bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immune response to an endotoxin challenge involves multiple immune parameters and is consistent among the annual-cycle stages of a free-living temperate zone bird
Authors: Hegemann Arne , Matson Kevin D. , Versteegh Maaike A. , Villegas Auxiliadora , Tieleman B. Irene 
Published: March 2013

Summary
Trade-offs between immune function and other physiological and behavioral processes are central in ecoimmunology, but one important problem is how to distinguish a reallocation of resources away from the immune system from a reallocation or redistribution within the immune system. While variation in baseline values of individual immune parameters is well established, studies in wild animals on multiple parameters during an immune response are lacking. It also remains to be tested if and how immune responses correlate with baseline values that vary e.g. over the course of an annual cycle. We studied immunological responses to an endotoxin challenge in skylarks (Alauda arvensis), a partial migrant bird breeding in temperate zones. We compared birds injected with the endotoxin LPS with un-injected controls, characterizing immunological responses with leukocyte profiles, titres of lytic enzymes and natural antibodies, and concentrations of haptoglobin and heat shock proteins. We did this in five annual-cycle stages to test if the response varied throughout the year. The endotoxin challenge affected 6 of 10 measured parameters. Lysis titers and proportions of heterophils increased; haptoglobin concentrations and proportions of lymphocytes, basophils and eosinophils decreased. The variable effects on different immune components demonstrate the complexity of an immune response. We found no evidence that the response differed between annual-cycle stages. The response was independent of baseline measures taken directly upon capture in the field, indicating that birds were facing no immunological ceiling when mounting an immune response. Values of five parameters collected under field conditions were significantly related to values taken under standardised lab conditions. We conclude that multiple parts of the immune system are modulated during an immunological response and that responses are not re-organised throughout the annual cycle.
Flight performance of western sandpipers Calidris mauri remains uncompromised when mounting an acute phase immune response
Authors: Nebel Silke , Buehler Deborah M. , MacMillan Alexander , Guglielmo Christopher G. 
Published: March 2013

Summary
Migratory birds have been implicated in the spread of some zoonotic diseases, but how well infected individuals can fly remains poorly understood. We used western sandpipers Calidris mauri to experimentally test whether flight is affected when long-distance migrants are mounting an immune response and whether migrants maintain immune defences during a flight in a wind tunnel. We measured five indicators of innate immunity in ‘flown-healthy’ birds (flying in a wind tunnel without mounting an immune response),’flown-sick’ birds (flying while mounting an acute phase response, which is part of induced innate immunity), and a non-flying control group. Voluntary flight duration did not differ between ‘flown-healthy’ and ‘flown-sick’ birds, indicating that mounting an acute phase response to simulated infection did not hamper an individual’s ability to fly for up to three hours. However, in comparison to ‘not flown’ birds bacterial killing ability of plasma was significantly reduced after flight in ‘flown-sick’ birds. In ‘flown-healthy’ birds, voluntary flight duration was positively correlated with bacterial killing ability and baseline haptoglobin concentration of the blood plasma measured 1 - 3 weeks before experimental flights, suggesting that high quality birds had strong immune systems and greater flight capacity. Our findings indicate that flight performance is not diminished by prior immune challenge, but that flight while mounting an acute phase response negatively affects other aspects of immune function. These findings have important implications for our understanding of the transmission of avian diseases, as they suggest that birds can still migrate while fighting an infection.
Correlation between miRNA-targeted-gene promoter methylation and miRNA regulation of target genes
Authors: Taguchi Y-h 
Published: March 2013

BackgroundmiRNA regulation of target genes and promoter methylation are known to be the primary mechanisms underlying the epigenetic regulation of gene expression. However, how these two processes cooperatively regulate gene expression has not been extensively studied. MethodsGene expression and promoter methylation profiles of 271 distinct human cell lines were obtained from gene expression omnibus. P-values that describe both miRNA-targeted-gene promoter methylaion and miRNA regulation of target genes were computed using the MiRaGE method proposed recently by the author.Results Significant changes in promoter methylation were associated with miRNA targeting. It was also found that miRNA-targeted-gene promoter hypomethylation was related to differential target gene expression; the genes with miRNA-targeted-gene promoter hypomethylation were downregulated during cell senescence and upregulated during cellular differentiation. Promoter hypomethylation was especially enhanced for genes targeted by miR-548 miRNAs, which are non-conserved, primate-specific miRNAs that are typically expressed at lower levels than the frequently investigated conserved miRNAs.ConclusionsIt was found that promoter methylation was affected by miRNA targeting. Furthermore, miRNA-targeted-gene promoter hypomethylation is suggested to facilitate gene regulation by miRNAs that are not strongly expressed (e.g., miR-548 miRNAs).
Chemotaxonomic studies of mesembrine-type alkaloids in Sceletium plant species
Authors: Patnala Srinivas , Kanfer Isadore 
Published: March 2013

Complementary medicines containing the succulent herb Sceletium are being sold without information regarding their phytochemical contents, which is essential for the quality control of medicines. Furthermore, several different Sceletium species exist and little has been reported on the alkaloidal identities and contents of the various species. We therefore conducted phytochemical investigations on six selected Sceletium specimens, identified on the basis of their venation pattern as either ‘emarcidum’ or ‘tortuosum’ type. The tortuosum type consisted of S. tortuosum, S. expansum and S. strictum, whereas the emarcidum type consisted of S. emarcidum, S. exalatum and S. rigidum. Analysis was conducted by high-performance liquid chromatography with UV and alkaloids were identified by online mass spectroscopy.
Calibration of an Herbicide Ballistic Technology (HBT) Helicopter Platform Targeting Miconia calvescens in Hawaii
Authors: Leary James J. K. , Gooding Jeremy , Chapman John , Radford Adam , Mahnken Brooke , Cox Linda J. 
Published: March 2013

AbstractMiconia (Miconia calvescens DC.) is a tropical tree species from South and Central America that is a highly invasive colonizer of Hawaii's forested watersheds. Elimination of satellite populations is critical to an effective containment strategy, but extreme topography limits accessibility to remote populations by helicopter operations only. Herbicide Ballistic Technology (HBT) is a novel weed control tool designed to pneumatically deliver encapsulated herbicide projectiles. It is capable of accurately treating miconia satellites within a 30 m range in either horizontal or vertical trajectories. Efficacy was examined for the encapsulated herbicide projectiles, each containing 199.4 mg ae triclopyr, when applied to miconia in 5-unit increments. Experimental calibrations of the HBT platform were recorded on a Hughes 500-D helicopter while conducting surveillance operations from November 2010 through October 2011 on the islands of Maui and Kauai. Search efficiency (min ha−1; n = 13, R2 = 0.933, P< 0.001) and target acquisition rate (plants hr−1, n = 13, R2 = 0.926, P< 0.001) displayed positive linear and logarithmic relationships, respectively, to plant target density. The search efficiency equation estimated target acquisition time at 25.1 sec and a minimum surveillance rate of 67.8 s ha−1 when no targets were detected. The maximum target acquisition rate for the HBT platform was estimated at 143 targets hr−1. An average mortality factor of 0.542 was derived from the product of detection efficacy (0.560) and operational treatment efficacy (0.972) in overlapping buffer areas generated from repeated flight segments (n = 5). This population reduction value was used in simulation models to estimate the expected costs for one- and multi-year satellite population control strategies for qualifying options in cost optimization and risk aversion. This is a first report on the performance of an HBT helicopter platform demonstrating the capability for immediate, rapid-response control of new satellite plant detections, while conducting aerial surveillance of incipient miconia populations.
Potential Ocean Dispersal of Cordgrass (Spartinaspp.) from Core Infestations
Authors: Morgan Vanessa H. , Sytsma Mark D. 
Published: March 2013

AbstractNonnativeSpartinaspecies (cordgrasses) are widely distributed along the West Coast of North America, but have not invaded all bays with susceptible habitat. We used drift cards to assess the patterns and rates of potentialSpartinapropagule dispersal by ocean currents from estuaries with significant populations of one or moreSpartinaspecies. Cards were released monthly for 1 yr from Willapa Bay, Washington; Humboldt Bay, California; and San Francisco Bay, California; with recovery information reported by volunteers. Recovery rates averaged 37% for all release sites. Cards were commonly recovered close to their bay of release but were repeatedly found hundreds of kilometers both north and south of their release location. Cards most generally traveled northward from the release sites. Cards from Humboldt and Willapa bays were commonly recovered along the British Columbia coast, particularly in the winter. Cards released from Humboldt Bay were found farthest from their release sites. One card from Humboldt Bay traveled 2,800 km to Kodiak Island, Alaska. The timing of seed production, combined with prevailing currents, puts bays currently uninfested bySpartinaat risk of repeated propagule loading by ocean currents. A coordinated coast-wide strategy for eradication of all nonnativeSpartinawill be critical to the success of individual bay-wide eradication efforts.
Invasive Pine Tree Effects on Northern Coastal Scrub Structure and Composition
Authors: Steers Robert J. , Fritzke Susan L. , Rogers Jen J. , Cartan James , Hacker Kaitlyn 
Published: March 2013

AbstractVegetation that becomes overtopped usually experiences a decrease in abundance or species richness. When an overtopping plant alters the physiognomy of the existing vegetation (e.g., trees invading a shrubland), ecosystem processes can also be dramatically altered. Worldwide, Monterey pine (Pinus radiata) cultivars have been planted in Mediterranean-like climates and are known to invade surrounding natural communities. Ecological impacts resulting from these invasions have been widely investigated; however, the effects from solitary pine trees on the vegetation they overtop are lacking. Furthermore, studies on the impact of P. radiata cultivars from the California floristic province, where P. radiata is native, do not exist. In coastal California, north of the present-day range of native P. radiata stands, cultivars of this species have invaded northern coastal scrub vegetation. To determine the impact of pine invasion on species richness and structure in this habitat, floristic surveys were conducted in 20 blocks that consisted of invaded and uninvaded plots. An invaded plot contained two subplots located under the canopy of an isolated pine tree, whereas a paired, uninvaded plot contained two subplots located in coastal scrub adjacent to each pine. Pine trees selected ranged in size from 2.8 to 119 cm (1.1 to 46.9 in) basal diameter. Our results demonstrate that understory native cover and species richness are negatively correlated with tree size. Understory exotic plant cover and richness of species other than P. radiata did not show any correlation with tree size, mainly because exotic plants had a very low abundance overall.
Using a Stable Isotope to Label Seeds and Seedlings of an Invasive Shrub, Lonicera maackii
Authors: Castellano Steven M. , Gorchov David L. 
Published: March 2013

AbstractSeed dispersal is a crucial process in most plant invasions, but is notoriously difficult to study. One technique to identify the maternal source of dispersed seeds and newly established seedlings is labeling with a stable isotope. We tested whether foliar application of 15N-labeled urea would result in sufficient 15N enrichment to discriminate among seeds and seedlings grown from those seeds of the invasive shrub Lonicera maackii (Amur honeysuckle). We subjected mature L. maackii to all combinations of three concentrations of 15N-labeled urea (0.025 g L−1 [0.003 oz gal−1], 0.20 g L−1, and a 0 g L−1 control) and three temporal treatments (one application in August, one application in September, and five applications spaced every three weeks from June through August). Seeds were collected September to November; some of these were analyzed for %15N and others allowed to germinate and grow into seedlings under two treatments (in potting mix in greenhouse and in woodlot soil outdoors). Seedlings were harvested midway through the next growing season. We found that seeds from plants subjected to the three different concentrations had significantly different %15N levels, and there was a significant interaction between concentration and temporal treatment: the highest seed %15N levels were from plants sprayed five times with 15N-labeled urea, and the second highest from plants sprayed once in September. Similar patterns in %15N levels were found in seedlings, except that those from the 0.025 g L−1 spray treatment were only distinguishable from controls for seedlings grown outdoors in woodlot soil. These findings demonstrate that a single foliar application of 15N in early September is sufficient to label both seeds and seedlings of this invasive shrub, enabling one to identify the source of field-collected seeds or seedlings. This provides a tool for studying patterns and processes in seed dispersal of Amur honeysuckle and potentially other invasive plants.
Seasonal Biomass and Starch Allocation of Common Reed (Phragmites australis) (Haplotype I) in Southern Alabama, USA
Authors: Wersal Ryan M. , Madsen John D. , Cheshier Joshua C. 
Published: March 2013

AbstractCommon reed (Phragmites australis) is a nonnative invasive perennial grass that is problematic in aquatic and riparian environments across the United States. Common reed often forms monotypic stands that displace native vegetation which provide food and cover for wildlife. To help maintain native habitats and manage populations of common reed in the United States, an understanding of its life history and starch allocation patterns are needed. Monthly biomass samples were harvested from sites throughout the Mobile River delta in southern Alabama, USA from January 2006 to December 2007 to quantify seasonal biomass and starch allocation patterns. Total biomass of common reed throughout the study was between 1375 and 3718 g m−2 depending on the season. Maximum aboveground biomass was 2200 ± 220 g m−2 in October of 2006 and 1302 ± 88 g m−2 in December of 2007. Maximum belowground biomass was seen in November of 2006 and 2007 with 1602 ± 233 and 1610 ± 517 g m−2 respectively. Biomass was related to ambient temperature, in that, as temperature decreased aboveground biomass (p = 0.05) decreased. Decreases in aboveground biomass were followed by an increase in belowground biomass (p < 0.01). Starch comprised 1 to 10% of aboveground biomass with peak temporary storage occurring in July and August 2006 and September to November of 2007. Belowground tissues stored the majority of starch for common reed regardless of the time of year. Overall, belowground tissues stored 5 to 20% of total starch for common reed with peak storage occurring in December 2006 and October 2007. Starch allocation to belowground tissues increased as temperatures decreased. Understanding seasonal life history patterns can provide information to guide management strategies by identifying the vulnerable points in biomass and starch reserves in common reed.
Use of a Native Matrix Species to Facilitate Understory Restoration in an Overbrowsed, Invaded Woodland
Authors: Martinez Joshua A. , Dornbush Mathew E. 
Published: March 2013

AbstractThe interactive effects of herbivory, exotic species, and other human-mediated changes to the biosphere are reducing species diversity and altering ecosystem services globally. In this study, we tested whether facilitation could be used as a management technique to restore a degraded northeast Wisconsin forest understory facing high white-tailed deer (Odocoileus virginianus) browse pressure and high abundance of the exotic herb garlic mustard [Alliaria petiolata(Bieb.) Cavara & Grande]. Specifically, we attempted to facilitate native understory restoration by planting or seeding native herbs into three different matrix densities of the native, browse-tolerant grass Virginia wildrye (Elymus virginicusL.), which were either protected from (fenced), or accessible to, deer browsing. Deer had minimal impacts onE. virginicusbut significantly reduced the cover, survival, and flower production of white snakeroot [Ageratina altissima(L.) King & H.E. Robins.] transplants, largely independent of the density ofE. virginicusplantings in open-access plots. In contrast, the richness and abundance of native-seeded species were not affected by deer access but were reduced by increasingE. virginicusdensities.Alliaria petiolatacover was significantly higher in plots accessible to deer but declined significantly with increasingE. virginicusplanting density in both open-access and fenced plots. These results were largely corroborated by results from an associated observational study, with the exception that naturalE. virginicusstands supported slightly higher native-species richness than did adjacent areas lackingE. virginicus. Thus, although we found little support that establishingE. virginicusfacilitated browse-susceptible native understory herbs during our short-term experimental study, restoredE. virginicussuccessfully established, thereby increasing native species cover and significantly reducing the cover of the exoticA. petiolata. We suggest the planting of browse-tolerant native species, such asE. virginicus, as a viable restoration technique in heavily browsed,A. petiolata–invaded woodlands.
Seed and Germination Biology ofDittrichia graveolens(Stinkwort)
Authors: Brownsey Rachel N. , Kyser Guy B. , DiTomaso Joseph M. 
Published: March 2013

AbstractUnderstanding seed characteristics and seedling establishment patterns is essential for the development of effective management strategies for invasive annual species.Dittrichia graveolens(stinkwort) has increased its range rapidly within California since 1995, yet its biology is not well understood, which has led to poorly timed management. In this study, seed viability, germination, longevity, and dormancy, as well as seedling emergence characteristics ofD. graveolenswere evaluated in field, greenhouse, and laboratory experiments in Davis, CA, over a 2-yr period (fall 2010 to summer 2012). In the laboratory, seed germination ofD. graveolensoccurred at a wide range of constant temperatures (12 to 34 C). Cumulative germination was comparable to total seed viability (80 to 95%) at optimal germination temperatures, indicating that primary (innate) dormancy is likely absent. The base temperature for germination was identified using a thermal time model: 6.5 C and 4 C for 2010 and 2011 seed populations, respectively. In the field, seedlings emerged from fall through spring following precipitation events. A very low percentage of seedlings (2.5%) emerged in the second year after planting. Equivalent seedling emergence was observed over a wide range of light conditions (100, 50, 27, and 9% of available sunlight) in a greenhouse experiment, indicating that seed germination is not limited by high or low light. Results from these seed experiments improve our understanding of the reproductive biology of this rapidly expanding exotic annual and provide valuable information for developing effective timing and longevity of management programs.
Genetic Identity and Diversity of Perennial Pepperweed (Lepidium latifolium) in Its Native and Invaded Ranges
Authors: Gaskin John F. , Schwarzländer Mark , Hinz Hariet L. , Williams Livy , Gerber Esther , Rector Brian G. , Zhang DaoYuan 
Published: March 2013

AbstractPerennial pepperweed is an invasive plant species in North America, native to temperate Eurasia and northern Africa. Effective biological control depends upon correct taxonomic identification. Therefore, we investigated morphological and genetic data (cpDNA sequences and amplified fragment length polymorphisms [AFLP]) in its native range, where the species is at times treated as multiple taxa (L. latifolium, L. affineandL. obtusum). We also analyzed genetic data to determine the number and distribution of haplotypes and genotypes in the invaded range. Using Bayesian analysis, we found three clusters of AFLP genotypes in the native range, but little correlation between these clusters and morphological characters used to distinguish taxa. Also, we found combinations of morphological character states within many native range plants that are incompatible with current species descriptions, offering no support for splittingL. latifoliumsensu lato into three species. In North America 97% of the genetic variation was among populations and there were only eight AFLP genotypes in 288 plants, suggesting few introductions or a severe bottleneck, and little or no creation of new genotypes since introduction. We found plants in the native range that are genetically similar (88 to 99%) to six of the eight invasive AFLP genotypes, suggesting that Kazakhstan and China are origins for much of the North American invasion.