Multi-pathogen serological survey of migratory caribou herds: A snapshot in time.

Pathogens can impact host survival, fecundity, and population dynamics even when no obvious disease is observed. Few baseline data on pathogen prevalence and diversity of caribou are available, which hampers our ability to track changes over time and evaluate impacts on caribou health. Archived blood samples collected from ten migratory caribou herds in Canada and two in Greenland were used to test for exposure to pathogens that have the potential to effect population productivity, are zoonotic or are emerging. Relationships between seroprevalence and individual, population, and other health parameters were also examined. For adult caribou, the highest overall seroprevalence was for alphaherpesvirus (49%, n = 722), pestivirus (49%, n = 572) and Neospora caninum (27%, n = 452). Lower seroprevalence was found for parainfluenza virus type 3 (9%, n = 708), Brucella suis (2%, n = 758), and Toxoplasma gondii (2%, n = 706). No animal tested positive for antibodies against West Nile virus (n = 418) or bovine respiratory syncytial virus (n = 417). This extensive multi-pathogen survey of migratory caribou herds provides evidence that caribou are exposed to pathogens that may have impacts on herd health and revealed potential interactions between pathogens as well as geographical differences in pathogen exposure that could be linked to the bio-geographical history of caribou. Caribou are a keystone species and the socio-economic cornerstone of many indigenous cultures across the North. The results from this study highlight the urgent need for a better understanding of pathogen diversity and the impact of pathogens on caribou health.

Contribution of Arctic seabird-colony ammonia to atmospheric particles and cloud-albedo radiative effect.

The Arctic region is vulnerable to climate change and able to affect global climate. The summertime Arctic atmosphere is pristine and strongly influenced by natural regional emissions, which have poorly understood climate impacts related to atmospheric particles and clouds. Here we show that ammonia from seabird-colony guano is a key factor contributing to bursts of newly formed particles, which are observed every summer in the near-surface atmosphere at Alert, Nunavut, Canada. Our chemical-transport model simulations indicate that the pan-Arctic seabird-influenced particles can grow by sulfuric acid and organic vapour condensation to diameters sufficiently large to promote pan-Arctic cloud-droplet formation in the clean Arctic summertime. We calculate that the resultant cooling tendencies could be large (about -0.5 W m-2 pan-Arctic-mean cooling), exceeding -1 W m-2 near the largest seabird colonies due to the effects of seabird-influenced particles on cloud albedo. These coupled ecological-chemical processes may be susceptible to Arctic warming and industrialization.

The Reference Image Database to Evaluate Response to therapy in lung cancer (RIDER) project: a resource for the development of change-analysis software.

Critical to the clinical evaluation of effective novel therapies for lung cancer is the early and accurate determination of tumor response, which requires an understanding of the sources of uncertainty in tumor measurement and subsequent attempts to minimize their effects on the assessment of the therapeutic agent. The Reference Image Database to Evaluate Response (RIDER) project seeks to develop a consensus approach to the optimization and benchmarking of software tools for the assessment of tumor response to therapy and to provide a publicly available database of serial images acquired during lung cancer drug and radiation therapy trials. Images of phantoms and patient images acquired under situations in which tumor size or biology is known to be unchanged also will be provided. The RIDER project will create standardized methods for benchmarking software tools to reduce sources of uncertainty in vital clinical assessments such as whether a specific tumor is responding to therapy.

Kampimodromus aberrans (Acari: Phytoseiidae) from the USA: morphological and molecular assessment of its density.

Morphological measurements and a mitochondrial molecular marker (COI) were used to identity specimens reported as Kampimodromus aberrans on hazelnut in the USA. Several species and populations of this genus were studied to assist with identification. Both data types showed that specimens from the USA differed from K. aberrans from other regions. USA specimens seem to belong to the same species as Kampimodromus specimens from France on hazelnut. These mites were morphologically similar to Kampimodromus coryli and K. corylosus, which according to the original descriptions, are distinguished by the presence or absence of a tooth on the movable digit of the chelicera, with K. coryli having one tooth and K. corylosus none. As chelicerae of Kampimodromus from hazelnut in the USA and France are toothless, they are assigned to the species K. corylosus. Studies showed that morphological characters traditionally used to identify Kampimodromus species, such as setal length, are of less value than other characters that are difficult to observe, such as the numbers of solenostomes and the presence of teeth on the movable digit of the chelicerae. Some synonyms are discussed.

NCI Cancer Imaging Program efforts and their application to non-conventional radionuclides.

The US National Institute of Health (NIH) National Cancer Institute's Cancer Imaging Program funds research in cancer imaging. The article describes funding initiatives, such as Requests for Application and Program Announcement, funding mechanisms such as the R01 and R21, the Institutes of the NIH that fund imaging research, the application process, the application review process, and on-line resources to assist applicants for research funding for non-conventional radionuclides for imaging and therapy.

Resistance gene analogues in sugarcane and sorghum and their association with quantitative trait loci for rust resistance.

Fifty-four different sugarcane resistance gene analogue (RGA) sequences were isolated, characterized, and used to identify molecular markers linked to major disease-resistance loci in sugarcane. Ten RGAs were identified from a sugarcane stem expressed sequence tag (EST) library; the remaining 44 were isolated from sugarcane stem, leaf, and root tissue using primers designed to conserved RGA motifs. The map location of 31 of the RGAs was determined in sugarcane and compared with the location of quantitative trait loci (QTL) for brown rust resistance. After 2 years of phenotyping, 3 RGAs were shown to generate markers that were significantly associated with resistance to this disease. To assist in the understanding of the complex genetic structure of sugarcane, 17 of the 31 RGAs were also mapped in sorghum. Comparative mapping between sugarcane and sorghum revealed syntenic localization of several RGA clusters. The 3 brown rust associated RGAs were shown to map to the same linkage group (LG) in sorghum with 2 mapping to one region and the third to a region previously shown to contain a major rust-resistance QTL in sorghum. These results illustrate the value of using RGAs for the identification of markers linked to disease resistance loci and the value of simultaneous mapping in sugarcane and sorghum.

Evaluation of prey-stage preference as an indicator of life-style type in phytoseiid mites.

Discriminant analysis (DA) models were developed and applied to examine the use of prey-stage preference (Tetranychus urticae Koch egg versus larval prey) in the classification of phytoseiid mites into life-style types. Prey-stage preferences and developmental times when preying on T. urticae, and relative ovipositional rates on six food categories were determined for four phytoseiid species occurring on apple in central and eastern Oregon, USA: Galendromus flumenis (Chant), Galendromus occidentalis (Nesbitt), Metaseiulus citri (Garman and McGregor) and Typhlodromus caudiglans Schuster. In terms of all three aspects studied, the phytoseiid species showed a consistent polarization of G. occidentalis < or = G. flumenis < or = T. caudiglans < M. citri. Specifically, G. occidentalis ('The Dalles' strain) had a significant preference for eggs, G. flumenis had no preference, and T. caudiglans and M. citri had significant preferences for larvae; G. occidentalis had the shortest developmental time, followed by G. flumenis and T. caudiglans, while M. citri had the longest developmental time; and diet breadth was most narrow for G. occidentalis and progressively broader from G. flumenis, T. caudiglans through M. citri, which was able to sustain oviposition on the broadest range of prey and pollens. Species were classified somewhat differently depending on which traits were considered in a given DA. Prey-stage preference was not included as an indicator in the parsimonious DA model when all species and all traits were considered, but in general this trait performed well as an indicator alone (single-trait DA) and somewhat improved the classifications of multitrait discriminant analyses.

Phytoseiid mites on unsprayed apple trees in Oregon, and other western states (USA): distributions, life-style types and relevance to commercial orchards.

In unsprayed apple trees in eastern Oregon, Galendromus flumenis (Chant), Galendromus occidentalis (Nesbitt), Typhlodromus caudiglans Schuster and Metaseiulus citri (Garman and McGregor) were common phytoseiid mites; common plant-feeding mites were the eriophyid, Aculus schlechtendali Nalepa, the brown mite, Bryobia rubrioculus (Scheuten) and Eotetranychus spp.; apple rust mites seemed to be the primary prey for phytoseiids; the spider mites, Tetranychus urticae Koch and Panonychus ulmi (Koch) were scarce except for a few local outbreaks; the stigmaeid Zetzellia mali (Ewing) was at 10% of sites and its densities were inversely related to phytoseiid densities; phytoseiids were absent at some sites, particularly at high elevations where winters are severe. In seven Oregon ecoregions, G. flumenis was often at lower elevations in valleys with moderate winters; T. caudiglans was often at higher elevations; G. occidentalis was often at intermediate elevations, in young trees, and near where pesticides were used; it dominated in unsprayed trees only in almost treeless, sage-covered areas; M. citri was usually in older apple trees near agriculture. In mixed phytoseiid populations, M. citri, a generalist, and G. occidentalis, a specialist, occurred more often than expected; G. occidentalis was mostly found with T. caudiglans, a generalist; G. flumenis, a generalist, occurred less with others, possibly because it competes with both specialists and generalists. Analyses of species' distributions with multiple regression and genetic models gave explanatory r2s of 0.019-0.318. Of 29 variables, altitude of site, intensity of agricultural management, tree age, plant types, and Z. mali levels helped explain phytoseiid species presence. In the western USA, G. flumenis dominated in middle-southern latitudes; T. caudiglans dominated in the north near the Canadian border; G. occidentalis dominated in middle latitudes in parts of Washington, Idaho, Montana, and Wyoming; M. citri was at a few sites in these four states. Distributional and independent variable data were used to predict species presence at sites in Oregon with a 70% success rate. We discuss phytoseiid life-style types, community dynamics, presence in organic/conventional orchards, and trends as more selective IPM methods are used in apple orchards.

Low-density releases of Neoseiulus fallacis provide for rapid dispersal and control of Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae) on apple seedlings.

Releases of Neoseiulus fallacis (Garman) at 1500--6000 per ha when prey were at 0.1-0.3 per leaf provided seasonal control of Tetranychus urticae Koch (all stages) at 1-2 per leaf in an apple seedling rootstock nursery. Predaceous mites (all stages) increased to 0.3-0.4 per leaf after releases and predator prey ratios of < or = 1:3-7 provided pest regulation thereafter. Such low-density releases were thought to be effective because multiple dispersal bouts allowed predators to locate widely distributed spider mites (on 2-6% of leaves). A random-diffusion model simulating predator dispersal (incorporating wind speed and direction parameters) adequately explained movement and pest control patterns. An upright, dense, uniform planting of apple seedlings was an effective producer and recipient for dispersing predators and these attributes seemed to explain why biological control was so effective. Low-density releases of N. fallacis for control of T. urticae are predicted to be less effective on other crops with less prominent profiles and soil coverage.

Resistance to Fiji disease in sugar cane: role of cultivar preference by planthopper vector Perkinsiella saccharicida (Homoptera: Delphacidae).

Fiji disease (FD) of sugar cane caused by Fiji disease virus (FDV) is transmitted by the planthopper Perkinsiella saccharicida Kirkaldy (Hemiptera Delphacidae). FD is effectively managed by using resistant cultivars, but whether the resistance is for the vector or for the virus is unknown. This knowledge would help develop a rapid and reliable glasshouse-based screening method for disease resistance. Sugar cane cultivars resistant, intermediate, and susceptible to FD were screened in a glasshouse, and the relationship between vector preferences and FD incidence was studied. Cultivar preference by nymphs increased with an increase in cultivar susceptibility to FD, but the relationship between adult preference and FD resistance was not significant. There was a positive correlation between the vector population and FD incidence, and the latent period for symptom expression declined with the increase in the vector populations. FD incidence in the glasshouse trial reflected the field-resistance status of sugar cane cultivars with known FD-resistance scores. The results suggest that resistance to FD in sugar cane is mediated by cultivar preference of the planthopper vector.

Biological control of spider mites on grape by phytoseiid mites (Acari: Tetranychidae, Phytoseiidae): emphasis on regional aspects.

Leaf samples were taken from 34 (1998) and 10 (1999) vineyards in five valleys in western Oregon to assess spider mite pests and biological control by predaceous phytoseiid mites. A leaf at a coordinate of every 10 m of border, 5 m into a vineyard, was taken to minimize edge effects; 20 leaves were taken at regular intervals from vineyard centers. Variables recorded at each site included grape variety and plant age, chemicals used, and vegetation next to vineyards. Sites were rated as occurring in agricultural versus riparian settings based on surrounding vegetation types. Multiple linear regressions and a computer genetic algorithm with an information content criterion were used to assess variables that may explain mite abundances. Typhlodromus pyri Scheuten was the dominant phytoseiid mite species and Tetranychus urticae Koch the dominant tetranychid mite species. High levels of T. urticae occurred when phytoseiid levels were low, and low levels of T. urticae were present when phytoseiid levels were high to moderate. T. urticae densities were higher in vineyards surrounded by agriculture, but phytoseiid levels did not differ between agricultural and riparian sites. Phytoseiids had higher densities on vineyard edges; T. urticae densities were higher in centers. Biological control success of pest mites was rated excellent in 11 of 44 vineyards, good in 27, and poor in only six sites. Predaceous mites appeared to be the principal agents regulating spider mites at low levels in sites where pesticides nontoxic to predators were used. Effects of surrounding vegetation, grape variety, growing region, and other factors on mites are discussed.

Plant-related factors influence the effectiveness of Neoseiulus fallacis (Acari: Phytoseiidae), a biological control agent of spider mites on landscape ornamental plants.

The predatory mite Neoseiulus fallacis (Garman) was evaluated as a biological control agent of herbivorous mites on outdoor-grown ornamental landscape plants. To elucidate factors that may affect predator efficiency, replicated tests were conducted on 30 ornamental plant cultivars that varied in relationship to their generalized morphology (e.g., conifers, shade trees, evergreen shrubs, deciduous shrubs, and herbaceous perennials), production method (potted or field grown), canopy density, and the prey species present on each. Plant morphological grouping and foliar density appeared to be the most influential factors in predicting successful biological control. Among plant morphological groups, N. fallacis was most effective on shrubs and herbaceous perennials and less effective on conifers and shade trees. N. fallacis was equally effective at controlling spider mites on containerized (potted) and field grown plants, and there was no difference in control of mites on plants with Tetranychus spp. versus those with Oligonychus or Schizotetranychus spp. Moderate to unsuccessful control of spider mites by N. fallacis occurred mostly on tall, vertical plants with sparse canopies. Acceptable spider mite control occurred in four large-scale releases of N. fallacis into production plantings of Abies procera, Thuja occidentalis 'Emerald', Malus rootstock, and Viburnum plicatum 'Newport'. These data suggest that N. fallacis can be an effective biological control agent of multiple spider mite species in a range of low-growing and selected higher growing ornamental plants.

Jerking in predaceous mites (Acari: Phytoseiidae) with emphasis on larvae.

Jerking, a behavior involving a pronounced and often repeated lunging of the body, was studied in larvae among seven species of phytoseiid mites, Euseius finlandicus, Galendromus occidentalis, Neoseiulus californicus, Neoseulus fallacis, Phytoseiulus macropilis, Phytoseiulus persimilis and Typhlodromus pyri, and in the nymphal stages of N. fallacis. This behavior was observed in larvae of six of the seven species and in all active immature stages of N. fallacis. Jerking was usually triggered by direct contact with a con- or heterospecific mite, although jerking occurred occasionally without direct contact in N. fallacis larvae. The larval jerking tendency (the mean fraction of contacts resulting in jerking) of a species was significantly correlated with a tendency to congregate with conspecifics. Congregated larvae often probed their immediate area and each other with the front legs, repeatedly jerking in response to contact with neighboring larvae. Species with larvae having higher jerking tendencies also jerked more repeatedly per jerking event. Among species, there was no consistent relationship between jerking tendency and larval age. Larvae of N. fallacis had a higher tendency to jerk than protonymphs and deutonymphs, and they had both the highest jerking and congregating tendencies among larvae of all species studied. An individual was more likely to jerk when approached by another mite than when it initiated contact, and when observed in N. fallacis larvae that initiated contact, jerking was sometimes aggressive. Jerking N. fallacis larvae experienced fewer and shorter periods of probing by the mouthparts and fewer attacks from cannibalistic adult females than anesthetized larvae that were unable to jerk.

Quantitative classification of life-style types in predaceous phytoseiid mites.

Classification of species into different functional groups based on biological criteria has been a difficult problem in ecology. The difficulty mainly arises because natural classification patterns are not necessarily mutually exclusive. The more group characteristics overlap, the more difficult it is to identify the membership of a species in the overlapping portions of any two groups. In this paper, we present an application of discriminant analysis by creating classification models from life history and morphological data for two specialist and two generalist life-styles type of predaceous phytoseiid mites. Two stages can be distinguished in our method: life-style group membership assignment and trait variable evaluation. We use a Bayesian framework to create a classifier system to locate or assign species within a mixture of trait distributions. The method assumes that a mixture of trait distributions can represent the multiple dimensions of biological data. The mixture is most evident near the boundaries between groups. Because of the complexity of analytical solution, an iterative method is used to estimate the unknown means, variances, and mixing proportion between groups. We also developed a criterion based on information theory to evaluate model performance with different combinations of input variables and different hypotheses. We present a working example of our proposed methods. We apply these methods to the problem of selecting key species for inoculative release and for classical introductions of biological pest control agents.

Species association among predaceous and phytophagous apple mites (Acari: Eriophyidae, Phytoseiidae, Stigmaeidae, Tetranychidae).

Predator-predator, predator-prey, and prey-prey associations among nine species of mites were studied in a plot of 100 'Red Delicious' apple (Malus pumila Miller) trees from 1990 to 1997. In 1990, seven-year-old trees were inoculated with Panonychus ulmi (Koch), Tetranychus urticae Koch (Acari: Tetranychidae) or both, and sprayed with azinphosmethyl (alone or plus endosulfan), or nothing. The species Zetzellia mali (Ewing) (Acari: Stigmaeidae), Amblyseius andersoni Chant (Acari: Phytoseiidae), Eotetranychus sp., Bryobia rubrioculus (Scheuten) (Acari: Tetranychidae), and Aculus schlechtendali Nalepa (Acari: Eriophyidae) were already present or immigrated into plots, and Galendromus occidentalis (Nesbitt) and Tvphlodromus pyri Scheuten (Acari: Phytoseiidae) were introduced. Yule's V association index was used to measure positive, neutral, or negative interspecific associations for each species pair, because of its robustness with spatially autocorrelated data. We found that pesticide and release treatments did not greatly affect the association results, but there were strong seasonal differences. Predator-predator associations were the strongest and most consistent, showing negative associations in the early and mid seasons, and neutral ones in late season. Negative associations of T pyri with other predators were the strongest, which is consistent with evidence that this mite can detect other predators on a leaf. Predatorprey seasonal associations were mixed, with some positive and others negative, with most significant associations occurring in the mid season. One prey-prey interaction was positive, again in mid season, most likely because of similar habitat preferences.

Future directions in small animal imaging.

The adaptation and development of imaging technologies for use in small animals has the potential to be a refinement with profound effects on how basic cancer research using animals is conducted. The authors describe how NCI funding is helping to advance research in this area.

National Cancer Institute initiative: Lung image database resource for imaging research.

Preliminary clinical studies suggest that spiral computed tomography (CT) of the lungs can improve early detection of lung cancer in high-risk individuals. More clinical studies are needed, however, before public health recommendations can be proposed for population-based screening. Spiral CT generates large-volume data sets and thus poses problems in terms of implementation of efficient and cost-effective screening methods. Image processing algorithms such as computer assisted diagnostic (CAD) methods have the potential to assist in lesion (eg, nodule) detection on spiral CT studies. CAD methods may also be used to characterize nodules by either assessing the stability or change in size of lesions based on evaluation of serial CT studies, or quantitatively measuring the temporal parameters related to contrast dynamics when using contrast material-enhanced CT studies. CAD methods therefore have the potential to enhance the sensitivity and specificity of spiral CT lung screening studies. Lung cancer screening studies now under investigation create an opportunity to develop an image database that will allow comparison and optimization of CAD algorithms. This database could serve as an important national resource for the academic and industrial research community that is currently involved in the development of CAD methods. The National Cancer Institute request for applications (RFA) (CA-01-001) has already been announced (April 2000) to establish and support a consortium of academic centers to develop this database, the consortium to be referred to as the Lung Image Database Consortium (LIDC). This RFA is now closed. Five academic sites have been selected to be members of the LIDC, the first meeting of this consortium is planned for spring of 2001, and a public meeting is to be held in 2002. This report is abstracted from the previously published RFA to serve as an example of how an initiative is developed by the National Cancer Institute to support a research resource. For specific details of the RFA, please access the following Internet site: http://www. nci.nih.gov/bip/NCI-DIPinisumm.htm#a11.

Labelling of Re-ABP with 188Re for bone pain palliation.

Etidronate and medronate have been labelled with technetium-99m (99mTc-HEDP, 99mTc-MDP) for bone scanning and, with rhenium-188 (188Re-HEDP) to palliate the pain resulting from bone metastases. The objective of this study was to label alendronate, ABP, a new bisphosphonate, with SnF2-reduced-188Re. The reagents for the 5 mg ABP kit were SnF2, KReO4 and gentisic acid at acid pH. The chemical, spectroscopic and microscopic characteristics, quality control, rat bone uptake of [188Re]Re-ABP and similarities with 99mTc-ABP are presented. We conclude that this is a promising new radiopharmaceutical for bone metastases pain palliation.

Phytoseiid dispersal at plant to regional levels: a review with emphasis on management of Neoseiulus fallacis in diverse agroecosystems.

Dispersal behaviors of phytoseiid and tetranychid mites are key factors in understanding predator-prey dynamics and biological control of pest mites at different spatial levels in agricultural and natural ecosystems. In this review, ambulatory and aerial dispersal of both mite groups are discussed at spatial levels of leaf, plant, crop and region. Emphasis is on dispersal of phytoseiids, and specifically, the specialist-predator, Neoseiulusfallacis (Garman), and two-spotted spider mite prey, Tetranychus urticae (Koch). Dispersal aspects that are discussed are ambulation on a leaf; plant or in a prey patch; aerial dispersal between plants; behavior and aerodynamics of aerial take-off; modeling vs. monitoring of dispersal distance; fates of dispersing mites that land on soil substrates; plants as take-off platforms and landing targets for dispersers; and regional dispersal patterns and integrated mite management.