mortality rate from population-based studies varied from 11% to 44%. When nine population-based studies with over 17 000 000 live births were aggregated, the maternal mortality rate was 20.4%. In contrast, the mortality rate of AFE in case series varies from 0% to 100% with numerous rates in between. The AFE mortality rate in population-based studies varied from 11% to 44% with the best available evidence supporting an overall mortality rate of 20.4%. Data from case series should no longer be used as a basis for describing the lethality of AFE. © 2017 Japan Society of Obstetrics and Gynecology.

An agent-based computational model for tuberculosis spreading on age-structured populations

NASA Astrophysics Data System (ADS)

Graciani Rodrigues, C. C.; Espíndola, Aquino L.; Penna, T. J. P.

2015-06-01

In this work we present an agent-based computational model to study the spreading of the tuberculosis (TB) disease on age-structured populations. The model proposed is a merge of two previous models: an agent-based computational model for the spreading of tuberculosis and a bit-string model for biological aging. The combination of TB with the population aging, reproduces the coexistence of health states, as seen in real populations. In addition, the universal exponential behavior of mortalities curves is still preserved. Finally, the population distribution as function of age shows the prevalence of TB mostly in elders, for high efficacy treatments.

Population structure of humpback whales in the western and central South Pacific Ocean as determined by vocal exchange among populations.

PubMed

Garland, Ellen C; Goldizen, Anne W; Lilley, Matthew S; Rekdahl, Melinda L; Garrigue, Claire; Constantine, Rochelle; Hauser, Nan Daeschler; Poole, M Michael; Robbins, Jooke; Noad, Michael J

2015-08-01

For cetaceans, population structure is traditionally determined by molecular genetics or photographically identified individuals. Acoustic data, however, has provided information on movement and population structure with less effort and cost than traditional methods in an array of taxa. Male humpback whales (Megaptera novaeangliae) produce a continually evolving vocal sexual display, or song, that is similar among all males in a population. The rapid cultural transmission (the transfer of information or behavior between conspecifics through social learning) of different versions of this display between distinct but interconnected populations in the western and central South Pacific region presents a unique way to investigate population structure based on the movement dynamics of a song (acoustic) display. Using 11 years of data, we investigated an acoustically based population structure for the region by comparing stereotyped song sequences among populations and years. We used the Levenshtein distance technique to group previously defined populations into (vocally based) clusters based on the overall similarity of their song display in space and time. We identified the following distinct vocal clusters: western cluster, 1 population off eastern Australia; central cluster, populations around New Caledonia, Tonga, and American Samoa; and eastern region, either a single cluster or 2 clusters, one around the Cook Islands and the other off French Polynesia. These results are consistent with the hypothesis that each breeding aggregation represents a distinct population (each occupied a single, terminal node) in a metapopulation, similar to the current understanding of population structure based on genetic and photo-identification studies. However, the central vocal cluster had higher levels of song-sharing among populations than the other clusters, indicating that levels of vocal connectivity varied within the region. Our results demonstrate the utility and value of using culturally transmitted vocal patterns as a way of defining connectivity to infer population structure. We suggest vocal patterns be incorporated by the International Whaling Commission in conjunction with traditional methods in the assessment of structure. © 2015, Society for Conservation Biology.

Distinct Roles of Jasmonates and Aldehydes in Plant-Defense Responses

PubMed Central

Chehab, E. Wassim; Kaspi, Roy; Savchenko, Tatyana; Rowe, Heather; Negre-Zakharov, Florence; Kliebenstein, Dan; Dehesh, Katayoon

2008-01-01

Background Many inducible plant-defense responses are activated by jasmonates (JAs), C6-aldehydes, and their corresponding derivatives, produced by the two main competing branches of the oxylipin pathway, the allene oxide synthase (AOS) and hydroperoxide lyase (HPL) branches, respectively. In addition to competition for substrates, these branch-pathway-derived metabolites have substantial overlap in regulation of gene expression. Past experiments to define the role of C6-aldehydes in plant defense responses were biased towards the exogenous application of the synthetic metabolites or the use of genetic manipulation of HPL expression levels in plant genotypes with intact ability to produce the competing AOS-derived metabolites. To uncouple the roles of the C6-aldehydes and jasmonates in mediating direct and indirect plant-defense responses, we generated Arabidopsis genotypes lacking either one or both of these metabolites. These genotypes were subsequently challenged with a phloem-feeding insect (aphids: Myzus persicae), an insect herbivore (leafminers: Liriomyza trifolii), and two different necrotrophic fungal pathogens (Botrytis cinerea and Alternaria brassicicola). We also characterized the volatiles emitted by these plants upon aphid infestation or mechanical wounding and identified hexenyl acetate as the predominant compound in these volatile blends. Subsequently, we examined the signaling role of this compound in attracting the parasitoid wasp (Aphidius colemani), a natural enemy of aphids. Principal Findings This study conclusively establishes that jasmonates and C6-aldehydes play distinct roles in plant defense responses. The jasmonates are indispensable metabolites in mediating the activation of direct plant-defense responses, whereas the C6-aldehyes are not. On the other hand, hexenyl acetate, an acetylated C6-aldehyde, is the predominant wound-inducible volatile signal that mediates indirect defense responses by directing tritrophic (plant-herbivore-natural enemy) interactions. Significance The data suggest that jasmonates and hexenyl acetate play distinct roles in mediating direct and indirect plant-defense responses. The potential advantage of this “division of labor” is to ensure the most effective defense strategy that minimizes incurred damages at a reduced metabolic cost. PMID:18382679

AN INDIVIDUAL-BASED MODEL OF COTTUS POPULATION DYNAMICS

EPA Science Inventory

We explored population dynamics of a southern Appalachian population of Cottus bairdi using a spatially-explicit, individual-based model. The model follows daily growth, mortality, and spawning of individuals as a function of flow and temperature. We modeled movement of juveniles...

Predictors of Cerebral Palsy in Very Preterm Infants: The EPIPAGE Prospective Population-Based Cohort Study

ERIC Educational Resources Information Center

Beaino, Ghada; Khoshnood, Babak; Kaminski, Monique; Pierrat, Veronique; Marret, Stephane; Matis, Jacqueline; Ledesert, Bernard; Thiriez, Gerard; Fresson, Jeanne; Roze, Jean-Christophe; Zupan-Simunek, Veronique; Arnaud, Catherine; Burguet, Antoine; Larroque, Beatrice; Breart, Gerard; Ancel, Pierre-Yves

2010-01-01

Aim: The aim of this study was to assess the independent role of cerebral lesions on ultrasound scan, and several other neonatal and obstetric factors, as potential predictors of cerebral palsy (CP) in a large population-based cohort of very preterm infants. Method: As part of EPIPAGE, a population-based prospective cohort study, perinatal data…

Reliability of confidence intervals calculated by bootstrap and classical methods using the FIA 1-ha plot design

Treesearch

H. T. Schreuder; M. S. Williams

2000-01-01

In simulation sampling from forest populations using sample sizes of 20, 40, and 60 plots respectively, confidence intervals based on the bootstrap (accelerated, percentile, and t-distribution based) were calculated and compared with those based on the classical t confidence intervals for mapped populations and subdomains within those populations. A 68.1 ha mapped...

Accuracy of Predicted Genomic Breeding Values in Purebred and Crossbred Pigs.

PubMed

Hidalgo, André M; Bastiaansen, John W M; Lopes, Marcos S; Harlizius, Barbara; Groenen, Martien A M; de Koning, Dirk-Jan

2015-05-26

Genomic selection has been widely implemented in dairy cattle breeding when the aim is to improve performance of purebred animals. In pigs, however, the final product is a crossbred animal. This may affect the efficiency of methods that are currently implemented for dairy cattle. Therefore, the objective of this study was to determine the accuracy of predicted breeding values in crossbred pigs using purebred genomic and phenotypic data. A second objective was to compare the predictive ability of SNPs when training is done in either single or multiple populations for four traits: age at first insemination (AFI); total number of piglets born (TNB); litter birth weight (LBW); and litter variation (LVR). We performed marker-based and pedigree-based predictions. Within-population predictions for the four traits ranged from 0.21 to 0.72. Multi-population prediction yielded accuracies ranging from 0.18 to 0.67. Predictions across purebred populations as well as predicting genetic merit of crossbreds from their purebred parental lines for AFI performed poorly (not significantly different from zero). In contrast, accuracies of across-population predictions and accuracies of purebred to crossbred predictions for LBW and LVR ranged from 0.08 to 0.31 and 0.11 to 0.31, respectively. Accuracy for TNB was zero for across-population prediction, whereas for purebred to crossbred prediction it ranged from 0.08 to 0.22. In general, marker-based outperformed pedigree-based prediction across populations and traits. However, in some cases pedigree-based prediction performed similarly or outperformed marker-based prediction. There was predictive ability when purebred populations were used to predict crossbred genetic merit using an additive model in the populations studied. AFI was the only exception, indicating that predictive ability depends largely on the genetic correlation between PB and CB performance, which was 0.31 for AFI. Multi-population prediction was no better than within-population prediction for the purebred validation set. Accuracy of prediction was very trait-dependent. Copyright © 2015 Hidalgo et al.

A hospital-based birth weight analysis using computerized perinatal data base for a Chinese population.

PubMed

Fu, Jing; Yu, Mei

2011-04-01

We aimed to construct birth weight-for-gestational age nomograms based on a computerized perinatal data base in a hospital-based Chinese population. Retrospectively collected 28,052 singleton deliveries at Women and Children's Medical Center, Guangzhou, China. Standard curves of birth weight from 27 to 43 week's gestation were computed. The nomograms included the 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles and standard deviations. 79.9% pregnant women delivered between 38, 39, and 40 gestational week, and the mean birth weights are 3160, 3282, and 3388 g, respectively. Preterm birth is 5.7%. In general, male birth weights are greater than females at each gestational week. The hospital-based Chinese population birth weight is lower than that of North American and Scandinavian population. A different standard birth weight is needed for different population. A hospital-based birth weight curve by gestational week is established, which can be a useful tool to estimate intrauterine fetal growth to define SGA or LGA fetuses.

Computing travel time when the exact address is unknown: a comparison of point and polygon ZIP code approximation methods.

PubMed

Berke, Ethan M; Shi, Xun

2009-04-29

Travel time is an important metric of geographic access to health care. We compared strategies of estimating travel times when only subject ZIP code data were available. Using simulated data from New Hampshire and Arizona, we estimated travel times to nearest cancer centers by using: 1) geometric centroid of ZIP code polygons as origins, 2) population centroids as origin, 3) service area rings around each cancer center, assigning subjects to rings by assuming they are evenly distributed within their ZIP code, 4) service area rings around each center, assuming the subjects follow the population distribution within the ZIP code. We used travel times based on street addresses as true values to validate estimates. Population-based methods have smaller errors than geometry-based methods. Within categories (geometry or population), centroid and service area methods have similar errors. Errors are smaller in urban areas than in rural areas. Population-based methods are superior to the geometry-based methods, with the population centroid method appearing to be the best choice for estimating travel time. Estimates in rural areas are less reliable.

Aligning population-based care management with chronic disease complexity.

PubMed

Hewner, Sharon; Seo, Jin Young; Gothard, Sandra E; Johnson, Barbara J

2014-01-01

Risk-stratified care management requires knowledge of the complexity of chronic disease and comorbidity, information that is often not readily available in the primary care setting. The purpose of this article was to describe a population-based approach to risk-stratified care management that could be applied in primary care. Three populations (Medicaid, Medicare, and privately insured) at a regional health plan were divided into risk-stratified cohorts based on chronic disease and complexity, and utilization was compared before and after the implementation of population-specific care management teams of nurses. Risk-stratified care management was associated with reductions in hospitalization rates in all three populations, but the opportunities to avoid admissions were different. Knowledge of population complexity is critical to the development of risk-stratified care management in primary care, and a complexity matrix can help nurses identify gaps in care and align interventions to cohort and population needs. Copyright © 2014 Elsevier Inc. All rights reserved.

Non-parametric estimation of population size changes from the site frequency spectrum.

PubMed

Waltoft, Berit Lindum; Hobolth, Asger

2018-06-11

Changes in population size is a useful quantity for understanding the evolutionary history of a species. Genetic variation within a species can be summarized by the site frequency spectrum (SFS). For a sample of size n, the SFS is a vector of length n - 1 where entry i is the number of sites where the mutant base appears i times and the ancestral base appears n - i times. We present a new method, CubSFS, for estimating the changes in population size of a panmictic population from an observed SFS. First, we provide a straightforward proof for the expression of the expected site frequency spectrum depending only on the population size. Our derivation is based on an eigenvalue decomposition of the instantaneous coalescent rate matrix. Second, we solve the inverse problem of determining the changes in population size from an observed SFS. Our solution is based on a cubic spline for the population size. The cubic spline is determined by minimizing the weighted average of two terms, namely (i) the goodness of fit to the observed SFS, and (ii) a penalty term based on the smoothness of the changes. The weight is determined by cross-validation. The new method is validated on simulated demographic histories and applied on unfolded and folded SFS from 26 different human populations from the 1000 Genomes Project.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kostova, T; Carlsen, T

We present a study, based on simulations with SERDYCA, a spatially-explicit individual based model of rodent dynamics, on the connection between population persistence and the presence of inhomogeneities in the habitat. We are specifically interested on the effect that inhomogeneities that do not fragment the environment, have on population persistence. Our results suggest that a certain percentage of inhomogeneities can increase the average time to extinction of the population. Inhomogeneities decrease the population density and can increase the ratio of juveniles in the population thus providing a better chance for the population to restore itself after a severe period withmore » critically low population density. We call this the ''inhomogeneity localization effect''.« less

Genetic differentiation among North Atlantic killer whale populations.

PubMed

Foote, Andrew D; Vilstrup, Julia T; De Stephanis, Renaud; Verborgh, Philippe; Abel Nielsen, Sandra C; Deaville, Robert; Kleivane, Lars; Martín, Vidal; Miller, Patrick J O; Oien, Nils; Pérez-Gil, Monica; Rasmussen, Morten; Reid, Robert J; Robertson, Kelly M; Rogan, Emer; Similä, Tiu; Tejedor, Maria L; Vester, Heike; Víkingsson, Gísli A; Willerslev, Eske; Gilbert, M Thomas P; Piertney, Stuart B

2011-02-01

Population genetic structure of North Atlantic killer whale samples was resolved from differences in allele frequencies of 17 microsatellite loci, mtDNA control region haplotype frequencies and for a subset of samples, using complete mitogenome sequences. Three significantly differentiated populations were identified. Differentiation based on microsatellite allele frequencies was greater between the two allopatric populations than between the two pairs of partially sympatric populations. Spatial clustering of individuals within each of these populations overlaps with the distribution of particular prey resources: herring, mackerel and tuna, which each population has been seen predating. Phylogenetic analyses using complete mitogenomes suggested two populations could have resulted from single founding events and subsequent matrilineal expansion. The third population, which was sampled at lower latitudes and lower density, consisted of maternal lineages from three highly divergent clades. Pairwise population differentiation was greater for estimates based on mtDNA control region haplotype frequencies than for estimates based on microsatellite allele frequencies, and there were no mitogenome haplotypes shared among populations. This suggests low or no female migration and that gene flow was primarily male mediated when populations spatially and temporally overlap. These results demonstrate that genetic differentiation can arise through resource specialization in the absence of physical barriers to gene flow. © 2010 Blackwell Publishing Ltd.

Predictors of Disordered Eating in Adolescence and Young Adulthood: A Population-Based, Longitudinal Study of Females and Males in Norway

ERIC Educational Resources Information Center

Abebe, Dawit Shawel; Torgersen, Leila; Lien, Lars; Hafstad, Gertrud S.; von Soest, Tilmann

2014-01-01

We investigated longitudinal predictors for disordered eating from early adolescence to young adulthood (12-34 years) across gender and different developmental phases among Norwegian young people. Survey data from a population-based sample were collected at four time points (T) over a 13-year time span. A population-based sample of 5,679 females…

POPULATION-BASED EXPOSURE MODELING FOR AIR POLLUTANTS AT EPA'S NATIONAL EXPOSURE RESEARCH LABORATORY

EPA Science Inventory

The US EPA's National Exposure Research Laboratory (NERL) has been developing, applying, and evaluating population-based exposure models to improve our understanding of the variability in personal exposure to air pollutants. Estimates of population variability are needed for E...

Feasibility of Population Health Analytics and Data Visualization for Decision Support in the Infectious Diseases Domain

PubMed Central

Del Fiol, Guilherme; Butler, Jorie; Livnat, Yarden; Mayer, Jeanmarie; Samore, Matthew; Jones, Makoto; Weir, Charlene

2016-01-01

Summary Objective Big data or population-based information has the potential to reduce uncertainty in medicine by informing clinicians about individual patient care. The objectives of this study were: 1) to explore the feasibility of extracting and displaying population-based information from an actual clinical population’s database records, 2) to explore specific design features for improving population display, 3) to explore perceptions of population information displays, and 4) to explore the impact of population information display on cognitive outcomes. Methods We used the Veteran’s Affairs (VA) database to identify similar complex patients based on a similar complex patient case. Study outcomes measures were 1) preferences for population information display 2) time looking at the population display, 3) time to read the chart, and 4) appropriateness of plans with pre- and post-presentation of population data. Finally, we redesigned the population information display based on our findings from this study. Results The qualitative data analysis for preferences of population information display resulted in four themes: 1) trusting the big/population data can be an issue, 2) embedded analytics is necessary to explore patient similarities, 3) need for tools to control the view (overview, zoom and filter), and 4) different presentations of the population display can be beneficial to improve the display. We found that appropriateness of plans was at 60% for both groups (t9=-1.9; p=0.08), and overall time looking at the population information display was 2.3 minutes versus 3.6 minutes with experts processing information faster than non-experts (t8= -2.3, p=0.04). Conclusion A population database has great potential for reducing complexity and uncertainty in medicine to improve clinical care. The preferences identified for the population information display will guide future health information technology system designers for better and more intuitive display. PMID:27437065

Neighborhood social capital is associated with participation in health checks of a general population: a multilevel analysis of a population-based lifestyle intervention- the Inter99 study.

PubMed

Bender, Anne Mette; Kawachi, Ichiro; Jørgensen, Torben; Pisinger, Charlotta

2015-07-22

Participation in population-based preventive health check has declined over the past decades. More research is needed to determine factors enhancing participation. The objective of this study was to examine the association between two measures of neighborhood level social capital on participation in the health check phase of a population-based lifestyle intervention. The study population comprised 12,568 residents of 73 Danish neighborhoods in the intervention group of a large population-based lifestyle intervention study - the Inter99. Two measures of social capital were applied; informal socializing and voting turnout. In a multilevel analysis only adjusting for age and sex, a higher level of neighborhood social capital was associated with higher probability of participating in the health check. Inclusion of both individual socioeconomic position and neighborhood deprivation in the model attenuated the coefficients for informal socializing, while voting turnout became non-significant. Higher level of neighborhood social capital was associated with higher probability of participating in the health check phase of a population-based lifestyle intervention. Most of the association between neighborhood social capital and participation in preventive health checks can be explained by differences in individual socioeconomic position and level of neighborhood deprivation. Nonetheless, there seems to be some residual association between social capital and health check participation, suggesting that activating social relations in the community may be an avenue for boosting participation rates in population-based health checks. ClinicalTrials.gov (registration no. NCT00289237 ).

Productivity losses in chronic obstructive pulmonary disease: a population-based survey.

PubMed

Erdal, Marta; Johannessen, Ane; Askildsen, Jan Erik; Eagan, Tomas; Gulsvik, Amund; Grønseth, Rune

2014-01-01

We aimed to estimate incremental productivity losses (sick leave and disability) of spirometry-defined chronic obstructive pulmonary disease (COPD) in a population-based sample and in hospital-recruited patients with COPD. Furthermore, we examined predictors of productivity losses by multivariate analyses. We performed four quarterly telephone interviews of 53 and 107 population-based patients with COPD and controls, as well as 102 hospital-recruited patients with COPD below retirement age. Information was gathered regarding annual productivity loss, exacerbations of respiratory symptoms and comorbidities. Incremental productivity losses were estimated by multivariate quantile median regression according to the human capital approach, adjusting for sex, age, smoking habits, education and lung function. Main effect variables were COPD/control status, number of comorbidities and exacerbations of respiratory symptoms. Altogether 55%, 87% and 31% of population-based COPD cases, controls and hospital patients, respectively, had a paid job at baseline. The annual incremental productivity losses were 5.8 (95% CI 1.4 to 10.1) and 330.6 (95% CI 327.8 to 333.3) days, comparing population-recruited and hospital-recruited patients with COPD to controls, respectively. There were significantly higher productivity losses associated with female sex and less education. Additional adjustments for comorbidities, exacerbations and FEV1% predicted explained all productivity losses in the population-based sample, as well as nearly 40% of the productivity losses in hospital-recruited patients. Annual incremental productivity losses were more than 50 times higher in hospital-recruited patients with COPD than that of population-recruited patients with COPD. To ensure a precise estimation of societal burden, studies on patients with COPD should be population-based.

A model-based 'varimax' sampling strategy for a heterogeneous population.

PubMed

Akram, Nuzhat A; Farooqi, Shakeel R

2014-01-01

Sampling strategies are planned to enhance the homogeneity of a sample, hence to minimize confounding errors. A sampling strategy was developed to minimize the variation within population groups. Karachi, the largest urban agglomeration in Pakistan, was used as a model population. Blood groups ABO and Rh factor were determined for 3000 unrelated individuals selected through simple random sampling. Among them five population groups, namely Balochi, Muhajir, Pathan, Punjabi and Sindhi, based on paternal ethnicity were identified. An index was designed to measure the proportion of admixture at parental and grandparental levels. Population models based on index score were proposed. For validation, 175 individuals selected through stratified random sampling were genotyped for the three STR loci CSF1PO, TPOX and TH01. ANOVA showed significant differences across the population groups for blood groups and STR loci distribution. Gene diversity was higher across the sub-population model than in the agglomerated population. At parental level gene diversities are significantly higher across No admixture models than Admixture models. At grandparental level the difference was not significant. A sub-population model with no admixture at parental level was justified for sampling the heterogeneous population of Karachi.

Prevalence and correlations of lower urinary tract symptoms, erectile dysfunction and incontinence in men from a multiethnic Asian population: Results of a regional population-based survey and comparison with industrialized nations.

PubMed

Mariappan, Paramananthan; Chong, Wooi Loong

2006-12-01

To determine, in a population-based survey, the prevalence of lower urinary tract symptoms (LUTS), erectile dysfunction (ED) and incontinence in community-dwelling men in multiethnic Malaysia, as currently available Western demographic data might not be applicable in the Asian population. A cross-sectional population-based survey was carried out in the State of Penang, Malaysia, with a target population of men aged > or = 40 years. Using a multistage study design, random systematic sampling was used to represent the target population, who were weighted based on ethnicity and rural-urban ratios so as to represent the general population distribution. Trained field-workers conducted direct interviews and administered the American Urological Association Symptom Index (AUA-SI), the International Index of Erectile Function (IIEF-5) questionnaire and questions on incontinence based on the International Continence Society 2002 definition. In all, 418 men aged > or = 40 years were interviewed, of whom 353 completed the AUA-SI questionnaire (84.5% response rate). The prevalence of mild, moderate and severe LUTS was 80.6%, 6% and 0.3%, respectively. The prevalent symptoms were frequency and nocturia. There was moderate and severe ED in 45.9% of men, whereas incontinence was reported by 8.2%. The AUA-SI correlated strongly with age (R = 0.291, P < 0.001), IIEF-5 (R = - 0.265, P < 0.001) and diabetes mellitus. The prevalence and severity of LUTS, ED and incontinence increased with age in this multiethnic Asian population, in which ED correlated strongly with LUTS. Compared to the Western population, the prevalence of LUTS was significantly lower, while the prevalence of ED and incontinence were comparable.

Inference and Analysis of Population Structure Using Genetic Data and Network Theory

PubMed Central

Greenbaum, Gili; Templeton, Alan R.; Bar-David, Shirli

2016-01-01

Clustering individuals to subpopulations based on genetic data has become commonplace in many genetic studies. Inference about population structure is most often done by applying model-based approaches, aided by visualization using distance-based approaches such as multidimensional scaling. While existing distance-based approaches suffer from a lack of statistical rigor, model-based approaches entail assumptions of prior conditions such as that the subpopulations are at Hardy-Weinberg equilibria. Here we present a distance-based approach for inference about population structure using genetic data by defining population structure using network theory terminology and methods. A network is constructed from a pairwise genetic-similarity matrix of all sampled individuals. The community partition, a partition of a network to dense subgraphs, is equated with population structure, a partition of the population to genetically related groups. Community-detection algorithms are used to partition the network into communities, interpreted as a partition of the population to subpopulations. The statistical significance of the structure can be estimated by using permutation tests to evaluate the significance of the partition’s modularity, a network theory measure indicating the quality of community partitions. To further characterize population structure, a new measure of the strength of association (SA) for an individual to its assigned community is presented. The strength of association distribution (SAD) of the communities is analyzed to provide additional population structure characteristics, such as the relative amount of gene flow experienced by the different subpopulations and identification of hybrid individuals. Human genetic data and simulations are used to demonstrate the applicability of the analyses. The approach presented here provides a novel, computationally efficient model-free method for inference about population structure that does not entail assumption of prior conditions. The method is implemented in the software NetStruct (available at https://giligreenbaum.wordpress.com/software/). PMID:26888080

The dynamic influence of human resources on evidence-based intervention sustainability and population outcomes: an agent-based modeling approach.

PubMed

McKay, Virginia R; Hoffer, Lee D; Combs, Todd B; Margaret Dolcini, M

2018-06-05

Sustaining evidence-based interventions (EBIs) is an ongoing challenge for dissemination and implementation science in public health and social services. Characterizing the relationship among human resource capacity within an agency and subsequent population outcomes is an important step to improving our understanding of how EBIs are sustained. Although human resource capacity and population outcomes are theoretically related, examining them over time within real-world experiments is difficult. Simulation approaches, especially agent-based models, offer advantages that complement existing methods. We used an agent-based model to examine the relationships among human resources, EBI delivery, and population outcomes by simulating provision of an EBI through a hypothetical agency and its staff. We used data from existing studies examining a widely implemented HIV prevention intervention to inform simulation design, calibration, and validity. Once we developed a baseline model, we used the model as a simulated laboratory by systematically varying three human resource variables: the number of staff positions, the staff turnover rate, and timing in training. We tracked the subsequent influence on EBI delivery and the level of population risk over time to describe the overall and dynamic relationships among these variables. Higher overall levels of human resource capacity at an agency (more positions) led to more extensive EBI delivery over time and lowered population risk earlier in time. In simulations representing the typical human resource investments, substantial influences on population risk were visible after approximately 2 years and peaked around 4 years. Human resources, especially staff positions, have an important impact on EBI sustainability and ultimately population health. A minimum level of human resources based on the context (e.g., size of the initial population and characteristics of the EBI) is likely needed for an EBI to have a meaningful impact on population outcomes. Furthermore, this model demonstrates how ABMs may be leveraged to inform research design and assess the impact of EBI sustainability in practice.

Inference and Analysis of Population Structure Using Genetic Data and Network Theory.

PubMed

Greenbaum, Gili; Templeton, Alan R; Bar-David, Shirli

2016-04-01

Clustering individuals to subpopulations based on genetic data has become commonplace in many genetic studies. Inference about population structure is most often done by applying model-based approaches, aided by visualization using distance-based approaches such as multidimensional scaling. While existing distance-based approaches suffer from a lack of statistical rigor, model-based approaches entail assumptions of prior conditions such as that the subpopulations are at Hardy-Weinberg equilibria. Here we present a distance-based approach for inference about population structure using genetic data by defining population structure using network theory terminology and methods. A network is constructed from a pairwise genetic-similarity matrix of all sampled individuals. The community partition, a partition of a network to dense subgraphs, is equated with population structure, a partition of the population to genetically related groups. Community-detection algorithms are used to partition the network into communities, interpreted as a partition of the population to subpopulations. The statistical significance of the structure can be estimated by using permutation tests to evaluate the significance of the partition's modularity, a network theory measure indicating the quality of community partitions. To further characterize population structure, a new measure of the strength of association (SA) for an individual to its assigned community is presented. The strength of association distribution (SAD) of the communities is analyzed to provide additional population structure characteristics, such as the relative amount of gene flow experienced by the different subpopulations and identification of hybrid individuals. Human genetic data and simulations are used to demonstrate the applicability of the analyses. The approach presented here provides a novel, computationally efficient model-free method for inference about population structure that does not entail assumption of prior conditions. The method is implemented in the software NetStruct (available at https://giligreenbaum.wordpress.com/software/). Copyright © 2016 by the Genetics Society of America.

First experiences in the implementation of biometric technology to link data from Health and Demographic Surveillance Systems with health facility data

PubMed Central

Serwaa-Bonsu, Adwoa; Herbst, Abraham J.; Reniers, Georges; Ijaa, Wilfred; Clark, Benjamin; Kabudula, Chodziwadziwa; Sankoh, Osman

2010-01-01

Background In developing countries, Health and Demographic Surveillance Systems (HDSSs) provide a framework for tracking demographic and health dynamics over time in a defined geographical area. Many HDSSs co-exist with facility-based data sources in the form of Health Management Information Systems (HMIS). Integrating both data sources through reliable record linkage could provide both numerator and denominator populations to estimate disease prevalence and incidence rates in the population and enable determination of accurate health service coverage. Objective To measure the acceptability and performance of fingerprint biometrics to identify individuals in demographic surveillance populations and those attending health care facilities serving the surveillance populations. Methodology Two HDSS sites used fingerprint biometrics for patient and/or surveillance population participant identification. The proportion of individuals for whom a fingerprint could be successfully enrolled were characterised in terms of age and sex. Results Adult (18–65 years) fingerprint enrolment rates varied between 94.1% (95% CI 93.6–94.5) for facility-based fingerprint data collection at the Africa Centre site to 96.7% (95% CI 95.9–97.6) for population-based fingerprint data collection at the Agincourt site. Fingerprint enrolment rates in children under 1 year old (Africa Centre site) were only 55.1% (95% CI 52.7–57.4). By age 5, child fingerprint enrolment rates were comparable to those of adults. Conclusion This work demonstrates the feasibility of fingerprint-based individual identification for population-based research in developing countries. Record linkage between demographic surveillance population databases and health care facility data based on biometric identification systems would allow for a more comprehensive evaluation of population health, including the ability to study health service utilisation from a population perspective, rather than the more restrictive health service perspective. PMID:20200659

Image Based Biomarker of Breast Cancer Risk: Analysis of Risk Disparity among Minority Populations

DTIC Science & Technology

2013-03-01

TITLE: Image Based Biomarker of Breast Cancer Risk: Analysis of Risk Disparity among Minority Populations PRINCIPAL INVESTIGATOR: Fengshan Liu...SUBTITLE 5a. CONTRACT NUMBER Image Based Biomarker of Breast Cancer Risk: Analysis of Risk Disparity among Minority Populations 5b. GRANT NUMBER...identifying the prevalence of women with incomplete visualization of the breast . We developed a code to estimate the breast cancer risks using the

Dementia Research: Populations, Progress, Problems, and Predictions.

PubMed

Hunter, Sally; Smailagic, Nadja; Brayne, Carol

2018-05-16

Alzheimer's disease (AD) is a clinicopathologically defined syndrome leading to cognitive impairment. Following the recent failures of amyloid-based randomized controlled trials to change the course of AD, there are growing calls for a re-evaluation of basic AD research. Epidemiology offers one approach to integrating the available evidence. Here we examine relationships between evidence from population-based, clinicopathological studies of brain aging and a range of hypotheses from all areas of AD research. We identify various problems, including a lack of systematic approach to measurement of clinical and neuropathological factors associated with dementia in experimental and clinical settings, poor understanding of the strengths and weaknesses of different observational and experimental designs, a lack of clarity in relation to disease definitions from the clinical, neuropathological, and molecular perspectives, inadequate characterization of brain aging in the human population, difficulties in translation between laboratory-based and population-based evidence bases, and a lack of communication between different sections of the dementia research community. Population studies highlight complexity and predict that therapeutic approaches based on single disease features will not be successful. Better characterization of brain aging in the human population is urgently required to select biomarkers and therapeutic targets that are meaningful to human disease. The generation of detailed and reliable evidence must be addressed before progress toward therapeutic interventions can be made.

Worldwide F(ST) estimates relative to five continental-scale populations.

PubMed

Steele, Christopher D; Court, Denise Syndercombe; Balding, David J

2014-11-01

We estimate the population genetics parameter FST (also referred to as the fixation index) from short tandem repeat (STR) allele frequencies, comparing many worldwide human subpopulations at approximately the national level with continental-scale populations. FST is commonly used to measure population differentiation, and is important in forensic DNA analysis to account for remote shared ancestry between a suspect and an alternative source of the DNA. We estimate FST comparing subpopulations with a hypothetical ancestral population, which is the approach most widely used in population genetics, and also compare a subpopulation with a sampled reference population, which is more appropriate for forensic applications. Both estimation methods are likelihood-based, in which FST is related to the variance of the multinomial-Dirichlet distribution for allele counts. Overall, we find low FST values, with posterior 97.5 percentiles < 3% when comparing a subpopulation with the most appropriate population, and even for inter-population comparisons we find FST < 5%. These are much smaller than single nucleotide polymorphism-based inter-continental FST estimates, and are also about half the magnitude of STR-based estimates from population genetics surveys that focus on distinct ethnic groups rather than a general population. Our findings support the use of FST up to 3% in forensic calculations, which corresponds to some current practice.

A two-stage cluster sampling method using gridded population data, a GIS, and Google Earth(TM) imagery in a population-based mortality survey in Iraq.

PubMed

Galway, Lp; Bell, Nathaniel; Sae, Al Shatari; Hagopian, Amy; Burnham, Gilbert; Flaxman, Abraham; Weiss, Wiliam M; Rajaratnam, Julie; Takaro, Tim K

2012-04-27

Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS) to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings.

A two-stage cluster sampling method using gridded population data, a GIS, and Google EarthTM imagery in a population-based mortality survey in Iraq

PubMed Central

2012-01-01

Background Mortality estimates can measure and monitor the impacts of conflict on a population, guide humanitarian efforts, and help to better understand the public health impacts of conflict. Vital statistics registration and surveillance systems are rarely functional in conflict settings, posing a challenge of estimating mortality using retrospective population-based surveys. Results We present a two-stage cluster sampling method for application in population-based mortality surveys. The sampling method utilizes gridded population data and a geographic information system (GIS) to select clusters in the first sampling stage and Google Earth TM imagery and sampling grids to select households in the second sampling stage. The sampling method is implemented in a household mortality study in Iraq in 2011. Factors affecting feasibility and methodological quality are described. Conclusion Sampling is a challenge in retrospective population-based mortality studies and alternatives that improve on the conventional approaches are needed. The sampling strategy presented here was designed to generate a representative sample of the Iraqi population while reducing the potential for bias and considering the context specific challenges of the study setting. This sampling strategy, or variations on it, are adaptable and should be considered and tested in other conflict settings. PMID:22540266

An isochrone data base and a rapid model for stellar population synthesis

NASA Astrophysics Data System (ADS)

Li, Zhongmu; Han, Zhanwen

2008-06-01

We first presented an isochrone data base that can be widely used for stellar population synthesis studies and colour-magnitude diagram (CMD) fitting. The data base consists of the isochrones of both single-star and binary-star simple stellar populations (ss-SSPs and bs-SSPs). The ranges for the age and metallicity of populations are 0-15 Gyr and 0.0001-0.03, respectively. All data are available for populations with two widely used initial mass functions (IMFs), that is, Salpeter IMF and Chabrier IMF. The uncertainty caused by the data base (about 0.81 per cent) is designed to be smaller than those caused by the Hurley code and widely used stellar spectra libraries (e.g. BaSeL 3.1) when it is used for stellar population synthesis. Based on the isochrone data base, we then built a rapid stellar population synthesis (RPS) model and calculated the high-resolution (0.3-Å) integrated spectral energy distributions, Lick indices and colour indices for bs-SSPs and ss-SSPs. In particular, we calculated the UBVRIJHKLM colours, ugriz colours and some composite colours that consist of magnitudes on different systems. These colours are useful for disentangling the well-known stellar age-metallicity degeneracy according to our previous work. As an example for applying the isochrone data base for CMD fitting, we fitted the CMDs of two star clusters (M67 and NGC1868) and obtained their distance moduli, colour excesses, stellar metallicities and ages. The results showed that the isochrones of bs-SSPs are closer to those of real star clusters. It suggests that we should take the effects of binary interactions into account in stellar population synthesis. We also discussed on the limitations of the application of the isochrone data base and the results of the RPS model. All the data are available at the CDS or on request to the authors. E-mail: zhongmu.li@gmail.com

Survival models for harvest management of mourning dove populations

USGS Publications Warehouse

Otis, D.L.

2002-01-01

Quantitative models of the relationship between annual survival and harvest rate of migratory game-bird populations are essential to science-based harvest management strategies. I used the best available band-recovery and harvest data for mourning doves (Zenaida macroura) to build a set of models based on different assumptions about compensatory harvest mortality. Although these models suffer from lack of contemporary data, they can be used in development of an initial set of population models that synthesize existing demographic data on a management-unit scale, and serve as a tool for prioritization of population demographic information needs. Credible harvest management plans for mourning dove populations will require a long-term commitment to population monitoring and iterative population analysis.

Building the Evidence Base for Population-Level Interventions: Barriers and Opportunities

ERIC Educational Resources Information Center

Lifsey, Sarah; Cash, Amanda; Anthony, Jodi; Mathis, Sheryl; Silva, Sandra

2015-01-01

Population-level interventions focused on policy, systems, and environmental change strategies are increasingly being used to affect and improve the health of populations. At the same time, emphasis on implementing evidence-based public health practices and programming is increasing, particularly at the federal level. Valuing strategies in the…

Infantile autism in children of immigrant parents. A population-based study from Göteborg, Sweden.

PubMed

Gillberg, C; Steffenburg, S; Börjesson, B; Andersson, L

1987-06-01

A population-based study of infantile autism from western Sweden has been completed. Urban children with autism more often than age-matched children in the general population had immigrant parents from 'exotic' countries. No such trend was seen in rural children with infantile autism.

Interim 2001-based national population projections for the United Kingdom and constituent countries.

PubMed

Shaw, Chris

2003-01-01

This article describes new 2001-based national population projections which were carried out following the publication in September 2002 of the first results of the 2001 Census. These "interim" projections, carried out by the Government Actuary in consultation with the Registrars General, take preliminary account of the results of the Census which showed that the base population used in previous projections was overestimated. The interim projections also incorporate a reduced assumption of net international migration to the United Kingdom, informed by the first results of the 2001 Census and taking account of more recent migration information. The population of the United Kingdom is now projected to increase from an estimated 58.8 million in 2001 to reach 63.2 million by 2026. The projected population at 2026 is about 1.8 million (2.8 per cent) lower than in the previous (2000-based) projections.

Assessment of diversity among populations of Rauvolfia serpentina Benth. Ex. Kurtz. from Southern Western Ghats of India, based on chemical profiling, horticultural traits and RAPD analysis.

PubMed

Nair, Vadakkemuriyil Divya; Raj, Rajan Pillai Dinesh; Panneerselvam, Rajaram; Gopi, Ragupathi

2014-01-01

Genetic, morphological and chemical variations of ten natural populations of Rauvolfia serpentina Benth. Ex. Kurtz. from Southern Western Ghats of India were assessed using RAPD markers reserpine content and morphological traits. An estimate of genetic diversity and differentiation between genotypes of breeding germplasm is of key importance for its improvement. Populations were collected from different geographical regions. Data obtained through three different methods were compared and the correlation among them was estimated. Statistical analysis showed significant differences for all horticultural characteristics among the accessions suggesting that selection for relevant characteristics could be possible. Variation in the content of Reserpine ranges from 0.192 g/100 g (population from Tusharagiri) to 1.312 g/100 g (population from Aryankavu). A high diversity within population and high genetic differentiation among them based on RAPDs were revealed caused both by habitat fragmentation of the low size of most populations and the low level of gene flow among them. The UPGMA dendrogram and PCA analysis based on reserpine content yielded higher separation among populations indicated specific adaptation of populations into clusters each of them including populations closed to their geographical origin. Genetic, chemical and morphological data were correlated based on Mantel test. Given the high differentiation among populations conservation strategies should take into account genetic diversity and chemical variation levels in relation to bioclimatic and geographic location of populations. Our results also indicate that RAPD approach along with horticultural analysis seemed to be best suited for assessing with high accuracy the genetic relationships among distinct R. serpentina accessions. © 2013.

Conservation genetics of the rare Pyreneo-Cantabrian endemic Aster pyrenaeus (Asteraceae)

PubMed Central

Escaravage, Nathalie; Cambecèdes, Jocelyne; Largier, Gérard; Pornon, André

2011-01-01

Background and aims Aster pyrenaeus (Asteraceae) is an endangered species, endemic to the Pyrenees and Cantabrian Mountain ranges (Spain). For its long-term persistence, this taxon needs an appropriate conservation strategy to be implemented. In this context, we studied the genetic structure over the entire geographical range of the species and then inferred the genetic relationships between populations. Methodology Molecular diversity was analysed for 290 individuals from 12 populations in the Pyrenees and the Cantabrian Mountains using inter simple sequence repeats (ISSRs). Bayesian-based analysis was applied to examine population structure. Principal results Analysis of genetic similarity and diversity, based on 87 polymorphic ISSR markers, suggests that despite being small and isolated, populations have an intermediate genetic diversity level (P % = 52.8 %, HE = 0.21 ± 0.01, genetic similarity between individuals = 49.6 %). Genetic variation was mainly found within populations (80–84 %), independently of mountain ranges, whereas 16–18 % was found between populations and <5 % between mountain ranges. Analyses of molecular variance indicated that population differentiation was highly significant. However, no significant correlation was found between the genetic and geographical distances among populations (Rs = 0.359, P = 0.140). Geographical structure based on assignment tests identified five different gene pools that were independent of any particular structure in the landscape. Conclusions The results suggest that population isolation is probably relatively recent, and that the outbreeding behaviour of the species maintains a high within-population genetic diversity. We assume that some long-distance dispersal, even among topographically remote populations, may be determinant for the pattern of genetic variation found in populations. Based on these findings, strategies are proposed for genetic conservation and management of the species. PMID:22476499

Population genetic testing for cancer susceptibility: founder mutations to genomes.

PubMed

Foulkes, William D; Knoppers, Bartha Maria; Turnbull, Clare

2016-01-01

The current standard model for identifying carriers of high-risk mutations in cancer-susceptibility genes (CSGs) generally involves a process that is not amenable to population-based testing: access to genetic tests is typically regulated by health-care providers on the basis of a labour-intensive assessment of an individual's personal and family history of cancer, with face-to-face genetic counselling performed before mutation testing. Several studies have shown that application of these selection criteria results in a substantial proportion of mutation carriers being missed. Population-based genetic testing has been proposed as an alternative approach to determining cancer susceptibility, and aims for a more-comprehensive detection of mutation carriers. Herein, we review the existing data on population-based genetic testing, and consider some of the barriers, pitfalls, and challenges related to the possible expansion of this approach. We consider mechanisms by which population-based genetic testing for cancer susceptibility could be delivered, and suggest how such genetic testing might be integrated into existing and emerging health-care structures. The existing models of genetic testing (including issues relating to informed consent) will very likely require considerable alteration if the potential benefits of population-based genetic testing are to be fully realized.

Predicting Population Curves.

ERIC Educational Resources Information Center

Bunton, Matt

2003-01-01

Uses graphs to involve students in inquiry-based population investigations on the Wisconsin gray wolf. Requires students to predict future changes in the wolf population, carrying capacity, and deer population. (YDS)

Emergence of cytotoxic resistance in cancer cell populations: Single-cell mechanisms and population-level consequences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lorenzi, Tommaso; Chisholm, Rebecca H.; Lorz, Alexander

We formulate an individual-based model and a population model of phenotypic evolution, under cytotoxic drugs, in a cancer cell population structured by the expression levels of survival-potential and proliferation-potential. We apply these models to a recently studied experimental system. Our results suggest that mechanisms based on fundamental laws of biology can reversibly push an actively-proliferating, and drug-sensitive, cell population to transition into a weakly-proliferative and drug-tolerant state, which will eventually facilitate the emergence of more potent, proliferating and drug-tolerant cells.

Design of PREVENCION: a population-based study of cardiovascular disease in Peru.

PubMed

Medina-Lezama, Josefina; Chirinos, Julio A; Zea Díaz, Humberto; Morey, Oscar; Bolanos, Juan F; Munoz-Atahualpa, Edgar; Chirinos-Pacheco, Julio

2005-11-02

Latin America is undergoing the epidemiologic transition that occurred earlier in developed countries, and is likely to face a gigantic epidemic of heart disease in the next few years unless urgent action is taken. The first essential component of any effective cardiovascular disease (CVD) control program is to establish reliable estimates of cardiovascular disease-related morbidity and mortality. However, such data from population-based studies in Latin America are still lacking. In this paper, we present the design and operation of PREVENCION (Estudio Peruano de Prevalencia de Enfermedades Cardiovasculares, for Peruvian Study of the Prevalence of Cardiovascular diseases). PREVENCION is an ongoing population-based study on a representative sample of the civilian non-institutionalized population of the second largest city in Peru. Its population is comparable to the rest of the Peruvian urban population and closely resembles other Latin American populations in countries such as Bolivia and Ecuador. Our study will contribute to the enormous task of understanding and preventing CVD in Latin America.

Mean population salt intake estimated from 24-h urine samples and spot urine samples: a systematic review and meta-analysis.

PubMed

Huang, Liping; Crino, Michelle; Wu, Jason H Y; Woodward, Mark; Barzi, Federica; Land, Mary-Anne; McLean, Rachael; Webster, Jacqui; Enkhtungalag, Batsaikhan; Neal, Bruce

2016-02-01

Estimating equations based on spot urine samples have been identified as a possible alternative approach to 24-h urine collections for determining mean population salt intake. This review compares estimates of mean population salt intake based upon spot and 24-h urine samples. We systematically searched for all studies that reported estimates of daily salt intake based upon both spot and 24-h urine samples for the same population. The associations between the two were quantified and compared overall and in subsets of studies. A total of 538 records were identified, 108 were assessed as full text and 29 were included. The included studies involved 10,414 participants from 34 countries and made 71 comparisons available for the primary analysis. Overall average population salt intake estimated from 24-h urine samples was 9.3 g/day compared with 9.0 g/day estimated from the spot urine samples. Estimates based upon spot urine samples had excellent sensitivity (97%) and specificity (100%) at classifying mean population salt intake as above or below the World Health Organization maximum target of 5 g/day. Compared with the 24-h samples, estimates based upon spot urine overestimated intake at lower levels of consumption and underestimated intake at higher levels of consumption. Estimates of mean population salt intake based upon spot urine samples can provide countries with a good indication of mean population salt intake and whether action on salt consumption is required. Published by Oxford University Press on behalf of the International Epidemiological Association 2015. This work is written by US Government employees and is in the public domain in the US.

[Optimum population analysis of Jilin Province, China based on comprehensive carrying capacity.

PubMed

Li, Xiu Xia; Meng, Mei

2017-10-01

The regional moderate population model was constructed using state-space method, and the weights of relevant factors were obtained using principal component analysis. The optimum population of Jilin Province during 2005-2014 was calculated and the causes for its formation were discussed. The results showed that the optimum population of Jilin Province was in deficit from 2005-2014, and the imbalance existed between the population, resources and environment. The resources carrying population was significantly higher than the economic carrying and the ecological carrying population, indicating that the economic development of Jilin Province was established at the expense of destroying the environment. Moreover, the land resources carrying population was substantially higher than the water and energy carrying population, which was at a deficit, indicating that the economic development of Jilin Province was based on the depletion of energy and water resources. In the future, water resources carrying capacity should be improved according to the local conditions, the energy efficiency should be enhanced via the development of new energy sources, the extensive and consumption-based resource utilization should be transformed to the intensive and low-carbon type, and the production mode and consumption patterns should be changed to protect the ecological environment.

The California Health Interview Survey 2001: translation of a major survey for California's multiethnic population.

PubMed

Ponce, Ninez A; Lavarreda, Shana Alex; Yen, Wei; Brown, E Richard; DiSogra, Charles; Satter, Delight E

2004-01-01

The cultural and linguistic diversity of the U.S. population presents challenges to the design and implementation of population-based surveys that serve to inform public policies. Information derived from such surveys may be less than representative if groups with limited or no English language skills are not included. The California Health Interview Survey (CHIS), first administered in 2001, is a population-based health survey of more than 55,000 California households. This article describes the process that the designers of CHIS 2001 underwent in culturally adapting the survey and translating it into an unprecedented number of languages: Spanish, Chinese, Vietnamese, Korean, and Khmer. The multiethnic and multilingual CHIS 2001 illustrates the importance of cultural and linguistic adaptation in raising the quality of population-based surveys, especially when the populations they intend to represent are as diverse as California's.

Interim 2003-based national population projections for the United Kingdom and constituent countries.

PubMed

Shaw, Chris

2004-01-01

The 2003-based national population projections, carried out by the Government Actuary in consultation with the Registrars General, and using essentially the same underlying assumptions as for the previous 2002-based projections, show the population of the United Kingdom rising from 59.6 million in 2003, passing 60 million during 2005, to reach 65.7 million by 2031. Longer-term projections suggest the population will peak around 2050 at nearly 67 million and then very gradually start to fall. The population will become older with the median age expected to rise from 38.4 years in 2003 to 43.3 years by 2031. In 2003, there were around 700 thousand (six per cent) more children aged under 16, than people of state pensionable age. However, from 2007, the population of pensionable age is projected to exceed the number of children.

Mechanosensory based orienting behaviors in fluvial and lacustrine populations of mottled sculpin (Cottus bairdi)

Treesearch

Sheryl Coombs; Gary D. Grossman

2006-01-01

We compared prey-orienting and rheotactic behaviors in a fluvial (Coweeta Creek) and lacustrine (Lake Michigan) population of mottled sculpin. Blinded sculpin from both populations exhibited unconditioned, mechanosensory based rheotaxis to low velocity flows. Whereas Lake Michigan sculpin generally showed increasing levels of positive rheotaxis to increasing velocities...

Linking population viability, habitat suitability, and landscape simulation models for conservation planning

Treesearch

Michael A. Larson; Frank R., III Thompson; Joshua J. Millspaugh; William D. Dijak; Stephen R. Shifley

2004-01-01

Methods for habitat modeling based on landscape simulations and population viability modeling based on habitat quality are well developed, but no published study of which we are aware has effectively joined them in a single, comprehensive analysis. We demonstrate the application of a population viability model for ovenbirds (Seiurus aurocapillus)...

Analyzing Population Genetics Using the Mitochondrial Control Region and Bioinformatics

ERIC Educational Resources Information Center

Sato, Takumi; Phillips, Bonnie; Latourelle, Sandra M.; Elwess, Nancy L.

2010-01-01

The 14-base pair hypervariable region in mitochondrial DNA (mtDNA) of Asian populations, specifically Japanese and Chinese students at Plattsburgh State University, was examined. Previous research on this 14-base pair region showed it to be susceptible to mutations and as a result indicated direct correlation with specific ethnic populations.…

Minor Self-Harm and Psychiatric Disorder: A Population-Based Study

ERIC Educational Resources Information Center

Skegg, Keren; Nada-Raja, Shyamala; Moffit, Terrie E.

2004-01-01

Little is known about the extent to which minor self-harm in the general population is associated with psychiatric disorder. A population-based sample of 980 young adults was interviewed independently about past-year suicidal and self-harm behavior and thoughts, and psychiatric disorders. Self-harm included self-harmful behaviors such as…

Biological objectives for bird populations

Treesearch

Jonathan Bart; Mark Koneff; Steve Wendt

2005-01-01

This paper explores the development of population based objectives for birds. The concept of population based objectives for bird conservation lies at the core of planning in the North American Bird Conservation Initiative. Clear objectives are needed as a basis for partnership, and a basis for program evaluation in an adaptive context. In the case of waterfowl,...

Techniques and results of nongame bird monitoring in North America

USGS Publications Warehouse

Robbins, C.S.; Bystrak, D.; Geissler, P.H.; Oelke, H.

1980-01-01

Long-term bird population trends based on accumulated ratios (proportional change) sometimes give a very misleading view of population change. Alternate methods of representing population change, based on the weighted means for the individual years, avoid the dangers of using ratios. Some advantages and disadvantages of various weighting techniques are discussed.

Using reference values to define disease based on the lower limit of normal biased the population attributable fraction, but not the population excess risk: the example of chronic airflow obstruction.

PubMed

Burney, Peter; Minelli, Cosetta

2018-01-01

The impact of disease on population health is most commonly estimated by the population attributable fraction (PAF), or less commonly by the excess risk, an alternative measure that estimates the absolute risk of disease in the population that can be ascribed to the exposure. Using chronic airflow obstruction as an example, we examined the impact on these estimates of defining disease based on different "normal" values. We estimated PAF and the excess risk in scenarios in which the true rate of disease was 10% in the exposed and 5% in the unexposed, and where either 50% or 20% of the population was exposed. Disease definition was based on a "lower limit of normal", using the 5th, 1st and 0.2nd centile of values in a "normal" population as thresholds to define normality. Where normality is defined by centiles of values in a "normal" population, PAF is strongly influenced by which centile is selected to define normality. This is not true for the population excess risk. Care should be taken when interpreting estimates of PAF when disease is defined from a centile of a normal population. Copyright © 2017 Elsevier Inc. All rights reserved.

An Updating System for the Gridded Population Database of China Based on Remote Sensing, GIS and Spatial Database Technologies.

PubMed

Yang, Xiaohuan; Huang, Yaohuan; Dong, Pinliang; Jiang, Dong; Liu, Honghui

2009-01-01

The spatial distribution of population is closely related to land use and land cover (LULC) patterns on both regional and global scales. Population can be redistributed onto geo-referenced square grids according to this relation. In the past decades, various approaches to monitoring LULC using remote sensing and Geographic Information Systems (GIS) have been developed, which makes it possible for efficient updating of geo-referenced population data. A Spatial Population Updating System (SPUS) is developed for updating the gridded population database of China based on remote sensing, GIS and spatial database technologies, with a spatial resolution of 1 km by 1 km. The SPUS can process standard Moderate Resolution Imaging Spectroradiometer (MODIS L1B) data integrated with a Pattern Decomposition Method (PDM) and an LULC-Conversion Model to obtain patterns of land use and land cover, and provide input parameters for a Population Spatialization Model (PSM). The PSM embedded in SPUS is used for generating 1 km by 1 km gridded population data in each population distribution region based on natural and socio-economic variables. Validation results from finer township-level census data of Yishui County suggest that the gridded population database produced by the SPUS is reliable.

The relative effects of habitat loss and fragmentation on population genetic variation in the red-cockaded woodpecker (Picoides borealis).

PubMed

Bruggeman, Douglas J; Wiegand, Thorsten; Fernández, Néstor

2010-09-01

The relative influence of habitat loss, fragmentation and matrix heterogeneity on the viability of populations is a critical area of conservation research that remains unresolved. Using simulation modelling, we provide an analysis of the influence both patch size and patch isolation have on abundance, effective population size (N(e)) and F(ST). An individual-based, spatially explicit population model based on 15 years of field work on the red-cockaded woodpecker (Picoides borealis) was applied to different landscape configurations. The variation in landscape patterns was summarized using spatial statistics based on O-ring statistics. By regressing demographic and genetics attributes that emerged across the landscape treatments against proportion of total habitat and O-ring statistics, we show that O-ring statistics provide an explicit link between population processes, habitat area, and critical thresholds of fragmentation that affect those processes. Spatial distances among land cover classes that affect biological processes translated into critical scales at which the measures of landscape structure correlated best with genetic indices. Therefore our study infers pattern from process, which contrasts with past studies of landscape genetics. We found that population genetic structure was more strongly affected by fragmentation than population size, which suggests that examining only population size may limit recognition of fragmentation effects that erode genetic variation. If effective population size is used to set recovery goals for endangered species, then habitat fragmentation effects may be sufficiently strong to prevent evaluation of recovery based on the ratio of census:effective population size alone.

Gender equality in university sportspeople's drinking.

PubMed

O'Brien, Kerry S; Hunter, Jackie; Kypri, Kypros; Ali, Ajmol

2008-11-01

In large population-based alcohol studies males are shown consistently to drink more, and more hazardously, than females. However, research from some countries suggests that gender differences in drinking are converging, with females drinking more than in the past. Large population-based research may miss gender-based changes in drinking behaviours that occur in sub-populations most at risk of hazardous drinking. We examine gender differences in a sub-population where hazardous drinking is common and endorsed, namely university sportspeople. The Alcohol Use Disorders Identification Test (AUDIT) and a drinking motives measure were used to assess hazardous drinking behaviours and drinking motives in 631 university sportspeople (females = 331, 52%). There were no gender differences in AUDIT scores. However, drinking motives differed between genders, with coping motives being a significant predictor of hazardous drinking in females but not males. Hazardous drinking, including binge drinking (46.3%) and frequent binge drinking (35%), in New Zealand university sportspeople is high for both males and females. New Zealand university sportspeople are one population where gender differences in drinking are not apparent and run counter to European population based research and research in US sporting populations. Gender role equality in the university systems, and endorsement of drinking in sporting culture, may account for the lack of gender differences in this New Zealand sporting population. Future research on gender differences in drinking should examine sub-populations where gender role differentiation is low, and socio-cultural/structural factors supporting gender equality are high.

Dressings and Products in Pediatric Wound Care

PubMed Central

King, Alice; Stellar, Judith J.; Blevins, Anne; Shah, Kara Noelle

2014-01-01

Significance: The increasing complexity of medical and surgical care provided to pediatric patients has resulted in a population at significant risk for complications such as pressure ulcers, nonhealing surgical wounds, and moisture-associated skin damage. Wound care practices for neonatal and pediatric patients, including the choice of specific dressings or other wound care products, are currently based on a combination of provider experience and preference and a small number of published clinical guidelines based on expert opinion; rigorous evidence-based clinical guidelines for wound management in these populations is lacking. Recent Advances: Advances in the understanding of the pathophysiology of wound healing have contributed to an ever-increasing number of specialized wound care products, most of which are predominantly marketed to adult patients and that have not been evaluated for safety and efficacy in the neonatal and pediatric populations. This review aims to discuss the available data on the use of both more traditional wound care products and newer wound care technologies in these populations, including medical-grade honey, nanocrystalline silver, and soft silicone-based adhesive technology. Critical Issues: Evidence-based wound care practices and demonstration of the safety, efficacy, and appropriate utilization of available wound care dressings and products in the neonatal and pediatric populations should be established to address specific concerns regarding wound management in these populations. Future Directions: The creation and implementation of evidence-based guidelines for the treatment of common wounds in the neonatal and pediatric populations is essential. In addition to an evaluation of currently marketed wound care dressings and products used in the adult population, newer wound care technologies should also be evaluated for use in neonates and children. In addition, further investigation of the specific pathophysiology of wound healing in neonates and children is indicated to promote the development of wound care dressings and products with specific applications in these populations. PMID:24761363

Population-based age group specific annual incidence rates of symptomatic age-related macular degeneration.

PubMed

Saari, Jukka M

2014-01-01

To study the population-based annual incidence rates of exudative, dry and all cases of symptomatic age-related macular degeneration (AMD) in different age and sex groups. This is a one year, prospective, population-based study on all consecutive new patients with AMD in the hospital district of Central Finland. The diagnosis was confirmed in all patients with slit lamp biomicroscopy, optical coherence tomography (OCT) using a Spectralis HRA + OCT device, and the Heidelberg Eye Explorer 1.6.2.0 program. Fluorescein angiograms were taken when needed. The population-based annual incidence rates of all cases of symptomatic AMD increased from 0.03% (95% CI, 0.01-0.05%) in the age group 50-59 years to 0.82% (95% CI, 0.55-1.09%) in the age group 85-89 years and were 0.2% (95% CI, 0.17-0.24%) in exudative, 0.11% (95% CI, 0.09-0.14%) in dry, and 0.32% (95% CI, 0.28-0.36%) in all cases of AMD in the age group 60 years and older. During the next 20 years in Central Finland the population-based annual incidence rates can be estimated to increase to 0.27% (95% CI, 0.24-0.30%) in exudative, to 0.13% (95% CI, 0.11-0.15%) in dry, and to 0.41% (95% CI, 0.37-0.45%) in all cases of AMD in the age group 60 years and older. The population-based annual incidence of AMD did not show statistically significant differences between males and females (p>0.1). The population-based age-group specific annual incidence rates of symptomatic AMD of this study may help to plan health care provision for patients of AMD.

Population pharmacokinetics of busulfan in pediatric and young adult patients undergoing hematopoietic cell transplant: a model-based dosing algorithm for personalized therapy and implementation into routine clinical use.

PubMed

Long-Boyle, Janel R; Savic, Rada; Yan, Shirley; Bartelink, Imke; Musick, Lisa; French, Deborah; Law, Jason; Horn, Biljana; Cowan, Morton J; Dvorak, Christopher C

2015-04-01

Population pharmacokinetic (PK) studies of busulfan in children have shown that individualized model-based algorithms provide improved targeted busulfan therapy when compared with conventional dose guidelines. The adoption of population PK models into routine clinical practice has been hampered by the tendency of pharmacologists to develop complex models too impractical for clinicians to use. The authors aimed to develop a population PK model for busulfan in children that can reliably achieve therapeutic exposure (concentration at steady state) and implement a simple model-based tool for the initial dosing of busulfan in children undergoing hematopoietic cell transplantation. Model development was conducted using retrospective data available in 90 pediatric and young adult patients who had undergone hematopoietic cell transplantation with busulfan conditioning. Busulfan drug levels and potential covariates influencing drug exposure were analyzed using the nonlinear mixed effects modeling software, NONMEM. The final population PK model was implemented into a clinician-friendly Microsoft Excel-based tool and used to recommend initial doses of busulfan in a group of 21 pediatric patients prospectively dosed based on the population PK model. Modeling of busulfan time-concentration data indicates that busulfan clearance displays nonlinearity in children, decreasing up to approximately 20% between the concentrations of 250-2000 ng/mL. Important patient-specific covariates found to significantly impact busulfan clearance were actual body weight and age. The percentage of individuals achieving a therapeutic concentration at steady state was significantly higher in subjects receiving initial doses based on the population PK model (81%) than in historical controls dosed on conventional guidelines (52%) (P = 0.02). When compared with the conventional dosing guidelines, the model-based algorithm demonstrates significant improvement for providing targeted busulfan therapy in children and young adults.

Thin-plate spline analysis of the cranial base in African, Asian and European populations and its relationship with different malocclusions.

PubMed

Rosas, Antonio; Bastir, Markus; Alarcón, Jose Antonio; Kuroe, Kazuto

2008-09-01

To test the hypothesis that midline basicranial orientation and posterior cranial base length are discriminating factors between adults of different populations and its potential maxillo/mandibular disharmonies. Twenty-nine 2D landmarks of the midline cranial base, the face and the mandible of dry skull X-rays from three major populations (45 Asians, 34 Africans, 64 Europeans) were digitized and analysed by geometric morphometrics. We used, first, MANOVA to test for mean shape differences between populations; then, principal components analysis (PCA) to assess the overall variation in the sample and finally, canonical variate analysis (CVA) with jack-knife validations (N=1000) to analyse the anatomical features that best distinguished among populations. Significant mean shapes differences were shown between populations (P<0.001). CVA revealed two significant axes of discrimination (P<0.001). Jack-knife validation correctly identified 92% of 15,000 unknowns. In Africans the whole cranial base is rotated into a forward-downward position, while in Asians it is rotated in the opposite way. The Europeans occupied an intermediate position. African and Asian samples showed a maxillo/mandibular prognathism. African prognathism was produced by an anterior positioned maxilla, Asian prognathism by retruded anterior cranial base and increase of the posterior cranial base length. Europeans showed a trend towards retracted mandibles with relatively shorter posterior cranial bases. The results supported the hypothesis that basicranial orientation and posterior cranial base length are valid factors to distinguish between geographic groups. The whole craniofacial configuration underlying a particular maxillo-facial disharmony must be considered in diagnosis, growth predictions and resulting treatment planning.

flowVS: channel-specific variance stabilization in flow cytometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azad, Ariful; Rajwa, Bartek; Pothen, Alex

Comparing phenotypes of heterogeneous cell populations from multiple biological conditions is at the heart of scientific discovery based on flow cytometry (FC). When the biological signal is measured by the average expression of a biomarker, standard statistical methods require that variance be approximately stabilized in populations to be compared. Since the mean and variance of a cell population are often correlated in fluorescence-based FC measurements, a preprocessing step is needed to stabilize the within-population variances.

LandScan 2016 High-Resolution Global Population Data Set

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bright, Edward A; Rose, Amy N; Urban, Marie L

The LandScan data set is a worldwide population database compiled on a 30" x 30" latitude/longitude grid. Census counts (at sub-national level) were apportioned to each grid cell based on likelihood coefficients, which are based on land cover, slope, road proximity, high-resolution imagery, and other data sets. The LandScan data set was developed as part of Oak Ridge National Laboratory (ORNL) Global Population Project for estimating ambient populations at risk.

flowVS: channel-specific variance stabilization in flow cytometry

DOE PAGES

Azad, Ariful; Rajwa, Bartek; Pothen, Alex

2016-07-28

Comparing phenotypes of heterogeneous cell populations from multiple biological conditions is at the heart of scientific discovery based on flow cytometry (FC). When the biological signal is measured by the average expression of a biomarker, standard statistical methods require that variance be approximately stabilized in populations to be compared. Since the mean and variance of a cell population are often correlated in fluorescence-based FC measurements, a preprocessing step is needed to stabilize the within-population variances.

Population based allele frequencies of disease associated polymorphisms in the Personalized Medicine Research Project.

PubMed

Cross, Deanna S; Ivacic, Lynn C; Stefanski, Elisha L; McCarty, Catherine A

2010-06-17

There is a lack of knowledge regarding the frequency of disease associated polymorphisms in populations and population attributable risk for many populations remains unknown. Factors that could affect the association of the allele with disease, either positively or negatively, such as race, ethnicity, and gender, may not be possible to determine without population based allele frequencies.Here we used a panel of 51 polymorphisms previously associated with at least one disease and determined the allele frequencies within the entire Personalized Medicine Research Project population based cohort. We compared these allele frequencies to those in dbSNP and other data sources stratified by race. Differences in allele frequencies between self reported race, region of origin, and sex were determined. There were 19544 individuals who self reported a single racial category, 19027 or (97.4%) self reported white Caucasian, and 11205 (57.3%) individuals were female. Of the 11,208 (57%) individuals with an identifiable region of origin 8337 or (74.4%) were German.41 polymorphisms were significantly different between self reported race at the 0.05 level. Stratification of our Caucasian population by self reported region of origin revealed 19 polymorphisms that were significantly different (p = 0.05) between individuals of different origins. Further stratification of the population by gender revealed few significant differences in allele frequencies between the genders. This represents one of the largest population based allele frequency studies to date. Stratification by self reported race and region of origin revealed wide differences in allele frequencies not only by race but also by region of origin within a single racial group. We report allele frequencies for our Asian/Hmong and American Indian populations; these two minority groups are not typically selected for population allele frequency detection. Population wide allele frequencies are important for the design and implementation of studies and for determining the relevance of a disease associated polymorphism for a given population.

Predicting recovery criteria for threatened and endangered plant species on the basis of past abundances and biological traits.

PubMed

Neel, Maile C; Che-Castaldo, Judy P

2013-04-01

Recovery plans for species listed under the U.S. Endangered Species Act are required to specify measurable criteria that can be used to determine when the species can be delisted. For the 642 listed endangered and threatened plant species that have recovery plans, we applied recursive partitioning methods to test whether the number of individuals or populations required for delisting can be predicted on the basis of distributional and biological traits, previous abundance at multiple time steps, or a combination of traits and previous abundances. We also tested listing status (threatened or endangered) and the year the recovery plan was written as predictors of recovery criteria. We analyzed separately recovery criteria that were stated as number of populations and as number of individuals (population-based and individual-based criteria, respectively). Previous abundances alone were relatively good predictors of population-based recovery criteria. Fewer populations, but a greater proportion of historically known populations, were required to delist species that had few populations at listing compared with species that had more populations at listing. Previous abundances were also good predictors of individual-based delisting criteria when models included both abundances and traits. The physiographic division in which the species occur was also a good predictor of individual-based criteria. Our results suggest managers are relying on previous abundances and patterns of decline as guidelines for setting recovery criteria. This may be justifiable in that previous abundances inform managers of the effects of both intrinsic traits and extrinsic threats that interact and determine extinction risk. © 2013 Society for Conservation Biology.

Prevalence of neuromyelitis optica spectrum disorder in the multi-ethnic Penang Island, Malaysia, and a review of worldwide prevalence.

PubMed

Hor, Jyh Yung; Lim, Thien Thien; Chia, Yuen Kang; Ching, Yee Ming; Cheah, Chun Fai; Tan, Kenny; Chow, Han Bing; Arip, Masita; Eow, Gaik Bee; Easaw, P E Samuel; Leite, M Isabel

2018-01-01

Neuromyelitis optica spectrum disorder (NMOSD) occurs worldwide in all ethnicities. Recently, population-based studies have shown that NMOSD is more common among non-White populations. There is scarce data about NMOSD prevalence in South East Asian populations. (1) A population-based study was undertaken to estimate NMOSD prevalence in the multi-ethnic Penang Island, Malaysia, comprising Chinese, Malays, and Indians. Medical records of NMOSD patients followed up at the Penang General Hospital (the neurology referral centre in Penang Island) were reviewed. The 2015 diagnostic criteria of the International Panel for NMO Diagnosis were used for case ascertainment. (2) A review of population-based prevalence studies of NMOSD worldwide was carried out. PubMed and conference proceedings were searched for such studies. Of the 28 NMOSD patients, 14 were residents of Penang Island on prevalence day [13 (93%) Chinese and one (7%) Malay]. All 14 patients were females and aquaporin 4 seropositive. The prevalence of NMOSD in Penang Island was 1.99/100,000 population; according to ethnicities, the prevalence in Chinese was significantly higher than in Malays (3.31/100,000 vs 0.43/100,000, respectively, p = 0.0195). Based on our and other population-based studies, among Asians, East Asian origin populations (Chinese and Japanese) appear to have higher NMOSD prevalence than other Asian ethnic groups. Worldwide, Blacks seem to have the highest NMOSD prevalence. More studies in different geographical regions and ethnic groups will be useful to further inform about potential factors in NMOSD pathogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

IBSEM: An Individual-Based Atlantic Salmon Population Model.

PubMed

Castellani, Marco; Heino, Mikko; Gilbey, John; Araki, Hitoshi; Svåsand, Terje; Glover, Kevin A

2015-01-01

Ecology and genetics can influence the fate of individuals and populations in multiple ways. However, to date, few studies consider them when modelling the evolutionary trajectory of populations faced with admixture with non-local populations. For the Atlantic salmon, a model incorporating these elements is urgently needed because many populations are challenged with gene-flow from non-local and domesticated conspecifics. We developed an Individual-Based Salmon Eco-genetic Model (IBSEM) to simulate the demographic and population genetic change of an Atlantic salmon population through its entire life-cycle. Processes such as growth, mortality, and maturation are simulated through stochastic procedures, which take into account environmental variables as well as the genotype of the individuals. IBSEM is based upon detailed empirical data from salmon biology, and parameterized to reproduce the environmental conditions and the characteristics of a wild population inhabiting a Norwegian river. Simulations demonstrated that the model consistently and reliably reproduces the characteristics of the population. Moreover, in absence of farmed escapees, the modelled populations reach an evolutionary equilibrium that is similar to our definition of a 'wild' genotype. We assessed the sensitivity of the model in the face of assumptions made on the fitness differences between farm and wild salmon, and evaluated the role of straying as a buffering mechanism against the intrusion of farm genes into wild populations. These results demonstrate that IBSEM is able to capture the evolutionary forces shaping the life history of wild salmon and is therefore able to model the response of populations under environmental and genetic stressors.

Development of a Late-Life Dementia Prediction Index with Supervised Machine Learning in the Population-Based CAIDE Study.

PubMed

Pekkala, Timo; Hall, Anette; Lötjönen, Jyrki; Mattila, Jussi; Soininen, Hilkka; Ngandu, Tiia; Laatikainen, Tiina; Kivipelto, Miia; Solomon, Alina

2017-01-01

This study aimed to develop a late-life dementia prediction model using a novel validated supervised machine learning method, the Disease State Index (DSI), in the Finnish population-based CAIDE study. The CAIDE study was based on previous population-based midlife surveys. CAIDE participants were re-examined twice in late-life, and the first late-life re-examination was used as baseline for the present study. The main study population included 709 cognitively normal subjects at first re-examination who returned to the second re-examination up to 10 years later (incident dementia n = 39). An extended population (n = 1009, incident dementia 151) included non-participants/non-survivors (national registers data). DSI was used to develop a dementia index based on first re-examination assessments. Performance in predicting dementia was assessed as area under the ROC curve (AUC). AUCs for DSI were 0.79 and 0.75 for main and extended populations. Included predictors were cognition, vascular factors, age, subjective memory complaints, and APOE genotype. The supervised machine learning method performed well in identifying comprehensive profiles for predicting dementia development up to 10 years later. DSI could thus be useful for identifying individuals who are most at risk and may benefit from dementia prevention interventions.

Analysis of urban-rural population dynamics for China.

PubMed

Shen, J

1991-12-01

The population dynamics of China are presented in a multiregional demographic model using regional estimates or mortality and migration based on the 1% population sample survey in 1987. An open ended population account is generated for period cohort a, gender g of region i (urban) and j (rural) using population, birth, death, and migration. Demographic rates and equations for flows of nonsurviving migrants of period cohort a of gender g are estimated using the forward demographic rate definition. Out-migration rates for period cohort a of gender g are defined by migration flow divided by the initial population. The death rate for period cohort A1 and A are estimated using a single region method. Death and migration rates are simultaneously estimated with an iterative procedure. The population accounts estimates and demographic rates are provided for the period ending 1986-87 for male births, males in period cohorts 10 and 20, female births, and females in period cohorts 10 and 20. The urban and rural population projection model is based on the population accounts concept and assumes fixed rates of mortality, migration, and normal fertility for the base year 1987. The results of this projection are a population of 1090 million that will grow to 1304 million in 2000, 1720 million in 2050, and 1791 million in 2087. Urban population will expand from 44.2% in 1988 to 46.6% in 2000, and 54.7% in 2087. The labor population of males 18-65 years and females 18-60 years will increase from 58.8% in 1988 to 59.7% in 2000 and decline to 58.4% by 2087. The old age population of males 65 years and females 60 years will increase from 6.5% in 1988 to 7.9% in 2000, and 16.3% in 2087. The mean age increased from 28.3 years in 1988 to 37 in 2087. Urban population may be underprojected; migration problems are recognized. Fertility also is likely to decline. An alternative projection (B) is given to account for the U-shape distribution and urban fertility of 1.8 in 2000, increasing to and stabilizing at 2.2 in 2020, such that population estimates for 2000 are 1291 and 1524 for 2087 with a peak in 2048 of 1573. A faster fertility decline is also used to generate projection C. The author's projections A, B, and C, which are based on more recent data and a more realistic model, are than the "objective projection" and than the "warning projection" generated by China's Population Census Office based on 1982 census data.

Relationship Status among Parents of Children with Autism Spectrum Disorders: A Population-Based Study

ERIC Educational Resources Information Center

Freedman, Brian H.; Kalb, Luther G.; Zablotsky, Benjamin; Stuart, Elizabeth A.

2012-01-01

Despite speculation about an 80% divorce rate among parents of children with an Autism Spectrum Disorder (ASD), very little empirical and no epidemiological research has addressed the issue of separation and divorce among this population. Data for this study was taken from the 2007 National Survey of Children's Health, a population-based,…

Population Structure of Melon-Headed Whales (Peponocephala electra) in the Hawaiian Archipelago: Evidence of Multiple Populations Based on Photo Identification

DTIC Science & Technology

2011-01-01

Hawaiian Archipelago: Evidence of multiple populations based on photo identification JESSICA M. ASCHETTINO Hawai‘i Pacific University, 45–045 Kamehameha ...Hawai‘i Pacific University, 45–045 Kamehameha Highway, Kaneohe, Hawaii 96744-5297, U.S.A. ABSTRACT Despite the presence of melon-headed whales in

Detecting population recovery using gametic disequilibrium-based effective population size estimates

Treesearch

David A. Tallmon; Robin S. Waples; Dave Gregovich; Michael K. Schwartz

2012-01-01

Recovering populations often must meet specific growth rate or abundance targets before their legal status can be changed from endangered or threatened. While the efficacy, power, and performance of population metrics to infer trends in declining populations has received considerable attention, how these same metrics perform when populations are increasing is less...

[The electromagnetic fields of the base stations of mobile radio communication and ecology. The estimation of danger of the base station EMF for population and for bioecosystems].

PubMed

Grigor'ev, Iu G; Grigor'ev, K A

2005-01-01

The estimation of the danger for the population and for the bioecosistems of the electromagnetic conditions around of the base stations was given. The insufficiency of the scientific knowledge does not allow to guarantee the safety of the population and of the bioecosystems in the conditions of a round-the-clock long-term influence of EMF RF. WHO recommends to use "Precautionary principle".

Development and use of a population based injury surveillance system: the All Wales Injury Surveillance System (AWISS)

PubMed Central

Lyons, R; Jones, S; Kemp, A; Sibert, J; Shepherd, J; Richmond, P; Bartlett, C; Palmer, S

2002-01-01

This report details the development and use of a population based emergency room surveillance system in the UK. Despite some difficulties in accessing high quality data the system has stimulated a considerable number of research and intervention projects. While surveillance systems with high quality data collection and coding parameters remain the gold standard, imperfect systems, particularly if population based, can play a substantial part in stimulating injury prevention initiatives. PMID:11928983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kostova, T; Carlsen, T

We present a study, based on simulations with SERDYCA, a spatially-explicit individual-based model of rodent dynamics, on the relation between population persistence and the presence of numerous isolated disturbances in the habitat. We are specifically interested in the effect of disturbances that do not fragment the environment on population persistence. Our results suggest that the presence of disturbances in the absence of fragmentation can actually increase the average time to extinction of the modeled population. The presence of disturbances decreases population density but can increase the chance for mating in monogamous species and consequently, the ratio of juveniles in themore » population. It thus provides a better chance for the population to restore itself after a severe period with critically low population density. We call this the ''disturbance-forced localization effect''.« less

Farm Population of the United States: 1974. Current Population Reports, Farm Population.

ERIC Educational Resources Information Center

Banks, Vera J.; And Others

Based on data derived primarily from the Current Population Survey of the Bureau of the Census, this statistical report presents demographic and labor force characteristics of the U.S. farm population and a comparison of selected characteristics of the farm and nonfarm population. Tabular data are presented as follows: (1) Population of the U.S.,…

Farm Population of the United States: 1971. Current Population Reports: Farm Population.

ERIC Educational Resources Information Center

Bureau of the Census (DOC), Suitland, MD. Population Div.

Based on data derived from the Current Population Survey of the Bureau of the Census, this statistical report presents demographic and labor force characteristics of the U.S. farm population and comparisons of the farm and nonfarm populations. Tabular data are presented as follows: (1) U.S. Population, Total and Farm: April 1960 and 1971; (2)…

Farm Population of the United States: 1972. Current Population Reports: Farm Population.

ERIC Educational Resources Information Center

Bureau of the Census (DOC), Suitland, MD. Population Div.

Based on data derived from the Current Population Survey of the Bureau of Census, this statistical report presents demographic and labor force characteristics of the U.S. farm population and comparisons of the farm and nonfarm populations. Tabular data are presented as follows: (1) U.S. Population, Total and Farm: April 1960 to 1972; (2) Persons…

Epigenetic differentiation and relationship to adaptive genetic divergence in discrete populations of the violet Viola cazorlensis.

PubMed

Herrera, Carlos M; Bazaga, Pilar

2010-08-01

*In plants, epigenetic variations based on DNA methylation are often heritable and could influence the course of evolution. Before this hypothesis can be assessed, fundamental questions about epigenetic variation remain to be addressed in a real-world context, including its magnitude, structuring within and among natural populations, and autonomy in relation to the genetic context. *Extent and patterns of cytosine methylation, and the relationship to adaptive genetic divergence between populations, were investigated for wild populations of the southern Spanish violet Viola cazorlensis (Violaceae) using the methylation-sensitive amplified polymorphism (MSAP) technique, a modification of the amplified fragment length polymorphism method (AFLP) based on the differential sensitivity of isoschizomeric restriction enzymes to site-specific cytosine methylation. *The genome of V. cazorlensis plants exhibited extensive levels of methylation, and methylation-based epigenetic variation was structured into distinct between- and within- population components. Epigenetic differentiation of populations was correlated with adaptive genetic divergence revealed by a Bayesian population-genomic analysis of AFLP data. Significant associations existed at the individual genome level between adaptive AFLP loci and the methylation state of methylation-susceptible MSAP loci. *Population-specific, divergent patterns of correlated selection on epigenetic and genetic individual variation could account for the coordinated epigenetic-genetic adaptive population differentiation revealed by this study.

Computer-aided system of evaluation for population-based all-in-one service screening (CASE-PASS): from study design to outcome analysis with bias adjustment.

PubMed

Chen, Li-Sheng; Yen, Amy Ming-Fang; Duffy, Stephen W; Tabar, Laszlo; Lin, Wen-Chou; Chen, Hsiu-Hsi

2010-10-01

Population-based routine service screening has gained popularity following an era of randomized controlled trials. The evaluation of these service screening programs is subject to study design, data availability, and the precise data analysis for adjusting bias. We developed a computer-aided system that allows the evaluation of population-based service screening to unify these aspects and facilitate and guide the program assessor to efficiently perform an evaluation. This system underpins two experimental designs: the posttest-only non-equivalent design and the one-group pretest-posttest design and demonstrates the type of data required at both the population and individual levels. Three major analyses were developed that included a cumulative mortality analysis, survival analysis with lead-time adjustment, and self-selection bias adjustment. We used SAS AF software to develop a graphic interface system with a pull-down menu style. We demonstrate the application of this system with data obtained from a Swedish population-based service screen and a population-based randomized controlled trial for the screening of breast, colorectal, and prostate cancer, and one service screening program for cervical cancer with Pap smears. The system provided automated descriptive results based on the various sources of available data and cumulative mortality curves corresponding to the study designs. The comparison of cumulative survival between clinically and screen-detected cases without a lead-time adjustment are also demonstrated. The intention-to-treat and noncompliance analysis with self-selection bias adjustments are also shown to assess the effectiveness of the population-based service screening program. Model validation was composed of a comparison between our adjusted self-selection bias estimates and the empirical results on effectiveness reported in the literature. We demonstrate a computer-aided system allowing the evaluation of population-based service screening programs with an adjustment for self-selection and lead-time bias. This is achieved by providing a tutorial guide from the study design to the data analysis, with bias adjustment. Copyright © 2010 Elsevier Inc. All rights reserved.

Population Structure With Localized Haplotype Clusters

PubMed Central

Browning, Sharon R.; Weir, Bruce S.

2010-01-01

We propose a multilocus version of FST and a measure of haplotype diversity using localized haplotype clusters. Specifically, we use haplotype clusters identified with BEAGLE, which is a program implementing a hidden Markov model for localized haplotype clustering and performing several functions including inference of haplotype phase. We apply this methodology to HapMap phase 3 data. With this haplotype-cluster approach, African populations have highest diversity and lowest divergence from the ancestral population, East Asian populations have lowest diversity and highest divergence, and other populations (European, Indian, and Mexican) have intermediate levels of diversity and divergence. These relationships accord with expectation based on other studies and accepted models of human history. In contrast, the population-specific FST estimates obtained directly from single-nucleotide polymorphisms (SNPs) do not reflect such expected relationships. We show that ascertainment bias of SNPs has less impact on the proposed haplotype-cluster-based FST than on the SNP-based version, which provides a potential explanation for these results. Thus, these new measures of FST and haplotype-cluster diversity provide an important new tool for population genetic analysis of high-density SNP data. PMID:20457877

Understanding Past Population Dynamics: Bayesian Coalescent-Based Modeling with Covariates

PubMed Central

Gill, Mandev S.; Lemey, Philippe; Bennett, Shannon N.; Biek, Roman; Suchard, Marc A.

2016-01-01

Effective population size characterizes the genetic variability in a population and is a parameter of paramount importance in population genetics and evolutionary biology. Kingman’s coalescent process enables inference of past population dynamics directly from molecular sequence data, and researchers have developed a number of flexible coalescent-based models for Bayesian nonparametric estimation of the effective population size as a function of time. Major goals of demographic reconstruction include identifying driving factors of effective population size, and understanding the association between the effective population size and such factors. Building upon Bayesian nonparametric coalescent-based approaches, we introduce a flexible framework that incorporates time-varying covariates that exploit Gaussian Markov random fields to achieve temporal smoothing of effective population size trajectories. To approximate the posterior distribution, we adapt efficient Markov chain Monte Carlo algorithms designed for highly structured Gaussian models. Incorporating covariates into the demographic inference framework enables the modeling of associations between the effective population size and covariates while accounting for uncertainty in population histories. Furthermore, it can lead to more precise estimates of population dynamics. We apply our model to four examples. We reconstruct the demographic history of raccoon rabies in North America and find a significant association with the spatiotemporal spread of the outbreak. Next, we examine the effective population size trajectory of the DENV-4 virus in Puerto Rico along with viral isolate count data and find similar cyclic patterns. We compare the population history of the HIV-1 CRF02_AG clade in Cameroon with HIV incidence and prevalence data and find that the effective population size is more reflective of incidence rate. Finally, we explore the hypothesis that the population dynamics of musk ox during the Late Quaternary period were related to climate change. [Coalescent; effective population size; Gaussian Markov random fields; phylodynamics; phylogenetics; population genetics. PMID:27368344

Variation in the cranial base orientation and facial skeleton in dry skulls sampled from three major populations.

PubMed

Kuroe, Kazuto; Rosas, Antonio; Molleson, Theya

2004-04-01

The aim of this study was to analyse the effects of cranial base orientation on the morphology of the craniofacial system in human populations. Three geographically distant populations from Europe (72), Africa (48) and Asia (24) were chosen. Five angular and two linear variables from the cranial base component and six angular and six linear variables from the facial component based on two reference lines of the vertical posterior maxillary and Frankfort horizontal planes were measured. The European sample presented dolichofacial individuals with a larger face height and a smaller face depth derived from a raised cranial base and facial cranium orientation which tended to be similar to the Asian sample. The African sample presented brachyfacial individuals with a reduced face height and a larger face depth as a result of a lowered cranial base and facial cranium orientation. The Asian sample presented dolichofacial individuals with a larger face height and depth due to a raised cranial base and facial cranium orientation. The findings of this study suggest that cranial base orientation and posterior cranial base length appear to be valid discriminating factors between different human populations.

Polymorphic butterfly reveals the missing link in ecological speciation.

PubMed

Chamberlain, Nicola L; Hill, Ryan I; Kapan, Durrell D; Gilbert, Lawrence E; Kronforst, Marcus R

2009-11-06

Ecological speciation occurs when ecologically based, divergent selection causes the evolution of reproductive isolation. There are many empirical examples of this process; however, there exists a poorly characterized stage during which the traits that distinguish species ecologically and reproductively segregate in a single population. By using a combination of genetic mapping, mate-choice experiments, field observations, and population genetics, we studied a butterfly population with a mimetic wing color polymorphism and found that the butterflies exhibited partial, color-based, assortative mate preference. These traits represent the divergent, ecologically based signal and preference components of sexual isolation that usually distinguish incipient and sibling species. The association between behavior and recognition trait in a single population may enhance the probability of speciation and provides an example of the missing link between an interbreeding population and isolated species.

The potential value of sibling controls compared with population controls for association studies of lifestyle-related risk factors: an example from the Breast Cancer Family Registry.

PubMed

Milne, Roger L; John, Esther M; Knight, Julia A; Dite, Gillian S; Southey, Melissa C; Giles, Graham G; Apicella, Carmel; West, Dee W; Andrulis, Irene L; Whittemore, Alice S; Hopper, John L

2011-10-01

A previous Australian population-based breast cancer case-control study found indirect evidence that control participation, although high, was not random. We hypothesized that unaffected sisters may provide a more appropriate comparison group than unrelated population controls. Three population-based case-control-family studies of breast cancer in women of white European origin were carried out by the Australian, Ontario and Northern California sites of the Breast Cancer Family Registry. We compared risk factors between 3643 cases, 2444 of their unaffected sisters and 2877 population controls and conducted separate case-control analyses based on population and sister controls using unconditional multivariable logistic regression. Compared with sister controls, population controls were more highly educated, had an earlier age at menarche, fewer births, their first birth at a later age and their last birth more recently. The established breast cancer associations detected using sister controls, but not detected using population controls, were decreasing risk with each of later age at menarche, more births, younger age at first birth and greater time since last birth. Since participation of population controls might be unintentionally related to some risk factors, we hypothesize that sister controls could provide more valid relative risk estimates and be recruited at lower cost. Given declining study participation by population controls, this contention is highly relevant to epidemiologic research.

Genetic variation and structure in remnant population of critically endangered Melicope zahlbruckneri

USGS Publications Warehouse

Raji, J. A.; Atkinson, Carter T.

2016-01-01

The distribution and amount of genetic variation within and between populations of plant species are important for their adaptability to future habitat changes and also critical for their restoration and overall management. This study was initiated to assess the genetic status of the remnant population of Melicope zahlbruckneri–a critically endangered species in Hawaii, and determine the extent of genetic variation and diversity in order to propose valuable conservation approaches. Estimated genetic structure of individuals based on molecular marker allele frequencies identified genetic groups with low overall differentiation but identified the most genetically diverse individuals within the population. Analysis of Amplified Fragment Length Polymorphic (AFLP) marker loci in the population based on Bayesian model and multivariate statistics classified the population into four subgroups. We inferred a mixed species population structure based on Bayesian clustering and frequency of unique alleles. The percentage of Polymorphic Fragment (PPF) ranged from 18.8 to 64.6% for all marker loci with an average of 54.9% within the population. Inclusion of all surviving M. zahlbruckneri trees in future restorative planting at new sites are suggested, and approaches for longer term maintenance of genetic variability are discussed. To our knowledge, this study represents the first report of molecular genetic analysis of the remaining population of M. zahlbruckneri and also illustrates the importance of genetic variability for conservation of a small endangered population.

Costs of detection bias in index-based population monitoring

USGS Publications Warehouse

Moore, C.T.; Kendall, W.L.

2004-01-01

Managers of wildlife populations commonly rely on indirect, count-based measures of the population in making decisions regarding conservation, harvest, or control. The main appeal in the use of such counts is their low material expense compared to methods that directly measure the population. However, their correct use rests on the rarely-tested but often-assumed premise that they proportionately reflect population size, i.e., that they constitute a population index. This study investigates forest management for the endangered Red-cockaded Woodpecker (Picoides borealis) and the Wood Thrush (Hylocichla mustelina) at the Piedmont National Wildlife Refuge in central Georgia, U.S.A. Optimal decision policies for a joint species objective were derived for two alternative models of Wood Thrush population dynamics. Policies were simulated under scenarios of unbiasedness, consistent negative bias, and habitat-dependent negative bias in observed Wood Thrush densities. Differences in simulation outcomes between biased and unbiased detection scenarios indicated the expected loss in resource objectives (here, forest habitat and birds) through decision-making based on biased population counts. Given the models and objective function used in our analysis, expected losses were as great as 11%, a degree of loss perhaps not trivial for applications such as endangered species management. Our analysis demonstrates that costs of uncertainty about the relationship between the population and its observation can be measured in units of the resource, costs which may offset apparent savings achieved by collecting uncorrected population counts.

Extreme Environment Basing:Contingency Basing in Dense Urban and Megacity Environments

DTIC Science & Technology

2016-05-24

the placement of a U.S. military contingency base. As stated above, the consideration given to the volume of displaced people caused by the base camp...population density , Dhaka, Bangladesh ........................... 29 B-1 The base camp development planning process...urban areas are not incredibly dense, a great many are. These places represent the extreme end of the urban spectrum for population density and city

Individualized population care: linking personal care to population care in general practice.

PubMed

Buetow, Stephen; Getz, Linn; Adams, Peter

2008-10-01

General practice is increasingly expected to deliver population care to individual patients. The feasibility and ethics of this policy shift have been challenged. Our aim is to suggest how to deliver population care while protecting personal care. We outline and discuss concepts of these types of care, their relation to the prevailing discourse regarding intervention benefits, and arguments for individualized population care. Individualized population care can enable general practice to meet the health targets of individual patients in the light of population-based goals. It unifies the concepts of personal care and whole population care. Personal care focuses on the individual good in particular consultations. Whole population care focuses on the overall health good of a population without reference to the individuality of each population member. These types of care constitute elements of a continuum that varies in purpose and objects of focus. The limitations of a crude dichotomy of personal care and population care are made explicit in a series of five arguments that lend support to the concept of individualized population care. We advocate a constructive but critical attitude towards the idea of population-based interventions in everyday general practice. Traditional personal care and whole population care can theoretically be integrated into individualized population care. However, this presupposes clinical-epidemiological expertise and moral awareness in practising clinicians.

Microsatellite-based genetic diversity patterns in disjunct populations of a rare orchid.

PubMed

Pandey, Madhav; Richards, Matt; Sharma, Jyotsna

2015-12-01

We investigated the patterns of genetic diversity and structure in seven disjunct populations of a rare North American orchid, Cypripedium kentuckiense by including populations that represented the periphery and the center of the its range. Eight nuclear and two chloroplast microsatellites were used. Genetic diversity was low across the sampled populations of C. kentuckiense based on both nuclear (average An = 4.0, Ho = 0.436, He = 0.448) and cpDNA microsatellites (average An = 1.57, Nh = 1.57 and H = 0.133). The number of private alleles ranged from one to four per population with a total of 17 private alleles detected at five nuclear microsatellites. One private allele at one cpDNA microsatellite was also observed. Although the absolute values for nuclear microsatellite based population differentiation were low (Fst = 0.075; ϕPT = 0.24), they were statistically significant. Pairwise Fst values ranged from 0.038 to 0.123 and each comparison was significant. We also detected isolation by distance with nDNA microsatellites based on the Mantel test (r(2) = 0.209, P = 0.05). STRUCTURE analysis and the neighbor joining trees grouped the populations similarly whereby the geographically proximal populations were genetically similar. Our data indicate that the species is genetically depauperate but the diversity is distributed more or less equally across its range. Population differentiation and isolation by distance were detectable, which indicates that genetic isolation is beginning to manifest itself across the range in this rare species.

Projections of the Population of the United States, by Age, Sex, and Race: 1983 to 2080.

ERIC Educational Resources Information Center

Spencer, Gregory

1984-01-01

Based on assumptions about fertility, mortality, and net immigration trends, statistical tables depict the future U.S. population by age, sex, and race. Figures are based on the July 1, 1982, population estimates and race definitions and are projected using the cohort-component method with alternative assumptions for future fertility, mortality,…

Molecular diversity and population structure of the forage grass Hemarthria compressa (Poaceae) in south China based on SRAP markers.

PubMed

Huang, L-K; Zhang, X-Q; Xie, W-G; Zhang, J; Cheng, L; Yan, H D

2012-08-16

Hemarthria compressa is one of the most important and widely utilized forage crops in south China, owing to its high forage yield and capability of adaptation to hot and humid conditions. We examined the population structure and genetic variation within and among 12 populations of H. compressa in south China using sequence-related amplified polymorphism (SRAP) markers. High genetic diversity was found in these samples [percentage polymorphic bands (PPB) = 82.21%, Shannon's diversity index (I) = 0.352]. However, there was relatively low level of genetic diversity at the population level (PPB = 29.17%, I = 0.155). A high degree of genetic differentiation among populations was detected based on other measures and molecular markers (Nei's genetic diversity analysis: G(ST) = 54.19%; AMOVA analysis: F(ST) = 53.35%). The SRAP markers were found to be more efficient than ISSR markers for evaluating population diversity. Based on these findings, we propose changes in sampling strategies for appraising and utilizing the genetic resources of this species.

A Place-Oriented, Mixed-Level Regionalization Method for Constructing Geographic Areas in Health Data Dissemination and Analysis

PubMed Central

Mu, Lan; Wang, Fahui; Chen, Vivien W.; Wu, Xiao-Cheng

2015-01-01

Similar geographic areas often have great variations in population size. In health data management and analysis, it is desirable to obtain regions of comparable population by decomposing areas of large population (to gain more spatial variability) and merging areas of small population (to mask privacy of data). Based on the Peano curve algorithm and modified scale-space clustering, this research proposes a mixed-level regionalization (MLR) method to construct geographic areas with comparable population. The method accounts for spatial connectivity and compactness, attributive homogeneity, and exogenous criteria such as minimum (and approximately equal) population or disease counts. A case study using Louisiana cancer data illustrates the MLR method and its strengths and limitations. A major benefit of the method is that most upper level geographic boundaries can be preserved to increase familiarity of constructed areas. Therefore, the MLR method is more human-oriented and place-based than computer-oriented and space-based. PMID:26251551

Society of Behavioral Medicine supports implementation of high quality lung cancer screening in high-risk populations.

PubMed

Watson, Karriem S; Blok, Amanda C; Buscemi, Joanna; Molina, Yamile; Fitzgibbon, Marian; Simon, Melissa A; Williams, Lance; Matthews, Kameron; Studts, Jamie L; Lillie, Sarah E; Ostroff, Jamie S; Carter-Harris, Lisa; Winn, Robert A

2016-12-01

The Society of Behavioral Medicine (SBM) supports the United States Preventive Services Task Force (USPSTF) recommendation of low-dose computed tomography (LDCT) screening of the chest for eligible populations to reduce lung cancer mortality. Consistent with efforts to translate research findings into real-world settings, SBM encourages health-care providers and health-care systems to (1) integrate evidence-based tobacco treatment as an essential component of LDCT-based lung cancer screening, (2) examine the structural barriers that may impact screening uptake, and (3) incorporate shared decision-making as a clinical platform to facilitate consultations and engagement with individuals at high risk for lung cancer about the potential benefits and harms associated with participation in a lung cancer screening program. We advise policy makers and legislators to support screening in high-risk populations by continuing to (1) expand access to high quality LDCT-based screening among underserved high-risk populations, (2) enhance cost-effectiveness by integrating evidence-based tobacco treatments into screening in high-risk populations, and (3) increase funding for research that explores implementation science and increased public awareness and access of diverse populations to participate in clinical and translational research.

The Case for Diabetes Population Health Improvement: Evidence-Based Programming for Population Outcomes in Diabetes.

PubMed

Golden, Sherita Hill; Maruthur, Nisa; Mathioudakis, Nestoras; Spanakis, Elias; Rubin, Daniel; Zilbermint, Mihail; Hill-Briggs, Felicia

2017-07-01

The goal of this review is to describe diabetes within a population health improvement framework and to review the evidence for a diabetes population health continuum of intervention approaches, including diabetes prevention and chronic and acute diabetes management, to improve clinical and economic outcomes. Recent studies have shown that compared to usual care, lifestyle interventions in prediabetes lower diabetes risk at the population-level and that group-based programs have low incremental medial cost effectiveness ratio for health systems. Effective outpatient interventions that improve diabetes control and process outcomes are multi-level, targeting the patient, provider, and healthcare system simultaneously and integrate community health workers as a liaison between the patient and community-based healthcare resources. A multi-faceted approach to diabetes management is also effective in the inpatient setting. Interventions shown to promote safe and effective glycemic control and use of evidence-based glucose management practices include provider reminder and clinical decision support systems, automated computer order entry, provider education, and organizational change. Future studies should examine the cost-effectiveness of multi-faceted outpatient and inpatient diabetes management programs to determine the best financial models for incorporating them into diabetes population health strategies.

The Population Care Coordination Process.

PubMed

Rushton, Sharron

2015-01-01

The purpose of the article was to outline a population-based approach to providing care coordination. The Population Care Coordination Process provides a framework for each provider and/or organization to provide multilevel care based on population- and patient-centered principles. The Population Care Coordination Process is scalable. It can be utilized in a smaller scale such as single provider office or in a larger scale such as an accountable care organization. There are many issues within our current health care structure that must be addressed. Care coordination has been identified as a potential solution to address the needs of complex patients within the system. The expansion to consider populations allows for a more targeted and efficient approach. The population care process entails a data-driven approach to care coordination. The inclusion of populations in the care coordination process provides an opportunity to maximize efforts and improve outcomes.

Population delineation of polar bears using satellite collar data

USGS Publications Warehouse

Bethke, R.; Taylor, Mitchell K.; Amstrup, Steven C.; Messier, François

1996-01-01

To produce reliable estimates of the size or vital rates of a given population, it is important that the boundaries of the population under study are clearly defined. This is particularly critical for large, migratory animals where levels of sustainable harvest are based on these estimates, and where small errors may have serious long-term consequences for the population. Once populations are delineated, rates of exchange between adjacent populations can be determined and accounted/corrected for when calculating abundance (e.g., based on mark-recapture data). Using satellite radio-collar locations for polar bears in the western Canadian Arctic, we illustrate one approach to delineating wildlife populations that integrates cluster analysis methods for determining group membership with home range plotting procedures to define spatial utilization. This approach is flexible with respect to the specific procedures used and provides an objective and quantitative basis for defining population boundaries.

Defining Primary Care Shortage Areas: Do GIS-based Measures Yield Different Results?

PubMed

Daly, Michael R; Mellor, Jennifer M; Millones, Marco

2018-02-12

To examine whether geographic information systems (GIS)-based physician-to-population ratios (PPRs) yield determinations of geographic primary care shortage areas that differ from those based on bounded-area PPRs like those used in the Health Professional Shortage Area (HPSA) designation process. We used geocoded data on primary care physician (PCP) locations and census block population counts from 1 US state to construct 2 shortage area indicators. The first is a bounded-area shortage indicator defined without GIS methods; the second is a GIS-based measure that measures the populations' spatial proximity to PCP locations. We examined agreement and disagreement between bounded shortage areas and GIS-based shortage areas. Bounded shortage area indicators and GIS-based shortage area indicators agree for the census blocks where the vast majority of our study populations reside. Specifically, 95% and 98% of the populations in our full and urban samples, respectively, reside in census blocks where the 2 indicators agree. Although agreement is generally high in rural areas (ie, 87% of the rural population reside in census blocks where the 2 indicators agree), agreement is significantly lower compared to urban areas. One source of disagreement suggests that bounded-area measures may "overlook" some shortages in rural areas; however, other aspects of the HPSA designation process likely mitigate this concern. Another source of disagreement arises from the border-crossing problem, and it is more prevalent. The GIS-based PPRs we employed would yield shortage area determinations that are similar to those based on bounded-area PPRs defined for Primary Care Service Areas. Disagreement rates were lower than previous studies have found. © 2018 National Rural Health Association.

SSR and morphological trait based population structure analysis of 130 diverse flax (Linum usitatissimum L.) accessions.

PubMed

Choudhary, Shashi Bhushan; Sharma, Hariom Kumar; Kumar, Arroju Anil; Maruthi, Rangappa Thimmaiah; Mitra, Jiban; Chowdhury, Isholeena; Singh, Binay Kumar; Karmakar, Pran Gobinda

2017-02-01

A total of 130 flax accessions of diverse morphotypes and worldwide origin were assessed for genetic diversity and population structure using 11 morphological traits and microsatellite markers (15 gSSRs and 7 EST-SSRs). Analysis performed after classifying these accessions on the basis of plant height, branching pattern, seed size, Indian/foreign origin into six categories called sub-populations viz. fibre type exotic, fibre type indigenous, intermediate type exotic, intermediate type indigenous, linseed type exotic and linseed type indigenous. The study assessed different diversity indices, AMOVA, population structure and included a principal coordinate analysis based on different marker systems. The highest diversity was exhibited by gSSR markers (SI=0.46; He=0.31; P=85.11). AMOVA based on all markers explained significant difference among fibre type, intermediate type and linseed type populations of flax. In terms of variation explained by different markers, EST-SSR markers (12%) better differentiated flax populations compared to morphological (9%) and gSSR (6%) markers at P=0.01. The maximum Nei's unbiased genetic distance (D=0.11) was observed between fibre type and linseed type exotic sub-populations based on EST-SSR markers. The combined structure analysis by using all markers grouped Indian fibre type accessions (63.4%) in a separate cluster along with the Indian intermediate type (48.7%), whereas Indian accessions (82.16%) of linseed type constituted an independent cluster. These findings were supported by the results of the principal coordinate analysis. Morphological markers employed in the study found complementary with microsatellite based markers in deciphering genetic diversity and population structure of the flax germplasm. Copyright © 2016 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

The Relation Between Inflation in Type-I and Type-II Error Rate and Population Divergence in Genome-Wide Association Analysis of Multi-Ethnic Populations.

PubMed

Derks, E M; Zwinderman, A H; Gamazon, E R

2017-05-01

Population divergence impacts the degree of population stratification in Genome Wide Association Studies. We aim to: (i) investigate type-I error rate as a function of population divergence (F ST ) in multi-ethnic (admixed) populations; (ii) evaluate the statistical power and effect size estimates; and (iii) investigate the impact of population stratification on the results of gene-based analyses. Quantitative phenotypes were simulated. Type-I error rate was investigated for Single Nucleotide Polymorphisms (SNPs) with varying levels of F ST between the ancestral European and African populations. Type-II error rate was investigated for a SNP characterized by a high value of F ST . In all tests, genomic MDS components were included to correct for population stratification. Type-I and type-II error rate was adequately controlled in a population that included two distinct ethnic populations but not in admixed samples. Statistical power was reduced in the admixed samples. Gene-based tests showed no residual inflation in type-I error rate.

Diagnostic test accuracy and prevalence inferences based on joint and sequential testing with finite population sampling.

PubMed

Su, Chun-Lung; Gardner, Ian A; Johnson, Wesley O

2004-07-30

The two-test two-population model, originally formulated by Hui and Walter, for estimation of test accuracy and prevalence estimation assumes conditionally independent tests, constant accuracy across populations and binomial sampling. The binomial assumption is incorrect if all individuals in a population e.g. child-care centre, village in Africa, or a cattle herd are sampled or if the sample size is large relative to population size. In this paper, we develop statistical methods for evaluating diagnostic test accuracy and prevalence estimation based on finite sample data in the absence of a gold standard. Moreover, two tests are often applied simultaneously for the purpose of obtaining a 'joint' testing strategy that has either higher overall sensitivity or specificity than either of the two tests considered singly. Sequential versions of such strategies are often applied in order to reduce the cost of testing. We thus discuss joint (simultaneous and sequential) testing strategies and inference for them. Using the developed methods, we analyse two real and one simulated data sets, and we compare 'hypergeometric' and 'binomial-based' inferences. Our findings indicate that the posterior standard deviations for prevalence (but not sensitivity and specificity) based on finite population sampling tend to be smaller than their counterparts for infinite population sampling. Finally, we make recommendations about how small the sample size should be relative to the population size to warrant use of the binomial model for prevalence estimation. Copyright 2004 John Wiley & Sons, Ltd.

IBSEM: An Individual-Based Atlantic Salmon Population Model

PubMed Central

Castellani, Marco; Heino, Mikko; Gilbey, John; Araki, Hitoshi; Svåsand, Terje; Glover, Kevin A.

2015-01-01

Ecology and genetics can influence the fate of individuals and populations in multiple ways. However, to date, few studies consider them when modelling the evolutionary trajectory of populations faced with admixture with non-local populations. For the Atlantic salmon, a model incorporating these elements is urgently needed because many populations are challenged with gene-flow from non-local and domesticated conspecifics. We developed an Individual-Based Salmon Eco-genetic Model (IBSEM) to simulate the demographic and population genetic change of an Atlantic salmon population through its entire life-cycle. Processes such as growth, mortality, and maturation are simulated through stochastic procedures, which take into account environmental variables as well as the genotype of the individuals. IBSEM is based upon detailed empirical data from salmon biology, and parameterized to reproduce the environmental conditions and the characteristics of a wild population inhabiting a Norwegian river. Simulations demonstrated that the model consistently and reliably reproduces the characteristics of the population. Moreover, in absence of farmed escapees, the modelled populations reach an evolutionary equilibrium that is similar to our definition of a ‘wild’ genotype. We assessed the sensitivity of the model in the face of assumptions made on the fitness differences between farm and wild salmon, and evaluated the role of straying as a buffering mechanism against the intrusion of farm genes into wild populations. These results demonstrate that IBSEM is able to capture the evolutionary forces shaping the life history of wild salmon and is therefore able to model the response of populations under environmental and genetic stressors. PMID:26383256

Extended Shared Socioeconomic Pathways for Coastal Impact Assessment: Spatial Coastal Population Scenarios

NASA Astrophysics Data System (ADS)

Merkens, Jan-Ludolf; Reimann, Lena; Hinkel, Jochen; Vafeidis, Athanasios T.

2016-04-01

This work extends the Shared Socioeconomic Pathways (SSPs) by developing spatial projections of global coastal population distribution for the five basic SSPs. Based on a series of coastal migration drivers, which were identified from existing literature, we develop coastal narratives for the five basic SSPs (SSP1-5). These narratives account for differences in coastal versus inland population development in urban and rural areas. To spatially distribute population we use the International Institute for Applied Systems Analysis (IIASA) national population and urbanisation projections and employ country-specific growth rates which differ for coastal and inland as well as for urban and rural regions. These rates are derived from spatial analysis of historical population data. We then adjust these rates for each SSP based on the coastal narratives. The resulting global population grids depict the projected distribution of coastal population for each SSP, until the end of the 21st century, at a spatial resolution of 30 arc seconds. These grids exhibit a three- to four-fold increase in coastal population compared to the basic SSPs. Across all SSPs, except for SSP3, coastal population peaks by the middle of the 21st century and declines afterwards. In SSP3 the coastal population grows continuously until 2100. Compared to the base year 2000 the coastal population increases considerably in all SSPs. The extended SSPs are intended to be utilised in Impact, Adaptation and Vulnerability (IAV) assessments as they allow for improved analysis of exposure to sea-level rise and coastal flooding under different physical and socioeconomic scenarios.

2002-based national population projections for the United Kingdom and constituent countries.

PubMed

Shaw, Chris

2004-01-01

The 2002-based national population projections, carried out by the Government Actuary in consultation with the Registrars General, show the population of the United Kingdom rising from 59.2 million in 2002 to nearly 65 million by 2031. Longer-term projections suggest the population will peak around 2050 at over 65 million and then gradually start to fall. The population will become gradually older with the median age expected to rise from 38.2 years in 2002 to 43.3 years by 2031. In 2002, there were around 850 thousand (8 per cent) more children aged under 16, than people of state pensionable age. However, from 2007, the population of pensionable age is projected to exceed the number of children.

2000-based national population projections for the United Kingdom and its constituent countries.

PubMed

Shaw, Chris

2002-01-01

The 2000-based national population projections, carried out by the Government Actuary at the request of the Registrars General, show the population of the United Kingdom rising from 59.8 million in 2000 to nearly 65 million by 2025. Longer-term projections suggest the population will peak at nearly 66 million around 2040 and then gradually start to fall. The population will become gradually older with the median age expected to rise from 37.4 years in 2000 to 42.4 years by 2025. In 2000, there were 1.3 million (12 per cent) more children aged under 16, than people of state pensionable age. However, by 2007, the population of state pensionable age is projected to exceed the number of children.

1998-based national population projections for the United Kingdom and constituent countries.

PubMed

Shaw, C

2000-01-01

The 1998-based national population projections, carried out by the Government Actuary in consultation with the Registrars General, show the population of the United Kingdom rising from 59.2 million in 1998 to over 63.5 million by 2021. Longer-term projections suggest the population will peak around 2036 and then gradually start to fall. The population will become gradually older with the median age expected to rise from 36.9 years in 1998 to nearly 42 years by 2021. In 1998, there were 1.4 million (13 per cent) more children aged under 16, than people of pensionable age. However, by 2008, the population of pensionable age is projected to exceed the number of children.

Cannibalism in discrete-time predator-prey systems.

PubMed

Chow, Yunshyong; Jang, Sophia R-J

2012-01-01

In this study, we propose and investigate a two-stage population model with cannibalism. It is shown that cannibalism can destabilize and lower the magnitude of the interior steady state. However, it is proved that cannibalism has no effect on the persistence of the population. Based on this model, we study two systems of predator-prey interactions where the prey population is cannibalistic. A sufficient condition based on the nontrivial boundary steady state for which both populations can coexist is derived. It is found via numerical simulations that introduction of the predator population may either stabilize or destabilize the prey dynamics, depending on cannibalism coefficients and other vital parameters.

Population Health and Tailored Medical Care in the Home: the Roles of Home-Based Primary Care and Home-Based Palliative Care.

PubMed

Ritchie, Christine S; Leff, Bruce

2018-03-01

With the growth of value-based care, payers and health systems have begun to appreciate the need to provide enhanced services to homebound adults. Recent studies have shown that home-based medical services for this high-cost, high-need population reduce costs and improve outcomes. Home-based medical care services have two flavors that are related to historical context and specialty background-home-based primary care (HBPC) and home-based palliative care (HBPalC). Although the type of services provided by HBPC and HBPalC (together termed "home-based medical care") overlap, HBPC tends to encompass longitudinal and preventive care, while HBPalC often provides services for shorter durations focused more on distress management and goals of care clarification. Given workforce constraints and growing demand, both HBPC and HBPalC will benefit from working together within a population health framework-where HBPC provides care to all patients who have trouble accessing traditional office practices and where HBPalC offers adjunctive care to patients with high symptom burden and those who need assistance with goals clarification. Policy changes that support provision of medical care in the home, population health strategies that tailor home-based medical care to the specific needs of the patients and their caregivers, and educational initiatives to assure basic palliative care competence for all home-based medical providers will improve access and reduce illness burden to this important and underrecognized population. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

The association between ALS and population density: A population based study.

PubMed

Scott, Kirsten M; Abhinav, Kumar; Wijesekera, Lokesh; Ganesalingam, Jeban; Goldstein, Laura H; Janssen, Anna; Dougherty, Andrew; Willey, Emma; Stanton, Biba R; Turner, Martin R; Ampong, Mary-Ann; Sakel, Mohammed; Orrell, Richard; Howard, Robin; Shaw, Christopher E; Nigel Leigh, P; Al-Chalabi, Ammar

2010-10-01

We aimed to assess whether rural residence is associated with amyotrophic lateral sclerosis in the south-east of England using a population based register. Previous studies in different populations have produced contradictory findings. Residence defined by London borough or non-metropolitan district at time of diagnosis was recorded for each incident case in the South-East England ALS Register between 1995 and 2005. Each of the 26 boroughs or districts of the catchment area of the register was classified according to population density. Age- and sex-adjusted incidence of ALS was calculated for each region and the relationship with population density tested by linear regression, thereby controlling for the underlying population structure. We found that population density in region of residence at diagnosis explained 25% of the variance in ALS rates (r = 0.5, p < 0.01). Thus, in this cohort in the south-east of England, people with ALS were more likely to be resident in areas of high population density at diagnosis.

The association between ALS and population density: A population based study

PubMed Central

SCOTT, KIRSTEN M.; ABHINAV, KUMAR; WIJESEKERA, LOKESH; GANESALINGAM, JEBAN; GOLDSTEIN, LAURA H.; JANSSEN, ANNA; DOUGHERTY, ANDREW; WILLEY, EMMA; STANTON, BIBA R.; TURNER, MARTIN R.; AMPONG, MARY-ANN; SAKEL, MOHAMMED; ORRELL, RICHARD; HOWARD, ROBIN; SHAW, CHRISTOPHER E.; LEIGH, P. NIGEL; AL-CHALABI, AMMAR

2011-01-01

We aimed to assess whether rural residence is associated with amyotrophic lateral sclerosis in the south-east of England using a population based register. Previous studies in different populations have produced contradictory findings. Residence defined by London borough or non-metropolitan district at time of diagnosis was recorded for each incident case in the South-East England ALS Register between 1995 and 2005. Each of the 26 boroughs or districts of the catchment area of the register was classified according to population density. Age- and sex-adjusted incidence of ALS was calculated for each region and the relationship with population density tested by linear regression, thereby controlling for the underlying population structure. We found that population density in region of residence at diagnosis explained 25% of the variance in ALS rates (r = 0.5, p < 0.01). Thus, in this cohort in the south-east of England, people with ALS were more likely to be resident in areas of high population density at diagnosis. PMID:20429684

Global diversity, population stratification, and selection of human copy number variation

PubMed Central

Sudmant, Peter H.; Mallick, Swapan; Nelson, Bradley J.; Hormozdiari, Fereydoun; Krumm, Niklas; Huddleston, John; Coe, Bradley P.; Baker, Carl; Nordenfelt, Susanne; Bamshad, Michael; Jorde, Lynn B.; Posukh, Olga L.; Sahakyan, Hovhannes; Watkins, W. Scott; Yepiskoposyan, Levon; Abdullah, M. Syafiq; Bravi, Claudio M.; Capelli, Cristian; Hervig, Tor; Wee, Joseph T. S.; Tyler-Smith, Chris; van Driem, George; Romero, Irene Gallego; Jha, Aashish R.; Karachanak-Yankova, Sena; Toncheva, Draga; Comas, David; Henn, Brenna; Kivisild, Toomas; Ruiz-Linares, Andres; Sajantila, Antti; Metspalu, Ene; Parik, Jüri; Villems, Richard; Starikovskaya, Elena B.; Ayodo, George; Beall, Cynthia M.; Di Rienzo, Anna; Hammer, Michael; Khusainova, Rita; Khusnutdinova, Elza; Klitz, William; Winkler, Cheryl; Labuda, Damian; Metspalu, Mait; Tishkoff, Sarah A.; Dryomov, Stanislav; Sukernik, Rem; Patterson, Nick; Reich, David; Eichler, Evan E.

2015-01-01

In order to explore the diversity and selective signatures of duplication and deletion human copy number variants (CNVs), we sequenced 236 individuals from 125 distinct human populations. We observed that duplications exhibit fundamentally different population genetic and selective signatures than deletions and are more likely to be stratified between human populations. Through reconstruction of the ancestral human genome, we identify megabases of DNA lost in different human lineages and pinpoint large duplications that introgressed from the extinct Denisova lineage now found at high frequency exclusively in Oceanic populations. We find that the proportion of CNV base pairs to single nucleotide variant base pairs is greater among non-Africans than it is among African populations, but we conclude that this difference is likely due to unique aspects of non-African population history as opposed to differences in CNV load. PMID:26249230

Customized versus population-based growth curves: prediction of low body fat percent at term corrected gestational age following preterm birth.

PubMed

Law, Tameeka L; Katikaneni, Lakshmi D; Taylor, Sarah N; Korte, Jeffrey E; Ebeling, Myla D; Wagner, Carol L; Newman, Roger B

2012-07-01

Compare customized versus population-based growth curves for identification of small-for-gestational-age (SGA) and body fat percent (BF%) among preterm infants. Prospective cohort study of 204 preterm infants classified as SGA or appropriate-for-gestational-age (AGA) by population-based and customized growth curves. BF% was determined by air-displacement plethysmography. Differences between groups were compared using bivariable and multivariable linear and logistic regression analyses. Customized curves reclassified 30% of the preterm infants as SGA. SGA infants identified by customized method only had significantly lower BF% (13.8 ± 6.0) than the AGA (16.2 ± 6.3, p = 0.02) infants and similar to the SGA infants classified by both methods (14.6 ± 6.7, p = 0.51). Customized growth curves were a significant predictor of BF% (p = 0.02), whereas population-based growth curves were not a significant independent predictor of BF% (p = 0.50) at term corrected gestational age. Customized growth potential improves the differentiation of SGA infants and low BF% compared with a standard population-based growth curve among a cohort of preterm infants.

Surveillance of work-related asthma in new york state.

PubMed

Tice, Cori J; Cummings, Karen R; Gelberg, Kitty H

2010-04-01

The objective of this paper is to determine the percent of adults with asthma attributable to work and describe characteristics of the work-related asthma population in New York State. Sociodemographic and control characteristics of those with and without work-related asthma are compared. Data from three population-based surveys and one case-based surveillance system were analyzed. Work-relatedness of asthma was determined by self-report for the population-based surveys and by physician report for the case-based system. Self-reported sociodemographic and control characteristics were analyzed for the population-based surveys by work-relatedness. The percent of work-relatedness among adults with current asthma in New York State ranged from 10.6% to 44.5%. Significantly more adults with work-related asthma had poorly controlled asthma than those without work-related asthma. More adults with work-related asthma also tended to be employed in the manufacturing, educational services, and public administration industries than the general population. The most frequently reported exposure was dust. Adults with work-related asthma have decreased control and adverse socioeconomic impacts compared to those with asthma that is not work-related. Increased recognition and physician reporting is necessary to further prevent the impact of work-related exposures.

Development of a Late-Life Dementia Prediction Index with Supervised Machine Learning in the Population-Based CAIDE Study

PubMed Central

Pekkala, Timo; Hall, Anette; Lötjönen, Jyrki; Mattila, Jussi; Soininen, Hilkka; Ngandu, Tiia; Laatikainen, Tiina; Kivipelto, Miia; Solomon, Alina

2016-01-01

Background and objective: This study aimed to develop a late-life dementia prediction model using a novel validated supervised machine learning method, the Disease State Index (DSI), in the Finnish population-based CAIDE study. Methods: The CAIDE study was based on previous population-based midlife surveys. CAIDE participants were re-examined twice in late-life, and the first late-life re-examination was used as baseline for the present study. The main study population included 709 cognitively normal subjects at first re-examination who returned to the second re-examination up to 10 years later (incident dementia n = 39). An extended population (n = 1009, incident dementia 151) included non-participants/non-survivors (national registers data). DSI was used to develop a dementia index based on first re-examination assessments. Performance in predicting dementia was assessed as area under the ROC curve (AUC). Results: AUCs for DSI were 0.79 and 0.75 for main and extended populations. Included predictors were cognition, vascular factors, age, subjective memory complaints, and APOE genotype. Conclusion: The supervised machine learning method performed well in identifying comprehensive profiles for predicting dementia development up to 10 years later. DSI could thus be useful for identifying individuals who are most at risk and may benefit from dementia prevention interventions. PMID:27802228

The population approach to falls injury prevention in older people: findings of a two community trial

PubMed Central

2010-01-01

Background There is a sound rationale for the population-based approach to falls injury prevention but there is currently insufficient evidence to advise governments and communities on how they can use population-based strategies to achieve desired reductions in the burden of falls-related injury. The aim of the study was to quantify the effectiveness of a streamlined (and thus potentially sustainable and cost-effective), population-based, multi-factorial falls injury prevention program for people over 60 years of age. Methods Population-based falls-prevention interventions were conducted at two geographically-defined and separate Australian sites: Wide Bay, Queensland, and Northern Rivers, NSW. Changes in the prevalence of key risk factors and changes in rates of injury outcomes within each community were compared before and after program implementation and changes in rates of injury outcomes in each community were also compared with the rates in their respective States. Results The interventions in neither community substantially decreased the rate of falls-related injury among people aged 60 years or older, although there was some evidence of reductions in occurrence of multiple falls reported by women. In addition, there was some indication of improvements in fall-related risk factors, but the magnitudes were generally modest. Conclusions The evidence suggests that low intensity population-based falls prevention programs may not be as effective as those that are intensively implemented. PMID:20167124

The effects of Medieval dams on genetic divergence and demographic history in brown trout populations

PubMed Central

2014-01-01

Background Habitat fragmentation has accelerated within the last century, but may have been ongoing over longer time scales. We analyzed the timing and genetic consequences of fragmentation in two isolated lake-dwelling brown trout populations. They are from the same river system (the Gudenå River, Denmark) and have been isolated from downstream anadromous trout by dams established ca. 600–800 years ago. For reference, we included ten other anadromous populations and two hatchery strains. Based on analysis of 44 microsatellite loci we investigated if the lake populations have been naturally genetically differentiated from anadromous trout for thousands of years, or have diverged recently due to the establishment of dams. Results Divergence time estimates were based on 1) Approximate Bayesian Computation and 2) a coalescent-based isolation-with-gene-flow model. Both methods suggested divergence times ca. 600–800 years bp, providing strong evidence for establishment of dams in the Medieval as the factor causing divergence. Bayesian cluster analysis showed influence of stocked trout in several reference populations, but not in the focal lake and anadromous populations. Estimates of effective population size using a linkage disequilibrium method ranged from 244 to > 1,000 in all but one anadromous population, but were lower (153 and 252) in the lake populations. Conclusions We show that genetic divergence of lake-dwelling trout in two Danish lakes reflects establishment of water mills and impassable dams ca. 600–800 years ago rather than a natural genetic population structure. Although effective population sizes of the two lake populations are not critically low they may ultimately limit response to selection and thereby future adaptation. Our results demonstrate that populations may have been affected by anthropogenic disturbance over longer time scales than normally assumed. PMID:24903056

The effects of Medieval dams on genetic divergence and demographic history in brown trout populations.

PubMed

Hansen, Michael M; Limborg, Morten T; Ferchaud, Anne-Laure; Pujolar, José-Martin

2014-06-05

Habitat fragmentation has accelerated within the last century, but may have been ongoing over longer time scales. We analyzed the timing and genetic consequences of fragmentation in two isolated lake-dwelling brown trout populations. They are from the same river system (the Gudenå River, Denmark) and have been isolated from downstream anadromous trout by dams established ca. 600-800 years ago. For reference, we included ten other anadromous populations and two hatchery strains. Based on analysis of 44 microsatellite loci we investigated if the lake populations have been naturally genetically differentiated from anadromous trout for thousands of years, or have diverged recently due to the establishment of dams. Divergence time estimates were based on 1) Approximate Bayesian Computation and 2) a coalescent-based isolation-with-gene-flow model. Both methods suggested divergence times ca. 600-800 years bp, providing strong evidence for establishment of dams in the Medieval as the factor causing divergence. Bayesian cluster analysis showed influence of stocked trout in several reference populations, but not in the focal lake and anadromous populations. Estimates of effective population size using a linkage disequilibrium method ranged from 244 to > 1,000 in all but one anadromous population, but were lower (153 and 252) in the lake populations. We show that genetic divergence of lake-dwelling trout in two Danish lakes reflects establishment of water mills and impassable dams ca. 600-800 years ago rather than a natural genetic population structure. Although effective population sizes of the two lake populations are not critically low they may ultimately limit response to selection and thereby future adaptation. Our results demonstrate that populations may have been affected by anthropogenic disturbance over longer time scales than normally assumed.

Evaluating and improving count-based population inference: A case study from 31 years of monitoring Sandhill Cranes

USGS Publications Warehouse

Gerber, Brian D.; Kendall, William L.

2017-01-01

Monitoring animal populations can be difficult. Limited resources often force monitoring programs to rely on unadjusted or smoothed counts as an index of abundance. Smoothing counts is commonly done using a moving-average estimator to dampen sampling variation. These indices are commonly used to inform management decisions, although their reliability is often unknown. We outline a process to evaluate the biological plausibility of annual changes in population counts and indices from a typical monitoring scenario and compare results with a hierarchical Bayesian time series (HBTS) model. We evaluated spring and fall counts, fall indices, and model-based predictions for the Rocky Mountain population (RMP) of Sandhill Cranes (Antigone canadensis) by integrating juvenile recruitment, harvest, and survival into a stochastic stage-based population model. We used simulation to evaluate population indices from the HBTS model and the commonly used 3-yr moving average estimator. We found counts of the RMP to exhibit biologically unrealistic annual change, while the fall population index was largely biologically realistic. HBTS model predictions suggested that the RMP changed little over 31 yr of monitoring, but the pattern depended on assumptions about the observational process. The HBTS model fall population predictions were biologically plausible if observed crane harvest mortality was compensatory up to natural mortality, as empirical evidence suggests. Simulations indicated that the predicted mean of the HBTS model was generally a more reliable estimate of the true population than population indices derived using a moving 3-yr average estimator. Practitioners could gain considerable advantages from modeling population counts using a hierarchical Bayesian autoregressive approach. Advantages would include: (1) obtaining measures of uncertainty; (2) incorporating direct knowledge of the observational and population processes; (3) accommodating missing years of data; and (4) forecasting population size.

Optimizing the availability of a buffered industrial process

DOEpatents

Martz, Jr., Harry F.; Hamada, Michael S.; Koehler, Arthur J.; Berg, Eric C.

2004-08-24

A computer-implemented process determines optimum configuration parameters for a buffered industrial process. A population size is initialized by randomly selecting a first set of design and operation values associated with subsystems and buffers of the buffered industrial process to form a set of operating parameters for each member of the population. An availability discrete event simulation (ADES) is performed on each member of the population to determine the product-based availability of each member. A new population is formed having members with a second set of design and operation values related to the first set of design and operation values through a genetic algorithm and the product-based availability determined by the ADES. Subsequent population members are then determined by iterating the genetic algorithm with product-based availability determined by ADES to form improved design and operation values from which the configuration parameters are selected for the buffered industrial process.

Advancing Community–Based Research with Urban American Indian Populations: Multidisciplinary Perspectives

PubMed Central

Hartmann, William E.; Wendt, Dennis C.; Saftner, Melissa A.; Marcus, John; Momper, Sandra L.

2014-01-01

The U.S. has witnessed significant growth among urban AI populations in recent decades, and concerns have been raised that these populations face equal or greater degrees of disadvantage than their reservation counterparts. Surprisingly little urban AI research or community work has been documented in the literature, and even less has been written about the influences of urban settings on community-based work with these populations. Given the deep commitments of community psychology to empowering disadvantaged groups and understanding the impact of contextual factors on the lives of individuals and groups, community psychologists are well suited to fill these gaps in the literature. Toward informing such efforts, this work offers multidisciplinary insights from distinct idiographic accounts of community-based behavioral health research with urban AI populations. Accounts are offered by three researchers and one urban AI community organization staff member, and particular attention is given to issues of community heterogeneity, geography, membership, and collaboration. Each first-person account provides “lessons learned” from the urban context in which the research occurred. Together, these accounts suggest several important areas of consideration in research with urban AIs, some of which also seem relevant to reservation-based work. Finally, the potential role of research as a tool of empowerment for urban AI populations is emphasized, suggesting future research attend to the intersections of identity, sense of community, and empowerment in urban AI populations. PMID:24659391

Population-based medical and disease management: an evaluation of cost and quality.

PubMed

Wise, Christopher G; Bahl, Vinita; Mitchell, Rita; West, Brady T; Carli, Thomas

2006-02-01

Reports by the Institute of Medicine and the Health Care Financing Administration have emphasized that the integration of medical care delivery, evidence-based medicine, and chronic care disease management may play a significant role in improving the quality of care and reducing medical care costs. The specific aim of this project is to assess the impact of an integrated set of care coordination tools and chronic disease management interventions on utilization, cost, and quality of care for a population of beneficiaries who have complementary health coverage through a plan designed to apply proactive medical and disease management processes. The utilization of health care services by the study population was compared to another population from the same geographic service area and covered by a traditional fee-for-service indemnity insurance plan that provided few medical or disease management services. Evaluation of the difference in utilization was based on the difference in the cost per-member-per-month (PMPM) in a 1-year measurement period, after adjusting for differences in fee schedules, case-mix and healthcare benefit design. After adjustments for both case-mix and benefit differences, the study group is $63 PMPM less costly than the comparison population for all members. Cost differences are largest in the 55-64 and 65 and above age groups. The study group is $115 PMPM lower than the comparison population for the age category of 65 years and older, after adjustments for case-mix and benefits. Health Plan Employer and Data Information Set (HEDIS)-based quality outcomes are near the 90th percentile for most indications. The cost outcomes of a population served by proactive, population-based disease management and complex care management, compared to an unmanaged population, demonstrates the potential of coordinated medical and disease management programs. Further studies utilizing appropriate methodologies would be beneficial.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bright, Edward A.; Rose, Amy N.; Urban, Marie L.

The LandScan data set is a worldwide population database compiled on a 30" x 30" latitude/longitube grid. Census counts (at sub-national level) were apportioned to each grid cell based on likelihood coefficients, which are based on land cover, slope, road proximity, high-resolution imagery, and other data sets. The LandScan data set was developed as part of Oak Ridge National Laboratory (ORNL) Global Population Project for estimating ambient populations at risk.

A population 'consensus', partial linkage map of Picea abies Karst. based on RAPD markers

Treesearch

G. Bucci; Thomas L. Kubisiak; W.L. Nance; P. Menozzi

1997-01-01

The authors built a "consensus" partial linkage map based on RAPD markers using 48 sibships of eight megagametophytes each from a natural population of Norway spruce. A RAPD linkage map for a single individual from the same population had previously been constructed. Using 30 random decamers that had yielded 83 RAPD markers in the single-tree map, eight...

A knowledge base for tracking the impact of genomics on population health.

PubMed

Yu, Wei; Gwinn, Marta; Dotson, W David; Green, Ridgely Fisk; Clyne, Mindy; Wulf, Anja; Bowen, Scott; Kolor, Katherine; Khoury, Muin J

2016-12-01

We created an online knowledge base (the Public Health Genomics Knowledge Base (PHGKB)) to provide systematically curated and updated information that bridges population-based research on genomics with clinical and public health applications. Weekly horizon scanning of a wide variety of online resources is used to retrieve relevant scientific publications, guidelines, and commentaries. After curation by domain experts, links are deposited into Web-based databases. PHGKB currently consists of nine component databases. Users can search the entire knowledge base or search one or more component databases directly and choose options for customizing the display of their search results. PHGKB offers researchers, policy makers, practitioners, and the general public a way to find information they need to understand the complicated landscape of genomics and population health.Genet Med 18 12, 1312-1314.

Real-time Position Based Population Data Analysis and Visualization Using Heatmap for Hazard Emergency Response

NASA Astrophysics Data System (ADS)

Ding, R.; He, T.

2017-12-01

With the increased popularity in mobile applications and services, there has been a growing demand for more advanced mobile technologies that utilize real-time Location Based Services (LBS) data to support natural hazard response efforts. Compared to traditional sources like the census bureau that often can only provide historical and static data, an LBS service can provide more current data to drive a real-time natural hazard response system to more accurately process and assess issues such as population density in areas impacted by a hazard. However, manually preparing or preprocessing the data to suit the needs of the particular application would be time-consuming. This research aims to implement a population heatmap visual analytics system based on real-time data for natural disaster emergency management. System comprised of a three-layered architecture, including data collection, data processing, and visual analysis layers. Real-time, location-based data meeting certain polymerization conditions are collected from multiple sources across the Internet, then processed and stored in a cloud-based data store. Parallel computing is utilized to provide fast and accurate access to the pre-processed population data based on criteria such as the disaster event and to generate a location-based population heatmap as well as other types of visual digital outputs using auxiliary analysis tools. At present, a prototype system, which geographically covers the entire region of China and combines population heat map based on data from the Earthquake Catalogs database has been developed. It Preliminary results indicate that the generation of dynamic population density heatmaps based on the prototype system has effectively supported rapid earthquake emergency rescue and evacuation efforts as well as helping responders and decision makers to evaluate and assess earthquake damage. Correlation analyses that were conducted revealed that the aggregation and movement of people depended on various factors, including earthquake occurrence time and location of epicenter. This research hopes to continue to build upon the success of the prototype system in order to improve and extend the system to support the analysis of earthquakes and other types of natural hazard events.

CDMetaPOP: An individual-based, eco-evolutionary model for spatially explicit simulation of landscape demogenetics

USGS Publications Warehouse

Landguth, Erin L; Bearlin, Andrew; Day, Casey; Dunham, Jason B.

2016-01-01

1. Combining landscape demographic and genetics models offers powerful methods for addressing questions for eco-evolutionary applications.2. Using two illustrative examples, we present Cost–Distance Meta-POPulation, a program to simulate changes in neutral and/or selection-driven genotypes through time as a function of individual-based movement, complex spatial population dynamics, and multiple and changing landscape drivers.3. Cost–Distance Meta-POPulation provides a novel tool for questions in landscape genetics by incorporating population viability analysis, while linking directly to conservation applications.

The problem of estimating recent genetic connectivity in a changing world.

PubMed

Samarasin, Pasan; Shuter, Brian J; Wright, Stephen I; Rodd, F Helen

2017-02-01

Accurate understanding of population connectivity is important to conservation because dispersal can play an important role in population dynamics, microevolution, and assessments of extirpation risk and population rescue. Genetic methods are increasingly used to infer population connectivity because advances in technology have made them more advantageous (e.g., cost effective) relative to ecological methods. Given the reductions in wildlife population connectivity since the Industrial Revolution and more recent drastic reductions from habitat loss, it is important to know the accuracy of and biases in genetic connectivity estimators when connectivity has declined recently. Using simulated data, we investigated the accuracy and bias of 2 common estimators of migration (movement of individuals among populations) rate. We focused on the timing of the connectivity change and the magnitude of that change on the estimates of migration by using a coalescent-based method (Migrate-n) and a disequilibrium-based method (BayesAss). Contrary to expectations, when historically high connectivity had declined recently: (i) both methods over-estimated recent migration rates; (ii) the coalescent-based method (Migrate-n) provided better estimates of recent migration rate than the disequilibrium-based method (BayesAss); (iii) the coalescent-based method did not accurately reflect long-term genetic connectivity. Overall, our results highlight the problems with comparing coalescent and disequilibrium estimates to make inferences about the effects of recent landscape change on genetic connectivity among populations. We found that contrasting these 2 estimates to make inferences about genetic-connectivity changes over time could lead to inaccurate conclusions. © 2016 Society for Conservation Biology.

Using natural language processing for identification of herpes zoster ophthalmicus cases to support population-based study.

PubMed

Zheng, Chengyi; Luo, Yi; Mercado, Cheryl; Sy, Lina; Jacobsen, Steven J; Ackerson, Brad; Lewin, Bruno; Tseng, Hung Fu

2018-06-19

Diagnosis codes are inadequate for accurately identifying herpes zoster ophthalmicus (HZO). There is significant lack of population-based studies on HZO due to the high expense of manual review of medical records. To assess whether HZO can be identified from the clinical notes using natural language processing (NLP). To investigate the epidemiology of HZO among HZ population based on the developed approach. A retrospective cohort analysis. A total of 49,914 southern California residents aged over 18 years, who had a new diagnosis of HZ. An NLP-based algorithm was developed and validated with the manually curated validation dataset (n=461). The algorithm was applied on over 1 million clinical notes associated with the study population. HZO versus non-HZO cases were compared by age, sex, race, and comorbidities. We measured the accuracy of NLP algorithm. NLP algorithm achieved 95.6% sensitivity and 99.3% specificity. Compared to the diagnosis codes, NLP identified significant more HZO cases among HZ population (13.9% versus 1.7%). Compared to the non-HZO group, the HZO group was older, had more males, had more Whites, and had more outpatient visits. We developed and validated an automatic method to identify HZO cases with high accuracy. As one of the largest studies on HZO, our finding emphasizes the importance of preventing HZ in the elderly population. This method can be a valuable tool to support population-based studies and clinical care of HZO in the era of big data. This article is protected by copyright. All rights reserved.

Agent-based modeling of the spread of the 1918-1919 flu in three Canadian fur trading communities.

PubMed

O'Neil, Caroline A; Sattenspiel, Lisa

2010-01-01

Previous attempts to study the 1918-1919 flu in three small communities in central Manitoba have used both three-community population-based and single-community agent-based models. These studies identified critical factors influencing epidemic spread, but they also left important questions unanswered. The objective of this project was to design a more realistic agent-based model that would overcome limitations of earlier models and provide new insights into these outstanding questions. The new model extends the previous agent-based model to three communities so that results can be compared to those from the population-based model. Sensitivity testing was conducted, and the new model was used to investigate the influence of seasonal settlement and mobility patterns, the geographic heterogeneity of the observed 1918-1919 epidemic in Manitoba, and other questions addressed previously. Results confirm outcomes from the population-based model that suggest that (a) social organization and mobility strongly influence the timing and severity of epidemics and (b) the impact of the epidemic would have been greater if it had arrived in the summer rather than the winter. New insights from the model suggest that the observed heterogeneity among communities in epidemic impact was not unusual and would have been the expected outcome given settlement structure and levels of interaction among communities. Application of an agent-based computer simulation has helped to better explain observed patterns of spread of the 1918-1919 flu epidemic in central Manitoba. Contrasts between agent-based and population-based models illustrate the advantages of agent-based models for the study of small populations. © 2010 Wiley-Liss, Inc.

Population Pharmacokinetics of Busulfan in Pediatric and Young Adult Patients Undergoing Hematopoietic Cell Transplant: A Model-Based Dosing Algorithm for Personalized Therapy and Implementation into Routine Clinical Use

PubMed Central

Long-Boyle, Janel; Savic, Rada; Yan, Shirley; Bartelink, Imke; Musick, Lisa; French, Deborah; Law, Jason; Horn, Biljana; Cowan, Morton J.; Dvorak, Christopher C.

2014-01-01

Background Population pharmacokinetic (PK) studies of busulfan in children have shown that individualized model-based algorithms provide improved targeted busulfan therapy when compared to conventional dosing. The adoption of population PK models into routine clinical practice has been hampered by the tendency of pharmacologists to develop complex models too impractical for clinicians to use. The authors aimed to develop a population PK model for busulfan in children that can reliably achieve therapeutic exposure (concentration-at-steady-state, Css) and implement a simple, model-based tool for the initial dosing of busulfan in children undergoing HCT. Patients and Methods Model development was conducted using retrospective data available in 90 pediatric and young adult patients who had undergone HCT with busulfan conditioning. Busulfan drug levels and potential covariates influencing drug exposure were analyzed using the non-linear mixed effects modeling software, NONMEM. The final population PK model was implemented into a clinician-friendly, Microsoft Excel-based tool and used to recommend initial doses of busulfan in a group of 21 pediatric patients prospectively dosed based on the population PK model. Results Modeling of busulfan time-concentration data indicates busulfan CL displays non-linearity in children, decreasing up to approximately 20% between the concentrations of 250–2000 ng/mL. Important patient-specific covariates found to significantly impact busulfan CL were actual body weight and age. The percentage of individuals achieving a therapeutic Css was significantly higher in subjects receiving initial doses based on the population PK model (81%) versus historical controls dosed on conventional guidelines (52%) (p = 0.02). Conclusion When compared to the conventional dosing guidelines, the model-based algorithm demonstrates significant improvement for providing targeted busulfan therapy in children and young adults. PMID:25162216

Genetic variation and forensic characteristic analysis of 25 STRs of a novel fluorescence co-amplification system in Chinese Southern Shaanxi Han population.

PubMed

Liu, Yao-Shun; Chen, Jian-Gang; Mei, Ting; Guo, Yu-Xin; Meng, Hao-Tian; Li, Jian-Fei; Wei, Yuan-Yuan; Jin, Xiao-Ye; Zhu, Bo-Feng; Zhang, Li-Ping

2017-08-15

We analyzed the genetic polymorphisms of 15 autosomal and 10 Y-chromosomal STR loci in 214 individuals of Han population from Southern Shaanxi of China and studied the genetic relationships between Southern Shaanxi Han and other populations. We observed a total of 150 alleles at 15 autosomal STR loci with the corresponding allelic frequencies ranging from 0.0023 to 0.5210, and the combined power of discrimination and exclusion for the 15 autosomal STR loci were 0.99999999999999998866 and 0.999998491, respectively. For the 10 Y-STR loci, totally 100 different haplotypes were obtained, of which 94 were unique. The discriminatory capacity and haplotype diversity values of the 10 Y-STR loci were 0.9259 and 0.998269, respectively. The results demonstrated high genetic diversities of the 25 STR loci in the population for forensic applications. We constructed neighbor-joining tree and conducted principal component analysis based on 15 autosomal STR loci and conducted multidimensional scaling analysis and constructed neighbor-joining tree based on 10 Y-STR loci. The results of population genetic analyses based on both autosomal and Y-chromosome STRs indicated that the studied Southern Shaanxi Han population had relatively closer genetic relationship with Eastern Han population, and distant relationships with Croatian, Serbian and Moroccan populations.

Population and National Development--The Dilemma of Developing Countries. Occasional Essay Number 2.

ERIC Educational Resources Information Center

Sai, Fred T.

This essay describes the relationship of population to the overall development process and is based on a special university lecture given at the London School of Hygiene in February, 1974. The contents include discussions of population trends, reasons for the population explosion, the structure of populations, development inequalities,…

How Academic Health Systems Can Achieve Population Health in Vulnerable Populations Through Value-Based Care: The Critical Importance of Establishing Trusted Agency.

PubMed

Wesson, Donald E; Kitzman, Heather E

2018-01-16

Improving population health may require health systems to proactively engage patient populations as partners in the implementation of healthy behaviors as a shared value using strategies that incentivize healthy outcomes for the population as a whole. The current reactive health care model, which focuses on restoring the health of individuals after it has been lost, will not achieve the goal of improved population health. To achieve this goal, health systems must proactively engage in partnerships with the populations they serve. Health systems will need the help of community entities and individuals who have the trust of the population being served to act on behalf of the health system if they are to achieve this effective working partnership. The need for these trusted agents is particularly pertinent for vulnerable and historically underserved segments of the population. In this Invited Commentary, the authors discuss ways by which health systems might identify, engage, and leverage trusted agents to improve the health of the population through value-based care.

Low resolution 1H NMR assignment of proton populations in pound cake and its polymeric ingredients.

PubMed

Luyts, A; Wilderjans, E; Waterschoot, J; Van Haesendonck, I; Brijs, K; Courtin, C M; Hills, B; Delcour, J A

2013-08-15

Based on a model system approach, five different proton populations were distinguished in pound cake crumb using one dimensional low resolution (1)H NMR spectroscopy. In free induction decay (FID) measurements, proton populations were assigned to (i) non-exchanging CH protons of crystalline starch, proteins and crystalline fat and (ii) non-exchanging CH protons of amorphous starch and gluten, which are in little contact with water. In Carr-Purcell-Meiboom-Gill (CPMG) measurements, three proton populations were distinguished. The CPMG population with the lowest mobility and the FID population with the highest mobility represent the same proton population. The two CPMG proton populations with the highest mobility were assigned to exchanging protons (i.e., protons of water, starch, gluten, egg proteins and sugar) and protons of lipids (i.e., protons of egg yolk lipids and amorphous lipid fraction of margarine) respectively. Based on their spin-lattice relaxation times (T1), two dimensional (1)H NMR spectroscopy further resolved the two proton populations with the highest mobility into three and two proton populations, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Scalable Entity-Based Modeling of Population-Based Systems, Final LDRD Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cleary, A J; Smith, S G; Vassilevska, T K

2005-01-27

The goal of this project has been to develop tools, capabilities and expertise in the modeling of complex population-based systems via scalable entity-based modeling (EBM). Our initial focal application domain has been the dynamics of large populations exposed to disease-causing agents, a topic of interest to the Department of Homeland Security in the context of bioterrorism. In the academic community, discrete simulation technology based on individual entities has shown initial success, but the technology has not been scaled to the problem sizes or computational resources of LLNL. Our developmental emphasis has been on the extension of this technology to parallelmore » computers and maturation of the technology from an academic to a lab setting.« less

An obesity/cardiometabolic risk reduction disease management program: a population-based approach.

PubMed

Villagra, Victor G

2009-04-01

Obesity is a critical health concern that has captured the attention of public and private healthcare payers who are interested in controlling costs and mitigating the long-term economic consequences of the obesity epidemic. Population-based approaches to obesity management have been proposed that take advantage of a chronic care model (CCM), including patient self-care, the use of community-based resources, and the realization of care continuity through ongoing communications with patients, information technology, and public policy changes. Payer-sponsored disease management programs represent an important conduit to delivering population-based care founded on similar CCM concepts. Disease management is founded on population-based disease identification, evidence-based care protocols, and collaborative practices between clinicians. While substantial clinician training, technology infrastructure commitments, and financial support at the payer level will be needed for the success of disease management programs in obesity and cardiometabolic risk reduction, these barriers can be overcome with the proper commitment. Disease management programs represent an important tool to combat the growing societal risks of overweight and obesity.

Tracking rural-to-urban migration in China: Lessons from the 2005 inter-census population survey.

PubMed

Ebenstein, Avraham; Zhao, Yaohui

2015-01-01

We examined migration in China using the 2005 inter-census population survey, in which migrants were registered at both their place of original (hukou) residence and at their destination. We find evidence that the estimated number of internal migrants in China is extremely sensitive to the enumeration method. We estimate that the traditional destination-based survey method fails to account for more than a third of migrants found using comparable origin-based methods. The 'missing' migrants are disproportionately young, male, and holders of rural hukou. We find that origin-based methods are more effective at capturing migrants who travel short distances for short periods, whereas destination-based methods are more effective when entire households have migrated and no remaining family members are located at the hukou location. We conclude with a set of policy recommendations for the design of population surveys in countries with large migrant populations.

Differences between seven measures of self-reported numbers of clients of female sex workers in southern India: implications for individual- and population-level analysis.

PubMed

Deering, Kathleen N; Vickerman, P; Pickles, M; Moses, S; Blanchard, J F; Ramesh, B M; Isac, S; Boily, M-C

2013-02-01

Quantifying sexual activity of sub-populations with high-risk sexual behaviour is important in understanding HIV epidemiology. This study examined inconsistency of seven outcomes measuring self-reported clients per month (CPM) of female sex workers (FSWs) in southern India and implications for individual/population-level analysis. Multivariate negative binomial regression was used to compare key social/environmental factors associated with each outcome. A transmission dynamics model was used to assess the impact of differences between outcomes on population-level FSW/client HIV prevalence. Outcomes based on 'clients per last working day' produced lower estimates than those based on 'clients per typical day'. Although the outcomes were strongly correlated, their averages differed by approximately two-fold (range 39.0-79.1 CPM). The CPM measure chosen did not greatly influence standard epidemiological 'risk factor' analysis. Differences across outcomes influenced HIV prevalence predictions. Due to this uncertainty, we recommend basing population-based estimates on the range of outcomes, particularly when assessing the impact of interventions.

Which Sámi? Sámi inclusion criteria in population-based studies of Sámi health and living conditions in Norway – an exploratory study exemplified with data from the SAMINOR study

PubMed Central

Pettersen, Torunn; Brustad, Magritt

2013-01-01

Background In a situation where national censuses do not record information on ethnicity, studies of the indigenous Sámi people's health and living conditions tend to use varying Sámi inclusion criteria and categorizations. Consequently, the basis on which Sámi study participants are included and categorized when Sámi health and living conditions are explored and compared differs. This may influence the results and conclusions drawn. Objective To explore some numerical consequences of applying principles derived from Norway's Sámi Act as a foundation for formalized inclusion criteria in population-based Sámi studies in Norway. Design We established 1 geographically based (G1) and 3 individual-based Sámi example populations (I1–I3) by applying diverse Sámi inclusion criteria to data from 17 rural municipalities in Norway north of the Arctic Circle. The data were collected for a population-based study of health and living conditions in 2003–2004 (the SAMINOR study). Our sample consisted of 14,797 participants aged 36–79 years. Results The size of the individual-based populations varied significantly. I1 (linguistic connection Sámi) made up 35.5% of the sample, I2 (self-identified Sámi) made up 21.0% and I3 (active language Sámi) 17.7%. They were also noticeably unevenly distributed between the 5 Sámi regions defined for this study. The differences for the other characteristics studied were more ambiguous. For the population G1 (residents in the Sámi language area) the only significant difference found between the Sámi and the corresponding non-Sámi population was for household income (OR=0.69, 95% CI: 0.63–0.74). For the populations I1–I3 there were significant differences on all measures except for I2 and education (OR=1.09, 95% CI: 0.99–1.21). Conclusions The choice of Sámi inclusion criterion had a clear impact on the size and geographical distribution of the defined populations but lesser influence on the selected characteristics for the Sámi populations relative to the respective non-Sámi ones. PMID:24282785

Gaussian process-based Bayesian nonparametric inference of population size trajectories from gene genealogies.

PubMed

Palacios, Julia A; Minin, Vladimir N

2013-03-01

Changes in population size influence genetic diversity of the population and, as a result, leave a signature of these changes in individual genomes in the population. We are interested in the inverse problem of reconstructing past population dynamics from genomic data. We start with a standard framework based on the coalescent, a stochastic process that generates genealogies connecting randomly sampled individuals from the population of interest. These genealogies serve as a glue between the population demographic history and genomic sequences. It turns out that only the times of genealogical lineage coalescences contain information about population size dynamics. Viewing these coalescent times as a point process, estimating population size trajectories is equivalent to estimating a conditional intensity of this point process. Therefore, our inverse problem is similar to estimating an inhomogeneous Poisson process intensity function. We demonstrate how recent advances in Gaussian process-based nonparametric inference for Poisson processes can be extended to Bayesian nonparametric estimation of population size dynamics under the coalescent. We compare our Gaussian process (GP) approach to one of the state-of-the-art Gaussian Markov random field (GMRF) methods for estimating population trajectories. Using simulated data, we demonstrate that our method has better accuracy and precision. Next, we analyze two genealogies reconstructed from real sequences of hepatitis C and human Influenza A viruses. In both cases, we recover more believed aspects of the viral demographic histories than the GMRF approach. We also find that our GP method produces more reasonable uncertainty estimates than the GMRF method. Copyright © 2013, The International Biometric Society.

Capturing ecology in modeling approaches applied to environmental risk assessment of endocrine active chemicals in fish.

PubMed

Mintram, Kate S; Brown, A Ross; Maynard, Samuel K; Thorbek, Pernille; Tyler, Charles R

2018-02-01

Endocrine active chemicals (EACs) are widespread in freshwater environments and both laboratory and field based studies have shown reproductive effects in fish at environmentally relevant exposures. Environmental risk assessment (ERA) seeks to protect wildlife populations and prospective assessments rely on extrapolation from individual-level effects established for laboratory fish species to populations of wild fish using arbitrary safety factors. Population susceptibility to chemical effects, however, depends on exposure risk, physiological susceptibility, and population resilience, each of which can differ widely between fish species. Population models have significant potential to address these shortfalls and to include individual variability relating to life-history traits, demographic and density-dependent vital rates, and behaviors which arise from inter-organism and organism-environment interactions. Confidence in population models has recently resulted in the EU Commission stating that results derived from reliable models may be considered when assessing the relevance of adverse effects of EACs at the population level. This review critically assesses the potential risks posed by EACs for fish populations, considers the ecological factors influencing these risks and explores the benefits and challenges of applying population modeling (including individual-based modeling) in ERA for EACs in fish. We conclude that population modeling offers a way forward for incorporating greater environmental relevance in assessing the risks of EACs for fishes and for identifying key risk factors through sensitivity analysis. Individual-based models (IBMs) allow for the incorporation of physiological and behavioral endpoints relevant to EAC exposure effects, thus capturing both direct and indirect population-level effects.

Counting the stunted children in a population: a criticism of old and new approaches and a conciliatory proposal.

PubMed

Monteiro, C A

1991-01-01

Two methods for estimating the prevalence of growth retardation in a population are evaluated: the classical method, which is based on the proportion of children whose height is more than 2 standard deviations below the expected mean of a reference population; and a new method recently proposed by Mora, which is based on the whole height distribution of observed and reference populations. Application of the classical method to several simulated populations leads to the conclusion that in most situations in developing countries the prevalence of growth retardation is grossly underestimated, and reflects only the presence of severe growth deficits. A second constraint with this method is a marked reduction of the relative differentials between more and less exposed strata. Application of Mora's method to the same simulated populations reduced but did not eliminate these constraints. A novel method for estimating the prevalence of growth retardation, which is based also on the whole height distribution of observed and reference populations, is also described and evaluated. This method produces better estimates of the true prevalence of growth retardation with no reduction in relative differentials.

Population-genetic properties of differentiated copy number variations in cattle.

PubMed

Xu, Lingyang; Hou, Yali; Bickhart, Derek M; Zhou, Yang; Hay, El Hamidi Abdel; Song, Jiuzhou; Sonstegard, Tad S; Van Tassell, Curtis P; Liu, George E

2016-03-23

While single nucleotide polymorphism (SNP) is typically the variant of choice for population genetics, copy number variation (CNV) which comprises insertion, deletion and duplication of genomic sequence, is an informative type of genetic variation. CNVs have been shown to be both common in mammals and important for understanding the relationship between genotype and phenotype. However, CNV differentiation, selection and its population genetic properties are not well understood across diverse populations. We performed a population genetics survey based on CNVs derived from the BovineHD SNP array data of eight distinct cattle breeds. We generated high resolution results that show geographical patterns of variations and genome-wide admixture proportions within and among breeds. Similar to the previous SNP-based studies, our CNV-based results displayed a strong correlation of population structure and geographical location. By conducting three pairwise comparisons among European taurine, African taurine, and indicine groups, we further identified 78 unique CNV regions that were highly differentiated, some of which might be due to selection. These CNV regions overlapped with genes involved in traits related to parasite resistance, immunity response, body size, fertility, and milk production. Our results characterize CNV diversity among cattle populations and provide a list of lineage-differentiated CNVs.

Texting for Health: An Evaluation of a Population Approach to Type 2 Diabetes Risk Reduction With a Personalized Message.

PubMed

Khurshid, Anjum; Brown, Lisanne; Mukherjee, Snigdha; Abebe, Nebeyou; Kulick, David

2015-11-01

txt4health is an innovative, 14-week, interactive, population-based mobile health program for individuals at risk of type 2 diabetes, developed under the Beacon Community Program in the Greater New Orleans, La., area. A comprehensive social marketing campaign sought to enroll hard-to-reach, at-risk populations using a combination of mass media and face-to-face engagement in faith-based and retail environments. Little is known about the effectiveness of social marketing for mobile technology application in the general population. A systematic evaluation of the campaign identified successes and barriers to implementing a population-based mobile health program. Face-to-face engagement helped increase program enrollment after the initial launch; otherwise, enrollment leveled off over time. Results show positive trends in reaching target populations and in the use of mobile phones to record personal health information and set goals for reducing the risk of type 2 diabetes. The lessons from the txt4health campaign can help inform the development and programmatic strategies to provide a person-level intervention using a population-level approach for individuals at risk for diabetes as well as aid in chronic disease management.

mRNA-Based Parallel Detection of Active Methanotroph Populations by Use of a Diagnostic Microarray

PubMed Central

Bodrossy, Levente; Stralis-Pavese, Nancy; Konrad-Köszler, Marianne; Weilharter, Alexandra; Reichenauer, Thomas G.; Schöfer, David; Sessitsch, Angela

2006-01-01

A method was developed for the mRNA-based application of microbial diagnostic microarrays to detect active microbial populations. DNA- and mRNA-based analyses of environmental samples were compared and confirmed via quantitative PCR. Results indicated that mRNA-based microarray analyses may provide additional information on the composition and functioning of microbial communities. PMID:16461725

Pronounced fixation, strong population differentiation and complex population history in the Canary Islands blue tit subspecies complex.

PubMed

Hansson, Bengt; Ljungqvist, Marcus; Illera, Juan-Carlos; Kvist, Laura

2014-01-01

Evolutionary molecular studies of island radiations may lead to insights in the role of vicariance, founder events, population size and drift in the processes of population differentiation. We evaluate the degree of population genetic differentiation and fixation of the Canary Islands blue tit subspecies complex using microsatellite markers and aim to get insights in the population history using coalescence based methods. The Canary Island populations were strongly genetically differentiated and had reduced diversity with pronounced fixation including many private alleles. In population structure models, the relationship between the central island populations (La Gomera, Tenerife and Gran Canaria) and El Hierro was difficult to disentangle whereas the two European populations showed consistent clustering, the two eastern islands (Fuerteventura and Lanzarote) and Morocco weak clustering, and La Palma a consistent unique lineage. Coalescence based models suggested that the European mainland forms an outgroup to the Afrocanarian population, a split between the western island group (La Palma and El Hierro) and the central island group, and recent splits between the three central islands, and between the two eastern islands and Morocco, respectively. It is clear that strong genetic drift and low level of concurrent gene flow among populations have shaped complex allelic patterns of fixation and skewed frequencies over the archipelago. However, understanding the population history remains challenging; in particular, the pattern of extreme divergence with low genetic diversity and yet unique genetic material in the Canary Island system requires an explanation. A potential scenario is population contractions of a historically large and genetically variable Afrocanarian population, with vicariance and drift following in the wake. The suggestion from sequence-based analyses of a Pleistocene extinction of a substantial part of North Africa and a Pleistocene/Holocene eastward re-colonisation of western North Africa from the Canaries remains possible.

Pronounced Fixation, Strong Population Differentiation and Complex Population History in the Canary Islands Blue Tit Subspecies Complex

PubMed Central

Hansson, Bengt; Ljungqvist, Marcus; Illera, Juan-Carlos; Kvist, Laura

2014-01-01

Evolutionary molecular studies of island radiations may lead to insights in the role of vicariance, founder events, population size and drift in the processes of population differentiation. We evaluate the degree of population genetic differentiation and fixation of the Canary Islands blue tit subspecies complex using microsatellite markers and aim to get insights in the population history using coalescence based methods. The Canary Island populations were strongly genetically differentiated and had reduced diversity with pronounced fixation including many private alleles. In population structure models, the relationship between the central island populations (La Gomera, Tenerife and Gran Canaria) and El Hierro was difficult to disentangle whereas the two European populations showed consistent clustering, the two eastern islands (Fuerteventura and Lanzarote) and Morocco weak clustering, and La Palma a consistent unique lineage. Coalescence based models suggested that the European mainland forms an outgroup to the Afrocanarian population, a split between the western island group (La Palma and El Hierro) and the central island group, and recent splits between the three central islands, and between the two eastern islands and Morocco, respectively. It is clear that strong genetic drift and low level of concurrent gene flow among populations have shaped complex allelic patterns of fixation and skewed frequencies over the archipelago. However, understanding the population history remains challenging; in particular, the pattern of extreme divergence with low genetic diversity and yet unique genetic material in the Canary Island system requires an explanation. A potential scenario is population contractions of a historically large and genetically variable Afrocanarian population, with vicariance and drift following in the wake. The suggestion from sequence-based analyses of a Pleistocene extinction of a substantial part of North Africa and a Pleistocene/Holocene eastward re-colonisation of western North Africa from the Canaries remains possible. PMID:24587269

Evaluating sampling designs by computer simulation: A case study with the Missouri bladderpod

USGS Publications Warehouse

Morrison, L.W.; Smith, D.R.; Young, C.; Nichols, D.W.

2008-01-01

To effectively manage rare populations, accurate monitoring data are critical. Yet many monitoring programs are initiated without careful consideration of whether chosen sampling designs will provide accurate estimates of population parameters. Obtaining accurate estimates is especially difficult when natural variability is high, or limited budgets determine that only a small fraction of the population can be sampled. The Missouri bladderpod, Lesquerella filiformis Rollins, is a federally threatened winter annual that has an aggregated distribution pattern and exhibits dramatic interannual population fluctuations. Using the simulation program SAMPLE, we evaluated five candidate sampling designs appropriate for rare populations, based on 4 years of field data: (1) simple random sampling, (2) adaptive simple random sampling, (3) grid-based systematic sampling, (4) adaptive grid-based systematic sampling, and (5) GIS-based adaptive sampling. We compared the designs based on the precision of density estimates for fixed sample size, cost, and distance traveled. Sampling fraction and cost were the most important factors determining precision of density estimates, and relative design performance changed across the range of sampling fractions. Adaptive designs did not provide uniformly more precise estimates than conventional designs, in part because the spatial distribution of L. filiformis was relatively widespread within the study site. Adaptive designs tended to perform better as sampling fraction increased and when sampling costs, particularly distance traveled, were taken into account. The rate that units occupied by L. filiformis were encountered was higher for adaptive than for conventional designs. Overall, grid-based systematic designs were more efficient and practically implemented than the others. ?? 2008 The Society of Population Ecology and Springer.

Coupling Financial Incentives With Direct Mail in Population-Based Practice.

PubMed

Slater, Jonathan S; Parks, Michael J; Malone, Michael E; Henly, George A; Nelson, Christina L

2017-02-01

Financial incentives are being used increasingly to encourage a wide array of health behaviors because of their well-established efficacy. However, little is known about how to translate incentive-based strategies to public health practice geared toward improving population-level health, and a dearth of research exists on how individuals respond to incentives through public health communication strategies such as direct mail. This study reports results of a population-based randomized controlled trial testing a direct mail, incentive-based intervention for promoting mammography uptake. The study population was composed of a random sample of Minnesota women enrolled in Medicare fee-for-service and overdue for breast cancer screening. Participants ( N = 18,939) were randomized into three groups: (1) Direct Mail only, (2) Direct Mail plus Incentive, and (3) Control. Both direct mail groups received two mailers with a message about the importance of mammography; however, Mail plus Incentive mailers also offered a $25 incentive for getting a mammogram. Logistic regression analyses measured intervention effects. Results showed the odds for receiving mammography were significantly higher for the Direct Mail plus Incentive group compared with both Direct Mail only and Control groups. The use of incentives also proved to be cost-effective. Additionally, the Direct Mail only group was more likely to receive mammography than the Control group. Findings offer experimental evidence on how the population-based strategy of direct mail coupled with a financial incentive can encourage healthy behavior, as well as how incentive-based programs can be translated into health promotion practice aimed at achieving population-level impact.

The priority group index: a proposed new method incorporating high risk and population burden to identify target populations for public health interventions.

PubMed

Zhang, Bo; Cohen, Joanna E; OʼConnor, Shawn

2014-01-01

Selection of priority groups is important for health interventions. However, no quantitative method has been developed. To develop a quantitative method to support the process of selecting priority groups for public health interventions based on both high risk and population health burden. Secondary data analysis of the 2010 Canadian Community Health Survey. Canadian population. Survey respondents. We identified priority groups for 3 diseases: heart disease, stroke, and chronic lower respiratory diseases. Three measures--prevalence, population counts, and adjusted odds ratios (OR)--were calculated for subpopulations (sociodemographic characteristics and other risk factors). A Priority Group Index (PGI) was calculated by summing the rank scores of these 3 measures. Of the 30 priority groups identified by the PGI (10 for each of the 3 disease outcomes), 7 were identified on the basis of high prevalence only, 5 based on population count only, 3 based on high OR only, and the remainder based on combinations of these. The identified priority groups were all in line with the literature as risk factors for the 3 diseases, such as elderly people for heart disease and stroke and those with low income for chronic lower respiratory diseases. The PGI was thus able to balance both high risk and population burden approaches in selecting priority groups, and thus it would address health inequities as well as disease burden in the overall population. The PGI is a quantitative method to select priority groups for public health interventions; it has the potential to enhance the effective use of limited public resources.

Genomic estimation of additive and dominance effects and impact of accounting for dominance on accuracy of genomic evaluation in sheep populations.

PubMed

Moghaddar, N; van der Werf, J H J

2017-12-01

The objectives of this study were to estimate the additive and dominance variance component of several weight and ultrasound scanned body composition traits in purebred and combined cross-bred sheep populations based on single nucleotide polymorphism (SNP) marker genotypes and then to investigate the effect of fitting additive and dominance effects on accuracy of genomic evaluation. Additive and dominance variance components were estimated in a mixed model equation based on "average information restricted maximum likelihood" using additive and dominance (co)variances between animals calculated from 48,599 SNP marker genotypes. Genomic prediction was based on genomic best linear unbiased prediction (GBLUP), and the accuracy of prediction was assessed based on a random 10-fold cross-validation. Across different weight and scanned body composition traits, dominance variance ranged from 0.0% to 7.3% of the phenotypic variance in the purebred population and from 7.1% to 19.2% in the combined cross-bred population. In the combined cross-bred population, the range of dominance variance decreased to 3.1% and 9.9% after accounting for heterosis effects. Accounting for dominance effects significantly improved the likelihood of the fitting model in the combined cross-bred population. This study showed a substantial dominance genetic variance for weight and ultrasound scanned body composition traits particularly in cross-bred population; however, improvement in the accuracy of genomic breeding values was small and statistically not significant. Dominance variance estimates in combined cross-bred population could be overestimated if heterosis is not fitted in the model. © 2017 Blackwell Verlag GmbH.

Does Marital Status Predict the Odds of Suicidal Death in Taiwan? A Seven-Year Population-Based Study

ERIC Educational Resources Information Center

Yeh, Jui-Yuan; Xirasagar, Sudha; Liu, Tsai-Ching; Li, Chong-Yi; Lin, Herng-Ching

2008-01-01

Using nationwide, 7-year population-based data for 1997-2003, we examined marital status to see if it predicted suicide among the ethnic Chinese population of Taiwan. Using cause of death data, with a case-control design, two groups--total adult suicide deaths, n = 17,850, the study group, and adult deaths other than suicide, n = 71,400 (randomly…

Invitation strategies and coverage in the population-based cancer screening programmes in the European Union.

PubMed

Vale, Diama B; Anttila, Ahti; Ponti, Antonio; Senore, Carlo; Sankaranaryanan, Rengaswamy; Ronco, Guglielmo; Segnan, Nereo; Tomatis, Mariano; Žakelj, Maja P; Elfström, Klara M; Lönnberg, Stefan; Dillner, Joakim; Basu, Partha

2018-03-21

The aim of this study was to describe the compliance of the population-based cancer screening programmes in the European Union Member States to the invitation strategies enumerated in the European Guidelines and the impact of such strategies on the invitational coverage. Experts in screening programme monitoring from the respective countries provided data. Coverage by invitation was calculated as the proportion of individuals in the target age range receiving a screening invitation over the total number of annualized eligible population. The invitation strategies of 30 breasts, 25 cervical and 27 colorectal national or regional population-based screening programmes are described. Individual mail invitations are sent by 28 breasts, 20 cervical and 25 colorectal screening programmes. Faecal occult blood test kits are sent by post in 17 of the colorectal cancer screening programmes. The majority of programmes claimed to have a population registry, although some use health insurance data as the database for sending invitations. At least 95% invitation coverage was reached by 16 breast, six cervical and five colorectal screening programmes. Majority of the programmes comply with the invitation strategies enumerated in the European guidelines, although there is still scope for improvements. Coverage by invitation is below the desirable level in many population-based cancer screening programmes in European Union.

The Case for Diabetes Population Health Improvement: Evidence-Based Programming for Population Outcomes in Diabetes

PubMed Central

Maruthur, Nisa; Mathioudakis, Nestoras; Spanakis, Elias; Rubin, Daniel; Zilbermint, Mihail; Hill-Briggs, Felicia

2017-01-01

Purpose of Review The goal of this review is to describe diabetes within a population health improvement framework and to review the evidence for a diabetes population health continuum of intervention approaches, including diabetes prevention and chronic and acute diabetes management, to improve clinical and economic outcomes. Recent Findings Recent studies have shown that compared to usual care, lifestyle interventions in prediabetes lower diabetes risk at the population-level and that group-based programs have low incremental medial cost effectiveness ratio for health systems. Effective outpatient interventions that improve diabetes control and process outcomes are multi-level, targeting the patient, provider, and healthcare system simultaneously and integrate community health workers as a liaison between the patient and community-based healthcare resources. A multi-faceted approach to diabetes management is also effective in the inpatient setting. Interventions shown to promote safe and effective glycemic control and use of evidence-based glucose management practices include provider reminder and clinical decision support systems, automated computer order entry, provider education, and organizational change. Summary Future studies should examine the cost-effectiveness of multi-faceted outpatient and inpatient diabetes management programs to determine the best financial models for incorporating them into diabetes population health strategies. PMID:28567711

Sources of health insurance and characteristics of the uninsured: analysis of the March 2007 Current Population Survey.

PubMed

Fronstin, Paul

2007-10-01

This Issue Brief provides historic data through 2006 on the number and percentage of nonelderly individuals with and without health insurance. Based on EBRI estimates from the U.S. Census Bureau's March 2007 Current Population Survey (CPS), it reflects 2006 data. It also discusses trends in coverage for the 1994-2006 period and highlights characteristics that typically indicate whether an individual is insured. HEALTH COVERAGE CONTINUES DECLINE: The percentage of the nonelderly population (under age 65) with health insurance coverage continued to decline, reaching to a post-1994 low of 82.1 percent in 2006. Declines in health insurance coverage have been recorded in all but four years since 1994, when 36.5 million nonelderly individuals were uninsured; in 2006, the uninsured population was 46.5 million. EMPLOYMENT-BASED COVERAGE REMAINS DOMINANT SOURCE OF HEALTH COVERAGE: Employment-based health benefits remain by far the most common form of health coverage in the United States, consistently covering 60-70 percent of nonelderly individuals. In 2006, 62.2 percent of the nonelderly population had employment-based health benefits, as compared with 64.4 percent in 1994. Between 1994 and 2000, the percentage of the nonelderly population with employment-based coverage expanded. Since 2000, the percentage has declined. PUBLIC PROGRAM COVERAGE IS STABLE: Public-sector health coverage was slightly lower as a percentage of the population in 2006, accounting for 17.5 percent of the nonelderly population. The decline was due to a drop in the percentage of the population covered by the Tricare/CHAMPVA program. Enrollment in Medicaid and the State Children's Health Insurance Program increased, reaching 34.9 million in 2006, and covering 13.4 percent of the nonelderly population, which is significantly above the 10.5 percent level of 1999, but not far above the 12.7 percent level of 1994. INDIVIDUAL COVERAGE STABLE: Individually purchased health coverage was unchanged in 2006 and has basically hovered in the high 6 and low 7 percent range since 1994. PRIVATE- VS. PUBLIC-COVERAGE TRENDS REVERSING: Health insurance coverage generally has not sustained unbroken trends since 1994. There were crosscurrents: Employment-based coverage expanded significantly in the 1994-2000 period to exceed the growth in public programs. Subsequently, the dynamic reversed, as public programs expanded while employment-based coverage declined. It appears that 2005 might be the beginning of a new trend, where the erosion in employment-based coverage is not being offset by expansions in public programs. This may be due to the fact that, while unemployment is relatively low, the cost of providing health benefits continues to increase faster than inflation.

Learning experiences in population education: proposed guidelines and core messages.

PubMed

1984-01-01

As a result of the 1984 Regional Workshop for the Development of Packages of Adequate Learning Requirements in Population Education, the participants tackled the problem of non-institutionalization of population education into the formal and non-formal educational curricula in their countries. Based on their deliberations, several sets of guidelines and core messages were formulated to provide countries with a more definite direction that will hopefully ensure the functional and effective integration of population education in their respective national school and out-of-school curriculum system. Useful packages of learning materials in population education should help realize the country's population policy and goals within the broader framework of socioeconomic development, and the content of the package should comprehensively cover the core messages of the country's Population Information, Education and Communication (IEC) Program. The population knowledge base of the package should be accurate and relevant; the package should provide for graphic and visual presentation and for assessment of effects on the target groups. Proposed core messages in population education discuss the advantages of small family size and delayed marriage, and aspects of responsible parenthood. Other messages discuss population resource development and population-related beliefs and values.

[Comparative study of the population structure and population assignment of sockeye salmon Oncorhynchus nerka from West Kamchatka based on RAPD-PCR and microsatellite polymorphism].

PubMed

Zelenina, D A; Khrustaleva, A M; Volkov, A A

2006-05-01

Using two types of molecular markers, a comparative analysis of the population structure of sockeye salmon from West Kamchatka as well as population assignment of each individual fish were carried out. The values of a RAPD-PCR-based population assignment test (94-100%) were somewhat higher than those based on microsatellite data (74-84%). However, these results seem quite satisfactory because of high polymorphism of the microsatellite loci examined. The UPGMA dendrograms of genetic similarity of three largest spawning populations, constructed using each of the methods, were highly reliable, which was demonstrated by high bootstrap indices (100% in the case of RAPD-PCR; 84 and 100%, in the case of microsatellite analysis), though the resultant trees differed from one another. The different topology of the trees, in our view, is explained by the fact that the employed methods explored different parts of the genome; hence, the obtained results, albeit valid, may not correlate. Thus, to enhance reliability of the results, several methods of analysis should be used concurrently.

Population-based contracting (population health): part II.

PubMed

Jacofsky, D J

2017-11-01

Modern healthcare contracting is shifting the responsibility for improving quality, enhancing community health and controlling the total cost of care for patient populations from payers to providers. Population-based contracting involves capitated risk taken across an entire population, such that any included services within the contract are paid for by the risk-bearing entity throughout the term of the agreement. Under such contracts, a risk-bearing entity, which may be a provider group, a hospital or another payer, administers the contract and assumes risk for contractually defined services. These contracts can be structured in various ways, from professional fee capitation to full global per member per month diagnosis-based risk. The entity contracting with the payer must have downstream network contracts to provide the care and facilities that it has agreed to provide. Population health is a very powerful model to reduce waste and costs. It requires a deep understanding of the nuances of such contracting and the appropriate infrastructure to manage both networks and risk. Cite this article: Bone Joint J 2017;99-B:1431-4. ©2017 The British Editorial Society of Bone & Joint Surgery.

Current CRISPR gene drive systems are likely to be highly invasive in wild populations.

PubMed

Noble, Charleston; Adlam, Ben; Church, George M; Esvelt, Kevin M; Nowak, Martin A

2018-06-19

Recent reports have suggested that self-propagating CRISPR-based gene drive systems are unlikely to efficiently invade wild populations due to drive-resistant alleles that prevent cutting. Here we develop mathematical models based on existing empirical data to explicitly test this assumption for population alteration drives. Our models show that although resistance prevents spread to fixation in large populations, even the least effective drive systems reported to date are likely to be highly invasive. Releasing a small number of organisms will often cause invasion of the local population, followed by invasion of additional populations connected by very low rates of gene flow. Hence, initiating contained field trials as tentatively endorsed by the National Academies report on gene drive could potentially result in unintended spread to additional populations. Our mathematical results suggest that self-propagating gene drive is best suited to applications such as malaria prevention that seek to affect all wild populations of the target species. © 2018, Noble et al.

Epidemiological evidence for a health risk from mobile phone base stations.

PubMed

Khurana, Vini G; Hardell, Lennart; Everaert, Joris; Bortkiewicz, Alicja; Carlberg, Michael; Ahonen, Mikko

2010-01-01

Human populations are increasingly exposed to microwave/radiofrequency (RF) emissions from wireless communication technology, including mobile phones and their base stations. By searching PubMed, we identified a total of 10 epidemiological studies that assessed for putative health effects of mobile phone base stations. Seven of these studies explored the association between base station proximity and neurobehavioral effects and three investigated cancer. We found that eight of the 10 studies reported increased prevalence of adverse neurobehavioral symptoms or cancer in populations living at distances < 500 meters from base stations. None of the studies reported exposure above accepted international guidelines, suggesting that current guidelines may be inadequate in protecting the health of human populations. We believe that comprehensive epidemiological studies of long-term mobile phone base station exposure are urgently required to more definitively understand its health impact.

Creating a stage-based deterministic PVA model - the western prairie fringed orchid [Exercise 12

Treesearch

Carolyn Hull Sieg; Rudy M. King; Fred Van Dyke

2003-01-01

Contemporary efforts to conserve populations and species often employ population viability analysis (PVA), a specific application of population modeling that estimates the effects of environmental and demographic processes on population growth rates. These models can also be used to estimate probabilities that a population will fall below a certain level. This...

47 CFR 90.685 - Authorization, construction and implementation of EA licenses.

Code of Federal Regulations, 2014 CFR

2014-10-01

... into operation a sufficient number of base stations to provide coverage to at least one-third of the population of its EA-based service area. Further, each EA licensee must provide coverage to at least two-thirds of the population of the EA-based service area within five years of the grant of their initial...

47 CFR 90.685 - Authorization, construction and implementation of EA licenses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... into operation a sufficient number of base stations to provide coverage to at least one-third of the population of its EA-based service area. Further, each EA licensee must provide coverage to at least two-thirds of the population of the EA-based service area within five years of the grant of their initial...

47 CFR 90.685 - Authorization, construction and implementation of EA licenses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... into operation a sufficient number of base stations to provide coverage to at least one-third of the population of its EA-based service area. Further, each EA licensee must provide coverage to at least two-thirds of the population of the EA-based service area within five years of the grant of their initial...

47 CFR 90.685 - Authorization, construction and implementation of EA licenses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... into operation a sufficient number of base stations to provide coverage to at least one-third of the population of its EA-based service area. Further, each EA licensee must provide coverage to at least two-thirds of the population of the EA-based service area within five years of the grant of their initial...

47 CFR 90.685 - Authorization, construction and implementation of EA licenses.

Code of Federal Regulations, 2013 CFR

2013-10-01

... into operation a sufficient number of base stations to provide coverage to at least one-third of the population of its EA-based service area. Further, each EA licensee must provide coverage to at least two-thirds of the population of the EA-based service area within five years of the grant of their initial...

Evidence-Based Practice in Mental Health Care to Ethnic Minority Communities: Has Its Practice Fallen Short of Its Evidence?

ERIC Educational Resources Information Center

Aisenberg, Eugene

2008-01-01

Evidence-based practice (EBP) has contributed substantially to the advancement of knowledge in the treatment and prevention of adult mental health disorders. A fundamental assumption, based on documented evidence of effectiveness with certain populations, is that EBP is equally effective and applicable to all populations. However, small sample…

Monitoring Dolphins in an Urban Marine System: Total and Effective Population Size Estimates of Indo-Pacific Bottlenose Dolphins in Moreton Bay, Australia

PubMed Central

Ansmann, Ina C.; Lanyon, Janet M.; Seddon, Jennifer M.; Parra, Guido J.

2013-01-01

Moreton Bay, Queensland, Australia is an area of high biodiversity and conservation value and home to two sympatric sub-populations of Indo-Pacific bottlenose dolphins (Tursiops aduncus). These dolphins live in close proximity to major urban developments. Successful management requires information regarding their abundance. Here, we estimate total and effective population sizes of bottlenose dolphins in Moreton Bay using photo-identification and genetic data collected during boat-based surveys in 2008–2010. Abundance (N) was estimated using open population mark-recapture models based on sighting histories of distinctive individuals. Effective population size (Ne) was estimated using the linkage disequilibrium method based on nuclear genetic data at 20 microsatellite markers in skin samples, and corrected for bias caused by overlapping generations (Nec). A total of 174 sightings of dolphin groups were recorded and 365 different individuals identified. Over the whole of Moreton Bay, a population size N of 554±22.2 (SE) (95% CI: 510–598) was estimated. The southern bay sub-population was small at an estimated N = 193±6.4 (SE) (95% CI: 181–207), while the North sub-population was more numerous, with 446±56 (SE) (95% CI: 336–556) individuals. The small estimated effective population size of the southern sub-population (Nec = 56, 95% CI: 33–128) raises conservation concerns. A power analysis suggested that to reliably detect small (5%) declines in size of this population would require substantial survey effort (>4 years of annual mark-recapture surveys) at the precision levels achieved here. To ensure that ecological as well as genetic diversity within this population of bottlenose dolphins is preserved, we consider that North and South sub-populations should be treated as separate management units. Systematic surveys over smaller areas holding locally-adapted sub-populations are suggested as an alternative method for increasing ability to detect abundance trends. PMID:23755197

Population-based respiratory 4D motion atlas construction and its application for VR simulations of liver punctures

NASA Astrophysics Data System (ADS)

Mastmeyer, Andre; Wilms, Matthias; Handels, Heinz

2018-03-01

Virtual reality (VR) training simulators of liver needle insertion in the hepatic area of breathing virtual patients often need 4D image data acquisitions as a prerequisite. Here, first a population-based breathing virtual patient 4D atlas is built and second the requirement of a dose-relevant or expensive acquisition of a 4D CT or MRI data set for a new patient can be mitigated by warping the mean atlas motion. The breakthrough contribution of this work is the construction and reuse of population-based, learned 4D motion models.

The impact of US versus Indian BMD reference standards on the diagnosis of osteoporosis among South Asian Indians living in the United States

PubMed Central

Melamed, Alexander; Vittinghoff, Eric; Sriram, Usha; Schwartz, Ann V.; Kanaya, Alka M.

2010-01-01

The relationship between bone mineral density (BMD) and fracture risk is not well-established for non-white populations. There is no established BMD reference standard for South Asians. Dual energy x-ray absorptiometry (DXA) was used to measure BMD at total hip and lumbar spine in 150 US-based South Asian Indians. For each subject T-scores were calculated using BMD reference values based on US white, North Indian and South Indian populations, and the resulting WHO BMD category assignments were compared. Reference standards derived from Indian populations classified a larger proportion of US-based Indians as normal than did US white-based standards. The percentage of individuals reclassified when changing between reference standards varied by skeletal site and reference population origin, ranging from 13% (95% CI, 7–18%), when switching from US-white- to North Indian-based standard for total hip, to 40% (95% CI, 32–48%), when switching from US white to South Indian reference values for lumbar spine. These finding illustrate that choice of reference standard has a significant effect on the diagnosis of osteoporosis in South Asians, and underscore the importance of future research to quantify the relationship between BMD and fracture risk in this population. PMID:20663699

Regional differences in echocardiography provision in New Zealand--results from the 2013 SCANZ Workforce Survey.

PubMed

Buckley, Belinda A; Poppe, Katrina; Farnworth, Mark J; Whalley, Gillian

2015-01-30

Abstract Healthcare may be unevenly distributed based on geographic location. This study aimed to identify whether regional differences in echocardiography provision exist and, if so, to explore key causes. In March 2013, 18 public hospitals with a sonographer-led echocardiography service were surveyed, all of which provided data. Questions related to characteristics of the sonographer workforce, echocardiogram volumes and workflows. Information on District Health Board (DHB) population was obtained from public access websites. Multivariable linear regression was performed using the following variables: ethnicity, age, socioeconomic status, type of centre, sonographer full-time equivalent (FTE) and number/proportion of trainees to determine their potential contribution to echocardiogram volume. 1748 echocardiograms were performed per 100,000 population (mean) with significant differences seen amongst DHBs but not between tertiary surgical and regional centres (surgical median 1802, regional median 1658, p=0.18). Regional disparity in the population-based cardiac sonographer workforce size was observed and the number of scans performed per sonographer was higher in larger centres. In multivariable modelling, the DHB population-based scan volume was predicted by: socioeconomic status (top two quintiles of deprivation status increased scans by 75 per 100,000 population, p=0.02) and age (age 20 to 65 years increased scans by 131 per 100,000 population, p=0.06). Regional differences in echocardiography services in New Zealand exist as evidenced by marked regional disparity in both population-based echo volumes and cardiac sonographer workforce size.

Population genetic analysis of Enterocytozoon bieneusi in humans.

PubMed

Li, Wei; Cama, Vitaliano; Feng, Yaoyu; Gilman, Robert H; Bern, Caryn; Zhang, Xichen; Xiao, Lihua

2012-01-01

Genotyping based on sequence analysis of the ribosomal internal transcribed spacer has revealed significant genetic diversity in Enterocytozoonbieneusi. Thus far, the population genetics of E. bieneusi and its significance in the epidemiology of microsporidiosis have not been examined. In this study, a multilocus sequence typing of E. bieneusi in AIDS patients in Lima, Peru was conducted, using 72 specimens previously genotyped as A, D, IV, EbpC, WL11, Peru7, Peru8, Peru10 and Peru11 at the internal transcribed spacer locus. Altogether, 39 multilocus genotypes were identified among the 72 specimens. The observation of strong intragenic linkage disequilibria and limited genetic recombination among markers were indicative of an overall clonal population structure of E. bieneusi. Measures of pair-wise intergenic linkage disequilibria and a standardised index of association (IAS) based on allelic profile data further supported this conclusion. Both sequence-based and allelic profile-based phylogenetic analyses showed the presence of two genetically isolated groups in the study population, one (group 1) containing isolates of the anthroponotic internal transcribed spacer genotype A, and the other (group 2) containing isolates of multiple internal transcribed spacer genotypes (mainly genotypes D and IV) with zoonotic potential. The measurement of linkage disequilibria and recombination indicated group 2 had a clonal population structure, whereas group 1 had an epidemic population structure. The formation of the two sub-populations was confirmed by STRUCTURE and Wright's fixation index (FST) analyses. The data highlight the power of MLST in understanding the epidemiology of E. bieneusi. Published by Elsevier Ltd.

Research progress of plant population genomics based on high-throughput sequencing.

PubMed

Wang, Yun-sheng

2016-08-01

Population genomics, a new paradigm for population genetics, combine the concepts and techniques of genomics with the theoretical system of population genetics and improve our understanding of microevolution through identification of site-specific effect and genome-wide effects using genome-wide polymorphic sites genotypeing. With the appearance and improvement of the next generation high-throughput sequencing technology, the numbers of plant species with complete genome sequences increased rapidly and large scale resequencing has also been carried out in recent years. Parallel sequencing has also been done in some plant species without complete genome sequences. These studies have greatly promoted the development of population genomics and deepened our understanding of the genetic diversity, level of linking disequilibium, selection effect, demographical history and molecular mechanism of complex traits of relevant plant population at a genomic level. In this review, I briely introduced the concept and research methods of population genomics and summarized the research progress of plant population genomics based on high-throughput sequencing. I also discussed the prospect as well as existing problems of plant population genomics in order to provide references for related studies.

Genetic structure of cougar populations across the Wyoming basin: Metapopulation or megapopulation

USGS Publications Warehouse

Anderson, C.R.; Lindzey, F.G.; McDonald, D.B.

2004-01-01

We examined the genetic structure of 5 Wyoming cougar (Puma concolor) populations surrounding the Wyoming Basin, as well as a population from southwestern Colorado. When using 9 microsatellite DNA loci, observed heterozygosity was similar among populations (HO = 0.49-0.59) and intermediate to that of other large carnivores. Estimates of genetic structure (FST = 0.028, RST = 0.029) and number of migrants per generation (Nm) suggested high gene flow. Nm was lowest between distant populations and highest among adjacent populations. Examination of these data, plus Mantel test results of genetic versus geographic distance (P ??? 0.01), suggested both isolation by distance and an effect of habitat matrix. Bayesian assignment to population based on individual genotypes showed that cougars in this region were best described as a single panmictic population. Total effective population size for cougars in this region ranged from 1,797 to 4,532 depending on mutation model and analytical method used. Based on measures of gene flow, extinction risk in the near future appears low. We found no support for the existence of metapopulation structure among cougars in this region.

A Markov chain model for studying suicide dynamics: an illustration of the Rose theorem

PubMed Central

2014-01-01

Background High-risk strategies would only have a modest effect on suicide prevention within a population. It is best to incorporate both high-risk and population-based strategies to prevent suicide. This study aims to compare the effectiveness of suicide prevention between high-risk and population-based strategies. Methods A Markov chain illness and death model is proposed to determine suicide dynamic in a population and examine its effectiveness for reducing the number of suicides by modifying certain parameters of the model. Assuming a population with replacement, the suicide risk of the population was estimated by determining the final state of the Markov model. Results The model shows that targeting the whole population for suicide prevention is more effective than reducing risk in the high-risk tail of the distribution of psychological distress (i.e. the mentally ill). Conclusions The results of this model reinforce the essence of the Rose theorem that lowering the suicidal risk in the population at large may be more effective than reducing the high risk in a small population. PMID:24948330

Anal sex practices in heterosexual and male homosexual populations: a review of population-based data.

PubMed

Heywood, Wendy; Smith, Anthony M A

2012-12-01

Anal sex is known to be an important risk factor for anal cancer. Yet compared with vaginal intercourse, little is known about anal sex practices in either heterosexual or male homosexual populations. Of the data that are available, it appears a significant and increasing minority of heterosexuals have ever practised anal intercourse. Among homosexual men, most, but not all, report anal sex, with large proportions of men engaging in both insertive and receptive anal intercourse. The most significant finding of the review was the dearth of population-based data, particularly relating to homosexual men.

The Italian Hub of Population Biobanks as a Potential Tool for Improving Public Health Stewardship

PubMed Central

Napolitano, Mariarosaria; Santoro, Filippo; Belardelli, Filippo; Federici, Antonio

2013-01-01

In Italy, a country that is experiencing the decentralization of health services from central to regional level of government, the Minister of Health is proposing stewardship as a model of governance for the public health system. Stewardship favors efficiency in the policy decision-making process, based on reciprocal trust, and tends to be more ethical. The embryonic proposal to test stewardship in the field of population-based research was advanced during the launching conference Challenges and Opportunities of the Italian Hub of Population Biobanks (HIBP) held in 2012 in Rome. Resources collected by population biobanks (i.e., blood and its derivatives, and/or DNA isolated from any type of biological samples and relative associated data) have, in fact, a recognized scientific value for the investigation of links between genetics, health and life style, and epidemiological outcomes through population biobank-based studies, and are essential to planning effective and qualified interventions for public health. The current economic crisis requires a strong push to rationalize investment in health policies. In particular, population biobank-based studies require financial commitment, often of long duration, for the realization of their goals. Thus, innovative solutions to allow fast integration of scientific knowledge into political health strategy are required. During the conference in Rome, it was proposed to test the stewardship model by its application to the inter-relationship between population biobank-based studies and disease prevention. Stewardship minimizes barriers to innovation and uses information more effectively to better develop new strategies for prevention and/or treatment. In the months following the conference, the proposal was defined more clearly, and the HIBP network became a potential tool for testing and implementing this model in the Italian Public Health prevention system. PMID:23840926

Improving population management through pharmacist-primary care integration: a pilot study.

PubMed

Kennedy, Amanda G; Chen, Harry; Corriveau, Michele; MacLean, Charles D

2015-02-01

Pharmacists have unique skills that may benefit primary care practices. The objective of this demonstration project was to determine the impact of integrating pharmacists into patient-centered medical homes, with a focus on population management. Pharmacists were partnered into 5 primary care practices in Vermont 1 day per week to provide direct patient care, population-based medication management, and prescriber education. The main measures included a description of drug therapy problems identified and cost avoidance models. The pharmacists identified 708 drug therapy problems through direct patient care (336/708; 47.5%), population-based strategies (276/708; 38.9%), and education (96/708; 13.6%). Common population-based strategies included adjusting doses and discontinuing unnecessary medications. Pharmacists' recommendations to correct drug therapy problems were accepted by prescribers 86% of the time, when data about acceptance were known. Of the 49 recommendations not accepted, 47/49 (96%) were population-based and 2/49 (4%) were related to direct patient care. The cost avoidance model suggests $2.11 in cost was avoided for every $1.00 spent on a pharmacist ($373,092/$176,690). There was clear value in integrating pharmacists into primary care teams. Their inclusion prevented adverse drug events, avoided costs, and improved patient outcomes. Primary care providers should consider pharmacists well suited to offer direct patient care, population-based management, and prescriber education to their practices. To be successful, pharmacists must have full permission to document findings in the primary care practices' electronic health records. Given that many pharmacist services do not involve billable activities, sustainability requires identifying alternative funding mechanisms that do not rely on a traditional fee-for-service approach.

Population Research.

ERIC Educational Resources Information Center

National Inst. of Child Health and Human Development (NIH), Bethesda, MD.

The scope of population research as carried on by the National Institute of Child Health and Human Development (NICHD) is set forth in this booklet. Population problems of the world, United States, and the individual are considered along with international population policies based on voluntary family planning programs. NICHD goals for biological…

CRISPR/Cas9 gene drives in genetically variable and nonrandomly mating wild populations

PubMed Central

Drury, Douglas W.; Dapper, Amy L.; Siniard, Dylan J.; Zentner, Gabriel E.; Wade, Michael J.

2017-01-01

Synthetic gene drives based on CRISPR/Cas9 have the potential to control, alter, or suppress populations of crop pests and disease vectors, but it is unclear how they will function in wild populations. Using genetic data from four populations of the flour beetle Tribolium castaneum, we show that most populations harbor genetic variants in Cas9 target sites, some of which would render them immune to drive (ITD). We show that even a rare ITD allele can reduce or eliminate the efficacy of a CRISPR/Cas9-based synthetic gene drive. This effect is equivalent to and accentuated by mild inbreeding, which is a characteristic of many disease-vectoring arthropods. We conclude that designing such drives will require characterization of genetic variability and the mating system within and among targeted populations. PMID:28560324

CRISPR/Cas9 gene drives in genetically variable and nonrandomly mating wild populations.

PubMed

Drury, Douglas W; Dapper, Amy L; Siniard, Dylan J; Zentner, Gabriel E; Wade, Michael J

2017-05-01

Synthetic gene drives based on CRISPR/Cas9 have the potential to control, alter, or suppress populations of crop pests and disease vectors, but it is unclear how they will function in wild populations. Using genetic data from four populations of the flour beetle Tribolium castaneum , we show that most populations harbor genetic variants in Cas9 target sites, some of which would render them immune to drive (ITD). We show that even a rare ITD allele can reduce or eliminate the efficacy of a CRISPR/Cas9-based synthetic gene drive. This effect is equivalent to and accentuated by mild inbreeding, which is a characteristic of many disease-vectoring arthropods. We conclude that designing such drives will require characterization of genetic variability and the mating system within and among targeted populations.

Prevalence of non-traumatic spinal cord injury in Victoria, Australia.

PubMed

New, P W; Farry, A; Baxter, D; Noonan, V K

2013-02-01

Forecasting using population modelling. To determine the prevalence of non-traumatic spinal cord injury (NTSCI) on 30 June 2010. Victoria, Australia. Modelling used the following data: incidence of NTSCI based on state-wide, population-based, health-administration database of hospital admissions; state and national population profiles and life tables; levels of NTSCI based on national rehabilitation outcomes data; and life expectancy for persons with SCI. The total population prevalence rate was 367.2 per million, whereas the prevalence in adults aged 16 years and older was estimated to be 2027, equivalent to a population prevalence rate of 455 per million persons. There were more males (1097) with NTSCI (prevalence rate males 197.8 per million population; females 169.1 per million population) and the prevalence was much higher among those with paraplegia (prevalence rate 269.3 per million compared to 97.8 per million with tetraplegia) and incomplete NTSCI. Ventilator dependency (prevalence rate 1.6 per million population) and paediatric NTSCI (prevalence rate 6 per million population ≤ 15 years old) were extremely rare. We have reported a method for calculating an estimate of the prevalence of NTSCI that provides information that will be vital to optimise health care planning for this group of highly disabled members of society. It is suggested that refinements to the modelling methods are required to enhance its reliability. Future projects should be directed at refining the mortality ratios and performing cohort survival studies.

Genome-wide analysis of signatures of selection in populations of African honey bees (Apis mellifera) using new web-based tools.

PubMed

Fuller, Zachary L; Niño, Elina L; Patch, Harland M; Bedoya-Reina, Oscar C; Baumgarten, Tracey; Muli, Elliud; Mumoki, Fiona; Ratan, Aakrosh; McGraw, John; Frazier, Maryann; Masiga, Daniel; Schuster, Stephen; Grozinger, Christina M; Miller, Webb

2015-07-10

With the development of inexpensive, high-throughput sequencing technologies, it has become feasible to examine questions related to population genetics and molecular evolution of non-model species in their ecological contexts on a genome-wide scale. Here, we employed a newly developed suite of integrated, web-based programs to examine population dynamics and signatures of selection across the genome using several well-established tests, including F ST, pN/pS, and McDonald-Kreitman. We applied these techniques to study populations of honey bees (Apis mellifera) in East Africa. In Kenya, there are several described A. mellifera subspecies, which are thought to be localized to distinct ecological regions. We performed whole genome sequencing of 11 worker honey bees from apiaries distributed throughout Kenya and identified 3.6 million putative single-nucleotide polymorphisms. The dense coverage allowed us to apply several computational procedures to study population structure and the evolutionary relationships among the populations, and to detect signs of adaptive evolution across the genome. While there is considerable gene flow among the sampled populations, there are clear distinctions between populations from the northern desert region and those from the temperate, savannah region. We identified several genes showing population genetic patterns consistent with positive selection within African bee populations, and between these populations and European A. mellifera or Asian Apis florea. These results lay the groundwork for future studies of adaptive ecological evolution in honey bees, and demonstrate the use of new, freely available web-based tools and workflows ( http://usegalaxy.org/r/kenyanbee ) that can be applied to any model system with genomic information.

A general modeling framework for describing spatially structured population dynamics

USGS Publications Warehouse

Sample, Christine; Fryxell, John; Bieri, Joanna; Federico, Paula; Earl, Julia; Wiederholt, Ruscena; Mattsson, Brady; Flockhart, Tyler; Nicol, Sam; Diffendorfer, James E.; Thogmartin, Wayne E.; Erickson, Richard A.; Norris, D. Ryan

2017-01-01

Variation in movement across time and space fundamentally shapes the abundance and distribution of populations. Although a variety of approaches model structured population dynamics, they are limited to specific types of spatially structured populations and lack a unifying framework. Here, we propose a unified network-based framework sufficiently novel in its flexibility to capture a wide variety of spatiotemporal processes including metapopulations and a range of migratory patterns. It can accommodate different kinds of age structures, forms of population growth, dispersal, nomadism and migration, and alternative life-history strategies. Our objective was to link three general elements common to all spatially structured populations (space, time and movement) under a single mathematical framework. To do this, we adopt a network modeling approach. The spatial structure of a population is represented by a weighted and directed network. Each node and each edge has a set of attributes which vary through time. The dynamics of our network-based population is modeled with discrete time steps. Using both theoretical and real-world examples, we show how common elements recur across species with disparate movement strategies and how they can be combined under a unified mathematical framework. We illustrate how metapopulations, various migratory patterns, and nomadism can be represented with this modeling approach. We also apply our network-based framework to four organisms spanning a wide range of life histories, movement patterns, and carrying capacities. General computer code to implement our framework is provided, which can be applied to almost any spatially structured population. This framework contributes to our theoretical understanding of population dynamics and has practical management applications, including understanding the impact of perturbations on population size, distribution, and movement patterns. By working within a common framework, there is less chance that comparative analyses are colored by model details rather than general principles

Paternal genetic affinity between Western Austronesians and Daic populations.

PubMed

Li, Hui; Wen, Bo; Chen, Shu-Juo; Su, Bing; Pramoonjago, Patcharin; Liu, Yangfan; Pan, Shangling; Qin, Zhendong; Liu, Wenhong; Cheng, Xu; Yang, Ningning; Li, Xin; Tran, Dinhbinh; Lu, Daru; Hsu, Mu-Tsu; Deka, Ranjan; Marzuki, Sangkot; Tan, Chia-Chen; Jin, Li

2008-05-15

Austronesian is a linguistic family spread in most areas of the Southeast Asia, the Pacific Ocean, and the Indian Ocean. Based on their linguistic similarity, this linguistic family included Malayo-Polynesians and Taiwan aborigines. The linguistic similarity also led to the controversial hypothesis that Taiwan is the homeland of all the Malayo-Polynesians, a hypothesis that has been debated by ethnologists, linguists, archaeologists, and geneticists. It is well accepted that the Eastern Austronesians (Micronesians and Polynesians) derived from the Western Austronesians (Island Southeast Asians and Taiwanese), and that the Daic populations on the mainland are supposed to be the headstream of all the Austronesian populations. In this report, we studied 20 SNPs and 7 STRs in the non-recombining region of the 1,509 Y chromosomes from 30 China Daic populations, 23 Indonesian and Vietnam Malayo-Polynesian populations, and 11 Taiwan aboriginal populations. These three groups show many resemblances in paternal lineages. Admixture analyses demonstrated that the Daic populations are hardly influenced by Han Chinese genetically, and that they make up the largest proportion of Indonesians. Most of the population samples contain a high frequency of haplogroup O1a-M119, which is nearly absent in other ethnic families. The STR network of haplogroup O1a* illustrated that Indonesian lineages did not derive from Taiwan aborigines as linguistic studies suggest, but from Daic populations. We show that, in contrast to the Taiwan homeland hypothesis, the Island Southeast Asians do not have a Taiwan origin based on their paternal lineages. Furthermore, we show that both Taiwan aborigines and Indonesians likely derived from the Daic populations based on their paternal lineages. These two populations seem to have evolved independently of each other. Our results indicate that a super-phylum, which includes Taiwan aborigines, Daic, and Malayo-Polynesians, is genetically educible.

Genetic variation and forensic characteristic analysis of 25 STRs of a novel fluorescence co-amplification system in Chinese Southern Shaanxi Han population

PubMed Central

Liu, Yao-Shun; Chen, Jian-Gang; Mei, Ting; Guo, Yu-Xin; Meng, Hao-Tian; Li, Jian-Fei; Wei, Yuan-Yuan; Jin, Xiao-Ye; Zhu, Bo-Feng; Zhang, Li-Ping

2017-01-01

We analyzed the genetic polymorphisms of 15 autosomal and 10 Y-chromosomal STR loci in 214 individuals of Han population from Southern Shaanxi of China and studied the genetic relationships between Southern Shaanxi Han and other populations. We observed a total of 150 alleles at 15 autosomal STR loci with the corresponding allelic frequencies ranging from 0.0023 to 0.5210, and the combined power of discrimination and exclusion for the 15 autosomal STR loci were 0.99999999999999998866 and 0.999998491, respectively. For the 10 Y-STR loci, totally 100 different haplotypes were obtained, of which 94 were unique. The discriminatory capacity and haplotype diversity values of the 10 Y-STR loci were 0.9259 and 0.998269, respectively. The results demonstrated high genetic diversities of the 25 STR loci in the population for forensic applications. We constructed neighbor-joining tree and conducted principal component analysis based on 15 autosomal STR loci and conducted multidimensional scaling analysis and constructed neighbor-joining tree based on 10 Y-STR loci. The results of population genetic analyses based on both autosomal and Y-chromosome STRs indicated that the studied Southern Shaanxi Han population had relatively closer genetic relationship with Eastern Han population, and distant relationships with Croatian, Serbian and Moroccan populations. PMID:28903432

Polar bear aerial survey in the eastern Chukchi Sea: A pilot study

USGS Publications Warehouse

Evans, Thomas J.; Fischbach, Anthony S.; Schliebe, Scott L.; Manly, Bryan; Kalxdorff, Susanne B.; York, Geoff S.

2003-01-01

Alaska has two polar bear populations: the Southern Beaufort Sea population, shared with Canada, and the Chukchi/Bering Seas population, shared with Russia. Currently a reliable population estimate for the Chukchi/Bering Seas population does not exist. Land-based aerial and mark-recapture population surveys may not be possible in the Chukchi Sea because variable ice conditions, the limited range of helicopters, extremely large polar bear home ranges, and severe weather conditions may limit access to remote areas. Thus line-transect aerial surveys from icebreakers may be the best available tool to monitor this polar bear stock. In August 2000, a line-transect survey was conducted in the eastern Chukchi Sea and western Beaufort Sea from helicopters based on a U.S. Coast Guard icebreaker under the "Ship of Opportunity" program. The objectives of this pilot study were to estimate polar bear density in the eastern Chukchi and western Beaufort Seas and to assess the logistical feasibility of using ship-based aerial surveys to develop polar bear population estimates. Twenty-nine polar bears in 25 groups were sighted on 94 transects (8257 km). The density of bears was estimated as 1 bear per 147 km² (CV = 38%). Additional aerial surveys in late fall, using dedicated icebreakers, would be required to achieve the number of sightings, survey effort, coverage, and precision needed for more effective monitoring of population trends in the Chukchi Sea.

A model for identifying and ranking need for trauma service in nonmetropolitan regions based on injury risk and access to services.

PubMed

Schuurman, Nadine; Bell, Nathaniel; Hameed, Morad S; Simons, Richard

2008-07-01

Timely access to definitive trauma care has been shown to improve survival rates after severe injury. Unfortunately, despite development of sophisticated trauma systems, prompt, definitive trauma care remains unavailable to over 50 million North Americans, particularly in rural areas. Measures to quantify social and geographic isolation may provide important insights for the development of health policy aimed at reducing the burden of injury and improving access to trauma care in presently under serviced populations. Indices of social deprivation based on census data, and spatial analyses of access to trauma centers based on street network files were combined into a single index, the Population Isolation Vulnerability Amplifier (PIVA) to characterize vulnerability to trauma in socioeconomically and geographically diverse rural and urban communities across British Columbia. Regions with a sufficient core population that are more than one hour travel time from existing services were ranked based on their level of socioeconomic vulnerability. Ten regions throughout the province were identified as most in need of trauma services based on population, isolation and vulnerability. Likewise, 10 communities were classified as some of the least isolated areas and were simultaneously classified as least vulnerable populations in province. The model was verified using trauma services utilization data from the British Columbia Trauma Registry. These data indicate that including vulnerability in the model provided superior results to running the model based only on population and road travel time. Using the PIVA model we have shown that across Census Urban Areas there are wide variations in population dependence on and distances to accredited tertiary/district trauma centers throughout British Columbia. Many of the factors that influence access to definitive trauma care can be combined into a single quantifiable model that researchers in the health sector can use to predict where to place new services. The model can also be used to locate optimal locations for any basket of health services.

Educational Attainment in the United States: 2003. Population Characteristics. Current Population Reports. P20-550

ERIC Educational Resources Information Center

Stoops, Nicole

2004-01-01

This report provides information on basic educational trends and attainment levels across many segments of the population. The findings are based on data collected in the 2003 Annual Social and Economic Supplement (ASEC) to the Current Population Survey (CPS) and refer to the population 25 years and over unless otherwise specified. The population…

Violence Reported by the Immigrant Population Is High as Compared with the Native Population in Southeast Spain

ERIC Educational Resources Information Center

Colorado-Yohar, S.; Tormo, M. J.; Salmeron, D.; Dios, S.; Ballesta, M.; Navarro, C.

2012-01-01

Immigrants constitute a population vulnerable to the problem of violence. This study sought to ascertain the prevalence of violence reported by the immigrant population in the Murcian Region of Spain and characterize the related factors, taking the country population as reference. A cross-sectional study was carried out based on a representative…

42 CFR 414.410 - Phased-in implementation of competitive bidding programs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... largest MSAs by total population based on 2009 population estimates, and not already phased in as of June 1, 2008). CMS may subdivide any of the 91 MSAs with a population of greater than 8,000,000 into... population of less than 250,000. (iii) An area with low population density within an MSA not selected under...

42 CFR 414.410 - Phased-in implementation of competitive bidding programs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... largest MSAs by total population based on 2009 population estimates, and not already phased in as of June 1, 2008). CMS may subdivide any of the 91 MSAs with a population of greater than 8,000,000 into... population of less than 250,000. (iii) An area with low population density within an MSA not selected under...

42 CFR 414.410 - Phased-in implementation of competitive bidding programs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... largest MSAs by total population based on 2009 population estimates, and not already phased in as of June 1, 2008). CMS may subdivide any of the 91 MSAs with a population of greater than 8,000,000 into... population of less than 250,000. (iii) An area with low population density within an MSA not selected under...

Characteristics of the Low-Income Population, 1971. Current Population Reports: Consumer Income, Series P-60, Number 86.

ERIC Educational Resources Information Center

Shelburne, Elizabeth C.

This report presents social and economic statistics for the population of the United States below the low-income level in 1971, based on the March 1972 Current Population Survey. Included are data on selected characteristics of the population below the low-income level in 1971, such as geographic distribution, race and ethnic origin, family…

The Black Population in the United States: March 1992.

ERIC Educational Resources Information Center

Bennett, Claudette E.

1993-01-01

This report presents a statistical portrait of the demographic, social, and economic characteristics of the black population in the United States that is based primarily on the March 1992 Supplement to the Current Population Survey. Topics covered include: population growth; marital status; family type and distribution; the living arrangements of…

Implications Climate Change for Contaminant Management: Effects of Temperature on Individual and population toxicity in Daphnia Magna

EPA Science Inventory

A main goal of ecotoxicology and risk assessment is to assess the impact on aquatic populations. However the most widely used bioassays measure the response of individuals to infer population effects. Bridging the gap between established individual-based methodology and the popul...

42 CFR 505.5 - Loan criteria.

Code of Federal Regulations, 2011 CFR

2011-10-01

... meet the following criteria: (1) The hospital is located in a State that, based on population density, is defined as a rural State. A rural State is one of ten States with the lowest population density... prioritized beginning with the State with the lowest population density. Population density is determined...

42 CFR 505.5 - Loan criteria.

Code of Federal Regulations, 2012 CFR

2012-10-01

... that meet the following criteria: (1) The hospital is located in a State that, based on population density, is defined as a rural State. A rural State is one of ten States with the lowest population... prioritized beginning with the State with the lowest population density. Population density is determined...

42 CFR 505.5 - Loan criteria.

Code of Federal Regulations, 2013 CFR

2013-10-01

... that meet the following criteria: (1) The hospital is located in a State that, based on population density, is defined as a rural State. A rural State is one of ten States with the lowest population... prioritized beginning with the State with the lowest population density. Population density is determined...

42 CFR 505.5 - Loan criteria.

Code of Federal Regulations, 2014 CFR

2014-10-01

... that meet the following criteria: (1) The hospital is located in a State that, based on population density, is defined as a rural State. A rural State is one of ten States with the lowest population... prioritized beginning with the State with the lowest population density. Population density is determined...

42 CFR 505.5 - Loan criteria.

Code of Federal Regulations, 2010 CFR

2010-10-01

... meet the following criteria: (1) The hospital is located in a State that, based on population density, is defined as a rural State. A rural State is one of ten States with the lowest population density... prioritized beginning with the State with the lowest population density. Population density is determined...

The evolution of human mobility based on the public goods game

NASA Astrophysics Data System (ADS)

Yan, Shiqing

2017-07-01

We explore the evolution of human mobility behavior based on public goods game. By using mean field method, the population distribution in different regions is theoretical calculated. Numerical simulation results show that the correlation between the region's degree and its final population is not significant under a larger human migration rate. Human mobility could effectively promote cooperative behavior and the population balance of different regions. Therefore, encouraging individuals to migrate may increase the total benefits of the whole society. Moreover, increasing the cooperation cost could reduce the number of cooperators, and that would happen to the correlation between the region's degree and its final population. The results indicate the total population could not dramatically rise with the region's degree under an unfair society.

1996-based national population projections for the United Kingdom and constituent countries.

PubMed

Shaw, C

1998-01-01

The 1996-based national population projections, carried out by the Government Actuary in consultation with the Registrars General, show the population of the United Kingdom rising from 58.8 million in 1996 to over 62 million by 2021. The population will become gradually older with the mean age expected to rise from 38.4 years in 1996 to nearly 42 years by 2021. The number of children aged under 16 is projected to fall by 1.0 million (9 per cent) by 2021, while the number aged 65 and over is projected to increase by 2.7 million (29 per cent). Longer-term projections suggest the population will peak around 2031 and then gradually start to fall.

Including trait-based early warning signals helps predict population collapse

PubMed Central

Clements, Christopher F.; Ozgul, Arpat

2016-01-01

Foreseeing population collapse is an on-going target in ecology, and this has led to the development of early warning signals based on expected changes in leading indicators before a bifurcation. Such signals have been sought for in abundance time-series data on a population of interest, with varying degrees of success. Here we move beyond these established methods by including parallel time-series data of abundance and fitness-related trait dynamics. Using data from a microcosm experiment, we show that including information on the dynamics of phenotypic traits such as body size into composite early warning indices can produce more accurate inferences of whether a population is approaching a critical transition than using abundance time-series alone. By including fitness-related trait information alongside traditional abundance-based early warning signals in a single metric of risk, our generalizable approach provides a powerful new way to assess what populations may be on the verge of collapse. PMID:27009968

Genetic diversity based on 28S rDNA sequences among populations of Culex quinquefasciatus collected at different locations in Tamil Nadu, India.

PubMed

Sakthivelkumar, S; Ramaraj, P; Veeramani, V; Janarthanan, S

2015-09-01

The basis of the present study was to distinguish the existence of any genetic variability among populations of Culex quinquefasciatus which would be a valuable tool in the management of mosquito control programmes. In the present study, population of Cx. quinquefasciatus collected at different locations in Tamil Nadu were analyzed for their genetic variation based on 28S rDNA D2 region nucleotide sequences. A high degree of genetic polymorphism was detected in the sequences of D2 region of 28S rDNA on the predicted secondary structures in spite of high nucleotide sequence similarity. The findings based on secondary structure using rDNA sequences suggested the existence of a complex genotypic diversity of Cx. quinquefasciatus population collected at different locations of Tamil Nadu, India. This complexity in genetic diversity in a single mosquito population collected at different locations is considered an important issue towards their influence and nature of vector potential of these mosquitoes.

Population-based surveillance for bacterial meningitis in China, September 2006-December 2009.

PubMed

Li, Yixing; Yin, Zundong; Shao, Zhujun; Li, Manshi; Liang, Xiaofeng; Sandhu, Hardeep S; Hadler, Stephen C; Li, Junhong; Sun, Yinqi; Li, Jing; Zou, Wenjing; Lin, Mei; Zuo, Shuyan; Mayer, Leonard W; Novak, Ryan T; Zhu, Bingqing; Xu, Li; Luo, Huiming

2014-01-01

During September 2006-December 2009, we conducted active population and sentinel laboratory-based surveillance for bacterial meningitis pathogens, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b, in 4 China prefectures. We identified 7,876 acute meningitis and encephalitis syndrome cases, including 6,388 among prefecture residents. A total of 833 resident cases from sentinel hospitals met the World Health Organization case definition for probable bacterial meningitis; 339 of these cases were among children <5 years of age. Laboratory testing confirmed bacterial meningitis in 74 of 3,391 tested cases. The estimated annual incidence (per 100,000 population) of probable bacterial meningitis ranged from 1.84 to 2.93 for the entire population and from 6.95 to 22.30 for children <5 years old. Active surveillance with laboratory confirmation has provided a population-based estimate of the number of probable bacterial meningitis cases in China, but more complete laboratory testing is needed to better define the epidemiology of the disease in this country.

Mourning dove hunting regulation strategy based on annual harvest statistics and banding data

USGS Publications Warehouse

Otis, D.L.

2006-01-01

Although managers should strive to base game bird harvest management strategies on mechanistic population models, monitoring programs required to build and continuously update these models may not be in place. Alternatively, If estimates of total harvest and harvest rates are available, then population estimates derived from these harvest data can serve as the basis for making hunting regulation decisions based on population growth rates derived from these estimates. I present a statistically rigorous approach for regulation decision-making using a hypothesis-testing framework and an assumed framework of 3 hunting regulation alternatives. I illustrate and evaluate the technique with historical data on the mid-continent mallard (Anas platyrhynchos) population. I evaluate the statistical properties of the hypothesis-testing framework using the best available data on mourning doves (Zenaida macroura). I use these results to discuss practical implementation of the technique as an interim harvest strategy for mourning doves until reliable mechanistic population models and associated monitoring programs are developed.

Evolution of kin recognition mechanisms in a fish.

PubMed

Hain, Timothy J A; Garner, Shawn R; Ramnarine, Indar W; Neff, Bryan D

2017-03-01

Both selection and phylogenetic history can influence the evolution of phenotypic traits. Here we used recently characterized variation in kin recognition mechanisms among six guppy populations to explore the phylogenetic history of this trait. Guppies can use two different kin recognition mechanisms: either phenotype matching, in which individuals are identified based on comparison with a recognition template, or familiarity, in which individuals are remembered based on previous interactions. Across the six populations, we identified four transitions in recognition mechanism: phenotype matching evolved once and was subsequently lost in a single population, whereas familiarity evolved twice. Based on a molecular clock, these transitions occurred among populations that had diverged on a timescale of hundreds of thousands of years, which is two orders of magnitude faster than previously documented transitions in recognition mechanisms. A randomization test provided no evidence that recognition mechanisms were constrained by phylogeny, suggesting that recognition mechanisms have the capacity to evolve rapidly, although the specific selection pressures that may be contributing to variation in recognition mechanisms across populations remain unknown.

Population-based Surveillance for Bacterial Meningitis in China, September 2006–December 2009

PubMed Central

Li, Yixing; Yin, Zundong; Shao, Zhujun; Li, Manshi; Liang, Xiaofeng; Sandhu, Hardeep S.; Hadler, Stephen C.; Li, Junhong; Sun, Yinqi; Li, Jing; Zou, Wenjing; Lin, Mei; Zuo, Shuyan; Mayer, Leonard W.; Novak, Ryan T.; Zhu, Bingqing; Xu, Li

2014-01-01

During September 2006–December 2009, we conducted active population and sentinel laboratory–based surveillance for bacterial meningitis pathogens, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b, in 4 China prefectures. We identified 7,876 acute meningitis and encephalitis syndrome cases, including 6,388 among prefecture residents. A total of 833 resident cases from sentinel hospitals met the World Health Organization case definition for probable bacterial meningitis; 339 of these cases were among children <5 years of age. Laboratory testing confirmed bacterial meningitis in 74 of 3,391 tested cases. The estimated annual incidence (per 100,000 population) of probable bacterial meningitis ranged from 1.84 to 2.93 for the entire population and from 6.95 to 22.30 for children <5 years old. Active surveillance with laboratory confirmation has provided a population-based estimate of the number of probable bacterial meningitis cases in China, but more complete laboratory testing is needed to better define the epidemiology of the disease in this country. PMID:24377388

Assessment of TREM2 rs75932628 association with Alzheimer's disease in a population-based sample: the Cache County Study.

PubMed

Gonzalez Murcia, Josue D; Schmutz, Cameron; Munger, Caitlin; Perkes, Ammon; Gustin, Aaron; Peterson, Michael; Ebbert, Mark T W; Norton, Maria C; Tschanz, Joann T; Munger, Ronald G; Corcoran, Christopher D; Kauwe, John S K

2013-12-01

Recent studies have identified the rs75932628 (R47H) variant in TREM2 as an Alzheimer's disease risk factor with estimated odds ratio ranging from 2.9 to 5.1. The Cache County Memory Study is a large, population-based sample designed for the study of memory and aging. We genotyped R47H in 2974 samples (427 cases and 2540 control subjects) from the Cache County study using a custom TaqMan assay. We observed 7 heterozygous cases and 12 heterozygous control subjects with an odds ratio of 3.5 (95% confidence interval, 1.3-8.8; p = 0.0076). The minor allele frequency and population attributable fraction for R47H were 0.0029 and 0.004, respectively. This study replicates the association between R47H and Alzheimer's disease risk in a large, population-based sample, and estimates the population frequency and attributable risk of this rare variant. Copyright © 2013 Elsevier Inc. All rights reserved.

The use of customised versus population-based birthweight standards in predicting perinatal mortality.

PubMed

Zhang, X; Platt, R W; Cnattingius, S; Joseph, K S; Kramer, M S

2007-04-01

The objective of this study was to critically examine potential artifacts and biases underlying the use of 'customised' standards of birthweight for gestational age (GA). Population-based cohort study. Sweden. A total of 782,303 singletons > or =28 weeks of gestation born in 1992-2001 to Nordic mothers with complete data on birthweight; GA; and maternal age, parity, height, and pre-pregnancy weight. We compared perinatal mortality in four groups of infants based on the following classification of small for gestational age (SGA): non-SGA based on either population-based or customised standards (the reference group), SGA based on the population-based standard only, SGA based on the customised standard only, and SGA according to both standards. We used graphical methods to compare GA-specific birthweight cutoffs for SGA using the two standards and also used logistic regression to control for differences in GA and maternal pre-pregnancy body mass index (BMI) in the four groups. Perinatal mortality, including stillbirth and neonatal death. Customisation led to a large artifactual increase in the proportion of SGA infants born preterm. Adjustment for differences in GA and maternal BMI markedly reduced the excess risk among infants classified as SGA by customised standards only. The large increase in perinatal mortality risk among infants classified as SGA based on customised standards is largely an artifact due to inclusion of more preterm births.

A bootstrap based space-time surveillance model with an application to crime occurrences

NASA Astrophysics Data System (ADS)

Kim, Youngho; O'Kelly, Morton

2008-06-01

This study proposes a bootstrap-based space-time surveillance model. Designed to find emerging hotspots in near-real time, the bootstrap based model is characterized by its use of past occurrence information and bootstrap permutations. Many existing space-time surveillance methods, using population at risk data to generate expected values, have resulting hotspots bounded by administrative area units and are of limited use for near-real time applications because of the population data needed. However, this study generates expected values for local hotspots from past occurrences rather than population at risk. Also, bootstrap permutations of previous occurrences are used for significant tests. Consequently, the bootstrap-based model, without the requirement of population at risk data, (1) is free from administrative area restriction, (2) enables more frequent surveillance for continuously updated registry database, and (3) is readily applicable to criminology and epidemiology surveillance. The bootstrap-based model performs better for space-time surveillance than the space-time scan statistic. This is shown by means of simulations and an application to residential crime occurrences in Columbus, OH, year 2000.

Detection of sea otters in boat-based surveys of Prince William Sound, Alaska. Marine mammal study 6-19. Exxon Valdez oil spill state/federal natural resource damage assessment final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Udevitz, M.S.; Bodkin, J.L.; Costa, D.P.

1995-05-01

Boat-based surveys were used to monitor the Prince William Sound sea otter population before and after the Exxon Valdez oil spill. Population and loss estimates could be obtained from these surveys by direct expansion from the counts in the surveyed transects under the assumption that all otters in those transects were observed. The authors conducted a pilot study using ground-based observers in conjunction with the August 1990 survey of marine mammals and birds to investigate the validity of this assumption. The proportion of otters detected by boat crews was estimated by comparing boat and ground-based observations on 22 segments ofmore » shoreline transects. Overall, the authors estimated that only 70% of the otters in surveyed shoreline transects were detected by the boat crews. These results suggest that unadjusted expansions of boat survey transect counts will underestimate sea otter population size and that loss estimates based on comparisons of unadjusted population estimates will be biased.« less

Predictors of Word-Reading Ability in 7-Year-Olds: Analysis of Data from a U.K. Cohort Study

ERIC Educational Resources Information Center

Russell, Ginny; Ukoumunne, Obioha C.; Ryder, Denise; Golding, Jean; Norwich, Brahm

2018-01-01

Previous U.K. population-based studies have found associations amongst early speech and language difficulties, socioeconomic disadvantage and children's word-reading ability later on. We examine the strength of these associations in a recent U.K. population-based birth cohort. Analyses were based on 13,680 participants. Linear regression models…

Exploring the persistence of stream-dwelling trout populations under alternative real-world turbidity regimes with an individual-based model

Treesearch

Bret C. Harvey; Steven F. Railsback

2009-01-01

We explored the effects of elevated turbidity on stream-resident populations of coastal cutthroat trout Oncorhynchus clarkii clarkii using a spatially explicit individual-based model. Turbidity regimes were contrasted by means of 15-year simulations in a third-order stream in northwestern California. The alternative regimes were based on multiple-year, continuous...

Prevalence and Incidence of Systemic Lupus Erythematosus in a Population-Based Registry of American Indian and Alaska Native People, 2007–2009

PubMed Central

Ferucci, Elizabeth D.; Johnston, Janet M.; Gaddy, Jasmine R.; Sumner, Lisa; Posever, James O.; Choromanski, Tammy L.; Gordon, Caroline; Lim, S. Sam; Helmick, Charles G.

2015-01-01

Objective Few studies have investigated the epidemiology of systemic lupus erythematosus (SLE) in American Indian and Alaska Native populations. The objective of this study was to determine the prevalence and incidence of SLE in the Indian Health Service (IHS) active clinical population in 3 regions of the US. Methods For this population-based registry within the IHS, the denominator consisted of individuals in the IHS active clinical population in 2007, 2008, and/or 2009 and residing in a community in 1 of 3 specified regions. Potential SLE cases were identified based on the presence of a diagnostic code for SLE or related disorder in the IHS National Data Warehouse. Detailed medical record abstraction was performed for each potential case. The primary case definition was documentation in the medical record of ≥4 of the revised American College of Rheumatology criteria for the classification of SLE. Prevalence was calculated for 2007, and the mean annual incidence was calculated for the years 2007 through 2009. Results The age-adjusted prevalence and incidence of SLE according to the primary definition were 178 per 100,000 person-years (95% confidence interval [95% CI] 157–200) and 7.4 per 100,000 person-years (95% CI 5.1–10.4). Among women, the age-adjusted prevalence was 271, and the age-adjusted incidence was 10.4. The prevalence was highest in women ages 50–59 years and in the Phoenix Area IHS. Conclusion The first population-based lupus registry in the US American Indian and Alaska Native population has demonstrated that the prevalence and incidence of SLE are high. Our estimates are as high as or higher than the rates reported in the US black population. PMID:24891315

Clinical reasoning and population health: decision making for an emerging paradigm of health care.

PubMed

Edwards, Ian; Richardson, Barbara

2008-01-01

Chronic conditions now provide the major disease and disability burden facing humanity. This development has necessitated a reorientation in the practice skills of health care professions away from hospital-based inpatient and outpatient care toward community-based management of patients with chronic conditions. Part of this reorientation toward community-based management of chronic conditions involves practitioners' understanding and adoption of a concept of population health management based on appropriate theoretical models of health care. Drawing on recent studies of expertise in physiotherapy, this article proposes a clinical reasoning and decision-making framework to meet these challenges. The challenge of population and community-based management of chronic conditions also provides an opportunity for physiotherapists to further clarify a professional epistemology of practice that embraces the kinds of knowledge and clinical reasoning processes used in physiotherapy practice. Three case studies related to the management of chronic musculoskeletal pain in different populations are used to exemplify the range of epistemological perspectives that underpin community-based practice. They illustrate the link between conceptualizations of practice problems and knowledge sources that are used as a basis for clinical reasoning and decision making as practitioners are increasingly required to move between the clinic and the community.

Numeric, Agent-based or System Dynamics Model? Which Modeling Approach is the Best for Vast Population Simulation?

PubMed

Cimler, Richard; Tomaskova, Hana; Kuhnova, Jitka; Dolezal, Ondrej; Pscheidl, Pavel; Kuca, Kamil

2018-01-01

Alzheimer's disease is one of the most common mental illnesses. It is posited that more than 25% of the population is affected by some mental disease during their lifetime. Treatment of each patient draws resources from the economy concerned. Therefore, it is important to quantify the potential economic impact. Agent-based, system dynamics and numerical approaches to dynamic modeling of the population of the European Union and its patients with Alzheimer's disease are presented in this article. Simulations, their characteristics, and the results from different modeling tools are compared. The results of these approaches are compared with EU population growth predictions from the statistical office of the EU by Eurostat. The methodology of a creation of the models is described and all three modeling approaches are compared. The suitability of each modeling approach for the population modeling is discussed. In this case study, all three approaches gave us the results corresponding with the EU population prediction. Moreover, we were able to predict the number of patients with AD and, based on the modeling method, we were also able to monitor different characteristics of the population. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Maintenance of algal endosymbionts in Paramecium bursaria: a simple model based on population dynamics.

PubMed

Iwai, Sosuke; Fujiwara, Kenji; Tamura, Takuro

2016-09-01

Algal endosymbiosis is widely distributed in eukaryotes including many protists and metazoans, and plays important roles in aquatic ecosystems, combining phagotrophy and phototrophy. To maintain a stable symbiotic relationship, endosymbiont population size in the host must be properly regulated and maintained at a constant level; however, the mechanisms underlying the maintenance of algal endosymbionts are still largely unknown. Here we investigate the population dynamics of the unicellular ciliate Paramecium bursaria and its Chlorella-like algal endosymbiont under various experimental conditions in a simple culture system. Our results suggest that endosymbiont population size in P. bursaria was not regulated by active processes such as cell division coupling between the two organisms, or partitioning of the endosymbionts at host cell division. Regardless, endosymbiont population size was eventually adjusted to a nearly constant level once cells were grown with light and nutrients. To explain this apparent regulation of population size, we propose a simple mechanism based on the different growth properties (specifically the nutrient requirements) of the two organisms, and based from this develop a mathematical model to describe the population dynamics of host and endosymbiont. The proposed mechanism and model may provide a basis for understanding the maintenance of algal endosymbionts. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Accounting for imperfect detection is critical for inferring marine turtle nesting population trends.

PubMed

Pfaller, Joseph B; Bjorndal, Karen A; Chaloupka, Milani; Williams, Kristina L; Frick, Michael G; Bolten, Alan B

2013-01-01

Assessments of population trends based on time-series counts of individuals are complicated by imperfect detection, which can lead to serious misinterpretations of data. Population trends of threatened marine turtles worldwide are usually based on counts of nests or nesting females. We analyze 39 years of nest-count, female-count, and capture-mark-recapture (CMR) data for nesting loggerhead turtles (Caretta caretta) on Wassaw Island, Georgia, USA. Annual counts of nests and females, not corrected for imperfect detection, yield significant, positive trends in abundance. However, multistate open robust design modeling of CMR data that accounts for changes in imperfect detection reveals that the annual abundance of nesting females has remained essentially constant over the 39-year period. The dichotomy could result from improvements in surveys or increased within-season nest-site fidelity in females, either of which would increase detection probability. For the first time in a marine turtle population, we compare results of population trend analyses that do and do not account for imperfect detection and demonstrate the potential for erroneous conclusions. Past assessments of marine turtle population trends based exclusively on count data should be interpreted with caution and re-evaluated when possible. These concerns apply equally to population assessments of all species with imperfect detection.

Predicting population dynamics from the properties of individuals: a cross-level test of dynamic energy budget theory.

PubMed

Martin, Benjamin T; Jager, Tjalling; Nisbet, Roger M; Preuss, Thomas G; Grimm, Volker

2013-04-01

Individual-based models (IBMs) are increasingly used to link the dynamics of individuals to higher levels of biological organization. Still, many IBMs are data hungry, species specific, and time-consuming to develop and analyze. Many of these issues would be resolved by using general theories of individual dynamics as the basis for IBMs. While such theories have frequently been examined at the individual level, few cross-level tests exist that also try to predict population dynamics. Here we performed a cross-level test of dynamic energy budget (DEB) theory by parameterizing an individual-based model using individual-level data of the water flea, Daphnia magna, and comparing the emerging population dynamics to independent data from population experiments. We found that DEB theory successfully predicted population growth rates and peak densities but failed to capture the decline phase. Further assumptions on food-dependent mortality of juveniles were needed to capture the population dynamics after the initial population peak. The resulting model then predicted, without further calibration, characteristic switches between small- and large-amplitude cycles, which have been observed for Daphnia. We conclude that cross-level tests help detect gaps in current individual-level theories and ultimately will lead to theory development and the establishment of a generic basis for individual-based models and ecology.

Importance of the habitat choice behavior assumed when modeling the effects of food and temperature on fish populations

USGS Publications Warehouse

Wildhaber, Mark L.; Lamberson, Peter J.

2004-01-01

Various mechanisms of habitat choice in fishes based on food and/or temperature have been proposed: optimal foraging for food alone; behavioral thermoregulation for temperature alone; and behavioral energetics and discounted matching for food and temperature combined. Along with development of habitat choice mechanisms, there has been a major push to develop and apply to fish populations individual-based models that incorporate various forms of these mechanisms. However, it is not known how the wide variation in observed and hypothesized mechanisms of fish habitat choice could alter fish population predictions (e.g. growth, size distributions, etc.). We used spatially explicit, individual-based modeling to compare predicted fish populations using different submodels of patch choice behavior under various food and temperature distributions. We compared predicted growth, temperature experience, food consumption, and final spatial distribution using the different models. Our results demonstrated that the habitat choice mechanism assumed in fish population modeling simulations was critical to predictions of fish distribution and growth rates. Hence, resource managers who use modeling results to predict fish population trends should be very aware of and understand the underlying patch choice mechanisms used in their models to assure that those mechanisms correctly represent the fish populations being modeled.

Generalization and dilution of association results from European GWAS in populations of non-European ancestry: the PAGE study.

PubMed

Carlson, Christopher S; Matise, Tara C; North, Kari E; Haiman, Christopher A; Fesinmeyer, Megan D; Buyske, Steven; Schumacher, Fredrick R; Peters, Ulrike; Franceschini, Nora; Ritchie, Marylyn D; Duggan, David J; Spencer, Kylee L; Dumitrescu, Logan; Eaton, Charles B; Thomas, Fridtjof; Young, Alicia; Carty, Cara; Heiss, Gerardo; Le Marchand, Loic; Crawford, Dana C; Hindorff, Lucia A; Kooperberg, Charles L

2013-09-01

The vast majority of genome-wide association study (GWAS) findings reported to date are from populations with European Ancestry (EA), and it is not yet clear how broadly the genetic associations described will generalize to populations of diverse ancestry. The Population Architecture Using Genomics and Epidemiology (PAGE) study is a consortium of multi-ancestry, population-based studies formed with the objective of refining our understanding of the genetic architecture of common traits emerging from GWAS. In the present analysis of five common diseases and traits, including body mass index, type 2 diabetes, and lipid levels, we compare direction and magnitude of effects for GWAS-identified variants in multiple non-EA populations against EA findings. We demonstrate that, in all populations analyzed, a significant majority of GWAS-identified variants have allelic associations in the same direction as in EA, with none showing a statistically significant effect in the opposite direction, after adjustment for multiple testing. However, 25% of tagSNPs identified in EA GWAS have significantly different effect sizes in at least one non-EA population, and these differential effects were most frequent in African Americans where all differential effects were diluted toward the null. We demonstrate that differential LD between tagSNPs and functional variants within populations contributes significantly to dilute effect sizes in this population. Although most variants identified from GWAS in EA populations generalize to all non-EA populations assessed, genetic models derived from GWAS findings in EA may generate spurious results in non-EA populations due to differential effect sizes. Regardless of the origin of the differential effects, caution should be exercised in applying any genetic risk prediction model based on tagSNPs outside of the ancestry group in which it was derived. Models based directly on functional variation may generalize more robustly, but the identification of functional variants remains challenging.

Simulated effects of recruitment variability, exploitation, and reduced habitat area on the muskellunge population in Shoepack Lake, Voyageurs National Park, Minnesota

USGS Publications Warehouse

Frohnauer, N.K.; Pierce, C.L.; Kallemeyn, L.W.

2007-01-01

The genetically unique population of muskellunge Esox masquinongy inhabiting Shoepack Lake in Voyageurs National Park, Minnesota, is potentially at risk for loss of genetic variability and long-term viability. Shoepack Lake has been subject to dramatic surface area changes from the construction of an outlet dam by beavers Castor canadensis and its subsequent failure. We simulated the long-term dynamics of this population in response to recruitment variation, increased exploitation, and reduced habitat area. We then estimated the effective population size of the simulated population and evaluated potential threats to long-term viability, based on which we recommend management actions to help preserve the long-term viability of the population. Simulations based on the population size and habitat area at the beginning of a companion study resulted in an effective population size that was generally above the threshold level for risk of loss of genetic variability, except when fishing mortality was increased. Simulations based on the reduced habitat area after the beaver dam failure and our assumption of a proportional reduction in population size resulted in an effective population size that was generally below the threshold level for risk of loss of genetic variability. Our results identified two potential threats to the long-term viability of the Shoepack Lake muskellunge population, reduction in habitat area and exploitation. Increased exploitation can be prevented through traditional fishery management approaches such as the adoption of no-kill, barbless hook, and limited entry regulations. Maintenance of the greatest possible habitat area and prevention of future habitat area reductions will require maintenance of the outlet dam built by beavers. Our study should enhance the long-term viability of the Shoepack Lake muskellunge population and illustrates a useful approach for other unique populations. ?? Copyright by the American Fisheries Society 2007.

Generalization and Dilution of Association Results from European GWAS in Populations of Non-European Ancestry: The PAGE Study

PubMed Central

Carlson, Christopher S.; Matise, Tara C.; North, Kari E.; Haiman, Christopher A.; Fesinmeyer, Megan D.; Buyske, Steven; Schumacher, Fredrick R.; Peters, Ulrike; Franceschini, Nora; Ritchie, Marylyn D.; Duggan, David J.; Spencer, Kylee L.; Dumitrescu, Logan; Eaton, Charles B.; Thomas, Fridtjof; Young, Alicia; Carty, Cara; Heiss, Gerardo; Le Marchand, Loic; Crawford, Dana C.; Hindorff, Lucia A.; Kooperberg, Charles L.

2013-01-01

The vast majority of genome-wide association study (GWAS) findings reported to date are from populations with European Ancestry (EA), and it is not yet clear how broadly the genetic associations described will generalize to populations of diverse ancestry. The Population Architecture Using Genomics and Epidemiology (PAGE) study is a consortium of multi-ancestry, population-based studies formed with the objective of refining our understanding of the genetic architecture of common traits emerging from GWAS. In the present analysis of five common diseases and traits, including body mass index, type 2 diabetes, and lipid levels, we compare direction and magnitude of effects for GWAS-identified variants in multiple non-EA populations against EA findings. We demonstrate that, in all populations analyzed, a significant majority of GWAS-identified variants have allelic associations in the same direction as in EA, with none showing a statistically significant effect in the opposite direction, after adjustment for multiple testing. However, 25% of tagSNPs identified in EA GWAS have significantly different effect sizes in at least one non-EA population, and these differential effects were most frequent in African Americans where all differential effects were diluted toward the null. We demonstrate that differential LD between tagSNPs and functional variants within populations contributes significantly to dilute effect sizes in this population. Although most variants identified from GWAS in EA populations generalize to all non-EA populations assessed, genetic models derived from GWAS findings in EA may generate spurious results in non-EA populations due to differential effect sizes. Regardless of the origin of the differential effects, caution should be exercised in applying any genetic risk prediction model based on tagSNPs outside of the ancestry group in which it was derived. Models based directly on functional variation may generalize more robustly, but the identification of functional variants remains challenging. PMID:24068893

An intelligent case-adjustment algorithm for the automated design of population-based quality auditing protocols.

PubMed

Advani, Aneel; Jones, Neil; Shahar, Yuval; Goldstein, Mary K; Musen, Mark A

2004-01-01

We develop a method and algorithm for deciding the optimal approach to creating quality-auditing protocols for guideline-based clinical performance measures. An important element of the audit protocol design problem is deciding which guide-line elements to audit. Specifically, the problem is how and when to aggregate individual patient case-specific guideline elements into population-based quality measures. The key statistical issue involved is the trade-off between increased reliability with more general population-based quality measures versus increased validity from individually case-adjusted but more restricted measures done at a greater audit cost. Our intelligent algorithm for auditing protocol design is based on hierarchically modeling incrementally case-adjusted quality constraints. We select quality constraints to measure using an optimization criterion based on statistical generalizability coefficients. We present results of the approach from a deployed decision support system for a hypertension guideline.

Comparison between Flow Cytometry and Traditional Culture Methods for Efficacy Assessment of Six Disinfectant Agents against Nosocomial Bacterial Species

PubMed Central

Massicotte, Richard; Mafu, Akier A.; Ahmad, Darakhshan; Deshaies, Francis; Pichette, Gilbert; Belhumeur, Pierre

2017-01-01

The present study was undertaken to compare the use of flow cytometry (FCM) and traditional culture methods for efficacy assessment of six disinfectants used in Quebec hospitals including: two quaternary ammonium-based, two activated hydrogen peroxide-based, one phenol-based, and one sodium hypochlorite-based. Four nosocomial bacterial species, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Vancomycin-resistant Enterococci faecalis, were exposed to minimum lethal concentrations (MLCs) and sublethal concentrations (1/2 MLCs) of disinfectants under study. The results showed a strong correlation between the two techniques for the presence of dead and live cell populations, as well as, evidence of injured populations with the FCM. The only exception was observed with sodium hypochlorite at higher concentrations where fluorescence was diminished and underestimating dead cell population. The results also showed that FCM can replace traditional microbiological methods to study disinfectant efficacy on bacteria. Furthermore, FCM profiles for E. coli and E. faecalis cells exposed to sublethal concentrations exhibited distinct populations of injured cells, opening a new aspect for future research and investigation to elucidate the role of injured, cultural/noncuturable/resuscitable cell populations in infection control. PMID:28217115

Assessment of public health impact of work-related asthma.

PubMed

Jaakkola, Maritta S; Jaakkola, Jouni J K

2012-03-05

Asthma is among the most common chronic diseases in working-aged populations and occupational exposures are important causal agents. Our aims were to evaluate the best methods to assess occurrence, public health impact, and burden to society related to occupational or work-related asthma and to achieve comparable estimates for different populations. We addressed three central questions: 1: What is the best method to assess the occurrence of occupational asthma? We evaluated: 1) assessment of the occurrence of occupational asthma per se, and 2) assessment of adult-onset asthma and the population attributable fractions due to specific occupational exposures. 2: What are the best methods to assess public health impact and burden to society related to occupational or work-related asthma? We evaluated methods based on assessment of excess burden of disease due to specific occupational exposures. 3: How to achieve comparable estimates for different populations? We evaluated comparability of estimates of occurrence and burden attributable to occupational asthma based on different methods. Assessment of the occurrence of occupational asthma per se can be used in countries with good coverage of the identification system for occupational asthma, i.e. countries with well-functioning occupational health services. Assessment based on adult-onset asthma and population attributable fractions due to specific occupational exposures is a good approach to estimate the occurrence of occupational asthma at the population level. For assessment of public health impact from work-related asthma we recommend assessing excess burden of disease due to specific occupational exposures, including excess incidence of asthma complemented by an assessment of disability from it. International comparability of estimates can be best achieved by methods based on population attributable fractions. Public health impact assessment for occupational asthma is central in prevention and health policy planning and could be improved by purposeful development of methods for assessing health benefits from preventive actions. Registry-based methods are suitable for evaluating time-trends of occurrence at a given population but for international comparisons they face serious limitations. Assessment of excess burden of disease due to specific occupational exposure is a useful measure, when there is valid information on population exposure and attributable fractions.

The HIV care cascade: a systematic review of data sources, methodology and comparability.

PubMed

Medland, Nicholas A; McMahon, James H; Chow, Eric P F; Elliott, Julian H; Hoy, Jennifer F; Fairley, Christopher K

2015-01-01

The cascade of HIV diagnosis, care and treatment (HIV care cascade) is increasingly used to direct and evaluate interventions to increase population antiretroviral therapy (ART) coverage, a key component of treatment as prevention. The ability to compare cascades over time, sub-population, jurisdiction or country is important. However, differences in data sources and methodology used to construct the HIV care cascade might limit its comparability and ultimately its utility. Our aim was to review systematically the different methods used to estimate and report the HIV care cascade and their comparability. A search of published and unpublished literature through March 2015 was conducted. Cascades that reported the continuum of care from diagnosis to virological suppression in a demographically definable population were included. Data sources and methods of measurement or estimation were extracted. We defined the most comparable cascade elements as those that directly measured diagnosis or care from a population-based data set. Thirteen reports were included after screening 1631 records. The undiagnosed HIV-infected population was reported in seven cascades, each of which used different data sets and methods and could not be considered to be comparable. All 13 used mandatory HIV diagnosis notification systems to measure the diagnosed population. Population-based data sets, derived from clinical data or mandatory reporting of CD4 cell counts and viral load tests from all individuals, were used in 6 of 12 cascades reporting linkage, 6 of 13 reporting retention, 3 of 11 reporting ART and 6 of 13 cascades reporting virological suppression. Cascades with access to population-based data sets were able to directly measure cascade elements and are therefore comparable over time, place and sub-population. Other data sources and methods are less comparable. To ensure comparability, countries wishing to accurately measure the cascade should utilize complete population-based data sets from clinical data from elements of a centralized healthcare setting, where available, or mandatory CD4 cell count and viral load test result reporting. Additionally, virological suppression should be presented both as percentage of diagnosed and percentage of estimated total HIV-infected population, until methods to calculate the latter have been standardized.

Developing a systems-based framework of the factors influencing dietary and physical activity behaviours in ethnic minority populations living in Europe - a DEDIPAC study.

PubMed

Holdsworth, Michelle; Nicolaou, Mary; Langøien, Lars Jørun; Osei-Kwasi, Hibbah Araba; Chastin, Sebastien F M; Stok, F Marijn; Capranica, Laura; Lien, Nanna; Terragni, Laura; Monsivais, Pablo; Mazzocchi, Mario; Maes, Lea; Roos, Gun; Mejean, Caroline; Powell, Katie; Stronks, Karien

2017-11-07

Some ethnic minority populations have a higher risk of non-communicable diseases than the majority European population. Diet and physical activity behaviours contribute to this risk, shaped by a system of inter-related factors. This study mapped a systems-based framework of the factors influencing dietary and physical activity behaviours in ethnic minority populations living in Europe, to inform research prioritisation and intervention development. A concept mapping approach guided by systems thinking was used: i. Preparation (protocol and terminology); ii. Generating a list of factors influencing dietary and physical activity behaviours in ethnic minority populations living in Europe from evidence (systematic mapping reviews) and 'eminence' (89 participants from 24 academic disciplines via brainstorming, an international symposium and expert review) and; iii. Seeking consensus on structuring, rating and clustering factors, based on how they relate to each other; and iv. Interpreting/utilising the framework for research and interventions. Similar steps were undertaken for frameworks developed for the majority European population. Seven distinct clusters emerged for dietary behaviour (containing 85 factors) and 8 for physical activity behaviours (containing 183 factors). Four clusters were similar across behaviours: Social and cultural environment; Social and material resources; Psychosocial; and Migration context. Similar clusters of factors emerged in the frameworks for diet and physical activity behaviours of the majority European population, except for 'migration context'. The importance of factors across all clusters was acknowledged, but their relative importance differed for ethnic minority populations compared with the majority population. This systems-based framework integrates evidence from both expert opinion and published literature, to map the factors influencing dietary and physical activity behaviours in ethnic minority groups. Our findings illustrate that innovative research and complex interventions need to be developed that are sensitive to the needs of ethnic minority populations. A systems approach that encompasses the complexity of the inter-related factors that drive behaviours may inform a more holistic public health paradigm to more effectively reach ethnic minorities living in Europe, as well as the majority host population.

The Implications of Ecologically Based Assessment for Primary Prevention with Indigenous Youth Populations

PubMed Central

Okamoto, Scott K.; LeCroy, Craig Winston; Tann, Sheila S.; Rayle, Andrea Dixon; Kulis, Stephen; Dustman, Patricia; Berceli, David

2011-01-01

This paper describes a five-stage approach toward conducting an ecologically based assessment with Indigenous youth populations, and the implications of this approach for the development and implementation of culturally grounded prevention interventions. A description of a pilot study funded by the National Institutes of Health/National Institute on Drug Abuse (NIH/NIDA) focused on drug use and American Indian youth is presented as one model for operationalizing ecologically based assessment with Indigenous youth populations, and issues related to translating the pilot study into a prevention intervention are discussed. This paper suggests that ecologically based assessment can serve as a foundation for culturally grounded prevention interventions, promoting the social and ecological validity of those interventions. PMID:16534658

Proactive tobacco treatment and population-level cessation: a pragmatic randomized clinical trial.

PubMed

Fu, Steven S; van Ryn, Michelle; Sherman, Scott E; Burgess, Diana J; Noorbaloochi, Siamak; Clothier, Barbara; Taylor, Brent C; Schlede, Carolyn M; Burke, Randy S; Joseph, Anne M

2014-05-01

Current tobacco use treatment approaches require smokers to request treatment or depend on the provider to initiate smoking cessation care and are therefore reactive. Most smokers do not receive evidence-based treatments for tobacco use that include both behavioral counseling and pharmacotherapy. To assess the effect of a proactive, population-based tobacco cessation care model on use of evidence-based tobacco cessation treatments and on population-level smoking cessation rates (ie, abstinence among all smokers including those who use and do not use treatment) compared with usual care among a diverse population of current smokers. The Veterans Victory Over Tobacco Study, a pragmatic randomized clinical trial involving a population-based registry of current smokers aged 18 to 80 years. A total of 6400 current smokers, identified using the Department of Veterans Affairs (VA) electronic medical record, were randomized prior to contact to evaluate both the reach and effectiveness of the proactive care intervention. Current smokers were randomized to usual care or proactive care. Proactive care combined (1) proactive outreach and (2) offer of choice of smoking cessation services (telephone or in-person). Proactive outreach included mailed invitations followed by telephone outreach to motivate smokers to seek treatment with choice of services. The primary outcome was 6-month prolonged smoking abstinence at 1 year and was assessed by a follow-up survey among all current smokers regardless of interest in quitting or treatment utilization. A total of 5123 participants were included in the primary analysis. The follow-up survey response rate was 66%. The population-level, 6-month prolonged smoking abstinence rate at 1 year was 13.5% for proactive care compared with 10.9% for usual care (P = .02). Logistic regression mixed model analysis showed a significant effect of the proactive care intervention on 6-month prolonged abstinence (odds ratio [OR], 1.27 [95% CI, 1.03-1.57]). In analyses accounting for nonresponse using likelihood-based not-missing-at-random models, the effect of proactive care on 6-month prolonged abstinence persisted (OR, 1.33 [95% CI, 1.17-1.51]). Proactive, population-based tobacco cessation care using proactive outreach to connect smokers to evidence-based telephone or in-person smoking cessation services is effective for increasing long-term population-level cessation rates. clinicaltrials.gov Identifier: NCT00608426.

Understanding the Connection Between Traumatic Brain Injury and Alzheimer’s Disease: A Population Based Medical Record Review Analysis

DTIC Science & Technology

2016-10-01

AWARD NUMBER: W81XWH-15-1-0573 TITLE: Understanding the Connection Between Traumatic Brain Injury and Alzheimer’s Disease: A Population-Based...Sep 2015 - 14 Sep 2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Understanding the Connection Between Traumatic Brain Injury and Alzheimer’s Disease...TERMS Population; epidemiology; dementia; neurocognitive disorders; brain injuries; Parkinsonian disorders 16. SECURITY CLASSIFICATION OF: U 17

Venous Thromboembolism and Cerebrovascular Events in Patients with Giant Cell Arteritis: A Population-Based Retrospective Cohort Study

PubMed Central

Crowson, Cynthia S.; Makol, Ashima; Ytterberg, Steven R.; Saitta, Antonino; Salvarani, Carlo; Matteson, Eric L.; Warrington, Kenneth J.

2016-01-01

Objective To investigate the incidence of venous thromboembolism (VTE) and cerebrovascular events in a community-based incidence cohort of patients with giant cell arteritis (GCA) compared to the general population. Methods A population-based inception cohort of patients with incident GCA between January 1, 1950 and December 31, 2009 in Olmsted County, Minnesota and a cohort of non-GCA subjects from the same population were assembled and followed until December 31, 2013. Confirmed VTE and cerebrovascular events were identified through direct medical record review. Results The study population included 244 patients with GCA with a mean ± SD age at diagnosis of 76.2 ± 8.2 years (79% women) and an average length of follow-up of 10.2 ± 6.8 years. Compared to non-GCA subjects of similar age and sex, patients diagnosed with GCA had a higher incidence (%) of amaurosis fugax (cumulative incidence ± SE: 2.1 ± 0.9 versus 0, respectively; p = 0.014) but similar rates of stroke, transient ischemic attack (TIA), and VTE. Among patients with GCA, neither baseline characteristics nor laboratory parameters at diagnosis reliably predicted risk of VTE or cerebrovascular events. Conclusion In this population-based study, the incidence of VTE, stroke and TIA was similar in patients with GCA compared to non-GCA subjects. PMID:26901431

Renal disease disparities in Asian and Pacific-based populations in Hawai'i.

PubMed Central

Mau, Marjorie K.; West, Margaret; Sugihara, Jared; Kamaka, Martina; Mikami, Judy; Cheng, Shiuh-Feng

2003-01-01

The prevalence of end-stage renal disease (ESRD) in the United States is expected to double over the next 10 years. The identification of ethnic differences in the prevalence, treatment, morbidity, and mortality related to chronic kidney disease (CKD) is of great concern. Asian Americans comprise a rapidly expanding sector of the U.S. population and are reported to have ESRD growth rates that are approximately 50% higher than caucasians. Hawai'i has a large, well-established Asian and Pacific-based population that facilitates the examination of disparities in renal disease among the state's diverse ethnic groups. The prevalence of ESRD in Hawai'i has continued to rise due, in part, to high rates of diabetes, glomerulonephritis, and hypertension reported in Asian Americans and Pacific-based populations. ESRD patients in Hawai'i have a two-fold higher prevalence of glomerulonephritis, compared with the general ESRD population in the United States. Other potential sources of renal disparities-such as cultural factors, language barriers, and health access factors-among Hawaii's major ethnic groups are assessed. However, few studies have examined the relative contribution of these potential factors. Consequently, efforts to reduce and eventually eliminate renal disease disparities will require a better understanding of the major sources of health disparities, such as timely medical care, a diverse health workforce, and cultural/social barriers, that affect optimal health care practices in Asian and Pacific-based populations. PMID:14620708

Background and Data Configuration Process of a Nationwide Population-Based Study Using the Korean National Health Insurance System

PubMed Central

Song, Sun Ok; Jung, Chang Hee; Song, Young Duk; Park, Cheol-Young; Kwon, Hyuk-Sang; Cha, Bong Soo; Park, Joong-Yeol; Lee, Ki-Up

2014-01-01

Background The National Health Insurance Service (NHIS) recently signed an agreement to provide limited open access to the databases within the Korean Diabetes Association for the benefit of Korean subjects with diabetes. Here, we present the history, structure, contents, and way to use data procurement in the Korean National Health Insurance (NHI) system for the benefit of Korean researchers. Methods The NHIS in Korea is a single-payer program and is mandatory for all residents in Korea. The three main healthcare programs of the NHI, Medical Aid, and long-term care insurance (LTCI) provide 100% coverage for the Korean population. The NHIS in Korea has adopted a fee-for-service system to pay health providers. Researchers can obtain health information from the four databases of the insured that contain data on health insurance claims, health check-ups and LTCI. Results Metabolic disease as chronic disease is increasing with aging society. NHIS data is based on mandatory, serial population data, so, this might show the time course of disease and predict some disease progress, and also be used in primary and secondary prevention of disease after data mining. Conclusion The NHIS database represents the entire Korean population and can be used as a population-based database. The integrated information technology of the NHIS database makes it a world-leading population-based epidemiology and disease research platform. PMID:25349827

Background and data configuration process of a nationwide population-based study using the korean national health insurance system.

PubMed

Song, Sun Ok; Jung, Chang Hee; Song, Young Duk; Park, Cheol-Young; Kwon, Hyuk-Sang; Cha, Bong Soo; Park, Joong-Yeol; Lee, Ki-Up; Ko, Kyung Soo; Lee, Byung-Wan

2014-10-01

The National Health Insurance Service (NHIS) recently signed an agreement to provide limited open access to the databases within the Korean Diabetes Association for the benefit of Korean subjects with diabetes. Here, we present the history, structure, contents, and way to use data procurement in the Korean National Health Insurance (NHI) system for the benefit of Korean researchers. The NHIS in Korea is a single-payer program and is mandatory for all residents in Korea. The three main healthcare programs of the NHI, Medical Aid, and long-term care insurance (LTCI) provide 100% coverage for the Korean population. The NHIS in Korea has adopted a fee-for-service system to pay health providers. Researchers can obtain health information from the four databases of the insured that contain data on health insurance claims, health check-ups and LTCI. Metabolic disease as chronic disease is increasing with aging society. NHIS data is based on mandatory, serial population data, so, this might show the time course of disease and predict some disease progress, and also be used in primary and secondary prevention of disease after data mining. The NHIS database represents the entire Korean population and can be used as a population-based database. The integrated information technology of the NHIS database makes it a world-leading population-based epidemiology and disease research platform.

Probabilistic estimation of residential air exchange rates for population-based human exposure modeling

EPA Science Inventory

Residential air exchange rates (AERs) are a key determinant in the infiltration of ambient air pollution indoors. Population-based human exposure models using probabilistic approaches to estimate personal exposure to air pollutants have relied on input distributions from AER meas...

Adapting Technological Interventions to Meet the Needs of Priority Populations.

PubMed

Linke, Sarah E; Larsen, Britta A; Marquez, Becky; Mendoza-Vasconez, Andrea; Marcus, Bess H

2016-01-01

Cardiovascular diseases (CVD) comprise the leading cause of mortality worldwide, accounting for 3 in 10 deaths. Individuals with certain risk factors, including tobacco use, obesity, low levels of physical activity, type 2 diabetes mellitus, racial/ethnic minority status and low socioeconomic status, experience higher rates of CVD and are, therefore, considered priority populations. Technological devices such as computers and smartphones are now routinely utilized in research studies aiming to prevent CVD and its risk factors, and they are also rampant in the public and private health sectors. Traditional health behavior interventions targeting these risk factors have been adapted for technology-based approaches. This review provides an overview of technology-based interventions conducted in these priority populations as well as the challenges and gaps to be addressed in future research. Researchers currently possess tremendous opportunities to engage in technology-based implementation and dissemination science to help spread evidence-based programs focusing on CVD risk factors in these and other priority populations. Copyright © 2016 Elsevier Inc. All rights reserved.

Importance of population-based studies in clinical practice

PubMed Central

Ronnie, George; Ve, Ramesh Sathyamangalam; Velumuri, Lokapavani; Asokan, Rashima; Vijaya, Lingam

2011-01-01

In the last decade, there have been reports on the prevalence of glaucoma from the Vellore Eye Survey, Andhra Pradesh Eye Diseases Survey, Aravind Comprehensive Eye Survey, Chennai Glaucoma Study and West Bengal Glaucoma Study. Population-based studies provide important information regarding the prevalence and risk factors for glaucoma. They also highlight regional differences in the prevalence of various types of glaucoma. It is possible to gather important insights regarding the number of persons affected with glaucoma and the proportion with undiagnosed disease. We reviewed the different population-based studies from India and compare their findings. The lacunae in ophthalmic care that can be inferred from these studies are identified and possible reasons and solutions are discussed. We also discuss the clinical relevance of the various findings, and how it reflects on clinical practice in the country. Since India has a significantly high disease burden, we examine the possibility of population-based screening for disease in the Indian context. PMID:21150021

Trends and drivers of marine debris on the Atlantic coast of the United States 1997-2007

USGS Publications Warehouse

Ribic, C.A.; Sheavly, S.B.; Rugg, D.J.; Erdmann, Eric S.

2010-01-01

For the first time, we documented regional differences in amounts and long-term trends of marine debris along the US Atlantic coast. The Southeast Atlantic had low land-based and general-source debris loads as well as no increases despite a 19% increase in coastal population. The Northeast (8% population increase) also had low land-based and general-source debris loads and no increases. The Mid-Atlantic (10% population increase) fared the worst, with heavy land-based and general-source debris loads that increased over time. Ocean-based debris did not change in the Northeast where the fishery is relatively stable; it declined over the Mid-Atlantic and Southeast and was correlated with declining regional fisheries. Drivers, including human population, land use status, fishing activity, and oceanic current systems, had complex relationships with debris loads at local and regional scales. Management challenges remain undeniably large but solid information from long-term programs is one key to addressing this pressing pollution issue. ?? 2010.

Trends and drivers of marine debris on the Atlantic coast of the United States 1997-2007.

PubMed

Ribic, Christine A; Sheavly, Seba B; Rugg, David J; Erdmann, Eric S

2010-08-01

For the first time, we documented regional differences in amounts and long-term trends of marine debris along the US Atlantic coast. The Southeast Atlantic had low land-based and general-source debris loads as well as no increases despite a 19% increase in coastal population. The Northeast (8% population increase) also had low land-based and general-source debris loads and no increases. The Mid-Atlantic (10% population increase) fared the worst, with heavy land-based and general-source debris loads that increased over time. Ocean-based debris did not change in the Northeast where the fishery is relatively stable; it declined over the Mid-Atlantic and Southeast and was correlated with declining regional fisheries. Drivers, including human population, land use status, fishing activity, and oceanic current systems, had complex relationships with debris loads at local and regional scales. Management challenges remain undeniably large but solid information from long-term programs is one key to addressing this pressing pollution issue. Published by Elsevier Ltd.

Effects of climate change on plant population growth rate and community composition change.

PubMed

Chang, Xiao-Yu; Chen, Bao-Ming; Liu, Gang; Zhou, Ting; Jia, Xiao-Rong; Peng, Shao-Lin

2015-01-01

The impacts of climate change on forest community composition are still not well known. Although directional trends in climate change and community composition change were reported in recent years, further quantitative analyses are urgently needed. Previous studies focused on measuring population growth rates in a single time period, neglecting the development of the populations. Here we aimed to compose a method for calculating the community composition change, and to testify the impacts of climate change on community composition change within a relatively short period (several decades) based on long-term monitoring data from two plots-Dinghushan Biosphere Reserve, China (DBR) and Barro Colorado Island, Panama (BCI)-that are located in tropical and subtropical regions. We proposed a relatively more concise index, Slnλ, which refers to an overall population growth rate based on the dominant species in a community. The results indicated that the population growth rate of a majority of populations has decreased over the past few decades. This decrease was mainly caused by population development. The increasing temperature had a positive effect on population growth rates and community change rates. Our results promote understanding and explaining variations in population growth rates and community composition rates, and are helpful to predict population dynamics and population responses to climate change.

Forensic ancestry analysis in two Chinese minority populations using massively parallel sequencing of 165 ancestry-informative SNPs.

PubMed

He, Guanglin; Wang, Zheng; Wang, Mengge; Luo, Tao; Liu, Jing; Zhou, You; Gao, Bo; Hou, Yiping

2018-06-04

Ancestry inference based on single nucleotide polymorphism (SNP) with marked allele frequency differences in diverse populations (called ancestry-informative SNP, AISNP) is rapidly developed with the technology advancements of massively parallel sequencing (MPS). Despite the decade of exploration and broad public interest in the peopling of East-Asians, the genetic landscape of Chinese Silk Road populations based on the AISNPs is still little known. In this work, 206 unrelated individuals from Chinese Uyghur and Hui populations were firstly genotyped by 165 AISNPs (The Precision ID Ancestry Panel) using the Ion Torrent PGM system. The ethnic origin of two investigated populations and population structures and genetic relationships were subsequently investigated. The 165 AISNPs panel not only can differentiate Uyghur and Hui populations but also has potential applications in individual identification. Comprehensive population comparisons and admixture estimates demonstrated a predominantly higher European-related ancestry (36.30%) in Uyghurs than Huis (3.66%). Overall, the Precision ID Ancestry Panel can provide good resolution at the intercontinental level, but has limitations on the genetic homogeneous populations, such as the Hui and Han. Additional population-specific AISNPs remain necessary to get better-scale resolution within geographically proximate populations in East Asia. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Spatio-temporal population estimates for risk management

NASA Astrophysics Data System (ADS)

Cockings, Samantha; Martin, David; Smith, Alan; Martin, Rebecca

2013-04-01

Accurate estimation of population at risk from hazards and effective emergency management of events require not just appropriate spatio-temporal modelling of hazards but also of population. While much recent effort has been focused on improving the modelling and predictions of hazards (both natural and anthropogenic), there has been little parallel advance in the measurement or modelling of population statistics. Different hazard types occur over diverse temporal cycles, are of varying duration and differ significantly in their spatial extent. Even events of the same hazard type, such as flood events, vary markedly in their spatial and temporal characteristics. Conceptually and pragmatically then, population estimates should also be available for similarly varying spatio-temporal scales. Routine population statistics derived from traditional censuses or surveys are usually static representations in both space and time, recording people at their place of usual residence on census/survey night and presenting data for administratively defined areas. Such representations effectively fix the scale of population estimates in both space and time, which is unhelpful for meaningful risk management. Over recent years, the Pop24/7 programme of research, based at the University of Southampton (UK), has developed a framework for spatio-temporal modelling of population, based on gridded population surfaces. Based on a data model which is fully flexible in terms of space and time, the framework allows population estimates to be produced for any time slice relevant to the data contained in the model. It is based around a set of origin and destination centroids, which have capacities, spatial extents and catchment areas, all of which can vary temporally, such as by time of day, day of week, season. A background layer, containing information on features such as transport networks and landuse, provides information on the likelihood of people being in certain places at specific times. Unusual patterns associated with special events can also be modelled and the framework is fully volume preserving. Outputs from the model are gridded population surfaces for the specified time slice, either for total population or by sub-groups (e.g. age). Software to implement the models (SurfaceBuilder247) has been developed and pre-processed layers for typical time slices for England and Wales in 2001 and 2006 are available for UK academic purposes. The outputs and modelling framework from the Pop24/7 programme provide significant opportunities for risk management applications. For estimates of mid- to long-term cumulative population exposure to hazards, such as in flood risk mapping, populations can be produced for numerous time slices and integrated with flood models. For applications in emergency response/ management, time-specific population models can be used as seeds for agent-based models or other response/behaviour models. Estimates for sub-groups of the population also permit exploration of vulnerability through space and time. This paper outlines the requirements for effective spatio-temporal population models for risk management. It then describes the Pop24/7 framework and illustrates its potential for risk management through presentation of examples from natural and anthropogenic hazard applications. The paper concludes by highlighting key challenges for future research in this area.

Development of Seven Microsatellite Markers Using Next Generation Sequencing for the Conservation on the Korean Population of Dorcus hopei (E. Saunders, 1854) (Coleoptera, Lucanidae)

PubMed Central

Kang, Tae Hwa; Han, Sang Hoon; Park, Sun Jae

2015-01-01

We developed microsatellite markers for genetic structural analyses of Dorcus hopei, a stag beetle species, using next generation sequencing and polymerase chain reaction (PCR)-based genotyping for regional populations. A total of 407,070,351 base pairs of genomic DNA containing >4000 microsatellite loci except AT repeats were sequenced. From 76 loci selected for primer design, 27 were polymorphic. Of these 27 markers, 10 were tested on three regional populations: two Chinese (Shichuan and Guangxi) and one Korean (Wanju). Three markers were excluded due to inconsistent amplification, genotyping errors, and Hardy-Weinberg equilibrium (HWE). By multi-locus genotyping, the allele number, observed heterozygosity and polymorphism information content of seven microsatellite loci were ranged 2‒10, 0.1333‒1.0000, and 0.1228‒0.8509, respectively. In an analysis on the genetic differentiation among regional populations including one Japanese population and one cross-breeding population, the individual colored bar-plots showed that both Chinese populations were closer to each other than to the Far East Asian populations. In Far East Asian populations, Wanju and Nirasaki populations could not be distinguished from each other because the frequency of genetic contents was very similar in some individuals of two populations. Moreover, the cross-breeding population contained all patterns of genetic contents shown in Chinese, Korean, and Japanese populations, compared with the genetic content frequency of each regional population. As a result, we examined whether the cross-breeding population might be a hybrid population, and might contain a possibility of interbreeding with Chinese populations in parental generations. Therefore, these markers will be useful for analyses of genetic diversity in populations, genetic relationships between regional populations, genetic structure analyses, and origin tests. PMID:26370965

Prognostic scoring systems for myelodysplastic syndromes (MDS) in a population-based setting: a report from the Swedish MDS register.

PubMed

Moreno Berggren, Daniel; Folkvaljon, Yasin; Engvall, Marie; Sundberg, Johan; Lambe, Mats; Antunovic, Petar; Garelius, Hege; Lorenz, Fryderyk; Nilsson, Lars; Rasmussen, Bengt; Lehmann, Sören; Hellström-Lindberg, Eva; Jädersten, Martin; Ejerblad, Elisabeth

2018-06-01

The myelodysplastic syndromes (MDS) have highly variable outcomes and prognostic scoring systems are important tools for risk assessment and to guide therapeutic decisions. However, few population-based studies have compared the value of the different scoring systems. With data from the nationwide Swedish population-based MDS register we validated the International Prognostic Scoring System (IPSS), revised IPSS (IPSS-R) and the World Health Organization (WHO) Classification-based Prognostic Scoring System (WPSS). We also present population-based data on incidence, clinical characteristics including detailed cytogenetics and outcome from the register. The study encompassed 1329 patients reported to the register between 2009 and 2013, 14% of these had therapy-related MDS (t-MDS). Based on the MDS register, the yearly crude incidence of MDS in Sweden was 2·9 per 100 000 inhabitants. IPSS-R had a significantly better prognostic power than IPSS (P < 0·001). There was a trend for better prognostic power of IPSS-R compared to WPSS (P = 0·05) and for WPSS compared to IPSS (P = 0·07). IPSS-R was superior to both IPSS and WPSS for patients aged ≤70 years. Patients with t-MDS had a worse outcome compared to de novo MDS (d-MDS), however, the validity of the prognostic scoring systems was comparable for d-MDS and t-MDS. In conclusion, population-based studies are important to validate prognostic scores in a 'real-world' setting. In our nationwide cohort, the IPSS-R showed the best predictive power. © 2018 John Wiley & Sons Ltd.

Land Use as a Driver of Patterns of Rodenticide Exposure in Modeled Kit Fox Populations

PubMed Central

Nogeire, Theresa M.; Lawler, Joshua J.; Schumaker, Nathan H.; Cypher, Brian L.; Phillips, Scott E.

2015-01-01

Although rodenticides are increasingly regulated, they nonetheless cause poisonings in many non-target wildlife species. Second-generation anticoagulant rodenticide use is common in agricultural and residential landscapes. Here, we use an individual-based population model to assess potential population-wide effects of rodenticide exposures on the endangered San Joaquin kit fox (Vulpes macrotis mutica). We estimate likelihood of rodenticide exposure across the species range for each land cover type based on a database of reported pesticide use and literature. Using a spatially-explicit population model, we find that 36% of modeled kit foxes are likely exposed, resulting in a 7-18% decline in the range-wide modeled kit fox population that can be linked to rodenticide use. Exposures of kit foxes in low-density developed areas accounted for 70% of the population-wide exposures to rodenticides. We conclude that exposures of non-target kit foxes could be greatly mitigated by reducing the use of second-generation anticoagulant rodenticides in low-density developed areas near vulnerable populations. PMID:26244655

STR data for the AmpFlSTR Identifiler loci from Swedish population in comparison to European, as well as with non-European population.

PubMed

Montelius, Kerstin; Karlsson, Andreas O; Holmlund, Gunilla

2008-06-01

The modern Swedish population is a mixture of people that originate from different parts of the world. This is also the truth for the clients participating in the paternity cases investigated at the department. Calculations based on a Swedish frequency database only, could give us overestimated figures of probability and power of exclusion in cases including clients with a genetic background other than Swedish. Here, we describe allele frequencies regarding the markers in the Identifiler-kit. We have compared three sets of population samples; Swedish, European and non-European to investigate how these three groups of population samples differ. Also, all three population sets were compared to data reported from other European and non-European populations. Swedish allele frequencies for the 15 autosomal STRs included in the Identifiler kit were obtained from unrelated blood donors with Swedish names. The European and non-European frequencies were based on DNA-profiles of alleged fathers from our paternity cases in 2005 and 2006.

Modeling wildlife populations with HexSim

EPA Science Inventory

HexSim is a framework for constructing spatially-explicit, individual-based computer models designed for simulating terrestrial wildlife population dynamics and interactions. HexSim is useful for a broad set of modeling applications including population viability analysis for on...

An individual-based model of zebrafish population dynamics accounting for energy dynamics.

PubMed

Beaudouin, Rémy; Goussen, Benoit; Piccini, Benjamin; Augustine, Starrlight; Devillers, James; Brion, François; Péry, Alexandre R R

2015-01-01

Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model) was coupled to an individual based model of zebrafish population dynamics (IBM model). Next, we fitted the DEB model to new experimental data on zebrafish growth and reproduction thus improving existing models. We further analysed the DEB-model and DEB-IBM using a sensitivity analysis. Finally, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding), it can already serve to predict the impact of compounds at the population level.

An Individual-Based Model of Zebrafish Population Dynamics Accounting for Energy Dynamics

PubMed Central

Beaudouin, Rémy; Goussen, Benoit; Piccini, Benjamin; Augustine, Starrlight; Devillers, James; Brion, François; Péry, Alexandre R. R.

2015-01-01

Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model) was coupled to an individual based model of zebrafish population dynamics (IBM model). Next, we fitted the DEB model to new experimental data on zebrafish growth and reproduction thus improving existing models. We further analysed the DEB-model and DEB-IBM using a sensitivity analysis. Finally, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding), it can already serve to predict the impact of compounds at the population level. PMID:25938409

Mapping the Risk of Snakebite in Sri Lanka - A National Survey with Geospatial Analysis.

PubMed

Ediriweera, Dileepa Senajith; Kasturiratne, Anuradhani; Pathmeswaran, Arunasalam; Gunawardena, Nipul Kithsiri; Wijayawickrama, Buddhika Asiri; Jayamanne, Shaluka Francis; Isbister, Geoffrey Kennedy; Dawson, Andrew; Giorgi, Emanuele; Diggle, Peter John; Lalloo, David Griffith; de Silva, Hithanadura Janaka

2016-07-01

There is a paucity of robust epidemiological data on snakebite, and data available from hospitals and localized or time-limited surveys have major limitations. No study has investigated the incidence of snakebite across a whole country. We undertook a community-based national survey and model based geostatistics to determine incidence, envenoming, mortality and geographical pattern of snakebite in Sri Lanka. The survey was designed to sample a population distributed equally among the nine provinces of the country. The number of data collection clusters was divided among districts in proportion to their population. Within districts clusters were randomly selected. Population based incidence of snakebite and significant envenoming were estimated. Model-based geostatistics was used to develop snakebite risk maps for Sri Lanka. 1118 of the total of 14022 GN divisions with a population of 165665 (0.8%of the country's population) were surveyed. The crude overall community incidence of snakebite, envenoming and mortality were 398 (95% CI: 356-441), 151 (130-173) and 2.3 (0.2-4.4) per 100000 population, respectively. Risk maps showed wide variation in incidence within the country, and snakebite hotspots and cold spots were determined by considering the probability of exceeding the national incidence. This study provides community based incidence rates of snakebite and envenoming for Sri Lanka. The within-country spatial variation of bites can inform healthcare decision making and highlights the limitations associated with estimates of incidence from hospital data or localized surveys. Our methods are replicable, and these models can be adapted to other geographic regions after re-estimating spatial covariance parameters for the particular region.

Sequencing-Based Analysis of the Bacterial and Fungal Composition of Kefir Grains and Milks from Multiple Sources

PubMed Central

Marsh, Alan J.; O’Sullivan, Orla; Hill, Colin; Ross, R. Paul; Cotter, Paul D.

2013-01-01

Kefir is a fermented milk-based beverage to which a number of health-promoting properties have been attributed. The microbes responsible for the fermentation of milk to produce kefir consist of a complex association of bacteria and yeasts, bound within a polysaccharide matrix, known as the kefir grain. The consistency of this microbial population, and that present in the resultant beverage, has been the subject of a number of previous, almost exclusively culture-based, studies which have indicated differences depending on geographical location and culture conditions. However, culture-based identification studies are limited by virtue of only detecting species with the ability to grow on the specific medium used and thus culture-independent, molecular-based techniques offer the potential for a more comprehensive analysis of such communities. Here we describe a detailed investigation of the microbial population, both bacterial and fungal, of kefir, using high-throughput sequencing to analyse 25 kefir milks and associated grains sourced from 8 geographically distinct regions. This is the first occasion that this technology has been employed to investigate the fungal component of these populations or to reveal the microbial composition of such an extensive number of kefir grains or milks. As a result several genera and species not previously identified in kefir were revealed. Our analysis shows that the bacterial populations in kefir are dominated by 2 phyla, the Firmicutes and the Proteobacteria. It was also established that the fungal populations of kefir were dominated by the genera Kazachstania, Kluyveromyces and Naumovozyma, but that a variable sub-dominant population also exists. PMID:23894461

Sequencing-based analysis of the bacterial and fungal composition of kefir grains and milks from multiple sources.

PubMed

Marsh, Alan J; O'Sullivan, Orla; Hill, Colin; Ross, R Paul; Cotter, Paul D

2013-01-01

Kefir is a fermented milk-based beverage to which a number of health-promoting properties have been attributed. The microbes responsible for the fermentation of milk to produce kefir consist of a complex association of bacteria and yeasts, bound within a polysaccharide matrix, known as the kefir grain. The consistency of this microbial population, and that present in the resultant beverage, has been the subject of a number of previous, almost exclusively culture-based, studies which have indicated differences depending on geographical location and culture conditions. However, culture-based identification studies are limited by virtue of only detecting species with the ability to grow on the specific medium used and thus culture-independent, molecular-based techniques offer the potential for a more comprehensive analysis of such communities. Here we describe a detailed investigation of the microbial population, both bacterial and fungal, of kefir, using high-throughput sequencing to analyse 25 kefir milks and associated grains sourced from 8 geographically distinct regions. This is the first occasion that this technology has been employed to investigate the fungal component of these populations or to reveal the microbial composition of such an extensive number of kefir grains or milks. As a result several genera and species not previously identified in kefir were revealed. Our analysis shows that the bacterial populations in kefir are dominated by 2 phyla, the Firmicutes and the Proteobacteria. It was also established that the fungal populations of kefir were dominated by the genera Kazachstania, Kluyveromyces and Naumovozyma, but that a variable sub-dominant population also exists.

[Are Interventions Promoting Physical Activity Cost-Effective? A Systematic Review of Reviews].

PubMed

Rütten, Alfred; Abu-Omar, Karim; Burlacu, Ionut; Schätzlein, Valentin; Suhrcke, Marc

2017-03-01

On the basis of international published reviews, this systematic review aims to determine the health economic benefits of interventions promoting physical activity.This review of reviews is based on a systematic literature research in 10 databases (e. g. PubMed, Scopus, SPORTDiscus) supplemented by hand searches from January 2000 to October 2015. Publications were considered in the English or German language only. Results of identified reviews were derived.In total, 18 reviews were identified that could be attributed to interventions promoting physical activity (2 reviews focusing on population-based physical activity interventions, 10 reviews on individual-based and 6 reviews on both population-based and individual-based physical activity interventions). Results showed that population-based physical activity interventions are of great health economic potential if reaching a wider population at comparably low costs. Outstanding are political and environmental strategies, as well as interventions supporting behavioural change through information. The most comprehensive documentation for interventions promoting physical activity could be found for individual-based strategies (i. e. exercise advice or exercise programs). However, such programs are comparatively less cost-effective due to limited reach and higher utilization of resources.The present study provides an extensive review and analysis of the current international state of research regarding the health economic evaluation of interventions promoting physical activity. Results show favourable cost-effectiveness for interventions promoting physical activity, though significant differences in the effectiveness between various interventions were noticed. The greatest potential for cost-effectiveness can be seen in population-based interventions. At the same time, there is a need to acknowledge the limitations of the economic evidence in this field which are attributable to methodological challenges and research deficits. © Georg Thieme Verlag KG Stuttgart · New York.

Count data, detection probabilities, and the demography, dynamics, distribution, and decline of amphibians.

PubMed

Schmidt, Benedikt R

2003-08-01

The evidence for amphibian population declines is based on count data that were not adjusted for detection probabilities. Such data are not reliable even when collected using standard methods. The formula C = Np (where C is a count, N the true parameter value, and p is a detection probability) relates count data to demography, population size, or distributions. With unadjusted count data, one assumes a linear relationship between C and N and that p is constant. These assumptions are unlikely to be met in studies of amphibian populations. Amphibian population data should be based on methods that account for detection probabilities.

Effective number of breeding adults in Bufo bufo estimated from age-specific variation at minisatellite loci

USGS Publications Warehouse

Scribner, K.T.; Arntzen, J.W.; Burke, T.

1997-01-01

Estimates of the effective number of breeding adults were derived for three semi-isolated populations of the common toad Bufo bufo based on temporal (i.e. adult-progeny) variance in allele frequency for three highly polymorphic minisatellite loci. Estimates of spatial variance in allele frequency among populations and of age-specific measures of genetic variability are also described. Each population was characterized by a low effective adult breeding number (N(b)) based on a large age-specific variance in minisatellite allele frequency. Estimates of N(b) (range 21-46 for population means across three loci) were ??? 55-230-fold lower than estimates of total adult census size. The implications of low effective breeding numbers for long-term maintenance of genetic variability and population viability are discussed relative to the species' reproductive ecology, current land-use practices, and present and historical habitat modification and loss. The utility of indirect measures of population parameters such as N(b) and N(e) based on time-series data of minisatellite allele frequencies is discussed relative to similar measures estimated from commonly used genetic markers such as protein allozymes.

An Analysis of Communication as a Key Component in Leadership with Diverse School Populations

ERIC Educational Resources Information Center

Cagle, Jo E.; Wiley, Sandy T.

2012-01-01

"Effective Communication as an Essential Element of Leaders with Diverse School Populations" describes a problem based learning project focused on issues related to practices used by principals to address diverse school populations. The team found that communication between principals and diverse populations in schools was a challenge.…

Mitigation of atrazine, S-metolachlor, and diazinon using common aquatic emergent vegetation

USDA-ARS?s Scientific Manuscript database

Based on current population rates, by the year 2050, the population of the United States will reach over 418 million, while the global population will reach 9.6 billion. To continue providing safe food and fiber for this population increase, agriculture must balance the mixture of natural resources...

A random spatial sampling method in a rural developing nation

Treesearch

Michelle C. Kondo; Kent D.W. Bream; Frances K. Barg; Charles C. Branas

2014-01-01

Nonrandom sampling of populations in developing nations has limitations and can inaccurately estimate health phenomena, especially among hard-to-reach populations such as rural residents. However, random sampling of rural populations in developing nations can be challenged by incomplete enumeration of the base population. We describe a stratified random sampling method...

11 CFR 110.18 - Voting age population.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 11 Federal Elections 1 2011-01-01 2011-01-01 false Voting age population. 110.18 Section 110.18... PROHIBITIONS § 110.18 Voting age population. There is annually published by the Department of Commerce in the Federal Register an estimate of the voting age population based on an estimate of the voting age...

11 CFR 110.18 - Voting age population.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 11 Federal Elections 1 2013-01-01 2012-01-01 true Voting age population. 110.18 Section 110.18... PROHIBITIONS § 110.18 Voting age population. There is annually published by the Department of Commerce in the Federal Register an estimate of the voting age population based on an estimate of the voting age...

11 CFR 110.18 - Voting age population.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 11 Federal Elections 1 2014-01-01 2014-01-01 false Voting age population. 110.18 Section 110.18... PROHIBITIONS § 110.18 Voting age population. There is annually published by the Department of Commerce in the Federal Register an estimate of the voting age population based on an estimate of the voting age...

11 CFR 110.18 - Voting age population.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 11 Federal Elections 1 2012-01-01 2012-01-01 false Voting age population. 110.18 Section 110.18... PROHIBITIONS § 110.18 Voting age population. There is annually published by the Department of Commerce in the Federal Register an estimate of the voting age population based on an estimate of the voting age...

Estimation of census and effective population sizes: the increasing usefulness of DNA-based approaches

Treesearch

Gordon Luikart; Nils Ryman; David A. Tallmon; Michael K. Schwartz; Fred W. Allendorf

2010-01-01

Population census size (NC) and effective population sizes (Ne) are two crucial parameters that influence population viability, wildlife management decisions, and conservation planning. Genetic estimators of both NC and Ne are increasingly widely used because molecular markers are increasingly available, statistical methods are improving rapidly, and genetic estimators...

Genetic structure of American chestnut populations based on neutral DNA markers

Treesearch

Thomas L. Kubisiak; James H. Roberds

2006-01-01

Microsatellite and RAPD markers suggest that American chestnut exists as a highly variable species. Even at the margins of its natural range, with a large proportion of its genetic variability occurring within populations (~95%). A statistically significant proportion also exists among population. Although genetic differentiation among populations has taken place, no...

Phylogeography, intraspecific structure and sex-biased dispersal of Dall's porpoise, Phocoenoides dalli, revealed by mitochondrial and microsatellite DNA analyses.

PubMed

Escorza-Treviño, S; Dizon, A E

2000-08-01

Mitochondrial DNA (mtDNA) control-region sequences and microsatellite loci length polymorphisms were used to estimate phylogeographical patterns (historical patterns underlying contemporary distribution), intraspecific population structure and gender-biased dispersal of Phocoenoides dalli dalli across its entire range. One-hundred and thirteen animals from several geographical strata were sequenced over 379 bp of mtDNA, resulting in 58 mtDNA haplotypes. Analysis using F(ST) values (based on haplotype frequencies) and phi(ST) values (based on frequencies and genetic distances between haplotypes) yielded statistically significant separation (bootstrap values P < 0.05) among most of the stocks currently used for management purposes. A minimum spanning network of haplotypes showed two very distinctive clusters, differentially occupied by western and eastern populations, with some common widespread haplotypes. This suggests some degree of phyletic radiation from west to east, superimposed on gene flow. Highly male-biased migration was detected for several population comparisons. Nuclear microsatellite DNA markers (119 individuals and six loci) provided additional support for population subdivision and gender-biased dispersal detected in the mtDNA sequences. Analysis using F(ST) values (based on allelic frequencies) yielded statistically significant separation between some, but not all, populations distinguished by mtDNA analysis. R(ST) values (based on frequencies of and genetic distance between alleles) showed no statistically significant subdivision. Again, highly male-biased dispersal was detected for all population comparisons, suggesting, together with morphological and reproductive data, the existence of sexual selection. Our molecular results argue for nine distinct dalli-type populations that should be treated as separate units for management purposes.

Social-ecological interactions, management panaceas, and the future of wild fish populations

PubMed Central

van Poorten, Brett T.; Arlinghaus, Robert; Daedlow, Katrin; Haertel-Borer, Susanne S.

2011-01-01

We explored the social and ecological outcomes associated with emergence of a management panacea designed to govern a stochastic renewable natural resource. To that end, we constructed a model of a coupled social-ecological system of recreational fisheries in which a manager supports naturally fluctuating stocks by stocking fish in response to harvest-driven satisfaction of resource users. The realistic assumption of users remembering past harvest experiences when exploiting a stochastically fluctuating fish population facilitates the emergence of a stocking-based management panacea over time. The social benefits of panacea formation involve dampening natural population fluctuations and generating stability of user satisfaction. It also maintains the resource but promotes the eventual replacement of wild fish by hatchery-descended fish. Our analyses show this outcome is particularly likely when hatchery-descended fish are reasonably fit (e.g., characterized by similar survival relative to wild fish) and/or when natural recruitment of the wild population is low (e.g., attributable to habitat deterioration), which leaves the wild population with little buffer against competition by stocked fish. The potential for release-based panacea formation is particularly likely under user-based management regimes and should be common in a range of social-ecological systems (e.g., fisheries, forestry), whenever user groups are entitled to engage in release or replanting strategies. The net result will be the preservation of a renewable resource through user-based incentives, but the once natural populations are likely to be altered and to host nonnative genotypes. This risks other ecosystem services and the future of wild populations. PMID:21742983

Do we need demographic data to forecast plant population dynamics?

USGS Publications Warehouse

Tredennick, Andrew T.; Hooten, Mevin B.; Adler, Peter B.

2017-01-01

Rapid environmental change has generated growing interest in forecasts of future population trajectories. Traditional population models built with detailed demographic observations from one study site can address the impacts of environmental change at particular locations, but are difficult to scale up to the landscape and regional scales relevant to management decisions. An alternative is to build models using population-level data that are much easier to collect over broad spatial scales than individual-level data. However, it is unknown whether models built using population-level data adequately capture the effects of density-dependence and environmental forcing that are necessary to generate skillful forecasts.Here, we test the consequences of aggregating individual responses when forecasting the population states (percent cover) and trajectories of four perennial grass species in a semi-arid grassland in Montana, USA. We parameterized two population models for each species, one based on individual-level data (survival, growth and recruitment) and one on population-level data (percent cover), and compared their forecasting accuracy and forecast horizons with and without the inclusion of climate covariates. For both models, we used Bayesian ridge regression to weight the influence of climate covariates for optimal prediction.In the absence of climate effects, we found no significant difference between the forecast accuracy of models based on individual-level data and models based on population-level data. Climate effects were weak, but increased forecast accuracy for two species. Increases in accuracy with climate covariates were similar between model types.In our case study, percent cover models generated forecasts as accurate as those from a demographic model. For the goal of forecasting, models based on aggregated individual-level data may offer a practical alternative to data-intensive demographic models. Long time series of percent cover data already exist for many plant species. Modelers should exploit these data to predict the impacts of environmental change.

Double Trouble at High Density: Cross-Level Test of Resource-Related Adaptive Plasticity and Crowding-Related Fitness

PubMed Central

Gergs, André; Preuss, Thomas G.; Palmqvist, Annemette

2014-01-01

Population size is often regulated by negative feedback between population density and individual fitness. At high population densities, animals run into double trouble: they might concurrently suffer from overexploitation of resources and also from negative interference among individuals regardless of resource availability, referred to as crowding. Animals are able to adapt to resource shortages by exhibiting a repertoire of life history and physiological plasticities. In addition to resource-related plasticity, crowding might lead to reduced fitness, with consequences for individual life history. We explored how different mechanisms behind resource-related plasticity and crowding-related fitness act independently or together, using the water flea Daphnia magna as a case study. For testing hypotheses related to mechanisms of plasticity and crowding stress across different biological levels, we used an individual-based population model that is based on dynamic energy budget theory. Each of the hypotheses, represented by a sub-model, is based on specific assumptions on how the uptake and allocation of energy are altered under conditions of resource shortage or crowding. For cross-level testing of different hypotheses, we explored how well the sub-models fit individual level data and also how well they predict population dynamics under different conditions of resource availability. Only operating resource-related and crowding-related hypotheses together enabled accurate model predictions of D. magna population dynamics and size structure. Whereas this study showed that various mechanisms might play a role in the negative feedback between population density and individual life history, it also indicated that different density levels might instigate the onset of the different mechanisms. This study provides an example of how the integration of dynamic energy budget theory and individual-based modelling can facilitate the exploration of mechanisms behind the regulation of population size. Such understanding is important for assessment, management and the conservation of populations and thereby biodiversity in ecosystems. PMID:24626228

Evidenced-Based Treatment of Depression in the College Population

ERIC Educational Resources Information Center

Lee, Carolyn L.

2005-01-01

This review explores evidence-based treatment for depression within the college and university population. Treatments for depression in adults are among the most rigorous studied treatment modalities in the psychotherapy literature, providing consistent evidence for the efficacy of at least two treatments, cognitive behavioral therapy and…

Human Prostate Side Population Cells Demonstrate Stem Cell Properties in Recombination with Urogenital Sinus Mesenchyme

PubMed Central

Foster, Barbara A.; Gangavarapu, Kalyan J.; Mathew, Grinu; Azabdaftari, Gissou; Morrison, Carl D.; Miller, Austin; Huss, Wendy J.

2013-01-01

Stem cell enrichment provides a tool to examine prostate stem cells obtained from benign and malignant tissue. Functional assays can enrich stem cells based on common stem cell phenotypes, such as high ATP binding cassette (ABC) transporter mediated efflux of Hoechst substrates (side population assay). This functional assay is based upon mechanisms that protect cells from environmental insult thus contributing to the survival and protection of the stem cell population. We have isolated and analyzed cells digested from twelve clinical prostate specimens based on the side population assay. Prostate stem cell properties of the isolated cells were tested by serial recombination with rat urogenital mesenchyme. Recombinants with side population cells demonstrate an increase in the frequency of human ductal growth and the number of glands per recombinant when compared to recombinants with non-side population cells. Isolated cells were capable of prostatic growth for up to three generations in the recombination assay with as little as 125 sorted prostate cells. The ability to reproducibly use cells isolated by fluorescence activated cell sorting from human prostate tissue is an essential step to a better understanding of human prostate stem cell biology. ABC transporter G2 (ABCG2) was expressed in recombinants from side population cells indicating the side population cells have self-renewal properties. Epithelial cell differentiation of recombinants was determined by immunohistochemical analysis for expression of the basal, luminal, and neuroendocrine markers, p63, androgen receptor, prostate specific antigen, and chromogranin A, respectively. Thus, the ABCG2 expressing side population demonstrates multipotency and self-renewal properties indicating stem cells are within this population. PMID:23383057

Intraspecific evolutionary relationships among peregrine falcons in western North American high latitudes

PubMed Central

Sage, George K.; Sonsthagen, Sarah A.; Gravley, Meg C.; Swem, Ted; Williams, Jeffrey C.; Longmire, Jonathan L.; Ambrose, Skip; Flamme, Melanie J.; Lewis, Stephen B.; Phillips, Laura; Anderson, Clifford; White, Clayton M.

2017-01-01

Subspecies relationships within the peregrine falcon (Falco peregrinus) have been long debated because of the polytypic nature of melanin-based plumage characteristics used in subspecies designations and potential differentiation of local subpopulations due to philopatry. In North America, understanding the evolutionary relationships among subspecies may have been further complicated by the introduction of captive bred peregrines originating from non-native stock, as part of recovery efforts associated with mid 20th century population declines resulting from organochloride pollution. Alaska hosts all three nominal subspecies of North American peregrine falcons–F. p. tundrius, anatum, and pealei–for which distributions in Alaska are broadly associated with nesting locales within Arctic, boreal, and south coastal maritime habitats, respectively. Unlike elsewhere, populations of peregrine falcon in Alaska were not augmented by captive-bred birds during the late 20th century recovery efforts. Population genetic differentiation analyses of peregrine populations in Alaska, based on sequence data from the mitochondrial DNA control region and fragment data from microsatellite loci, failed to uncover genetic distinction between populations of peregrines occupying Arctic and boreal Alaskan locales. However, the maritime subspecies, pealei, was genetically differentiated from Arctic and boreal populations, and substructured into eastern and western populations. Levels of interpopulational gene flow between anatum and tundrius were generally higher than between pealei and either anatum or tundrius. Estimates based on both marker types revealed gene flow between augmented Canadian populations and unaugmented Alaskan populations. While we make no attempt at formal taxonomic revision, our data suggest that peregrine falcons occupying habitats in Alaska and the North Pacific coast of North America belong to two distinct regional groupings–a coastal grouping (pealei) and a boreal/Arctic grouping (currently anatum and tundrius)–each comprised of discrete populations that are variously intra-regionally connected. PMID:29149202

Assessing three fish species ecological status in Colorado River, Grand Canyon based on physical habitat and population models.

PubMed

Yao, Weiwei; Chen, Yuansheng

2018-04-01

Colorado River is a unique ecosystem and provides important ecological services such as habitat for fish species as well as water power energy supplies. River management for this ecosystem requires assessment and decision support tools for fish which involves protecting, restoring as well as forecasting of future conditions. In this paper, a habitat and population model was developed and used to determine the levels of fish habitat suitability and population density in Colorado River between Lees Ferry and Lake Mead. The short term target fish populations are also predicted based on native fish recovery strategy. This model has been developed by combining hydrodynamics, heat transfer and sediment transport models with a habitat suitability index model and then coupling with habitat model into life stage population model. The fish were divided into four life stages according to the fish length. Three most abundant and typical native and non-native fish were selected as target species, which are rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta) and flannelmouth sucker (Catostomus latipinnis). Flow velocity, water depth, water temperature and substrates were used as the suitability indicators in habitat model and overall suitability index (OSI) as well as weight usable area (WUA) was used as an indicator in population model. A comparison was made between simulated fish population alteration and surveyed fish number fluctuation during 2000 to 2009. The application of this habitat and population model indicates that this model can be accurate present habitat situation and targets fish population dynamics of in the study areas. The analysis also indicates the flannelmouth sucker population will steadily increase while the rainbow trout will decrease based on the native fish recovery scheme. Copyright © 2018. Published by Elsevier Inc.

Contrasting results from molecular and pedigree-based population diversity measures in captive zebra highlight challenges facing genetic management of zoo populations.

PubMed

Ito, Hideyuki; Ogden, Rob; Langenhorst, Tanya; Inoue-Murayama, Miho

2017-01-01

Zoo conservation breeding programs manage the retention of population genetic diversity through analysis of pedigree records. The range of demographic and genetic indices determined through pedigree analysis programs allows the conservation of diversity to be monitored relative to the particular founder population for a species. Such approaches are based on a number of well-documented founder assumptions, however without knowledge of actual molecular genetic diversity there is a risk that pedigree-based measures will be misinterpreted and population genetic diversity misunderstood. We examined the genetic diversity of the captive populations of Grevy's zebra, Hartmann's mountain zebra and plains zebra in Japan and the United Kingdom through analysis of mitochondrial DNA sequences. Very low nucleotide variability was observed in Grevy's zebra. The results were evaluated with respect to current and historic diversity in the wild, and indicate that low genetic diversity in the captive population is likely a result of low founder diversity, which in turn suggests relatively low wild genetic diversity prior to recent population declines. Comparison of molecular genetic diversity measures with analogous diversity indices generated from the studbook data for Grevy's zebra and Hartmann's mountain zebra show contrasting patterns, with Grevy's zebra displaying markedly less molecular diversity than mountain zebra, despite studbook analysis indicating that the Grevy's zebra population has substantially more founders, greater effective population size, lower mean kinship, and has suffered less loss of gene diversity. These findings emphasize the need to validate theoretical estimates of genetic diversity in captive breeding programs with empirical molecular genetic data. Zoo Biol. 36:87-94, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The Impact of Selection, Gene Conversion, and Biased Sampling on the Assessment of Microbial Demography.

PubMed

Lapierre, Marguerite; Blin, Camille; Lambert, Amaury; Achaz, Guillaume; Rocha, Eduardo P C

2016-07-01

Recent studies have linked demographic changes and epidemiological patterns in bacterial populations using coalescent-based approaches. We identified 26 studies using skyline plots and found that 21 inferred overall population expansion. This surprising result led us to analyze the impact of natural selection, recombination (gene conversion), and sampling biases on demographic inference using skyline plots and site frequency spectra (SFS). Forward simulations based on biologically relevant parameters from Escherichia coli populations showed that theoretical arguments on the detrimental impact of recombination and especially natural selection on the reconstructed genealogies cannot be ignored in practice. In fact, both processes systematically lead to spurious interpretations of population expansion in skyline plots (and in SFS for selection). Weak purifying selection, and especially positive selection, had important effects on skyline plots, showing patterns akin to those of population expansions. State-of-the-art techniques to remove recombination further amplified these biases. We simulated three common sampling biases in microbiological research: uniform, clustered, and mixed sampling. Alone, or together with recombination and selection, they further mislead demographic inferences producing almost any possible skyline shape or SFS. Interestingly, sampling sub-populations also affected skyline plots and SFS, because the coalescent rates of populations and their sub-populations had different distributions. This study suggests that extreme caution is needed to infer demographic changes solely based on reconstructed genealogies. We suggest that the development of novel sampling strategies and the joint analyzes of diverse population genetic methods are strictly necessary to estimate demographic changes in populations where selection, recombination, and biased sampling are present. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

A SNP genetic linkage map based on the ‘Hamilton’ by ‘Spencer’ recombinant inbred line (RIL) population identified QTL for seed Isoflavone contents in soybean

USDA-ARS?s Scientific Manuscript database

Soybean is one of the most important crops worldwide for its protein, oil as well as the health beneficial phytoestrogens or isoflavone. This study reports a relatively dense SNP-Based genetic map based on ‘Hamilton’ by ‘Spencer’ recombinant inbred line (RIL) population and quantitative t...

Differences in Mental Health for Sexual Minority Students at Faith-Based Colleges/Universities and in the General College/University Population

ERIC Educational Resources Information Center

Cunningham, Jamal R.

2017-01-01

The present study is an examination of mental health between lesbian, gay, bisexual, queer, and questioning students at faith based colleges/universities (FBCU) and the general college/university population (GCUP), which includes mostly non-faith based colleges/universities (NFBCU) as well as some FBCU. Current literature on this topic is sparse.…

Acute myeloid leukemia in the real world: why population-based registries are needed

PubMed Central

Lazarevic, Vladimir; Hörstedt, Ann-Sofi; Hagberg, Oskar; Höglund, Martin

2012-01-01

Population-based registries may provide data complementary to that from basic science and clinical intervention studies, all of which are essential for establishing recommendations for the management of patients in the real world. The same quality criteria apply for the evidence-based label, and both high representation and good data quality are crucial in registry studies. Registries with high coverage of the target population reduce the impact of selection on outcome and the subsequent problem with extrapolating data to nonstudied populations. Thus, data useful for clinical decision in situations not well covered by clinical studies can be provided. The potential clinical impact of data from population-based studies is exemplified with analyses from the Swedish Acute Leukemia Registry containing more than 3300 acute myeloid leukemia (AML) patients diagnosed between 1997 and 2006 with a median follow-up of 6.2 years on (1) the role of intensive combination chemotherapy for older patients with AML, (2) the impact of allogeneic stem cell transplantation on survival of younger patients with AML, and (3) the continuing problem with early deaths in acute promyelocytic leukemia. We also present the first Web-based dynamic graph showing the complex interaction between age, performance status, the proportion of patients given intensive treatment, early death rate, complete remission rate, use of allogeneic transplants, and overall survival in AML (non-AML). PMID:22383796

[New population curves in spanish extremely preterm neonates].

PubMed

García-Muñoz Rodrigo, F; García-Alix Pérez, A; Figueras Aloy, J; Saavedra Santana, P

2014-08-01

Most anthropometric reference data for extremely preterm infants used in Spain are outdated and based on non-Spanish populations, or are derived from small hospital-based samples that failed to include neonates of borderline viability. To develop gender-specific, population-based curves for birth weight, length, and head circumference in extremely preterm Caucasian infants, using a large contemporary sample size of Spanish singletons. Anthropometric data from neonates ≤ 28 weeks of gestational age were collected between January 2002 and December 2010 using the Spanish database SEN1500. Gestational age was estimated according to obstetric data (early pregnancy ultrasound). The data were analyzed with the SPSS.20 package, and centile tables were created for males and females using the Cole and Green LMS method. This study presents the first population-based growth curves for extremely preterm infants, including those of borderline viability, in Spain. A sexual dimorphism is evident for all of the studied parameters, starting at early gestation. These new gender-specific and population-based data could be useful for the improvement of growth assessments of extremely preterm infants in our country, for the development of epidemiological studies, for the evaluation of temporal trends, and for clinical or public health interventions seeking to optimize fetal growth. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Acute myeloid leukemia in the real world: why population-based registries are needed.

PubMed

Juliusson, Gunnar; Lazarevic, Vladimir; Hörstedt, Ann-Sofi; Hagberg, Oskar; Höglund, Martin

2012-04-26

Population-based registries may provide data complementary to that from basic science and clinical intervention studies, all of which are essential for establishing recommendations for the management of patients in the real world. The same quality criteria apply for the evidence-based label, and both high representation and good data quality are crucial in registry studies. Registries with high coverage of the target population reduce the impact of selection on outcome and the subsequent problem with extrapolating data to nonstudied populations. Thus, data useful for clinical decision in situations not well covered by clinical studies can be provided. The potential clinical impact of data from population-based studies is exemplified with analyses from the Swedish Acute Leukemia Registry containing more than 3300 acute myeloid leukemia (AML) patients diagnosed between 1997 and 2006 with a median follow-up of 6.2 years on (1) the role of intensive combination chemotherapy for older patients with AML, (2) the impact of allogeneic stem cell transplantation on survival of younger patients with AML, and (3) the continuing problem with early deaths in acute promyelocytic leukemia. We also present the first Web-based dynamic graph showing the complex interaction between age, performance status, the proportion of patients given intensive treatment, early death rate, complete remission rate, use of allogeneic transplants, and overall survival in AML (non-AML).

Phylogeography of the American woodcock (Scolopax minor): Are management units based on band recovery data reflected in genetically based management units?

USGS Publications Warehouse

Rhymer, J.M.; McAuley, D.G.; Ziel, H.L.

2005-01-01

Information on population connectivity throughout the annual cycle has become more crucial, because populations of many migratory birds are in decline. One such species is the American Woodcock (Scolopax minor), which inhabits early-successional forests in eastern North America. Although band recoveries have proved useful for dividing populations of this game bird species into an Eastern Region and Central Region for management purposes, these data do not provide enough detail to determine the breeding population of origin of birds recovered on stopover and wintering areas. To obtain more fine-scale data, we undertook a phylogeographic study of American Woodcock populations throughout their primary breeding range in the eastern United States and Canada using mitochondrial DNA (mtDNA) sequences from the hypervariable control region I (CRI) and ND6 gene. Despite high haplotype diversity, nucleotide diversity was low and there was no phylogeographic structure among American Woodcock populations across the species range, with birds from many states and provinces in both management regions sharing identical haplotypes. Results suggest recent or ongoing gene flow among populations, with asymmetric movement of birds between migration flyways. As has been demonstrated for several other avian species in North America, American Woodcock appear to have undergone a rapid population expansion following the late Pleistocene glacial retreat. Thus, a combination of historical demographic factors and recent or ongoing gene flow mask any population structure based on mtDNA that might accrue from philopatry to breeding areas observed in studies of marked birds.

Expansion of a globally pervasive grass occurs without substantial trait differences between home and away populations.

PubMed

Leifso, A; MacDougall, A S; Husband, B; Hierro, J L; Köchy, M; Pärtel, M; Peltzer, D A

2012-12-01

The global expansion of species beyond their ancestral ranges can derive from mechanisms that are trait-based (e.g., post-establishment evolved differences compared to home populations) or circumstantial (e.g., propagule pressure, with no trait-based differences). These mechanisms can be difficult to distinguish following establishment, but each makes unique predictions regarding trait similarity between ancestral ('home') and introduced ('away') populations. Here, we tested for trait-based population differences across four continents for the globally distributed grass Dactylis glomerata, to assess the possible role of trait evolution in its worldwide expansion. We used a common-environment glasshouse experiment to quantify trait differences among home and away populations, and the potential relevance of these differences for competitive interactions. Few significant trait differences were found among continents, suggesting minimal change during global expansion. All populations were polyploids, with similar foliar carbon:nitrogen ratios (a proxy for defense), chlorophyll content, and biomass. Emergence time and growth rate favored home populations, resulting in their competitive superiority over away populations. Small but significant trait differences among away populations suggest different introductory histories or local adaptive responses following establishment. In summary, the worldwide distribution of this species appears to have arisen from its pre-adapted traits promoting growth, and its repeated introduction with cultivation and intense propagule pressure. Global expansion can thus occur without substantial shifts in growth, reproduction, or defense. Rather than focusing strictly on the invader, invasion success may also derive from the traits found (or lacking) in the recipient community and from environmental context including human disturbance.

Congruent population structure inferred from dispersal behaviour and intensive genetic surveys of the threatened Florida scrub-jay (Aphelocoma cœrulescens)

USGS Publications Warehouse

Coulon, A.; Fitzpatrick, J.W.; Bowman, R.; Stith, B.M.; Makarewich, C.A.; Stenzler, L.M.; Lovette, I.J.

2008-01-01

The delimitation of populations, defined as groups of individuals linked by gene flow, is possible by the analysis of genetic markers and also by spatial models based on dispersal probabilities across a landscape. We combined these two complimentary methods to define the spatial pattern of genetic structure among remaining populations of the threatened Florida scrub-jay, a species for which dispersal ability is unusually well-characterized. The range-wide population was intensively censused in the 1990s, and a metapopulation model defined population boundaries based on predicted dispersal-mediated demographic connectivity. We subjected genotypes from more than 1000 individual jays screened at 20 microsatellite loci to two Bayesian clustering methods. We describe a consensus method for identifying common features across many replicated clustering runs. Ten genetically differentiated groups exist across the present-day range of the Florida scrub-jay. These groups are largely consistent with the dispersal-defined metapopulations, which assume very limited dispersal ability. Some genetic groups comprise more than one metapopulation, likely because these genetically similar metapopulations were sundered only recently by habitat alteration. The combined reconstructions of population structure based on genetics and dispersal-mediated demographic connectivity provide a robust depiction of the current genetic and demographic organization of this species, reflecting past and present levels of dispersal among occupied habitat patches. The differentiation of populations into 10 genetic groups adds urgency to management efforts aimed at preserving what remains of genetic variation in this dwindling species, by maintaining viable populations of all genetically differentiated and geographically isolated populations.

A guide to calculating habitat-quality metrics to inform conservation of highly mobile species

USGS Publications Warehouse

Bieri, Joanna A.; Sample, Christine; Thogmartin, Wayne E.; Diffendorfer, James E.; Earl, Julia E.; Erickson, Richard A.; Federico, Paula; Flockhart, D. T. Tyler; Nicol, Sam; Semmens, Darius J.; Skraber, T.; Wiederholt, Ruscena; Mattsson, Brady J.

2018-01-01

Many metrics exist for quantifying the relative value of habitats and pathways used by highly mobile species. Properly selecting and applying such metrics requires substantial background in mathematics and understanding the relevant management arena. To address this multidimensional challenge, we demonstrate and compare three measurements of habitat quality: graph-, occupancy-, and demographic-based metrics. Each metric provides insights into system dynamics, at the expense of increasing amounts and complexity of data and models. Our descriptions and comparisons of diverse habitat-quality metrics provide means for practitioners to overcome the modeling challenges associated with management or conservation of such highly mobile species. Whereas previous guidance for applying habitat-quality metrics has been scattered in diversified tracks of literature, we have brought this information together into an approachable format including accessible descriptions and a modeling case study for a typical example that conservation professionals can adapt for their own decision contexts and focal populations.Considerations for Resource ManagersManagement objectives, proposed actions, data availability and quality, and model assumptions are all relevant considerations when applying and interpreting habitat-quality metrics.Graph-based metrics answer questions related to habitat centrality and connectivity, are suitable for populations with any movement pattern, quantify basic spatial and temporal patterns of occupancy and movement, and require the least data.Occupancy-based metrics answer questions about likelihood of persistence or colonization, are suitable for populations that undergo localized extinctions, quantify spatial and temporal patterns of occupancy and movement, and require a moderate amount of data.Demographic-based metrics answer questions about relative or absolute population size, are suitable for populations with any movement pattern, quantify demographic processes and population dynamics, and require the most data.More real-world examples applying occupancy-based, agent-based, and continuous-based metrics to seasonally migratory species are needed to better understand challenges and opportunities for applying these metrics more broadly.

Assessing interethnic admixture using an X-linked insertion-deletion multiplex.

PubMed

Ribeiro-Rodrigues, Elzemar Martins; dos Santos, Ney Pereira Carneiro; dos Santos, Andrea Kely Campos Ribeiro; Pereira, Rui; Amorim, António; Gusmão, Leonor; Zago, Marco Antonio; dos Santos, Sidney Emanuel Batista

2009-01-01

In this study, a PCR multiplex was optimized, allowing the simultaneous analysis of 13 X-chromosome Insertion/deletion polymorphisms (INDELs). Genetic variation observed in Africans, Europeans, and Native Americans reveals high inter-population variability. The estimated proportions of X-chromosomes in an admixed population from the Brazilian Amazon region show a predominant Amerindian contribution (approximately 41%), followed by European (approximately 32%) and African (approximately 27%) contributions. The proportion of Amerindian contribution based on X-linked data is similar to the expected value based on mtDNA and Y-chromosome information. The accuracy for assessing interethnic admixture, and the high differentiation between African, European, and Native American populations, demonstrates the suitability of this INDEL set to measure ancestry proportions in three-hybrid populations, as it is the case of Latin American populations.

Clinical prediction and the idea of a population.

PubMed

Armstrong, David

2017-04-01

Using an analysis of the British Medical Journal over the past 170 years, this article describes how changes in the idea of a population have informed new technologies of medical prediction. These approaches have largely replaced older ideas of clinical prognosis based on understanding the natural histories of the underlying pathologies. The 19 th -century idea of a population, which provided a denominator for medical events such as births and deaths, was constrained in its predictive power by its method of enumerating individual bodies. During the 20 th century, populations were increasingly constructed through inferential techniques based on patient groups and samples seen to possess variable characteristics. The emergence of these new virtual populations created the conditions for the emergence of predictive algorithms that are used to foretell our medical futures.

Genetic polymorphisms of nine X-STR loci in four population groups from Inner Mongolia, China.

PubMed

Hou, Qiao-Fang; Yu, Bin; Li, Sheng-Bin

2007-02-01

Nine short tandem repeat (STR) markers on the X chromosome (DXS101, DXS6789, DXS6799, DXS6804, DXS7132, DXS7133, DXS7423, DXS8378, and HPRTB) were analyzed in four population groups (Mongol, Ewenki, Oroqen, and Daur) from Inner Mongolia, China, in order to learn about the genetic diversity, forensic suitability, and possible genetic affinities of the populations. Frequency estimates, Hardy-Weinberg equilibrium, and other parameters of forensic interest were computed. The results revealed that the nine markers have a moderate degree of variability in the population groups. Most heterozygosity values for the nine loci range from 0.480 to 0.891, and there are evident differences of genetic variability among the populations. A UPGMA tree constructed on the basis of the generated data shows very low genetic distance between Mongol and Han (Xi'an) populations. Our results based on genetic distance analysis are consistent with the results of earlier studies based on linguistics and the immigration history and origin of these populations. The minisatellite loci on the X chromosome studied here are not only useful in showing significant genetic variation between the populations, but also are suitable for human identity testing among Inner Mongolian populations.

Including the Group Quarters Population in the US Synthesized Population Database

PubMed Central

Chasteen, Bernadette M.; Wheaton, William D.; Cooley, Philip C.; Ganapathi, Laxminarayana; Wagener, Diane K.

2011-01-01

In 2005, RTI International researchers developed methods to generate synthesized population data on US households for the US Synthesized Population Database. These data are used in agent-based modeling, which simulates large-scale social networks to test how changes in the behaviors of individuals affect the overall network. Group quarters are residences where individuals live in close proximity and interact frequently. Although the Synthesized Population Database represents the population living in households, data for the nation’s group quarters residents are not easily quantified because of US Census Bureau reporting methods designed to protect individuals’ privacy. Including group quarters population data can be an important factor in agent-based modeling because the number of residents and the frequency of their interactions are variables that directly affect modeling results. Particularly with infectious disease modeling, the increased frequency of agent interaction may increase the probability of infectious disease transmission between individuals and the probability of disease outbreaks. This report reviews our methods to synthesize data on group quarters residents to match US Census Bureau data. Our goal in developing the Group Quarters Population Database was to enable its use with RTI’s US Synthesized Population Database in the Modeling of Infectious Diseases Agent Study. PMID:21841972

Cost-effectiveness of population based BRCA testing with varying Ashkenazi Jewish ancestry.

PubMed

Manchanda, Ranjit; Patel, Shreeya; Antoniou, Antonis C; Levy-Lahad, Ephrat; Turnbull, Clare; Evans, D Gareth; Hopper, John L; Macinnis, Robert J; Menon, Usha; Jacobs, Ian; Legood, Rosa

2017-11-01

Population-based BRCA1/BRCA2 testing has been found to be cost-effective compared with family history-based testing in Ashkenazi-Jewish women were >30 years old with 4 Ashkenazi-Jewish grandparents. However, individuals may have 1, 2, or 3 Ashkenazi-Jewish grandparents, and cost-effectiveness data are lacking at these lower BRCA prevalence estimates. We present an updated cost-effectiveness analysis of population BRCA1/BRCA2 testing for women with 1, 2, and 3 Ashkenazi-Jewish grandparents. Decision analysis model. Lifetime costs and effects of population and family history-based testing were compared with the use of a decision analysis model. 56% BRCA carriers are missed by family history criteria alone. Analyses were conducted for United Kingdom and United States populations. Model parameters were obtained from the Genetic Cancer Prediction through Population Screening trial and published literature. Model parameters and BRCA population prevalence for individuals with 3, 2, or 1 Ashkenazi-Jewish grandparent were adjusted for the relative frequency of BRCA mutations in the Ashkenazi-Jewish and general populations. Incremental cost-effectiveness ratios were calculated for all Ashkenazi-Jewish grandparent scenarios. Costs, along with outcomes, were discounted at 3.5%. The time horizon of the analysis is "life-time," and perspective is "payer." Probabilistic sensitivity analysis evaluated model uncertainty. Population testing for BRCA mutations is cost-saving in Ashkenazi-Jewish women with 2, 3, or 4 grandparents (22-33 days life-gained) in the United Kingdom and 1, 2, 3, or 4 grandparents (12-26 days life-gained) in the United States populations, respectively. It is also extremely cost-effective in women in the United Kingdom with just 1 Ashkenazi-Jewish grandparent with an incremental cost-effectiveness ratio of £863 per quality-adjusted life-years and 15 days life gained. Results show that population-testing remains cost-effective at the £20,000-30000 per quality-adjusted life-years and $100,000 per quality-adjusted life-years willingness-to-pay thresholds for all 4 Ashkenazi-Jewish grandparent scenarios, with ≥95% simulations found to be cost-effective on probabilistic sensitivity analysis. Population-testing remains cost-effective in the absence of reduction in breast cancer risk from oophorectomy and at lower risk-reducing mastectomy (13%) or risk-reducing salpingo-oophorectomy (20%) rates. Population testing for BRCA mutations with varying levels of Ashkenazi-Jewish ancestry is cost-effective in the United Kingdom and the United States. These results support population testing in Ashkenazi-Jewish women with 1-4 Ashkenazi-Jewish grandparent ancestry. Copyright © 2017 Elsevier Inc. All rights reserved.

Quality Dashboards: Technical and Architectural Considerations of an Actionable Reporting Tool for Population Management

PubMed Central

Olsha-Yehiav, Maya; Einbinder, Jonathan S.; Jung, Eunice; Linder, Jeffrey A.; Greim, Julie; Li, Qi; Schnipper, Jeffrey L.; Middleton, Blackford

2006-01-01

Quality Dashboards (QD) is a condition-specific, actionable web-based application for quality reporting and population management that is integrated into the Electronic Health Record (EHR). Using server-based graphic web controls in a .Net environment to construct Quality Dashboards allows customization of the reporting tool without the need to rely on commercial business intelligence tool. Quality Dashboards will improve patient care and quality outcomes as clinicians utilize the reporting tool for population management. PMID:17238671

Mapping cell populations in flow cytometry data for cross‐sample comparison using the Friedman–Rafsky test statistic as a distance measure

PubMed Central

Hsiao, Chiaowen; Liu, Mengya; Stanton, Rick; McGee, Monnie; Qian, Yu

2015-01-01

Abstract Flow cytometry (FCM) is a fluorescence‐based single‐cell experimental technology that is routinely applied in biomedical research for identifying cellular biomarkers of normal physiological responses and abnormal disease states. While many computational methods have been developed that focus on identifying cell populations in individual FCM samples, very few have addressed how the identified cell populations can be matched across samples for comparative analysis. This article presents FlowMap‐FR, a novel method for cell population mapping across FCM samples. FlowMap‐FR is based on the Friedman–Rafsky nonparametric test statistic (FR statistic), which quantifies the equivalence of multivariate distributions. As applied to FCM data by FlowMap‐FR, the FR statistic objectively quantifies the similarity between cell populations based on the shapes, sizes, and positions of fluorescence data distributions in the multidimensional feature space. To test and evaluate the performance of FlowMap‐FR, we simulated the kinds of biological and technical sample variations that are commonly observed in FCM data. The results show that FlowMap‐FR is able to effectively identify equivalent cell populations between samples under scenarios of proportion differences and modest position shifts. As a statistical test, FlowMap‐FR can be used to determine whether the expression of a cellular marker is statistically different between two cell populations, suggesting candidates for new cellular phenotypes by providing an objective statistical measure. In addition, FlowMap‐FR can indicate situations in which inappropriate splitting or merging of cell populations has occurred during gating procedures. We compared the FR statistic with the symmetric version of Kullback–Leibler divergence measure used in a previous population matching method with both simulated and real data. The FR statistic outperforms the symmetric version of KL‐distance in distinguishing equivalent from nonequivalent cell populations. FlowMap‐FR was also employed as a distance metric to match cell populations delineated by manual gating across 30 FCM samples from a benchmark FlowCAP data set. An F‐measure of 0.88 was obtained, indicating high precision and recall of the FR‐based population matching results. FlowMap‐FR has been implemented as a standalone R/Bioconductor package so that it can be easily incorporated into current FCM data analytical workflows. © 2015 International Society for Advancement of Cytometry PMID:26274018

Mapping cell populations in flow cytometry data for cross-sample comparison using the Friedman-Rafsky test statistic as a distance measure.

PubMed

Hsiao, Chiaowen; Liu, Mengya; Stanton, Rick; McGee, Monnie; Qian, Yu; Scheuermann, Richard H

2016-01-01

Flow cytometry (FCM) is a fluorescence-based single-cell experimental technology that is routinely applied in biomedical research for identifying cellular biomarkers of normal physiological responses and abnormal disease states. While many computational methods have been developed that focus on identifying cell populations in individual FCM samples, very few have addressed how the identified cell populations can be matched across samples for comparative analysis. This article presents FlowMap-FR, a novel method for cell population mapping across FCM samples. FlowMap-FR is based on the Friedman-Rafsky nonparametric test statistic (FR statistic), which quantifies the equivalence of multivariate distributions. As applied to FCM data by FlowMap-FR, the FR statistic objectively quantifies the similarity between cell populations based on the shapes, sizes, and positions of fluorescence data distributions in the multidimensional feature space. To test and evaluate the performance of FlowMap-FR, we simulated the kinds of biological and technical sample variations that are commonly observed in FCM data. The results show that FlowMap-FR is able to effectively identify equivalent cell populations between samples under scenarios of proportion differences and modest position shifts. As a statistical test, FlowMap-FR can be used to determine whether the expression of a cellular marker is statistically different between two cell populations, suggesting candidates for new cellular phenotypes by providing an objective statistical measure. In addition, FlowMap-FR can indicate situations in which inappropriate splitting or merging of cell populations has occurred during gating procedures. We compared the FR statistic with the symmetric version of Kullback-Leibler divergence measure used in a previous population matching method with both simulated and real data. The FR statistic outperforms the symmetric version of KL-distance in distinguishing equivalent from nonequivalent cell populations. FlowMap-FR was also employed as a distance metric to match cell populations delineated by manual gating across 30 FCM samples from a benchmark FlowCAP data set. An F-measure of 0.88 was obtained, indicating high precision and recall of the FR-based population matching results. FlowMap-FR has been implemented as a standalone R/Bioconductor package so that it can be easily incorporated into current FCM data analytical workflows. © The Authors. Published by Wiley Periodicals, Inc. on behalf of ISAC.

PM2.5 Population Exposure in New Delhi Using a Probabilistic Simulation Framework.

PubMed

Saraswat, Arvind; Kandlikar, Milind; Brauer, Michael; Srivastava, Arun

2016-03-15

This paper presents a Geographical Information System (GIS) based probabilistic simulation framework to estimate PM2.5 population exposure in New Delhi, India. The framework integrates PM2.5 output from spatiotemporal LUR models and trip distribution data using a Gravity model based on zonal data for population, employment and enrollment in educational institutions. Time-activity patterns were derived from a survey of randomly sampled individuals (n = 1012) and in-vehicle exposure was estimated using microenvironmental monitoring data based on field measurements. We simulated population exposure for three different scenarios to capture stay-at-home populations (Scenario 1), working population exposed to near-road concentrations during commutes (Scenario 2), and the working population exposed to on-road concentrations during commutes (Scenario 3). Simulated annual average levels of PM2.5 exposure across the entire city were very high, and particularly severe in the winter months: ∼200 μg m(-3) in November, roughly four times higher compared to the lower levels in the monsoon season. Mean annual exposures ranged from 109 μg m(-3) (IQR: 97-120 μg m(-3)) for Scenario 1, to 121 μg m(-3) (IQR: 110-131 μg m(-3)), and 125 μg m(-3) (IQR: 114-136 μ gm(-3)) for Scenarios 2 and 3 respectively. Ignoring the effects of mobility causes the average annual PM2.5 population exposure to be underestimated by only 11%.

Methods to estimate effective population size using pedigree data: Examples in dog, sheep, cattle and horse

PubMed Central

2013-01-01

Background Effective population sizes of 140 populations (including 60 dog breeds, 40 sheep breeds, 20 cattle breeds and 20 horse breeds) were computed using pedigree information and six different computation methods. Simple demographical information (number of breeding males and females), variance of progeny size, or evolution of identity by descent probabilities based on coancestry or inbreeding were used as well as identity by descent rate between two successive generations or individual identity by descent rate. Results Depending on breed and method, effective population sizes ranged from 15 to 133 056, computation method and interaction between computation method and species showing a significant effect on effective population size (P < 0.0001). On average, methods based on number of breeding males and females and variance of progeny size produced larger values (4425 and 356, respectively), than those based on identity by descent probabilities (average values between 93 and 203). Since breeding practices and genetic substructure within dog breeds increased inbreeding, methods taking into account the evolution of inbreeding produced lower effective population sizes than those taking into account evolution of coancestry. The correlation level between the simplest method (number of breeding males and females, requiring no genealogical information) and the most sophisticated one ranged from 0.44 to 0.60 according to species. Conclusions When choosing a method to compute effective population size, particular attention should be paid to the species and the specific genetic structure of the population studied. PMID:23281913

Coevolutionary dynamics in large, but finite populations

NASA Astrophysics Data System (ADS)

Traulsen, Arne; Claussen, Jens Christian; Hauert, Christoph

2006-07-01

Coevolving and competing species or game-theoretic strategies exhibit rich and complex dynamics for which a general theoretical framework based on finite populations is still lacking. Recently, an explicit mean-field description in the form of a Fokker-Planck equation was derived for frequency-dependent selection with two strategies in finite populations based on microscopic processes [A. Traulsen, J. C. Claussen, and C. Hauert, Phys. Rev. Lett. 95, 238701 (2005)]. Here we generalize this approach in a twofold way: First, we extend the framework to an arbitrary number of strategies and second, we allow for mutations in the evolutionary process. The deterministic limit of infinite population size of the frequency-dependent Moran process yields the adjusted replicator-mutator equation, which describes the combined effect of selection and mutation. For finite populations, we provide an extension taking random drift into account. In the limit of neutral selection, i.e., whenever the process is determined by random drift and mutations, the stationary strategy distribution is derived. This distribution forms the background for the coevolutionary process. In particular, a critical mutation rate uc is obtained separating two scenarios: above uc the population predominantly consists of a mixture of strategies whereas below uc the population tends to be in homogeneous states. For one of the fundamental problems in evolutionary biology, the evolution of cooperation under Darwinian selection, we demonstrate that the analytical framework provides excellent approximations to individual based simulations even for rather small population sizes. This approach complements simulation results and provides a deeper, systematic understanding of coevolutionary dynamics.

Risk of fragility fracture among patients with sarcoidosis: a population-based study 1976-2013-supplementary presentation.

PubMed

Ungprasert, P; Crowson, C S; Matteson, E L

2018-05-01

Incidence of fragility fracture of a population-based cohort of 345 patients with sarcoidosis was compared with age- and sex-matched comparators. The incidence of fragility fracture was higher among patients with sarcoidosis with a hazard ratio (HR) of 2.18.

45 CFR 402.31 - Determination of allocations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... based on the State's eligible legalized alien population, with 49 percent based upon the number of eligible legalized aliens in a State relative to the number of such aliens in all States, and 1 percent to States which have higher-than-average ratios of eligible legalized aliens to total population relative to...

45 CFR 402.31 - Determination of allocations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... based on the State's eligible legalized alien population, with 49 percent based upon the number of eligible legalized aliens in a State relative to the number of such aliens in all States, and 1 percent to States which have higher-than-average ratios of eligible legalized aliens to total population relative to...

45 CFR 402.31 - Determination of allocations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... based on the State's eligible legalized alien population, with 49 percent based upon the number of eligible legalized aliens in a State relative to the number of such aliens in all States, and 1 percent to States which have higher-than-average ratios of eligible legalized aliens to total population relative to...

USE OF COMMERCIAL TELEPHONE DIRECTORY FOR OBTAINING A POPULATION-BASED SAMPLE OF WOMEN OF REPRODUCTIVE AGE

EPA Science Inventory

Using Commercial Telephone Directories to Obtain a Population-Based Sample for Mail Survey of Women of Reproductive Age

Danelle T. Lobdella, Germaine M. Buckb, John M. Weinerc, Pauline Mendolaa

aUnited States Environmental Protection Agency, Office of Research and ...

Cancer Reporting: Timeliness Analysis and Process Reengineering

ERIC Educational Resources Information Center

Jabour, Abdulrahman M.

2016-01-01

Introduction: Cancer registries collect tumor-related data to monitor incident rates and support population-based research. A common concern with using population-based registry data for research is reporting timeliness. Data timeliness have been recognized as an important data characteristic by both the Centers for Disease Control and Prevention…

Development and assessment of plant-based synthetic odor baits for surveillance and control of Malaria vectors

USDA-ARS?s Scientific Manuscript database

Recent malaria vector control measures have considerably reduced indoor biting mosquito populations. However, reducing the outdoor biting populations remains a challenge because of the unavailability of appropriate lures to achieve this. This study sought to test the efficacy of plant-based syntheti...

A Population-Based Study of Preschoolers' Food Neophobia and Its Associations with Food Preferences

ERIC Educational Resources Information Center

Russell, Catherine Georgina; Worsley, Anthony

2008-01-01

Objective: This cross-sectional study was designed to investigate the relationships between food preferences, food neophobia, and children's characteristics among a population-based sample of preschoolers. Design: A parent-report questionnaire. Setting: Child-care centers, kindergartens, playgroups, day nurseries, and swimming centers. Subjects:…

Task Force on the Future of Military Health Care

DTIC Science & Technology

2007-12-01

Navigator. Service programs are supported by the Military Health System Population Health Portal (MHSPHP), a centralized, secure, web-based population...Congress on March 1, 2008.66 64 Air Force Medical Support Agency, Population Health Support Division. MHS Population Health Portal Methods. July 2007...HEDIS metrics using the MHS Population Health Portal and reporting in the service systems and the Tri- Service Business Planning tool. DoD has several

Population characteristics and the suppression of nonnative Burbot

USGS Publications Warehouse

Klein, Zachary B.; Quist, Michael C.; Rhea, Darren T.; Senecal, Anna C.

2016-01-01

Burbot Lota lota were illegally introduced into the Green River, Wyoming, drainage and have since proliferated throughout the system. Burbot in the Green River pose a threat to native species and to socially, economically, and ecologically important recreational fisheries. Therefore, managers of the Green River are interested in implementing a suppression program for Burbot. We collected demographic data on Burbot in the Green River (summer and autumn 2013) and used the information to construct an age-based population model (female-based Leslie matrix) to simulate the population-level response of Burbot to the selective removal of different age-classes. Burbot in the Green River grew faster, matured at relatively young ages, and were highly fecund compared with other Burbot populations within the species’ native distribution. The age-structured population model, in conjunction with demographic information, indicated that the Burbot population in the Green River could be expected to increase under current conditions. The model also indicated that the Burbot population in the Green River would decline once total annual mortality reached 58%. The population growth of Burbot in the Green River was most sensitive to age-0 and age-1 mortality. The age-structured population model indicated that an increase in mortality, particularly for younger age-classes, would result in the effective suppression of the Burbot population in the Green River.

Impact of in-Sewer Degradation of Pharmaceutical and Personal Care Products (PPCPs) Population Markers on a Population Model.

PubMed

O'Brien, Jake William; Banks, Andrew Phillip William; Novic, Andrew Joseph; Mueller, Jochen F; Jiang, Guangming; Ort, Christoph; Eaglesham, Geoff; Yuan, Zhiguo; Thai, Phong K

2017-04-04

A key uncertainty of wastewater-based epidemiology is the size of the population which contributed to a given wastewater sample. We previously developed and validated a Bayesian inference model to estimate population size based on 14 population markers which: (1) are easily measured and (2) have mass loads which correlate with population size. However, the potential uncertainty of the model prediction due to in-sewer degradation of these markers was not evaluated. In this study, we addressed this gap by testing their stability under sewer conditions and assessed whether degradation impacts the model estimates. Five markers, which formed the core of our model, were stable in the sewers while the others were not. Our evaluation showed that the presence of unstable population markers in the model did not decrease the precision of the population estimates providing that stable markers such as acesulfame remained in the model. However, to achieve the minimum uncertainty in population estimates, we propose that the core markers to be included in population models for other sites should meet two additional criteria: (3) negligible degradation in wastewater to ensure the stability of chemicals during collection; and (4) < 10% in-sewer degradation could occur during the mean residence time of the sewer network.

Genetic Diversity and Population Structure of Siberian apricot (Prunus sibirica L.) in China

PubMed Central

Li, Ming; Zhao, Zhong; Miao, Xingjun; Zhou, Jingjing

2014-01-01

The genetic diversity and population genetic structure of 252 accessions from 21 Prunus sibirica L. populations were investigated using 10 ISSR, SSR, and SRAP markers. The results suggest that the entire population has a relatively high level of genetic diversity, with populations HR and MY showing very high diversity. A low level of inter-population genetic differentiation and a high level of intra-population genetic differentiation was found, which is supported by a moderate level of gene flow, and largely attributable to the cross-pollination and self-incompatibility reproductive system. A STRUCTURE (model-based program) analysis revealed that the 21 populations can be divided into two main groups, mainly based on geographic differences and genetic exchanges. The entire wild Siberia apricot population in China could be divided into two subgroups, including 107 accessions in subgroup (SG) 1 and 147 accessions in SG 2. A Mantel test revealed a significant positive correlation between genetic and geographic distance matrices, and there was a very significant positive correlation among three marker datasets. Overall, we recommend a combination of conservation measures, with ex situ and in situ conservation that includes the construction of a core germplasm repository and the implement of in situ conservation for populations HR, MY, and ZY. PMID:24384840

Integrating data from multiple sources for insights into demographic processes: Simulation studies and proof of concept for hierarchical change-in-ratio models.

PubMed

Nilsen, Erlend B; Strand, Olav

2018-01-01

We developed a model for estimating demographic rates and population abundance based on multiple data sets revealing information about population age- and sex structure. Such models have previously been described in the literature as change-in-ratio models, but we extend the applicability of the models by i) using time series data allowing the full temporal dynamics to be modelled, by ii) casting the model in an explicit hierarchical modelling framework, and by iii) estimating parameters based on Bayesian inference. Based on sensitivity analyses we conclude that the approach developed here is able to obtain estimates of demographic rate with high precision whenever unbiased data of population structure are available. Our simulations revealed that this was true also when data on population abundance are not available or not included in the modelling framework. Nevertheless, when data on population structure are biased due to different observability of different age- and sex categories this will affect estimates of all demographic rates. Estimates of population size is particularly sensitive to such biases, whereas demographic rates can be relatively precisely estimated even with biased observation data as long as the bias is not severe. We then use the models to estimate demographic rates and population abundance for two Norwegian reindeer (Rangifer tarandus) populations where age-sex data were available for all harvested animals, and where population structure surveys were carried out in early summer (after calving) and late fall (after hunting season), and population size is counted in winter. We found that demographic rates were similar regardless whether we include population count data in the modelling, but that the estimated population size is affected by this decision. This suggest that monitoring programs that focus on population age- and sex structure will benefit from collecting additional data that allow estimation of observability for different age- and sex classes. In addition, our sensitivity analysis suggests that focusing monitoring towards changes in demographic rates might be more feasible than monitoring abundance in many situations where data on population age- and sex structure can be collected.

Cytochrome b gene reveals panmixia among Japanese Threadfin Bream, Nemipterus japonicus (Bloch, 1791) populations along the coasts of Peninsular Malaysia and provides evidence of a cryptic species.

PubMed

Lim, Hong-Chiun; Ahmad, Abu Talib; Nuruddin, Ahmad Adnan; Mohd Nor, Siti Azizah

2016-01-01

We evaluated genetic differentiation among ten presumed Japanese threadfin bream, Nemipterus japonicus populations along the coast of Peninsular Malaysia based on the partial sequence of the mitochondrial cytochrome b gene (982 bp). Genetic divergences (Kimura-2 parameter) ranged from 0.5% to 0.8% among nine of the ten populations while these nine populations were 4.4% to 4.6% diverged from the Kuala Besar population located at the Northeast coast. The constructed Neighbour Joining (NJ) phylogenetic trees based on haplotypes showed the Kuala Besar population forming an isolated cluster. The Analysis of Molecular Variance (AMOVA) of the ten populations a priori assigned into four regions, revealed that most of the variation occurred within population with a fairly low but significant level of regional differentiation (FST = 0.07, p < 0.05, FSC = 0.00, p > 0.05 and FCT = 0.07, p < 0.05) attributed to the Kuala Besar population. p Value after Bonferroni correction revealed that only pairwise FST values involving the Kuala Besar population with the other nine populations were significant. Thus, this study revealed that the N. japonicus populations off Peninsular Malaysia were panmictic. However, the Kuala Besar population, although morphologically identical was composed of a genetically discrete taxon from the rest. These findings are important contributions in formulating sustainable fishery management policies for this important fishery in Peninsular Malaysia.

Could the employment-based targeting approach serve Egypt in moving towards a social health insurance model?

PubMed

Shawky, S

2010-06-01

The current health insurance system in Egypt targets the productive population through an employment-based scheme bounded by a cost ceiling and focusing on curative care. Egypt Social Contract Survey data from 2005 were used to evaluate the impact of the employment-based scheme on health system accessibility and financing. Only 22.8% of the population in the productive age range (19-59 years) benefited from any health insurance scheme. The employment-based scheme covered 39.3% of the working population and was skewed towards urban areas, older people, females and the wealthier. It did not increase service utilization, but reduced out-of-pocket expenditure. Egypt should blend all health insurance schemes and adopt an innovative approach to reach universal coverage.

SUPPORTING PHYSICIANS' PRACTICE-BASED LEARNING AND IMPROVEMENT (PBLI) AND QUALITY IMPROVEMENT THROUGH EXPLORATION OF POPULATION-BASED MEDICAL DATA.

PubMed

Baumgart, Leigh A; Bass, Ellen J; Lyman, Jason A; Springs, Sherry; Voss, John; Hayden, Gregory F; Hellems, Martha A; Hoke, Tracey R; Schlag, Katharine A; Schorling, John B

2010-01-01

Participating in self-assessment activities may stimulate improvement in practice behaviors. However, it is unclear how best to support the development of self-assessment skills, particularly in the health care domain. Exploration of population-based data is one method to enable health care providers to identify deficiencies in overall practice behavior that can motivate quality improvement initiatives. At the University of Virginia, we are developing a decision support tool to integrate and present population-based patient data to health care providers related to both clinical outcomes and non-clinical measures (e.g., demographic information). By enabling users to separate their direct impact on clinical outcomes from other factors out of their control, we may enhance the self-assessment process.

SUPPORTING PHYSICIANS’ PRACTICE-BASED LEARNING AND IMPROVEMENT (PBLI) AND QUALITY IMPROVEMENT THROUGH EXPLORATION OF POPULATION-BASED MEDICAL DATA

PubMed Central

Baumgart, Leigh A.; Bass, Ellen J.; Lyman, Jason A.; Springs, Sherry; Voss, John; Hayden, Gregory F.; Hellems, Martha A.; Hoke, Tracey R.; Schlag, Katharine A.; Schorling, John B.

2011-01-01

Participating in self-assessment activities may stimulate improvement in practice behaviors. However, it is unclear how best to support the development of self-assessment skills, particularly in the health care domain. Exploration of population-based data is one method to enable health care providers to identify deficiencies in overall practice behavior that can motivate quality improvement initiatives. At the University of Virginia, we are developing a decision support tool to integrate and present population-based patient data to health care providers related to both clinical outcomes and non-clinical measures (e.g., demographic information). By enabling users to separate their direct impact on clinical outcomes from other factors out of their control, we may enhance the self-assessment process. PMID:21874123

NPP-VIIRS DNB-based reallocating subpopulations to mercury in Urumqi city cluster, central Asia

NASA Astrophysics Data System (ADS)

Zhou, X.; Feng, X. B.; Dai, W.; Li, P.; Ju, C. Y.; Bao, Z. D.; Han, Y. L.

2017-02-01

Accurate and update assignment of population-related environmental matters onto fine grid cells in oasis cities of arid areas remains challenging. We present the approach based on Suomi National Polar-orbiting Partnership (S-NPP) -Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) to reallocate population onto a regular finer surface. The number of potential population to the mercury were reallocated onto 0.1x0.1 km reference grid in Urumqi city cluster of China’s Xinjiang, central Asia. The result of Monte Carlo modelling indicated that the range of 0.5 to 2.4 million people was reliable. The study highlights that the NPP-VIIRS DNB-based multi-layered, dasymetric, spatial method enhances our abilities to remotely estimate the distribution and size of target population at the street-level scale and has the potential to transform control strategies for epidemiology, public policy and other socioeconomic fields.

Beyond genome-wide association studies: genetic heterogeneity and individual predisposition to cancer

PubMed Central

Galvan, Antonella; Ioannidis, John P.A.; Dragani, Tommaso A.

2010-01-01

Genome-wide association studies (GWAS) using population-based designs have identified many genetic loci associated with risk of a range of complex diseases including cancer; however, each locus exerts a very small effect and most heritability remains unexplained. Family-based pedigree studies have also suggested tentative loci linked to increased cancer risk, often characterized by pedigree-specificity. However, a comparison between the results of population-and those of family-based studies shows little concordance. Explanations for this unidentified genetic ‘dark matter’ of cancer include phenotype ascertainment issues, limited power, gene-gene and gene-environment interactions, population heterogeneity, parent-of-origin-specific effects, rare and unexplored variants. Many of these reasons converge towards the concept of genetic heterogeneity that might implicate hundreds of genetic variants in regulating cancer risk. Dissecting the dark matter is a challenging task. Further insights can be gained from both population association and pedigree studies. PMID:20106545

Climate-based models for West Nile Culex mosquito vectors in the Northeastern US

NASA Astrophysics Data System (ADS)

Gong, Hongfei; Degaetano, Arthur T.; Harrington, Laura C.

2011-05-01

Climate-based models simulating Culex mosquito population abundance in the Northeastern US were developed. Two West Nile vector species, Culex pipiens and Culex restuans, were included in model simulations. The model was optimized by a parameter-space search within biological bounds. Mosquito population dynamics were driven by major environmental factors including temperature, rainfall, evaporation rate and photoperiod. The results show a strong correlation between the timing of early population increases (as early warning of West Nile virus risk) and decreases in late summer. Simulated abundance was highly correlated with actual mosquito capture in New Jersey light traps and validated with field data. This climate-based model simulates the population dynamics of both the adult and immature mosquito life stage of Culex arbovirus vectors in the Northeastern US. It is expected to have direct and practical application for mosquito control and West Nile prevention programs.

Educational Attainment in the United States: 2015. Population Characteristics. Current Population Reports. P20-578

ERIC Educational Resources Information Center

Ryan, Camille L.; Bauman, Kurt

2016-01-01

This report provides a portrait of educational attainment in the United States based on data collected from the Current Population Survey (CPS). The report examines educational attainment of the adult population by demographic and social characteristics such as age, sex, race and Hispanic origin, and disability status, as well as differences in…

"Peer Review: Nonroad (NR) Updates to Population Growth, Compression Ignition (CI) Criteria, Toxic Emission Factors and Speciation Profiles"

EPA Science Inventory

This report focuses on the methodology for estimating growth in NR engine populations as used in the MOVES201X-NONROAD emission inventory model. MOVES NR growth rates start with base year engine populations and estimate growth in the populations of NR engines, while applying cons...

School Enrollment--Social and Economic Characteristics of Students: October 2003. Population Characteristics, P20-554

ERIC Educational Resources Information Center

Shin, Hyon B.

2005-01-01

This report highlights school enrollment trends of the population aged 3 and older and the social and economic characteristics of the large and diverse student population, based on data collected in the Current Population Survey (CPS) conducted by the Census Bureau in October 2003. (Contains 5 figures and 5 tables.)

Model-based scenario planning to develop climate change adaptation strategies for rare plant populations in grassland reserves

Treesearch

Laura Phillips-Mao; Susan M. Galatowitsch; Stephanie A. Snyder; Robert G. Haight

2016-01-01

Incorporating climate change into conservation decision-making at site and population scales is challenging due to uncertainties associated with localized climate change impacts and population responses to multiple interacting impacts and adaptation strategies. We explore the use of spatially explicit population models to facilitate scenario analysis, a conservation...

Population Changes in Planning District 8 and NVCC Enrollments: 2000-2010.

ERIC Educational Resources Information Center

Northern Virginia Community Coll., Annandale.

Based on population growth in Planning District 8, Northern Virginia Community College (NVCC) enrollment for the years 2000 and 2010 were estimated using two models--population-penetration and age-cohort--to estimate enrollments. According to the population-penetration model, it is estimated that during the fall 2000 semester there will be 38,557…

FROM MOLECULES TO POPULATIONS: USING POPULATION GENETICS TO ANSWER THE SO WHAT QUESTION

EPA Science Inventory

Important endpoints for ecological risk assessments are usually those that affect population or species persistence rather than individual-level responses. Nonetheless, ecological risk assessments are generally based on measures of individual-level responses. Extrapolation of i...

Population and performance analyses of four major populations with Illumina's FGx Forensic Genomics System.

PubMed

Churchill, Jennifer D; Novroski, Nicole M M; King, Jonathan L; Seah, Lay Hong; Budowle, Bruce

2017-09-01

The MiSeq FGx Forensic Genomics System (Illumina) enables amplification and massively parallel sequencing of 59 STRs, 94 identity informative SNPs, 54 ancestry informative SNPs, and 24 phenotypic informative SNPs. Allele frequency and population statistics data were generated for the 172 SNP loci included in this panel on four major population groups (Chinese, African Americans, US Caucasians, and Southwest Hispanics). Single-locus and combined random match probability values were generated for the identity informative SNPs. The average combined STR and identity informative SNP random match probabilities (assuming independence) across all four populations were 1.75E-67 and 2.30E-71 with length-based and sequence-based STR alleles, respectively. Ancestry and phenotype predictions were obtained using the ForenSeq™ Universal Analysis System (UAS; Illumina) based on the ancestry informative and phenotype informative SNP profiles generated for each sample. Additionally, performance metrics, including profile completeness, read depth, relative locus performance, and allele coverage ratios, were evaluated and detailed for the 725 samples included in this study. While some genetic markers included in this panel performed notably better than others, performance across populations was generally consistent. The performance and population data included in this study support that accurate and reliable profiles were generated and provide valuable background information for laboratories considering internal validation studies and implementation. Copyright © 2017 Elsevier B.V. All rights reserved.

Genetic structure of Xiphinema pachtaicum and X. index populations based on mitochondrial DNA variation.

PubMed

Gutiérrez-Gutiérrez, Carlos; Castillo, Pablo; Cantalapiedra-Navarrete, Carolina; Landa, Blanca B; Derycke, Sofie; Palomares-Rius, Juan E

2011-10-01

The dagger nematodes Xiphinema pachtaicum and X. index are two of the most widespread and frequently occurring Xiphinema spp. co-infesting vineyards and other crops and natural habitats worldwide. Sexual reproduction is rare in these species. The primary objective of this study was to determine the genetic structure of X. pachtaicum and X. index populations using eight and seven populations, respectively, from different "wine of denomination of origin (D.O.) zones" in Spain and Sardinia (Italy), by studying mitochondrial (cytochrome oxidase c subunit 1 or COI) and nuclear (D2-D3 expansion segments of 28S rDNA) markers. Both Xiphinema spp. showed low intraspecific divergence among COI sequences, ranging from 0.2% (1 base substitution) to 2.3% (10 substitutions) in X. pachtaicum and from 0.2% (1 base substitution) to 0.4% (2 substitutions) in X. index. Population genetic structure was strong for both species. Nevertheless, molecular differences among grapevine-growing areas were not significant, and intrapopulation diversity was very low. It is hypothesized that this genetic homogeneity in the nematode populations reflects their predominant parthenogenetic reproduction mode and low dispersal abilities. Our results also show that X. pachtaicum populations in Spain have possibly been established from two different populations of origin. Results also demonstrated that the two DNA regions studied are suitable diagnostic markers for X. index and X. pachtaicum.

Population Estimation in Singapore Based on Remote Sensing and Open Data

NASA Astrophysics Data System (ADS)

Guo, H.; Cao, K.; Wang, P.

2017-09-01

Population estimation statistics are widely used in government, commercial and educational sectors for a variety of purposes. With growing emphases on real-time and detailed population information, data users nowadays have switched from traditional census data to more technology-based data source such as LiDAR point cloud and High-Resolution Satellite Imagery. Nevertheless, such data are costly and periodically unavailable. In this paper, the authors use West Coast District, Singapore as a case study to investigate the applicability and effectiveness of using satellite image from Google Earth for extraction of building footprint and population estimation. At the same time, volunteered geographic information (VGI) is also utilized as ancillary data for building footprint extraction. Open data such as Open Street Map OSM could be employed to enhance the extraction process. In view of challenges in building shadow extraction, this paper discusses several methods including buffer, mask and shape index to improve accuracy. It also illustrates population estimation methods based on building height and number of floor estimates. The results show that the accuracy level of housing unit method on population estimation can reach 92.5 %, which is remarkably accurate. This paper thus provides insights into techniques for building extraction and fine-scale population estimation, which will benefit users such as urban planners in terms of policymaking and urban planning of Singapore.

Brief Report: Prevalence of Self-Injurious Behaviors among Children with Autism Spectrum Disorder--A Population-Based Study

ERIC Educational Resources Information Center

Soke, Gnakub N.; Rosenberg, Steven A.; Hamman, Richard F.; Fingerlin, Tasha; Robinson, Cordelia; Carpenter, Laura; Giarelli, Ellen; Lee, Li-Ching; Wiggins, Lisa D.; Durkin, Maureen S.; DiGuiseppi, Carolyn

2016-01-01

Self-injurious behaviors (SIB) have been reported in more than 30% of children with an autism spectrum disorder (ASD) in clinic-based studies. This study estimated the prevalence of SIB in a large population-based sample of children with ASD in the United States. A total of 8,065 children who met the surveillance case definition for ASD in the…

Comparison of Smoking, Drinking, and Marijuana Use between Students Present or Absent on the Day of a School-Based Survey

ERIC Educational Resources Information Center

Bovet, Pascal; Viswanathan, Bharathi; Faeh, David; Warren, Wick

2006-01-01

The aim of this population-based survey was to compare the prevalence of selected risk behaviors between students present or absent on the day of a school-based survey. The study population was a representative sample of all students of secondary schools in the Seychelles (Indian Ocean). Students absent on the day of the survey were traced and…

A Micro-Level Data-Calibrated Agent-Based Model: The Synergy between Microsimulation and Agent-Based Modeling.

PubMed

Singh, Karandeep; Ahn, Chang-Won; Paik, Euihyun; Bae, Jang Won; Lee, Chun-Hee

2018-01-01

Artificial life (ALife) examines systems related to natural life, its processes, and its evolution, using simulations with computer models, robotics, and biochemistry. In this article, we focus on the computer modeling, or "soft," aspects of ALife and prepare a framework for scientists and modelers to be able to support such experiments. The framework is designed and built to be a parallel as well as distributed agent-based modeling environment, and does not require end users to have expertise in parallel or distributed computing. Furthermore, we use this framework to implement a hybrid model using microsimulation and agent-based modeling techniques to generate an artificial society. We leverage this artificial society to simulate and analyze population dynamics using Korean population census data. The agents in this model derive their decisional behaviors from real data (microsimulation feature) and interact among themselves (agent-based modeling feature) to proceed in the simulation. The behaviors, interactions, and social scenarios of the agents are varied to perform an analysis of population dynamics. We also estimate the future cost of pension policies based on the future population structure of the artificial society. The proposed framework and model demonstrates how ALife techniques can be used by researchers in relation to social issues and policies.

Is a multivariate consensus representation of genetic relationships among populations always meaningful?

PubMed Central

Moazami-Goudarzi, K; Laloë, D

2002-01-01

To determine the relationships among closely related populations or species, two methods are commonly used in the literature: phylogenetic reconstruction or multivariate analysis. The aim of this article is to assess the reliability of multivariate analysis. We describe a method that is based on principal component analysis and Mantel correlations, using a two-step process: The first step consists of a single-marker analysis and the second step tests if each marker reveals the same typology concerning population differentiation. We conclude that if single markers are not congruent, the compromise structure is not meaningful. Our model is not based on any particular mutation process and it can be applied to most of the commonly used genetic markers. This method is also useful to determine the contribution of each marker to the typology of populations. We test whether our method is efficient with two real data sets based on microsatellite markers. Our analysis suggests that for closely related populations, it is not always possible to accept the hypothesis that an increase in the number of markers will increase the reliability of the typology analysis. PMID:12242255

Modelling hen harrier dynamics to inform human-wildlife conflict resolution: a spatially-realistic, individual-based approach.

PubMed

Heinonen, Johannes P M; Palmer, Stephen C F; Redpath, Steve M; Travis, Justin M J

2014-01-01

Individual-based models have gained popularity in ecology, and enable simultaneous incorporation of spatial explicitness and population dynamic processes to understand spatio-temporal patterns of populations. We introduce an individual-based model for understanding and predicting spatial hen harrier (Circus cyaneus) population dynamics in Great Britain. The model uses a landscape with habitat, prey and game management indices. The hen harrier population was initialised according to empirical census estimates for 1988/89 and simulated until 2030, and predictions for 1998, 2004 and 2010 were compared to empirical census estimates for respective years. The model produced a good qualitative match to overall trends between 1989 and 2010. Parameter explorations revealed relatively high elasticity in particular to demographic parameters such as juvenile male mortality. This highlights the need for robust parameter estimates from empirical research. There are clearly challenges for replication of real-world population trends, but this model provides a useful tool for increasing understanding of drivers of hen harrier dynamics and focusing research efforts in order to inform conflict management decisions.

Effects of trichloroethylene and perchloroethylene on wild rodents at Edwards Air Force Base, California, USA

USGS Publications Warehouse

Spring, Sarah E.; Miles, A. Keith; Anderson, Michael J.

2004-01-01

Effects of inhalation of volatilized trichloroethylene (TCE) or perchloroethylene (PCE) were assessed based on the health and population size of wild, burrowing mammals at Edwards Air Force Base (CA, USA). Organic soil-vapor concentrations were measured at three sites with aquifer contamination of TCE or PCE of 5.5 to 77 mg/L and at two uncontaminated reference sites. Population estimates of kangaroo rats (Dipodomys merriami and D. panamintinus) as well as hematology, blood chemistry, and histopathology of kangaroo rats and deer mice (Peromyscus maniculatus) were compared between contaminated and uncontaminated populations. Maximum soil-gas concentrations associated with groundwater contamination were less than 1.5 μl/L of TCE and 0.07 μl/L of PCE. Population estimates of kangaroo rats were similar at contaminated and reference sites. Hematology, blood chemistry, and histopathology of kangaroo rats and deer mice indicated no evidence of health effects caused by exposure. Trichloroethylene or PCE in groundwater and in related soil gas did not appear to reduce the size of small mammal populations or impair the health of individuals.

Modelling Hen Harrier Dynamics to Inform Human-Wildlife Conflict Resolution: A Spatially-Realistic, Individual-Based Approach

PubMed Central

Heinonen, Johannes P. M.; Palmer, Stephen C. F.; Redpath, Steve M.; Travis, Justin M. J.

2014-01-01

Individual-based models have gained popularity in ecology, and enable simultaneous incorporation of spatial explicitness and population dynamic processes to understand spatio-temporal patterns of populations. We introduce an individual-based model for understanding and predicting spatial hen harrier (Circus cyaneus) population dynamics in Great Britain. The model uses a landscape with habitat, prey and game management indices. The hen harrier population was initialised according to empirical census estimates for 1988/89 and simulated until 2030, and predictions for 1998, 2004 and 2010 were compared to empirical census estimates for respective years. The model produced a good qualitative match to overall trends between 1989 and 2010. Parameter explorations revealed relatively high elasticity in particular to demographic parameters such as juvenile male mortality. This highlights the need for robust parameter estimates from empirical research. There are clearly challenges for replication of real-world population trends, but this model provides a useful tool for increasing understanding of drivers of hen harrier dynamics and focusing research efforts in order to inform conflict management decisions. PMID:25405860

PopAffiliator: online calculator for individual affiliation to a major population group based on 17 autosomal short tandem repeat genotype profile.

PubMed

Pereira, Luísa; Alshamali, Farida; Andreassen, Rune; Ballard, Ruth; Chantratita, Wasun; Cho, Nam Soo; Coudray, Clotilde; Dugoujon, Jean-Michel; Espinoza, Marta; González-Andrade, Fabricio; Hadi, Sibte; Immel, Uta-Dorothee; Marian, Catalin; Gonzalez-Martin, Antonio; Mertens, Gerhard; Parson, Walther; Perone, Carlos; Prieto, Lourdes; Takeshita, Haruo; Rangel Villalobos, Héctor; Zeng, Zhaoshu; Zhivotovsky, Lev; Camacho, Rui; Fonseca, Nuno A

2011-09-01

Because of their sensitivity and high level of discrimination, short tandem repeat (STR) maker systems are currently the method of choice in routine forensic casework and data banking, usually in multiplexes up to 15-17 loci. Constraints related to sample amount and quality, frequently encountered in forensic casework, will not allow to change this picture in the near future, notwithstanding the technological developments. In this study, we present a free online calculator named PopAffiliator ( http://cracs.fc.up.pt/popaffiliator ) for individual population affiliation in the three main population groups, Eurasian, East Asian and sub-Saharan African, based on genotype profiles for the common set of STRs used in forensics. This calculator performs affiliation based on a model constructed using machine learning techniques. The model was constructed using a data set of approximately fifteen thousand individuals collected for this work. The accuracy of individual population affiliation is approximately 86%, showing that the common set of STRs routinely used in forensics provide a considerable amount of information for population assignment, in addition to being excellent for individual identification.

Genetic and morphological characterisation of the Ankole Longhorn cattle in the African Great Lakes region.

PubMed

Ndumu, Deo B; Baumung, Roswitha; Hanotte, Olivier; Wurzinger, Maria; Okeyo, Mwai A; Jianlin, Han; Kibogo, Harrison; Sölkner, Johann

2008-01-01

The study investigated the population structure, diversity and differentiation of almost all of the ecotypes representing the African Ankole Longhorn cattle breed on the basis of morphometric (shape and size), genotypic and spatial distance data. Twentyone morphometric measurements were used to describe the morphology of 439 individuals from 11 sub-populations located in five countries around the Great Lakes region of central and eastern Africa. Additionally, 472 individuals were genotyped using 15 DNA microsatellites. Femoral length, horn length, horn circumference, rump height, body length and fore-limb circumference showed the largest differences between regions. An overall FST index indicated that 2.7% of the total genetic variation was present among sub-populations. The least differentiation was observed between the two sub-populations of Mbarara south and Luwero in Uganda, while the highest level of differentiation was observed between the Mugamba in Burundi and Malagarasi in Tanzania. An estimated membership of four for the inferred clusters from a model-based Bayesian approach was obtained. Both analyses on distance-based and model-based methods consistently isolated the Mugamba sub-population in Burundi from the others.

Expanding syphilis testing: a scoping review of syphilis testing interventions among key populations.

PubMed

Ong, Jason J; Fu, Hongyun; Smith, M Kumi; Tucker, Joseph D

2018-05-01

Syphilis is an important sexually transmitted infection (STI). Despite inexpensive and effective treatment, few key populations receive syphilis testing. Innovative strategies are needed to increase syphilis testing among key populations. Areas covered: This scoping review focused on strategies to increase syphilis testing in key populations (men who have sex with men (MSM), sex workers, people who use drugs, transgender people, and incarcerated individuals). Expert commentary: We identified many promising syphilis testing strategies, particularly among MSM. These innovations are separated into diagnostic, clinic-based, and non-clinic based strategies. In terms of diagnostics, self-testing, dried blood spots, and point-of-care testing can decentralize syphilis testing. Effective syphilis self-testing pilots suggest the need for further attention and research. In terms of clinic-based strategies, modifying default clinical procedures can nudge physicians to more frequently recommend syphilis testing. In terms of non-clinic based strategies, venue-based screening (e.g. in correctional facilities, drug rehabilitation centres) and mobile testing units have been successfully implemented in a variety of settings. Integration of syphilis with HIV testing may facilitate implementation in settings where individuals have increased sexual risk. There is a strong need for further syphilis testing research and programs.

Proper Antibiotic Use in a Home-Based Primary Care Population Treated for Urinary Tract Infections.

PubMed

Gee, Megan E; Ford, James; Conway, Erin L; Ott, Michael C; Sellick, John A; Mergenhagen, Kari A

2018-02-01

To evaluate the trends associated with diagnosis and treatment of urinary tract infections (UTI) in a home-based primary care population of Veterans Health System patients from 2006 to 2015. Retrospective cohort study. Veterans Healthcare System. Home-based primary care patients treated for UTI from 2006 to 2015. None. Appropriate therapy was determined based on the McGeer criteria. Multivariate logistic regression was used to determine factors leading to appropriate UTI treatment. Of 366 available patients, 68 (18.6%) were tested for a UTI. Appropriate therapy occurred in 26% of patients. Allergy to any antibiotic increased the odds of appropriate treatment (odds ratio [OR] = 5.6, 95% confidence interval [CI] 1.5-23.2). Flank pain and increased urinary frequency also increased the likelihood of being treated appropriately (OR = 25.9, 95% CI 2.9-584.0 and OR = 4.49, 95% CI 0.99-21.2, respectively). Antibiotics were overused for treating UTIs in the homebound population. Patients with flank pain, increased urinary frequency, and antibiotic allergy were more likely to receive appropriate treatment. Pharmacists, therefore, have a viable opportunity to increase appropriate antibiotic prescribing in the home-based primary care population.

Methane emission from animals: A Global High-Resolution Data Base

NASA Astrophysics Data System (ADS)

Lerner, Jean; Matthews, Elaine; Fung, Inez

1988-06-01

We present a high-resolution global data base of animal population densities and associated methane emission. Statistics on animal populations from the Food and Agriculture Organization and other sources have been compiled. Animals were distributed using a 1° resolution data base of countries of the world and a 1° resolution data base of land use. The animals included are cattle and dairy cows, water buffalo, sheep, goats, camels, pigs, horses and caribou. Published estimates of methane production from each type of animal have been applied to the animal populations to yield a global distribution of annual methane emission by animals. There is large spatial variability in the distribution of animal populations and their methane emissions. Emission rates greater than 5000 kg CH4 km-2 yr-1 are found in small regions such as Bangladesh, the Benelux countries, parts of northern India, and New Zealand. Of the global annual emission of 75.8 Tg CH4 for 1984, about 55% is concentrated between 25°N and 55°N, a significant contribution to the observed north-south gradient of atmospheric methane concentration. A magnetic tape of the global data bases is available from the authors.

Genetic diversity and population structure inferred from the partially duplicated genome of domesticated carp, Cyprinus carpio L.

PubMed

David, Lior; Rosenberg, Noah A; Lavi, Uri; Feldman, Marcus W; Hillel, Jossi

2007-01-01

Genetic relationships among eight populations of domesticated carp (Cyprinus carpio L.), a species with a partially duplicated genome, were studied using 12 microsatellites and 505 AFLP bands. The populations included three aquacultured carp strains and five ornamental carp (koi) variants. Grass carp (Ctenopharyngodon idella) was used as an outgroup. AFLP-based gene diversity varied from 5% (grass carp) to 32% (koi) and reflected the reasonably well understood histories and breeding practices of the populations. A large fraction of the molecular variance was due to differences between aquacultured and ornamental carps. Further analyses based on microsatellite data, including cluster analysis and neighbor-joining trees, supported the genetic distinctiveness of aquacultured and ornamental carps, despite the recent divergence of the two groups. In contrast to what was observed for AFLP-based diversity, the frequency of heterozygotes based on microsatellites was comparable among all populations. This discrepancy can potentially be explained by duplication of some loci in Cyprinus carpio L., and a model that shows how duplication can increase heterozygosity estimates for microsatellites but not for AFLP loci is discussed. Our analyses in carp can help in understanding the consequences of genotyping duplicated loci and in interpreting discrepancies between dominant and co-dominant markers in species with recent genome duplication.

Genetic diversity and population structure inferred from the partially duplicated genome of domesticated carp, Cyprinus carpio L.

PubMed Central

David, Lior; Rosenberg, Noah A; Lavi, Uri; Feldman, Marcus W; Hillel, Jossi

2007-01-01

Genetic relationships among eight populations of domesticated carp (Cyprinus carpio L.), a species with a partially duplicated genome, were studied using 12 microsatellites and 505 AFLP bands. The populations included three aquacultured carp strains and five ornamental carp (koi) variants. Grass carp (Ctenopharyngodon idella) was used as an outgroup. AFLP-based gene diversity varied from 5% (grass carp) to 32% (koi) and reflected the reasonably well understood histories and breeding practices of the populations. A large fraction of the molecular variance was due to differences between aquacultured and ornamental carps. Further analyses based on microsatellite data, including cluster analysis and neighbor-joining trees, supported the genetic distinctiveness of aquacultured and ornamental carps, despite the recent divergence of the two groups. In contrast to what was observed for AFLP-based diversity, the frequency of heterozygotes based on microsatellites was comparable among all populations. This discrepancy can potentially be explained by duplication of some loci in Cyprinus carpio L., and a model that shows how duplication can increase heterozygosity estimates for microsatellites but not for AFLP loci is discussed. Our analyses in carp can help in understanding the consequences of genotyping duplicated loci and in interpreting discrepancies between dominant and co-dominant markers in species with recent genome duplication. PMID:17433244

Caste- and ethnicity-based inequalities in HIV/AIDS-related knowledge gap: a case of Nepal.

PubMed

Atteraya, Madhu; Kimm, HeeJin; Song, In Han

2015-05-01

Caste- and ethnicity-based inequalities are major obstacles to achieving health equity. The authors investigated whether there is any association between caste- and ethnicity-based inequalities and HIV-related knowledge within caste and ethnic populations. They used the 2011 Nepal Demographic and Health Survey, a nationally represented cross-sectional study data set. The study sample consisted of 11,273 women between 15 and 49 years of age. Univariate and logistic regression models were used to examine the relationship between caste- and ethnicity-based inequalities and HIV-related knowledge. The study sample was divided into high Hindu caste (47.9 percent), "untouchable" caste (18.4 percent), and indigenous populations (33.7 percent). Within the study sample, the high-caste population was found to have the greatest knowledge of the means by which HIV is prevented and transmitted. After controlling for socioeconomic and demographic characteristics, untouchables were the least knowledgeable. The odds ratio for incomplete knowledge about transmission among indigenous populations was 1.27 times higher than that for high Hindu castes, but there was no significant difference in knowledge of preventive measures. The findings suggest the existence of a prevailing HIV knowledge gap. This in turn suggests that appropriate steps need to be implemented to convey complete knowledge to underprivileged populations.

Population structure and genotypic variation of Crataegus pontica inferred by molecular markers.

PubMed

Rahmani, Mohammad-Shafie; Shabanian, Naghi; Khadivi-Khub, Abdollah; Woeste, Keith E; Badakhshan, Hedieh; Alikhani, Leila

2015-11-01

Information about the natural patterns of genetic variability and their evolutionary bases are of fundamental practical importance for sustainable forest management and conservation. In the present study, the genetic diversity of 164 individuals from fourteen natural populations of Crataegus pontica K.Koch was assessed for the first time using three genome-based molecular techniques; inter-retrotransposon amplified polymorphism (IRAP); inter-simple sequence repeats (ISSR) and start codon targeted (SCoT) polymorphism. IRAP, ISSR and SCoT analyses yielded 126, 254 and 199 scorable amplified bands, respectively, of which 90.48, 93.37 and 83.78% were polymorphic. ISSR revealed efficiency over IRAP and SCoT due to high effective multiplex ratio, marker index and resolving power. The dendrograms based on the markers used and combined data divided individuals into three major clusters. The correlation between the coefficient matrices for the IRAP, ISSR and SCoT data was significant. A higher level of genetic variation was observed within populations than among populations based on the markers used. The lower divergence levels depicted among the studied populations could be seen as evidence of gene flow. The promotion of gene exchange will be very beneficial to conserve and utilize the enormous genetic variability. Copyright © 2015 Elsevier B.V. All rights reserved.

Prevalence of Latent Mycobacterium Tuberculosis Infection (LTBI) in Saudi Arabia; Population based survey.

PubMed

Balkhy, Hanan H; El Beltagy, Kamel; El-Saed, Aiman; Aljasir, Badr; Althaqafi, Abdulhakeem; Alothman, Adel F; Alshalaan, Mohammad; Al-Jahdali, Hamdan

2017-07-01

The annual risk of tuberculosis infection (ARTI) data in Saudi Arabia has not been updated since 1993. To estimate the prevalence of latent TB infection (LTBI) and ARTI in a population-based sample in Saudi Arabia using Tuberculin skin test (TST) and QuantiFERON TB Gold in tube (QFT-GIT) test. A population-based cross sectional study was conducted between July 2010 and March 2013. Participants were randomly selected from the population served by the primary healthcare centers of the Ministry of National Guard Health Affairs in Riyadh, Jeddah, Alhassa and Dammam, Saudi Arabia. A total of 1369 participants were included. The overall prevalence of LTBI was similar using TST and QFT-GIT (9.3% and 9.1% respectively, p=0.872) but stratified prevalence rates were variable in all sociodemographic groups except marital status. Additionally, the prevalence rates of LTBI using either test alone showed significant differences by several sociodemographic and behavioral characteristics. The overall ARTI was 0.36% using TST and 0.35% using QFT-GIT. We are reporting much lower estimates for the prevalence of LTBI and the ARTI in a population-based sample in Saudi Arabia relative to the data that have been used for more than two decades. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Hippocampal atrophy in people with memory deficits: results from the population-based IPREA study.

PubMed

Ferrarini, Luca; van Lew, Baldur; Reiber, Johan H C; Gandin, Claudia; Galluzzo, Lucia; Scafato, Emanuele; Frisoni, Giovanni B; Milles, Julien; Pievani, Michela

2014-07-01

Clinical studies have shown that hippocampal atrophy is present before dementia in people with memory deficits and can predict dementia development. The question remains whether this association holds in the general population. This is of interest for the possible use of hippocampal atrophy to screen population for preventive interventions. The aim of this study was to assess hippocampal volume and shape abnormalities in elderly adults with memory deficits in a cross-sectional population-based study. We included individuals participating in the Italian Project on the Epidemiology of Alzheimer Disease (IPREA) study: 75 cognitively normal individuals (HC), 31 individuals with memory deficits (MEM), and 31 individuals with memory deficits not otherwise specified (MEMnos). Hippocampal volumes and shape were extracted through manual tracing and the growing and adaptive meshes (GAMEs) shape-modeling algorithm. We investigated between-group differences in hippocampal volume and shape, and correlations with memory deficits. In MEM participants, hippocampal volumes were significantly smaller than in HC and were mildly associated with worse memory scores. Memory-associated shape changes mapped to the anterior hippocampus. Shape-based analysis detected no significant difference between MEM and HC, while MEMnos showed shape changes in the posterior hippocampus compared with HC and MEM groups. These findings support the discriminant validity of hippocampal volumetry as a biomarker of memory impairment in the general population. The detection of shape changes in MEMnos but not in MEM participants suggests that shape-based biomarkers might lack sensitivity to detect Alzheimer's-like pathology in the general population.

Reoperation Rates After Anterior Cervical Discectomy and Fusion for Cervical Spondylotic Radiculopathy and Myelopathy: A National Population-based Study.

PubMed

Park, Moon Soo; Ju, Young-Su; Moon, Seong-Hwan; Kim, Tae-Hwan; Oh, Jae Keun; Makhni, Melvin C; Riew, K Daniel

2016-10-15

National population-based cohort study. To compare the reoperation rates between cervical spondylotic radiculopathy and myelopathy in a national population of patients. There is an inherently low incidence of reoperation after surgery for cervical degenerative disease. Therefore, it is difficult to sufficiently power studies to detect differences between reoperation rates of different cervical diagnoses. National population-based databases provide large, longitudinally followed cohorts that may help overcome this challenge. We used the Korean Health Insurance Review and Assessment Service national database to select our study population. We included patients with the diagnosis of cervical spondylotic radiculopathy or myelopathy who underwent anterior cervical discectomy and fusion from January 2009 to June 2014. We separated patients into two groups based on diagnosis codes: cervical spondylotic radiculopathy or cervical spondylotic myelopathy. Age, sex, presence of diabetes, osteoporosis, associated comorbidities, number of operated cervical disc levels, and hospital types were considered potential confounding factors. The overall reoperation rate was 2.45%. The reoperation rate was significantly higher in patients with cervical spondylotic myelopathy than in patients with cervical radiculopathy (myelopathy: P = 0.0293, hazard ratio = 1.433, 95% confidence interval 1.037-1.981). Male sex, presence of diabetes or associated comorbidities, and hospital type were noted to be risk factors for reoperation. The reoperation rate after anterior cervical discectomy and fusion was higher for cervical spondylotic myelopathy than for cervical spondylotic radiculopathy in a national population of patients. 3.

Adapting Animal-Assisted Therapy Trials to Prison-Based Animal Programs.

PubMed

Allison, Molly; Ramaswamy, Megha

2016-09-01

Prison-based animal programs have shown promise when it comes to increased sociability, responsibility, and levels of patience for inmates who participate in these programs. Yet there remains a dearth of scientific research that demonstrates the impact of prison-based animal programs on inmates' physical and mental health. Trials of animal-assisted therapy interventions, a form of human-animal interaction therapy most often used with populations affected by depression/anxiety, mental illness, and trauma, may provide models of how prison-based animal program research can have widespread implementation in jail and prison settings, whose populations have high rates of mental health problems. This paper reviews the components of prison-based animal programs most commonly practiced in prisons today, presents five animal-assisted therapy case studies, evaluates them based on their adaptability to prison-based animal programs, and discusses the institutional constraints that act as barriers for rigorous prison-based animal program research implementation. This paper can serve to inform the development of a research approach to animal-assisted therapy that nurses and other public health researchers can use in working with correctional populations. © 2016 Wiley Periodicals, Inc.

Prevalence of autosomal dominant polycystic kidney disease in the European Union.

PubMed

Willey, Cynthia J; Blais, Jaime D; Hall, Anthony K; Krasa, Holly B; Makin, Andrew J; Czerwiec, Frank S

2017-08-01

Autosomal dominant polycystic kidney disease (ADPKD) is a leading cause of end-stage renal disease, but estimates of its prevalence vary by >10-fold. The objective of this study was to examine the public health impact of ADPKD in the European Union (EU) by estimating minimum prevalence (point prevalence of known cases) and screening prevalence (minimum prevalence plus cases expected after population-based screening). A review of the epidemiology literature from January 1980 to February 2015 identified population-based studies that met criteria for methodological quality. These examined large German and British populations, providing direct estimates of minimum prevalence and screening prevalence. In a second approach, patients from the 2012 European Renal Association‒European Dialysis and Transplant Association (ERA-EDTA) Registry and literature-based inflation factors that adjust for disease severity and screening yield were used to estimate prevalence across 19 EU countries (N = 407 million). Population-based studies yielded minimum prevalences of 2.41 and 3.89/10 000, respectively, and corresponding estimates of screening prevalences of 3.3 and 4.6/10 000. A close correspondence existed between estimates in countries where both direct and registry-derived methods were compared, which supports the validity of the registry-based approach. Using the registry-derived method, the minimum prevalence was 3.29/10 000 (95% confidence interval 3.27-3.30), and if ADPKD screening was implemented in all countries, the expected prevalence was 3.96/10 000 (3.94-3.98). ERA-EDTA-based prevalence estimates and application of a uniform definition of prevalence to population-based studies consistently indicate that the ADPKD point prevalence is <5/10 000, the threshold for rare disease in the EU. © The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA.

A systematic review of economic evaluations of population-based sodium reduction interventions.

PubMed

Hope, Silvia F; Webster, Jacqui; Trieu, Kathy; Pillay, Arti; Ieremia, Merina; Bell, Colin; Snowdon, Wendy; Neal, Bruce; Moodie, Marj

2017-01-01

To summarise evidence describing the cost-effectiveness of population-based interventions targeting sodium reduction. A systematic search of published and grey literature databases and websites was conducted using specified key words. Characteristics of identified economic evaluations were recorded, and included studies were appraised for reporting quality using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist. Twenty studies met the study inclusion criteria and received a full paper review. Fourteen studies were identified as full economic evaluations in that they included both costs and benefits associated with an intervention measured against a comparator. Most studies were modelling exercises based on scenarios for achieving salt reduction and assumed effects on health outcomes. All 14 studies concluded that their specified intervention(s) targeting reductions in population sodium consumption were cost-effective, and in the majority of cases, were cost saving. Just over half the studies (8/14) were assessed as being of 'excellent' reporting quality, five studies fell into the 'very good' quality category and one into the 'good' category. All of the identified evaluations were based on modelling, whereby inputs for all the key parameters including the effect size were either drawn from published datasets, existing literature or based on expert advice. Despite a clear increase in evaluations of salt reduction programs in recent years, this review identified relatively few economic evaluations of population salt reduction interventions. None of the studies were based on actual implementation of intervention(s) and the associated collection of new empirical data. The studies universally showed that population-based salt reduction strategies are likely to be cost effective or cost saving. However, given the reliance on modelling, there is a need for the effectiveness of new interventions to be evaluated in the field using strong study designs and parallel economic evaluations.

Prevalence and Factors Associated with the Use of Eye Care Services in South Korea: Korea National Health and Nutrition Examination Survey 2010-2012.

PubMed

Park, Yong Seok; Heo, Hwan; Ye, Byeong Jin; Suh, Young-Woo; Kim, Seung-Hyun; Park, Shin Hae; Lim, Key Hwan; Lee, Sung Jin; Park, Song Hee; Baek, Seung-Hee

2017-02-01

To estimate the factors and prevalence of eye care service utilization in the South Korean population. This cross-sectional, population-based study included data from 22,550 Koreans aged ≥5 years who participated in the Korea National Health and Nutrition Examination Survey from 2010 to 2012. For people aged 5 to 11 years (young children), information was based on self-reports of contact with eye care service in the past year; for people aged ≥12 years (older population), the information was based on the self-reported lifetime contact with eye care service. Univariate and multivariate logistic regression analyses of the complex sample survey data were performed. The prevalence of eye care service use in young children during the past year was 61.1% (95% confidence interval, 58.1%-64.1%), while that in the older population during their lifetime was 73.5%. Subjects aged 7 to 11 years were more likely to have had an eye examination in the past year than subjects aged 5 to 6 years (odds ratio, 3.83; 95% confidence interval, 2.37-6.19). Multivariate logistic regression analysis indicated that higher monthly household income, being a National Health Insurance holder, and having private health insurance were related to more frequent use of eye care services in young children. For the older population and women, those living in an urban area and those with a best-corrected visual acuity less than 20 / 40 in the worse-seeing eye were more likely to have had an eye examination during their lifetime. Low education level was associated with low lifetime use of eye care services in the older population. There are sociodemographic disparities with use of eye care services in South Korea. This population-based study provides information that is useful for determining different intervention programs based on sociodemographic disparities to promote eye care service utilization in South Korea.

Asthma exacerbation and proximity of residence to major roads: a population-based matched case-control study among the pediatric Medicaid population in Detroit, Michigan

PubMed Central

2011-01-01

Background The relationship between asthma and traffic-related pollutants has received considerable attention. The use of individual-level exposure measures, such as residence location or proximity to emission sources, may avoid ecological biases. Method This study focused on the pediatric Medicaid population in Detroit, MI, a high-risk population for asthma-related events. A population-based matched case-control analysis was used to investigate associations between acute asthma outcomes and proximity of residence to major roads, including freeways. Asthma cases were identified as all children who made at least one asthma claim, including inpatient and emergency department visits, during the three-year study period, 2004-06. Individually matched controls were randomly selected from the rest of the Medicaid population on the basis of non-respiratory related illness. We used conditional logistic regression with distance as both categorical and continuous variables, and examined non-linear relationships with distance using polynomial splines. The conditional logistic regression models were then extended by considering multiple asthma states (based on the frequency of acute asthma outcomes) using polychotomous conditional logistic regression. Results Asthma events were associated with proximity to primary roads with an odds ratio of 0.97 (95% CI: 0.94, 0.99) for a 1 km increase in distance using conditional logistic regression, implying that asthma events are less likely as the distance between the residence and a primary road increases. Similar relationships and effect sizes were found using polychotomous conditional logistic regression. Another plausible exposure metric, a reduced form response surface model that represents atmospheric dispersion of pollutants from roads, was not associated under that exposure model. Conclusions There is moderately strong evidence of elevated risk of asthma close to major roads based on the results obtained in this population-based matched case-control study. PMID:21513554

Isolation and Applications of Prostate Side Population Cells Based on Dye Cycle Violet Efflux

PubMed Central

Gangavarapu, Kalyan J.; Huss, Wendy J.

2011-01-01

This unit describes methods for the digestion of human prostate clinical specimens, dye cycle violet (DCV) staining procedure for the identification, isolation, and quantitation of radiolabeled dihydrotestosterone (DHT) retention of side population cells. The principle of the side population assay is based on differential efflux of DCV, a cell membrane permeable fluorescent dye, by cells with high ATP binding cassette (ABC) transporter activity. Cells with high ABC transporter activity efflux DCV and fall in the lower left quadrant of a flow cytograph are designated as “side population” cells. This unit emphasizes tissue digestion, DCV staining, flow settings for sorting side population cells and quantitation of radiolabeled DHT retention. PMID:21400686

Medical and pharmacy coverage decision making at the population level.

PubMed

Mohr, Penny E; Tunis, Sean R

2014-06-01

Medicare is one of the largest health care payers in the United States. As a result, its decisions about coverage have profound implications for patient access to care. In this commentary, the authors describe how Medicare used evidence on heterogeneity of treatment effects to make population-based decisions on health care coverage for implantable cardiac defibrillators. This case is discussed in the context of the rapidly expanding availability of comparative effectiveness research. While there is a potential tension between population-based and patient-centered decision making, the expanded diversity of populations and settings included in comparative effectiveness research can provide useful information for making more discerning and informed policy and clinical decisions.

Should we expect population thresholds for wildlife disease?

USGS Publications Warehouse

Lloyd-Smith, James O.; Cross, P.C.; Briggs, C.J.; Daugherty, M.; Getz, W.M.; Latto, J.; Sanchez, M.; Smith, A.; Swei, A.

2005-01-01

Host population thresholds for invasion or persistence of infectious disease are core concepts of disease ecology, and underlie on-going and controversial disease control policies based on culling and vaccination. Empirical evidence for these thresholds in wildlife populations has been sparse, however, though recent studies have narrowed this gap. Here we review the theoretical bases for population thresholds for disease, revealing why they are difficult to measure and sometimes are not even expected, and identifying important facets of wildlife ecology left out of current theories. We discuss strengths and weaknesses of selected empirical studies that have reported disease thresholds for wildlife, identify recurring obstacles, and discuss implications of our imperfect understanding of wildlife thresholds for disease control policy.

Population estimates of extended family structure and size.

PubMed

Garceau, Anne; Wideroff, Louise; McNeel, Timothy; Dunn, Marsha; Graubard, Barry I

2008-01-01

Population-based estimates of biological family size can be useful for planning genetic studies, assessing how distributions of relatives affect disease associations with family history and estimating prevalence of potential family support. Mean family size per person is estimated from a population-based telephone survey (n = 1,019). After multivariate adjustment for demographic variables, older and non-White respondents reported greater mean numbers of total, first- and second-degree relatives. Females reported more total and first-degree relatives, while less educated respondents reported more second-degree relatives. Demographic differences in family size have implications for genetic research. Therefore, periodic collection of family structure data in representative populations would be useful. Copyright 2008 S. Karger AG, Basel.

Faster Increases in Human Life Expectancy Could Lead to Slower Population Aging

PubMed Central

2015-01-01

Counterintuitively, faster increases in human life expectancy could lead to slower population aging. The conventional view that faster increases in human life expectancy would lead to faster population aging is based on the assumption that people become old at a fixed chronological age. A preferable alternative is to base measures of aging on people’s time left to death, because this is more closely related to the characteristics that are associated with old age. Using this alternative interpretation, we show that faster increases in life expectancy would lead to slower population aging. Among other things, this finding affects the assessment of the speed at which countries will age. PMID:25876033

Population structure of Angiostrongylus cantonensis (Nematoda: Metastrongylidae) in Thailand based on PCR-RAPD markers.

PubMed

Thaenkham, Urusa; Pakdee, Wallop; Nuamtanong, Supaporn; Maipanich, Wanna; Pubampen, Somchit; Sa-Nguankiat, Surapol; Komalamisra, Chalit

2012-05-01

Angiostrongylus cantonensis is the causative agent of angiostrongyliasis, which is widely distributed throughout the world. It can specifically infect many species of intermediate and definitive hosts. This study examined the genetic differentiation and population structure using the RAPD-PCR method of parasites obtained from 8 different geographical areas of Thailand. Based on 8 primers, high levels of genetic diversity and low levels of gene flow among populations were found. Using genetic distance and neighbor-joining dendrogram methods, A. cantonensis in Thailand could be divided into two groups with statistically significant genetic differentiation of the two populations. However, genotypic variations and haplotype relationships need to be further elucidated using other markers.

The rural bite in population pyramids: what are the implications for responsiveness of health systems in middle income countries?

PubMed Central

2014-01-01

Background Health services can only be responsive if they are designed to service the needs of the population at hand. In many low and middle income countries, the rate of urbanisation can leave the profile of the rural population quite different from the urban population. As a consequence, the kinds of services required for an urban population may be quite different from that required for a rural population. This is examined using data from the South East Asia Community Observatory in rural Malaysia and contrasting it with the national Malaysia population profile. Methods Census data were collected from 10,373 household and the sex and age of household members was recorded. Approximate Malaysian national age and sex profiles were downloaded from the US Census Bureau. The population pyramids, and the dependency and support ratios for the whole population and the SEACO sub-district population are compared. Results Based on the population profiles and the dependency ratios, the rural sub-district shows need for health services in the under 14 age group similar to that required nationally. In the older age group, however, the rural sub-district shows twice the need for services as the national data indicate. Conclusion The health services needs of an older population will tend towards chronic conditions, rather than the typically acute conditions of childhood. The relatively greater number of older people in the rural population suggest a very different health services mix need. Community based population monitoring provides critical information to inform health systems. PMID:25081203

Suicide by people in a community justice pathway: population-based nested case–control study

PubMed Central

King, Carlene; Senior, Jane; Webb, Roger T.; Millar, Tim; Piper, Mary; Pearsall, Alison; Humber, Naomi; Appleby, Louis; Shaw, Jenny

2015-01-01

The elevated risk of suicide in prison and after release is a well-recognised and serious problem. Despite this, evidence concerning community-based offenders' suicide risk is sparse. We conducted a population-based nested case–control study of all people in a community justice pathway in England and Wales. Our data show 13% of general population suicides were in community justice pathways before death. Suicide risks were highest among individuals receiving police cautions, and those having recent, or impending prosecution for sexual offences. Findings have implications for the training and practice of clinicians identifying and assessing suicidality, and offering support to those at elevated risk. PMID:26159602

Genetic structure of a unique admixed population: implications for medical research.

PubMed

Patterson, Nick; Petersen, Desiree C; van der Ross, Richard E; Sudoyo, Herawati; Glashoff, Richard H; Marzuki, Sangkot; Reich, David; Hayes, Vanessa M

2010-02-01

STATEMENT: In naming population groups, we think a chief aim is to use terms that the group members use themselves, or find familiar and comfortable. The terms used in this manuscript to describe populations are as historically correct as possible and are chosen so as not to offend any population group. Two of the authors (DCP and REvdR) belong to the Coloured population, with one of the authors (REvdR) having contributed extensively to current literature on the history of the Coloured people of South Africa and served as Vice-President of the South African Institute of Race Relations. According to the 2001 South African census (http://www.statssa.gov.za/census01/HTML/CInBrief/CIB2001.pdf), "Statistics South Africa continues to classify people by population group, in order to monitor progress in moving away from the apartheid-based discrimination of the past. However, membership of a population group is now based on self-perception and self-classification, not on a legal definition. Five options were provided on the questionnaire, Black African, Coloured, Indian or Asian, White and Other. Responses in the category 'Other' were very few and were therefore imputed". We have elected to use the term Bushmen rather than San to refer to the hunter-gatherer people of Southern Africa. Although they have no collective name for themselves, this decision was based on the term Bushmen (or Bossiesman) being the more familiar to the communities themselves, while the term San is the more accepted academic classification. Understanding human genetic structure has fundamental implications for understanding the evolution and impact of human diseases. In this study, we describe the complex genetic substructure of a unique and recently admixed population arising approximately 350 years ago as a direct result of European settlement in South Africa. Analysis was performed using over 900 000 genome-wide single nucleotide polymorphisms in 20 unrelated ancestry-informative marker selected Coloured individuals and made comparisons with historically predicted founder populations. We show that there is substantial genetic contribution from at least four distinct population groups: Europeans, South Asians, Indonesians and a population genetically close to the isiXhosa sub-Saharan Bantu. This is in good accord with the historical record. We briefly examine the implications of determining the genetic diversity of this population, not only for furthering understanding of human evolution out of Africa, but also for genome-wide association studies using admixture mapping. In conclusion, we define the genetic structure of a uniquely admixed population that holds great potential to advance genetic-based medical research.