Laser-induced extreme magnetic field in nanorod targets

NASA Astrophysics Data System (ADS)

Lécz, Zsolt; Andreev, Alexander

2018-03-01

The application of nano-structured target surfaces in laser-solid interaction has attracted significant attention in the last few years. Their ability to absorb significantly more laser energy promises a possible route for advancing the currently established laser ion acceleration concepts. However, it is crucial to have a better understanding of field evolution and electron dynamics during laser-matter interactions before the employment of such exotic targets. This paper focuses on the magnetic field generation in nano-forest targets consisting of parallel nanorods grown on plane surfaces. A general scaling law for the self-generated quasi-static magnetic field amplitude is given and it is shown that amplitudes up to 1 MT field are achievable with current technology. Analytical results are supported by three-dimensional particle-in-cell simulations. Non-parallel arrangements of nanorods has also been considered which result in the generation of donut-shaped azimuthal magnetic fields in a larger volume.

Spectroscopy of exotic hadrons formed from dynamical diquarks

NASA Astrophysics Data System (ADS)

Lebed, Richard F.

2017-12-01

The dynamical diquark picture asserts that exotic hadrons can be formed from widely separated colored diquark or triquark components. We use the Born-Oppenheimer (BO) approximation to study the spectrum of states thus constructed, both in the basis of diquark spins and in the basis of heavy quark-antiquark spins. We develop a compact notation for naming these states, and use the results of lattice simulations for hybrid mesons to predict the lowest expected BO potentials for both tetraquarks and pentaquarks. We then compare to the set of exotic candidates with experimentally determined quantum numbers, and find that all of them can be accommodated. Once decay modes are also considered, one can develop selection rules of both exact (JP C conservation) and approximate (within the context of the BO approximation) types and test their effectiveness. We find that the most appealing way to satisfy both sets of selection rules requires including additional low-lying BO potentials, a hypothesis that can be checked on the lattice.

Statistical model of exotic rotational correlations in emergent space-time

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

Hogan, Craig; Kwon, Ohkyung; Richardson, Jonathan

2017-06-06

A statistical model is formulated to compute exotic rotational correlations that arise as inertial frames and causal structure emerge on large scales from entangled Planck scale quantum systems. Noncommutative quantum dynamics are represented by random transverse displacements that respect causal symmetry. Entanglement is represented by covariance of these displacements in Planck scale intervals defined by future null cones of events on an observer's world line. Light that propagates in a nonradial direction inherits a projected component of the exotic rotational correlation that accumulates as a random walk in phase. A calculation of the projection and accumulation leads to exact predictionsmore » for statistical properties of exotic Planck scale correlations in an interferometer of any configuration. The cross-covariance for two nearly co-located interferometers is shown to depart only slightly from the autocovariance. Specific examples are computed for configurations that approximate realistic experiments, and show that the model can be rigorously tested.« less

OLD-FIELD SUCCESSIONAL DYNAMICS FOLLOWING INTENSIVE HERBIVORY

EPA Science Inventory

Community composition and successional patterns can be altered by disturbance and exotic species invasions. Our objective was to describe vegetation dynamics following cessation of severe disturbance, which was heavy grazing by cattle, in an old-field grassland subject to invasi...

One-dimensional sections of exotic spacetimes with superconducting circuits

NASA Astrophysics Data System (ADS)

Sabín, Carlos

2018-05-01

We introduce analogue quantum simulations of 1 + 1 dimensional sections of exotic 3 + 1 dimensional spacetimes, such as Alcubierre warp-drive spacetime, Gödel rotating universe and Kerr highly-rotating black hole metric. Suitable magnetic flux profiles along a SQUID array embedded in a superconducting transmission line allow to generate an effective spatiotemporal dependence in the speed of light, which is able to mimic the corresponding light propagation in a dimensionally-reduced exotic spacetime. In each case, we discuss the technical constraints and the links with possible chronology protection mechanisms and we find the optimal region of parameters for the experimental implementation.

Deformations of infinite-dimensional Lie algebras, exotic cohomology, and integrable nonlinear partial differential equations

NASA Astrophysics Data System (ADS)

Morozov, Oleg I.

2018-06-01

The important unsolved problem in theory of integrable systems is to find conditions guaranteeing existence of a Lax representation for a given PDE. The exotic cohomology of the symmetry algebras opens a way to formulate such conditions in internal terms of the PDE s under the study. In this paper we consider certain examples of infinite-dimensional Lie algebras with nontrivial second exotic cohomology groups and show that the Maurer-Cartan forms of the associated extensions of these Lie algebras generate Lax representations for integrable systems, both known and new ones.

OLD FIELD SUCCESSIONAL DYNAMICS FOLLOWING CESSATION OF CHRONIC DISTURBANCE

EPA Science Inventory

In grasslands dominated by warm-season grasses, community composition and successional patterns can be altered by disturbance and exotic species invasions. Our objective was to describe vegetation dynamics following cessation of a chronic disturbance (heavy grazing by cattle) in...

Modeling the fish community population dynamics and forecasting the eradication success of an exotic fish from an alpine stream

USGS Publications Warehouse

Laplanche, Christophe; Elger, Arnaud; Santoul, Frédéric; Thiede, Gary P.; Budy, Phaedra

2018-01-01

Management actions aimed at eradicating exotic fish species from riverine ecosystems can be better informed by forecasting abilities of mechanistic models. We illustrate this point with an example of the Logan River, Utah, originally populated with endemic cutthroat trout (Oncorhynchus clarkii utah), which compete with exotic brown trout (Salmo trutta). The coexistence equilibrium was disrupted by a large scale, experimental removal of the exotic species in 2009–2011 (on average, 8.2% of the stock each year), followed by an increase in the density of the native species. We built a spatially-explicit, reaction-diffusion model encompassing four key processes: population growth in heterogeneous habitat, competition, dispersal, and a management action. We calibrated the model with detailed long-term monitoring data (2001–2016) collected along the 35.4-km long river main channel. Our model, although simple, did a remarkable job reproducing the system steady state prior to the management action. Insights gained from the model independent predictions are consistent with available knowledge and indicate that the exotic species is more competitive; however, the native species still occupies more favorable habitat upstream. Dynamic runs of the model also recreated the observed increase of the native species following the management action. The model can simulate two possible distinct long-term outcomes: recovery or eradication of the exotic species. The processing of available knowledge using Bayesian methods allowed us to conclude that the chance for eradication of the invader was low at the beginning of the experimental removal (0.7% in 2009) and increased (20.5% in 2016) by using more recent monitoring data. We show that accessible mathematical and numerical tools can provide highly informative insights for managers (e.g., outcome of their conservation actions), identify knowledge gaps, and provide testable theory for researchers.

Self organization of exotic oil-in-oil phases driven by tunable electrohydrodynamics

PubMed Central

Varshney, Atul; Ghosh, Shankar; Bhattacharya, S.; Yethiraj, Anand

2012-01-01

Self organization of large-scale structures in nature - either coherent structures like crystals, or incoherent dynamic structures like clouds - is governed by long-range interactions. In many problems, hydrodynamics and electrostatics are the source of such long-range interactions. The tuning of electrostatic interactions has helped to elucidate when coherent crystalline structures or incoherent amorphous structures form in colloidal systems. However, there is little understanding of self organization in situations where both electrostatic and hydrodynamic interactions are present. We present a minimal two-component oil-in-oil model system where we can control the strength and lengthscale of the electrohydrodynamic interactions by tuning the amplitude and frequency of the imposed electric field. As a function of the hydrodynamic lengthscale, we observe a rich phenomenology of exotic structure and dynamics, from incoherent cloud-like structures and chaotic droplet dynamics, to polyhedral droplet phases, to coherent droplet arrays. PMID:23071902

Dynamic excitations in membranes induced by optical tweezers.

PubMed Central

Bar-Ziv, R; Moses, E; Nelson, P

1998-01-01

We present the phenomenology of transformations in lipid bilayers that are excited by laser tweezers. A variety of dynamic instabilities and shape transformations are observed, including the pearling instability, expulsion of vesicles, and more exotic ones, such as the formation of passages. Our physical picture of the laser-membrane interaction is based on the generation of tension in the bilayer and loss of surface area. Although tension is the origin of the pearling instability, it does not suffice to explain expulsion of vesicles, where we observe opening of giant pores and creeping motion of bilayers. We present a quantitative theoretical framework to understand most of the observed phenomenology. The main hypothesis is that lipid is pulled into the optical trap by the familiar dielectric effect, is disrupted, and finally is repackaged into an optically unresolvable suspension of colloidal particles. This suspension, in turn, can produce osmotic pressure and depletion forces, driving the observed transformations. PMID:9649388

Nonlocal Coulomb correlations in pure and electron-doped Sr2IrO4 : Spectral functions, Fermi surface, and pseudo-gap-like spectral weight distributions from oriented cluster dynamical mean-field theory

NASA Astrophysics Data System (ADS)

Martins, Cyril; Lenz, Benjamin; Perfetti, Luca; Brouet, Veronique; Bertran, François; Biermann, Silke

2018-03-01

We address the role of nonlocal Coulomb correlations and short-range magnetic fluctuations in the high-temperature phase of Sr2IrO4 within state-of-the-art spectroscopic and first-principles theoretical methods. Introducing an "oriented-cluster dynamical mean-field scheme", we compute momentum-resolved spectral functions, which we find to be in excellent agreement with angle-resolved photoemission spectra. We show that while short-range antiferromagnetic fluctuations are crucial to accounting for the electronic properties of Sr2IrO4 even in the high-temperature paramagnetic phase, long-range magnetic order is not a necessary ingredient of the insulating state. Upon doping, an exotic metallic state is generated, exhibiting cuprate-like pseudo-gap spectral properties, for which we propose a surprisingly simple theoretical mechanism.

Resource diversity and provenance underpin spatial patterns in functional diversity across native and exotic species.

PubMed

Méndez, Verónica; Wood, Jamie R; Butler, Simon J

2018-05-01

Functional diversity metrics are increasingly used to augment or replace taxonomic diversity metrics to deliver more mechanistic insights into community structure and function. Metrics used to describe landscape structure and characteristics share many of the same limitations as taxonomy-based metrics, particularly their reliance on anthropogenically defined typologies with little consideration of structure, management, or function. However, the development of alternative metrics to describe landscape characteristics has been limited. Here, we extend the functional diversity framework to characterize landscapes based on the diversity of resources available across habitats present. We then examine the influence of resource diversity and provenance on the functional diversities of native and exotic avian communities in New Zealand. Invasive species are increasingly prevalent and considered a global threat to ecosystem function, but the characteristics of and interactions between sympatric native and exotic communities remain unresolved. Understanding their comparative responses to environmental change and the mechanisms underpinning them is of growing importance in predicting community dynamics and changing ecosystem function. We use (i) matrices of resource use (species) and resource availability (habitats) and (ii) occurrence data for 62 native and 25 exotic species and 19 native and 13 exotic habitats in 2015 10 × 10 km quadrats to examine the relationship between native and exotic avian and landscape functional diversity. The numbers of species in, and functional diversities of, native and exotic communities were positively related. Each community displayed evidence of environmental filtering, but it was significantly stronger for exotic species. Less environmental filtering occurred in landscapes providing a more diverse combination of resources, with resource provenance also an influential factor. Landscape functional diversity explained a greater proportion of variance in native and exotic community characteristics than the number of habitat types present. Resource diversity and provenance should be explicitly accounted for when characterizing landscape structure and change as they offer additional mechanistic understanding of the links between environmental filtering and community structure. Manipulating resource diversity through the design and implementation of management actions could prove a powerful tool for the delivery of conservation objectives, be they to protect native species, control exotic species, or maintain ecosystem service provision.

Population dynamics of an invasive forest insect and associated natural enemies in the aftermath of invasion: implications for biological control

USDA-ARS?s Scientific Manuscript database

Understanding the population dynamics of exotic pests and associated natural enemies is important in developing sound management strategies in invaded forest ecosystems. The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an invasive phloem-feeding beetle that h...

Zero-bias photocurrent in ferromagnetic topological insulator.

PubMed

Ogawa, N; Yoshimi, R; Yasuda, K; Tsukazaki, A; Kawasaki, M; Tokura, Y

2016-07-20

Magnetic interactions in topological insulators cause essential modifications in the originally mass-less surface states. They offer a mass gap at the Dirac point and/or largely deform the energy dispersion, providing a new path towards exotic physics and applications to realize dissipation-less electronics. The nonequilibrium electron dynamics at these modified Dirac states unveil additional functions, such as highly efficient photon to spin-current conversion. Here we demonstrate the generation of large zero-bias photocurrent in magnetic topological insulator thin films on mid-infrared photoexcitation, pointing to the controllable band asymmetry in the momentum space. The photocurrent spectra with a maximal response to the intra-Dirac-band excitations can be a sensitive measure for the correlation between Dirac electrons and magnetic moments.

Facilitation and Competition among Invasive Plants: A Field Experiment with Alligatorweed and Water Hyacinth

PubMed Central

Wundrow, Emily J.; Carrillo, Juli; Gabler, Christopher A.; Horn, Katherine C.; Siemann, Evan

2012-01-01

Ecosystems that are heavily invaded by an exotic species often contain abundant populations of other invasive species. This may reflect shared responses to a common factor, but may also reflect positive interactions among these exotic species. Armand Bayou (Pasadena, TX) is one such ecosystem where multiple species of invasive aquatic plants are common. We used this system to investigate whether presence of one exotic species made subsequent invasions by other exotic species more likely, less likely, or if it had no effect. We performed an experiment in which we selectively removed exotic rooted and/or floating aquatic plant species and tracked subsequent colonization and growth of native and invasive species. This allowed us to quantify how presence or absence of one plant functional group influenced the likelihood of successful invasion by members of the other functional group. We found that presence of alligatorweed (rooted plant) decreased establishment of new water hyacinth (free-floating plant) patches but increased growth of hyacinth in established patches, with an overall net positive effect on success of water hyacinth. Water hyacinth presence had no effect on establishment of alligatorweed but decreased growth of existing alligatorweed patches, with an overall net negative effect on success of alligatorweed. Moreover, observational data showed positive correlations between hyacinth and alligatorweed with hyacinth, on average, more abundant. The negative effect of hyacinth on alligatorweed growth implies competition, not strong mutual facilitation (invasional meltdown), is occurring in this system. Removal of hyacinth may increase alligatorweed invasion through release from competition. However, removal of alligatorweed may have more complex effects on hyacinth patch dynamics because there were strong opposing effects on establishment versus growth. The mix of positive and negative interactions between floating and rooted aquatic plants may influence local population dynamics of each group and thus overall invasion pressure in this watershed. PMID:23119021

Facilitation and competition among invasive plants: a field experiment with alligatorweed and water hyacinth.

PubMed

Wundrow, Emily J; Carrillo, Juli; Gabler, Christopher A; Horn, Katherine C; Siemann, Evan

2012-01-01

Ecosystems that are heavily invaded by an exotic species often contain abundant populations of other invasive species. This may reflect shared responses to a common factor, but may also reflect positive interactions among these exotic species. Armand Bayou (Pasadena, TX) is one such ecosystem where multiple species of invasive aquatic plants are common. We used this system to investigate whether presence of one exotic species made subsequent invasions by other exotic species more likely, less likely, or if it had no effect. We performed an experiment in which we selectively removed exotic rooted and/or floating aquatic plant species and tracked subsequent colonization and growth of native and invasive species. This allowed us to quantify how presence or absence of one plant functional group influenced the likelihood of successful invasion by members of the other functional group. We found that presence of alligatorweed (rooted plant) decreased establishment of new water hyacinth (free-floating plant) patches but increased growth of hyacinth in established patches, with an overall net positive effect on success of water hyacinth. Water hyacinth presence had no effect on establishment of alligatorweed but decreased growth of existing alligatorweed patches, with an overall net negative effect on success of alligatorweed. Moreover, observational data showed positive correlations between hyacinth and alligatorweed with hyacinth, on average, more abundant. The negative effect of hyacinth on alligatorweed growth implies competition, not strong mutual facilitation (invasional meltdown), is occurring in this system. Removal of hyacinth may increase alligatorweed invasion through release from competition. However, removal of alligatorweed may have more complex effects on hyacinth patch dynamics because there were strong opposing effects on establishment versus growth. The mix of positive and negative interactions between floating and rooted aquatic plants may influence local population dynamics of each group and thus overall invasion pressure in this watershed.

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

Zhang, Bing-Bing; Liu, Jian; Wei, Xu

We investigate the transient photoexcited lattice dynamics in a layered perovskite Mott insulator Sr2IrO4 film by femtosecond X-ray diffraction using a laser plasma-based X-ray source. The ultrafast structural dynamics of Sr2IrO4 thin films are determined by observing the shift and broadening of (0012) Bragg diffraction after excitation by 1.5 eV and 3.0 eV pump photons for films with different thicknesses. The observed transient lattice response can be well interpreted as a distinct three-step dynamics due to the propagation of coherent acoustic phonons generated by photoinduced quasiparticles (QPs). Employing a normalized phonon propagation model, we found that the photoinduced angular shiftsmore » of the Bragg peak collapse into a universal curve after introducing normalizedn coordinates to account for different thicknesses and pump photon energies, pinpointing the origin of the lattice distortion and its early evolution. In addition, a transient photocurrent measurement indicates that the photoinduced QPs are charge neutral excitons. Mapping the phonon propagation and correlating its dynamics with the QP by ultrafast X-ray diffraction (UXRD) establish a powerful way to study electron-phonon coupling and uncover the exotic physics in strongly correlated systems under nonequilibrium conditions.« less

The generation of plate tectonics from mantle convection

NASA Astrophysics Data System (ADS)

Bercovici, David

2003-01-01

In the last decade, significant progress has been made toward understanding how plate tectonics is generated from mantle dynamics. A primary goal of plate-generation studies has been the development of models that allow the top cold thermal boundary layer of mantle convection, i.e. the lithosphere, to develop broad and strong plate-like segments separated by narrow, weak and rapidly deforming boundaries; ideally, such models also permit significant strike-slip (toroidal) motion, passive ridges (i.e. pulled rather than pried apart), and self-consistent initiation of subduction. A major outcome of work so far is that nearly all aspects of plate generation require lithospheric rheologies and shear-localizing feedback mechanisms that are considerably more exotic than rheologies typically used in simple fluid-dynamical models of mantle flow. The search for plate-generating behavior has taken us through investigations of the effects of shear weakening ('stick-slip') and viscoplastic rheologies, of melting at ridges and low-viscosity asthenospheres, and of grain-size dependent rheologies and damage mechanics. Many such mechanisms, either by themselves or in combination, have led to self-consistent fluid-mechanical models of mantle flow that are remarkably plate-like, which is in itself a major accomplishment. However, many other important problems remain unsolved, such as subduction intiation and asymmetry, temporal evolution of plate geometry, rapid changes in plate motion, and the Archaean initiation of the plate-tectonic mode of convection. This paper presents a brief review of progress made in the plate-generation problem over the last decade, and discusses unresolved issues and future directions of research in this important area.

Valuation of Endowment-Insurance Equity-Linked Contracts for Stocks with Exotic Dynamics

PubMed Central

2014-01-01

We consider the fair martingale prize of insurance contracts with benefit received either at the insurer's demise or at maturity. We show how to modify the dynamics of the underlying so as to incorporate the possibility that the traded stock has a strong support at some level. The resulting dynamics is integrated and the fair prize of several natural endowment-insurance contracts is obtained. PMID:24672305

Linear Collider Physics Resource Book for Snowmass 2001 - Part 3: Studies of Exotic and Standard Model Physics

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

Abe, T.; et al.

This Resource Book reviews the physics opportunities of a next-generation e+e- linear collider and discusses options for the experimental program. Part 3 reviews the possible experiments on that can be done at a linear collider on strongly coupled electroweak symmetry breaking, exotic particles, and extra dimensions, and on the top quark, QCD, and two-photon physics. It also discusses the improved precision electroweak measurements that this collider will make available.

Photoinduced coherent acoustic phonon dynamics inside Mott insulator Sr2IrO4 films observed by femtosecond X-ray pulses

NASA Astrophysics Data System (ADS)

Zhang, Bing-Bing; Liu, Jian; Wei, Xu; Sun, Da-Rui; Jia, Quan-Jie; Li, Yuelin; Tao, Ye

2017-04-01

We investigate the transient photoexcited lattice dynamics in a layered perovskite Mott insulator Sr2IrO4 film by femtosecond X-ray diffraction using a laser plasma-based X-ray source. The ultrafast structural dynamics of Sr2IrO4 thin films are determined by observing the shift and broadening of (0012) Bragg diffraction after excitation by 1.5 eV and 3.0 eV pump photons for films with different thicknesses. The observed transient lattice response can be well interpreted as a distinct three-step dynamics due to the propagation of coherent acoustic phonons generated by photoinduced quasiparticles (QPs). Employing a normalized phonon propagation model, we found that the photoinduced angular shifts of the Bragg peak collapse into a universal curve after introducing normalized coordinates to account for different thicknesses and pump photon energies, pinpointing the origin of the lattice distortion and its early evolution. In addition, a transient photocurrent measurement indicates that the photoinduced QPs are charge neutral excitons. Mapping the phonon propagation and correlating its dynamics with the QP by ultrafast X-ray diffraction (UXRD) establish a powerful way to study electron-phonon coupling and uncover the exotic physics in strongly correlated systems under nonequilibrium conditions.

Contemporary morphological diversification of passerine birds introduced to the Hawaiian archipelago.

PubMed

Mathys, Blake A; Lockwood, Julie L

2011-08-07

Species that have been introduced to islands experience novel and strong selection pressures after establishment. There is evidence that exotic species diverge from their native source populations; further, a few studies have demonstrated adaptive divergence across multiple exotic populations of a single species. Exotic birds provide a good study system, as they have been introduced to many locations worldwide, and we often know details concerning the propagule origin, time of introduction, and dynamics of establishment and dispersal within the introduced range. These data make them especially conducive to the examination of contemporary evolution. Island faunas have received intense scrutiny, therefore we have expectations concerning the patterns of diversification for exotic species. We examine six passerine bird species that were introduced to the Hawaiian archipelago less than 150 years ago. We find that five of these show morphological divergence among islands from the time since they were established. We demonstrate that some of this divergence cannot be accounted for by genetic drift, and therefore we must consider adaptive evolution to explain it. We also evaluate evolutionary divergence rates and find that these species are diverging at similar rates to those found in published studies of contemporary evolution in native species.

Population dynamics of an invasive forest insect and associated natural enemies in the aftermath of invasion: implications for biological control

Treesearch

Jian J. Duan; Leah S. Bauer; Kristopher J. Abell; Michael D. Ulyshen; Roy G. Van Driesche

2015-01-01

1. Understanding the population dynamics of exotic pests and associated natural enemies is important in developing sound management strategies in invaded forest ecosystems. The emerald ash borer (EAB) Agrilus planipennis Fairmaire is an invasive phloem-feeding beetle that has killed tens of millions of ash Fraxinus trees in North...

A systematic study of the strong interaction with P-barANDA

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

Messchendorp, J. G.

2011-10-21

The theory of Quantum Chromo Dynamics (QCD) reproduces the strong interaction at distances much shorter than the size of the nucleon. At larger distance scales, the generation of hadron masses and confinement cannot yet be derived from first principles on basis of QCD. The PANDA experiment at FAIR will address the origin of these phenomena in controlled environments. Beams of antiprotons together with a multi-purpose and compact detection system will provide unique tools to perform studies of the strong interaction. This will be achieved via precision spectroscopy of charmonium and open-charm states, an extensive search for exotic objects such asmore » glueballs and hybrids, in-medium and hypernuclei spectroscopy, and more. An overview is given of the physics program of the P-barANDA collaboration.« less

Ecosystem and Community Responses to Rainfall Manipulations in Shrublands Depends on Dominant Vegetation Cover

NASA Astrophysics Data System (ADS)

Esch, E. H.; Lipson, D.; Kim, J. B.; Cleland, E. E.

2014-12-01

Southern California is predicted to face decreasing precipitation with increased interannual variability in the coming century. Native shrublands in this area are increasingly invaded by exotic annual grasses, though invasion dynamics can vary by rainfall scenario, with wet years generally associated with high invasion pressure. Interplay between rainfall and invasion scenarios can influence carbon stocks and community composition. Here we asked how invasion alters ecosystem and community responses in drought versus high rainfall scenarios, as quantified by community identity, biomass production, and the normalized difference vegetation index (NDVI). To do this, we performed a rainfall manipulation experiment with paired plots dominated either by native shrubs or exotic herbaceous species, subjected to treatments of 50%, 100%, or 150% of ambient rainfall. The study site was located in a coastal sage scrub ecosystem, with patches dominated by native shrubs and exotic grasses located in San Diego County, USA. During two growing seasons, we found that native, herbaceous biomass production was significantly affected by rainfall treatment (p<0.05 for both years), though was not affected by dominant community composition. Photosynthetic biomass production of shrub species also varied by treatment (p=0.035). Exotic biomass production showed a significant interaction between dominant community composition and rainfall treatment, and both individual effects (p<0.001 for all). NDVI showed similar results, but also indicated the importance of rainfall timing on overall biomass production between years. Community composition data showed certain species, of both native and exotic identities, segregating by treatment. These results indicate that exotic species are more sensitive to rainfall, and that increased rainfall may promote greater carbon storage in annual dominated communities when compared to shrub dominated communities in high rainfall years, but with drought, this trend is reversed.

Great Basin insect outbreaks

Treesearch

Barbara Bentz; Diane Alston; Ted Evans

2008-01-01

Outbreaks of native and exotic insects are important drivers of ecosystem dynamics in the Great Basin. The following provides an overview of range, forest, ornamental, and agricultural insect outbreaks occurring in the Great Basin and the associated management issues and research needs.

Grassland Degradation Alters Soil Carbon Turnover through Depth

NASA Astrophysics Data System (ADS)

Creamer, C.; Prober, S. M.; Chappell, A.; Farrell, M.; Baldock, J.

2015-12-01

Ecosystem degradation is widespread and changes in aboveground plant communities alter belowground soil processes. In Australia, grassy eucalyptus woodlands dominated by kangaroo grasses (Themeda trianda) were widely cleared during European settlement for agriculture, with only fragments remaining of this now threatened ecosystem. As remnant grassland fragments are used for livestock grazing, Themeda transitions through states of degradation, starting with red grasses (Bothriochloa spp) and then proceeding to less productive, increasingly degraded states dominated by either annual exotic weeds or native wallaby grasses (Rytidosperma spp) and spear grasses (Austrastipa spp). The aim of our experiment was to determine how soil organic matter dynamics (including erosion, root biomass, C storage and turnover) have been altered by the transition from deeply-rooted Themeda grass systems to more shallowly-rooted annual exotic weeds and wallaby/spear grass states. We sampled soils in five depth-based increments (0-5, 5-15, 15-30, 30-60, 60-100 cm) across this ecosystem transition at five sites across New South Wales, Australia. Caseium-137 analysis indicated erosion rates were similar among all ecosystems and were consistent with levels for grasslands in the region. Compared to the remnant Themeda grass systems, the degraded states had lower root biomass, lower carbon stocks and C:N ratios in the coarse fraction (> 50 μm), lower fungal : bacterial ratios, higher available phosphate, higher alkyl : O-alkyl C ratios, and faster mineralization of synthetic root-exudate carbon. All these metrics indicate the surprising finding of more microbially processed OM and faster turnover of newly added C in the degraded sites. Compared to one another, the two degraded sites differed in both C and N turnover, with the exotic weeds having higher dissolved organic N, inorganic N, and coarse fraction N, higher fine fraction C stocks, and greater microbial biomass. These differences likely arise from the greater aboveground productivity of exotic weeds relative to the wallaby and spear grasses. Although microbial C turnover through depth is altered with grassland degradation in both states, the trajectory of the soil organic matter dynamics with degradation is also impacted by plant community dynamics.

Neutron-rich nuclei produced at zero degrees in damped collisions induced by a beam of 18O on a 238U target

NASA Astrophysics Data System (ADS)

Stefan, I.; Fornal, B.; Leoni, S.; Azaiez, F.; Portail, C.; Thomas, J. C.; Karpov, A. V.; Ackermann, D.; Bednarczyk, P.; Blumenfeld, Y.; Calinescu, S.; Chbihi, A.; Ciemala, M.; Cieplicka-Oryńczak, N.; Crespi, F. C. L.; Franchoo, S.; Hammache, F.; Iskra, Ł. W.; Jacquot, B.; Janssens, R. V. F.; Kamalou, O.; Lauritsen, T.; Lewitowicz, M.; Olivier, L.; Lukyanov, S. M.; Maccormick, M.; Maj, A.; Marini, P.; Matea, I.; Naumenko, M. A.; de Oliveira Santos, F.; Petrone, C.; Penionzhkevich, Yu. E.; Rotaru, F.; Savajols, H.; Sorlin, O.; Stanoiu, M.; Szpak, B.; Tarasov, O. B.; Verney, D.

2018-04-01

Cross sections and corresponding momentum distributions have been measured for the first time at zero degrees for the exotic nuclei obtained from a beam of 18O at 8.5 MeV/A impinging on a 1 mg/cm2238U target. Sizable cross sections were found for the production of exotic species arising from the neutron transfer and proton removal from the projectile. Comparisons of experimental results with calculations based on deep-inelastic reaction models, taking into account the particle evaporation process, indicate that zero degree is a scattering angle at which the differential reaction cross section for production of exotic nuclei is at its maximum. This result is important in view of the new generation of zero degrees spectrometers under construction, such as the S3 separator at GANIL, for example.

Influence of acid deposition on regeneration dynamics along a disturbance intensity gradient

Treesearch

Sarah E. Stehn; Christopher R. Webster; Michael A. Jenkins; Shibu Jose

2010-01-01

Now considered one of the most threatened vegetation communities in North America, spruce-fir forests of the southern Appalachians have been devastated by the combined impacts of the exotic balsam woolly adelgid (Adelges piceae, BWA) and chronic acid deposition.

Pentaquark Searches at Jlab

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

Rossi, Patrizia

2007-01-01

Since LEPS collaboration reported the first evidence for a S=+1 baryon resonance in early 2003 with a mass of 1.54 GeV, dubbed Θ+, more than ten experiments have confirmed this exotic state, among these two carried out at Jefferson Laboratory. At the same time, there are a number of experiments, mostly at high energies, that report null results. To try to clarify this situation, during the past year, The CLAS Collaboration at Jefferson Laboratory has undertaken a second generation high-statistics experimental program to search for exotics baryons. Here the preliminary results from these experiments are reported.

Technology survey of electrical power generation and distribution for MIUS application

NASA Technical Reports Server (NTRS)

Gill, W. L.; Redding, T. E.

1975-01-01

Candidate electrical generation power systems for the modular integrated utility systems (MIUS) program are described. Literature surveys were conducted to cover both conventional and exotic generators. Heat-recovery equipment associated with conventional power systems and supporting equipment are also discussed. Typical ranges of operating conditions and generating efficiencies are described. Power distribution is discussed briefly. Those systems that appear to be applicable to MIUS have been indicated, and the criteria for equipment selection are discussed.

Predicting the potential distribution of invasive exotic species using GIS and information-theoretic approaches: A case of ragweed (Ambrosia artemisiifolia L.) distribution in China

USGS Publications Warehouse

Hao, Chen; LiJun, Chen; Albright, Thomas P.

2007-01-01

Invasive exotic species pose a growing threat to the economy, public health, and ecological integrity of nations worldwide. Explaining and predicting the spatial distribution of invasive exotic species is of great importance to prevention and early warning efforts. We are investigating the potential distribution of invasive exotic species, the environmental factors that influence these distributions, and the ability to predict them using statistical and information-theoretic approaches. For some species, detailed presence/absence occurrence data are available, allowing the use of a variety of standard statistical techniques. However, for most species, absence data are not available. Presented with the challenge of developing a model based on presence-only information, we developed an improved logistic regression approach using Information Theory and Frequency Statistics to produce a relative suitability map. This paper generated a variety of distributions of ragweed (Ambrosia artemisiifolia L.) from logistic regression models applied to herbarium specimen location data and a suite of GIS layers including climatic, topographic, and land cover information. Our logistic regression model was based on Akaike's Information Criterion (AIC) from a suite of ecologically reasonable predictor variables. Based on the results we provided a new Frequency Statistical method to compartmentalize habitat-suitability in the native range. Finally, we used the model and the compartmentalized criterion developed in native ranges to "project" a potential distribution onto the exotic ranges to build habitat-suitability maps. ?? Science in China Press 2007.

Exotic grasses and nitrate enrichment alter soil carbon cycling along an urban-rural tropical forest gradient.

PubMed

Cusack, Daniela F; Lee, Joseph K; McCleery, Taylor L; LeCroy, Chase S

2015-12-01

Urban areas are expanding rapidly in tropical regions, with potential to alter ecosystem dynamics. In particular, exotic grasses and atmospheric nitrogen (N) deposition simultaneously affect tropical urbanized landscapes, with unknown effects on properties like soil carbon (C) storage. We hypothesized that (H1) soil nitrate (NO3 (-) ) is elevated nearer to the urban core, reflecting N deposition gradients. (H2) Exotic grasslands have elevated soil NO3 (-) and decreased soil C relative to secondary forests, with higher N promoting decomposer activity. (H3) Exotic grasslands have greater seasonality in soil NO3 (-) vs. secondary forests, due to higher sensitivity of grassland soil moisture to rainfall. We predicted that NO3 (-) would be positively related to dissolved organic C (DOC) production via changes in decomposer activity. We measured six paired grassland/secondary forest sites along a tropical urban-to-rural gradient during the three dominant seasons (hurricane, dry, and early wet). We found that (1) soil NO3 (-) was generally elevated nearer to the urban core, with particularly clear spatial trends for grasslands. (2) Exotic grasslands had lower soil C than secondary forests, which was related to elevated decomposer enzyme activities and soil respiration. Unexpectedly, soil NO3 (-) was negatively related to enzyme activities, and was lower in grasslands than forests. (3) Grasslands had greater soil NO3 (-) seasonality vs. forests, but this was not strongly linked to shifts in soil moisture or DOC. Our results suggest that exotic grasses in tropical regions are likely to drastically reduce soil C storage, but that N deposition may have an opposite effect via suppression of enzyme activities. However, soil NO3 (-) accumulation here was higher in urban forests than grasslands, potentially related to of aboveground N interception. Net urban effects on C storage across tropical landscapes will likely vary depending on the mosaic of grass cover, rates of N deposition, and responses by local decomposer communities. © 2015 John Wiley & Sons Ltd.

Stand Dynamics of Coast Redwood/Tanoak Forests Following Tanoak Decline

Treesearch

Kristen M. Waring; Kevin L. O' Hara

2007-01-01

Current threats to North American forests increasingly include exotic tree pathogens that cause extensive mortality. In California, tanoak (Lithocarpus densiflorus) mortality has increased rapidly since 1995, due to Phytophthora ramorum, believed to be an introduced pathogen. Tanoak frequently grows as a major component of redwood...

Urban Pest Management of Ants in California

USDA-ARS?s Scientific Manuscript database

Keeping pace with the dynamic and evolving landscape of invasive ants in California presents a formidable challenge to the pest management industry. Pest management professionals (PMPs) are on the frontlines when it comes to battling these exotic ant pests, and are often the first ones to intercept ...

Exploration of a rare population of Chinese chestnut in North America: stand dynamics, health and genetic relationships

PubMed Central

Miller, Amy C.; Woeste, Keith E.; Anagnostakis, Sandra L.; Jacobs, Douglass F.

2014-01-01

With the transport of plants around the globe, exotic species can readily spread disease to their native relatives; however, they can also provide genetic resistance to those relatives through hybrid breeding programmes. American chestnut (Castanea dentata) was an abundant tree species in North America until its decimation by introduced chestnut blight. To restore chestnut in North America, efforts are ongoing to test putative blight-resistant hybrids of Castanea dentata and Chinese chestnut (Castanea mollissima), but little is known about the ecology of C. mollissima. In a forest in northeastern USA in which C. mollissima has become established, we explored questions of stand dynamics, health and genetic relationships of C. mollissima offspring to an adjacent parent orchard. We found that C. mollissima was adapted and randomly distributed among native species in this relatively young forest. The genetics of the C. mollissima population compared with its parents indicated little effect of selection pressure as each of the parent trees contributed at least one offspring. The ease with which this exotic species proliferated calls to question why C. mollissima is rare elsewhere in forests of North America. It is likely that a time window of low animal predation allowed seedlings to establish, and the shallow soil at this site limited the maximum forest canopy height, permitting the characteristically short-statured C. mollissima to avoid suppression. Our results indicate that because C. mollissima exhibited pioneer species characteristics, hybrids between C. mollissima and C. dentata have the potential to be successful pioneer species of future forests in North America, and we challenge the paradigm that exotic tree species are wholly detrimental to native biodiversity. We contend that exotic tree species should be assessed not only by their level of threat to native species, but also by their potential positive impacts on ecosystems via hybrid breeding programmes. PMID:25336337

Exploration of a rare population of Chinese chestnut in North America: stand dynamics, health and genetic relationships.

PubMed

Miller, Amy C; Woeste, Keith E; Anagnostakis, Sandra L; Jacobs, Douglass F

2014-10-20

With the transport of plants around the globe, exotic species can readily spread disease to their native relatives; however, they can also provide genetic resistance to those relatives through hybrid breeding programmes. American chestnut (Castanea dentata) was an abundant tree species in North America until its decimation by introduced chestnut blight. To restore chestnut in North America, efforts are ongoing to test putative blight-resistant hybrids of Castanea dentata and Chinese chestnut (Castanea mollissima), but little is known about the ecology of C. mollissima. In a forest in northeastern USA in which C. mollissima has become established, we explored questions of stand dynamics, health and genetic relationships of C. mollissima offspring to an adjacent parent orchard. We found that C. mollissima was adapted and randomly distributed among native species in this relatively young forest. The genetics of the C. mollissima population compared with its parents indicated little effect of selection pressure as each of the parent trees contributed at least one offspring. The ease with which this exotic species proliferated calls to question why C. mollissima is rare elsewhere in forests of North America. It is likely that a time window of low animal predation allowed seedlings to establish, and the shallow soil at this site limited the maximum forest canopy height, permitting the characteristically short-statured C. mollissima to avoid suppression. Our results indicate that because C. mollissima exhibited pioneer species characteristics, hybrids between C. mollissima and C. dentata have the potential to be successful pioneer species of future forests in North America, and we challenge the paradigm that exotic tree species are wholly detrimental to native biodiversity. We contend that exotic tree species should be assessed not only by their level of threat to native species, but also by their potential positive impacts on ecosystems via hybrid breeding programmes. Published by Oxford University Press on behalf of the Annals of Botany Company.

Effects of seasonality on drosophilids (Insecta, Diptera) in the northern part of the Atlantic Forest, Brazil.

PubMed

Coutinho-Silva, R D; Montes, M A; Oliveira, G F; de Carvalho-Neto, F G; Rohde, C; Garcia, A C L

2017-10-01

Seasonality is an important aspect associated with population dynamic and structure of tropical insect assemblages. This study evaluated the effects of seasonality on abundance, richness, diversity and composition of an insect group, drosophilids, including species native to the Neotropical region and exotic ones. Three preserved fragments of the northern Atlantic Forest were surveyed, where temperatures are above 20 °C throughout the year and rainfall regimes define two seasons (dry and rainy). As opposed to other studies about arthropods in tropical regions, we observed that abundance of drosophilids was significantly higher in the dry season, possibly due to biological aspects and the colonization strategy adopted by the exotic species in these environments. Contrarily to abundance, we did not observe a seasonal pattern for richness. As for other parts of the Atlantic Forest, the most representative Neotropical species (Drosophila willistoni, D. sturtevanti, D. paulistorum and D. prosaltans) were significantly more abundant in the rainy season. Among the most abundant exotic species, D. malerkotliana, Zaprionus indianus and Scaptodrosophila latifasciaeformis were more importantly represented the dry season, while D. simulans was more abundant in the rainy period. The seasonality patterns exhibited by the most abundant species were compared to findings published in other studies. Our results indicate that exotic species were significantly more abundant in the dry season, while native ones exhibited an opposite pattern.

Apparent competition with an exotic plant reduces native plant establishment.

PubMed

Orrock, John L; Witter, Martha S; Reichman, O J

2008-04-01

Biological invasions can change ecosystem function, have tremendous economic costs, and impact human health; understanding the forces that cause and maintain biological invasions is thus of immediate importance. A mechanism by which exotic plants might displace native plants is by increasing the pressure of native consumers on native plants, a form of indirect interaction termed "apparent competition." Using experimental exclosures, seed addition, and monitoring of small mammals in a California grassland, we examined whether exotic Brassica nigra increases the pressure of native consumers on a native bunchgrass, Nassella pulchra. Experimental plots were weeded to focus entirely on indirect effects via consumers. We demonstrate that B. nigra alters the activity of native small-mammal consumers, creating a gradient of consumption that dramatically reduces N. pulchra establishment. Previous work has shown that N. pulchra is a strong competitor, but that it is heavily seed limited. By demonstrating that consumer pressure is sufficient to curtail establishment, our work provides a mechanism for this seed limitation and suggests that, despite being a good competitor, N. pulchra cannot reestablish close to B. nigra within its old habitats because exotic-mediated consumption preempts direct competitive exclusion. Moreover, we find that apparent competition has a spatial extent, suggesting that consumers may dictate the rate of invasion and the area available for restoration, and that nonspatial studies of apparent competition may miss important dynamics.

Dynamics of House Sparrows (Passer domesticus) in Newcastle disease virus transmission within the avifaunal-poultry interface: an epidemiological modeling approach

USDA-ARS?s Scientific Manuscript database

As emerging and persistent pathogens increase in prevalence, the agriculture-wildlife interface has been identified as a field requiring further research. Acceleration of wildlife urbanization, exotic species introductions, and habitat encroachment are disrupting barriers that once separated microb...

Expression profiles and clinical value of plasma exosomal Tim-3 and Galectin-9 in non-small cell lung cancer.

PubMed

Gao, Jianwei; Qiu, Xiangyu; Li, Xinying; Fan, Hang; Zhang, Fang; Lv, Tangfeng; Song, Yong

2018-04-06

Exosomes are membrane-bound, virus-sized vesicles present in circulating blood. Tumor cells are avid producers of exosomes, which are thought to mimic molecular features of parent tumor cells. T-cell immunoglobulin- and mucin-domain-containing molecule 3 (Tim-3) is a the next-generation immune checkpoint that can be activated by its ligand Galectin-9 to negatively regulate the anti-tumor immune response. However, the characteristics of plasma exosomal Tim-3 and Galectin-9 (Exo-T/G) in cancer remained unknown. This study was conducted to investigate the expression patterns and clinical value of plasma exosomal total protein (Exo-pro) and Exo-T/G in non-small cell lung cancer (NSCLC). Plasma was collected from 103 NSCLC patients including 60 early stages and 43 advanced stages disease samples as well as 56 healthy subjects. Exosomes were isolated from plasma by commercial exosome precipitation solution and identified by western blotting of CD63 and transmission electron microscopy. Exo-pro concentration was measured by the BCA assay. Enzyme-linked immunosorbent assay was used to quantify Exo-T/G. Additionally, 34 NSCLC samples were applied to directly detect plasma TIM-3 (Plas-T) and Galectin-9 (Plas-G). Our results showed that Exo-pro, Exo-T, and Exo-G were significantly increased in NSCLC plasma compared to that in the healthy samples. High levels of Exo-T and Exo-G were all positively correlated with several malignant parameters, including larger tumor size, advanced stages, and more distant metastasis. High levels of Exo-pro and Exo-T were also correlated with more lymph node metastasis. Additionally, plasma from lung squamous cell carcinoma showed higher Exo-T and Exo-G compared with that from lung adenocarcinoma. ALK-positive patients showed to have decreased Exo-T and Exo-G levels. Pearson's correlation analysis revealed a significant correlation between Exo-pro and Exo-T/G, Exo-T and Exo-G, Exo-T and Plas-T, Exo-G and Plas-G, and Plas-T and Plas-G. Together, our data revealed that Exo-pro, especially Exo-T and Exo-G could be potential biomarkers for NSCLC. Further studies focusing on pure tumor-derived exosomes isolated from plasma were needed. Copyright © 2018 Elsevier Inc. All rights reserved.

Transparency of near-critical density plasmas under extreme laser intensities

NASA Astrophysics Data System (ADS)

Ji, Liangliang; Shen, Baifei; Zhang, Xiaomei

2018-05-01

We investigated transparency of near-critical plasma targets for highly intense incident lasers and discovered that beyond relativistic transparency, there exists an anomalous opacity regime, where the plasma target tend to be opaque at extreme light intensities. The unexpected phenomenon is found to originate from the trapping of ions under exotic conditions. We found out the propagation velocity and the amplitude of the laser-driven charge separation field in a large parameter range and derived the trapping probability of ions. The model successfully interpolates the emergence of anomalous opacity in simulations. The trend is more significant when radiation reaction comes into effect, leaving a transparency window in the intensity domain. Transparency of a plasma target defines the electron dynamics and thereby the emission mechanisms of gamma-photons in the ultra-relativistic regime. Our findings are not only of fundamental interest but also imply the proper mechanisms for generating desired electron/gamma sources.

Extinction phase transitions in a model of ecological and evolutionary dynamics

NASA Astrophysics Data System (ADS)

Barghathi, Hatem; Tackkett, Skye; Vojta, Thomas

2017-07-01

We study the non-equilibrium phase transition between survival and extinction of spatially extended biological populations using an agent-based model. We especially focus on the effects of global temporal fluctuations of the environmental conditions, i.e., temporal disorder. Using large-scale Monte-Carlo simulations of up to 3 × 107 organisms and 105 generations, we find the extinction transition in time-independent environments to be in the well-known directed percolation universality class. In contrast, temporal disorder leads to a highly unusual extinction transition characterized by logarithmically slow population decay and enormous fluctuations even for large populations. The simulations provide strong evidence for this transition to be of exotic infinite-noise type, as recently predicted by a renormalization group theory. The transition is accompanied by temporal Griffiths phases featuring a power-law dependence of the life time on the population size.

Materials science: Clockwork at the atomic scale

NASA Astrophysics Data System (ADS)

Ležaić, Marjana

2016-05-01

Design rules for exotic materials known as polar metals have been put into practice in thin films. The findings will motivate studies of how a phenomenon called screening can be manipulated to generate new phases in metals. See Letter p.68

Sudden Oak Death in redwood forests: vegetation dynamics in the wake of tanoak decline

Treesearch

Benjamin Ramage; Kevin O’Hara

2010-01-01

Numerous lines of inquiry have concluded that tanoak (Lithocarpus densiflorus) will continue to experience drastic population declines and may even disappear entirely from redwood (Sequoia sempervirens) forests as a result of the exotic disease sudden oak death (SOD) (Maloney and others 2005, McPherson and others 2005,...

Extreme gravity tests with gravitational waves from compact binary coalescences: (II) ringdown

NASA Astrophysics Data System (ADS)

Berti, Emanuele; Yagi, Kent; Yang, Huan; Yunes, Nicolás

2018-05-01

The LIGO/Virgo detections of binary black hole mergers marked a watershed moment in astronomy, ushering in the era of precision tests of Kerr dynamics. We review theoretical and experimental challenges that must be overcome to carry out black hole spectroscopy with present and future gravitational wave detectors. Among other topics, we discuss quasinormal mode excitation in binary mergers, astrophysical event rates, tests of black hole dynamics in modified theories of gravity, parameterized "post-Kerr" ringdown tests, exotic compact objects, and proposed data analysis methods to improve spectroscopic tests of Kerr dynamics by stacking multiple events.

A model describing the effect of sex-reversed YY fish in an established wild population: The use of a Trojan Y chromosome to cause extinction of an introduced exotic species.

PubMed

Gutierrez, Juan B; Teem, John L

2006-07-21

A novel means of inducing extinction of an exotic fish population is proposed using a genetic approach to shift the ratio of male to females within a population. In the proposed strategy, sex-reversed fish containing two Y chromosomes are introduced into a normal fish population. These YY fish result in the production of a disproportionate number of male fish in subsequent generations. Mathematical modeling of the system following introduction of YY fish at a constant rate reveals that female fish decline in numbers over time, leading to eventual extinction of the population.

Co-occurrence dynamics of endangered Lower Keys marsh rabbits and free-ranging domestic cats: Prey responses to an exotic predator removal program.

PubMed

Cove, Michael V; Gardner, Beth; Simons, Theodore R; O'Connell, Allan F

2018-04-01

The Lower Keys marsh rabbit ( Sylvilagus palustris hefneri ) is one of many endangered endemic species of the Florida Keys. The main threats are habitat loss and fragmentation from sea-level rise, development, and habitat succession. Exotic predators such as free-ranging domestic cats ( Felis catus ) pose an additional threat to these endangered small mammals. Management strategies have focused on habitat restoration and exotic predator control. However, the effectiveness of predator removal and the effects of anthropogenic habitat modifications and restoration have not been evaluated. Between 2013 and 2015, we used camera traps to survey marsh rabbits and free-ranging cats at 84 sites in the National Key Deer Refuge, Big Pine Key, Florida, USA. We used dynamic occupancy models to determine factors associated with marsh rabbit occurrence, colonization, extinction, and the co-occurrence of marsh rabbits and cats during a period of predator removal. Rabbit occurrence was positively related to freshwater habitat and patch size, but was negatively related to the number of individual cats detected at each site. Furthermore, marsh rabbit colonization was negatively associated with relative increases in the number of individual cats at each site between survey years. Cat occurrence was negatively associated with increasing distance from human developments. The probability of cat site extinction was positively related to a 2-year trapping effort, indicating that predator removal reduced the cat population. Dynamic co-occurrence models suggested that cats and marsh rabbits co-occur less frequently than expected under random conditions, whereas co-detections were site and survey-specific. Rabbit site extinction and colonization were not strongly conditional on cat presence, but corresponded with a negative association. Our results suggest that while rabbits can colonize and persist at sites where cats occur, it is the number of individual cats at a site that more strongly influences rabbit occupancy and colonization. These findings indicate that continued predator management would likely benefit endangered small mammals as they recolonize restored habitats.

Study of Nonlinear Propagation of Ultrashort Laser Pulses and Its Application to Harmonic Generation

NASA Astrophysics Data System (ADS)

Weerawarne, Darshana L.

Laser filamentation, which is one of the exotic nonlinear optical phenomena, is self-guidance of high-power laser beams due to the dynamic balance between the optical Kerr effect (self-focusing) and other nonlinear effects such as plasma defocusing. It has many applications including supercontinuum generation (SCG), high-order harmonic generation (HHG), lightning guiding, stand-off sensing, and rain making. The main focus of this work is on studying odd-order harmonic generation (HG) (i.e., 3o, 5o, 7o, etc., where o is the angular frequency) in centrosymmetric media while a high-power, ultrashort harmonic-driving pulse undergoes nonlinear propagation such as laser filamentation. The investigation of highly-controversial nonlinear indices of refraction by measuring low-order HG in air is carried out. Furthermore, time-resolved (i.e., pump-probe) experiments and significant harmonic enhancements are presented and a novel HG mechanism based on higher-order nonlinearities is proposed to explain the experimental results. C/C++ numerical simulations are used to solve the nonlinear Schrodinger equation (NLSE) which supports the experimental findings. Another project which I have performed is selective sintering using lasers. Short-pulse lasers provide a fascinating tool for material processing, especially when the conventional oven-based techniques fail to process flexible materials for smart energy/electronics applications. I present experimental and theoretical studies on laser processing of nanoparticle-coated flexible materials, aiming to fabricate flexible electronic devices.

Search for new T' particles in final states with large jet multiplicities and missing transverse energy in pp collisions at √s=1.96 TeV

DOE PAGES

Aaltonen, T.

2011-11-11

We present a search for a new particle T decaying to a top quark via T = t + X, where X goes undetected. We use a data sample corresponding to 5.7 fb -1 of integrated luminosity of pp collisions with √s = 1.96 TeV, collected at Fermilab Tevatron by the CDF II detector. Our search for pair production of T' is focused on the hadronic decay channel, pp = TT= tt+XX=bqqbqq + XX. We interpret our results in terms of a model where T is an exotic fourth generation quark and X is a dark matter particle. The datamore » are consistent with standard model expectations. We set a limit on the generic production of TT = tt =+ XX, excluding the fourth generation exotic quarks T at 95% confidence level up to m T = 400 GeV/c 2 for m X ≤ 70 GeV/c 2.« less

Dynamics of interacting fermions under spin-orbit coupling in an optical lattice clock

NASA Astrophysics Data System (ADS)

Bromley, S. L.; Kolkowitz, S.; Bothwell, T.; Kedar, D.; Safavi-Naini, A.; Wall, M. L.; Salomon, C.; Rey, A. M.; Ye, J.

2018-04-01

Quantum statistics and symmetrization dictate that identical fermions do not interact via s-wave collisions. However, in the presence of spin-orbit coupling (SOC), fermions prepared in identical internal states with distinct momenta become distinguishable. The resulting strongly interacting system can exhibit exotic topological and pairing behaviours, many of which are yet to be observed in condensed matter systems. Ultracold atomic gases offer a promising pathway for simulating these rich phenomena, but until recently have been hindered by heating and losses. Here we enter a new regime of many-body interacting SOC in a fermionic optical lattice clock (OLC), where the long-lived electronic clock states mitigate unwanted dissipation. Using clock spectroscopy, we observe the precession of the collective magnetization and the emergence of spin-locking effects arising from an interplay between p-wave and SOC-induced exchange interactions. The many-body dynamics are well captured by a collective XXZ spin model, which describes a broad class of condensed matter systems ranging from superconductors to quantum magnets. Furthermore, our work will aid in the design of next-generation OLCs by offering a route for avoiding the observed large density shifts caused by SOC-induced exchange interactions.

Structures in general relativity

NASA Astrophysics Data System (ADS)

Tieu, Steven

Structures within general relativity are examined. The differences between man-made structures and those predicted by the Einstein differential equations are very subtle. Exotic structures such as the Godel Universe and the Gott cosmic string are examined with emphasis on closed time-like curves. Newtonian models are seen to also have an exotic aspect in that a vast halo consisting of unknown matter dominates the galaxy. We introduce a model for galaxies based on a general relativity framework with the goal of excluding such artifacts from the system while describing the flat-rotation curves. Structures within this model were speculated to be exotic but after close scrutiny, their nature is shown to be benign. Numerical approaches are applied to model four galaxies: The Milky Way, NGC 3031, NGC 3198 and NGC 7331. Density and mass are deduced from these models and compared to the Newtonian models. Within the visible/HI region, there is 30% reduction in total mass. Extending the model to 10 times beyond the HI region using various fall-off scenerios, it is shown that there is only modest increase of the accumulated mass. In comparison to the Newtonian approach to galactic dynamics, the massive halos are not required to account for the flat velocity profiles.

Infestation dynamics of the Asian longhorned beetle in the United States

Treesearch

Alan Sawyer

2007-01-01

The Asian longhorned beetle (ALB), Anoplophora glabripennis (Coleoptera: Cerambycidae), is an exotic pest of Asian origin, first discovered in North America (Brooklyn, NY) in 1996. That infestation has now spread to Queens, Manhattan and Long Island, NY and Jersey City, NJ. Based on DNA profiles (Carter et al. 2005) and other evidence, independent...

Impacts of Hemlock Loss on Nitrogen Retention Vary with Soil Nitrogen Availability in the Southern Appalachian Mountains

Treesearch

Corinne E. Block; Jennifer D. Knoepp; Katherine J. Elliott; Jennifer M. Fraterrigo

2012-01-01

The impacts of exotic insects and pathogens on forest ecosystems are increasingly recognized, yet the factors influencing the magnitude of effects remain poorly understood. Eastern hemlock (Tsuga canadensis) exerts strong control on nitrogen (N) dynamics, and its loss due to infestation by the hemlock woolly adelgid (Adelges tsugae...

Exploration of a rare population of Chinese chestnut in North America: stand dynamics, health and genetic relationships

Treesearch

Amy C. Miller; Keith E. Woeste; Sandra L. Anagnostakis; Doutlass F. Jacobs

2014-01-01

With the transport of plants around the globe, exotic species can readily spread disease to their native relatives; however, they can also provide genetic resistance to those relatives through hybrid breeding programmes. American chestnut (Castanea dentata) was an abundant tree species in North America until its decimation by introduced chestnut...

Interactions of landscape disturbances and climate change dictate ecological pattern and process: spatial modeling of wildfire, insect, and disease dynamics under future climates

Treesearch

Rachel A. Loehman; Robert E. Keane; Lisa M. Holsinger; Zhiwei Wu

2017-01-01

Context: Interactions among disturbances, climate, and vegetation influence landscape patterns and ecosystem processes. Climate changes, exotic invasions, beetle outbreaks, altered fire regimes, and human activities may interact to produce landscapes that appear and function beyond historical analogs. Objectives We used the mechanistic...

Phenomenological Consequences of the Constrained Exceptional Supersymmetric Standard Model

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

Athron, Peter; King, S. F.; Miller, D. J.

2010-02-10

The Exceptional Supersymmetric Standard Model (E{sub 6}SSM) provides a low energy alternative to the MSSM, with an extra gauged U(1){sub N} symmetry, solving the mu-problem of the MSSM. Inspired by the possible embedding into an E{sub 6} GUT, the matter content fills three generations of E{sub 6} multiplets, thus predicting exciting exotic matter such as diquarks or leptoquarks. We present predictions from a constrained version of the model (cE{sub 6}SSM), with a universal scalar mass m{sub 0}, trilinear mass A and gaugino mass M{sub 1/2}. We reveal a large volume of the cE{sub 6}SSM parameter space where the correct breakdownmore » of the gauge symmetry is achieved and all experimental constraints satisfied. We predict a hierarchical particle spectrum with heavy scalars and light gauginos, while the new exotic matter can be light or heavy depending on parameters. We present representative cE{sub 6}SSM scenarios, demonstrating that there could be light exotic particles, like leptoquarks and a U(1){sub N} Z' boson, with spectacular signals at the LHC.« less

Oxygen-Free Biochemistry: The Putative CHN Foundation for Exotic Life in a Hydrocarbon World?

NASA Astrophysics Data System (ADS)

Lv, Kong-Peng; Norman, Lucy; Li, Yi-Liang

2017-11-01

Since Earth's biochemistry is carbon-based and water-borne, the main strategies for searching for life elsewhere are "follow the carbon" and "follow the water." Recently, however, there is a growing focus on the prospect that putative exotic life on other planets could rely on unearthly biochemistries. Here, we hypothesize a novel oxygen-free organic chemistry for supporting potential exotic biosystems, which is named CHN biochemistry. This oxygen-free CHN biochemistry starts from simple oxygen-free species (including hydrocarbons, hydrogen cyanide, and nitriles) and produces a range of functional macromolecules that may function in similar ways to terran macromolecules, such as sugars (cyanosugars), acids (cyanoacids), amino acids (amino cyanoacids), and nucleobases (cyanonucleobases). These CHN macromolecules could further interact with each other to generate higher "cyanoester" and "cyanoprotein" systems. In addition, theoretical calculations indicate that the energy changes of some reactions are consistent with their counterparts in Earth's biochemistry. The CHN biochemistry-based life would be applicable in habitats with a low bioavailability of oxygen, such as the alkane lakes of Titan and non-aquatic liquids on extrasolar bodies.

Exotic plant species associations with horse trails, old roads, and intact native communities in the Missouri Ozarks

USGS Publications Warehouse

Stroh, E.D.; Struckhoff, M.A.

2009-01-01

We compared the extent to which exotic species are associated with horse trails, old roads, and intact communities within three native vegetation types in Ozark National Scenic Riverways, Missouri. We used a general linear model procedure and a Bonferroni multiple comparison test to compare exotic species richness, exotic to native species ratios, and exotic species percent cover across three usage types (horse trails, old roads, and intact communities) and three community types (river bottoms, upland waterways, and glades). We found that both exotic species richness and the ratio of exotic species to native species were greater in plots located along horse trails than in plots located either in intact native communities or along old roads. Native community types did not differ in the number of exotic species present, but river bottoms had a significantly higher exotic to native species ratio than glades. Continued introduction of exotic plant propagules may explain why horse trails contain more exotic species than other areas in a highly disturbed landscape.

Sagebrush ecosystems: current status and trends.

USGS Publications Warehouse

Beever, E.A.; Connelly, J.W.; Knick, S.T.; Schroeder, M.A.; Stiver, S. J.

2004-01-01

The sagebrush (Artemisia spp.) biome has changed since settlement by Europeans. The current distribution, composition and dynamics, and disturbance regimes of sagebrush ecosystems have been altered by interactions among disturbance, land use, and invasion of exotic plants. In this chapter, we present the dominant factors that have influenced habitats across the sagebrush biome. Using a large-scale analysis, we identified regional changes and patterns in “natural disturbance”, invasive exotic species, and influences of land use in sagebrush systems. Number of fires and total area burned has increased since 1980 across much of the sagebrush biome. Juniper (Juniperus spp.) and pinyon (Pinus spp.) woodlands have expanded into sagebrush habitats at higher elevations. Cheatgrass (Bromus tectorum), an exotic annual grass, has invaded much of lower elevation, more xeric sagebrush landscapes across the western portion of the biome. Consequently, synergistic feedbacks between habitats and disturbance (natural and human-caused) have altered disturbance regimes, plant community dynamics and contributed to loss of sagebrush habitats and change in plant communities. Habitat conversion to agriculture has occurred in the highly productive regions of the sagebrush biome and influenced up to 56% of the Conservation Assessment area. Similarly, urban areas, and road, railroad, and powerline networks fragment habitats, facilitate predator movements, and provide corridors for spread of exotic species across the entire sagebrush biome. Livestock grazing has altered sagebrush habitats; the effects of overgrazing combined with drought on plant communities in the late 1880s and early 1900s still influences current habitats. Management of livestock grazing has influenced sagebrush ecosystems by habitat treatments to increase forage and reduce sagebrush and other plant species unpalatable to livestock. Fences, roads, and water developments to manage livestock movements have further influenced the landscape and increased access into sagebrush habitats. Energy development also influenced sagebrush landscapes by construction of wells, access roads, and pipelines. Treatments to restore sagebrush are becoming a major emphasis of land management agencies. However, revegetation and rehabilitation treatments are limited by the financial, biological, and technological resources needed to restore sagebrush landscapes that function at the spatial and temporal scales used by sage-grouse (Centrocercus urophasianus)

A strategy for male sterility facilitated recurrent selection in peach

USDA-ARS?s Scientific Manuscript database

Commercial peach is a highly homozygous self-compatible species with limited diversity. The incorporation of exotic germplasm and breeding of new varieties is hindered by the labor required to generate large segregating populations. Hand pollinations are characterized by a high failure rate with onl...

Predicting invasion in grassland ecosystems: Is exotic dominance the real embarrassment of richness?

USGS Publications Warehouse

Seabloom, Eric; Borer, Elizabeth; Buckley, Yvonne; Cleland, Elsa E.; Davies, Kendi; Firn, Jennifer; Harpole, W. Stanley; Hautier, Yann; Lind, Eric M.; MacDougall, Andrew; Orrock, John L.; Prober, Suzanne M.; Adler, Peter; Alberti, Juan; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Blumenthal, Dana; Brown, Cynthia S.; Brudvig, Lars A.; Caldeira, Maria; Chu, Cheng-Jin; Crawley, Michael J.; Daleo, Pedro; Damschen, Ellen Ingman; D'Antonio, Carla M.; DeCrappeo, Nicole M.; Dickman, Chris R.; Du, Guozhen; Fay, Philip A.; Frater, Paul; Gruner, Daniel S.; Hagenah, Nicole; Hector, Andrew; Helm, Aveliina; Hillebrand, Helmut; Hofmockel, Kirsten S.; Humphries, Hope C.; Iribarne, Oscar; Jin, Virginia L.; Kay, Adam; Kirkman, Kevin P.; Klein, Julia A.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Ladwig, Laura M.; ,; John, G.; Leakey, Andrew D.B.; Li, Qi; Li, Wei; McCulley, Rebecca; Melbourne, Brett; ,; Charles, E.; Moore, Joslin L.; Morgan, John; Mortensen, Brent; O'Halloran, Lydia R.; Pärtel, Meelis; Pascual, Jesús; Pyke, David A.; Risch, Anita C.; Salguero-Gómez, Roberto; Sankaran, Mahesh; Schuetz, Martin; Simonsen, Anna; Smith, Melinda; Stevens, Carly; Sullivan, Lauren; Wardle, Glenda M.; Wolkovich, Elizabeth M.; Wragg, Peter D.; Wright, Justin; Yang, Louie

2013-01-01

Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, native community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring species' relative abundance will more rapidly advance our understanding of invasions

Predicting invasion in grassland ecosystems: is exotic dominance the real embarrassment of richness?

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

Seabloom, Eric W.; Borer, Elizabeth T.; Buckley, Yvonne

2013-10-16

Invasions have increased the size of regional species pools, but are typically assumed to reduce native diversity. However, global-scale tests of this assumption have been elusive because of the focus on exotic species richness, rather than relative abundance. This is problematic because low invader richness can indicate invasion resistance by the native community or, alternatively, dominance by a single exotic species. Here, we used a globally replicated study to quantify relationships between exotic richness and abundance in grass-dominated ecosystems in 13 countries on six continents, ranging from salt marshes to alpine tundra. We tested effects of human land use, nativemore » community diversity, herbivore pressure, and nutrient limitation on exotic plant dominance. Despite its widespread use, exotic richness was a poor proxy for exotic dominance at low exotic richness, because sites that contained few exotic species ranged from relatively pristine (low exotic richness and cover) to almost completely exotic-dominated ones (low exotic richness but high exotic cover). Both exotic cover and richness were predicted by native plant diversity (native grass richness) and land use (distance to cultivation). Although climate was important for predicting both exotic cover and richness, climatic factors predicting cover (precipitation variability) differed from those predicting richness (maximum temperature and mean temperature in the wettest quarter). Herbivory and nutrient limitation did not predict exotic richness or cover. Exotic dominance was greatest in areas with low native grass richness at the site- or regional-scale. Although this could reflect native grass displacement, a lack of biotic resistance is a more likely explanation, given that grasses comprise the most aggressive invaders. These findings underscore the need to move beyond richness as a surrogate for the extent of invasion, because this metric confounds monodominance with invasion resistance. Monitoring species’ relative abundance will more rapidly advance our understanding of invasions.« less

Resilience and resistance of sagebrush ecosystems: implications for state and transition models and management treatments

USGS Publications Warehouse

Chambers, Jeanne C.; Miller, Richard F.; Board, David I.; Pyke, David A.; Roundy, Bruce A.; Grace, James B.; Schupp, Eugene W.; Tausch, Robin J.

2014-01-01

In sagebrush ecosystems invasion of annual exotics and expansion of piñon (Pinus monophylla Torr. and Frem.) and juniper (Juniperus occidentalis Hook., J. osteosperma [Torr.] Little) are altering fire regimes and resulting in large-scale ecosystem transformations. Management treatments aim to increase resilience to disturbance and enhance resistance to invasive species by reducing woody fuels and increasing native perennial herbaceous species. We used Sagebrush Steppe Treatment Evaluation Project data to test predictions on effects of fire vs. mechanical treatments on resilience and resistance for three site types exhibiting cheatgrass (Bromus tectorum L.) invasion and/or piñon and juniper expansion: 1) warm and dry Wyoming big sagebrush (WY shrub); 2) warm and moist Wyoming big sagebrush (WY PJ); and 3) cool and moist mountain big sagebrush (Mtn PJ). Warm and dry (mesic/aridic) WY shrub sites had lower resilience to fire (less shrub recruitment and native perennial herbaceous response) than cooler and moister (frigid/xeric) WY PJ and Mtn PJ sites. Warm (mesic) WY Shrub and WY PJ sites had lower resistance to annual exotics than cool (frigid to cool frigid) Mtn PJ sites. In WY shrub, fire and sagebrush mowing had similar effects on shrub cover and, thus, on perennial native herbaceous and exotic cover. In WY PJ and Mtn PJ, effects were greater for fire than cut-and-leave treatments and with high tree cover in general because most woody vegetation was removed increasing resources for other functional groups. In WY shrub, about 20% pretreatment perennial native herb cover was necessary to prevent increases in exotics after treatment. Cooler and moister WY PJ and especially Mtn PJ were more resistant to annual exotics, but perennial native herb cover was still required for site recovery. We use our results to develop state and transition models that illustrate how resilience and resistance influence vegetation dynamics and management options.

JSF/F-35 Pollution Prevention Activities

DTIC Science & Technology

2006-05-01

Liquid Oxygen •Produces Oxygen-Rich Breathing Gas From Engine Bleed Air Using Molecular Sieve Technology •No Exotic Cleaning Solutions •Military No...Explosion from Bullets/Shrapnel •On-Board Inert Gas Generating System (OBIGGS) Replaced Halon 1301 •Filters out Oxygen from Ambient Air to Create...Supply System •Supply System Must Be Perfectly Clean •Best Cleaning Solutions Freon CFC-113 and HCFC-141b •On-Board Oxygen Generating System Replaced

Giant Reed (Arundo donax): A Climax Community of the Riparian Zone

Treesearch

John P. Rieger; D. Ann Kreager

1989-01-01

Active management of coastal streams is needed to ensure the continued existence of significant riparian systems in Southern California. The concept of a dynamic self-replacing plant community is no longer a truism there. In the past decades one exotic species in particular, the Giant Reed (Arundo donax L.) has had an ever-increasing negative role in...

Cheating cheatgrass: New research to combat a wily invasive weed

Treesearch

Gail Wells

2012-01-01

Cheatgrass and its cousin, red brome, are exotic annual grasses that have invaded and altered ecosystem dynamics in more than 41 million acres of desert shrublands between the Rockies and the Cascade-Sierra chain. A fungus naturally associated with these Bromus species has been found lethal to the plants' soil-banked dormant seeds. Supported by the Joint Fire...

Mechanisms and time-resolved dynamics for trihydrogen cation (H 3 +) formation from organic molecules in strong laser fields

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

Ekanayake, Nagitha; Nairat, Muath; Kaderiya, Balram

Strong-field laser-matter interactions often lead to exotic chemical reactions. Trihydrogen cation formation from organic molecules is one such case that requires multiple bonds to break and form. Here, we present evidence for the existence of two different reaction pathways for H 3 + formation from organic molecules irradiated by a strong-field laser. Assignment of the two pathways was accomplished through analysis of femtosecond time-resolved strong-field ionization and photoion-photoion coincidence measurements carried out on methanol isotopomers, ethylene glycol, and acetone. Ab initio molecular dynamics simulations suggest the formation occurs via two steps: the initial formation of a neutral hydrogen molecule, followedmore » by the abstraction of a proton from the remaining CHOH 2+ fragment by the roaming H 2 molecule. This reaction has similarities to the H 2+H 2 + mechanism leading to formation of H 3 + in the universe. These exotic chemical reaction mechanisms, involving roaming H 2 molecules, are found to occur in the ~100 fs timescale. Roaming molecule reactions may help to explain unlikely chemical processes, involving dissociation and formation of multiple chemical bonds, occurring under strong laser fields.« less

On the dynamics of exotic matter: Towards creation of Perpetuum Mobile of third kind

NASA Astrophysics Data System (ADS)

Ivanov, Pavel

2009-09-01

The one-dimensional dynamics of a classical ideal ‘exotic’ fluid with equation of state p=p(γ)<0 violating the weak energy condition is discussed. Under certain assumptions it is shown that the well-known Hwa-Bjorken exact solution of one-dimensional relativistic hydrodynamics is confined within the future/past light cone. It is also demonstrated that the total energy of such a solution is equal to zero and that there are regions within the light cone with negative (-) and positive (+) total energies. For certain equations of state there is a continuous energy transfer from the (-)-regions to the (+)-regions resulting in indefinite growth of energy in the (+)-regions with time, which may be interpreted as action of a specific ‘Perpetuum Mobile’ (Perpetuum Motion). It is speculated that if it is possible to construct a three-dimensional non-stationary flow of an exotic fluid having a finite negative value of energy such a situation would also occur. Such a flow may continuously transfer positive energy to gravitational waves, resulting in a runaway. It is conjectured that theories plagued by such solutions should be discarded as inherently unstable.

Mechanisms and time-resolved dynamics for trihydrogen cation (H 3 +) formation from organic molecules in strong laser fields

DOE PAGES

Ekanayake, Nagitha; Nairat, Muath; Kaderiya, Balram; ...

2017-07-05

Strong-field laser-matter interactions often lead to exotic chemical reactions. Trihydrogen cation formation from organic molecules is one such case that requires multiple bonds to break and form. Here, we present evidence for the existence of two different reaction pathways for H 3 + formation from organic molecules irradiated by a strong-field laser. Assignment of the two pathways was accomplished through analysis of femtosecond time-resolved strong-field ionization and photoion-photoion coincidence measurements carried out on methanol isotopomers, ethylene glycol, and acetone. Ab initio molecular dynamics simulations suggest the formation occurs via two steps: the initial formation of a neutral hydrogen molecule, followedmore » by the abstraction of a proton from the remaining CHOH 2+ fragment by the roaming H 2 molecule. This reaction has similarities to the H 2+H 2 + mechanism leading to formation of H 3 + in the universe. These exotic chemical reaction mechanisms, involving roaming H 2 molecules, are found to occur in the ~100 fs timescale. Roaming molecule reactions may help to explain unlikely chemical processes, involving dissociation and formation of multiple chemical bonds, occurring under strong laser fields.« less

9 CFR 352.3 - Application by official exotic animal establishment for inspection services.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... (a) Any person desiring to process an exotic animal, exotic animal carcasses, exotic animal meat and... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Application by official exotic animal establishment for inspection services. 352.3 Section 352.3 Animals and Animal Products FOOD SAFETY AND...

Observation of a shape resonance of the positronium negative ion

PubMed Central

Michishio, Koji; Kanai, Tsuneto; Kuma, Susumu; Azuma, Toshiyuki; Wada, Ken; Mochizuki, Izumi; Hyodo, Toshio; Yagishita, Akira; Nagashima, Yasuyuki

2016-01-01

When an electron binds to its anti-matter counterpart, the positron, it forms the exotic atom positronium (Ps). Ps can further bind to another electron to form the positronium negative ion, Ps− (e−e+e−). Since its constituents are solely point-like particles with the same mass, this system provides an excellent testing ground for the three-body problem in quantum mechanics. While theoretical works on its energy level and dynamics have been performed extensively, experimental investigations of its characteristics have been hampered by the weak ion yield and short annihilation lifetime. Here we report on the laser spectroscopy study of Ps−, using a source of efficiently produced ions, generated from the bombardment of slow positrons onto a Na-coated W surface. A strong shape resonance of 1Po symmetry has been observed near the Ps (n=2) formation threshold. The resonance energy and width measured are in good agreement with the result of three-body calculations. PMID:26983496

Soil ecosystem function under native and exotic plant assemblages as alternative states of successional grasslands

NASA Astrophysics Data System (ADS)

Spirito, Florencia; Yahdjian, Laura; Tognetti, Pedro M.; Chaneton, Enrique J.

2014-01-01

Old fields often become dominated by exotic plants establishing persistent community states. Ecosystem functioning may differ widely between such novel communities and the native-dominated counterparts. We evaluated soil ecosystem attributes in native and exotic (synthetic) grass assemblages established on a newly abandoned field, and in remnants of native grassland in the Inland Pampa, Argentina. We asked whether exotic species alter soil functioning through the quality of the litter they shed or by changing the decomposition environment. Litter decomposition of the exotic dominant Festuca arundinacea in exotic assemblages was faster than that of the native dominant Paspalum quadrifarium in native assemblages and remnant grasslands. Decomposition of a standard litter (Triticum aestivum) was also faster in exotic assemblages than in native assemblages and remnant grasslands. In a common garden, F. arundinacea showed higher decay rates than P. quadrifarium, which reflected the higher N content and lower C:N of the exotic grass litter. Soil respiration rates were higher in the exotic than in the native assemblages and remnant grasslands. Yet there were no significant differences in soil N availability or net N mineralization between exotic and native assemblages. Our results suggest that exotic grass dominance affected ecosystem function by producing a more decomposable leaf litter and by increasing soil decomposer activity. These changes might contribute to the extended dominance of fast-growing exotic grasses during old-field succession. Further, increased organic matter turnover under novel, exotic communities could reduce the carbon storage capacity of the system in the long term.

Reciprocal Effects of Litter from Exotic and Congeneric Native Plant Species via Soil Nutrients

PubMed Central

Meisner, Annelein; de Boer, Wietse; Cornelissen, Johannes H. C.; van der Putten, Wim H.

2012-01-01

Invasive exotic plant species are often expected to benefit exclusively from legacy effects of their litter inputs on soil processes and nutrient availability. However, there are relatively few experimental tests determining how litter of exotic plants affects their own growth conditions compared to congeneric native plant species. Here, we test how the legacy of litter from three exotic plant species affects their own performance in comparison to their congeneric natives that co-occur in the invaded habitat. We also analyzed litter effects on soil processes. In all three comparisons, soil with litter from exotic plant species had the highest respiration rates. In two out of the three exotic-native species comparisons, soil with litter from exotic plant species had higher inorganic nitrogen concentrations than their native congener, which was likely due to higher initial litter quality of the exotics. When litter from an exotic plant species had a positive effect on itself, it also had a positive effect on its native congener. We conclude that exotic plant species develop a legacy effect in soil from the invaded range through their litter inputs. This litter legacy effect results in altered soil processes that can promote both the exotic plant species and their native congener. PMID:22359604

TITAN's multiple-reflection time-of-flight isobar separator

NASA Astrophysics Data System (ADS)

Reiter, Moritz Pascal; Titan Collaboration

2016-09-01

At the ISAC facility located at TRIUMF exotic nuclei are produced by the ISOL method. Exotic nuclei are separated by a magnetic separator and transported to TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). TITAN is a system of multiple ion traps for high precision mass measurements and in-trap decay spectroscopy. Although ISAC can deliver some of the highest yields for even many of the most exotic species many measurements suffer from a strong isobaric background. This background often prevents the high precision measurement of the species of interest. To overcome this limitation an additional isobar separator based on the Multiple-Reflection Time-Of-Flight Mass Spectrometry (MR-TOF-MS) technique has been developed for TITAN. Mass selection is achieved using dynamic re-trapping of the species of interest after a time-of-flight analysis in an electrostatic isochronous reflector system. Additionally the MR-TOF-MS will, on its own, enable mass measurements of very short-lived nuclides that are weakly produced. Being able to measure all isobars of a given mass number at the same time the MR-TOF-MS can be used for beam diagnostics or determination of beam compositions. Results from the offline commissioning showing mass resolving power and separation power will be presented.

A new perspective on trait differences between native and invasive exotic plants: reply to critique

USDA-ARS?s Scientific Manuscript database

A meta-analysis contrasting morphological and physiological traits of invasive species and native species was conducted using data acquired from journal articles published between the years 1995 and 2010. This study (Leffler et al. 2014, Ecology 95:298-305), generated a comment from Dawson et al. (...

Nursery performance of American and Chinese chestnuts and backcross generations in commercial tree nurseries

Treesearch

Stacy L. Clark; Scott E. Schlarbaum; Arnold M. Saxton; Fred V. Hebard

2012-01-01

The American chestnut [Castanea dentata (Marsh.) Borkh.] was decimated by an exotic fungus [Cryphonectria parasitica (Murr.) Barr] in the early 1900s. Breeding efforts with American and Chinese chestnuts (C. mollissima Blume) produced putatively blight-resistant progeny (BC3F3) in 2007. We compared two nut size...

Search for New T' particles in final states with large jet multiplicities and missing transverse energy in p p collisions at sqrt[s] = 1.96 TeV.

PubMed

Aaltonen, T; Álvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Apresyan, A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bauer, G; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Bentivegna, M; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Brisuda, A; Bromberg, C; Brucken, E; Bucciantonio, M; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Dagenhart, D; d'Ascenzo, N; Datta, M; de Barbaro, P; De Cecco, S; De Lorenzo, G; Dell'orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, M; Dorigo, T; Ebina, K; Elagin, A; Eppig, A; Erbacher, R; Errede, D; Errede, S; Ershaidat, N; Eusebi, R; Fang, H C; Farrington, S; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Funakoshi, Y; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Grinstein, S; Grosso-Pilcher, C; Group, R C; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Halkiadakis, E; Hamaguchi, A; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Hewamanage, S; Hidas, D; Hocker, A; Hopkins, W; Horn, D; Hou, S; Hughes, R E; Hurwitz, M; Husemann, U; Hussain, N; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirby, M; Klimenko, S; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kuhr, T; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lecompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leo, S; Leone, S; Lewis, J D; Limosani, A; Lin, C-J; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, Q; Liu, T; Lockwitz, S; Lockyer, N S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maeshima, K; Makhoul, K; Maksimovic, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Martínez, M; Martínez-Ballarín, R; Mastrandrea, P; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Potamianos, K; Poukhov, O; Prokoshin, F; Pronko, A; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Rao, K; Redondo, I; Renton, P; Rescigno, M; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rubbo, F; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Sakurai, Y; Santi, L; Sartori, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shreyber, I; Simonenko, A; Sinervo, P; Sissakian, A; Sliwa, K; Smith, J R; Snider, F D; Soha, A; Somalwar, S; Sorin, V; Squillacioti, P; Stancari, M; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Tu, Y; Ukegawa, F; Uozumi, S; Varganov, A; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Vizán, J; Vogel, M; Volpi, G; Wagner, P; Wagner, R L; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Wick, F; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamaoka, J; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zucchelli, S

2011-11-04

We present a search for a new particle T' decaying to a top quark via T' → t + X, where X goes undetected. We use a data sample corresponding to 5.7 fb(-1) of integrated luminosity of p p collisions with sqrt[s] = 1.96 TeV, collected at Fermilab Tevatron by the CDF II detector. Our search for pair production of T' is focused on the hadronic decay channel, pp → T'T' → tt + XX → bqq b qq + XX. We interpret our results in terms of a model where T' is an exotic fourth generation quark and X is a dark matter particle. The data are consistent with standard model expectations. We set a limit on the generic production of T'T' → tt + XX, excluding the fourth generation exotic quarks T' at 95% confidence level up to m(T') = 400 GeV/c(2) for m(X) ≤ 70 GeV/c(2).

Oxygen-Free Biochemistry: The Putative CHN Foundation for Exotic Life in a Hydrocarbon World?

PubMed

Lv, Kong-Peng; Norman, Lucy; Li, Yi-Liang

2017-11-01

Since Earth's biochemistry is carbon-based and water-borne, the main strategies for searching for life elsewhere are "follow the carbon" and "follow the water." Recently, however, there is a growing focus on the prospect that putative exotic life on other planets could rely on unearthly biochemistries. Here, we hypothesize a novel oxygen-free organic chemistry for supporting potential exotic biosystems, which is named CHN biochemistry. This oxygen-free CHN biochemistry starts from simple oxygen-free species (including hydrocarbons, hydrogen cyanide, and nitriles) and produces a range of functional macromolecules that may function in similar ways to terran macromolecules, such as sugars (cyanosugars), acids (cyanoacids), amino acids (amino cyanoacids), and nucleobases (cyanonucleobases). These CHN macromolecules could further interact with each other to generate higher "cyanoester" and "cyanoprotein" systems. In addition, theoretical calculations indicate that the energy changes of some reactions are consistent with their counterparts in Earth's biochemistry. The CHN biochemistry-based life would be applicable in habitats with a low bioavailability of oxygen, such as the alkane lakes of Titan and non-aquatic liquids on extrasolar bodies. Key Words: Oxygen-free biochemistry-Titan-Hydrocarbons-Hydrogen cyanide-Nitriles. Astrobiology 17, 1173-1181.

A recipe for echoes from exotic compact objects

NASA Astrophysics Data System (ADS)

Mark, Zachary; Zimmerman, Aaron; Du, Song Ming; Chen, Yanbei

2017-10-01

Gravitational wave astronomy provides an unprecedented opportunity to test the nature of black holes and search for exotic, compact alternatives. Recent studies have shown that exotic compact objects (ECOs) can ring down in a manner similar to black holes, but can also produce a sequence of distinct pulses resembling the initial ringdown. These "echoes" would provide definite evidence for the existence of ECOs. In this work we study the generation of these echoes in a generic, parametrized model for the ECO, using Green's functions. We show how to reprocess radiation in the near-horizon region of a Schwarzschild black hole into the asymptotic radiation from the corresponding source in an ECO spacetime. Our methods allow us to understand the connection between distinct echoes and ringing at the resonant frequencies of the compact object. We find that the quasinormal mode ringing in the black hole spacetime plays a central role in determining the shape of the first few echoes. We use this observation to develop a simple template for echo waveforms. This template preforms well over a variety of ECO parameters, and with improvements may prove useful in the analysis of gravitational waves.

Managing shifting species: Ancient DNA reveals conservation conundrums in a dynamic world.

PubMed

Waters, Jonathan M; Grosser, Stefanie

2016-11-01

The spread of exotic species represents a major driver of biological change across the planet. While dispersal and colonization are natural biological processes, we suggest that the failure to recognize increasing rates of human-facilitated self-introductions may represent a threat to native lineages. Notably, recent biogeographic analyses have revealed numerous cases of biological range shifts in response to anthropogenic impacts and climate change. In particular, ancient DNA analyses have revealed several cases in which lineages traditionally thought to be long-established "natives" are in fact recent colonizers. Such range expansion events have apparently occurred in response to human-mediated native biodiversity declines and ecosystem change, particularly in recently colonized, isolated ecosystems such as New Zealand. While such events can potentially boost local biodiversity, the spread of exotic lineages may also hasten the decline of indigenous species, so it is essential that conservation managers recognize these rapid biotic shifts.​. © 2016 WILEY Periodicals, Inc.

Mitigating exotic impacts: restoring native deer mouse populations elevated by an exotic food subsidy

Treesearch

Dean E. Pearson; Robert J. Fletcher

2008-01-01

The threat posed by exotic organisms to native systems has led to extensive research on exotic invaders, yet management of invasives has progressed relatively slowly. This is partly due to poor understanding of how exotic species management influences native organisms. To address this shortfall, we experimentally evaluated the efficacy of an invasives management tool...

When relationships estimated in the past cannot be used to predict the future: using mechanistic models to predict landscape ecological dynamics in a changing world

Treesearch

Eric J. Gustafson

2013-01-01

Researchers and natural resource managers need predictions of how multiple global changes (e.g., climate change, rising levels of air pollutants, exotic invasions) will affect landscape composition and ecosystem function. Ecological predictive models used for this purpose are constructed using either a mechanistic (process-based) or a phenomenological (empirical)...

Are Local Filters Blind to Provenance? Ant Seed Predation Suppresses Exotic Plants More than Natives

PubMed Central

Pearson, Dean E.; Icasatti, Nadia S.; Hierro, Jose L.; Bird, Benjamin J.

2014-01-01

The question of whether species’ origins influence invasion outcomes has been a point of substantial debate in invasion ecology. Theoretically, colonization outcomes can be predicted based on how species’ traits interact with community filters, a process presumably blind to species’ origins. Yet, exotic plant introductions commonly result in monospecific plant densities not commonly seen in native assemblages, suggesting that exotic species may respond to community filters differently than natives. Here, we tested whether exotic and native species differed in their responses to a local community filter by examining how ant seed predation affected recruitment of eighteen native and exotic plant species in central Argentina. Ant seed predation proved to be an important local filter that strongly suppressed plant recruitment, but ants suppressed exotic recruitment far more than natives (89% of exotic species vs. 22% of natives). Seed size predicted ant impacts on recruitment independent of origins, with ant preference for smaller seeds resulting in smaller seeded plant species being heavily suppressed. The disproportionate effects of provenance arose because exotics had generally smaller seeds than natives. Exotics also exhibited greater emergence and earlier peak emergence than natives in the absence of ants. However, when ants had access to seeds, these potential advantages of exotics were negated due to the filtering bias against exotics. The differences in traits we observed between exotics and natives suggest that higher-order introduction filters or regional processes preselected for certain exotic traits that then interacted with the local seed predation filter. Our results suggest that the interactions between local filters and species traits can predict invasion outcomes, but understanding the role of provenance will require quantifying filtering processes at multiple hierarchical scales and evaluating interactions between filters. PMID:25099535

Co‐occurrence dynamics of endangered Lower Keys marsh rabbits and free‐ranging domestic cats: Prey responses to an exotic predator removal program

USGS Publications Warehouse

Cove, Michael V.; Gardner, Beth; Simons, Theodore R.; O'Connell, Allan F.

2018-01-01

The Lower Keys marsh rabbit (Sylvilagus palustris hefneri) is one of many endangered endemic species of the Florida Keys. The main threats are habitat loss and fragmentation from sea‐level rise, development, and habitat succession. Exotic predators such as free‐ranging domestic cats (Felis catus) pose an additional threat to these endangered small mammals. Management strategies have focused on habitat restoration and exotic predator control. However, the effectiveness of predator removal and the effects of anthropogenic habitat modifications and restoration have not been evaluated. Between 2013 and 2015, we used camera traps to survey marsh rabbits and free‐ranging cats at 84 sites in the National Key Deer Refuge, Big Pine Key, Florida, USA. We used dynamic occupancy models to determine factors associated with marsh rabbit occurrence, colonization, extinction, and the co‐occurrence of marsh rabbits and cats during a period of predator removal. Rabbit occurrence was positively related to freshwater habitat and patch size, but was negatively related to the number of individual cats detected at each site. Furthermore, marsh rabbit colonization was negatively associated with relative increases in the number of individual cats at each site between survey years. Cat occurrence was negatively associated with increasing distance from human developments. The probability of cat site extinction was positively related to a 2‐year trapping effort, indicating that predator removal reduced the cat population. Dynamic co‐occurrence models suggested that cats and marsh rabbits co‐occur less frequently than expected under random conditions, whereas co‐detections were site and survey‐specific. Rabbit site extinction and colonization were not strongly conditional on cat presence, but corresponded with a negative association. Our results suggest that while rabbits can colonize and persist at sites where cats occur, it is the number of individual cats at a site that more strongly influences rabbit occupancy and colonization. These findings indicate that continued predator management would likely benefit endangered small mammals as they recolonize restored habitats.

The Soreq Applied Research Accelerator Facility (SARAF): Overview, research programs and future plans

NASA Astrophysics Data System (ADS)

Mardor, Israel; Aviv, Ofer; Avrigeanu, Marilena; Berkovits, Dan; Dahan, Adi; Dickel, Timo; Eliyahu, Ilan; Gai, Moshe; Gavish-Segev, Inbal; Halfon, Shlomi; Hass, Michael; Hirsh, Tsviki; Kaiser, Boaz; Kijel, Daniel; Kreisel, Arik; Mishnayot, Yonatan; Mukul, Ish; Ohayon, Ben; Paul, Michael; Perry, Amichay; Rahangdale, Hitesh; Rodnizki, Jacob; Ron, Guy; Sasson-Zukran, Revital; Shor, Asher; Silverman, Ido; Tessler, Moshe; Vaintraub, Sergey; Weissman, Leo

2018-05-01

The Soreq Applied Research Accelerator Facility (SARAF) is under construction in the Soreq Nuclear Research Center at Yavne, Israel. When completed at the beginning of the next decade, SARAF will be a user facility for basic and applied nuclear physics, based on a 40 MeV, 5 mA CW proton/deuteron superconducting linear accelerator. Phase I of SARAF (SARAF-I, 4 MeV, 2 mA CW protons, 5 MeV 1 mA CW deuterons) is already in operation, generating scientific results in several fields of interest. The main ongoing program at SARAF-I is the production of 30 keV neutrons and measurement of Maxwellian Averaged Cross Sections (MACS), important for the astrophysical s-process. The world leading Maxwellian epithermal neutron yield at SARAF-I (5 × 10^{10} epithermal neutrons/s), generated by a novel Liquid-Lithium Target (LiLiT), enables improved precision of known MACSs, and new measurements of low-abundance and radioactive isotopes. Research plans for SARAF-II span several disciplines: precision studies of beyond-Standard-Model effects by trapping light exotic radioisotopes, such as 6He, 8Li and 18, 19, 23Ne, in unprecedented amounts (including meaningful studies already at SARAF-I); extended nuclear astrophysics research with higher energy neutrons, including generation and studies of exotic neutron-rich isotopes relevant to the rapid (r-) process; nuclear structure of exotic isotopes; high energy neutron cross sections for basic nuclear physics and material science research, including neutron induced radiation damage; neutron based imaging and therapy; and novel radiopharmaceuticals development and production. In this paper we present a technical overview of SARAF-I and II, including a description of the accelerator and its irradiation targets; a survey of existing research programs at SARAF-I; and the research potential at the completed facility (SARAF-II).

Patterns of plant invasions: A case example in native species hotspots and rare habitats

USGS Publications Warehouse

Stohlgren, T.J.; Otsuki, Yuka; Villa, C.A.; Lee, M.; Belnap, J.

2001-01-01

Land managers require landscape-scale information on where exotic plant species have successfully established, to better guide research, control, and restoration efforts. We evaluated the vulnerability of various habitats to invasion by exotic plant species in a 100,000 ha area in the southeast corner of Grand Staircase-Escalante National Monument, Utah. For the 97 0.1-ha plots in 11 vegetation types, exotic species richness (log10) was strongly negatively correlated to the cover of cryptobiotic soil crusts (r = −0.47, P < 0.001), and positively correlated to native species richness (r = 0.22, P < 0.03), native species cover (r = 0.23, P < 0.05), and total nitrogen in the soil (r = 0.40, P < 0.001). Exotic species cover was strongly positively correlated to exotic species richness (r = 0.68, P < 0.001). Only 6 of 97 plots did not contain at least one exotic species. Exotic species richness was particularly high in locally rare, mesic vegetation types and nitrogen rich soils. Dry, upland plots (n = 51) had less than half of the exotic species richness and cover compared to plots (n = 45) in washes and lowland depressions that collect water intermittently. Plots dominated by trees had significantly greater native and exotic species richness compared to plots dominated by shrubs. For the 97 plots combined, 33% of the variance in exotic species richness could be explained by a positive relationship with total plant cover, and negative relationships with the cover of cryptobiotic crusts and bare ground. There are several reasons for concern: (1) Exotic plant species are invading hot spots of native plant diversity and rare/unique habitats. (2) The foliar cover of exotic species was greatest in habitats that had been invaded by several exotic species.(3) Continued disturbance of fragile cryptobiotic crusts by livestock, people, and vehicles may facilitate the further invasion of exotic plant species.

Long-term deer exclusion has complex effects on a suburban forest understory

USGS Publications Warehouse

Faison, Edward K.; Foster, David R.; DeStefano, Stephen

2016-01-01

Herbivory by deer is one of the leading biotic disturbances on forest understories (i.e., herbs, small shrubs, and small tree seedlings). A large body of research has reported declines in height, abundance, and reproductive capacity of forbs and woody plants coupled with increases in abundance of graminoids, ferns, and exotic species due to deer herbivory. Less clear is the extent to which (and the direction in which) deer alter herbaceous layer diversity, where much of the plant diversity in a forest occurs. We examined the effect of 15 y of deer exclusion on the understory of a suburban hardwood forest in Connecticut exposed to decades of intensive herbivory by white-tailed deer (Odocoileus virginianus). We compared species richness (at subplot and plot scale), individual species and life form group abundance (% cover), and community composition between grazed and exclosure plots, as well as between mesic and wet soil blocks. Forb cover was more than twice as abundant in exclosure as in grazed plots, whereas sedge (Carex spp.) cover was 28 times more abundant, and exotic species cover generally higher in grazed than in exclosure plots. Native and exotic species richness were both higher in grazed than exclosure plots at the subplot scale, and native herbaceous richness was higher in grazed plots at both spatial scales. In contrast, native shrub richness increased with deer exclusion at the plot scale. Our results suggest that deer exclusion had contrasting effects on species richness, depending on plant life form, but that overall richness of both exotic and native plants declined with deer exclusion. In addition, site heterogeneity remained an important driver of vegetation dynamics even in the midst of high deer densities.

Experimental Test of Preferences for an Invasive Prey by an Endangered Predator: Implications for Conservation.

PubMed

Wilcox, Rebecca C; Fletcher, Robert J

2016-01-01

Identifying impacts of exotic species on native populations is central to ecology and conservation. Although the effects of exotic predators on native prey have received much attention, the role of exotic prey on native predators is poorly understood. Determining if native predators actively prefer invasive prey over native prey has implications for interpreting invasion impacts, identifying the presence of evolutionary traps, and predator persistence. One of the world's most invasive species, Pomacea maculata, has recently established in portions of the endangered Everglade snail kite's (Rostrhamus sociabilis plumbeus) geographic range. Although these exotic snails could provide additional prey resources, they are typically much larger than the native snail, which can lead to lower foraging success and the potential for diminished energetic benefits in comparison to native snails. Nonetheless, snail kites frequently forage on exotic snails. We used choice experiments to evaluate snail kite foraging preference in relation to exotic species and snail size. We found that snail kites do not show a preference for native or exotic snails. Rather, snail kites generally showed a preference for medium-sized snails, the sizes reflective of large native snails. These results suggest that while snail kites frequently forage on exotic snails in the wild, this behavior is likely driven simply by the abundance of exotic snails rather than snail kites preferring exotics. This lack of preference offers insights to hypotheses regarding effects of exotic species, guidance regarding habitat and invasive species management, and illustrates how native-exotic relationships can be misleading in the absence of experimental tests of such interactions.

Ability of a Generalist Seed Beetle to Colonize an Exotic Host: Effects of Host Plant Origin and Oviposition Host.

PubMed

Amarillo-Suárez, A; Repizo, A; Robles, J; Diaz, J; Bustamante, S

2017-08-01

The colonization of an exotic species by native herbivores is more likely to occur if that herbivore is a generalist. There is little information on the life-history mechanisms used by native generalist insects to colonize exotic hosts and how these mechanisms are affected by host properties. We examined the ability of the generalist seed beetle Stator limbatus Horn to colonize an exotic species. We compared its host preference, acceptability, performance, and egg size when ovipositing and developing on two native (Pithecellobium dulce (Roxb.) Benth and Senegalia riparia (Kunth)) and one exotic legume species (Leucaena leucocephala (Lam.)). We also analyzed the seed chemistry. We found that females recognize the exotic species as an unfavorable host for larval development and that they delayed oviposition and laid fewer and larger eggs on the exotic species than on the native species. Survivorship on the exotic host was 0%. Additionally, seeds of the native species contain five chemical compounds that are absent in the exotic species, and the exotic species contains three sterols, which are absent in the native legumes. Genetically based differences between beetles adapted to different hosts, plastic responses toward new hosts, and chemical differences among seeds are important in host colonization and recognition of the exotic host. In conclusion, the generalist nature of S. limbatus does not influence its ability to colonize L. leucocephala. Explanations for the colonization of exotic hosts by generalist native species and for the success of invasive species must be complemented with studies measuring local adaptation and plasticity.

Differences in Leaf Flammability, Leaf Traits and Flammability-Trait Relationships between Native and Exotic Plant Species of Dry Sclerophyll Forest

PubMed Central

Murray, Brad R.; Hardstaff, Lyndle K.; Phillips, Megan L.

2013-01-01

The flammability of plant leaves influences the spread of fire through vegetation. Exotic plants invading native vegetation may increase the spread of bushfires if their leaves are more flammable than native leaves. We compared fresh-leaf and dry-leaf flammability (time to ignition) between 52 native and 27 exotic plant species inhabiting dry sclerophyll forest. We found that mean time to ignition was significantly faster in dry exotic leaves than in dry native leaves. There was no significant native-exotic difference in mean time to ignition for fresh leaves. The significantly higher fresh-leaf water content that was found in exotics, lost in the conversion from a fresh to dry state, suggests that leaf water provides an important buffering effect that leads to equivalent mean time to ignition in fresh exotic and native leaves. Exotic leaves were also significantly wider, longer and broader in area with significantly higher specific leaf area–but not thicker–than native leaves. We examined scaling relationships between leaf flammability and leaf size (leaf width, length, area, specific leaf area and thickness). While exotics occupied the comparatively larger and more flammable end of the leaf size-flammability spectrum in general, leaf flammability was significantly correlated with all measures of leaf size except leaf thickness in both native and exotic species such that larger leaves were faster to ignite. Our findings for increased flammability linked with larger leaf size in exotics demonstrate that exotic plant species have the potential to increase the spread of bushfires in dry sclerophyll forest. PMID:24260169

9 CFR 352.13 - Handling and disposal of condemned or other inedible exotic animal products at official exotic...

Code of Federal Regulations, 2010 CFR

2010-01-01

... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.13 Handling and disposal of...

Scaling up from greenhouse resistance to fitness in the field for a host of an emerging forest disease

PubMed Central

Hayden, Katherine J; Garbelotto, Matteo; Dodd, Richard; Wright, Jessica W

2013-01-01

Forest systems are increasingly threatened by emergent, exotic diseases, yet management strategies for forest trees may be hindered by long generation times and scant background knowledge. We tested whether nursery disease resistance and growth traits have predictive value for the conservation of Notholithocarpus densiflorus, the host most susceptible to sudden oak death. We established three experimental populations to assess nursery growth and resistance to Phytophthora ramorum, and correlations between nursery-derived breeding values with seedling survival in a field disease trial. Estimates of nursery traits’ heritability were low to moderate, with lowest estimates for resistance traits. Within the field trial, survival likelihood was increased in larger seedlings and decreased with the development of disease symptoms. The seed-parent family wide likelihood of survival was likewise correlated with family predictors for size and resistance to disease in 2nd year laboratory assays, though not resistance in 1st year leaf assays. We identified traits and seedling families with increased survivorship in planted tanoaks, and a framework to further identify seed parents favored for restoration. The additive genetic variation and seedling disease dynamics we describe hold promise to refine current disease models and expand the understanding of evolutionary dynamics of emergent infectious diseases in highly susceptible hosts. PMID:24062805

Spontaneous hybrids between native and exotic Rubus in the Western United States produce offspring both by apomixis and by sexual recombination

PubMed Central

Clark, L V; Jasieniuk, M

2012-01-01

Facultative asexual reproduction is a trait commonly found in invasive species. With a combination of sexual and asexual reproductive modes, such species may adapt to new environments via sexual recombination during range expansion, while at the same time having the benefits of asexuality such as the maintenance of fitness effects that depend upon heterozygosity. In the Western United States, native species of Rubus (Rosaceae) reproduce sexually whereas exotic naturalized Rubus species reproduce by pseudogamous apomixis. We hypothesized that new asexual lineages of Rubus could arise from hybridization in this range. To detect hybridization between native and exotic Rubus, we genotyped 579 individuals collected across California, Oregon and Washington with eight nuclear microsatellites and two chloroplast markers. Principal Coordinate Analysis and Bayesian clustering revealed a limited amount of hybridization of the native R. ursinus with the exotic R. armeniacus and R. pensilvanicus, as well as cultivated varieties. Genetic distances between these hybrids and their offspring indicated that both R. ursinus × R. armeniacus and R. ursinus × R. pensilvanicus produced a mix of apomictic and sexual seeds, with sexual seeds being more viable. Although neither of these hybrid types is currently considered invasive, they model the early stages of evolution of new invasive lineages, given the potential for fixed heterosis and the generation of novel genotypes. The hybrids also retain the ability to increase their fitness via sexual recombination and natural selection. Mixed reproductive systems such as those described here may be an important step in the evolution of asexual invasive species. PMID:22850699

Scaling up from greenhouse resistance to fitness in the field for a host of an emerging forest disease

Treesearch

Katherine J. Hayden; Matteo Garbelotto; Richard Dodd; Jessica W. Wright

2013-01-01

Forest systems are increasingly threatened by emergent, exotic diseases, yet management strategies for forest trees may be hindered by long generation times and scant background knowledge. We tested whether nursery disease resistance and growth traits have predictive value for the conservation of Notholithocarpus densiflorus, the host most...

Native plants fare better against an introduced competitor with native microbes and lower nitrogen availability

PubMed Central

Shivega, W. Gaya

2017-01-01

Abstract While the soil environment is generally acknowledged as playing a role in plant competition, the relative importance of soil resources and soil microbes in determining outcomes of competition between native and exotic plants has rarely been tested. Resilience of plant communities to invasion by exotic species may depend on the extent to which native and exotic plant performance are mediated by abiotic and biotic components of the soil. We used a greenhouse experiment to compare performance of two native prairie plant species and one exotic species, when grown in intraspecific competition and when each native was grown in interspecific competition with the exotic species, in the presence and absence of a native prairie soil community, and when nitrogen availability was elevated or was maintained at native prairie levels. We found that elevated nitrogen availability was beneficial to the exotic species and had no effect on or was detrimental to the native plant species, that the native microbial community was beneficial to the native plant species and either had no effect or was detrimental to the exotic species and that intraspecific competition was stronger than interspecific competition for the exotic plant species and vice versa for the natives. Our results demonstrate that soil nitrogen availability and the soil microbial community can mediate the strength of competition between native and exotic plant species. We found no evidence for native microbes enhancing the performance of the exotic plant species. Instead, loss of the native soil microbial community appears to reinforce the negative effects of elevated N on native plant communities and its benefits to exotic invasive species. Resilience of plant communities to invasion by exotic plant species is facilitated by the presence of an intact native soil microbial community and weakened by anthropogenic inputs of nitrogen. PMID:28122737

Observation of dynamical vortices after quenches in a system with topology

NASA Astrophysics Data System (ADS)

Fläschner, N.; Vogel, D.; Tarnowski, M.; Rem, B. S.; Lühmann, D.-S.; Heyl, M.; Budich, J. C.; Mathey, L.; Sengstock, K.; Weitenberg, C.

2018-03-01

Topological phases constitute an exotic form of matter characterized by non-local properties rather than local order parameters1. The paradigmatic Haldane model on a hexagonal lattice features such topological phases distinguished by an integer topological invariant known as the first Chern number2. Recently, the identification of non-equilibrium signatures of topology in the dynamics of such systems has attracted particular attention3-6. Here, we experimentally study the dynamical evolution of the wavefunction using time- and momentum-resolved full state tomography for spin-polarized fermionic atoms in driven optical lattices7. We observe the appearance, movement and annihilation of dynamical vortices in momentum space after sudden quenches close to the topological phase transition. These dynamical vortices can be interpreted as dynamical Fisher zeros of the Loschmidt amplitude8, which signal a so-called dynamical phase transition9,10. Our results pave the way to a deeper understanding of the connection between topological phases and non-equilibrium dynamics.

I. Plants

Treesearch

Dean Pearson; Steve Sutherland; Jack Butler; Jane Smith; Carolyn Sieg

2011-01-01

Exotic plants dramatically impact natural communities and disrupt ecosystem services (Mack and others 2000). Although the bulk of current impacts are caused by relatively few exotic species, many additional exotics that are currently established at low levels are increasing in density and distribution and present substantial imminent threats. Additionally, new exotic...

9 CFR 352.2 - Type of service available.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.2 Type of... slaughter of exotic animals, and the preparation, labeling, and certification of the exotic animal meat and...

Naked shell singularities on the brane

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

Seahra, Sanjeev S.

By utilizing nonstandard slicings of 5-dimensional Schwarzschild and Schwarzschild-AdS manifolds based on isotropic coordinates, we generate static and spherically-symmetric braneworld spacetimes containing shell-like naked null singularities. For planar slicings, we find that the brane-matter sourcing the solution is a perfect fluid with an exotic equation of state and a pressure singularity where the brane crosses the bulk horizon. From a relativistic point of view, such a singularity is required to maintain matter infinitesimally above the surface of a black hole. From the point of view of the AdS/CFT conjecture, the singular horizon can be seen as one possible quantum correctionmore » to a classical black hole geometry. Various generalizations of planar slicings are also considered for a Ricci-flat bulk, and we find that singular horizons and exotic matter distributions are common features.« less

Plant litter effects on soil nutrient availability and vegetation dynamics: changes that occur when annual grasses invade shrub-steppe communities

Treesearch

Sheel Bansal; Roger L. Sheley; Bob Blank; Edward A. Vasquez

2014-01-01

Changes in the quantity and quality of plant litter occur in many ecosystems as they are invaded by exotic species, which impact soil nutrient cycling and plant community composition. Such changes in sagebrush-steppe communities are occurring with invasion of annual grasses (AG) into a perennial grass (PG) dominated system. We conducted a 5-year litter manipulation...

A Bosque Riparian Community Index Model for the Middle Rio Grande, Albuquerque, New Mexico: Model Documentation

DTIC Science & Technology

2012-09-01

ecological processes involve the invasion of non-native (exotic) species (USEPA 1999). Through direct biotic interactions (predation and competition) and...indirect interactions ( ecological engineering and habitat modification), invasive species can disrupt the natural population dynamics of native...species (USEPA 1999). Invasives can include noxious plants (i.e., plants that are listed by a state because of their unfavorable economic or ecological

Exotic annual grass alters fuel amounts, continuity and moisture content

USDA-ARS?s Scientific Manuscript database

1. Invasion by exotic plants are one of the most serious threats to native plant communities, biodiversity, and ecosystem functioning. Of particular concern are exotic plants that alter disturbance regimes. Exotic annual grasses are believed to increase wildfire frequency to the detriment of nativ...

Distinctive exotic flavor and aroma compounds of some exotic tropical fruits and berries: a review.

PubMed

Lasekan, Ola; Abbas, Kassim A

2012-01-01

The characteristic flavor of exotic tropical fruits is one of their most attractive attributes to consumers. In this article, the enormous diversity of exotic fruit flavors is reviewed. Classifying some of the exotic fruits into two classes on the basis of whether esters or terpenes predominate in the aroma was also attempted. Indeed, as far as exotic tropical fruits are concerned, the majority of fruits have terpenes predominating in their aroma profile. Some of the fruits in this group are the Amazonian fruits such as pitanga, umbu-caja, camu-camu, garcinia, and bacuri. The ester group is made up of rambutan, durians, star fruit, snake fruit, acerola, tamarind, sapodilla, genipap, soursop, cashew, melon, jackfruit, and cupuacu respectively. Also, the role of sulphur-volatiles in some of the exotic fruits is detailed.

Promoting the exotic pet practice.

PubMed

Harris, Don J

2005-09-01

The marketing and promotion of an exotic pet veterinary practice allows the use of strategies that are not necessarily available in other veterinary disciplines. The advantage that an exotics practice enjoys is that it is able to capitalize not only on the unique nature of the species being attended but also on the specialized features of the hospital itself that make it specifically appropriate in caring for exotic pets. Before marketing, however, comes the responsibility that the practice live up to the claims made in promotional materials. A practice cannot ethically be presented as an "exotics" practice if it is nothing more than a dog and cat facility that is willing to attend to exotic pets. It is the competence of the veterinary staff and the appropriateness of the facility that determines the suitability of the practice for exotics management.

Short-term responses to warming vary between native vs. exotic species and with latitude in an early successional plant community.

PubMed

Welshofer, Kileigh B; Zarnetske, Phoebe L; Lany, Nina K; Read, Quentin D

2018-05-01

Climate change is expected to favor exotic plant species over native species, because exotics tend to have wider climatic tolerances and greater phenological plasticity, and also because climate change may intensify enemy release. Here, we examine direct effects of warming (+ 1.8 °C above ambient) on plant abundance and phenology, as well as indirect effects of warming propagated through herbivores, in two heavily invaded plant communities in Michigan, USA, separated by approximately three degrees latitude. At the northern site, warming increased exotic plant abundance by 19% but decreased native plant abundance by 31%, indicating that exotic species may be favored in a warmer world. Warming also resulted in earlier spring green-up (1.65 ± 0.77 days), earlier flowering (2.18 ± 0.92 days), and greater damage by herbivores (twofold increase), affecting exotic and native species equally. Contrary to expectations, native and exotic plants experienced similar amounts of herbivory. Warming did not have strong ecological effects at the southern site, only resulting in a delay of flowering time by 2.42 ± 0.83 days for both native and exotic species. Consistent with the enemy release hypothesis, exotic plants experienced less herbivory than native plants at the southern site. Herbivory was lower under warming for both exotic and native species at the southern site. Thus, climate warming may favor exotic over native plant species, but the response is likely to depend on additional environmental and individual species' traits.

9 CFR 352.3 - Application by official exotic animal establishment for inspection services.

Code of Federal Regulations, 2011 CFR

2011-01-01

... establishment for inspection services. 352.3 Section 352.3 Animals and Animal Products FOOD SAFETY AND... INSPECTION Exotic Animals § 352.3 Application by official exotic animal establishment for inspection services... meat food products in an establishment under exotic animal inspection service must receive approval of...

9 CFR 352.3 - Application by official exotic animal establishment for inspection services.

Code of Federal Regulations, 2013 CFR

2013-01-01

... establishment for inspection services. 352.3 Section 352.3 Animals and Animal Products FOOD SAFETY AND... INSPECTION Exotic Animals § 352.3 Application by official exotic animal establishment for inspection services... meat food products in an establishment under exotic animal inspection service must receive approval of...

9 CFR 352.3 - Application by official exotic animal establishment for inspection services.

Code of Federal Regulations, 2012 CFR

2012-01-01

... establishment for inspection services. 352.3 Section 352.3 Animals and Animal Products FOOD SAFETY AND... INSPECTION Exotic Animals § 352.3 Application by official exotic animal establishment for inspection services... meat food products in an establishment under exotic animal inspection service must receive approval of...

9 CFR 352.3 - Application by official exotic animal establishment for inspection services.

Code of Federal Regulations, 2014 CFR

2014-01-01

... establishment for inspection services. 352.3 Section 352.3 Animals and Animal Products FOOD SAFETY AND... INSPECTION Exotic Animals § 352.3 Application by official exotic animal establishment for inspection services... meat food products in an establishment under exotic animal inspection service must receive approval of...

Investigation of miniaturized radioisotope thermionic power generation for general use

NASA Astrophysics Data System (ADS)

Duzik, Adam J.; Choi, Sang H.

2016-04-01

Radioisotope thermoelectric generators (RTGs) running off the radioisotope Pu238 are the current standard in deep space probe power supplies. While reliable, these generators are very inefficient, operating at only ~7% efficiency. As an alternative, more efficient radioisotope thermionic emission generators (RTIGs) are being explored. Like RTGs, current RTIGs concepts use exotic materials for the emitter, limiting applicability to space and other niche applications. The high demand for long-lasting mobile power sources would be satisfied if RTIGs could be produced inexpensively. This work focuses on exposing several common materials, such as Al, stainless steel, W, Si, and Cu, to elevated temperatures under vacuum to determine the efficiency of each material as inexpensive replacements for thermoelectric materials.

Novel chemistry of invasive plants: exotic species have more unique metabolomic profiles than native congeners.

PubMed

Macel, Mirka; de Vos, Ric C H; Jansen, Jeroen J; van der Putten, Wim H; van Dam, Nicole M

2014-07-01

It is often assumed that exotic plants can become invasive when they possess novel secondary chemistry compared with native plants in the introduced range. Using untargeted metabolomic fingerprinting, we compared a broad range of metabolites of six successful exotic plant species and their native congeners of the family Asteraceae. Our results showed that plant chemistry is highly species-specific and diverse among both exotic and native species. Nonetheless, the exotic species had on average a higher total number of metabolites and more species-unique metabolites compared with their native congeners. Herbivory led to an overall increase in metabolites in all plant species. Generalist herbivore performance was lower on most of the exotic species compared with the native species. We conclude that high chemical diversity and large phytochemical uniqueness of the exotic species could be indicative of biological invasion potential.

Plant species' origin predicts dominance and response to nutrient enrichment and herbivores in global grasslands.

PubMed

Seabloom, Eric W; Borer, Elizabeth T; Buckley, Yvonne M; Cleland, Elsa E; Davies, Kendi F; Firn, Jennifer; Harpole, W Stanley; Hautier, Yann; Lind, Eric M; MacDougall, Andrew S; Orrock, John L; Prober, Suzanne M; Adler, Peter B; Anderson, T Michael; Bakker, Jonathan D; Biederman, Lori A; Blumenthal, Dana M; Brown, Cynthia S; Brudvig, Lars A; Cadotte, Marc; Chu, Chengjin; Cottingham, Kathryn L; Crawley, Michael J; Damschen, Ellen I; Dantonio, Carla M; DeCrappeo, Nicole M; Du, Guozhen; Fay, Philip A; Frater, Paul; Gruner, Daniel S; Hagenah, Nicole; Hector, Andy; Hillebrand, Helmut; Hofmockel, Kirsten S; Humphries, Hope C; Jin, Virginia L; Kay, Adam; Kirkman, Kevin P; Klein, Julia A; Knops, Johannes M H; La Pierre, Kimberly J; Ladwig, Laura; Lambrinos, John G; Li, Qi; Li, Wei; Marushia, Robin; McCulley, Rebecca L; Melbourne, Brett A; Mitchell, Charles E; Moore, Joslin L; Morgan, John; Mortensen, Brent; O'Halloran, Lydia R; Pyke, David A; Risch, Anita C; Sankaran, Mahesh; Schuetz, Martin; Simonsen, Anna; Smith, Melinda D; Stevens, Carly J; Sullivan, Lauren; Wolkovich, Elizabeth; Wragg, Peter D; Wright, Justin; Yang, Louie

2015-07-15

Exotic species dominate many communities; however the functional significance of species' biogeographic origin remains highly contentious. This debate is fuelled in part by the lack of globally replicated, systematic data assessing the relationship between species provenance, function and response to perturbations. We examined the abundance of native and exotic plant species at 64 grasslands in 13 countries, and at a subset of the sites we experimentally tested native and exotic species responses to two fundamental drivers of invasion, mineral nutrient supplies and vertebrate herbivory. Exotic species are six times more likely to dominate communities than native species. Furthermore, while experimental nutrient addition increases the cover and richness of exotic species, nutrients decrease native diversity and cover. Native and exotic species also differ in their response to vertebrate consumer exclusion. These results suggest that species origin has functional significance, and that eutrophication will lead to increased exotic dominance in grasslands.

Plant species' origin predicts dominance and response to nutrient enrichment and herbivores in global grasslands

PubMed Central

Seabloom, Eric W.; Borer, Elizabeth T.; Buckley, Yvonne M.; Cleland, Elsa E.; Davies, Kendi F.; Firn, Jennifer; Harpole, W. Stanley; Hautier, Yann; Lind, Eric M.; MacDougall, Andrew S.; Orrock, John L.; Prober, Suzanne M.; Adler, Peter B.; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Blumenthal, Dana M.; Brown, Cynthia S.; Brudvig, Lars A.; Cadotte, Marc; Chu, Chengjin; Cottingham, Kathryn L.; Crawley, Michael J.; Damschen, Ellen I.; Dantonio, Carla M.; DeCrappeo, Nicole M.; Du, Guozhen; Fay, Philip A.; Frater, Paul; Gruner, Daniel S.; Hagenah, Nicole; Hector, Andy; Hillebrand, Helmut; Hofmockel, Kirsten S.; Humphries, Hope C.; Jin, Virginia L.; Kay, Adam; Kirkman, Kevin P.; Klein, Julia A.; Knops, Johannes M. H.; La Pierre, Kimberly J.; Ladwig, Laura; Lambrinos, John G.; Li, Qi; Li, Wei; Marushia, Robin; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Morgan, John; Mortensen, Brent; O'Halloran, Lydia R.; Pyke, David A.; Risch, Anita C.; Sankaran, Mahesh; Schuetz, Martin; Simonsen, Anna; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren; Wolkovich, Elizabeth; Wragg, Peter D.; Wright, Justin; Yang, Louie

2015-01-01

Exotic species dominate many communities; however the functional significance of species' biogeographic origin remains highly contentious. This debate is fuelled in part by the lack of globally replicated, systematic data assessing the relationship between species provenance, function and response to perturbations. We examined the abundance of native and exotic plant species at 64 grasslands in 13 countries, and at a subset of the sites we experimentally tested native and exotic species responses to two fundamental drivers of invasion, mineral nutrient supplies and vertebrate herbivory. Exotic species are six times more likely to dominate communities than native species. Furthermore, while experimental nutrient addition increases the cover and richness of exotic species, nutrients decrease native diversity and cover. Native and exotic species also differ in their response to vertebrate consumer exclusion. These results suggest that species origin has functional significance, and that eutrophication will lead to increased exotic dominance in grasslands. PMID:26173623

How Illinois kicked the exotic habit

Treesearch

Francis M. Harty

1998-01-01

For the purpose of this paper, an exotic species is defined as "a plant or animal not native to North America." The history of folly surrounding the premeditated and accidental introduction of exotic animals has been well-documented. In 1963, Dr. E. Raymond Hall wrote, "Introducing exotic species of vertebrates is unscientific, economically wasteful,...

Exotic plant invasions in tropical forests: Patterns and hypotheses

Treesearch

J.S. Denslow; S.J. DeWalt

2008-01-01

In the tropics, exotic plants have been widely introduced for industrial timber, for land reclamation and forage crops, and as ornamentals. In spite of the apparent opportunity for naturalization and spread, invasive exotic plants are scarce in many continental tropical forests. We examine several conditions under which exotic species do pose substantial threats to...

Final Environmental Assessment for Upgrading the Military Operations in Urban Terrain (MOUT) Target Arrays at Avon Park Air Force Range, Florida

DTIC Science & Technology

2008-07-01

exotic plant species. Specifically, natalgrass (Rhynchelytrum repens), cogon grass ( Imperata cylindrica ), both invasive exotics have the potential to...maintenance, the potential for exotic, invasive weeds is likely, especially cogon grass ( Imperata cylindrical). The main concern is that if exotic

Exotic Plants are Invading Southeastern Forests

Treesearch

James H. Miller

1997-01-01

Millions of acres of forest land in the Southeast are being occupied increasingly by non-indigenous harmful plants--exotic invasive plants. They are called exotic invasive plants, because these plants from other continents invade areas in the U.S. faster and more completely than most native species. Invasive exotic plants impede forest productivity, hinder forest-use...

Exotic plant species receive adequate pollinator service despite variable integration into plant-pollinator networks.

PubMed

Thompson, Amibeth H; Knight, Tiffany M

2018-05-01

Both exotic and native plant species rely on insect pollinators for reproductive success, and yet few studies have evaluated whether and how exotic plant species receive services from native pollinators for successful reproduction in their introduced range. Plant species are expected to successfully reproduce in their exotic range if they have low reliance on animal pollinators or if they successfully integrate themselves into resident plant-pollinator networks. Here, we quantify the breeding system, network integration, and pollen limitation for ten focal exotic plant species in North America. Most exotic plant species relied on animal pollinators for reproduction, and these species varied in their network integration. However, plant reproduction was limited by pollen receipt for only one plant species. Our results demonstrate that even poorly integrated exotic plant species can still have high pollination service and high reproductive success. The comprehensive framework considered here provides a method to consider the contribution of plant breeding systems and the pollinator community to pollen limitation, and can be applied to future studies to provide a more synthetic understanding of the factors that determine reproductive success of exotic plant species.

Lake sedimentary DNA accurately records 20th Century introductions of exotic conifers in Scotland.

PubMed

Sjögren, Per; Edwards, Mary E; Gielly, Ludovic; Langdon, Catherine T; Croudace, Ian W; Merkel, Marie Kristine Føreid; Fonville, Thierry; Alsos, Inger Greve

2017-01-01

Sedimentary DNA (sedDNA) has recently emerged as a new proxy for reconstructing past vegetation, but its taphonomy, source area and representation biases need better assessment. We investigated how sedDNA in recent sediments of two small Scottish lakes reflects a major vegetation change, using well-documented 20 th Century plantations of exotic conifers as an experimental system. We used next-generation sequencing to barcode sedDNA retrieved from subrecent lake sediments. For comparison, pollen was analysed from the same samples. The sedDNA record contains 73 taxa (mainly genus or species), all but one of which are present in the study area. Pollen and sedDNA shared 35% of taxa, which partly reflects a difference in source area. More aquatic taxa were recorded in sedDNA, whereas taxa assumed to be of regional rather than local origin were recorded only as pollen. The chronology of the sediments and planting records are well aligned, and sedDNA of exotic conifers appears in high quantities with the establishment of plantations around the lakes. SedDNA recorded other changes in local vegetation that accompanied afforestation. There were no signs of DNA leaching in the sediments or DNA originating from pollen. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

New approaches for sampling and modeling native and exotic plant species richness

USGS Publications Warehouse

Chong, G.W.; Reich, R.M.; Kalkhan, M.A.; Stohlgren, T.J.

2001-01-01

We demonstrate new multi-phase, multi-scale approaches for sampling and modeling native and exotic plant species to predict the spread of invasive species and aid in control efforts. Our test site is a 54,000-ha portion of Rocky Mountain National Park, Colorado, USA. This work is based on previous research wherein we developed vegetation sampling techniques to identify hot spots of diversity, important rare habitats, and locations of invasive plant species. Here we demonstrate statistical modeling tools to rapidly assess current patterns of native and exotic plant species to determine which habitats are most vulnerable to invasion by exotic species. We use stepwise multiple regression and modified residual kriging to estimate numbers of native species and exotic species, as well as probability of observing an exotic species in 30 × 30-m cells. Final models accounted for 62% of the variability observed in number of native species, 51% of the variability observed in number of exotic species, and 47% of the variability associated with observing an exotic species. Important independent variables used in developing the models include geographical location, elevation, slope, aspect, and Landsat TM bands 1-7. These models can direct resource managers to areas in need of further inventory, monitoring, and exotic species control efforts.

Ecosystem response to removal of exotic riparian shrubs and a transition to upland vegetation

USGS Publications Warehouse

Reynolds, Lindsay V.; Cooper, David J.

2011-01-01

Understanding plant community change over time is essential for managing important ecosystems such as riparian areas. This study analyzed historic vegetation using soil seed banks and the effects of riparian shrub removal treatments and channel incision on ecosystem and plant community dynamics in Canyon de Chelly National Monument, Arizona. We focused on how seeds, nutrients, and ground water influence the floristic composition of post-treatment vegetation and addressed three questions: (1) How does pre-treatment soil seed bank composition reflect post-treatment vegetation composition? (2) How does shrub removal affect post-treatment riparian vegetation composition, seed rain inputs, and ground water dynamics? and (3) Is available soil nitrogen increased near dead Russian olive plants following removal and does this influence post-treatment vegetation? We analyzed seed bank composition across the study area, analyzed differences in vegetation, ground water levels, and seed rain between control, cut-stump and whole-plant removal areas, and compared soil nitrogen and vegetation near removed Russian olive to areas lacking Russian olive. The soil seed bank contained more riparian plants, more native and fewer exotic plants than the extant vegetation. Both shrub removal methods decreased exotic plant cover, decreased tamarisk and Russian olive seed inputs, and increased native plant cover after 2 years. Neither method increased ground water levels. Soil near dead Russian olive trees indicated a short-term increase in soil nitrogen following plant removal but did not influence vegetation composition compared to areas without Russian olive. Following tamarisk and Russian olive removal, our study sites were colonized by upland plant species. Many western North American rivers have tamarisk and Russian olive on floodplains abandoned by channel incision, river regulation or both. Our results are widely applicable to sites where drying has occurred and vegetation establishment following shrub removal is likely to be by upland species.

Native plants fare better against an introduced competitor with native microbes and lower nitrogen availability.

PubMed

Gaya Shivega, W; Aldrich-Wolfe, Laura

2017-01-24

While the soil environment is generally acknowledged as playing a role in plant competition, the relative importance of soil resources and soil microbes in determining outcomes of competition between native and exotic plants has rarely been tested. Resilience of plant communities to invasion by exotic species may depend on the extent to which native and exotic plant performance are mediated by abiotic and biotic components of the soil. We used a greenhouse experiment to compare performance of two native prairie plant species and one exotic species, when grown in intraspecific competition and when each native was grown in interspecific competition with the exotic species, in the presence and absence of a native prairie soil community, and when nitrogen availability was elevated or was maintained at native prairie levels. We found that elevated nitrogen availability was beneficial to the exotic species and had no effect on or was detrimental to the native plant species, that the native microbial community was beneficial to the native plant species and either had no effect or was detrimental to the exotic species, and that intraspecific competition was stronger than interspecific competition for the exotic plant species and vice-versa for the natives. Our results demonstrate that soil nitrogen availability and the soil microbial community can mediate the strength of competition between native and exotic plant species. We found no evidence for native microbes enhancing the performance of the exotic plant species. Instead, loss of the native soil microbial community appears to reinforce the negative effects of elevated N on native plant communities and its benefits to exotic invasive species. Resilience of plant communities to invasion by exotic plant species is facilitated by the presence of an intact native soil microbial community and weakened by anthropogenic inputs of nitrogen. Published by Oxford University Press on behalf of the Annals of Botany Company.

Temporal patterns in the abundance and species composition of spiders on host plants of the invasive moth Epiphyas postvittana

USDA-ARS?s Scientific Manuscript database

Generalist predators such as spiders may help mitigate the spread and impact of exotic herbivores. The lack of prey specificity and long generation times of spiders may allow them to persist when pests are scarce, and to limit the growth of pest populations before they reach damaging levels. We exam...

Visualizing the Topologically Induced States of Strongly Correlated Electrons in SmB6

NASA Astrophysics Data System (ADS)

Pirie, Harris; Hoffman, Jennifer E.; He, Yang; Yee, Michael M.; Soumyanarayanan, Anjan; Kim, Dae-Jeong; Fisk, Zachary; Morr, Dirk; Hamidian, Mohammad

The synergy between strong correlations and a topological invariant is predicted to generate exotic topological order, fractional quasiparticles and new platforms for quantum computation. SmB6 is a promising candidate in which interactions generate an insulating state whose gap arises from heavy fermion hybridization of low lying f-states with a Fermi sea. We used spectroscopic imaging scanning tunneling microscopy to visualize the hybridization of distinct crystal-field-split f-levels and the temperature-dependent evolution of an insulating gap spanning the chemical potential. Here, armed with a clear description of the bulk bands, we look within the insulating gap and directly image two dispersing surface states converging to a Dirac point close to the chemical potential. We show that these measurements are consistent with Dirac cones centered at the X and Γ points in the surface Brillouin zone corresponding to a strong topological invariant. The observation of topological states induced from strong correlations establishes SmB6 as an exciting playground for exotic physics. This work was supported by the Moore foundation, Canada Excellence Research Chair Program and the US National Science Foundation under the Grant DMR-1401480.

Exotic pests: major threats to forest health

Treesearch

J. Robert Bridges

1995-01-01

Over 360 exotic forest insects and about 20 exotic diseases have become established in the U.S. Many of these organisms have become serious pests, causing great economic impacts and irreversible ecological harm. Despite efforts to exclude exotic species, forest insects and disease organisms continue to be introduced at a rather rapid rate. In the last few years, one...

Emerging Avenues for Utilization of Exotic Germplasm.

PubMed

Wang, Cuiling; Hu, Songlin; Gardner, Candice; Lübberstedt, Thomas

2017-07-01

Breeders have been successful in increasing crop performance by exploiting genetic diversity over time. However, the reported annual yield increases are not sufficient in view of rapid human population growth and global environmental changes. Exotic germplasm possesses high levels of genetic diversity for valuable traits. However, only a small fraction of naturally occurring genetic diversity is utilized. Moreover, the yield gap between elite and exotic germplasm widens, which increases the effort needed to use exotic germplasm and to identify beneficial alleles and for their introgression. The advent of high-throughput genotyping and phenotyping technologies together with emerging biotechnologies provide new opportunities to explore exotic genetic variation. This review will summarize potential challenges for utilization of exotic germplasm and provide solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Model with a gauged lepton flavor SU(2) symmetry

NASA Astrophysics Data System (ADS)

Chiang, Cheng-Wei; Tsumura, Koji

2018-05-01

We propose a model having a gauged SU(2) symmetry associated with the second and third generations of leptons, dubbed SU(2) μτ , of which U{(1)}_{L_{μ }-L_{τ }} is an Abelian subgroup. In addition to the Standard Model fields, we introduce two types of scalar fields. One exotic scalar field is an SU(2) μτ doublet and SM singlet that develops a nonzero vacuum expectation value at presumably multi-TeV scale to completely break the SU(2) μτ symmetry, rendering three massive gauge bosons. At the same time, the other exotic scalar field, carrying electroweak as well as SU(2) μτ charges, is induced to have a nonzero vacuum expectation value as well and breaks mass degeneracy between the muon and tau. We examine how the new particles in the model contribute to the muon anomalous magnetic moment in the parameter space compliant with the Michel decays of tau.

Dark matter in E 6 Grand unification

NASA Astrophysics Data System (ADS)

Schwichtenberg, Jakob

2018-02-01

We discuss fermionic dark matter in non-supersymmetric E 6 Grand Unification. The fundamental representation of E 6 contains, in addition to the standard model fermions, exotic fermions and we argue that one of them is a viable, interesting dark matter candidate. Its stability is guaranteed by a discrete remnant symmetry, which is an unbroken subgroup of the E 6 gauge symmetry. We compute the symmetry breaking scales and the effect of possible threshold corrections by solving the renormalization group equations numerically after imposing gauge coupling unification. Since the Yukawa couplings of the exotic and the standard model fermions have a common origin, the mass of the dark matter particles is constrained. We find a mass range of 3 · 109 GeV ≲ m DM ≲ 1 · 1013 GeV for our E 6 dark matter candidate, which is within the reach of next-generation direct detection experiments.

Exotic meson decays in the environment with chiral imbalance

NASA Astrophysics Data System (ADS)

Andrianov, A. A.; Andrianov, V. A.; Espriu, D.; Iakubovich, A. V.; Putilova, A. E.

2017-10-01

An emergence of Local Parity Breaking (LPB) in central heavy-ion collisions (HIC) at high energies is discussed. LPB in the fireball can be produced by a difference between the number densities of right- and left-handed chiral fermions (Chiral Imbalance) which is implemented by a chiral (axial) chemical potential. The effective meson lagrangian induced by QCD is extended to the medium with Chiral Imbalance and the properties of light scalar and pseudoscalar mesons (π, α0) are analyzed. It is shown that exotic decays of scalar mesons arise as a result of mixing of π and α0 vacuum states in the presence of chiral imbalance. The pion electromagnetic formfactor obtains an unusual parity-odd supplement which generates a photon polarization asymmetry in pion polarizability. We hope that the above pointed indications of LPB can be identified in experiments on LHC, RHIC, CBM FAIR and NICA accelerators.

Generalized two-dimensional chiral QED: Anomaly and exotic statistics

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

Saradzhev, F.M.

1997-07-01

We study the influence of the anomaly on the physical quantum picture of the generalized chiral Schwinger model defined on S{sup 1}. We show that the anomaly (i) results in the background linearly rising electric field and (ii) makes the spectrum of the physical Hamiltonian nonrelativistic without a massive boson. The physical matter fields acquire exotic statistics. We construct explicitly the algebra of the Poincar{acute e} generators and show that it differs from the Poincar{acute e} one. We exhibit the role of the vacuum Berry phase in the failure of the Poincar{acute e} algebra to close. We prove that, inmore » spite of the background electric field, such phenomenon as the total screening of external charges characteristic for the standard Schwinger model takes place in the generalized chiral Schwinger model, too. {copyright} {ital 1997} {ital The American Physical Society}« less

Greater soil carbon accumulation in deeper soils in native- than in exotic-dominated grassland plantings in the southern Plains

NASA Astrophysics Data System (ADS)

Wilsey, B. J.; Xu, X.; Polley, H. W.; Hofmockel, K. S.

2017-12-01

Global change includes invasion by non-native plant species, and invasion may affect carbon cycling and storage. We tested predictions in central Texas in an experiment that compares mixtures of all exotic or all native species under two summer irrigation treatments (128 or 0 mm) that varies the amount of summer drought stress. At the end of the eighth growing season after establishment, soils were sampled in 10 cm increments to 100 cm depth to determine if soil C differed among treatments, and if treatments differentially affected soil C in deeper soils. Soil C content was significantly (5%) higher under native plantings than under exotic species plantings (P < 0.001). The difference between native and exotic plantings increased with depth, and native plantings had higher soil C in deeper soil layers than in surface layers (native-exotic x depth, P < 0.001). Exotic plantings had decreasing soil C with depth. Soil C:N ratio and δ13C/12C were also significantly affected by native-exotic status, with soils in exotic plots having a significantly greater C4 contribution than native soils. Soil C was unaffected by summer irrigation treatments. Our results suggest that a significant amount of carbon could be sequestered by replacing exotic plant species with native species in the southern Plains, and that more work should be conducted at deeper soil depths. If we had restricted our analyses to surface soil layers (e.g. top 30 cm), we would have failed to detect depth differences between natives and exotics.

Status of the SPES project, a new tool for fundamental and apply science studies with exotic ion beams at LNL

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

Napoli, D. R., E-mail: napoli@lnl.infn.it; Andrighetto, A.; Antonini, P.

SPES, a new accelerator facility for both the production of exotic ion beams and radio-pharmaceuticals, is presently being installed at the Laboratori Nazionali di Legnaro in Italy (LNL). The new cyclotron, which will provide high intensity proton beams for the production of the rare isotopes, has been installed and is now in the commissioning phase. We present here the status of the part of the project devoted to the production and acceleration of fission fragments created in the interaction of an intense proton beam on a production target of UCx. The expected SPES radioactive beams intensities, their quality and theirmore » maximum energies (up to 11 MeV/A for A=130) will permit to perform forefront research in nuclear structure and nuclear dynamics far from the stability valley. Another low energy section of the facility is foreseen for new and challenging research, both in the nuclear physics and in the material science frameworks.« less

Experimental Insights into Ground-State Selection of Quantum XY Pyrochlores

NASA Astrophysics Data System (ADS)

Hallas, Alannah M.; Gaudet, Jonathan; Gaulin, Bruce D.

2018-03-01

Extensive experimental investigations of the magnetic structures and excitations in the XY pyrochlores have been carried out over the past decade. Three families of XY pyrochlores have emerged: Yb2B2O7, Er2B2O7, and, most recently, [Formula: see text]Co2F7. In each case, the magnetic cation (either Yb, Er, or Co) exhibits XY anisotropy within the local pyrochlore coordinates, a consequence of crystal field effects. Materials in these families display rich phase behavior and are candidates for exotic ground states, such as quantum spin ice, and exotic ground-state selection via order-by-disorder mechanisms. In this review, we present an experimental summary of the ground-state properties of the XY pyrochlores, including evidence that they are strongly influenced by phase competition. We empirically demonstrate the signatures for phase competition in a frustrated magnet: multiple heat capacity anomalies, suppressed TN or TC, sample- and pressure-dependent ground states, and unconventional spin dynamics.

Materials discovery at high pressures

NASA Astrophysics Data System (ADS)

Zhang, Lijun; Wang, Yanchao; Lv, Jian; Ma, Yanming

2017-02-01

Pressure is a fundamental thermodynamic variable that can be used to control the properties of materials, because it reduces interatomic distances and profoundly modifies electronic orbitals and bonding patterns. It is thus a versatile tool for the creation of exotic materials not accessible at ambient conditions. Recently developed static and dynamic high-pressure experimental techniques have led to the synthesis of many functional materials with excellent performance: for example, superconductors, superhard materials and high-energy-density materials. Some of these advances have been aided and accelerated by first-principles crystal-structure searching simulations. In this Review, we discuss recent progress in high-pressure materials discovery, placing particular emphasis on the record high-temperature superconductivity in hydrogen sulfide and on nanotwinned cubic boron nitride and diamond, the hardest known materials. Energy materials and exotic chemical materials obtained under high pressures are also discussed. The main drawback of high-pressure materials is their destabilization after pressure release; this problem and its possible solutions are surveyed in the conclusions, which also provide an outlook on the future developments in the field.

Using a botanical garden to assess factors influencing the colonization of exotic woody plants by phyllophagous insects.

PubMed

Kirichenko, Natalia; Kenis, M

2016-09-01

The adoption of exotic plants by indigenous herbivores in the region of introduction can be influenced by numerous factors. A botanical garden in Western Siberia was used to test various hypotheses on the adaptation of indigenous phyllophagous insects to exotic plants invasions, focusing on two feeding guilds, external leaf chewers and leaf miners. A total of 150 indigenous and exotic woody plant species were surveyed for insect damage, abundance and species richness. First, exotic woody plants were much less damaged by chewers and leaf miners than native plants, and the leaf miners' species richness was much lower on exotic than native plants. Second, exotic woody plants having a congeneric species in the region of introduction were more damaged by chewers and hosted a more abundant and species-rich community of leaf miners than plants without native congeneric species. Third, damage by chewers significantly increased with the frequency of planting of exotic host plants outside the botanical garden, and leaf miners' abundance and species richness significantly increased with residence time in the garden. Finally, no significant relationship was found between insect damage or abundance and the origin of the exotic plants. Besides the ecological implications of the results, this study also illustrates the potential of botanical gardens to test ecological hypotheses on biological invasions and insect-plant interactions on a large set of plant species.

How exotic does an exotic information and education initiative about the impact of non-indigenous species need to be?

Treesearch

William F. Hammond

1998-01-01

Providing individuals with effective information, programs, and educational materials about "exotics" or non-indigenous species is generally not a very effective way to get people to act to control, eliminate, and restore damage from exotic species to native ecosystems. Information tends to inform the motivated and educated. Educational research and marketing...

Exotic plant species diversity: Influence of roads and prescribed fire in Arizona ponderosa pine forests

Treesearch

James F. Fowler; Carolyn Hull Sieg; Brett G. Dickson; Victoria Saab

2008-01-01

Many studies have investigated the ecological effects of roads and roadsides as both habitat and dispersal corridors for exotic plant species. Several of these compared roadside exotic species richness and abundance with adjacent interior habitats, but we found no studies of individual exotic species' abundance between the two habitats in the context of prescribed...

How exotic plants integrate into pollination networks

PubMed Central

Stouffer, Daniel B; Cirtwill, Alyssa R; Bascompte, Jordi; Bartomeus, Ignasi

2014-01-01

Summary There is increasing world-wide concern about the impact of the introduction of exotic species on ecological communities. Since many exotic plants depend on native pollinators to successfully establish, it is of paramount importance that we understand precisely how exotic species integrate into existing plant–pollinator communities. In this manuscript, we have studied a global data base of empirical pollination networks to determine whether community, network, species or interaction characteristics can help identify invaded communities. We found that a limited number of community and network properties showed significant differences across the empirical data sets – namely networks with exotic plants present are characterized by greater total, plant and pollinator richness, as well as higher values of relative nestedness. We also observed significant differences in terms of the pollinators that interact with the exotic plants. In particular, we found that specialist pollinators that are also weak contributors to community nestedness are far more likely to interact with exotic plants than would be expected by chance alone. Synthesis. By virtue of their interactions, it appears that exotic plants may provide a key service to a community's specialist pollinators as well as fill otherwise vacant ‘coevolutionary niches’. PMID:25558089

Exploring Unsteady Sail Propulsion in Olympic Class Sailboats

NASA Astrophysics Data System (ADS)

Schutt, Riley; Williamson, C. H. K.

2014-11-01

Unsteady sailing techniques, defined as ``flicking,'' ``roll-tacking'' and ``roll-gybing'' are used by athletes to propel their boats on an Olympic race course faster than using the wind alone. Body weight movements induce unsteady sail motion, increasing driving force and enhancing maneuvering performance. In this research, we explore the dynamics of an Olympic class Laser sailboat equipped with a GPS, IMU, wind sensor, and camera array. The velocity heading of a sailing boat is oriented at an apparent wind angle to the flow. In contrast to classic flapping propulsion, the heaving of the sail section (induced by the sailor's body movement) is not perpendicular to the sail's motion through the air. This leads to an ``exotic heave,'' with components parallel and perpendicular to the incident flow. The characteristic motion is recreated in a towing tank where the vortex structures generated by a representative 2-D sail section are observed, along with a measurement of thrust and lift forces. When combined with turning maneuvers, these heaving sail motions can lead to significant increases in velocity made good, a critical variable used when assessing racing performance.

Sources of Emittance in RF Photocathode Injectors

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

Dowell, David

2016-12-11

Advances in electron beam technology have been central to creating the current generation of x-ray free electron lasers and ultra-fast electron microscopes. These once exotic devices have become essential tools for basic research and applied science. One important beam technology for both is the electron source which, for many of these instruments, is the photocathode RF gun. The invention of the photocathode gun and the concepts of emittance compensation and beam matching in the presence of space charge and RF forces have made these high-quality beams possible. Achieving even brighter beams requires a taking a finer resolution view of themore » electron dynamics near the cathode during photoemission and the initial acceleration of the beam. In addition, the high brightness beam is more sensitive to degradation by the optical aberrations of the gun’s RF and magnetic lenses. This paper discusses these topics including the beam properties due to fundamental photoemission physics, space charge effects close to the cathode, and optical distortions introduced by the RF and solenoid fields. Analytic relations for these phenomena are derived and compared with numerical simulations.« less

Influence of invasive earthworm activity on carbon dynamics in soils from the Aspen Free Air CO2 Enrichment Experiment

NASA Astrophysics Data System (ADS)

Filley, T. R.; Top, S. M.; Hopkins, F. M.

2010-12-01

The influence of CO2-driven increase in net primary productivity on soil organic carbon accrual has received considerable emphasis in ecological literature with conclusions varying from positive, to neutral, to negative. What has been understudied is the coupled role of soil fauna, such as earthworms, in controlling the ultimate fate of new above and below ground plant carbon under elevated CO2. Such considerations are particularly relevant considering that in most northern North American forests earthworms are an exotic organism known to cause significant changes to forest floor chemistry and soil structure, possibly increasing nutrient loss from both soil and leaf litter and mixing litter and humus deep into the mineral soil. The impact of these exotic earthworms on overall soil carbon stabilization is largely unknown but likely a function of both species composition and edaphic soil properties. In this paper we present the initial results of a carbon isotope study (13C, 14C) conducted at the Aspen free air CO2 enrichment (FACE) site, Rhinelander, WI, USA to track allocation and redistribution within the soil of plant litter and root carbon (bulk and biopolymer). Along with litter and soil to 25 cm depth, earthworm populations were quantified, and their gut contents collected for isotopic and plant biopolymer chemistry analysis. Contributions of root vs. leaf input to soil and earthworm fecal matter were derived from differences in the chemical and isotope composition of alkaline CuO-derived lignin and substituted fatty acids (SFA) from cutin and suberin. Our investigation demonstrates the presence of invasive European earthworms, of both litter and surface soil dwelling (epigeic) and deep soil dwelling (endogeic) varieties, whose abundance increases under elevated CO2 conditions. Additionally, the different species show selective vertical movement of new and pre-FACE plant biopolymers indicating dynamics in root and leaf decomposition and burial (down to 30 cm) based upon exotic earthworm activity. The isotopic analysis also demonstrates that these invasive ecosystem engineers are bringing up “old” pre-FACE carbon to the surface, diluting the surface soil carbon isotope signature and potentially causing an apparent “slowing” of the rate of accumulation of FACE derived carbon. Our results highlight the complexity of determining soil C dynamics and the important role of invertebrate ecology in this process.

Real-time dynamics of lattice gauge theories with a few-qubit quantum computer

NASA Astrophysics Data System (ADS)

Martinez, Esteban A.; Muschik, Christine A.; Schindler, Philipp; Nigg, Daniel; Erhard, Alexander; Heyl, Markus; Hauke, Philipp; Dalmonte, Marcello; Monz, Thomas; Zoller, Peter; Blatt, Rainer

2016-06-01

Gauge theories are fundamental to our understanding of interactions between the elementary constituents of matter as mediated by gauge bosons. However, computing the real-time dynamics in gauge theories is a notorious challenge for classical computational methods. This has recently stimulated theoretical effort, using Feynman’s idea of a quantum simulator, to devise schemes for simulating such theories on engineered quantum-mechanical devices, with the difficulty that gauge invariance and the associated local conservation laws (Gauss laws) need to be implemented. Here we report the experimental demonstration of a digital quantum simulation of a lattice gauge theory, by realizing (1 + 1)-dimensional quantum electrodynamics (the Schwinger model) on a few-qubit trapped-ion quantum computer. We are interested in the real-time evolution of the Schwinger mechanism, describing the instability of the bare vacuum due to quantum fluctuations, which manifests itself in the spontaneous creation of electron-positron pairs. To make efficient use of our quantum resources, we map the original problem to a spin model by eliminating the gauge fields in favour of exotic long-range interactions, which can be directly and efficiently implemented on an ion trap architecture. We explore the Schwinger mechanism of particle-antiparticle generation by monitoring the mass production and the vacuum persistence amplitude. Moreover, we track the real-time evolution of entanglement in the system, which illustrates how particle creation and entanglement generation are directly related. Our work represents a first step towards quantum simulation of high-energy theories using atomic physics experiments—the long-term intention is to extend this approach to real-time quantum simulations of non-Abelian lattice gauge theories.

Exotic Forest Insect Pests and Their Impact on Forest Management

Treesearch

Therese M. Poland; Robert A. Haack

2003-01-01

More than 4500 exotic organisms are now established in the United States, of which over 400 are insects that feed on trees and shrubs. While most exotic insects cause little or no damage, a few have become serious pests and have greatly altered native forest ecosystems. Three of the most recently introduced exotic forest pests are the pine shoot beetle, the Asian...

Investigation of Miniaturized Radioisotope Thermionic Power Generation for General Use

NASA Technical Reports Server (NTRS)

Duzik, Adam J.; Choi, Sang H.

2016-01-01

Radioisotope thermoelectric generators (RTGs) running off the radioisotope Pu238 are the current standard in deep space probe power supplies. While reliable, these generators are very inefficient, operating at only approx.7% efficiency. As an alternative, more efficient radioisotope thermionic emission generators (RTIGs) are being explored. Like RTGs, current RTIGs concepts use exotic materials for the emitter, limiting applicability to space and other niche applications. The high demand for long-lasting mobile power sources would be satisfied if RTIGs could be produced inexpensively. This work focuses on exposing several common materials, such as Al, stainless steel, W, Si, and Cu, to elevated temperatures under vacuum to determine the efficiency of each material as inexpensive replacements for thermoelectric materials.

Subalpine vegetation pattern three decades after stand-replacing fire: Effects of landscape context and topography on plant community composition, tree regeneration, and diversity

Treesearch

Jonathan D. Coop; Robert T. Massatti; Anna W. Schoettle

2010-01-01

These subalpine wildfires generated considerable, persistent increases in plant species richness at local and landscape scales, and a diversity of plant communities. The findings suggest that fire suppression in such systems must lead to reduced diversity. Concerns about post-fire invasion by exotic plants appear unwarranted in high-elevation wilderness settings.

Policy Challenges of Accelerating Technological Change: Security Policy and Strategy Implications of Parallel Scientific Revolutions

DTIC Science & Technology

2014-09-01

generation, exotic storage technologies, smart power grid management, and better power sources for directed-energy weapons (DEW). Accessible partner nation...near term will help to mitigate risks and improve outcomes. 2 Forecasting typically extrapolates predictions based...eventually, diminished national power . Within this context, this paper examines policy, legal, ethical, and strategy implications for DoD from the impact

Native weeds and exotic plants: Relationships to disturbance in mixed-grass prairie

USGS Publications Warehouse

Larson, D.L.

2003-01-01

Disturbance frequently is implicated in the spread of invasive exotic plants. Disturbances may be broadly categorized as endogenous (e.g., digging by fossorial animals) or exogenous (e.g., construction and maintenance of roads and trails), just as weedy species may be native or exotic in origin. The objective of this study was to characterize and compare exotic and native weedy plant occurrence in and near three classes of disturbance -digging by prairie dogs (an endogenous disturbance to which native plants have had the opportunity to adapt), paved or gravel roads (an exogenous disturbance without natural precedent), and constructed trails (an exogenous disturbance with a natural precedent in trails created by movement of large mammals) - in three geographically separate national park units. I used plant survey data from the North and South Units of Theodore Roosevelt National Park and Wind Cave National Park in the northern mixed-grass prairie of western North and South Dakota, USA, to characterize the distribution of weedy native and exotic plants with respect to the three disturbance classes as well as areas adjacent to them. There were differences both in the susceptibility of the disturbance classes to invasion and in the distributions of native weeds and exotic species among the disturbance classes. Both exotic and native weedy species richness were greatest in prairie dog towns and community composition there differed most from undisturbed areas. Exotic species were more likely to thrive near roadways, where native weedy species were infrequently encountered. Exotic species were more likely to have spread beyond the disturbed areas into native prairie than were weedy native species. The response of individual exotic plant species to the three types of disturbance was less consistent than that of native weedy species across the three park units.

Responses to invasion and invader removal differ between native and exotic plant groups in a coastal dune.

PubMed

Magnoli, Susan M; Kleinhesselink, Andrew R; Cushman, J Hall

2013-12-01

The spread of exotic, invasive species is a global phenomenon that is recognized as a major source of environmental change. Although many studies have addressed the effects of exotic plants on the communities they invade, few have quantified the effects of invader removal on plant communities, or considered the degree to which different plant groups vary in response to invasion and invader removal. We evaluated the effects of an exotic succulent, iceplant (Carpobrotus edulis), on a coastal dune plant community in northern California, as well as the community responses to its removal. To assess possible mechanisms by which iceplant affects other plants, we also evaluated its above- and belowground influences on the germination and growth of a dominant exotic annual grass, Bromus diandrus. We found that iceplant invasion was associated with reduced native plant cover as well as increased cover and density of some exotic plants-especially exotic annual grasses. However, iceplant removal did not necessarily lead to a reversal of these effects: removal increased the cover and density of both native and exotic species. We also found that B. diandrus grown in iceplant patches, or in soil where iceplant had been removed, had poorer germination and growth than B. diandrus grown in soil not influenced by iceplant. This suggests that the influence of iceplant on this dune plant community occurs, at least in part, due to belowground effects, and that these effects remain after iceplant has been removed. Our study demonstrates the importance of considering how exotic invasive plants affect not only native species, but also co-occurring exotic taxa. It also shows that combining observational studies with removal experiments can lead to important insights into the influence of invaders and the mechanisms of their effects.

Effect of biological soil crusts on seed germination and growth of an exotic and two native plant species in an arid ecosystem.

PubMed

Song, Guang; Li, Xinrong; Hui, Rong

2017-01-01

Biological soil crusts (BSCs) can improve the stability and health of native plant communities in arid ecosystems. However, it is unknown whether BSCs can also inhibit invasions of exotic vascular plants on stabilized reclaimed sand dunes. To answer this question, we conducted a greenhouse experiment to test the effects of cyanobacteria-dominated BSCs on 1) seed germination and biomass of an exotic grass (Stipa glareosa P. Smirn.), and 2) individual biomass of the exotic S. glareosa growing with two native plants, Eragrostis poaeoides Beauv. and Artemisia capillaris Thunb. Our experiment included three BSC treatments (intact crust, disturbed crust, and bare soil) and five species trials (native E. poaeoides alone, E. poaeoides mixed with exotic S. glareosa, native A. capillaris alone, A. capillaris mixed with exotic S. glareosa, and S. glareosa alone). The results showed that cyanobacteria-dominated crusts can significantly reduce the cumulative percent germination of the exotic grass (P<0.001) and native plants (P<0.001). Maximum cumulative percent germinations of the exotic grass and two native plants were found in bare soil, and minimum in intact crusts. The interaction of crust treatment × species trials on shoot biomass of the two native plants was significant (P<0.05). These results indicate that the presence of BSCs on stabilized sand dunes may reduce the germination of the exotic and two native plants. The effect of reducing exotic and native plant seeds germination would maintain more diverse plant communities and contribute to the formation of clumped vegetation patterns. We conclude that BSCs act as a natural regulator for vegetation patterns and thus promote ecosystem stability and sustainability.

Why do people use exotic plants in their local medical systems? A systematic review based on Brazilian local communities.

PubMed

Medeiros, Patrícia Muniz de; Ferreira Júnior, Washington Soares; Ramos, Marcelo Alves; Silva, Taline Cristina da; Ladio, Ana Haydée; Albuquerque, Ulysses Paulino

2017-01-01

Efforts have been made to understand the processes that lead to the introduction of exotic species into local pharmacopoeias. Among those efforts, the diversification hypothesis predicts that exotic plants are introduced in local medical systems to amplify the repertoire of knowledge related to the treatment of diseases, filling blanks that were not occupied by native species. Based on such hypothesis, this study aimed to contribute to this discussion using the context of local Brazilian populations. We performed a systematic review of Brazilian studies up to 2011 involving medicinal plants, excluding those studies that presented a high risk of bias (because of sampling or plant identification problems). An analysis of similarities (ANOSIM) was conducted in different scales to test for differences in the repertoire of therapeutic indications treated using native and exotic species. We have found that although there is some overlap between native and exotic plants regarding their therapeutic indications and the body systems (BSs) that they treat, there are clear gaps present, that is, there are therapeutic indications and BSs treated that are exclusive to exotic species. This scenario enables the postulation of two alternative unfoldings of the diversification hypothesis, namely, (1) exotic species are initially introduced to fill gaps and undergo subsequent expansion of their use for medical purposes already addressed using native species and (2) exotic species are initially introduced to address problems already addressed using native species to diversify the repertoire of medicinal plants and to increase the resilience of medical systems. The reasons why exotic species may have a competitive advantage over the native ones, the implications of the introduction of exotic species for the resilience of medical systems, and the contexts in which autochthonous plants can gain strength to remain in pharmacopoeias are also discussed.

Effect of biological soil crusts on seed germination and growth of an exotic and two native plant species in an arid ecosystem

PubMed Central

Li, Xinrong; Hui, Rong

2017-01-01

Biological soil crusts (BSCs) can improve the stability and health of native plant communities in arid ecosystems. However, it is unknown whether BSCs can also inhibit invasions of exotic vascular plants on stabilized reclaimed sand dunes. To answer this question, we conducted a greenhouse experiment to test the effects of cyanobacteria-dominated BSCs on 1) seed germination and biomass of an exotic grass (Stipa glareosa P. Smirn.), and 2) individual biomass of the exotic S. glareosa growing with two native plants, Eragrostis poaeoides Beauv. and Artemisia capillaris Thunb. Our experiment included three BSC treatments (intact crust, disturbed crust, and bare soil) and five species trials (native E. poaeoides alone, E. poaeoides mixed with exotic S. glareosa, native A. capillaris alone, A. capillaris mixed with exotic S. glareosa, and S. glareosa alone). The results showed that cyanobacteria-dominated crusts can significantly reduce the cumulative percent germination of the exotic grass (P<0.001) and native plants (P<0.001). Maximum cumulative percent germinations of the exotic grass and two native plants were found in bare soil, and minimum in intact crusts. The interaction of crust treatment × species trials on shoot biomass of the two native plants was significant (P<0.05). These results indicate that the presence of BSCs on stabilized sand dunes may reduce the germination of the exotic and two native plants. The effect of reducing exotic and native plant seeds germination would maintain more diverse plant communities and contribute to the formation of clumped vegetation patterns. We conclude that BSCs act as a natural regulator for vegetation patterns and thus promote ecosystem stability and sustainability. PMID:28977018

9 CFR 352.7 - Marking inspected products.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., exotic animal tongues, and exotic animal hearts. EC11SE91.031 (2) For application to exotic animal calf... used on shipping containers, bond labels, artificial casings, and other articles with the approval of...

9 CFR 352.7 - Marking inspected products.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., exotic animal tongues, and exotic animal hearts. EC11SE91.031 (2) For application to exotic animal calf... used on shipping containers, bond labels, artificial casings, and other articles with the approval of...

Potential Habitats for Exotic Life Within the Life Supporting Zone

NASA Astrophysics Data System (ADS)

Leitner, Johannes J.; Firneis, Maria G.; Hitzenberger, Regina

2010-05-01

Questions like "Are we alone in the universe?", "How unique is Earth as a planet?" or "How unique is water-based life in the universe?" still are nowhere near of being answered. In recent years, discussions on these topics are more and more influenced by questions whether water is really the only possible solvent, or which conditions are necessary for life to evolve in planetary habitats. A change in our present geocentric mindset on the existence of life is required, in order to address these new questions [see also 1]. In May 2009 a new research platform at the University of Vienna was initiated in order to contribute to the solution of these questions. One task is to find essential biomarkers relevant to the problem of the detection of exotic life. In this context exotic life means: life, which is not necessarily based on a double bond between carbon and oxygen (C=O) and not on water as the only possible solvent. At present little is known about metabolistic systems, which are not based on C=O or on metabolisms which are operative in alternative solvents and a high effort of future laboratory work is necessary to open this window for looking for exotic life. To address the whole spectrum of life the concept of a general life supporting zone is introduced in order to extend the classical habitable zone (which is based on liquid water on a planetary surface, [2]). The life supporting zone of a planetary system is composed of different single "habitable zones" for the liquid phases of specific solvents and composites between water and other solvents. Besides exoplanetary systems which seem to be the most promising place for exotic life in our present understanding, some potential places could also exist within our Solar System and habitats like the subsurface of Enceladus, liquid ethane/methane lakes on Titan or habitable niches in the Venus atmosphere will also be taken into account. A preliminary list of appropriate solvents and their abundances in the Solar System and beyond have been compiled. Dynamical investigations (related to the interior of superearths), but also heat transport regimes and potential cycles with exotic solvents as well as tidal heating processes and their influence on the thermal regime of the planets will help to define the regions of potential exotic life more precisely. Atmospheric and subsurface cycles which can take place in such habitats as well as cloud and droplet formation with and without cloud nuclei cores will further extend our knowledge on mechanisms relevant for the stability of these systems. Finally the question of suitable biomarkers, which can enable the observation of exotic habitats and their potential life forms will be considered in the research platform. In this context a special topic is also the bandwidth of photosynthesis: how is the influence of different atmospheric gases and what are the environment conditions for the chemical reactions of photosynthesis? First preliminary results for the life supporting zones of selected planetary systems will be presented. References: [1] NRC (National Research Council)(2007) The Limits of Organic Life in Planetary Systems, National Academies Press, Washington, DC 20001, ISBN 978-0-309-10484-5. [2] Kasting, J.F., Whitmore D.P. and Reynolds R.T. (1993) Icarus, 101, 109-128.

Linking invasive exotic vertebrates and their ecosystem impacts in Tierra del Fuego to test theory and determine action

NASA Astrophysics Data System (ADS)

Valenzuela, Alejandro E. J.; Anderson, Christopher B.; Fasola, Laura; Cabello, José L.

2014-01-01

Understanding processes and impacts of biological invasions is fundamental for ecology and management. Recent reviews summarized the mechanisms by which invasive species alter entire ecosystems, but quantitative assessments of these mechanisms are lacking for actual assemblages to determine their relative importance, frequency and patterns. We updated information on introduced vertebrates in the Tierra del Fuego Archipelago (TDF) via an exhaustive literature review and new data to evaluate ecosystem impact mechanisms and provide management recommendations. To date, 24 exotic vertebrates have naturalized in TDF, outnumbering natives nearly 2:1, with the North American beaver (Castor canadensis) and muskrat (Ondatra zibethica) being the most widely distributed species and also impacting the ecosystem through the greatest number of mechanisms. Introduced vertebrates occupied most parts of the archipelago with human-inhabited islands having greater taxa richness. All exotics potentially altered ecosystems by one or more mechanisms: 100% food webs, 92% invasional meltdown, 42% habitat modification, 38% disease or parasite transmission, 21% soil property and disturbance regime changes. Impact to habitat structure was the main clustering criterion for this assemblage. Within the species that physically alter habitats, we found two sub-groups: 1) large herbivores and 2) "others" including beavers and muskrats. Species that did not alter habitat were divided further into those with predatory trophic effects (carnivorous mammals and trout, sub-group 4) and the rest with assorted impacts (sub-group 3). By establishing high quality information on archipelago-wide assemblage, distribution, impacts and mechanisms for exotic vertebrates, we recommend, based on ecological criteria, prioritizing the management of sub-group 2. A secondary priority might be given to the carnivores in sub-group 4, while species in sub-groups 1 and 3 are less urgent. As the first systematic survey of introduced fauna on an archipelago-scale, we identified knowledge gaps, such as population abundance and dynamics for specific species, which are needed to orient future work, but the notable progress made to date is highlighted.

A new perspective on trait differences between native and invasive exotic plants.

PubMed

Leffler, A Joshua; James, Jeremy J; Monaco, Thomas A; Sheley, Roger L

2014-02-01

Functional differences between native and exotic species potentially constitute one factor responsible for plant invasion. Differences in trait values between native and exotic invasive species, however, should not be considered fixed and may depend on the context of the comparison. Furthermore, the magnitude of difference between native and exotic species necessary to trigger invasion is unknown. We propose a criterion that differences in trait values between a native and exotic invasive species must be greater than differences between co-occurring natives for this difference to be ecologically meaningful and a contributing factor to plant invasion. We used a meta-analysis to quantify the difference between native and exotic invasive species for various traits examined in previous studies and compared this value to differences among native species reported in the same studies. The effect size between native and exotic invasive species was similar to the effect size between co-occurring natives except for studies conducted in the field; in most instances, our criterion was not met although overall differences between native and exotic invasive species were slightly larger than differences between natives. Consequently, trait differences may be important in certain contexts, but other mechanisms of invasion are likely more important in most cases. We suggest that using trait values as predictors of invasion will be challenging.

Exotic Dance in Baltimore: From Entry to STI/HIV Risk.

PubMed

Lilleston, Pamela S; Reuben, Jacqueline; Sherman, Susan G

2015-01-01

Research has documented health risks associated with sex work, but few U.S. studies have focused on the exotic dance industry. We undertook this study to describe the factors that influenced women's entry into exotic dance and explored the relation of these forces to their subsequent sexually transmitted infection (STI)/HIV risk trajectory. Qualitative interviews (N = 25) were conducted with female exotic dancers from June through August 2009. Data were analyzed through Atlas-ti using an inductive approach. Economic vulnerability was the primary force behind women's initiation into the profession. Drug use, physical abuse, and enjoyment of dancing were often concurrent with economic need and provided a further push toward exotic dance. Social networks facilitated entry by normalizing the profession and presenting it as a solution to financial hardship. Characteristics of exotic dance clubs, such as immediate hire and daily pay, attracted women in a state of financial vulnerability. Women's motivations for dancing, including economic vulnerability and drug use practices, shaped their STI/HIV risk once immersed in the club environment, with social networks often facilitating sexual risk behavior. Understanding the factors that drive women to exotic dance and influence risk behavior in the club may assist in the development of targeted harm reduction interventions for exotic dancers.

Exotic Dance in Baltimore: From Entry to STI/HIV Risk

PubMed Central

Reuben, Jacqueline; Sherman, Susan G.

2015-01-01

Research has documented health risks associated with sex work, but few U.S. studies have focused on the exotic dance industry. We undertook to describe the factors that influenced women's entry into exotic dance and explored the relation of these forces to their subsequent Sexually Transmitted Infection (STI)/HIV risk trajectory. Qualitative interviews (N=25) were conducted with female exotic dancers from June through August, 2009. Data were analyzed through Atlas-ti using an inductive approach. Economic vulnerability was the primary force behind women's initiation into the profession. Drug use, physical abuse, and enjoyment of dancing were often concurrent with economic need and provided a further push toward exotic dance. Social networks facilitated entry by normalizing the profession and presenting it as a solution to financial hardship. Characteristics of exotic dance clubs, such as immediate hire and daily pay, attracted women in a state of financial vulnerability. Women's motivations for dancing, including economic vulnerability and drug use practices, shaped their STI/HIV risk once immersed in the club environment, with social networks often facilitating sexual risk behavior. Understanding the factors that drive women to exotic dance and influence risk behavior in the club may assist in the development of targeted harm reduction interventions for exotic dancers. PMID:25807063

Population Dynamics and Temperature-Dependent Development of Chrysomphalus aonidum (L.) to Aid Sustainable Pest Management Decisions.

PubMed

Campolo, O; Malacrinò, A; Laudani, F; Maione, V; Zappalà, L; Palmeri, V

2014-10-01

The increasing worldwide trades progressively led to decreased impact of natural barriers on wild species movement. The exotic scale Chrysomphalus aonidum (L.) (Hemiptera: Diaspididae), recently reported on citrus in southern Italy, may represent a new threat to Mediterranean citriculture. We studied C. aonidum population dynamics under field conditions and documented its development under various temperatures. To enable describing temperature-dependent development through the use of linear and non-linear models, low temperature thresholds and thermal constants for each developmental stage were estimated. Chrysomphalus aonidum was able to perform four generations on green parts (leaves, sprouts) of citrus trees and three on fruits. In addition, an overall higher population density was observed on samples collected in the southern part of the tree canopy. Temperature had a significant effect on the developmental rate; female needed 625 degree days (DD) to complete its development, while male needed 833 DD. The low threshold temperatures, together with data from population dynamics, demonstrated that C. aonidum is able to overwinter as second instar and as an adult. The results obtained, validated by those collected in the field, revealed few differences between predicted and observed dates of first occurrence of each C. aonidum instar in citrus orchards. Data on C. aonidum phenology and the definition of the thermal parameters (lower and upper threshold temperatures, optimum temperature, and the thermal constant) by non-linear models could allow the estimation of the occurrence in the field of each life stage and would be helpful in developing effective integrated control strategies.

The mass formula for an exotic BTZ black hole

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

Zhang, Baocheng, E-mail: zhangbc.zhang@yahoo.com

2016-04-15

An exotic Bañados–Teitelboim–Zanelli (BTZ) black hole has an angular momentum larger than its mass in three dimension (3D), which suggests the possibility that cosmic censorship could be violated if angular momentum is extracted by the Penrose process. In this paper, we propose a mass formula for the exotic BTZ black hole and show no violation of weak cosmic censorship in the gedanken process above by understanding properly its mass formula. Unlike the other black holes, the total energy of the exotic BTZ black hole is represented by the angular momentum instead of the mass, which supports a basic point ofmore » view that the same geometry should be determined by the same energy in 3D general relativity whose equation of motion can be given either by normal 3D Einstein gravity or by exotic 3D Einstein gravity. However, only the mass of the exotic black hole is related to the thermodynamics and other forms of energy are “dumb”, which is consistent with the earlier thermodynamic analysis about exotic black holes.« less

Sustainability of the Lake Superior fish community: Interactions in a food web context

USGS Publications Warehouse

Kitchell, James F.; Cox, Sean P.; Harvey, Chris J.; Johnson, Timothy B.; Mason, Doran M.; Schoen, Kurt K.; Aydin, Kerim; Bronte, Charles; Ebener, Mark; Hansen, Michael; Hoff, Michael; Schram, Steve; Schreiner, Don; Walters, Carl J.

2000-01-01

The restoration and rehabilitation of the native fish communities is a long-term goal for the Laurentian Great Lakes. In Lake Superior, the ongoing restoration of the native lake trout populations is now regarded as one of the major success stories in fisheries management. However, populations of the deepwater morphotype (siscowet lake trout) have increased much more substantially than those of the nearshore morphotype (lean lake trout), and the ecosystem now contains an assemblage of exotic species such as sea lamprey, rainbow smelt, and Pacific salmon (chinook, coho, and steelhead). Those species play an important role in defining the constraints and opportunities for ecosystem management. We combined an equilibrium mass balance model (Ecopath) with a dynamic food web model (Ecosim) to evaluate the ecological consequences of future alternative management strategies and the interaction of two different sets of life history characteristics for fishes at the top of the food web. Relatively rapid turnover rates occur among the exotic forage fish, rainbow smelt, and its primary predators, exotic Pacific salmonids. Slower turnover rates occur among the native lake trout and burbot and their primary prey—lake herring, smelt, deepwater cisco, and sculpins. The abundance of forage fish is a key constraint for all salmonids in Lake Superior. Smelt and Mysis play a prominent role in sustaining the current trophic structure. Competition between the native lake trout and the exotic salmonids is asymmetric. Reductions in the salmon population yield only a modest benefit for the stocks of lake trout, whereas increased fishing of lake trout produces substantial potential increases in the yields of Pacific salmon to recreational fisheries. The deepwater or siscowet morphotype of lake trout has become very abundant. Although it plays a major role in the structure of the food web it offers little potential for the restoration of a valuable commercial or recreational fishery. Even if a combination of strong management actions is implemented, the populations of lean (nearshore) lake trout cannot be restored to pre-fishery and pre-lamprey levels. Thus, management strategy must accept the ecological constraints due in part to the presence of exotics and choose alternatives that sustain public interest in the resources while continuing the gradual progress toward restoration.

Antideuterons in cosmic rays: sources and discovery potential

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

Herms, Johannes; Ibarra, Alejandro; Vittino, Andrea

Antibaryons are produced in our Galaxy in collisions of high energy cosmic rays with the interstellar medium and in old supernova remnants, and possibly, in exotic sources such as primordial black hole evaporation or dark matter annihilations and decays. The search for signals from exotic sources in antiproton data is hampered by large backgrounds from spallation which, within theoretical errors, can solely account for the current data. Due to the higher energy threshold for antideuteron production, which translates into a suppression of the low energy flux from spallations, antideuteron searches have been proposed as a probe for exotic sources. Wemore » perform in this paper a comprehensive analysis of the antideuteron fluxes at the Earth expected from known and hypothetical sources in our Galaxy, and we calculate their maximal values consistent with current antiproton data from AMS-02. We find that supernova remnants generate a negligible flux, whereas primordial black hole evaporation and dark matter annihilations or decays may dominate the total flux at low energies. On the other hand, we find that the (detection of cosmic antideuterons) would require, for the scenarios studied in this paper and assuming optimistic values of the coalescence momentum and solar modulation, an increase of the experimental sensitivity compared to ongoing and planned instruments by at least a factor of 2. Finally, we briefly comment on the prospects for antihelium-3 detection.« less

Medicinal wild plant knowledge and gathering patterns in a Mapuche community from North-western Patagonia.

PubMed

Estomba, Diego; Ladio, Ana; Lozada, Mariana

2006-01-03

Medicinal plant use has persisted as a long standing tradition in the Mapuche communities of Southern Argentina and Chile. An ethnobotanical survey was conducted in the rural Curruhuinca community located near the mountain city of San Martin de los Andes, Argentina. Semi-structured interviews were carried out on 22 families in order to examine the present use of medicinal plants and their reputed therapeutic effects. Ecological variables, such as distance to the gathering site and biogeographical origin were also analyzed. Our results showed that the Curruhuinca dwellers cited 89 plant species for medicinal purposes, both of native and exotic origin. They know about 47 native plants, of which they use 40, and they know of 42 exotic medicinal plants of which they use 34. A differential pattern was observed given that only native species, relevant for the traditional Mapuche medicine, were collected at more distant gathering sites. The interviewees mentioned 268 plant usages. Those most frequently reported had therapeutic value for treating digestive ailments (33%), as analgesic/anti-inflammatory (25%) and antitusive (13%). Native species were mainly cited as analgesics, and for gynecological, urinary and "cultural syndrome" effects, whereas exotic species were mainly cited for digestive ailments. The total number of medicinal plants known and used by the interviewees was positively correlated with people's age, indicating that this ancient knowledge tends to disappear in the younger generations.

Phenomenology of U(1)F extension of inert-doublet model with exotic scalars and leptons

NASA Astrophysics Data System (ADS)

Dhargyal, Lobsang

2018-02-01

In this work we will extend the inert-doublet model (IDM) by adding a new U(1)F gauge symmetry to it, under which, a Z2 even scalar (φ 2) and Z2 odd right handed component of two exotic charged leptons (F_{eR}, F_{μ R}), are charged. We also add one Z2 even real scalar (φ 1) and one complex scalar (φ ), three neutral Majorana right handed fermions (N1, N2, N3), two left handed components of the exotic charged leptons (F_{eL}, F_{μ L}) as well as F_{τ } are all odd under the Z2, all of which are not charged under the U(1)F. With these new particles added to the IDM, we have a model which can give two scalar DM candidates, together they can explain the present DM relic density as well as the muon (g-2) anomaly simultaneously. Also in this model the neutrino masses are generated at one loop level. One of the most peculiar feature of this model is that non-trivial solution to the axial gauge anomaly free conditions lead to the prediction of a stable very heavy partner to the electron (Fe), whose present collider limit (13 TeV LHC) on its mass should be around m_{Fe} ≥ few TeV.

Physics of Unstable Nuclei

NASA Astrophysics Data System (ADS)

Khoa, Dao Tien; Egelhof, Peter; Gales, Sydney; Giai, Nguyen Van; Motobayashi, Tohru

2008-04-01

Studies at the RIKEN RI beam factory / T. Motobayashi -- Dilute nuclear states / M. Freer -- Studies of exotic systems using transfer reactions at GANIL / D. Beaumel et al. -- First results from the Magnex large-acceptance spectrometer / A. Cunsolo et al. -- The ICHOR project and spin-isospin physics with unstable beams / H. Sakai -- Structure and low-lying states of the [symbol]He exotic nucleus via direct reactions on proton / V. Lapoux et al. -- Shell gap below [symbol]Sn based on the excited states in [symbol]Cd and [symbol]In / M. Górska -- Heavy neutron-rich nuclei produced in the fragmentation of a [symbol]Pb beam / Zs. Podolyák et al. -- Breakup and incomplete fusion in reactions of weakly-bound nuclei / D.J. Hinde et al. -- Excited states of [symbol]B and [symbol]He and their cluster aspect / Y. Kanada-En'yo et al. -- Nuclear reactions with weakly-bound systems: the treatment of the continuum / C. H. Dasso, A. Vitturi -- Dynamic evolution of three-body decaying resonances / A. S. Jensen et al. -- Prerainbow oscillations in [symbol]He scattering from the Hoyle state of [symbol]C and alpha particle condensation / S. Ohkubo, Y. Hirabayashi -- Angular dispersion behavior in heavy ion elastic scattering / Q. Wang et al. -- Microscopic optical potential in relativistic approach / Z.Yu. Ma et al. -- Exotic nuclei studied in direct reactions at low momentum transfer - recent results and future perspectives at fair / P. Egelhof -- Isotopic temperatures and symmetry energy in spectator fragmentation / M. De Napoli et al. -- Multi-channel algebraic scattering theory and the structure of exotic compound nuclei / K. Amos et al. -- Results for the first feasibility study for the EXL project at the experimental storage ring at GSI / N. Kalantar-Nayestanaki et al. -- Coulomb excitation of ISOLDE neutron-rich beams along the Z = 28 chain / P. Van Duppen -- The gamma decay of the pygmy resonance far from stability and the GDR at finite temperature / G. Benzoni et al. -- Thermal pairing in nuclei / N. D. Dang -- Molecular-orbital and di-nuclei states in Ne and F isotopes / M. Kimura -- Low-momentum interactions for nuclei / A. Schwenk -- Nonrelativistic nuclear energy functionals including the tensor force / G. Colo et al. -- New aspects on dynamics in nuclei described by covariant density functional theory / P. Ring, D. Pena -- Theoretical studies on ground-state properties of superheavy nuclei / Z. Z. Ren et al. -- New results in the study of superfluid nuclei: many-body effects, spectroscopic factors / P. F. Bortignon et al. -- New Effective nucleon-nucleon interaction for the mean-field approximation / V. K. Au et al. -- Linear response calculations with the time-dependent Skyrme density functional / T. Nakatsukasa et al. -- Dissipative dynamics with exotic beams / M. Di Toro et al. -- Exploring the symmetry energy of asymmetric nuclear matter with heavy ion reactions / M. B. Tsang -- Invariant mass spectroscopy of halo nuclei / T. Nakamura et al. -- Core [symbol] structures in [symbol]C, [symbol]C and [symbol]C up to high excitation energies / H. G. Bohlen et al. -- Light neutron-rich nuclei studied by alpha-induced reactions / S. Shimoura -- Fusion and direct reactions around the Coulomb barrier for the system [symbol]He + [symbol]Zn / V. Scuderi et al. -- Analyzing power measurement for proton elastic scattering on [symbol]He / S. Sakaguchi et al. -- Knockout reaction spectroscopy of exotic nuclei / J. A. Tostevin -- Exotic nuclei, quantum phase transitions, and the evolution of structure / R. F. Casten -- Structure of exotic nuclei in the medium mass region / T. Otsuka -- Pairing correlations in halo nuclei / H. Sagawa, K. Hagino -- Experimental approach to high-temperature Stellar reactions with low-energy RI beams / S. Kubono et al. -- Transition to quark matter in neutron stars / G. X. Peng et al. -- Research at VATLY: main themes and recent results / P. N. Diep et al. -- Study of the astrophysical reaction [symbol]C([symbol], n)[symbol]O by the transfer reaction [symbol]C([symbol]Li, t)[symbol]O / F. Hammache et al. -- SPIRAL2 at GANIL: a world of leading ISOL facility for the physics of exotic nuclei / S. Gales -- Magnetic properties of light neutron-rich nuclei and shell evolution / T. Suzuki, T. Otsuka -- Multiple scattering effects in elastic and quasi free proton scattering from halo nuclei / R. Crespo et al. -- The dipole response of neutron halos and skins / T. Aumann -- Giant and pygmy resonances within axially-symmetric-deformed QRPA with the Gogny force / S. Péru, H. Goutte -- Soft K[symbol] = O+ modes unique to deformed neutron-rich unstable nuclei / K. Yoshida et al. -- Synthesis, decay properties, and identification of superheavy nuclei produced in [symbol]Ca-induced reactions / Yu. Ts. Oganessian et al. -- Highlights of the Brazilian RIB facility and its first results and hindrance of fusion cross section induced by [symbol]He / P. R. S. Gomes et al. -- Search for long fission times of super-heavy elements with Z = 114 / M. Morjean et al. -- Microscopic dynamics of shape coexistence phenomena around [symbol]Se and [symbol]Kr / N. Hinohara et al. -- [symbol]-cluster states and 4[symbol]-particle condensation in [symbol]O / Y. Funaki et al. -- Evolution of the N = 28 shell closure far from stability / O. Sorlin et al. -- Continuum QRPA approach and the surface di-neutron modes in nuclei near the neutron drip-line / M. Matsuo et al. -- Deformed relativistic Hartree-Bogoliubov model for exotic nuclei / S. G. Zhou et al. -- Two- and three-body correlations in three-body resonances and continuum states / K. Katō, K. Ikeda -- Pion- and Rho-Meson effects in relativistic Hartree-Fock and RPA / N. V. Giai et al. -- Study of the structure of neutron rich nuclei by using [symbol]-delayed neutron and gamma emission method / Y. Ye et al. -- Production of secondary radioactive [symbol] Na beam for the study of [symbol]Na([symbol], p)[symbol]Mg stellar reaction / D. N. Binh et al. -- Asymmetric nuclear matter properties within the Brueckner theory / W. Zuo et al. -- Study of giant dipole resonance in continuum relativistic random phase approximation / D. Yang et al. -- Chiral bands for quasi-proton and quasi-neutron coupling with a triaxial rotor / B. Qi et al. -- Continuum properties of the Hartree-Fock mean field with finite-range interactions / H. S. Than et al. -- A study of pairing interaction in a separable form / Y. Tian et al. -- Microscopic study of the inelastic [symbol]+[symbol]C scattering / D. C. Cuong, D. T. Khoa -- Probing the high density behavior of the symmetry energy / F. Zhang et al. -- Microscopic calculations based on a Skyrme functional plus the pairing contribution / J. Li et al. -- In-medium cross sections in Dirac-Brueckner-Hartree-Fock approach / L. Peiyan et al. -- The effect of the tensor force on single-particle states and on the isotope shift / W. Zou et al. -- [symbol]Ne excited states two-proton decay / M. De Napoli et al. -- The isomeric ratio and angular momentum of fragment [symbol]Xe in photofission of heavy nuclei / T. D. Thiep et al. -- Search for correlated two-nucleon systems in [symbol]Li and [symbol]He nuclei via one-nucleon exchange reaction / N. T. Khai et al. -- Summary talk of ISPUN07 / N. Alamanos.

Housing is positively associated with invasive exotic plant species richness in New England, USA.

PubMed

Gavier-Pizarro, Gregorio I; Radeloff, Volker C; Stewart, Susan I; Huebner, Cynthia D; Keuler, Nicholas S

2010-10-01

Understanding the factors related to invasive exotic species distributions at broad spatial scales has important theoretical and management implications, because biological invasions are detrimental to many ecosystem functions and processes. Housing development facilitates invasions by disturbing land cover, introducing nonnative landscaping plants, and facilitating dispersal of propagules along roads. To evaluate relationships between housing and the distribution of invasive exotic plants, we asked (1) how strongly is housing associated with the spatial distribution of invasive exotic plants compared to other anthropogenic and environmental factors; (2) what type of housing pattern is related to the richness of invasive exotic plants; and (3) do invasive plants represent ecological traits associated with specific housing patterns? Using two types of regression analysis (best subset analysis and hierarchical partitioning analysis), we found that invasive exotic plant richness was equally or more strongly related to housing variables than to other human (e.g., mean income and roads) and environmental (e.g., topography and forest cover) variables at the county level across New England. Richness of invasive exotic plants was positively related to area of wildland-urban interface (WUI), low-density residential areas, change in number of housing units between 1940 and 2000, mean income, plant productivity (NDVI), and altitudinal range and rainfall; it was negatively related to forest area and connectivity. Plant life history traits were not strongly related to housing patterns. We expect the number of invasive exotic plants to increase as a result of future housing growth and suggest that housing development be considered a primary factor in plans to manage and monitor invasive exotic plant species.

Effects of exotic grasses on soil seed banks in Southeastern Arizona grasslands

USGS Publications Warehouse

McLaughlin, S.P.; Bowers, Janice E.

2007-01-01

At the Appleton-Whittell Research Ranch, an ungrazed grassland preserve in southeastern Arizona, soil seed banks were sampled in June, August, and October 2002 and June 2003. Wildfire had previously burned 90% of the research ranch in May 2002. Seed density and species richness in burned native grassland (2 plots) were compared to those in burned exotic grassland (2 plots). Averaged over 4 sample dates, seed densities were as follows: burned native grassland, 591 ?? 243.1 seeds??m-2 and 784 ?? 334.9 seeds??m-2; burned exotic grassland, 501 ?? 198.9 seeds??m-2 and 196 ?? 123.8 seeds??m-2. Species richness in the seed bank, also averaged over 4 sample dates, was as follows: burned native grassland, 16.3 ?? 1.7 species??m -2 and 19.5 ?? 1.0 species??m-2; burned exotic grassland, 12.0 ?? 3.4 species??m-2 and 11.06 ?? 2.5 species??m-2. The seed bank of burned exotic grassland contained significantly fewer seeds and species than that of burned native grassland. In addition, the seed bank in burned exotic grassland comprised mainly exotic grasses, whereas annual and perennial herbs, most of them native, dominated the seed bank of burned native grassland. Of the 50 species detected in soil samples, only 20 had a persistent seed bank, and only 1 of these was a native perennial bunchgrass. The preponderance of transient species means that eradication of exotic grasses must be followed by reseeding of native grasses and herbs, perhaps repeatedly, if native grassland is to replace exotic grassland.

String-inspired special grand unification

NASA Astrophysics Data System (ADS)

Yamatsu, Naoki

2017-10-01

We discuss a grand unified theory (GUT) based on an SO(32) GUT gauge group broken to its subgroups including a special subgroup. In the SO(32) GUT on the six-dimensional (6D) orbifold space M^4× T^2/\\mathbb{Z}_2, one generation of the standard model fermions can be embedded into a 6D bulk Weyl fermion in the SO(32) vector representation. We show that for a three-generation model, all the 6D and 4D gauge anomalies in the bulk and on the fixed points are canceled out without exotic chiral fermions at low energies.

Firewood Alert

Treesearch

USDA Forest Service, Northeastern Area State and Private Forestry; PA Department of Conservation and Natural Resources; Pennsylvania Department of Agriculture

2006-01-01

Help stop the movement of exotic pests. Don't move Firewood! Exotic wood borers like emerald ash borer, Asian Long-horned beetle and Sirex wood wasp threaten Pennsylvania's forestland. Exotic wood boring insects can become established when infested firewood is transported to new areas.

Provenance of KREEP and the exotic component - Elemental and isotopic studies of grain size fractions in lunar soils

NASA Technical Reports Server (NTRS)

Evensen, N. M.; Murthy, V. R.; Coscio, M. R., Jr.

1974-01-01

Sieve fraction analyses of lunar soils reveal the presence of a fine-grained exotic component enriched in K, Rb, Sr, Ba, and in radiogenic Sr in all soils. The probable source of this exotic component is the areas of high-surficial radioactivity observed by orbital gamma ray spectrometry, such as those at Fra Mauro and Archimedes. If the exotic component is fine-grained KREEP, the origin and distribution of KREEP fragments in the soils are identified. It is suggested that the exotic component represents trace element enriched material located at some depth in the Imbrium area which was surficially deposited during Imbrium excavation.

Vulnerability of oak-dominated forests in West Virginia to invasive exotic plants: temporal and spatial patterns of nine exotic species using herbarium records and land classification data

Treesearch

Cynthia D. Huebner

2003-01-01

Are oak-dominated forests immune to invasive exotic plants? Herbarium and land classification data were used to evaluate the extent of spread of nine invasive exotic plants and to relate their distributions to remotely-sensed land use types in West Virginia. Collector-defined habitats indicated that the most common habitat was roadsides, but seven of the nine species...

Soil characteristics and plant exotic species invasions in the Grand Staircase-Escalante National Monument, Utah, USA

USGS Publications Warehouse

Bashkin, Michael A.; Stohlgren, Thomas J.; Otsuki, Yuka; Lee, Michelle; Evangelista, Paul H; Belnap, Jayne

2003-01-01

The Grand Staircase - Escalante National Monument (GSENM) contains a rich diversity of native plant communities. However, many exotic plant species have become established, potentially threatening native plant diversity. We sought to quantify patterns of native and exotic plant species and cryptobiotic crusts (mats of lichens, algae, and mosses on the soil surface), and to examine soil characteristics that may indicate or predict exotic species establishment and success. We established 97 modified-Whittaker vegetation plots in 11 vegetation types over a 29,000 ha area in the Monument. Canonical correspondence analysis (CCA) and multiple linear regressions were used to quantify relationships between soil characteristics and associated native and exotic plant species richness and cover. CCA showed that exotic species richness was significantly (P<0.05) associated with soil P (r=0.84), percentage bare ground (r=0.71), and elevation (r=0.67). Soil characteristics alone were able to predict 41 and 46% of the variation in exotic species richness and cover, respectively. In general, exotic species invasions tend to occur in fertile soils relatively high in C, N and P. These areas are represented by rare mesic high-elevation habitats that are rich in native plant diversity. This suggests that management should focus on the protection of the rare but important vegetation types with fertile soils.

Local dominance of exotic plants declines with residence time: a role for plant–soil feedback?

PubMed Central

Speek, Tanja A.A.; Schaminée, Joop H.J.; Stam, Jeltje M.; Lotz, Lambertus A.P.; Ozinga, Wim A.; van der Putten, Wim H.

2015-01-01

Recent studies have shown that introduced exotic plant species may be released from their native soil-borne pathogens, but that they become exposed to increased soil pathogen activity in the new range when time since introduction increases. Other studies have shown that introduced exotic plant species become less dominant when time since introduction increases, and that plant abundance may be controlled by soil-borne pathogens; however, no study yet has tested whether these soil effects might explain the decline in dominance of exotic plant species following their initial invasiveness. Here we determine plant–soil feedback of 20 plant species that have been introduced into The Netherlands. We tested the hypotheses that (i) exotic plant species with a longer residence time have a more negative soil feedback and (ii) greater local dominance of the introduced exotic plant species correlates with less negative, or more positive, plant–soil feedback. Although the local dominance of exotic plant species decreased with time since introduction, there was no relationship of local dominance with plant–soil feedback. Plant–soil feedback also did not become more negative with increasing time since introduction. We discuss why our results may deviate from some earlier published studies and why plant–soil feedback may not in all cases, or not in all comparisons, explain patterns of local dominance of introduced exotic plant species. PMID:25770013

Including the introduction of exotic species in life cycle impact assessment: the case of inland shipping.

PubMed

Hanafiah, Marlia M; Leuven, Rob S E W; Sommerwerk, Nike; Tockner, Klement; Huijbregts, Mark A J

2013-12-17

While the ecological impact of anthropogenically introduced exotic species is considered a major threat for biodiversity and ecosystems functioning, it is generally not accounted for in the environmental life cycle assessment (LCA) of products. In this article, we propose a framework that includes exotic species introduction in an LCA context. We derived characterization factors for exotic fish species introduction related to the transport of goods across the Rhine-Main-Danube canal. These characterization factors are expressed as the potentially disappeared fraction (PDF) of native freshwater fish species in the rivers Rhine and Danube integrated over space and time per amount of goods transported (PDF·m(3)·yr·kg(-1)). Furthermore, we quantified the relative importance of exotic fish species introduction compared to other anthropogenic stressors in the freshwater environment (i.e., eutrophication, ecotoxicity, greenhouse gases, and water consumption) for transport of goods through the Rhine-Main-Danube waterway. We found that the introduction of exotic fish species contributed to 70-85% of the total freshwater ecosystem impact, depending on the distance that goods were transported. Our analysis showed that it is relevant and feasible to include the introduction of exotic species in an LCA framework. The proposed framework can be further extended by including the impacts of other exotic species groups, types of water bodies and pathways for introduction.

Grassland birds wintering at U.S. Navy facilities in southern Texas

USGS Publications Warehouse

Woodin, Marc C.; Skoruppa, Mary Kay; Bryan, Pearce D.; Ruddy, Amanda J.; Hickman, Graham C.

2010-01-01

Grassland birds have undergone widespread decline throughout North America during the past several decades. Causes of this decline include habitat loss and fragmentation because of conversion of grasslands to cropland, afforestation in the East, brush and shrub invasion in the Southwest and western United States, and planting of exotic grass species to enhance forage production. A large number of exotic plant species, including grasses, have been introduced in North America, but most research on the effects of these invasions on birds has been limited to breeding birds, primarily those in northern latitudes. Research on the effects of exotic grasses on birds in winter has been extremely limited.This is the first study in southern Texas to examine and compare winter bird responses to native and exotic grasslands. This study was conducted during a period of six years (2003–2009) on United States Navy facilities in southern Texas including Naval Air Station–Corpus Christi, Naval Air Station–Kingsville, Naval Auxiliary Landing Field Waldron, Naval Auxiliary Landing Field Orange Grove, and Escondido Ranch, all of which contained examples of native grasslands, exotic grasslands, or both. Data from native and exotic grasslands were collected and compared for bird abundance and diversity; ground cover, vegetation density, and floristic diversity; bird and vegetation relationships; diversity of insects and arachnids; and seed abundance and diversity. Effects of management treatments in exotic grasslands were evaluated by comparing numbers and diversity of birds and small mammals in mowed, burned, and control areas.To determine bird abundance and bird species richness, birds were surveyed monthly (December–February) during the winters of 2003–2008 in transects (100 meter × 20 meter) located in native and exotic grasslands distributed at all five U.S. Navy facilities. To compare vegetation in native and exotic grasslands, vegetation characteristics were measured during 2003–2008 in the same transects used for bird surveys and included five measures of ground cover, plus estimates of plant species richness, vegetation density (visual obstruction) at two different heights, and shrub numbers. These data, plus seasonal rainfall, were then used to evaluate components of variation in native and exotic grasslands. Relations between total bird numbers and bird species richness with environmental variation in native and exotic grasslands were compared. To compare diversity of arthropods in native and exotic grasslands, insects and arachnids were collected using three different methodologies (standardized sweep-net, random sweep-net, and pitfall traps) during four seasons, (2005–2006), at Naval Air Station–Corpus Christi, Naval Auxiliary Landing Field Waldron, and Naval Air Station–Kingsville. To compare seed abundance and diversity between native and exotic grasslands, seeds were collected for two winters (2004–2006) at Naval Air Station–Corpus Christi and Naval Air Station–Kingsville. To evaluate effects of management on grassland vertebrates, abundance and diversity of birds and small mammals were estimated and compared in exotic grasses subjected to mowing, burning, or no active management (control) for one full year (2008–2009).Observations were made of 1,044 birds of 30 species in grassland transects during five winters. The Savannah Sparrow (Passerculus sandwichensis) was the most common bird, which, with 644 detections, accounted for 63 percent of all individuals identified to species. Meadowlarks (Sturnella spp.) and Le Conte’s Sparrows (Ammodramus leconteii) were the second (10 percent) and third (7 percent) most abundant bird species, respectively. Six of the seven most abundant species detected in grasslands were grassland species, and their numbers accounted for 87 percent of all birds, but 20 of the 30 species (67 percent) that used grasslands were not grassland species. Seven species observed in grassland transects during the study were Species of Conservation Concern: Le Conte’s Sparrow, Sedge Wren (Cistothorus platensis), Grasshopper Sparrow (Ammodramus savannarum), Long-billed Curlew (Numenius americanus), Sprague’s Pipit (Anthus spragueii), Cassin’s Sparrow (Aimophila cassinii), and Loggerhead Shrike (Lanius ludovicianus). Native grasslands consistently supported greater bird species richness than exotic grasslands. In one winter, exotic grasslands supported more birds than native grasslands.Native grasslands were determined to have more forb cover, more bare ground, and greater plant species richness than exotic grasslands, whereas exotic grasslands were characterized by more grass cover and relatively greater vegetation density during dry years. Not only did these individual measures differ between native and exotic grasslands, but components of variation also differed. In native grasslands, grass density and cover contributed more to variation, whereas in exotic grasslands, non-grass vegetation was a greater component of variation. Total bird numbers and bird species richness in native grasslands were related to the principal component that contained a measure of litter cover. Total bird numbers and bird species richness in exotic grasslands indicated no significant relationships with any of the principal components of variation.The two most common insect orders in native grasslands were Hymenoptera and Coleoptera, which accounted for 42 percent of all insects. The two most common insect orders in exotic grasslands were Hemiptera and Homoptera, which accounted for about 80 percent of all insects. Insect family richness was greater in exotic grasslands than in native grasslands in two of four seasons. Proportions of arachnid families were similar in native and exotic grasslands, but arachnid family richness was greater in exotic grasslands than in native grasslands.Abundance of seeds was greater in exotic than in native grasslands. However, seed diversity was greater in native grasslands than in exotic grasslands.Among the three types of management (mowed, burned, and control) applied to exotic grasses, birds were most abundant in the mowed area. Sedge Wrens, however, were never encountered in mowed sites. Meadowlarks were similarly abundant in all treatments, but Le Conte’s Sparrows were detected only in the control (unmanaged) area. Hispid cotton rats (Sigmodon hispidus) accounted for 93 percent of all rodent captures, with the number of captures peaking December through February. Hispid cotton rat numbers and total rodent numbers were greatest in control and pre-burn areas, and lowest in the mowed area. Mammal diversity, however, was greatest in the mowed habitat.Native and exotic grasslands differed essentially in all categories (bird numbers and diversity, vegetation characteristics, components of variation, diversity of insects and arachnids, and seed abundance and diversity) used to measure and compare them. This indicates that fundamental ecosystem processes have been altered after native grasslands have undergone invasion and ultimate domination by exotic grass species. Future research in Texas grassland ecosystems is essential because: 1) Texas sustains more area in grasslands than any other state or province in the Central Flyway; 2) Texas serves as the winter destination or migration pathway for hundreds of species of birds, including winter residents and Neotropical migrants; 3) ecology, distribution, and numbers of grassland birds wintering in southern latitudes of the United States remains poorly understood; and 4) climate change threatens to further accelerate advances of invading grass species.

Woodward Effect Experimental Verifications

NASA Astrophysics Data System (ADS)

March, Paul

2004-02-01

The work of J. F. Woodward (1990 1996a; 1996b; 1998; 2002a; 2002b; 2004) on the existence of ``mass fluctuations'' and their use in exotic propulsion schemes was examined for possible application in improving space flight propulsion and power generation. Woodward examined Einstein's General Relativity Theory (GRT) and assumed that if the strong Machian interpretation of GRT as well as gravitational / inertia like Wheeler-Feynman radiation reaction forces hold, then when an elementary particle is accelerated through a potential gradient, its rest mass should fluctuate around its mean value during its acceleration. Woodward also used GRT to clarify the precise experimental conditions necessary for observing and exploiting these mass fluctuations or ``Woodward effect'' (W-E). Later, in collaboration with his ex-graduate student T. Mahood, they also pushed the experimental verification boundaries of these proposals. If these purported mass fluctuations occur as Woodward claims, and his assumption that gravity and inertia are both byproducts of the same GRT based phenomenon per Mach's Principle is correct, then many innovative applications such as propellantless propulsion and gravitational exotic matter generators may be feasible. This paper examines the reality of mass fluctuations and the feasibility of using the W-E to design propellantless propulsion devices in the near to mid-term future. The latest experimental results, utilizing MHD-like force rectification systems, will also be presented.

Why do people use exotic plants in their local medical systems? A systematic review based on Brazilian local communities

PubMed Central

Ferreira Júnior, Washington Soares; Ramos, Marcelo Alves; da Silva, Taline Cristina; Ladio, Ana Haydée; Albuquerque, Ulysses Paulino

2017-01-01

Efforts have been made to understand the processes that lead to the introduction of exotic species into local pharmacopoeias. Among those efforts, the diversification hypothesis predicts that exotic plants are introduced in local medical systems to amplify the repertoire of knowledge related to the treatment of diseases, filling blanks that were not occupied by native species. Based on such hypothesis, this study aimed to contribute to this discussion using the context of local Brazilian populations. We performed a systematic review of Brazilian studies up to 2011 involving medicinal plants, excluding those studies that presented a high risk of bias (because of sampling or plant identification problems). An analysis of similarities (ANOSIM) was conducted in different scales to test for differences in the repertoire of therapeutic indications treated using native and exotic species. We have found that although there is some overlap between native and exotic plants regarding their therapeutic indications and the body systems (BSs) that they treat, there are clear gaps present, that is, there are therapeutic indications and BSs treated that are exclusive to exotic species. This scenario enables the postulation of two alternative unfoldings of the diversification hypothesis, namely, (1) exotic species are initially introduced to fill gaps and undergo subsequent expansion of their use for medical purposes already addressed using native species and (2) exotic species are initially introduced to address problems already addressed using native species to diversify the repertoire of medicinal plants and to increase the resilience of medical systems. The reasons why exotic species may have a competitive advantage over the native ones, the implications of the introduction of exotic species for the resilience of medical systems, and the contexts in which autochthonous plants can gain strength to remain in pharmacopoeias are also discussed. PMID:28953960

Bottom-up control of consumers leads to top-down indirect facilitation of invasive annual herbs in semiarid Chile.

PubMed

Madrigal, Jaime; Kelt, Douglas A; Meserve, Peter L; Gutierrez, Julio R; Squeo, Francisco A

2011-02-01

The abundance of exotic plants is thought to be limited by competition with resident species (including plants and generalist herbivores). In contrast, observations in semiarid Chile suggest that a native generalist rodent, the degu (Octodon degus), may be facilitating the expansion of exotic annual plants. We tested this hypothesis with a 20-year data set from a World Biosphere Reserve in mediterranean Chile. In this semiarid environment, rainfall varies annually and dramatically influences cover by both native and exotic annual plants; degu population density affects the composition and cover of exotic and native annual plants. In low-rainfall years, cover of both native and exotic herbs is extremely low. Higher levels of precipitation result in proportional increases in cover of all annual plants (exotic and native species), leading in turn to increases in degu population densities, at which point they impact native herbs in proportion to their greater cover, indirectly favoring the expansion of exotic plants. We propose that bottom-up control of consumers at our site results in top-down indirect facilitation of invasive annual herbs, and that this pattern may be general to other semiarid ecosystems.

Native weeds and exotic plants: relationships to disturbance in mixed grass prairie

USGS Publications Warehouse

Larson, D.L.

2003-01-01

The paper compares distributions of native weedy species and exotic species with respect to three kinds of disturbance, roads, trails, and prairie dog towns. Data were collected at the north and south units of Theodore Roosevelt National Park and at Wind Cave National Park. The paper concludes that many exotic species differ substantially from native weeds in their exploitation of disturbance. It is thus not useful to manage exotics as if they were just another weed.

Native and exotic plants of fragments of sagebrush steppe produced by geomorphic processes versus land use

USGS Publications Warehouse

Huntly, N.; Bangert, R.; Hanser, S.E.

2011-01-01

Habitat fragmentation and invasion by exotic species are regarded as major threats to the biodiversity of many ecosystems. We surveyed the plant communities of two types of remnant sagebrush-steppe fragments from nearby areas on the Snake River Plain of southeastern Idaho, USA. One type resulted from land use (conversion to dryland agriculture; hereafter AG Islands) and the other from geomorphic processes (Holocene volcanism; hereafter kipukas). We assessed two predictions for the variation in native plant species richness of these fragments, using structural equation models (SEM). First, we predicted that the species richness of native plants would follow the MacArthur-Wilson (M-W) hypothesis of island biogeography, as often is expected for the communities of habitat fragments. Second, we predicted a negative relationship between native and exotic plants, as would be expected if exotic plants are decreasing the diversity of native plants. Finally, we assessed whether exotic species were more strongly associated with the fragments embedded in the agricultural landscape, as would be expected if agriculture had facilitated the introduction and naturalization of non-native species, and whether the communities of the two types of fragments were distinct. Species richness of native plants was not strongly correlated with M-W characteristics for either the AG Islands or the **kipukas. The AG Islands had more species and higher cover of exotics than the kipukas, and exotic plants were good predictors of native plant species richness. Our results support the hypothesis that proximity to agriculture can increase the diversity and abundance of exotic plants in native habitat. In combination with other information, the results also suggest that agriculture and exotic species have caused loss of native diversity and reorganization of the sagebrush-steppe plant community. ?? 2011 Springer Science+Business Media B.V.

Exotic snakes are not always found in exotic places: how poison centres can assist emergency departments

PubMed Central

Lubich, Carol; Krenzelok, Edward P

2009-01-01

Emergency departments throughout the USA may have some familiarity with the management of envenomation from indigenous snake species such as Crotalinae (rattlesnakes) and Micrurus (coral snakes). However, venomous species may include exotic reptiles whose bites pose substantial treatment challenges due to both a lack of experience and the difficulty in obtaining antivenoms. Two pet cobra envenomation incidents illustrate the challenges that face emergency departments, especially in urban settings, that are confronted with these exposures. It is important for emergency departments to be aware of the large underground presence of exotic venomous reptile pets and to utilise the expertise of regional poison centres that will also assist in the procurement of exotic antivenoms. PMID:21686401

Exotic snakes are not always found in exotic places: how poison centres can assist emergency departments.

PubMed

Lubich, Carol; Krenzelok, Edward P

2009-01-01

Emergency departments throughout the USA may have some familiarity with the management of envenomation from indigenous snake species such as Crotalinae (rattlesnakes) and Micrurus (coral snakes). However, venomous species may include exotic reptiles whose bites pose substantial treatment challenges due to both a lack of experience and the difficulty in obtaining antivenoms. Two pet cobra envenomation incidents illustrate the challenges that face emergency departments, especially in urban settings, that are confronted with these exposures. It is important for emergency departments to be aware of the large underground presence of exotic venomous reptile pets and to utilise the expertise of regional poison centres that will also assist in the procurement of exotic antivenoms.

Exotic snakes are not always found in exotic places: how poison centres can assist emergency departments

PubMed Central

Lubich, Carol; Krenzelok, Edward P

2007-01-01

Emergency departments throughout the USA may have some familiarity with the management of envenomation from indigenous snake species such as Crotalinae (rattlesnakes) and Micrurus (coral snakes). However, venomous species may include exotic reptiles whose bites pose substantial treatment challenges due to both a lack of experience and the difficulty in obtaining antivenoms. Two pet cobra envenomation incidents illustrate the challenges that face emergency departments, especially in urban settings, that are confronted with these exposures. It is important for emergency departments to be aware of the large underground presence of exotic venomous reptile pets and to utilise the expertise of regional poison centres that will also assist in the procurement of exotic antivenoms. PMID:17954846

Exotic snakes are not always found in exotic places: how poison centres can assist emergency departments.

PubMed

Lubich, Carol; Krenzelok, Edward P

2007-11-01

Emergency departments throughout the USA may have some familiarity with the management of envenomation from indigenous snake species such as Crotalinae (rattlesnakes) and Micrurus (coral snakes). However, venomous species may include exotic reptiles whose bites pose substantial treatment challenges due to both a lack of experience and the difficulty in obtaining antivenoms. Two pet cobra envenomation incidents illustrate the challenges that face emergency departments, especially in urban settings, that are confronted with these exposures. It is important for emergency departments to be aware of the large underground presence of exotic venomous reptile pets and to utilise the expertise of regional poison centres that will also assist in the procurement of exotic antivenoms.

Biodiversity maintenance mechanisms differ between native and novel exotic-dominated communities

USDA-ARS?s Scientific Manuscript database

The ongoing homogenization of the Earth’s biota is affecting nearly every region of Earth. We experimentally compared species diversity decline between nine-species grassland communities containing either all exotic (i.e. introduced) or all native species under controlled field conditions. Exotic ...

Exotic germplasm introgression effects on adapted cotton genotypes

USDA-ARS?s Scientific Manuscript database

Our research is mainly focused on the objective of determining the effect of exotic germplasm introgression on agronomic and fiber properties of adapted cotton varieties. For this we studied eight populations derived by crossing two exotic parents (TX 245 and TX 1419) with four locally adapted culti...

Established perennial vegetation provides high resistance to reinvasion by exotic annual grasses

USDA-ARS?s Scientific Manuscript database

Exotic annual grasses have invaded millions of hectares of sagebrush (Artemisia L.) steppe in the Great Basin region and degraded wildlife habitat, reduced forage production, and promoted increasingly frequent wildfires. Revegetation after control of exotic annual grasses is needed to restore ecosy...

Biodiversity and native plant abundance decline with increasing abundance of exotic annual grass

USDA-ARS?s Scientific Manuscript database

Exotic plants are generally considered a serious problem in wildlands around the world. However, some argue that the impacts of exotic plants have been exaggerated and that biodiversity and other important plant community characteristics are commonly improved with invasion. Thus, disagreement exis...

The SPES High Power ISOL production target

NASA Astrophysics Data System (ADS)

Andrighetto, A.; Corradetti, S.; Ballan, M.; Borgna, F.; Manzolaro, M.; Scarpa, D.; Monetti, A.; Rossignoli, M.; Silingardi, R.; Mozzi, A.; Vivian, G.; Boratto, E.; De Ruvo, L.; Sattin, N.; Meneghetti, G.; Oboe, R.; Guerzoni, M.; Margotti, A.; Ferrari, M.; Zenoni, A.; Prete, G.

2016-11-01

SPES (Selective Production of Exotic Species) is a facility under construction at INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro), aimed to produce intense neutron-rich radioactive ion beams (RIBs). These will be obtained using the ISOL (Isotope Separation On-Line) method, bombarding a uranium carbide target with a proton beam of 40MeV energy and currents up to 200μA. The target configuration was designed to obtain a high number of fissions, up to 1013 per second, low power deposition and fast release of the produced isotopes. The exotic isotopes generated in the target are ionized, mass separated and re-accelerated by the ALPI superconducting LINAC at energies of 10AMeV and higher, for masses in the region of A = 130 amu , with an expected rate on the secondary target up to 109 particles per second. In this work, recent results on the R&D activities regarding the SPES RIB production target-ion source system are reported.

Nutrient addition shifts plant community composition towards earlier flowering species in some prairie ecoregions in the U.S. Central Plains.

PubMed

Biederman, Lori; Mortensen, Brent; Fay, Philip; Hagenah, Nicole; Knops, Johannes; La Pierre, Kimberly; Laungani, Ramesh; Lind, Eric; McCulley, Rebecca; Power, Sally; Seabloom, Eric; Tognetti, Pedro

2017-01-01

The distribution of flowering across the growing season is governed by each species' evolutionary history and climatic variability. However, global change factors, such as eutrophication and invasion, can alter plant community composition and thus change the distribution of flowering across the growing season. We examined three ecoregions (tall-, mixed, and short-grass prairie) across the U.S. Central Plains to determine how nutrient (nitrogen (N), phosphorus, and potassium (+micronutrient)) addition alters the temporal patterns of plant flowering traits. We calculated total community flowering potential (FP) by distributing peak-season plant cover values across the growing season, allocating each species' cover to only those months in which it typically flowers. We also generated separate FP profiles for exotic and native species and functional group. We compared the ability of the added nutrients to shift the distribution of these FP profiles (total and sub-groups) across the growing season. In all ecoregions, N increased the relative cover of both exotic species and C3 graminoids that flower in May through August. The cover of C4 graminoids decreased with added N, but the response varied by ecoregion and month. However, these functional changes only aggregated to shift the entire community's FP profile in the tall-grass prairie, where the relative cover of plants expected to flower in May and June increased and those that flower in September and October decreased with added N. The relatively low native cover in May and June may leave this ecoregion vulnerable to disturbance-induced invasion by exotic species that occupy this temporal niche. There was no change in the FP profile of the mixed and short-grass prairies with N addition as increased abundance of exotic species and C3 graminoids replaced other species that flower at the same time. In these communities a disturbance other than nutrient addition may be required to disrupt phenological patterns.

Nutrient addition shifts plant community composition towards earlier flowering species in some prairie ecoregions in the U.S. Central Plains

PubMed Central

Mortensen, Brent; Fay, Philip; Hagenah, Nicole; Knops, Johannes; La Pierre, Kimberly; Laungani, Ramesh; Lind, Eric; McCulley, Rebecca; Power, Sally; Seabloom, Eric; Tognetti, Pedro

2017-01-01

The distribution of flowering across the growing season is governed by each species’ evolutionary history and climatic variability. However, global change factors, such as eutrophication and invasion, can alter plant community composition and thus change the distribution of flowering across the growing season. We examined three ecoregions (tall-, mixed, and short-grass prairie) across the U.S. Central Plains to determine how nutrient (nitrogen (N), phosphorus, and potassium (+micronutrient)) addition alters the temporal patterns of plant flowering traits. We calculated total community flowering potential (FP) by distributing peak-season plant cover values across the growing season, allocating each species’ cover to only those months in which it typically flowers. We also generated separate FP profiles for exotic and native species and functional group. We compared the ability of the added nutrients to shift the distribution of these FP profiles (total and sub-groups) across the growing season. In all ecoregions, N increased the relative cover of both exotic species and C3 graminoids that flower in May through August. The cover of C4 graminoids decreased with added N, but the response varied by ecoregion and month. However, these functional changes only aggregated to shift the entire community’s FP profile in the tall-grass prairie, where the relative cover of plants expected to flower in May and June increased and those that flower in September and October decreased with added N. The relatively low native cover in May and June may leave this ecoregion vulnerable to disturbance-induced invasion by exotic species that occupy this temporal niche. There was no change in the FP profile of the mixed and short-grass prairies with N addition as increased abundance of exotic species and C3 graminoids replaced other species that flower at the same time. In these communities a disturbance other than nutrient addition may be required to disrupt phenological patterns. PMID:28552986

Prefire (preemptive) management to decrease fire-induced bunchgrass mortality and reduce reliance on postfire seeding

USDA-ARS?s Scientific Manuscript database

Western rangelands are currently under severe threat from exotic annual grasses. To successfully manage rangelands that are either infested with or susceptible to exotic annual grasses, we must focus on increasing resilience to disturbance and resistance to exotic annual grass invasion. Here, we p...

Rapid detection of exotic Lymantriids and Scolytids pilot study

Treesearch

Mary Ellen Dix

2003-01-01

Exotic invasive species, inadvertently introduced into North America through importation and travel, are threatening the integrity of North American forest ecosystems. The National Invasive Species Council in their 2001 Strategic Plan identified a collaborative program for early detection, diagnosis and response to high-risk, exotic, invasive insects, pathogens and...

Exotic plants as ecosystem dominants

Treesearch

Julie S. Denslow; R. Flint Hughes

2004-01-01

Dominant species have long been appreciated for their role in determining ecosystem attributes such as vegetation structure, successional patterns, soil characteristics, hydrology, and productivity. Exotic species may reach such high densities that they become community dominants, and it is in this role that exotics pose the greatest threat to native ecosystems. Four...

Predicting invasion in grassland ecosystems: Is exotic dominance the real embarrassment of richness?

USDA-ARS?s Scientific Manuscript database

For two centuries there has been a perception that while exotic species are dominant in many areas, others remain largely unaffected. This unquantified observation suggests a fundamental ecological question: why do exotics dominate some locations and not others? While invasions are clearly important...

Exotic plant species attack revegetation plants in post-coal mining areas

NASA Astrophysics Data System (ADS)

Yusuf, Muhammad; Arisoesilaningsih, Endang

2017-11-01

This study aimed to explore some invasive exotic plant species that have the potential to disrupt the growth of revegetation plants in post-coal mining areas. This research was conducted in a revegetation area of PT, Amanah Anugerah Adi Mulia (A3M) Kintap site, South Borneo. Direct observation was carried out on some revegetation areas by observing the growth of revegetation plants disturbed by exotic plant species and the spread of exotic plant species. Based on observation, several invasive exotic plant species were identified including Mikania cordata, Centrosema pubescence, Calopogonium mucunoides, Mimosa pudica, Ageratum conyzoides, and Chromolaena odorata. These five plant species grew wild in the revegetation area and showed ability to disrupt the growth of other plants. In some tree species, such as Acacia mangium, Paraserianthes falcataria, M. cordata could inhibit the growth and even kill the trees through covering the tree canopy. So, the trees could not receive optimum sun light for photosynthesis processes. M. cordata was also observed to have the most widespread distribution. Several exotic plant species such as C. mucunoides, M. pudica, and A. conyzoides were observed to have deep root systems compared with plant species used for revegetation. This growth characteristic allowed exotic plant species to win the competition for nutrient absorption with other plant species.

Enhancing early detection of exotic pests in agricultural and forest ecosystems using an urban-gradient framework.

PubMed

Colunga-Garcia, Manuel; Magarey, Roger A; Haack, Robert A; Gage, Stuart H; Qi, Jiaquo

2010-03-01

Urban areas are hubs of international transport and therefore are major gateways for exotic pests. Applying an urban gradient to analyze this pathway could provide insight into the ecological processes involved in human-mediated invasions. We defined an urban gradient for agricultural and forest ecosystems in the contiguous United States to (1) assess whether ecosystems nearer more urbanized areas were at greater risk of invasion, and (2) apply this knowledge to enhance early detection of exotic pests. We defined the gradient using the tonnage of imported products in adjacent urban areas and their distance to nearby agricultural or forest land. County-level detection reports for 39 exotic agricultural and forest pests of major economic importance were used to characterize invasions along the gradient. We found that counties with more exotic pests were nearer the urban end of the gradient. Assuming that the exotic species we analyzed represent typical invaders, then early detection efforts directed at 21-26% of U.S. agricultural and forest land would likely be able to detect 70% of invaded counties and 90% of the selected species. Applying an urban-gradient framework to current monitoring strategies should enhance early detection efforts of exotic pests, facilitating optimization in allocating resources to areas at greater risk of future invasions.

Exotic Meson Results from BNL E852

NASA Astrophysics Data System (ADS)

Manak, Joseph J.

1998-10-01

Results from BNL experiment 852 on exotic (non-q\\overlineq) meson production are presented. Production of final states with J^PC = 1^-+ is observed in π^-p interactions at 18 GeV/c in the ηπ^-, ρπ^- and η^'π^- channels. Since such states are manifestly exotic if they are resonant, we describe amplitude analyses which use the interference between these states and other well known states to measure the phase behavior of the J^PC = 1^-+ amplitudes. The analyses show that, in addition to the previously reported(D.R. Thompson et al.), Phys. Rev. Lett. 79, 1630 (1997) evidence for an exotic meson in the ηπ^- channel, there is strong evidence for a second exotic meson decaying to ρπ^- with a mass of M=1593 ±8^+29_-47 MeV/c^2 and a width of Γ=168 ±20^+150_-12 MeV/c^2. We also show that the η^'π^- system is dominated by J^PC = 1^-+ production and we use those data to determine decay branching ratios for the exotic mesons. Such measurements are expected to be crucial in determining the constituent nature of the exotic mesons - that is, whether they are consistent with being hybrid mesons or four-quark states.

Quantum Emitters in Two-Dimensional Structured Reservoirs in the Nonperturbative Regime

NASA Astrophysics Data System (ADS)

González-Tudela, A.; Cirac, J. I.

2017-10-01

We show that the coupling of quantum emitters to a two-dimensional reservoir with a simple band structure gives rise to exotic quantum dynamics with no analogue in other scenarios and which cannot be captured by standard perturbative treatments. In particular, for a single quantum emitter with its transition frequency in the middle of the band, we predict an exponential relaxation at a rate different from that predicted by Fermi's golden rule, followed by overdamped oscillations and slow relaxation decay dynamics. This is accompanied by directional emission into the reservoir. This directionality leads to a modification of the emission rate for few emitters and even perfect subradiance, i.e., suppression of spontaneous emission, for four quantum emitters.

Mobile bound states of Rydberg excitations in a lattice

NASA Astrophysics Data System (ADS)

Letscher, Fabian; Petrosyan, David

2018-04-01

Spin-lattice models play a central role in the studies of quantum magnetism and nonequilibrium dynamics of spin excitations—-magnons. We show that a spin lattice with strong nearest-neighbor interactions and tunable long-range hopping of excitations can be realized by a regular array of laser-driven atoms, with an excited Rydberg state representing the spin-up state and a Rydberg-dressed ground state corresponding to the spin-down state. We find exotic interaction-bound states of magnons that propagate in the lattice via the combination of resonant two-site hopping and nonresonant second-order hopping processes. Arrays of trapped Rydberg-dressed atoms can thus serve as a flexible platform to simulate and study fundamental few-body dynamics in spin lattices.

Exotic pediculosis and hair-loss syndrome in deer (Odocoileus hemionus) populations in California.

PubMed

Roug, Annette; Swift, Pamela; Puschner, Birgit; Gerstenberg, Greg; Mertins, James W; Johnson, Christine Kreuder; Torres, Steve; Mortensen, Jack; Woods, Leslie

2016-07-01

Infestation with nonnative, "exotic" lice was first noted in Washington black-tailed deer (Odocoileus hemionus columbianus) in 1994 and has since then spread throughout the western United States. In California, infestation with the exotic louse Damalinia (Cervicola) sp. was first detected in black-tailed deer from northern California in 2004, and, in 2009, the exotic louse species Bovicola tibialis and Linognathus africanus were identified on mule deer (Odocoileus hemionus californicus) in central Sierra Nevada in association with a mortality event. Exotic lice have since been detected in various locations throughout the state. We describe the geographic distribution of these exotic lice within California, using data from 520 live-captured and 9 postmortem-sampled, free-ranging mule deer examined between 2009 and 2014. Data from live-captured deer were used to assess possible associations between louse infestation and host age, host sex, migratory behavior, season, and blood selenium and serum copper concentrations. Damalinia (Cervicola) sp. and B. tibialis lice were distinctively distributed geographically, with D. (Cervicola) sp. infesting herds in northern and central coastal California, B. tibialis occurring in the central coastal mountains and the Sierra Nevada, and L. africanus occurring only sporadically. Younger age classes and low selenium concentrations were significantly associated with exotic louse infestation, whereas no significant relationship was detected with serum copper levels. Our results show that exotic lice are widespread in California, and younger age classes with low blood selenium concentrations are more likely to be infested with lice than older deer. © 2016 The Author(s).

Soil biotic legacy effects of extreme weather events influence plant invasiveness

PubMed Central

Meisner, Annelein; De Deyn, Gerlinde B.; de Boer, Wietse; van der Putten, Wim H.

2013-01-01

Climate change is expected to increase future abiotic stresses on ecosystems through extreme weather events leading to more extreme drought and rainfall incidences [Jentsch A, et al. (2007) Front Ecol Environ 5(7):365–374]. These fluctuations in precipitation may affect soil biota, soil processes [Evans ST, Wallenstein MD (2012) Biogeochemistry 109:101–116], and the proportion of exotics in invaded plant communities [Jiménez MA, et al. (2011) Ecol Lett 14:1277–1235]. However, little is known about legacy effects in soil on the performance of exotics and natives in invaded plant communities. Here we report that drought and rainfall effects on soil processes and biota affect the performance of exotics and natives in plant communities. We performed two mesocosm experiments. In the first experiment, soil without plants was exposed to drought and/or rainfall, which affected soil N availability. Then the initial soil moisture conditions were restored, and a mixed community of co-occurring natives and exotics was planted and exposed to drought during growth. A single stress before or during growth decreased the biomass of natives, but did not affect exotics. A second drought stress during plant growth resetted the exotic advantage, whereas native biomass was not further reduced. In the second experiment, soil inoculation revealed that drought and/or rainfall influenced soil biotic legacies, which promoted exotics but suppressed natives. Our results demonstrate that extreme weather events can cause legacy effects in soil biota, promoting exotics and suppressing natives in invaded plant communities, depending on the type, frequency, and timing of extreme events. PMID:23716656

Temperature-dependent shifts in phenology contribute to the success of exotic species with climate change.

PubMed

Wolkovich, Elizabeth M; Davies, T Jonathan; Schaefer, Hanno; Cleland, Elsa E; Cook, Benjamin I; Travers, Steven E; Willis, Charles G; Davis, Charles C

2013-07-01

The study of how phenology may contribute to the assembly of plant communities has a long history in ecology. Climate change has brought renewed interest in this area, with many studies examining how phenology may contribute to the success of exotic species. In particular, there is increasing evidence that exotic species occupy unique phenological niches and track climate change more closely than native species. Here, we use long-term records of species’ first flowering dates from fi ve northern hemisphere temperate sites (Chinnor, UK and in the United States, Concord, Massachusetts; Fargo, North Dakota; Konza Prairie, Kansas; and Washington,D.C.) to examine whether invaders have distinct phenologies. Using a broad phylogenetic framework, we tested for differences between exotic and native species in mean annual flowering time, phenological changes in response to temperature and precipitation,and longer-term shifts in first flowering dates during recent pronounced climate change (“flowering time shifts”). Across North American sites, exotic species have shifted flowering with climate change while native species, on average, have not. In the three mesic systems, exotic species exhibited higher tracking of interannual variation in temperature,such that flowering advances more with warming, than native species. Across the two grassland systems, however, exotic species differed from native species primarily in responses to precipitation and soil moisture, not temperature. Our findings provide cross-site support for the role of phenology and climate change in explaining species’ invasions.Further, they support recent evidence that exotic species may be important drivers of extended growing seasons observed with climate change in North America.

Generation of flower high-order Poincaré sphere laser beams from a spatial light modulator

NASA Astrophysics Data System (ADS)

Lu, T. H.; Huang, T. D.; Wang, J. G.; Wang, L. W.; Alfano, R. R.

2016-12-01

We propose and experimentally demonstrate a new complex laser beam with inhomogeneous polarization distributions mapping onto high-order Poincaré spheres (HOPSs). The complex laser mode is achieved by superposition of Laguerre-Gaussian modes and manifests exotic flower-like localization on intensity and phase profiles. A simple optical system is used to generate a polarization-variant distribution on the complex laser mode by superposition of orthogonal circular polarizations with opposite topological charges. Numerical analyses of the polarization distribution are consistent with the experimental results. The novel flower HOPS beams can act as a new light source for photonic applications.

Extreme climatic events change the dynamics and invasibility of semi-arid annual plant communities.

PubMed

Jiménez, Milagros A; Jaksic, Fabian M; Armesto, Juan J; Gaxiola, Aurora; Meserve, Peter L; Kelt, Douglas A; Gutiérrez, Julio R

2011-12-01

Extreme climatic events represent disturbances that change the availability of resources. We studied their effects on annual plant assemblages in a semi-arid ecosystem in north-central Chile. We analysed 130 years of precipitation data using generalised extreme-value distribution to determine extreme events, and multivariate techniques to analyse 20 years of plant cover data of 34 native and 11 exotic species. Extreme drought resets the dynamics of the system and renders it susceptible to invasion. On the other hand, by favouring native annuals, moderately wet events change species composition and allow the community to be resilient to extreme drought. The probability of extreme drought has doubled over the last 50 years. Therefore, investigations on the interaction of climate change and biological invasions are relevant to determine the potential for future effects on the dynamics of semi-arid annual plant communities. 2011 Blackwell Publishing Ltd/CNRS.

The dynamics of aloof baby Skyrmions

DOE PAGES

Salmi, Petja; Sutcliffe, Paul

2016-01-25

The aloof baby Skyrme model is a (2+1)-dimensional theory with solitons that are lightly bound. It is a low-dimensional analogue of a similar Skyrme model in (3+1)- dimensions, where the lightly bound solitons have binding energies comparable to nuclei. A previous study of static solitons in the aloof baby Skyrme model revealed that multi-soliton bound states have a cluster structure, with constituents that preserve their individual identities due to the short-range repulsion and long-range attraction between solitons. Furthermore, there are many different local energy minima that are all well-described by a simple binary species particle model. In this paper wemore » present the first results on soliton dynamics in the aloof baby Skyrme model. Numerical field theory simulations reveal that the lightly bound cluster structure results in a variety of exotic soliton scattering events that are novel in comparison to standard Skyrmion scattering. A dynamical version of the binary species point particle model is shown to provide a good qualitative description of the dynamics.« less

The dynamics of aloof baby Skyrmions

NASA Astrophysics Data System (ADS)

Salmi, Petja; Sutcliffe, Paul

2016-01-01

The aloof baby Skyrme model is a (2+1)-dimensional theory with solitons that are lightly bound. It is a low-dimensional analogue of a similar Skyrme model in (3+1)-dimensions, where the lightly bound solitons have binding energies comparable to nuclei. A previous study of static solitons in the aloof baby Skyrme model revealed that multi-soliton bound states have a cluster structure, with constituents that preserve their individual identities due to the short-range repulsion and long-range attraction between solitons. Furthermore, there are many different local energy minima that are all well-described by a simple binary species particle model. In this paper we present the first results on soliton dynamics in the aloof baby Skyrme model. Numerical field theory simulations reveal that the lightly bound cluster structure results in a variety of exotic soliton scattering events that are novel in comparison to standard Skyrmion scattering. A dynamical version of the binary species point particle model is shown to provide a good qualitative description of the dynamics.

Observation of symmetry-protected topological band with ultracold fermions

PubMed Central

Song, Bo; Zhang, Long; He, Chengdong; Poon, Ting Fung Jeffrey; Hajiyev, Elnur; Zhang, Shanchao; Liu, Xiong-Jun; Jo, Gyu-Boong

2018-01-01

Symmetry plays a fundamental role in understanding complex quantum matter, particularly in classifying topological quantum phases, which have attracted great interests in the recent decade. An outstanding example is the time-reversal invariant topological insulator, a symmetry-protected topological (SPT) phase in the symplectic class of the Altland-Zirnbauer classification. We report the observation for ultracold atoms of a noninteracting SPT band in a one-dimensional optical lattice and study quench dynamics between topologically distinct regimes. The observed SPT band can be protected by a magnetic group and a nonlocal chiral symmetry, with the band topology being measured via Bloch states at symmetric momenta. The topology also resides in far-from-equilibrium spin dynamics, which are predicted and observed in experiment to exhibit qualitatively distinct behaviors in quenching to trivial and nontrivial regimes, revealing two fundamental types of spin-relaxation dynamics related to bulk topology. This work opens the way to expanding the scope of SPT physics with ultracold atoms and studying nonequilibrium quantum dynamics in these exotic systems. PMID:29492457

Riparian zones as havens for exotic plant species in the central grasslands

USGS Publications Warehouse

Stohlgren, T.J.; Bull, K.A.; Otsuki, Yuka; Villa, C.A.; Lee, M.

1998-01-01

In the Central Grasslands of the United States, we hypothesized that riparian zones high in soil fertility would contain more exotic plant species than upland areas of low soil fertility. Our alternate hypothesis was that riparian zones high in native plant species richness and cover would monopolize available resources and resist invasion by exotic species. We gathered nested-scale vegetation data from 40 1 m2subplots (nested in four 1000 m2 plots) in both riparian and upland sites at four study areas in Colorado, Wyoming, and South Dakota (a total of 320 1 m2subplots and 32 1000 m2 plots). At the 1 m2 scale, mean foliar cover of native species was significantly greater (P < 0.001) in riparian zones (36.6% ?? 1.7%) compared to upland sites (28.7% ?? 1.5%), but at this small scale there were no consistent patterns of native and exotic species richness among the four management areas. Mean exotic species cover was slightly higher in upland sites compared to riparian sites (9.0% ?? 3.8% versus 8.2% ?? 3.0% cover). However, mean exotic species richness and cover were greater in the riparian zones than upland sites in three of four management areas. At the 1000 m2 scale, mean exotic species richness was also significantly greater (P < 0.05) in riparian zones (7.8 ?? 1.0 species) compared to upland sites (4.8 ?? 1.0 species) despite the heavy invasion of one upland site. For all 32 plots combined, 21% of the variance in exotic species richness was explained by positive relationships with soil % silt (t = 1.7, P = 0.09) and total foliar cover (t = 2.4, P = 0.02). Likewise, 26% of the variance in exotic species cover (log10 cover) was explained by positive relationships with soil % silt (t = 2.3, P = 0.03) and total plant species richness (t = 2.4, P = 0.02). At landscape scales (four 1000 m2 plots per type combined), total foliar cover was significantly and positively correlated with exotic species richness (r = 0.73, P < 0.05) and cover (r = 0.74, P < 0.05). Exotic species cover (log10 cover) was positively correlated with log10% N in the soil (r = 0.61, P = 0.11) at landscape scales. On average, we found that 85% (??5%) of the total number of exotic species in the sampling plots of a given management area could be found in riparian zones, while only 50% (??8%) were found in upland plots. We conclude that: (1 species-rich and productive riparian zones are particularly invasible in grassland ecosystems; and (2) riparian zones may act as havens, corridors, and sources of exotic plant invasions for upland sites and pose a significant challenge to land managers and conservation biologists.

Exotic species patterns and function in urban landscapes

Treesearch

Wayne C. Zipperer

2003-01-01

Mack et al. (2000) state "Biotic invaders are species that establish a new range in which they proliferate, spread, and persist to the detriment of the environment." This statement is true for many natural landscapes. In urban landscapes, however, exotic species are critical components of the landscape and enhance its livability. Exotic species provide...

A review of impacts by invasive exotic plants on forest ecosystem services

Treesearch

Kevin Devine; Songlin Fei

2011-01-01

Many of our forest ecosystems are at risk due to the invasion of exotic invasive plant species. Invasive plant species pose numerous threats to ecosystems by decreasing biodiversity, deteriorating ecosystem processes, and degrading ecosystem services. Literature on Kentucky's most invasive exotic plant species was examined to understand their potential impacts on...

Incorporating seeds in activated carbon pellets limits herbicide effects to seeded bunchgrasses when controlling exotic annuals

USDA-ARS?s Scientific Manuscript database

Revegetation of exotic annual grass-invaded rangeland with pre-emergent herbicides is challenging because seeding is delayed until herbicide toxicity has diminished, but at this time, exotic annuals can be re-invading. Incorporating seeds into activated carbon pellets may allow seeding to occur at t...

Invasion of exotic earthworms into ecosystems inhabited by native earthworms

Treesearch

P.F. Hendrix; G.H. Baker; M.A. Jr. Callaham; G.A. Damoff; C. Fragoso; G. Gonzalez; S.W. James; S.L. Lachnicht; T. Winsome; X. Zou

2006-01-01

The most conspicuous biological invasions in terrestrial ecosystems have been by exotic plants, insects and vertebrates. Invasions by exotic earthworms, although not as well studied, may be increasing with global commerce in agriculture, waste management and bioremediation. A number of cases has documented where invasive earthworms have caused significant changes in...

The Exotic Pest Plant Council

Treesearch

Brian Bowen

1998-01-01

The Exotic Pest Plant Council (EPPC) is a proactive organization established to raise awareness about the threat posed by invasive exotic pest plants in natural areas and acts to stop the continued spread of invasive species. EPPC provides fora for sharing information and provides networking opportunities regarding all matters concerning this issue. EPPC was first...

Post-wildfire seeding to restore native vegetation and limit exotic annuals: an evaluation in juniper-dominated sagebrush steppe

USDA-ARS?s Scientific Manuscript database

Reestablishment of perennial vegetation is often need after wildfires to limit exotic species and restore ecosystem services. Some ecosystems, however, are resilient to disturbance and resistant to exotic plant invasions and do not require restoration efforts. If restoration is needed, an addition...

Invasive exotic plants in the tropical Pacific Islands: Patterns of Diversity

Treesearch

J.S. Denslow; J.C. Space; P.A. Thomas

2009-01-01

Oceanic islands are good model systems with which to explore factors affecting exotic species diversity. Islands vary in size, topography, substrate type, degree of isolation, native species diversity, history, human population characteristics, and economic development. Moreover, islands are highly vulnerable to exotic species establishment. We used AICc analyses of...

Response of native versus exotic plant guilds to cattle and elk herbivory in forested rangeland

Treesearch

Burak K. Pekin; Michael J. Wisdom; Catherine G. Parks; Bryan A. Endress; Bridgett J. Naylor; Ralf Ohlemuller

2015-01-01

Questions: Are exotic plant species favoured by non-native ungulate herbivores and disadvantaged by native herbivores in forested rangelands? Do the impacts of ungulates on exotic vs native plants depend on forest management activities such as prescribed fire and stand thinning?Location: Northeastern Oregon, USA....

Soil properties and exotic plant invasions: a two-way street

Treesearch

Joan G. Ehrenfeld

2003-01-01

Invasions of exotic plant species have become not only widespread but also a major threat to the health of native ecosystems. In order to manage these invasions, it is important to understand the changes that exotic plants may cause in the environment, and the signs that such changes are taking place.

50 CFR 15.26 - Approval of cooperative breeding programs.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-sustaining population in captivity of the exotic bird species; (iii) Details on the system of recordkeeping... the exotic bird species in the world; (v) Details on the funding of this program; and (vi) Plans for... program intended to enhance the survival of the population from which the exotic bird species was or would...

Human land use promotes the abundance and diversity of exotic species on caribbean islands.

PubMed

Jesse, Wendy A M; Behm, Jocelyn E; Helmus, Matthew R; Ellers, Jacintha

2018-05-31

Human land use causes major changes in species abundance and composition, yet native and exotic species can exhibit different responses to land use change. Native populations generally decline in human-impacted habitats while exotic species often benefit. In this study, we assessed the effects of human land use on exotic and native reptile diversity, including functional diversity, which relates to the range of habitat use strategies in biotic communities. We surveyed 114 reptile communities from localities that varied in habitat structure and human impact level on two Caribbean islands, and calculated species richness, overall abundance and evenness for every plot. Functional diversity indices were calculated using published trait data, which enabled us to detect signs of trait filtering associated with impacted habitats. Our results show that environmental variation among sampling plots was explained by two PCA ordination axes related to habitat structure (i.e. forest or non-forest) and human impact level (i.e. addition of man-made constructions such as roads and buildings). Several diversity indices were significantly correlated with the two PCA axes, but exotic and native species showed opposing responses. Native species reached the highest abundance in forests, while exotic species were absent in this habitat. Human impact was associated with an increase in exotic abundance and species richness, while native species showed no significant associations. Functional diversity was highest in non-forested environments on both islands, and further increased on St. Martin with the establishment of functionally unique exotic species in non-forested habitat. Habitat structure, rather than human impact, proved to be an important agent for environmental filtering of traits, causing divergent functional trait values across forested and non-forested environments. Our results illustrate the importance of considering various elements of land use when studying its impact on species diversity and the establishment and spread of exotic species. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Risk assessment of non-target effects caused by releasing two exotic phytoseiid mites in Japan: can an indigenous phytoseiid mite become IG prey?

PubMed

Sato, Yukie; Mochizuki, Atsushi

2011-08-01

Two exotic phytoseiid mites, Neoseiulus cucumeris and Amblyseius swirskii, are commercially available in Japan for the control of thrips and other pest insects. As part of a risk assessment of the non-target effects of releasing these two species, we investigated intraguild predation (IGP) between these exotic phytoseiid mites and an indigenous phytoseiid mite Gynaeseius liturivorus, which is promising as an indigenous natural enemy for the control of thrips in Japan. To understand IGP relations between the exotic and indigenous phytoseiid mites after use of the exotic mites for biological control, we investigated IGP between them in the absence of their shared prey. When an IG prey was offered to an IG predator, both exotic and indigenous females consumed the IG prey at all immature stages (egg, larva, protonymph, deutonymph), especially at its larval stages. The propensity for IGP in a no-choice test was measured by the survival time of IG prey corrected using the survival time of thrips offered to the IG predator. There was no significant difference in the propensity for IGP between N. cucumeris and G. liturivorus, but the propensity was significantly higher in A. swirskii than G. liturivorus. The propensity for IGP in a choice test was measured by the prey choice of the IG predator when a conspecific and a heterospecific larva were offered simultaneously as IG prey. Both exotic females consumed the heterospecific larva only. The indigenous female preferentially consumed the heterospecific larva when the heterospecific larva was N. cucumeris, but consumed the conspecific larva when the heterospecific larva was A. swirskii. We concluded that further investigation would be necessary for the exotic mites' risk assessment, since the propensity for IGP of the two exotic females was similar to or higher than that of the indigenous female in both the no-choice and choice tests.

Acceleration of exotic plant invasion in a forested ecosystem by a generalist herbivore.

PubMed

Eschtruth, Anne K; Battles, John J

2009-04-01

The successful invasion of exotic plants is often attributed to the absence of coevolved enemies in the introduced range (i.e., the enemy release hypothesis). Nevertheless, several components of this hypothesis, including the role of generalist herbivores, remain relatively unexplored. We used repeated censuses of exclosures and paired controls to investigate the role of a generalist herbivore, white-tailed deer (Odocoileus virginianus), in the invasion of 3 exotic plant species (Microstegium vimineum, Alliaria petiolata, and Berberis thunbergii) in eastern hemlock (Tsuga canadensis) forests in New Jersey and Pennsylvania (U.S.A.). This work was conducted in 10 eastern hemlock (T. canadensis) forests that spanned gradients in deer density and in the severity of canopy disturbance caused by an introduced insect pest, the hemlock woolly adelgid (Adelges tsugae). We used maximum likelihood estimation and information theoretics to quantify the strength of evidence for alternative models of the influence of deer density and its interaction with the severity of canopy disturbance on exotic plant abundance. Our results were consistent with the enemy release hypothesis in that exotic plants gained a competitive advantage in the presence of generalist herbivores in the introduced range. The abundance of all 3 exotic plants increased significantly more in the control plots than in the paired exclosures. For all species, the inclusion of canopy disturbance parameters resulted in models with substantially greater support than the deer density only models. Our results suggest that white-tailed deer herbivory can accelerate the invasion of exotic plants and that canopy disturbance can interact with herbivory to magnify the impact. In addition, our results provide compelling evidence of nonlinear relationships between deer density and the impact of herbivory on exotic species abundance. These findings highlight the important role of herbivore density in determining impacts on plant abundance and provide evidence of the operation of multiple mechanisms in exotic plant invasion.

Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar

PubMed Central

Farris, Zach J.; Golden, Christopher D.; Karpanty, Sarah; Murphy, Asia; Stauffer, Dean; Ratelolahy, Felix; Andrianjakarivelo, Vonjy; Holmes, Christopher M.; Kelly, Marcella J.

2015-01-01

The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore conservation worldwide. Utilizing photographic, line-transect, and habitat sampling, as well as landscape analyses and village-based bushmeat hunting surveys, we provide the first investigation of how multiple forms of habitat degradation (fragmentation, exotic carnivores, human encroachment, and hunting) affect carnivore occupancy across Madagascar’s largest protected area: the Masoala-Makira landscape. We found that as degradation increased, native carnivore occupancy and encounter rates decreased while exotic carnivore occupancy and encounter rates increased. Feral cats (Felis species) and domestic dogs (Canis familiaris) had higher occupancy than half of the native carnivore species across Madagascar’s largest protected landscape. Bird and small mammal encounter rates were negatively associated with exotic carnivore occupancy, but positively associated with the occupancy of four native carnivore species. Spotted fanaloka (Fossa fossana) occupancy was constrained by the presence of exotic feral cats and exotic small Indian civet (Viverricula indica). Hunting was intense across the four study sites where hunting was studied, with the highest rates for the small Indian civet (x¯ = 90 individuals consumed/year), the ring-tailed vontsira (Galidia elegans) (x¯ = 58 consumed/year), and the fosa (Cryptoprocta ferox) (x¯ = 31 consumed/year). Our modeling results suggest hunters target intact forest where carnivore occupancy, abundance, and species richness, are highest. These various anthropogenic pressures and their effects on carnivore populations, especially increases in exotic carnivores and hunting, have wide-ranging, global implications and demand effective management plans to target the influx of exotic carnivores and unsustainable hunting that is affecting carnivore populations across Madagascar and worldwide. PMID:26375991

Trade-off between early emergence and herbivore susceptibility mediates exotic success in an experimental California plant community.

PubMed

Waterton, Joseph; Cleland, Elsa E

2016-12-01

Ecological trade-offs are fundamental to theory in community ecology; critical for understanding species coexistence in diverse plant communities, as well as the evolution of diverse life-history strategies. Invasions by exotic species can provide insights into the importance of trade-offs in community assembly, because the ecological strategies of invading species often differ from those present in the native species pool. Exotic annual species have invaded many Mediterranean-climate areas around the globe, and often germinate and emerge earlier in the growing season than native species. Early-season growth can enable exotic annual species to preempt space and resources, competitively suppressing later-emerging native species; however, early-emerging individuals may also be more apparent to herbivores. This suggests a potential trade-off between seasonal phenology and susceptibility to herbivory. To evaluate this hypothesis, we monitored the emergence and growth of 12 focal species (six each native and exotic) in monoculture and polyculture, while experimentally excluding generalist herbivores both early and later in the growing season. Consistent with past studies, the exotic species emerged earlier than native species. Regardless of species origin, earlier-emerging species achieved greater biomass by the end of the experiment, but were more negatively impacted by herbivory, particularly in the early part of the growing season. This greater impact of early-season herbivory on early-active species led to a reduction in the competitive advantage of exotic species growing in polyculture, and improved the performance of later-emerging natives. Such a trade-off between early growth and susceptibility to herbivores could be an important force in community assembly in seasonal herbaceous-dominated ecosystems. These results also show how herbivore exclusion favors early-active exotic species in this system, with important implications for management in many areas invaded by early-active exotic species.

A predictive framework and review of the ecological impacts of exotic plant invasions on reptiles and amphibians.

PubMed

Martin, Leigh J; Murray, Brad R

2011-05-01

The invasive spread of exotic plants in native vegetation can pose serious threats to native faunal assemblages. This is of particular concern for reptiles and amphibians because they form a significant component of the world's vertebrate fauna, play a pivotal role in ecosystem functioning and are often neglected in biodiversity research. A framework to predict how exotic plant invasion will affect reptile and amphibian assemblages is imperative for conservation, management and the identification of research priorities. Here, we present a new predictive framework that integrates three mechanistic models. These models are based on exotic plant invasion altering: (1) habitat structure; (2) herbivory and predator-prey interactions; (3) the reproductive success of reptile and amphibian species and assemblages. We present a series of testable predictions from these models that arise from the interplay over time among three exotic plant traits (growth form, area of coverage, taxonomic distinctiveness) and six traits of reptiles and amphibians (body size, lifespan, home range size, habitat specialisation, diet, reproductive strategy). A literature review provided robust empirical evidence of exotic plant impacts on reptiles and amphibians from each of the three model mechanisms. Evidence relating to the role of body size and diet was less clear-cut, indicating the need for further research. The literature provided limited empirical support for many of the other model predictions. This was not, however, because findings contradicted our model predictions but because research in this area is sparse. In particular, the small number of studies specifically examining the effects of exotic plants on amphibians highlights the pressing need for quantitative research in this area. There is enormous scope for detailed empirical investigation of interactions between exotic plants and reptile and amphibian species and assemblages. The framework presented here and further testing of predictions will provide a basis for informing and prioritising environmental management and exotic plant control efforts. © 2010 The Authors. Biological Reviews © 2010 Cambridge Philosophical Society.

The influence of the free space environment on the superlight-weight thermal protection system: conception, methods, and risk analysis

NASA Astrophysics Data System (ADS)

Yatsenko, Vitaliy; Falchenko, Iurii; Fedorchuk, Viktor; Petrushynets, Lidiia

2016-07-01

This report focuses on the results of the EU project "Superlight-weight thermal protection system for space application (LIGHT-TPS)". The bottom line is an analysis of influence of the free space environment on the superlight-weight thermal protection system (TPS). This report focuses on new methods that based on the following models: synergetic, physical, and computational. This report concentrates on four approaches. The first concerns the synergetic approach. The synergetic approach to the solution of problems of self-controlled synthesis of structures and creation of self-organizing technologies is considered in connection with the super-problem of creation of materials with new functional properties. Synergetics methods and mathematical design are considered according to actual problems of material science. The second approach describes how the optimization methods can be used to determine material microstructures with optimized or targeted properties. This technique enables one to find unexpected microstructures with exotic behavior (e.g., negative thermal expansion coefficients). The third approach concerns the dynamic probabilistic risk analysis of TPS l elements with complex characterizations for damages using a physical model of TPS system and a predictable level of ionizing radiation and space weather. Focusing is given mainly on the TPS model, mathematical models for dynamic probabilistic risk assessment and software for the modeling and prediction of the influence of the free space environment. The probabilistic risk assessment method for TPS is presented considering some deterministic and stochastic factors. The last approach concerns results of experimental research of the temperature distribution on the surface of the honeycomb sandwich panel size 150 x 150 x 20 mm at the diffusion welding in vacuum are considered. An equipment, which provides alignment of temperature fields in a product for the formation of equal strength of welded joints is considered. Many tasks in computational materials science can be posed as optimization problems. This technique enables one to find unexpected microstructures with exotic behavior (e.g., negative thermal expansion coefficients). The last approach is concerned with the generation of realizations of materials with specified but limited microstructural information: an intriguing inverse problem of both fundamental and practical importance. Computational models based upon the theories of molecular dynamics or quantum mechanics would enable the prediction and modification of fundamental materials properties. This problem is solved using deterministic and stochastic optimization techniques. The main optimization approaches in the frame of the EU project "Superlight-weight thermal protection system for space application" are discussed. Optimization approach to the alloys for obtaining materials with required properties using modeling techniques and experimental data will be also considered. This report is supported by the EU project "Superlight-weight thermal protection system for space application (LIGHT-TPS)"

The RIB facility EXOTIC and its experimental program at INFN-LNL

NASA Astrophysics Data System (ADS)

Parascandolo, Concetta

2018-05-01

In this contribution, I will present a review about the EXOTIC facility and the research field accessible by using its Radioactive Ion Beams. The EXOTIC facility, installed at the INFN-Laboratori Nazionali di Legnaro, is devoted to the in-flight production of light Radioactive Ion Beams in the energy range between 3-5 MeV/nucleon. The scientific activity performed at EXOTIC concerns different aspects of nuclear physics and nuclear astrophysics, such as, the investigation of reaction mechanisms and nuclear structure, resonant scattering experiments and measurements of nuclear reaction cross sections of astrophysical interest.

Overview of Drug Delivery Methods in Exotics, Including Their Anatomic and Physiologic Considerations.

PubMed

Coutant, Thomas; Vergneau-Grosset, Claire; Langlois, Isabelle

2018-05-01

Drug delivery to exotic animals may be extrapolated from domestic animals, but some physiologic and anatomic differences complicate treatment administration. Knowing these differences enables one to choose optimal routes for drug delivery. This review provides practitioners with a detailed review of the currently reported methods used for drug delivery of various medications in the most common exotic animal species. Exotic animal peculiarities that are relevant for drug administration are discussed in the text and outlined in tables and boxes to help the reader easily find targeted information. Copyright © 2018 Elsevier Inc. All rights reserved.

Ecological Investigations of the Federally Endangered Shivwits Milk-Vetch (Astragalus ampullarioides)--2006 Annual Report

USGS Publications Warehouse

Miller, Mark E.; Mann, Rebecca K.; Goldstein, Harland L.; Yount, James D.

2007-01-01

Astragalus ampullarioides (Welsh) Welsh, the Shivwits milk-vetch, is an herbaceous perennial legume that was listed as federally endangered in September 2001. Known populations of this edaphic endemic species are restricted to Washington County, Utah, with the majority of occurrences found on gently sloping outcrops of the Triassic Petrified Forest Member of the Chinle Formation at the edge of the Mojave Desert. At the time of listing in 2001, surveys estimated a total of 1000 individuals for the species. In April-May 2006, surveys estimated approximately 4205 individuals distributed among six populations. Of the total number of individuals estimated in spring 2006, over 75 percent were distributed among three subpopulations in Zion National Park and approximately 60 percent occurred at a single 0.3-ha site in the Park. In addition to small population sizes and limited geographic distributions, the species is threatened to varying degrees by urbanization, livestock grazing, off-road vehicle use, and invasive exotic plants. In April 2006, the U.S. Geological Survey (USGS) initiated ecological investigations of the Shivwits milk-vetch to support conservation management and recovery of the species by the National Park Service (NPS; Zion National Park), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), the Shivwits Band of the Paiute Tribe, and other cooperators such as The Nature Conservancy of Utah (TNC). To date, funding for this research has been provided by the Southwest Biological Science Center of the USGS Biological Resources Discipline, the USGS-NPS Park-Oriented Biological Support Project, and the Earth Surface Dynamics Program of the USGS Geologic Discipline. Additional logistical support has been provided by the Bureau of Land Management, Grand Staircase-Escalante National Monument. General objectives of this research are (1) to develop a better understanding of species-environment relations to support habitat modelling, future surveys for additional recovery populations, and potential efforts to establish new recovery populations; and (2) to evaluate effects of invasive exotic plants on habitat conditions and measures of milk-vetch performance. Specific objectives are to: Describe the distribution and abundance of milk-vetch populations and associated invasive exotic plant species within and outside of Zion National Park (Zion NP) in relation to geologic / geomorphic setting, soil properties, and plant community composition. In a field setting in Zion NP, conduct experiments to evaluate effects of invasive exotic plants on reproductive output and seedling establishment of A. ampullarioides across a gradient of exotic species biomass. Conduct greenhouse studies and analyze soils to evaluate effects of invasive exotic plants on soil biological properties (including mycorrhizal inocculation potential) that affect cycling and plant uptake of essential mineral nutrients. Based on environmental characteristics of known population locations, use Geographic Information System (GIS) tools to prepare a predictive habitat model that can be used to guide future surveys and efforts to evaluate sites for reintroduction efforts. This report describes 2006 progress and future plans for achieving these four objectives.

The invasiveness of Hypochaeris glabra (Asteraceae): Responses in morphological and reproductive traits for exotic populations.

PubMed

Martín-Forés, Irene; Acosta-Gallo, Belén; Castro, Isabel; de Miguel, José M; Del Pozo, Alejandro; Casado, Miguel A

2018-01-01

Scientists have been interested in many topics driven by biological invasions, such as shifts in the area of distribution of plant species and rapid evolution. Invasiveness of exotic plant species depends on variations on morphological and reproductive traits potentially associated with reproductive fitness and dispersal ability, which are expected to undergo changes during the invasion process. Numerous Asteraceae are invasive and display dimorphic fruits, resulting in a bet-hedging dispersal strategy -wind-dispersed fruits versus animal-dispersed fruits-. We explored phenotypic differentiation in seed morphology and reproductive traits of exotic (Chilean) and native (Spanish) populations of Hypochaeris glabra. We collected flower heads from five Spanish and five Chilean populations along rainfall gradients in both countries. We planted seeds from the ten populations in a common garden trial within the exotic range to explore their performance depending on the country of origin (native or exotic) and the environmental conditions at population origin (precipitation and nutrient availability). We scored plant biomass, reproductive traits and fruit dimorphism patterns. We observed a combination of bet-hedging strategy together with phenotypic differentiation. Native populations relied more on bet-hedging while exotic populations always displayed greater proportion of wind-dispersed fruits than native ones. This pattern may reflect a strategy that might entail a more efficient long distance dispersal of H. glabra seeds in the exotic range, which in turn can enhance the invasiveness of this species.

Pathways to exotic metastable silicon allotropes

DOE PAGES

Haberl, Bianca; Strobel, Timothy A.; Bradby, Jodie E.

2016-09-27

The Group 14 element silicon possesses a complex free-energy landscape with many (local) minima, allowing for the formation of a variety of unusual structures, some of which may be stabilized at ambient conditions. Such exotic silicon allotropes represent a significant opportunity to address the ever-increasing demand for novel materials with tailored functionality since these exotic forms are expected to exhibit superlative properties including optimized band gaps for solar power conversion. The application of pressure is a well-recognized and uniquely powerful method to access exotic states of silicon since it promotes large changes to atomic bonding. Conventional high-pressure syntheses, however, lackmore » the capability to access many of these local minima and only four forms of exotic silicon allotropes have been recovered over the last 50 years. However, more recently, signifi- cant advances in high pressure methodologies and the use of novel precursor materials have yielded at least three more recoverable exotic Si structures. This review aims to give an overview of these innovative methods of high-pressure application and precursor selection and the recent discoveries of new Si allotropes. The background context of the conventional pressure methods and multitude of predicted new phases are also provided. Furthermore, this review also offers a perspective for possible access to many further exotic functional allotropes not only of silicon but also of other materials, in a technologically feasible manner« less

Effects of exotic species on Yellowstone's grizzly bears

USGS Publications Warehouse

Reinhart, Daniel P.; Haroldson, Mark A.; Mattson, D.J.; Gunther, Kerry A.

2001-01-01

Humans have affected grizzly bears (Ursus arctos horribilis) by direct mortality, competition for space and resources, and introduction of exotic species. Exotic organisms that have affected grizzly bears in the Greater Yellowstone Area include common dandelion (Taraxacum officinale), nonnative clovers (Trifolium spp.), domesticated livestock, bovine brucellosis (Brucella abortus), lake trout (Salvelinus namaycush), and white pine blister rust (Cronartium ribicola). Some bears consume substantial amounts of dandelion and clover. However, these exotic foods provide little digested energy compared to higher-quality bear foods. Domestic livestock are of greater energetic value, but use of this food by bears often leads to conflicts with humans and subsequent increases in bear mortality. Lake trout, blister rust, and brucellosis diminish grizzly bears foods. Lake trout prey on native cutthroat trout (Oncorhynchus clarkii) in Yellowstone Lake; white pine blister rust has the potential to destroy native whitebark pine (Pinus albicaulis) stands; and management response to bovine brucellosis, a disease found in the Yellowstone bison (Bison bison) and elk (Cervus elaphus), could reduce populations of these 2 species. Exotic species will likely cause more harm than good for Yellowstone grizzly bears. Managers have few options to mitigate or contain the impacts of exotics on Yellowstone's grizzly bears. Moreover, their potential negative impacts have only begun to unfold. Exotic species may lead to the loss of substantial highquality grizzly bear foods, including much of the bison, trout, and pine seeds that Yellowstone grizzly bears currently depend upon.

Individual Movement Strategies Revealed through Novel Clustering of Emergent Movement Patterns

NASA Astrophysics Data System (ADS)

Valle, Denis; Cvetojevic, Sreten; Robertson, Ellen P.; Reichert, Brian E.; Hochmair, Hartwig H.; Fletcher, Robert J.

2017-03-01

Understanding movement is critical in several disciplines but analysis methods often neglect key information by adopting each location as sampling unit, rather than each individual. We introduce a novel statistical method that, by focusing on individuals, enables better identification of temporal dynamics of connectivity, traits of individuals that explain emergent movement patterns, and sites that play a critical role in connecting subpopulations. We apply this method to two examples that span movement networks that vary considerably in size and questions: movements of an endangered raptor, the snail kite (Rostrhamus sociabilis plumbeus), and human movement in Florida inferred from Twitter. For snail kites, our method reveals substantial differences in movement strategies for different bird cohorts and temporal changes in connectivity driven by the invasion of an exotic food resource, illustrating the challenge of identifying critical connectivity sites for conservation in the presence of global change. For human movement, our method is able to reliably determine the origin of Florida visitors and identify distinct movement patterns within Florida for visitors from different places, providing near real-time information on the spatial and temporal patterns of tourists. These results emphasize the need to integrate individual variation to generate new insights when modeling movement data.

Exotic diseases of dogs and cats at risk of importation to Ireland

PubMed Central

2005-01-01

Changes in legislation that facilitate movement of companion animals within the European Union will expose those animals to microbial and parasitic organisms currently exotic to Ireland. This paper reviewed information on the exotic diseases most likely to be introduced to Ireland by travelling dogs and cats: rabies, leishmaniosis, babesiosis, ehrlichiosis, anaplasmosis and dirofilariosis. PMID:21851670

Cross-Attraction between an Exotic and a Native Pine Bark Beetle: A Novel Invasion Mechanism?.

Treesearch

Min Lu; Daniel Miller; Jiang-Hua Sun

2007-01-01

Aside from the ecological impacts, invasive species fascinate ecologists because of the unique opportunities that invasives offer in the study of community ecology. Some hypotheses have been proposed to illustrate the mechanisms that allow exotics to become invasive. However, positive interactions between exotic and native insects are rarely utilized to explain...

Cross-attraction between an exotic and a native pine bark beetle: a novel invasion mechanism?

Treesearch

Min Lu; Daniel R. Miller; Jiang-Hua Sun

2007-01-01

Aside from the ecological impacts, invasive species fascinate ecologists because of the unique opportunities that invasives offer in the study of community ecology. Some hypotheses have been proposed to illustrate the mechanisms that allow exotics to become invasive. However, positive interactions between exotic and native insects are rarely utilized to explain...

Invasion of an exotic forb impacts reproductive success and site fidelity of a migratory songbird

Treesearch

Yvette Katina Ortega; Kevin Scot McKelvey; Diana Lee Six

2006-01-01

Although exotic plant invasions threaten natural systems worldwide, we know little about the specific ecological impacts of invaders, including the magnitude of effects and underlying mechanisms. Exotic plants are likely to impact higher trophic levels when they overrun native plant communities, affecting habitat quality for breeding songbirds by altering food...

Effects of biological control agents and exotic plant invasion on deer mouse populations

Treesearch

Yvette K. Ortega; Dean E. Pearson; Kevin S. McKelvey

2004-01-01

Exotic insects are commonly introduced as biological control agents to reduce densities of invasive exotic plants. Although current biocontrol programs for weeds take precautions to minimize ecological risks, little attention is paid to the potential nontarget effects of introduced food subsidies on native consumers. Previous research demonstrated that two gall flies (...

Remote analysis of biological invasion and the impact of enemy release

Treesearch

James R. Kellner; Gregory P. Asner; Kealoha M. Kinney; Scott R. Loarie; David E. Knapp; Ty Kennedy-Bowdoin; Erin J. Questad; Susan Cordell; Jarrod M. Thaxton

2011-01-01

Escape from natural enemies is a widely held generalization for the success of exotic plants. We conducted a large-scale experiment in Hawaii (USA) to quantify impacts of ungulate removal on plant growth and performance, and to test whether elimination of an exotic generalist herbivore facilitated exotic success. Assessment of impacted and control sites before and...

"FruitZotic": A Sensory Approach to Introducing Preschoolers to Fresh Exotic Fruits at Head Start Locations in Western Massachusetts

ERIC Educational Resources Information Center

Kannan, Srimathi; Smith, Rebecca; Foley, Christine; Del Sole, Sarah; White, Alissa; Sheldon, Lisa A.; Mietlcki-Floyd, Shirley; Severin, Suzanne

2011-01-01

FruitZotic incorporated fruit stories (exotic-fruits-literacy), a "See, Smell, Hear, Touch and Taste" (sensory) segment and a question-prompted discussion. Three take-home components incorporating the exotic fruits were: Coloring Activity, Recipes, and Fact Sheets. Sensory based nutrition education can increase familiarity with exotic…

PROSPECTS FOR PENTAQUARK SEARCHES IN E+D- ANNIHILATIONS AND VV COLLISIONS.

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

ARMSTRONG,S.; MELLADO,B.; WU,S.L.

2004-06-28

Recent strong experimental evidence of a narrow exotic S = +1 baryon resonance, {Theta}{sup +}, suggests the existence of other exotic baryons. We discuss the prospects of confirming earlier experimental evidence of {Theta}{sup +} and the observation of additional hypothetical exotic baryons in e{sup +}e{sup -} annihilations and {gamma}{gamma} collisions at LEP and B Factories.

Nest site selection in native and exotic trees by Black-chinned Hummingbirds

Treesearch

Deborah M. Finch; Jeffrey Kelly

2002-01-01

We studied nest site selection and nesting success in Black-chinned Hummingbirds (Archilochus alexandri) along the middle Rio Grande, New Mexico. The study was conducted in association with an exotic woody plant removal program to determine whether the removal of exotic plants would affect wildlife populations and nesting success, either positively or negatively. Point...

Loblolly pine seedling response to competition from exotic vs. native plants

Treesearch

Pedram Daneshgar; Shibu Jose; Craig Ramsey; Robin Collins

2006-01-01

A field study was conducted in Santa Rosa County, FL to test the hypothesis that an exotic understory would exert a higher degree of competition on tree seedling establishment and growth than native vegetation. The study site was a 60 ha cutover area infested with the invasive exotic cogongrass [Imperata cylindrica (L.) Raeusch.]. A completely...

Exotic cheatgrass and loss of soil biota decrease the performance of a native grass

Treesearch

Suzanne M. Owen; Carolyn Hull Sieg; Nancy Collins Johnson; Catherine A. Gehring

2013-01-01

Soil disturbances can alter microbial communities including arbuscular mycorrhizal (AM) fungi, which may in turn, affect plant community structure and the abundance of exotic species. We hypothesized that altered soil microbial populations owing to disturbance would contribute to invasion by cheatgrass (Bromus tectorum), an exotic annual grass, at the expense of the...

Diseases of Forest Trees: Consequences of Exotic Ecosystems?

Treesearch

William J. Otrosina

1998-01-01

Much attention is now given to risks and impacts of exotic pest introductions in forest ecosystems. This concern is for good reason because, once introduced, an exotic pathogen or insect encounters little resistance in the native plant population and can produce catastrophic losses in relatively short periods of time. Most native fungal pathogens of forest trees have...

Naturalized Exotic Tree Species in Puerto Rico

Treesearch

John K. Francis; Henri A. Liogier

1991-01-01

Many exotic tree species have been imported into Puerto Rico for their wood, fruit, and use as coffee shade and ornamentals. Some of these trees have naturalized (reproduced without human intervention) and some have escaped into natural forests. At least 118 exotic species are reproducing in Puerto Rico. Estimates are given for the general rate of spread and future...

A survey of exotic plants in federal wilderness areas

Treesearch

Marilyn Marler

2000-01-01

I conducted a survey of wilderness areas to provide an overview of plant invasions in the National Wilderness Preservation System. Fifteen per cent of responding mangers reported that exotic plants were among their top 10 management concerns, either because they are actively dealing with control of exotic pest plants or have prioritized prevention of their...

The role of tensor force in heavy-ion fusion dynamics

NASA Astrophysics Data System (ADS)

Guo, Lu; Simenel, Cédric; Shi, Long; Yu, Chong

2018-07-01

The tensor force is implemented into the time-dependent Hartree-Fock (TDHF) theory so that both exotic and stable collision partners, as well as their dynamics in heavy-ion fusion, can be described microscopically. The role of tensor force on fusion dynamics is systematically investigated for 40Ca +40Ca , 40Ca +48Ca , 48Ca +48Ca , 48Ca +56Ni , and 56Ni +56Ni reactions which vary by the total number of spin-unsaturated magic numbers in target and projectile. A notable effect on fusion barriers and cross sections is observed by the inclusion of tensor force. The origin of this effect is analyzed. The influence of isoscalar and isovector tensor terms is investigated with the TIJ forces. These effects of tensor force in fusion dynamics are essentially attributed to the shift of low-lying vibration states of colliding partners and nucleon transfer in the asymmetric reactions. Our calculations of above-barrier fusion cross sections also show that tensor force does not significantly affect the dynamical dissipation at near-barrier energies.

Baryons as Fock states of 3,5,... Quarks

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

Dmitri Diakonov; Victor Petrov

2004-09-01

We present a generating functional producing quark wave functions of all Fock states in the octet, decuplet and antidecuplet baryons in the mean field approximation, both in the rest and infinite momentum frames. In particular, for the usual octet and decuplet baryons we get the SU(6)-symmetric wave functions for their 3-quark component but with specific corrections from relativism and from additional quark-antiquark pairs. For the exotic antidecuplet baryons we obtain the 5-quark wave function.

Dynamics of thin-shell wormholes with different cosmological models

NASA Astrophysics Data System (ADS)

Sharif, Muhammad; Mumtaz, Saadia

This work is devoted to investigate the stability of thin-shell wormholes in Einstein-Hoffmann-Born-Infeld electrodynamics. We also study the attractive and repulsive characteristics of these configurations. A general equation-of-state is considered in the form of linear perturbation which explores the stability of the respective wormhole solutions. We assume Chaplygin, linear and logarithmic gas models to study exotic matter at thin-shell and evaluate stability regions for different values of the involved parameters. It is concluded that the Hoffmann-Born-Infeld parameter and electric charge enhance the stability regions.

An Exotic Species Is the Favorite Prey of a Native Enemy

PubMed Central

Li, Yiming; Ke, Zunwei; Wang, Supen; Smith, Geoffrey R.; Liu, Xuan

2011-01-01

Although native enemies in an exotic species' new range are considered to affect its ability to invade, few studies have evaluated predation pressures from native enemies on exotic species in their new range. The exotic prey naiveté hypothesis (EPNH) states that exotic species may be at a disadvantage because of its naïveté towards native enemies and, therefore, may suffer higher predation pressures from the enemy than native prey species. Corollaries of this hypothesis include the native enemy preferring exotic species over native species and the diet of the enemy being influenced by the abundance of the exotic species. We comprehensively tested this hypothesis using introduced North American bullfrogs (Lithobates catesbeianus, referred to as bullfrog), a native red-banded snake (Dinodon rufozonatum, the enemy) and four native anuran species in permanent still water bodies as a model system in Daishan, China. We investigated reciprocal recognition between snakes and anuran species (bullfrogs and three common native species) and the diet preference of the snakes for bullfrogs and the three species in laboratory experiments, and the diet preference and bullfrog density in the wild. Bullfrogs are naive to the snakes, but the native anurans are not. However, the snakes can identify bullfrogs as prey, and in fact, prefer bullfrogs over the native anurans in manipulative experiments with and without a control for body size and in the wild, indicating that bullfrogs are subjected to higher predation pressures from the snakes than the native species. The proportion of bullfrogs in the snakes' diet is positively correlated with the abundance of bullfrogs in the wild. Our results provide strong evidence for the EPNH. The results highlight the biological resistance of native enemies to naïve exotic species. PMID:21915306

The relative importance of disturbance and exotic-plant abundance in California coastal sage scrub

USGS Publications Warehouse

Fleming, G.M.; Diffendorfer, J.E.; Zedler, P.H.

2009-01-01

Many ecosystems of conservation concern require some level of disturbance to sustain their species composition and ecological function. However, inappropriate disturbance regimes could favor invasion or expansion of exotic species. In southern California coastal sage scrub (CSS) fire is a natural disturbance, but because of human influence, frequencies may now be unnaturally high. Other anthropogenic disturbances such as grazing also occur in reserve areas. Managers charged with imposing or tolerating fire or other disturbance within their reserves are concerned that habitat quality may be degraded by an increasing abundance of exotic plants. We used vegetation monitoring data from Camp Pendleton, California, USA, to assess the correlation between past disturbances (frequent fire, agriculture, or grazing and mechanical disturbances) and current exotic species abundance in CSS. We found that disturbance history was only modestly related to exotic abundance overall, but fire frequency showed the strongest association. We also examined whether cover and richness of various native plant life forms (woody species, perennial herbs, and annual herbs) were more strongly influenced by disturbance history or by exotic-plant abundance. Native plant responses varied among life forms, but woody species and annual herbs were generally more strongly and negatively associated with exotic abundance than with disturbance. Effective CSS conservation will require developing means to curb the negative impacts of exotic plants, which may abound with or without severe or recent disturbance. Additionally, more focus should be given to understory herbs showing sensitivity to invasion. Though understudied, native herbs comprise the greatest portion of plant diversity in CSS and are critical to preservation of the community as a whole. ?? 2009 by the Ecological Society of America.

Overview of the Distribution, Habitat Association and Impact of Exotic Ants on Native Ant Communities in New Caledonia

PubMed Central

Berman, Maïa; Andersen, Alan N.; Hély, Christelle; Gaucherel, Cédric

2013-01-01

Ants are among the most ubiquitous and harmful invaders worldwide, but there are few regional studies of their relationships with habitat and native ant communities. New Caledonia has a unique and diverse ant fauna that is threatened by exotic ants, but broad-scale patterns of exotic and native ant community composition in relation to habitat remain poorly documented. We conducted a systematic baiting survey of 56 sites representing the main New Caledonian habitat types: rainforest on ultramafic soils (15 sites), rainforest on volcano-sedimentary soils (13), maquis shrubland (15), Melaleuca-dominated savannas (11) and Acacia spirorbis thickets (2). We collected a total of 49 species, 13 of which were exotic. Only five sites were free of exotic species, and these were all rainforest. The five most abundant exotic species differed in their habitat association, with Pheidole megacephala associated with rainforests, Brachymyrmex cf. obscurior with savanna, and Wasmannia auropunctata and Nylanderia vaga present in most habitats. Anoplolepis gracilipes occurred primarily in maquis-shrubland, which contrasts with its rainforest affinity elsewhere. Multivariate analysis of overall ant species composition showed strong differentiation of sites according to the distribution of exotic species, and these patterns were maintained at the genus and functional group levels. Native ant composition differed at invaded versus uninvaded rainforest sites, in the absence of differences in habitat variables. Generalised Myrmicinae and Forest Opportunists were particularly affected by invasion. There was a strong negative relationship between the abundance of W. auropunctata and native ant abundance and richness. This emphasizes that, in addition to dominating many ant communities numerically, some exotic species, and in particular W. auropunctata, have a marked impact on native ant communities. PMID:23840639

Biodiversity Loss following the Introduction of Exotic Competitors: Does Intraguild Predation Explain the Decline of Native Lady Beetles?

PubMed Central

Smith, Chelsea A.; Gardiner, Mary M.

2013-01-01

Exotic species are widely accepted as a leading cause of biodiversity decline. Lady beetles (Coccinellidae) provide an important model to study how competitor introductions impact native communities since several native coccinellids have experienced declines that coincide with the establishment and spread of exotic coccinellids. This study tested the central hypothesis that intraguild predation by exotic species has caused these declines. Using sentinel egg experiments, we quantified the extent of predation on previously-common (Hippodamia convergens) and common (Coleomegilla maculata) native coccinellid eggs versus exotic coccinellid (Harmonia axyridis) eggs in three habitats: semi-natural grassland, alfalfa, and soybean. Following the experiments quantifying egg predation, we used video surveillance to determine the composition of the predator community attacking the eggs. The extent of predation varied across habitats, and egg species. Native coccinellids often sustained greater egg predation than H. axyridis. We found no evidence that exotic coccinellids consumed coccinellid eggs in the field. Harvestmen and slugs were responsible for the greatest proportion of attacks. This research challenges the widely-accepted hypothesis that intraguild predation by exotic competitors explains the loss of native coccinellids. Although exotic coccinellids may not be a direct competitor, reduced egg predation could indirectly confer a competitive advantage to these species. A lower proportion of H. axyridis eggs removed by predators may have aided its expansion and population increase and could indirectly affect native species via exploitative or apparent competition. These results do not support the intraguild predation hypothesis for native coccinellid decline, but do bring to light the existence of complex interactions between coccinellids and the guild of generalist predators in coccinellid foraging habitats. PMID:24386383

An exotic species is the favorite prey of a native enemy.

PubMed

Li, Yiming; Ke, Zunwei; Wang, Supen; Smith, Geoffrey R; Liu, Xuan

2011-01-01

Although native enemies in an exotic species' new range are considered to affect its ability to invade, few studies have evaluated predation pressures from native enemies on exotic species in their new range. The exotic prey naiveté hypothesis (EPNH) states that exotic species may be at a disadvantage because of its naïveté towards native enemies and, therefore, may suffer higher predation pressures from the enemy than native prey species. Corollaries of this hypothesis include the native enemy preferring exotic species over native species and the diet of the enemy being influenced by the abundance of the exotic species. We comprehensively tested this hypothesis using introduced North American bullfrogs (Lithobates catesbeianus, referred to as bullfrog), a native red-banded snake (Dinodon rufozonatum, the enemy) and four native anuran species in permanent still water bodies as a model system in Daishan, China. We investigated reciprocal recognition between snakes and anuran species (bullfrogs and three common native species) and the diet preference of the snakes for bullfrogs and the three species in laboratory experiments, and the diet preference and bullfrog density in the wild. Bullfrogs are naive to the snakes, but the native anurans are not. However, the snakes can identify bullfrogs as prey, and in fact, prefer bullfrogs over the native anurans in manipulative experiments with and without a control for body size and in the wild, indicating that bullfrogs are subjected to higher predation pressures from the snakes than the native species. The proportion of bullfrogs in the snakes' diet is positively correlated with the abundance of bullfrogs in the wild. Our results provide strong evidence for the EPNH. The results highlight the biological resistance of native enemies to naïve exotic species.

The extended BLMSSM with a 125 GeV Higgs boson and dark matter

NASA Astrophysics Data System (ADS)

Zhao, Shu-Min; Feng, Tai-Fu; Ning, Guo-Zhu; Chen, Jian-Bin; Zhang, Hai-Bin; Dong, Xing Xing

2018-04-01

To extend the BLMSSM, we not only add exotic Higgs superfields (Φ _{NL},φ_{NL}) to make the exotic lepton heavy, but also introduce the superfields ( Y,Y^' ) having couplings with lepton and exotic lepton at tree level. The obtained model is called as EBLMSSM, which has difference from BLMSSM especially for the exotic slepton (lepton) and exotic sneutrino (neutrino). We deduce the mass matrices and the needed couplings in this model. To confine the parameter space, the Higgs boson mass m_{h^0} and the processes h^0→ γ γ , h^0→ VV, V=(Z,W) are studied in the EBLMSSM. With the assumed parameter space, we obtain reasonable numerical results according to data on Higgs from ATLAS and CMS. As a cold dark mater candidate, the relic density for the lightest mass eigenstate of Y and Y' mixing is also studied.

Exotic grasslands on reclaimed midwestern coal mines: An ornithological perspective

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

Scott, P.E.; Lima, S.L.

The largest grasslands in Indiana and Illinois are on reclaimed surface coal mines, which are numerous in the Illinois Coal Basin. The reclamation goal of establishing a vegetation cover with inexpensive, hardy exotic grass species (e.g., tall fescue, smooth brome) inadvertently created persistent, large grassland bird refuges. We review research documenting the importance of these sites for native prairie birds. On mines, grassland specialist birds (restricted to grassland throughout their range) prefer sites dominated by exotic grasses to those rich in forbs, whereas nonspecialist bird species show no significant preference. Midwestern mine grasslands potentially could be converted into landscapes thatmore » include native warm-season grasses and forbs adapted to the relatively dry, poor soil conditions, in addition to the present successful exotic grass stands. A key question is whether native mixtures will resist conversion to forb-rich or woody growth over the long term, as the exotic grasses have done.« less

Plant recruitment and soil microbial characteristics of rehabilitation seedings following wildfire in northern Utah

Treesearch

Megan M. Taylor; Ann L. Hild; Nancy L. Shaw; Urszula Norton; Timothy R. Collier

2014-01-01

One goal of post-fire native species seeding is to increase plant community resistance to exotic weed invasions, yet few studies address the impacts of seeding on exotic annual establishment and persistence. In 2010 and 2011, we investigated the influence of seedings on exotic annuals and the underlying microbial communities. The wildfire site in northern Utah was...

Risk maps for targeting exotic plant pest detection programs in the United States

Treesearch

R.D. Magarey; D.M. Borchert; J.S. Engle; M Garcia-Colunga; Frank H. Koch; et al

2011-01-01

In the United States, pest risk maps are used by the Cooperative Agricultural Pest Survey for spatial and temporal targeting of exotic plant pest detection programs. Methods are described to create standardized host distribution, climate and pathway risk maps for the top nationally ranked exotic pest targets. Two examples are provided to illustrate the risk mapping...

Domestic exotics and the perception of invasibility

Treesearch

Qinfeng Guo; Robert Ricklefs

2010-01-01

Susceptibility of an area to invasion by exotic species is often judged by the fraction of introduced species in the local biota. However, the degree of invasion, particularly in mainland areas, has often been underestimated because of the exclusion of ‘domestic exotics’ (those introduced to internal units from within the national border) in calculations. Because all...

Temporal changes in native-exotic richness correlations during early post-fire succession

Treesearch

Qinfeng Guo

2017-01-01

The relationship between native and exotic richness has mostly been studied with respect to space (i.e., positive at larger scales, but negative or more variable at smaller scales) and its temporal patterns have rarely been investigated. Although some studies have monitored the temporal trends of both native and exotic richness, how these two groups of species might be...

Detection of Tetropium castaneum L., an exotic longhorned beetle in the Dalles, Oregon

Treesearch

Kathleen J.R. Johnson; Alan D. Mudge; James R. LaBonte; Karl A. Puls

2003-01-01

Concerns about the unintentional introduction of exotic woodboring insects prompted surveys of high-risk sites in Oregon beginning in 1997. Ports, port areas, mills and businesses known to have received imported wood or wood products and urban forests have been monitored statewide. These surveys have produced new state and regional records for exotic woodborers (Mudge...

Prudent Use of Antimicrobials in Exotic Animal Medicine.

PubMed

Broens, Els M; van Geijlswijk, Ingeborg M

2018-05-01

Reduction of antimicrobial use can result in reduction of resistance in commensal bacteria. In exotic animals, information on use of antimicrobials and resistance in commensals and pathogens is scarce. However, use of antimicrobials listed as critically important antimicrobials for human medicine seems high in exotic animals. Ideally, the selection of a therapy should be based on an accurate diagnosis and antimicrobial susceptibility testing. When prescribing antimicrobials based on empiricism, knowledge of the most common pathogens causing specific infections and the antimicrobial spectrum of antimicrobial agents is indispensable. Implementing antimicrobial stewardship promotes the prudent use of antimicrobials in exotic animals. Copyright © 2018 Elsevier Inc. All rights reserved.

Therapeutic Contraindications in Exotic Pets.

PubMed

Petritz, Olivia A; Chen, Sue

2018-05-01

The selection and dosing of medications for exotic pets are often challenging because most drugs are used in an extralabel manner without pharmacokinetic and pharmacodynamic studies. Doses are often extrapolated from common domestic animals and safety data are often lacking in exotic species. Just as the bioavailability and therapeutic levels are different for each species, what may be a safe and commonly used medication in one species can be deadly in another. Various drugs with documented contraindications in certain exotic pet species are outlined in this review and the pathophysiology, clinical signs, and treatment options are described when applicable. Copyright © 2018 Elsevier Inc. All rights reserved.

Changes in Trace Gas Nitrogen Emissions as a Response to Ecosystem Type Conversion in a Semi-Arid Climate.

NASA Astrophysics Data System (ADS)

Andrews, H.; Eberwein, J. R.; Jenerette, D.

2016-12-01

As humans continue to introduce exotic plants and to alter climate and fire regimes in semi-arid ecosystems, many plant communities have begun to shift from perennial forbs and shrubs to annual grasses with different functional traits. Shifts in plant types are also associated with shifts in microclimate, microbial activity, and litter inputs, all of which contribute to the efficiency of nitrogen processing and the magnitude of trace gas emissions (NOx and N2O), which are increasingly important fluxes in water-limited systems. Here, we explored how changes in plant litter impact trace gas emissions, asking the question: How does conversion from a native shrubland to exotic grassland ecosystem alter NOx and N2O fluxes in a semi-arid climate? We posed two hypotheses to explain the impacts of different types of litter on soils disturbed by exotic grasses and those that were still considered shrublands: 1.) Soils that have undergone conversion by exotic grasses release higher amounts of NOx and N2O than do those of unconverted shrublands, due to disruptions of native plant and soil processes by exotic grasses, and 2.) Because litter of exotic grasses has lower C:N than that of shrubs, litter inputs from exotic grasses will increase NOx and N2O emissions from soils more than will litter inputs from shrubs. As a preliminary study, we experimentally wetted mesocosms in a laboratory incubation containing converted and unconverted soils that had been mixed with no litter or either exotic grass or coastal sage scrub (CSS) litter. We measured N2O fluxes from mesocosms over a 48-hour period. 24 hours after wetting, samples with grass litter produced higher amounts of N2O than those with CSS litter; similarly, converted soils produced higher amounts of N2O than unconverted soils. These two effects combined resulted in exotic grassland conditions (converted soils with exotic grass litter) producing 10 times the amount of N2O as those containing native shrubland conditions (unconverted soils with CSS litter). Additionally, soils with no litter peaked in N2O emissions earlier than those with litter (12 hours after wetting compared to 24 hours after wetting). Following preliminary results, we suggest that differences in plant traits, such as litter, play a significant role in the magnitude and timing of trace gas nitrogen emissions.

Ultrafast nonthermal heating of water initiated by an X-ray Free-Electron Laser.

PubMed

Beyerlein, Kenneth R; Jönsson, H Olof; Alonso-Mori, Roberto; Aquila, Andrew; Bajt, Saša; Barty, Anton; Bean, Richard; Koglin, Jason E; Messerschmidt, Marc; Ragazzon, Davide; Sokaras, Dimosthenis; Williams, Garth J; Hau-Riege, Stefan; Boutet, Sébastien; Chapman, Henry N; Tîmneanu, Nicuşor; Caleman, Carl

2018-05-29

The bright ultrafast pulses of X-ray Free-Electron Lasers allow investigation into the structure of matter under extreme conditions. We have used single pulses to ionize and probe water as it undergoes a phase transition from liquid to plasma. We report changes in the structure of liquid water on a femtosecond time scale when irradiated by single 6.86 keV X-ray pulses of more than 10 6 J/cm 2 These observations are supported by simulations based on molecular dynamics and plasma dynamics of a water system that is rapidly ionized and driven out of equilibrium. This exotic ionic and disordered state with the density of a liquid is suggested to be structurally different from a neutral thermally disordered state.

The majority of bold statements expressed during grand rounds lack scientific merit.

PubMed

Linthorst, Gabor E; Daniels, Johannes M A; van Westerloo, David J

2007-10-01

Frequently, during grand rounds and other medical conferences, bold statements are made regarding 'exotic medical facts'. Such exotic expert opinions are frequently voiced with great conviction and are usually subsequently assimilated by junior staff as medical fact. The level of scientific evidence for each exotic expert opinion expressed during daily grand rounds over a 4-month period was evaluated. If, following a short discussion of the statement, any doubt as to the merits of the claim persisted, the person who made the statement was asked to perform a search in the medical literature on the subject. In total, 25 cases of exotic expert opinion were identified during the study period. Of these, 22 statements were made by senior staff and 3 by residents. Careful review of the literature showed only 8 of the statements were actually evidence-based. In 17 cases the available literature actually contradicted the statement (n = 13) or no literature on the subject could be located (n = 4). Although opinions were most often expressed by staff members, the reviews of their merits were more often performed by residents. The vast majority of exotic expert opinions expressed by senior staff members during grand rounds are not evidence-based. Thus, great care must be taken to ensure that exotic expert opinion is not accepted as factual without careful review. Furthermore, this study shows that although seniority is (as expected) associated with a higher incidence of voicing exotic expert opinion, it is negatively associated with reviewing the merits of such opinion.

Species frequency dynamics in an old-field succession: Effects of disturbance, fertilization and scale

USGS Publications Warehouse

Gibson, D.J.; Middleton, B.A.; Foster, K.; Honu, Y.A.K.; Hoyer, E.W.; Mathis, M.

2005-01-01

Question: Can patterns of species frequency in an old-field be explained within the context of a metapopulation model? Are the patterns observed related to time, spatial scale, disturbance, and nutrient availability? Location: Upland and lowland old-fields in Illinois, USA. Method: Species richness was recorded annually for seven years following plowing of an upland and lowland old-field subject to crossed fertilizer and disturbance treatments (mowing and rototilling). Species occupancy distributions were assessed with respect to the numbers of core and satellite species. Results: In both fields, species richness became higher in disturbed plots than in undisturbed plots over time, and decreased in fertilized plots irrespective of time. A bimodal pattern of species richness consistent with the Core-satellite species (CSS) hypothesis occurred in the initial seed bank and through the course of early succession. The identity of native and exotic core species (those present in > 90% of blocks) changed with time. Some core species from the seed bank became core species in the vegetation, albeit after several years. At the scale of individual plots, a bimodal fit consistent with the CSS hypothesis applied only in year 1 and rarely thereafter. Conclusions: The CSS hypothesis provides a metapopulation perspective for understanding patterns of species richness but requires the assessment of spatial and temporal scaling effects. Regional processes (e.g. propagule availability) at the largest scale have the greatest impact influencing community structure during early secondary succession. Local processes (e.g., disturbance and soil nutrients) are more important at smaller scales and place constraints on species establishment and community structure of both native and exotic species. Under the highest intensity of disturbance, exotic species may be able to use resources unavailable to, or unused by, native species. ?? IAVS; Opulus Press.

Tolerance and resistance of invasive and native Eupatorium species to generalist herbivore insects

NASA Astrophysics Data System (ADS)

Wang, Rui-Fang; Feng, Yu-Long

2016-11-01

Invasive plants are exotic species that escape control by native specialist enemies. However, exotic plants may still be attacked by locally occurring generalist enemies, which can influence the dynamics of biological invasions. If invasive plants have greater defensive (resistance and tolerance) capabilities than indigenous plants, they may experience less damage from native herbivores. In the present study, we tested this prediction using the invasive plant Eupatorium adenophorum and two native congeners under simulated defoliation and generalist herbivore insect (Helicoverpa armigera and Spodoptera litura) treatments. E. adenophorum was less susceptible and compensated more quickly to damages in biomass production from both treatments compared to its two congeners, exhibiting greater herbivore tolerance. This strong tolerance to damage was associated with greater resource allocation to aboveground structures, leading to a higher leaf area ratio and a lower root: crown mass ratio than those of its native congeners. E. adenophorum also displayed a higher resistance index (which integrates acid detergent fiber, nitrogen content, carbon/nitrogen ratio, leaf mass per area, toughness, and trichome density) than its two congeners. Thus, H. armigera and S. litura performed poorly on E. adenophorum, with less leaf damage, a lengthened insect developmental duration, and decreased pupating: molting ratios compared to those of the native congeners. Strong tolerance and resistance traits may facilitate the successful invasion of E. adenophorum in China and may decrease the efficacy of leaf-feeding biocontrol agents. Our results highlight both the need for further research on defensive traits and their role in the invasiveness and biological control of exotic plants, and suggest that biocontrol of E. adenophorum in China would require damage to the plant far in excess of current levels.

Streamflow and sediment dynamics of the Middle Rio Grande Valley, New Mexico, in the context of cottonwood recruitment

USGS Publications Warehouse

Milhous, Robert T.; Wondzell, Mark; Ritter, Amy

1993-01-01

The cottonwood gallery forests of the Middle Rio Grande floodplain in New Mexico provide important habitats for birds and other animals. Over the last century, these forests have changed significantly due to invasion of exotics such as salt cedar and Russian olive, which compete with native cottonwoods, and changes in water use both in the valley and upstream. To successfully germinate and establish, cottonwoods require an adequate water supply, abundant sunlight, and bare, litter-free substrate. Native cottonwoods are adapted to a natural snowmelt hydrograph characterized by spring floods in late May or early June and gradually receding streamflows throughout the remainder of the summer. The natural streamflow pattern has been significantly modified by water management in the Rio Grande basin. The modified pattern is less conducive to establishment of cottonwoods than the natural pattern. In addition, exotic species now compete with native cottonwoods, and the modified flow pattern may favor these exotics. The overall objective of this study was to investigate the possibility of enhancing cottonwood establishment and recruitment along the Middle Rio Grande through streamflow manipulation and reservoir releases. The work integrates concepts of cottonwood establishment, water resources management, and river morphology, and investigates how water management might be used to preserve and enhance cottonwood gallery forests along the river. Specific objectives of the work reported herein were to: (1) develop a technique to calculate flows that will produce channel characteristics necessary to restore and sustain cottonwood gallery forests; (2) develop a model to determine a flow pattern, or sequence of flows, that will improve the potential for cottonwood establishment and recruitment; and (3) determine if the water resources can be managed to produce the desired channel characteristics and flow pattern identified in (1) and (2).

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

Moon, Chang-Bum, E-mail: cbmoon@hoseo.edu

This paper outlines the new physics possibilities that fall within the field of nuclear structure and astrophysics based on experiments with radioactive ion beams at the future Rare Isotope Beams Accelerator facility in Korea. This ambitious multi-beam facility has both an Isotope Separation On Line (ISOL) and fragmentation capability to produce rare isotopes beams (RIBs) and will be capable of producing and accelerating beams of wide range mass of nuclides with energies of a few to hundreds MeV per nucleon. The large dynamic range of reaccelerated RIBs will allow the optimization in each nuclear reaction case with respect to crossmore » section and channel opening. The low energy RIBs around Coulomb barrier offer nuclear reactions such as elastic resonance scatterings, one or two particle transfers, Coulomb multiple-excitations, fusion-evaporations, and direct capture reactions for the study of the very neutron-rich and proton-rich nuclides. In contrast, the high energy RIBs produced by in-flight fragmentation with reaccelerated ions from the ISOL enable to explore the study of neutron drip lines in intermediate mass regions. The proposed studies aim at investigating the exotic nuclei near and beyond the nucleon drip lines, and to explore how nuclear many-body systems change in such extreme regions by addressing the following topics: the evolution of shell structure in areas of extreme proton to neutron imbalance; the study of the weak interaction in exotic decay schemes such as beta-delayed two-neutron or two-proton emission; the change of isospin symmetry in isobaric mirror nuclei at the drip lines; two protons or two neutrons radioactivity beyond the drip lines; the role of the continuum states including resonant states above the particle-decay threshold in exotic nuclei; and the effects of nuclear reaction rates triggered by the unbound proton-rich nuclei on nuclear astrophysical processes.« less

Reduced mycorrhizal responsiveness leads to increased competitive tolerance in an invasive exotic plant

Treesearch

Lauren P. Waller; Ragan M. Callaway; John N. Klironomos; Yvette K. Ortega; John L. Maron

2016-01-01

1. Arbuscular mycorrhizal (AM) fungi can exert a powerful influence on the outcome of plant–plant competition. Since some exotic plants interact differently with soil biota such as AM fungi in their new range, range-based shifts in AM responsiveness could shift competitive interactions between exotic and resident plants, although this remains poorly studied. 2. We...

Exotic, native and seeded species and soil biotic community response to post-fire seedings in northern Utah

Treesearch

Megan Taylor

2013-01-01

Post-fire seeding of native species is intended to reduce weed entry, yet few studies have addressed the impacts of seeding methods on the establishment and persistence of exotic annuals. In summers of 2010 and 2011, we investigated productivity of exotic annuals across rehabilitation seedings that were established on the Scooby Wildfire site in northern Utah. The site...

Soils conditioned by native vegetation and by the exotic invasive annual grass Bromus tectorum: do a native perennial and two exotic grasses sense the substrates similarly

USDA-ARS?s Scientific Manuscript database

Invasion by the exotic annual grass Bromus tectorum often increases soil nutrient availability. It is unclear, however, if other grasses benefit from this higher nutrient status. Soil from three sites in the northern Great Basin U.S.A. conditioned by B. tectoruminvasion (BTCS=B. tectorum conditioned...

Constraints on Exotic Spin-Dependent Interactions Between Matter and Antimatter from Antiprotonic Helium Spectroscopy

NASA Astrophysics Data System (ADS)

Ficek, Filip; Fadeev, Pavel; Flambaum, Victor V.; Jackson Kimball, Derek F.; Kozlov, Mikhail G.; Stadnik, Yevgeny V.; Budker, Dmitry

2018-05-01

Heretofore undiscovered spin-0 or spin-1 bosons can mediate exotic spin-dependent interactions between standard model particles. Here, we carry out the first search for semileptonic spin-dependent interactions between matter and antimatter. We compare theoretical calculations and spectroscopic measurements of the hyperfine structure of antiprotonic helium to constrain exotic spin- and velocity-dependent interactions between electrons and antiprotons.

Constraints on Exotic Spin-Dependent Interactions Between Matter and Antimatter from Antiprotonic Helium Spectroscopy.

PubMed

Ficek, Filip; Fadeev, Pavel; Flambaum, Victor V; Jackson Kimball, Derek F; Kozlov, Mikhail G; Stadnik, Yevgeny V; Budker, Dmitry

2018-05-04

Heretofore undiscovered spin-0 or spin-1 bosons can mediate exotic spin-dependent interactions between standard model particles. Here, we carry out the first search for semileptonic spin-dependent interactions between matter and antimatter. We compare theoretical calculations and spectroscopic measurements of the hyperfine structure of antiprotonic helium to constrain exotic spin- and velocity-dependent interactions between electrons and antiprotons.

FUEL CONDITIONS ASSOCIATED WITH NATIVE AND EXOTIC GRASSES IN A SUBTROPICAL DRY FOREST IN PUERTO RICO

Treesearch

Jarrod M. Thaxton; Skip J. Van Bloem; Stefanie Whitmire

2012-01-01

Exotic grasses capable of increasing frequency and intensity of anthropogenic fire have invaded subtropical and tropical dry forests worldwide. Since many dry forest trees are susceptible to fire, this can result in decline of native species and loss of forest cover. While the contribution of exotic grasses to altered fire regimes has been well documented, the role of...

Batteries for storage of wind-generated energy

NASA Technical Reports Server (NTRS)

Schwartz, H. J.

1973-01-01

Cost effectiveness characteristics of conventional-, metal gas-, and high energy alkali metal-batteries for wind generated energy storage are considered. A lead-acid battery with a power density of 20 to 30 watt/hours per pound is good for about 1500 charge-discharge cycles at a cost of about $80 per kilowatt hour. A zinc-chlorine battery that stores chlorine as solid chlorine hydrate at temperatures below 10 C eliminates the need to handle gaseous chlorine; its raw material cost are low and inexpensive carbon can be used for the chlorine electrode. This system has the best chance to replace lead-acid. Exotic alkali metal batteries are deemed too costly at the present stage of development.

Versatile generation of optical vector fields and vector beams using a non-interferometric approach.

PubMed

Tripathi, Santosh; Toussaint, Kimani C

2012-05-07

We present a versatile, non-interferometric method for generating vector fields and vector beams which can produce all the states of polarization represented on a higher-order Poincaré sphere. The versatility and non-interferometric nature of this method is expected to enable exploration of various exotic properties of vector fields and vector beams. To illustrate this, we study the propagation properties of some vector fields and find that, in general, propagation alters both their intensity and polarization distribution, and more interestingly, converts some vector fields into vector beams. In the article, we also suggest a modified Jones vector formalism to represent vector fields and vector beams.

Advanced Thermophotovoltaic Cells Modeling, Optimized for Use in Radioisotope Thermoelectric Generators (RTGs) for Mars and Deep Space Missions

DTIC Science & Technology

2004-06-01

PAGE INTENTIONALLY LEFT BLANK v ABSTRACT Thermophotovoltaic cells are a good candidate for use in high efficiency radioiso- tope...ongoing in this field since the 1950’s, but the exotic materials necessary for high efficiency cells has only been recently available. Here, several...This cell was able to operate at 24% efficiency which is very high for a silicon cell [Ref. 6]. The inverted pyramids labeled in the figure are

Electromagnetic tornadoes in space. Ion conics along auroral field lines generated by lower hybrid waves and electromagnetic turbulence in the ion-cyclotron range of frequencies

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

Chang, T.; Crew, G.B.; Retterer, J.M.

1988-01-01

The exotic phenomenon of energetic ion-conic formation by plasma waves in the magnetosphere is considered. Two particular transverse heating mechanisms are reviewed in detail: lower-hybrid energization of ions in the boundary layer of the plasma sheet, and electromagnetic ion cyclotron resonance heating in the central region of the plasma sheet. Mean particle calculations, plasma simulations, and analytical treatments of the heating processes are described.

Molecular and Isotopic Analysis of Earthworm Fecal Matter as a Tool for Determining Carbon Cycling Dynamics in two Great Lakes Region Forests

NASA Astrophysics Data System (ADS)

Top, S. M.; Filley, T. R.; Zurn-Birkhimer, S.

2009-12-01

Earthworms are frequently referred to as soil ecosystem engineers, reflecting their role as a potential major factor in controlling the dynamics of litter and soil organic matter transformations. Their significance is magnified when considering they are exotic in northern North American forests, humans acting as the main vector with transport of soil and recreational fishing. As a result of earthworm activity, forests can undergo significant changes to forest floor chemistry and soil structure, possibly increasing nutrient loss from both soil and leaf litter. The impact of earthworms on overall soil carbon stabilization/destabilization is largely unknown but likely a function of both species composition and edaphic soil properties. We are investigating the impacts of exotic earthworms on soils within two Great Lakes region forests; the Aspen free air CO2 enrichment (FACE) site, Rhinelander, WI, and forests in Red Lake Indian Reservation, MN. Aspen FACE provides an opportunity to document the changes that occur to forest chemistry and earthworm activity are a result of increased CO2, while the sites on the Red Lake Reservation are significant because of they contain a gradient of earthworm influence. At both sites earthworm populations were amassed from small pits and isolated to collect gut contents for isotopic and plant biopolymer chemistry analysis. Analysis are ongoing and will eventually include alkaline CuO extraction and isotopic analyses on the fecal matter, leaf litter, and soil to determine how plant biopolymers are vertically transported and mixed with soil from deeper horizons.

Decay analysis of compound nuclei formed in reactions with exotic neutron-rich 9Li projectile and the synthesis of 217At* within the dynamical cluster-decay model

NASA Astrophysics Data System (ADS)

Kaur, Arshdeep; Kaushal, Pooja; Hemdeep; Gupta, Raj K.

2018-01-01

The decay of various compound nuclei formed via exotic neutron-rich 9Li projectile is studied within the dynamical cluster-decay model (DCM). Following the earlier work of one of us (RKG) and collaborators (M. Kaur et al. (2015) [1]), for an empirically fixed neck-length parameter ΔRemp, the only parameter in the DCM, at a given incident laboratory energy ELab, we are able to fit almost exactly the (total) fusion cross section σfus =∑x=16σxn for 9Li projectile on 208Pb and other targets, with σfus depending strongly on the target mass of the most abundant isotope and its (magic) shell structure. This result shows the predictable nature of the DCM. The neck-length parameter ΔRemp is fixed empirically for the decay of 217At* formed in 9Li + 208Pb reaction at a fixed laboratory energy ELab, and then the total fusion cross section σfus calculated for all other reactions using 9Li as a projectile on different targets. Apparently, this procedure could be used to predict σfus for 9Li-induced reactions where experimental data are not available. Furthermore, optimum choice of "cold" target-projectile combinations, forming "hot" compact configurations, are predicted for the synthesis of compound nucleus 217At* with 8Li + 209Pb as one of the target-projectile combination, or another (t , p) combination 48Ca + 169Tb, with a doubly magic 48Ca, as the best possibility.

Design and Fabrication of Calibration Device for Scintillating Fibers of Tagger Microscope: For use in GlueX's QCD Experiment

NASA Astrophysics Data System (ADS)

Briere, Emily

2012-10-01

For decades, scientists have struggled to understand the chromo-electromagnetic field which confines quarks and gluons within the hadron. GlueX is a QCD experiment centered at Jefferson Lab, Virginia, seeking to better understand this gluonic field by exciting it and mapping the spectrum of exotic hybrid mesons that it generates. The experiment uses coherent bremsstrahlung radiation to produce a beam of photons, which due to their polarity act as virtual vector mesons. When incident on a liquid hydrogen target, these mesons are expected to form exotic hybrid mesons. Such particles quickly decay into new particles which are captured in a solenoid detector. The decays can then be reconstructed to examine the properties of the original exotic hybrid meson, although the initial energy of the photon is required to draw meaningful conclusions. The post-bremsstrahlung degraded electrons are bent from the main beam into the tagger microscope where they strike an array of scintillating optical fibers. Given the correlation between momentum and radial bend, the Silicon Photmultiplier sensors attached to the optical fibers are able to ``tag'' the electrons', and thus the photons', initial energies based on which fibers were hit. Providing central data for GlueX, the tagger microscope must be accurate. This paper details the design and fabrication of a scintillating fiber calibration device that moves horizontally above fiber bundles, using a green laser diode to direct light pulses into the fibers. This calibration method has been tested mechanically and via a Monte Carlo Matlab simulation, and has proven to be effective.

Thermodynamics of "exotic" Bañados-Teitelboim-Zanelli black holes.

PubMed

Townsend, Paul K; Zhang, Baocheng

2013-06-14

A number of three-dimensional (3D) gravity models, such as 3D conformal gravity, admit "exotic" black hole solutions: the metric is the same as the Bañados-Teitelboim-Zanelli metric of 3D Einstein gravity but with reversed roles for mass and angular momentum, and an entropy proportional to the length of the inner horizon instead of the event horizon. Here we show that the Bañados-Teitelboim-Zanelli solutions of the exotic 3D Einstein gravity (with parity-odd action but Einstein field equations) are exotic black holes, and we investigate their thermodynamics. The first and second laws of black hole thermodynamics still apply, and the entropy still has a statistical interpretation.

Issues and opportunities in exotic hadrons

DOE PAGES

Briceno, Raul A.; Cohen, Thomas D.; Coito, S.; ...

2016-04-01

The last few years have been witness to a proliferation of new results concerning heavy exotic hadrons. Experimentally, many new signals have been discovered that could be pointing towards the existence of tetraquarks, pentaquarks, and other exotic configurations of quarks and gluons. Theoretically, advances in lattice field theory techniques place us at the cusp of understanding complex coupled-channel phenomena, modelling grows more sophisticated, and effective field theories are being applied to an ever greater range of situations. Consequently, it is thus an opportune time to evaluate the status of the field. In the following, a series of high priority experimentalmore » and theoretical issues concerning heavy exotic hadrons is presented.« less

Are bison exotic in the Wrangell-St. Elias National Park and Preserve?

NASA Astrophysics Data System (ADS)

Peek, James M.; Miquelle, Dale G.; Wright, R. Gerald

1987-03-01

The effect of past distributions of animal populations now extinct in an area from unknown causes is considered relative to their status as exotic or native in national parks. The example is the bison (Bison bison) on the Copper and Chitina river drainages in Alaska in the USA which was introduced prior to establishment of Wrangell-St. Elias National Park and Preserve. The fossil record suggests that bison were present as recently as 500 years ago in Alaska. The policy of the US National Park Service to maintain natural ecosystems and restrict or eliminate exotic species raises the issue of whether this species should be treated as exotic or native.

Compounding and Extralabel Use of Drugs in Exotic Animal Medicine.

PubMed

Powers, Lauren V; Davidson, Gigi

2018-05-01

Extralabel drug use is the use of a Food and Drug Administration (FDA)-approved drug in a manner different from what is stipulated on the approved label. Compounding is the process of preparing a medication in a manner not indicated on the label to create a formulation specifically tailored to the needs of an individual patient. Extralabel drug use and compounding are vital aspects of safe and effective drug delivery to patients in exotic animal practice. There are few FDA-approved drugs for exotic animal species, and many approved drugs for other species are not available in suitable formulations for use in exotic animals. Copyright © 2018 Elsevier Inc. All rights reserved.

Synthesis of Exotic Soaps in the Chemistry Laboratory

NASA Astrophysics Data System (ADS)

Phanstiel, Otto, IV; Dueno, Eric; Xianghong Wang, Queenie

1998-05-01

A variety of different triglyceride sources ranging from Vietnamese garlic oil to a local restaurant's grill sludge were saponified to generate a series of exotic soaps. Students did not quantify their results, but described their products in terms of color, texture and odor. Their results were compared with existing data on the triglyceride content for each source used (when possible). Soap texture seemed to be related to the degree of unsaturation present in the starting triglyceride. However, texture alterations due to occluded impurities could not be ruled out. In general, fats and oils high in saturated fats (butter) gave hard, chunky, and waxlike soaps, while those high in unsaturated fats gave flaky and easily crumbled soaps (olive, corn, peanut and sunflower oils). Soap color was not consistent with triglyceride unsaturation levels during the time frame studied. Odor changes were dramatic and were explained in terms of a change in chemical structure (i.e. conversion from an ester to a carboxylate salt). In general, the experiment was well received by students and stressed the importance of making precise qualitative observations during the experiment.

Dimensional crossover and cold-atom realization of topological Mott insulators

PubMed Central

Scheurer, Mathias S.; Rachel, Stephan; Orth, Peter P.

2015-01-01

Interacting cold-atomic gases in optical lattices offer an experimental approach to outstanding problems of many body physics. One important example is the interplay of interaction and topology which promises to generate a variety of exotic phases such as the fractionalized Chern insulator or the topological Mott insulator. Both theoretically understanding these states of matter and finding suitable systems that host them have proven to be challenging problems. Here we propose a cold-atom setup where Hubbard on-site interactions give rise to spin liquid-like phases: weak and strong topological Mott insulators. They represent the celebrated paradigm of an interacting and topological quantum state with fractionalized spinon excitations that inherit the topology of the non-interacting system. Our proposal shall help to pave the way for a controlled experimental investigation of this exotic state of matter in optical lattices. Furthermore, it allows for the investigation of a dimensional crossover from a two-dimensional quantum spin Hall insulating phase to a three-dimensional strong topological insulator by tuning the hopping between the layers. PMID:25669431

Perfectly invisible PT -symmetric zero-gap systems, conformal field theoretical kinks, and exotic nonlinear supersymmetry

NASA Astrophysics Data System (ADS)

Guilarte, Juan Mateos; Plyushchay, Mikhail S.

2017-12-01

We investigate a special class of the PT -symmetric quantum models being perfectly invisible zero-gap systems with a unique bound state at the very edge of continuous spectrum of scattering states. The family includes the PT -regularized two particle Calogero systems (conformal quantum mechanics models of de Alfaro-Fubini-Furlan) and their rational extensions whose potentials satisfy equations of the KdV hierarchy and exhibit, particularly, a behaviour typical for extreme waves. We show that the two simplest Hamiltonians from the Calogero subfamily determine the fluctuation spectra around the PT -regularized kinks arising as traveling waves in the field-theoretical Liouville and SU(3) conformal Toda systems. Peculiar properties of the quantum systems are reflected in the associated exotic nonlinear supersymmetry in the unbroken or partially broken phases. The conventional N=2 supersymmetry is extended here to the N=4 nonlinear supersymmetry that involves two bosonic generators composed from Lax-Novikov integrals of the subsystems, one of which is the central charge of the superalgebra. Jordan states are shown to play an essential role in the construction.

Electronic and optical properties of novel carbon allotropes

DOE PAGES

Wang, Zhanyu; Dong, F.; Shen, B.; ...

2016-01-22

The vibrational properties, electronic structures and optical properties of novel carbon allotropes, such as monolayer penta-graphene (PG), double-layer PG and T12-carbon, were studied by first-principles calculations. Results of phonon calculations demonstrate that these exotic carbon allotropes are dynamically stable. The bulk T12 phase is an indirect-gap semiconductor having a quasiparticle (QP) bandgap of ~5.19 eV. When the bulk material transforms to a two-dimensional (2D) phase, the monolayer and double-layer PG become quasi-direct gap semiconductors with smaller QP bandgaps of ~4.48 eV and ~3.67 eV, respectively. Furthermore, the partial charge density analysis indicates that the 2D phases retain part of themore » electronic characteristics of the T12 phase. The linear photon energy-dependent dielectric functions and related optical properties including refractive index, extinction coefficient, absorption spectrum, reflectivity, and energy-loss spectrum were also computed and discussed. Additionally, the chemical stability of monolayer PG and the electronic and optical properties of double-side hydrogenated monolayer PG were also investigated. Furthermore, the results obtained from our calculations are beneficial to practical applications of these exotic carbon allotropes in optoelectronics and electronics.« less

Lake Ontario: Food web dynamics in a changing ecosystem (1970-2000)

USGS Publications Warehouse

Mills, E.L.; Casselman, J.M.; Dermott, R.; Fitzsimons, J.D.; Gal, G.; Holeck, K. T.; Hoyle, J.A.; Johannsson, O.E.; Lantry, B.F.; Makarewicz, J.C.; Millard, E.S.; Munawar, I.F.; Munawar, M.; O'Gorman, R.; Owens, R.W.; Rudstam, L. G.; Schaner, T.; Stewart, T.J.

2003-01-01

We examined stressors that have led to profound ecological changes in the Lake Ontario ecosystem and its fish community since 1970. The most notable changes have been reductions in phosphorus loading, invasion by Dreissena spp., fisheries management through stocking of exotic salmonids and control of sea lamprey (Petromyzon marinus), and fish harvest by anglers and double-crested cormorants (Phalacrocorax auritus). The response to these stressors has led to (i) declines in both algal photosynthesis and epilimnetic zooplankton production, (ii) decreases in alewife (Alosa pseudoharengus) abundance, (iii) declines in native Diporeia and lake whitefish (Coregonus clupeaformis), (iv) behavioral shifts in alewife spatial distribution benefitting native lake trout (Salvelinus namaycush), threespine stickleback (Gasterosteus aculeatus), and emerald shiner (Notropis atherinoides) populations, (v) dramatic increases in water clarity, (vi) predation impacts by cormorants on select fish species, and (vii) lake trout recruitment bottlenecks associated with alewife-induced thiamine deficiency. We expect stressor responses associated with anthropogenic forces like exotic species invasions and global climate warming to continue to impact the Lake Ontario ecosystem in the future and recommend continuous long-term ecological studies to enhance scientific understanding and management of this important resource.

Apparent competition and native consumers exacerbate the strong competitive effect of an exotic plant species.

PubMed

Orrock, John L; Dutra, Humberto P; Marquis, Robert J; Barber, Nicholas

2015-04-01

Direct and indirect effects can play a key role in invasions, but experiments evaluating both are rare. We examined the roles of direct competition and apparent competition by exotic Amur honeysuckle (Lonicera maackii) by manipulating (1) L. maackii vegetation, (2) presence of L. maackii fruits, and (3) access to plants by small mammals and deer. Direct competition with L. maackii reduced the abundance and richness of native and exotic species, and native consumers significantly reduced the abundance and richness of native species. Although effects of direct competition and consumption were more pervasive, richness of native plants was also reduced through apparent competition, as small-mammal consumers reduced richness only when L. maackii fruits were present. Our experiment reveals the multiple, interactive pathways that affect the success and impact of an invasive exotic plant: exotic plants may directly benefit from reduced attack by native consumers, may directly exert strong competitive effects on native plants, and may also benefit from apparent competition.

Impacts of mixed severity wildfire on exotic plants in a Colorado ponderosa pine-Douglas-fir forest

Treesearch

Paula J. Fornwalt; Merrill R. Kaufmann; Thomas J. Stohlgren

2010-01-01

The 2002 Hayman Fire burned with mixed severity across 55,800 ha of montane Colorado forest, including pre-existing plots that were originally measured for understory plant composition and cover in 1997. We examined the influence of the Hayman Fire on exotic plants by remeasuring these plots annually from 2003 to 2007. We found that (1) exotic richness and cover...

Meteors, space aliens, and other exotic encounters

Treesearch

Tom Hofacker

1998-01-01

Exotics have had a big impact on our environment. If you do not think so, just look at how many people believe that humans would not exist on this planet were it not for exotics. This belief centers on two main theories: (1) that humans could not have evolved were it not for a huge meteor from outer space striking the earth resulting in extinction of the dinasours, the...

Tamarisk control on public lands in the desert of southern California: two case studies

USGS Publications Warehouse

1994-01-01

As a land manager, the Federal Government faces enormous challenges from exotic pest invasions and associated changes to the structure and stability of native ecosystems (Bureau of Land Management, 1988). On public lands administered by the Bureau of Land Management (BLM) alone, it is estimated that almost three million hectares are occupied by invasive exotic plant species (weeds). Assuming an annual rate of invasion of 14 percent, 930 hectares of BLM-administered land are infested everyday by weeds (Jerry Asher, personal communication). When one considers the fact that BLM administers only about one-third of the public land in the United States (The Keystone Center, 1991), the magnitude of the problem assumes staggering proportions. The scenario described in the quote above portrays only some of the problems associated with the spread of the exotic plant tamarisk, a species on the California Exotic Pest Plant Council’s list of exotic pest plants of greatest concern (California Exotic Pest Plant Council, 1993). In this paper we review the threats posed by tamarisk invasion and proliferation and examine the traits that make the plant such a successful competitor. In addition, we highlight two tamarisk control efforts conducted by the Bureau of Land Management in the southern California desert.

Human migration is important in the international spread of exotic Salmonella serovars in animal and human populations.

PubMed

Iveson, J B; Bradshaw, S D; How, R A; Smith, D W

2014-11-01

The exposure of indigenous humans and native fauna in Australia and the Wallacea zoogeographical region of Indonesia to exotic Salmonella serovars commenced during the colonial period and has accelerated with urbanization and international travel. In this study, the distribution and prevalence of exotic Salmonella serovars are mapped to assess the extent to which introduced infections are invading native wildlife in areas of high natural biodiversity under threat from expanding human activity. The major exotic Salmonella serovars, Bovismorbificans, Derby, Javiana, Newport, Panama, Saintpaul and Typhimurium, isolated from wildlife on populated coastal islands in southern temperate areas of Western Australia, were mostly absent from reptiles and native mammals in less populated tropical areas of the state. They were also not recorded on the uninhabited Mitchell Plateau or islands of the Bonaparte Archipelago, adjacent to south-eastern Indonesia. Exotic serovars were, however, isolated in wildlife on 14/17 islands sampled in the Wallacea region of Indonesia and several islands off the west coast of Perth. Increases in international tourism, involving islands such as Bali, have resulted in the isolation of a high proportion of exotic serovar infections suggesting that densely populated island resorts in the Asian region are acting as staging posts for the interchange of Salmonella infections between tropical and temperate regions.

Biodiversity, photosynthetic mode, and ecosystem services differ between native and novel ecosystems.

PubMed

Martin, Leanne M; Polley, H Wayne; Daneshgar, Pedram P; Harris, Mary A; Wilsey, Brian J

2014-06-01

Human activities have caused non-native plant species with novel ecological interactions to persist on landscapes, and it remains controversial whether these species alter multiple aspects of communities and ecosystems. We tested whether native and exotic grasslands differ in species diversity, ecosystem services, and an important aspect of functional diversity (C3:C4 proportions) by sampling 42 sites along a latitudinal gradient and conducting a controlled experiment. Exotic-dominated grasslands had drastically lower plant diversity and slightly higher tissue N concentrations and forage quality compared to native-dominated sites. Exotic sites were strongly dominated by C4 species at southern and C3 species at northern latitudes with a sharp transition at 36-38°, whereas native sites contained C3:C4 mixtures. Large differences in C3:C4 proportions and temporal niche partitioning were found between native and exotic mixtures in the experiment, implying that differences in C3:C4 proportions along the latitudinal gradient are caused partially by species themselves. Our results indicate that the replacement of native- by exotic-dominated grasslands has created a management tradeoff (high diversity versus high levels of certain ecosystem services) and that models of global change impacts and C3/C4 distribution should consider effects of exotic species.

Tevatron constraints on models of the Higgs boson with exotic spin and parity using decays to bottom-antibottom quark pairs.

PubMed

Aaltonen, T; Abazov, V M; Abbott, B; Acharya, B S; Adams, M; Adams, T; Agnew, J P; Alexeev, G D; Alkhazov, G; Alton, A; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Askew, A; Atkins, S; Auerbach, B; Augsten, K; Aurisano, A; Avila, C; Azfar, F; Badaud, F; Badgett, W; Bae, T; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barbaro-Galtieri, A; Barberis, E; Baringer, P; Barnes, V E; Barnett, B A; Barria, P; Bartlett, J F; Bartos, P; Bassler, U; Bauce, M; Bazterra, V; Bean, A; Bedeschi, F; Begalli, M; Behari, S; Bellantoni, L; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bhat, P C; Bhatia, S; Bhatnagar, V; Bhatti, A; Bland, K R; Blazey, G; Blessing, S; Bloom, K; Blumenfeld, B; Bocci, A; Bodek, A; Boehnlein, A; Boline, D; Boos, E E; Borissov, G; Bortoletto, D; Borysova, M; Boudreau, J; Boveia, A; Brandt, A; Brandt, O; Brigliadori, L; Brock, R; Bromberg, C; Bross, A; Brown, D; Brucken, E; Bu, X B; Budagov, J; Budd, H S; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burkett, K; Busetto, G; Bussey, P; Buszello, C P; Butti, P; Buzatu, A; Calamba, A; Camacho-Pérez, E; Camarda, S; Campanelli, M; Canelli, F; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Casal, B; Casarsa, M; Casey, B C K; Castilla-Valdez, H; Castro, A; Catastini, P; Caughron, S; Cauz, D; Cavaliere, V; Cerri, A; Cerrito, L; Chakrabarti, S; Chan, K M; Chandra, A; Chapon, E; Chen, G; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Cho, K; Cho, S W; Choi, S; Chokheli, D; Choudhary, B; Cihangir, S; Claes, D; Clark, A; Clarke, C; Clutter, J; Convery, M E; Conway, J; Cooke, M; Cooper, W E; Corbo, M; Corcoran, M; Cordelli, M; Couderc, F; Cousinou, M-C; Cox, C A; Cox, D J; Cremonesi, M; Cruz, D; Cuevas, J; Culbertson, R; Cutts, D; Das, A; d'Ascenzo, N; Datta, M; Davies, G; de Barbaro, P; de Jong, S J; De La Cruz-Burelo, E; Déliot, F; Demina, R; Demortier, L; Deninno, M; Denisov, D; Denisov, S P; D'Errico, M; Desai, S; Deterre, C; DeVaughan, K; Devoto, F; Di Canto, A; Di Ruzza, B; Diehl, H T; Diesburg, M; Ding, P F; Dittmann, J R; Dominguez, A; Donati, S; D'Onofrio, M; Dorigo, M; Driutti, A; Dubey, A; Dudko, L V; Duperrin, A; Dutt, S; Eads, M; Ebina, K; Edgar, R; Edmunds, D; Elagin, A; Ellison, J; Elvira, V D; Enari, Y; Erbacher, R; Errede, S; Esham, B; Evans, H; Evdokimov, V N; Farrington, S; Fauré, A; Feng, L; Ferbel, T; Fernández Ramos, J P; Fiedler, F; Field, R; Filthaut, F; Fisher, W; Fisk, H E; Flanagan, G; Forrest, R; Fortner, M; Fox, H; Franklin, M; Freeman, J C; Frisch, H; Fuess, S; Funakoshi, Y; Galloni, C; Garbincius, P H; Garcia-Bellido, A; García-González, J A; Garfinkel, A F; Garosi, P; Gavrilov, V; Geng, W; Gerber, C E; Gerberich, H; Gerchtein, E; Gershtein, Y; Giagu, S; Giakoumopoulou, V; Gibson, K; Ginsburg, C M; Ginther, G; Giokaris, N; Giromini, P; Glagolev, V; Glenzinski, D; Gogota, O; Gold, M; Goldin, D; Golossanov, A; Golovanov, G; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González López, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gramellini, E; Grannis, P D; Greder, S; Greenlee, H; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grosso-Pilcher, C; Group, R C; Grünendahl, S; Grünewald, M W; Guillemin, T; Guimaraes da Costa, J; Gutierrez, G; Gutierrez, P; Hahn, S R; Haley, J; Han, J Y; Han, L; Happacher, F; Hara, K; Harder, K; Hare, M; Harel, A; Harr, R F; Harrington-Taber, T; Hatakeyama, K; Hauptman, J M; Hays, C; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinrich, J; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herndon, M; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hocker, A; Hoeneisen, B; Hogan, J; Hohlfeld, M; Holzbauer, J L; Hong, Z; Hopkins, W; Hou, S; Howley, I; Hubacek, Z; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Hynek, V; Iashvili, I; Ilchenko, Y; Illingworth, R; Introzzi, G; Iori, M; Ito, A S; Ivanov, A; Jabeen, S; Jaffré, M; James, E; Jang, D; Jayasinghe, A; Jayatilaka, B; Jeon, E J; Jeong, M S; Jesik, R; Jiang, P; Jindariani, S; Johns, K; Johnson, E; Johnson, M; Jonckheere, A; Jones, M; Jonsson, P; Joo, K K; Joshi, J; Jun, S Y; Jung, A W; Junk, T R; Juste, A; Kajfasz, E; Kambeitz, M; Kamon, T; Karchin, P E; Karmanov, D; Kasmi, A; Kato, Y; Katsanos, I; Kaur, M; Kehoe, R; Kermiche, S; Ketchum, W; Keung, J; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S H; Kim, S B; Kim, Y J; Kim, Y K; Kimura, N; Kirby, M; Kiselevich, I; Knoepfel, K; Kohli, J M; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kozelov, A V; Kraus, J; Kreps, M; Kroll, J; Kruse, M; Kuhr, T; Kumar, A; Kupco, A; Kurata, M; Kurča, T; Kuzmin, V A; Laasanen, A T; Lammel, S; Lammers, S; Lancaster, M; Lannon, K; Latino, G; Lebrun, P; Lee, H S; Lee, H S; Lee, J S; Lee, S W; Lee, W M; Lei, X; Lellouch, J; Leo, S; Leone, S; Lewis, J D; Li, D; Li, H; Li, L; Li, Q Z; Lim, J K; Limosani, A; Lincoln, D; Linnemann, J; Lipaev, V V; Lipeles, E; Lipton, R; Lister, A; Liu, H; Liu, H; Liu, Q; Liu, T; Liu, Y; Lobodenko, A; Lockwitz, S; Loginov, A; Lokajicek, M; Lopes de Sa, R; Lucchesi, D; Lucà, A; Lueck, J; Lujan, P; Lukens, P; Luna-Garcia, R; Lungu, G; Lyon, A L; Lys, J; Lysak, R; Maciel, A K A; Madar, R; Madrak, R; Maestro, P; Magaña-Villalba, R; Malik, S; Malik, S; Malyshev, V L; Manca, G; Manousakis-Katsikakis, A; Mansour, J; Marchese, L; Margaroli, F; Marino, P; Martínez-Ortega, J; Matera, K; Mattson, M E; Mazzacane, A; Mazzanti, P; McCarthy, R; McGivern, C L; McNulty, R; Mehta, A; Mehtala, P; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Mesropian, C; Meyer, A; Meyer, J; Miao, T; Miconi, F; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondal, N K; Moon, C S; Moore, R; Morello, M J; Mukherjee, A; Mulhearn, M; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nagy, E; Nakano, I; Napier, A; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Nett, J; Neu, C; Neustroev, P; Nguyen, H T; Nigmanov, T; Nodulman, L; Noh, S Y; Norniella, O; Nunnemann, T; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Orduna, J; Ortolan, L; Osman, N; Osta, J; Pagliarone, C; Pal, A; Palencia, E; Palni, P; Papadimitriou, V; Parashar, N; Parihar, V; Park, S K; Parker, W; Partridge, R; Parua, N; Patwa, A; Pauletta, G; Paulini, M; Paus, C; Penning, B; Perfilov, M; Peters, Y; Petridis, K; Petrillo, G; Pétroff, P; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pleier, M-A; Podstavkov, V M; Pondrom, L; Popov, A V; Poprocki, S; Potamianos, K; Pranko, A; Prewitt, M; Price, D; Prokopenko, N; Prokoshin, F; Ptohos, F; Punzi, G; Qian, J; Quadt, A; Quinn, B; Ratoff, P N; Razumov, I; Redondo Fernández, I; Renton, P; Rescigno, M; Rimondi, F; Ripp-Baudot, I; Ristori, L; Rizatdinova, F; Robson, A; Rodriguez, T; Rolli, S; Rominsky, M; Ronzani, M; Roser, R; Rosner, J L; Ross, A; Royon, C; Rubinov, P; Ruchti, R; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Sajot, G; Sakumoto, W K; Sakurai, Y; Sánchez-Hernández, A; Sanders, M P; Santi, L; Santos, A S; Sato, K; Savage, G; Saveliev, V; Savitskyi, M; Savoy-Navarro, A; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schlabach, P; Schmidt, E E; Schwanenberger, C; Schwarz, T; Schwienhorst, R; Scodellaro, L; Scuri, F; Seidel, S; Seiya, Y; Sekaric, J; Semenov, A; Severini, H; Sforza, F; Shabalina, E; Shalhout, S Z; Shary, V; Shaw, S; Shchukin, A A; Shears, T; Shepard, P F; Shimojima, M; Shochet, M; Shreyber-Tecker, I; Simak, V; Simonenko, A; Skubic, P; Slattery, P; Sliwa, K; Smirnov, D; Smith, J R; Snider, F D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Song, H; Sonnenschein, L; Sorin, V; Soustruznik, K; St Denis, R; Stancari, M; Stark, J; Stentz, D; Stoyanova, D A; Strauss, M; Strologas, J; Sudo, Y; Sukhanov, A; Suslov, I; Suter, L; Svoisky, P; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thomson, E; Thukral, V; Titov, M; Toback, D; Tokar, S; Tokmenin, V V; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Tsai, Y-T; Tsybychev, D; Tuchming, B; Tully, C; Ukegawa, F; Uozumi, S; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Vázquez, F; Velev, G; Vellidis, C; Verkheev, A Y; Vernieri, C; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vidal, M; Vilanova, D; Vilar, R; Vizán, J; Vogel, M; Vokac, P; Volpi, G; Wagner, P; Wahl, H D; Wallny, R; Wang, M H L S; Wang, S M; Warchol, J; Waters, D; Watts, G; Wayne, M; Weichert, J; Welty-Rieger, L; Wester, W C; Whiteson, D; Wicklund, A B; Wilbur, S; Williams, H H; Williams, M R J; Wilson, G W; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wobisch, M; Wolbers, S; Wolfe, H; Wood, D R; Wright, T; Wu, X; Wu, Z; Wyatt, T R; Xie, Y; Yamada, R; Yamamoto, K; Yamato, D; Yang, S; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yasuda, T; Yatsunenko, Y A; Ye, W; Ye, Z; Yeh, G P; Yi, K; Yin, H; Yip, K; Yoh, J; Yorita, K; Yoshida, T; Youn, S W; Yu, G B; Yu, I; Yu, J M; Zanetti, A M; Zeng, Y; Zennamo, J; Zhao, T G; Zhou, B; Zhou, C; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L; Zucchelli, S

2015-04-17

Combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin J and parity P are presented and compared with results obtained assuming the standard model value JP=0+. Both collaborations analyzed approximately 10  fb(-) of proton-antiproton collisions with a center-of-mass energy of 1.96 TeV collected at the Fermilab Tevatron. Two models predicting exotic Higgs bosons with JP=0- and JP=2+ are tested. The kinematic properties of exotic Higgs boson production in association with a vector boson differ from those predicted for the standard model Higgs boson. Upper limits at the 95% credibility level on the production rates of the exotic Higgs bosons, expressed as fractions of the standard model Higgs boson production rate, are set at 0.36 for both the JP=0- hypothesis and the JP=2+ hypothesis. If the production rate times the branching ratio to a bottom-antibottom pair is the same as that predicted for the standard model Higgs boson, then the exotic bosons are excluded with significances of 5.0 standard deviations and 4.9 standard deviations for the JP=0- and JP=2+ hypotheses, respectively.

Effects of an exotic prey species on a native specialist: example of the snail kite

USGS Publications Warehouse

Cattau, Christopher E.; Martin, J.; Kitchens, Wiley M.

2010-01-01

Despite acknowledging that exotic species can exhibit tremendous influence over native populations, few case studies have clearly demonstrated the effects of exotic prey species on native predators. We examined the effects of the recently introduced island apple snail (Pomacea insularum) on the foraging behavior and energetics of the endangered snail kite (Rostrhamus sociabilis plumbeus) in Florida. We conducted time-activity budgets: (i) on kites foraging for native Florida apple snails (Pomacea paludosa) in major wetland units within the kites' range that had not been invaded by the exotic island apple snail and (ii) on kites foraging for exotic apple snails in Lake Tohopekaliga, the only major wetland utilized by the snail kite that had suffered a serious invasion of P. insularum. When foraging for P. insularum, snail kites dropped a greater proportion of snails, and they experienced increased handling times and decreased consumption rates; however, kites foraging for P. insularum also spent a smaller proportion of the day in flight. Estimates of net daily energy balances between kites feeding on P. insularum versus P. paludosa were comparable for adults, but juveniles experienced energetic deficiencies when feeding on the exotic snail. Due to this discrepancy, we hypothesize that wetlands invaded by P. insularum, such as Lake Tohopekaliga, may function as ecological traps for the snail kite in Florida by attracting breeding adults but simultaneously depressing juvenile survival. This study highlights the conservation implications and importance of elucidating the effects that exotic species have on native specialists, especially those that are endangered, because subtle influences on behavior may have significant population consequences.

Effects of an exotic prey species on a native specialist: Eexample of the snail kite

USGS Publications Warehouse

Cattau, Christopher E.; Martin, J.; Kitchens, W.M.

2010-01-01

Despite acknowledging that exotic species can exhibit tremendous influence over native populations, few case studies have clearly demonstrated the effects of exotic prey species on native predators. We examined the effects of the recently introduced island apple snail (Pomacea insularum) on the foraging behavior and energetics of the endangered snail kite (Rostrhamus sociabilis plumbeus) in Florida. We conducted time-activity budgets: (i) on kites foraging for native Florida apple snails (Pomacea paludosa) in major wetland units within the kites' range that had not been invaded by the exotic island apple snail and (ii) on kites foraging for exotic apple snails in Lake Tohopekaliga, the only major wetland utilized by the snail kite that had suffered a serious invasion of P. insularum. When foraging for P. insularum, snail kites dropped a greater proportion of snails, and they experienced increased handling times and decreased consumption rates; however, kites foraging for P. insularum also spent a smaller proportion of the day in flight. Estimates of net daily energy balances between kites feeding on P. insularum versus P. paludosa were comparable for adults, but juveniles experienced energetic deficiencies when feeding on the exotic snail. Due to this discrepancy, we hypothesize that wetlands invaded by P. insularum, such as Lake Tohopekaliga, may function as ecological traps for the snail kite in Florida by attracting breeding adults but simultaneously depressing juvenile survival. This study highlights the conservation implications and importance of elucidating the effects that exotic species have on native specialists, especially those that are endangered, because subtle influences on behavior may have significant population consequences. ?? 2009 Elsevier Ltd.

Demographic changes following mechanical removal of exotic brown trout in an Intermountain West (USA), high-elevation stream

USGS Publications Warehouse

Saunders, W. Carl; Budy, Phaedra E.; Thiede, Gary P.

2015-01-01

Exotic species present a great threat to native fish conservation; however, eradicating exotics is expensive and often impractical. Mechanical removal can be ineffective for eradication, but nonetheless may increase management effectiveness by identifying portions of a watershed that are strong sources of exotics. We used mechanical removal to understand processes driving exotic brown trout (Salmo trutta) populations in the Logan River, Utah. Our goals were to: (i) evaluate the demographic response of brown trout to mechanical removal, (ii) identify sources of brown trout recruitment at a watershed scale and (iii) evaluate whether mechanical removal can reduce brown trout densities. We removed brown trout from 2 km of the Logan River (4174 fish), and 5.6 km of Right Hand Fork (RHF, 15,245 fish), a low-elevation tributary, using single-pass electrofishing. We compared fish abundance and size distributions prior to, and after 2 years of mechanical removal. In the Logan River, immigration to the removal reach and high natural variability in fish abundances limited the response to mechanical removal. In contrast, mechanical removal in RHF resulted in a strong recruitment pulse, shifting the size distribution towards smaller fish. These results suggest that, before removal, density-dependent mortality or emigration of juvenile fish stabilised adult populations and may have provided a source of juveniles to the main stem. Overall, in sites demonstrating strong density-dependent population regulation, or near sources of exotics, short-term mechanical removal has limited effects on brown trout populations but may help identify factors governing populations and inform large-scale management of exotic species.

Accounting for sampling patterns reverses the relative importance of trade and climate for the global sharing of exotic plants

USGS Publications Warehouse

Sofaer, Helen R.; Jarnevich, Catherine S.

2017-01-01

AimThe distributions of exotic species reflect patterns of human-mediated dispersal, species climatic tolerances and a suite of other biotic and abiotic factors. The relative importance of each of these factors will shape how the spread of exotic species is affected by ongoing economic globalization and climate change. However, patterns of trade may be correlated with variation in scientific sampling effort globally, potentially confounding studies that do not account for sampling patterns.LocationGlobal.Time periodMuseum records, generally from the 1800s up to 2015.Major taxa studiedPlant species exotic to the United States.MethodsWe used data from the Global Biodiversity Information Facility (GBIF) to summarize the number of plant species with exotic occurrences in the United States that also occur in each other country world-wide. We assessed the relative importance of trade and climatic similarity for explaining variation in the number of shared species while evaluating several methods to account for variation in sampling effort among countries.ResultsAccounting for variation in sampling effort reversed the relative importance of trade and climate for explaining numbers of shared species. Trade was strongly correlated with numbers of shared U.S. exotic plants between the United States and other countries before, but not after, accounting for sampling variation among countries. Conversely, accounting for sampling effort strengthened the relationship between climatic similarity and species sharing. Using the number of records as a measure of sampling effort provided a straightforward approach for the analysis of occurrence data, whereas species richness estimators and rarefaction were less effective at removing sampling bias.Main conclusionsOur work provides support for broad-scale climatic limitation on the distributions of exotic species, illustrates the need to account for variation in sampling effort in large biodiversity databases, and highlights the difficulty in inferring causal links between the economic drivers of invasion and global patterns of exotic species occurrence.

Diversity patterns and composition of native and exotic floras in central Chile

NASA Astrophysics Data System (ADS)

Figueroa, Javier A.; Teillier, Sebastián; Castro, Sergio A.

2011-03-01

Floristic changes in the Mediterranean region of central Chile brought about by human impact appear to be shared with other climatic regions, although there is a notable absence of empirical studies and available quantitative evidence for the central Chile region. This study examines the cover, richness and composition of native and exotic plant species in a representative area of central Chile. Through floristic characterization of 33 sites sampled using 40 × 40 m plots distributed along transect on which the two farthest sites were separated by 50 km, the floristic richness and cover patterns, as well as the general land use characteristics were evaluated (native matorral, espinal, abandoned farming field, forest plantations, periurban sites, road sites, river bank, and burnt site). We recorded 327 species of plants; 213 species were native and 114 were exotic. The average number of species was heterogeneous in all sites, showing a greater relative native frequency in those sites with a lower level of anthropic intervention. Except for the matorral, the cover of exotic species was greater than that of native species. No relation was found between richness and cover in relation to the different types of land use. The relationship between cover of native and exotic was negative, although for richness did not show relationship. Results show that the exotic species are limited by resources, although they have not completely displaced the native species. The native and exotic floras respond to different spatial distribution patterns, so their presence makes it possible to establish two facts rarely quantified in central Chile: first, that the exotic flora replaces (but does not necessarily displace) the native flora, and second, that at the same time, because of its greater geographic ubiquity and the abundance levels that it achieves, it contributes to the taxonomic and physiognomic homogenization of central Chile.

Interactive effects of deer exclusion and exotic plant removal on deciduous forest understory communities

USGS Publications Warehouse

Bourg, Norman; McShea, William J.; Herrmann, Valentine; Stewart, Chad M.

2017-01-01

Mammalian herbivory and exotic plant species interactions are an important ongoing research topic, due to their presumed impacts on native biodiversity. The extent to which these interactions affect forest understory plant community composition and persistence was the subject of our study. We conducted a 5-year, 2 × 2 factorial experiment in three mid-Atlantic US deciduous forests with high densities of white-tailed deer (Odocoileus virginianus) and exotic understory plants. We predicted: (i) only deer exclusion and exotic plant removal in tandem would increase native plant species metrics; and (ii) deer exclusion alone would decrease exotic plant abundance over time. Treatments combining exotic invasive plant removal and deer exclusion for plots with high initial cover, while not differing from fenced or exotic removal only plots, were the only ones to exhibit positive richness responses by native herbaceous plants compared to control plots. Woody seedling metrics were not affected by any treatments. Deer exclusion caused significant increases in abundance and richness of native woody species >30 cm in height. Abundance changes in two focal members of the native sapling community showed that oaks (Quercus spp.) increased only with combined exotic removal and deer exclusion, while shade-tolerant maples (Acer spp.) showed no changes. We also found significant declines in invasive Japanese stiltgrass (Microstegium vimineum) abundance in deer-excluded plots. Our study demonstrates alien invasive plants and deer impact different components and life-history stages of the forest plant community, and controlling both is needed to enhance understory richness and abundance. Alien plant removal combined with deer exclusion will most benefit native herbaceous species richness under high invasive cover conditions while neither action may impact native woody seedlings. For larger native woody species, only deer exclusion is needed for such increases. Deer exclusion directly facilitated declines in invasive species abundance. Resource managers should consider addressing both factors to achieve their forest management goals.

Contrasting Effects of Land Use Intensity and Exotic Host Plants on the Specialization of Interactions in Plant-Herbivore Networks

PubMed Central

de Araújo, Walter Santos; Vieira, Marcos Costa; Lewinsohn, Thomas M.; Almeida-Neto, Mário

2015-01-01

Human land use tends to decrease the diversity of native plant species and facilitate the invasion and establishment of exotic ones. Such changes in land use and plant community composition usually have negative impacts on the assemblages of native herbivorous insects. Highly specialized herbivores are expected to be especially sensitive to land use intensification and the presence of exotic plant species because they are neither capable of consuming alternative plant species of the native flora nor exotic plant species. Therefore, higher levels of land use intensity might reduce the proportion of highly specialized herbivores, which ultimately would lead to changes in the specialization of interactions in plant-herbivore networks. This study investigates the community-wide effects of land use intensity on the degree of specialization of 72 plant-herbivore networks, including effects mediated by the increase in the proportion of exotic plant species. Contrary to our expectation, the net effect of land use intensity on network specialization was positive. However, this positive effect of land use intensity was partially canceled by an opposite effect of the proportion of exotic plant species on network specialization. When we analyzed networks composed exclusively of endophagous herbivores separately from those composed exclusively of exophagous herbivores, we found that only endophages showed a consistent change in network specialization at higher land use levels. Altogether, these results indicate that land use intensity is an important ecological driver of network specialization, by way of reducing the local host range of herbivore guilds with highly specialized feeding habits. However, because the effect of land use intensity is offset by an opposite effect owing to the proportion of exotic host species, the net effect of land use in a given herbivore assemblage will likely depend on the extent of the replacement of native host species with exotic ones. PMID:25565141

Contrasting effects of land use intensity and exotic host plants on the specialization of interactions in plant-herbivore networks.

PubMed

de Araújo, Walter Santos; Vieira, Marcos Costa; Lewinsohn, Thomas M; Almeida-Neto, Mário

2015-01-01

Human land use tends to decrease the diversity of native plant species and facilitate the invasion and establishment of exotic ones. Such changes in land use and plant community composition usually have negative impacts on the assemblages of native herbivorous insects. Highly specialized herbivores are expected to be especially sensitive to land use intensification and the presence of exotic plant species because they are neither capable of consuming alternative plant species of the native flora nor exotic plant species. Therefore, higher levels of land use intensity might reduce the proportion of highly specialized herbivores, which ultimately would lead to changes in the specialization of interactions in plant-herbivore networks. This study investigates the community-wide effects of land use intensity on the degree of specialization of 72 plant-herbivore networks, including effects mediated by the increase in the proportion of exotic plant species. Contrary to our expectation, the net effect of land use intensity on network specialization was positive. However, this positive effect of land use intensity was partially canceled by an opposite effect of the proportion of exotic plant species on network specialization. When we analyzed networks composed exclusively of endophagous herbivores separately from those composed exclusively of exophagous herbivores, we found that only endophages showed a consistent change in network specialization at higher land use levels. Altogether, these results indicate that land use intensity is an important ecological driver of network specialization, by way of reducing the local host range of herbivore guilds with highly specialized feeding habits. However, because the effect of land use intensity is offset by an opposite effect owing to the proportion of exotic host species, the net effect of land use in a given herbivore assemblage will likely depend on the extent of the replacement of native host species with exotic ones.

Bias field tunable magnetic configuration and magnetization dynamics in Ni80Fe20 nano-cross structures with varying arm length

NASA Astrophysics Data System (ADS)

Adhikari, K.; Choudhury, S.; Mandal, R.; Barman, S.; Otani, Y.; Barman, A.

2017-01-01

Ferromagnetic nano-cross structures promise exotic static magnetic configurations and very rich and tunable magnetization dynamics leading towards potential applications in magnetic logic and communication devices. Here, we report an experimental study of external magnetic field tunable static magnetic configurations and magnetization dynamics in Ni80Fe20 nano-cross structures with varying arm lengths (L). Broadband ferromagnetic resonance measurements showed a strong variation in the number of spin-wave (SW) modes and mode frequencies (f) with bias field magnitude (H). Simulated static magnetic configurations and SW mode profiles explain the rich variation of the SW spectra, including mode softening, mode crossover, mode splitting, and mode merging. Such variation of SW spectra is further modified by the size of the nano-cross. Remarkably, with decreasing arm length of nano-cross structures, the onion magnetization ground state becomes more stable. Calculated magnetostatic field distributions support the above observations and revealed the non-collective nature of the dynamics in closely packed nano-cross structures. The latter is useful for their possible applications in magnetic storage and memory devices.

Impact of environment on dynamics of exciton complexes in a WS2 monolayer

NASA Astrophysics Data System (ADS)

Jakubczyk, Tomasz; Nogajewski, Karol; Molas, Maciej R.; Bartos, Miroslav; Langbein, Wolfgang; Potemski, Marek; Kasprzak, Jacek

2018-07-01

Scientific curiosity to uncover original optical properties and functionalities of atomically thin semiconductors, stemming from unusual Coulomb interactions in the two-dimensional geometry and multi-valley band structure, drives the research on monolayers of transition metal dichalcogenides (TMDs). While recent works ascertained the exotic energetic schemes of exciton complexes in TMDs, we here infer their unusual coherent dynamics occurring on subpicosecond time scale. The dynamics is largely affected by the disorder landscape on the submicron scale, thus can be uncovered using four-wave mixing in the frequency domain, which enables microscopic investigations and imaging. Focusing on a WS2 monolayer, we observe that exciton coherence is lost primarily due to interaction with phonons and relaxation processes towards optically dark excitonic states. Notably, when temperature is low and disorder weak, excitons large coherence volume results in enhanced oscillator strength, allowing to reach the regime of radiatively limited dephasing. Additionally, we observe long valley coherence for the negatively charged exciton complex. We therefore elucidate the crucial role of exciton environment in the TMDs on its dynamics and show that revealed mechanisms are ubiquitous within this family.

The United States Experience with the Exotic Cerambycid Anoplophora glabripennis: Detection, Quarantine, and Control

Treesearch

Robert A. Haack; Therese M. Poland; Rui-Tong Gao

2000-01-01

It is estimated that there are at least 4500 exotic (non-indigenous) organisms currently established in the United States(US) (US Congress 1993) and possibly as many as 50,000 (Pimentel et al. 2000). Of the many exotic organisms now in the US, more than 400 are insects that feed on trees and shrubs.(Haack and Byler 1993, Mattson et al. 1994, Niemela and Mattson 1996)....

Exotic nuclear systems with strangeness: Hypernuclei and Kaonic nuclei

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

Dote, Akinobu

2010-05-12

Nuclear systems with strangeness, hypernuclei and kaonic nuclei, are expected to have lots of interesting properties. In this article, after the recent development of hypernuclear study is reviewed, we report two results of our study of hypernuclei with antisymmetrized molecular dynamics; 1) impurity effect of LAMBDA on {sub L}AMBDA{sup 20}Ne, and 2){sub X}I{sup 12}Be studied with three kinds of XIN potentials. The current status of studies of kaonic nuclei is also introduced and our study with a phenomenological and a chiral-based K-barN potential are reported.

The Modification of an Estuary

NASA Astrophysics Data System (ADS)

Nichols, Frederic H.; Cloern, James E.; Luoma, Samuel N.; Peterson, David H.

1986-02-01

The San Francisco Bay estuary has been rapidly modified by human activity. Diking and filling of most of its wetlands have eliminated habitats for fish and waterfowl; the introduction of exotic species has transformed the composition of its aquatic communities; reduction of freshwater inflow by more than half has changed the dynamics of its plant and animal communities; and wastes have contaminated its sediments and organisms. Continued disposal of toxic wastes, the probable further reduction in freshwater inflow, and the possible synergy between the two provide the potential for further alteration of the estuary's water quality and biotic communities.

The modification of an estuary

USGS Publications Warehouse

Nichols, F.H.; Cloern, J.E.; Luoma, S.N.; Peterson, D.H.

1986-01-01

The San Francisco Bay estuary has been rapidly modified by human activity. Diking and filling of most of its wetlands have eliminated habitats for fish and waterfowl; the introduction of exotic species has transformed the composition of its aquatic communities; reduction of freshwater inflow by more than half has changed the dynamics of its plant and animal communities; and wastes have contaminated its sediments and organisms. Continued disposal of toxic wastes, the probable further reduction in freshwater inflow, and the possible synergy between the two provide the potential for further alteration of the estuary's water quality and biotic communities.

Nuclear physics with antiprotons

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

Dover, C.B.

1984-01-01

Transparencies of an invited talk presented at the Nashville meeting of the American Physical Society, October 18-20, 1984, are included. Topics include: (1) Salient features of two-body N anti N interactions (N anti N reversible NN, annihilation mechanisms (quark models), and optical model phenomenology); (2) anti N-nucleus interactions - elastic, inelastic, etc. (new cross section data, optical potentials, signatures of spin-isospin dependence of N anti N force, and (anti p, p) reactions); and (3) anti N-nucleus annihilation processes (features of cascade or fluid dynamics calculations, searches for baryonium and other exotics, meson interferometry, and (anti p, NN) reactions. (WHK)

A forecast of new test capabilities using Magnetic Suspension and Balance Systems

NASA Technical Reports Server (NTRS)

Lawing, Pierce L.; Johnson, William G., Jr.

1988-01-01

This paper outlines the potential of Magnetic Suspension and Balance System (MSBS) technology to solve existing problems related to support interference in wind tunnels. Improvement of existing test techniques and exciting new techniques are envisioned as a result of applying MSBS. These include improved data accuracy, dynamic stability testing, two-body/stores release testing, and pilot/designer-in-the-loop tests. It also discusses the use of MSBS for testing exotic configurations such as hybrid hypersonic vehicles. A new facility concept that combines features of ballistic tubes, magnetic suspension, and cryogenic tunnels is described.

General monogamy relation for the entanglement of formation in multiqubit systems.

PubMed

Bai, Yan-Kui; Xu, Yuan-Fei; Wang, Z D

2014-09-05

We prove exactly that the squared entanglement of formation, which quantifies the bipartite entanglement, obeys a general monogamy inequality in an arbitrary multiqubit mixed state. Based on this kind of exotic monogamy relation, we are able to construct two sets of useful entanglement indicators: the first one can detect all genuine multiqubit entangled states even in the case of the two-qubit concurrence and n-tangles being zero, while the second one can be calculated via quantum discord and applied to multipartite entanglement dynamics. Moreover, we give a computable and nontrivial lower bound for multiqubit entanglement of formation.

9 CFR 352.17 - Transportation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.17 Transportation. This shall...

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

Salmi, Petja; Sutcliffe, Paul

The aloof baby Skyrme model is a (2+1)-dimensional theory with solitons that are lightly bound. It is a low-dimensional analogue of a similar Skyrme model in (3+1)- dimensions, where the lightly bound solitons have binding energies comparable to nuclei. A previous study of static solitons in the aloof baby Skyrme model revealed that multi-soliton bound states have a cluster structure, with constituents that preserve their individual identities due to the short-range repulsion and long-range attraction between solitons. Furthermore, there are many different local energy minima that are all well-described by a simple binary species particle model. In this paper wemore » present the first results on soliton dynamics in the aloof baby Skyrme model. Numerical field theory simulations reveal that the lightly bound cluster structure results in a variety of exotic soliton scattering events that are novel in comparison to standard Skyrmion scattering. A dynamical version of the binary species point particle model is shown to provide a good qualitative description of the dynamics.« less

Bifurcation of solutions to Hamiltonian boundary value problems

NASA Astrophysics Data System (ADS)

McLachlan, R. I.; Offen, C.

2018-06-01

A bifurcation is a qualitative change in a family of solutions to an equation produced by varying parameters. In contrast to the local bifurcations of dynamical systems that are often related to a change in the number or stability of equilibria, bifurcations of boundary value problems are global in nature and may not be related to any obvious change in dynamical behaviour. Catastrophe theory is a well-developed framework which studies the bifurcations of critical points of functions. In this paper we study the bifurcations of solutions of boundary-value problems for symplectic maps, using the language of (finite-dimensional) singularity theory. We associate certain such problems with a geometric picture involving the intersection of Lagrangian submanifolds, and hence with the critical points of a suitable generating function. Within this framework, we then study the effect of three special cases: (i) some common boundary conditions, such as Dirichlet boundary conditions for second-order systems, restrict the possible types of bifurcations (for example, in generic planar systems only the A-series beginning with folds and cusps can occur); (ii) integrable systems, such as planar Hamiltonian systems, can exhibit a novel periodic pitchfork bifurcation; and (iii) systems with Hamiltonian symmetries or reversing symmetries can exhibit restricted bifurcations associated with the symmetry. This approach offers an alternative to the analysis of critical points in function spaces, typically used in the study of bifurcation of variational problems, and opens the way to the detection of more exotic bifurcations than the simple folds and cusps that are often found in examples.

Exotic plant species invade hot spots of native plant diversity

USGS Publications Warehouse

Stohlgren, T.J.; Binkley, Dan; Chong, G.W.; Kalkhan, M.A.; Schell, L.D.; Bull, K.A.; Otsuki, Yuka; Newman, G.; Bashkin, Michael A.; Son, Y.

1999-01-01

Some theories and experimental studies suggest that areas of low plant species richness may be invaded more easily than areas of high plant species richness. We gathered nested-scale vegetation data on plant species richness, foliar cover, and frequency from 200 1-m2 subplots (20 1000-m2 modified-Whittaker plots) in the Colorado Rockies (USA), and 160 1-m2 subplots (16 1000-m2 plots) in the Central Grasslands in Colorado, Wyoming, South Dakota, and Minnesota (USA) to test the generality of this paradigm.At the 1-m2 scale, the paradigm was supported in four prairie types in the Central Grasslands, where exotic species richness declined with increasing plant species richness and cover. At the 1-m2 scale, five forest and meadow vegetation types in the Colorado Rockies contradicted the paradigm; exotic species richness increased with native-plant species richness and foliar cover. At the 1000-m2 plot scale (among vegetation types), 83% of the variance in exotic species richness in the Central Grasslands was explained by the total percentage of nitrogen in the soil and the cover of native plant species. In the Colorado Rockies, 69% of the variance in exotic species richness in 1000-m2 plots was explained by the number of native plant species and the total percentage of soil carbon.At landscape and biome scales, exotic species primarily invaded areas of high species richness in the four Central Grasslands sites and in the five Colorado Rockies vegetation types. For the nine vegetation types in both biomes, exotic species cover was positively correlated with mean foliar cover, mean soil percentage N, and the total number of exotic species. These patterns of invasibility depend on spatial scale, biome and vegetation type, spatial autocorrelation effects, availability of resources, and species-specific responses to grazing and other disturbances. We conclude that: (1) sites high in herbaceous foliar cover and soil fertility, and hot spots of plant diversity (and biodiversity), are invasible in many landscapes; and (2) this pattern may be more closely related to the degree resources are available in native plant communities, independent of species richness. Exotic plant invasions in rare habitats and distinctive plant communities pose a significant challenge to land managers and conservation biologists.

Robust vortex lines, vortex rings, and hopfions in three-dimensional Bose-Einstein condensates

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

Bisset, R. N.; Wang, Wenlong; Ticknor, Christopher

Performing a systematic Bogoliubov–de Gennes spectral analysis, we illustrate that stationary vortex lines, vortex rings, and more exotic states, such as hopfions, are robust in three-dimensional atomic Bose-Einstein condensates, for large parameter intervals. Importantly, we find that the hopfion can be stabilized in a simple parabolic trap, without the need for trap rotation or inhomogeneous interactions. We supplement our spectral analysis by studying the dynamics of such stationary states; we find them to be robust against significant perturbations of the initial state. In the unstable regimes, we not only identify the unstable mode, such as a quadrupolar or hexapolar mode,more » but we also observe the corresponding instability dynamics. Moreover, deep in the Thomas-Fermi regime, we investigate the particlelike behavior of vortex rings and hopfions.« less

Robust vortex lines, vortex rings, and hopfions in three-dimensional Bose-Einstein condensates

DOE PAGES

Bisset, R. N.; Wang, Wenlong; Ticknor, Christopher; ...

2015-12-07

Performing a systematic Bogoliubov–de Gennes spectral analysis, we illustrate that stationary vortex lines, vortex rings, and more exotic states, such as hopfions, are robust in three-dimensional atomic Bose-Einstein condensates, for large parameter intervals. Importantly, we find that the hopfion can be stabilized in a simple parabolic trap, without the need for trap rotation or inhomogeneous interactions. We supplement our spectral analysis by studying the dynamics of such stationary states; we find them to be robust against significant perturbations of the initial state. In the unstable regimes, we not only identify the unstable mode, such as a quadrupolar or hexapolar mode,more » but we also observe the corresponding instability dynamics. Moreover, deep in the Thomas-Fermi regime, we investigate the particlelike behavior of vortex rings and hopfions.« less

Impact of predator dormancy on prey-predator dynamics

NASA Astrophysics Data System (ADS)

Freire, Joana G.; Gallas, Marcia R.; Gallas, Jason A. C.

2018-05-01

The impact of predator dormancy on the population dynamics of phytoplankton-zooplankton in freshwater ecosystems is investigated using a simple model including dormancy, a strategy to avoid extinction. In addition to recently reported chaos-mediated mixed-mode oscillations, as the carrying capacity grows, we find surprisingly wide phases of nonchaos-mediated mixed-mode oscillations to be present well before the onset of chaos in the system. Nonchaos-mediated cascades display spike-adding sequences, while chaos-mediated cascades show spike-doubling. A host of braided periodic phases with exotic shapes is found embedded in a region of control parameters dominated by chaotic oscillations. We describe the organization of these complicated phases and show how they are interconnected and how their complexity unfolds as control parameters change. The novel nonchaos-mediated phases are found to be large and stable, even for low carrying capacity.

9 CFR 352.18 - Cooperation of States in Federal programs.

Code of Federal Regulations, 2010 CFR

2010-01-01

... OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic...

9 CFR 352.11 - Post-mortem inspection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.11 Post...

Experimentally simulating the dynamics of quantum light and matter at ultrastrong coupling using circuit QED (1) - implementation and matter dynamics -

NASA Astrophysics Data System (ADS)

Kounalakis, M.; Langford, N. K.; Sagastizabal, R.; Dickel, C.; Bruno, A.; Luthi, F.; Thoen, D. J.; Endo, A.; Dicarlo, L.

The field dipole coupling of quantum light and matter, described by the quantum Rabi model, leads to exotic phenomena when the coupling strength g becomes comparable or larger than the atom and photon frequencies ωq , r. In this ultra-strong coupling regime, excitations are not conserved, leading to collapse-revival dynamics in atom and photon parity and Schrödinger-cat-like atom-photon entanglement. We realize a quantum simulation of the Rabi model using a transmon qubit coupled to a resonator. In this first part, we describe our analog-digital approach to implement up to 90 symmetric Trotter steps, combining single-qubit gates with the Jaynes-Cummings interaction naturally present in our circuit QED system. Controlling the phase of microwave pulses defines a rotating frame and enables simulation of arbitrary parameter regimes of the Rabi model. We demonstrate measurements of qubit parity dynamics showing revivals at g /ωr > 0 . 8 for ωq = 0 and characteristic dynamics for nondegenerate ωq from g / 4 to g. Funding from the EU FP7 Project ScaleQIT, an ERC Grant, the Dutch Research Organization NWO, and Microsoft Research.

A genetic model based on evapoconcentration for sediment-hosted exotic-Cu mineralization in arid environments: the case of the El Tesoro Central copper deposit, Atacama Desert, Chile

NASA Astrophysics Data System (ADS)

Fernández-Mort, A.; Riquelme, R.; Alonso-Zarza, A. M.; Campos, E.; Bissig, T.; Mpodozis, C.; Carretier, S.; Herrera, C.; Tapia, M.; Pizarro, H.; Muñoz, S.

2017-12-01

Although the formation of exotic-Cu deposits is controlled by multiple factors, the role of the sedimentary environment has not been well defined. We present a case study of the El Tesoro Central exotic-Cu deposit located in the Atacama Desert of northern Chile. This deposit consists of two mineralized bodies hosted within Late Cenozoic gravels deposited in an arid continental environment dominated by alluvial fans with sub-surficial ponded water bodies formed at the foot of these fans or within the interfan areas. Both exotic-Cu orebodies mostly consist of chrysocolla, copper wad, atacamite, paratacamite, quartz, opal, and calcite. The most commonly observed paragenesis comprises chrysocolla, silica minerals, and calcite and records a progressive increase in pH, which is notably influenced by evaporation. The results of stable isotope analyses (δ13C and δ18O) and hydrogeochemical simulations confirm that evapoconcentration is the main controlling factor in the exotic-Cu mineralization at El Tesoro Central. This conclusion complements the traditional genetic model based on the gradual neutralization of highly oversaturated Cu-bearing solutions that progressively cement the gravels and underlying bedrock regardless of the depositional environment. This study concludes that in exotic-Cu deposits formed relatively far from the source, a favorable sedimentary environment and particular hydrologic and climatic conditions are essential to trap, accumulate, evapoconcentrate, neutralize and saturate Cu-bearing solutions to trigger mineralization. Thus, detailed sedimentological studies should be incorporated when devising exploration strategies in order to discover new exotic-Cu resources, particularly if they are expected to have formed relatively far from the metal sources.

Chemical and microbiological changes during vermicomposting of coffee pulp using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis) species.

PubMed

Raphael, Kurian; Velmourougane, K

2011-06-01

Coffee pulp is the main solid residue from the wet processing of coffee berries. Due to presence of anti-physiological and anti-nutritional factors, coffee pulp is not considered as adequate substrate for bioconversion process by coffee farmers. Recent stringent measures by Pollution Control authorities, made it mandatory to treat all the solid and liquid waste emanating from the coffee farms. A study was conducted to evaluate the efficiency of an exotic (Eudrilus eugeniae) and a native earthworm (Perionyx ceylanesis) from coffee farm for decomposition of coffee pulp into valuable vermicompost. Exotic earthworms were found to degrade the coffee pulp faster (112 days) as compared to the native worms (165 days) and the vermicomposting efficiency (77.9%) and vermicompost yield (389 kg) were found to significantly higher with native worms. The multiplication rate of earthworms (280%) and worm yield (3.78 kg) recorded significantly higher with the exotic earthworms. The percentage of nitrogen, phosphorous, potassium, calcium and magnesium in vermicompost was found to increase while C:N ratio, pH and total organic carbon declined as a function of the vermicomposting. The plant nutrients, nitrogen (80.6%), phosphorus (292%) and potassium (550%) content found to increase significantly in the vermicompost produced using native earthworms as compared to the initial values, while the calcium (85.7%) and magnesium (210%) content found to increase significantly in compost produced utilizing exotic worms. Vermicompost and vermicasts from native earthworms recorded significantly higher functional microbial group's population as compared to the exotic worms. The study reveals that coffee pulp can be very well used as substrate for vermicomposting using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis).

Forecasting weed distributions using climate data: a GIS early warning tool

USGS Publications Warehouse

Jarnevich, Catherine S.; Holcombe, Tracy R.; Barnett, David T.; Stohlgren, Thomas J.; Kartesz, John T.

2010-01-01

The number of invasive exotic plant species establishing in the United States is continuing to rise. When prevention of exotic species from entering into a country fails at the national level and the species establishes, reproduces, spreads, and becomes invasive, the most successful action at a local level is early detection followed eradication. We have developed a simple geographic information system (GIS) analysis for developing watch lists for early detection of invasive exotic plants that relies upon currently available species distribution data coupled with environmental data to aid in describing coarse-scale potential distributions. This GIS analysis tool develops environmental envelopes for species based upon the known distribution of a species thought to be invasive and represents the first approximation of its potential habitat while the necessary data are collected to perform more in­-depth analyses. To validate this method we looked at a time series of species distributions for 66 species in Pacific Northwest, and northern Rocky Mountain counties. The time series analysis presented here did select counties that the invasive exotic weeds invaded in subsequent years, showing that this technique could be useful in developing watch lists for the spread of particular exotic species. We applied this same habitat-matching model based upon bioclimaric envelopes to 100 invasive exotics with various levels of known distributions within continental U.S. counties. For species with climatically limited distributions, county watch lists describe county-specific vulnerability to invasion. Species with matching habitats in a county would be added to that county's list. These watch lists can influence management decisions for early warning, control prioritization, and targeted research to determine specific locations within vulnerable counties. This tool provides useful information for rapid assessment of the potential distribution based upon climate envelopes of current distributions for new invasive exotic species.

Role of invasive Melilotus officinalis in two native plant communities

USGS Publications Warehouse

Van Riper, Laura C.; Larson, Diane L.

2009-01-01

This study examines the impact of the exotic nitrogen-fixing legume Melilotus officinalis (L.) Lam. on native and exotic species cover in two Great Plains ecosystems in Badlands National Park, South Dakota. Melilotus is still widely planted and its effects on native ecosystems are not well studied. Melilotus could have direct effects on native plants, such as through competition or facilitation. Alternatively, Melilotus may have indirect effects on natives, e.g., by favoring exotic species which in turn have a negative effect on native species. This study examined these interactions across a 4-year period in two contrasting vegetation types: Badlands sparse vegetation and western wheatgrass (Pascopyrum smithii) mixed-grass prairie. Structural equation models were used to analyze the pathways through which Melilotus, native species, and other exotic species interact over a series of 2-year time steps. Melilotus can affect native and exotic species both in the current year and in the years after its death (a lag effect). A lag effect is possible because the death of a Melilotus plant can leave an open, potentially nitrogen-enriched site on the landscape. The results showed that the relationship between Melilotus and native and exotic species varied depending on the habitat and the year. In Badlands sparse vegetation, there was a consistent, strong, and positive relationship between Melilotus cover and native and exotic species cover suggesting that Melilotus is acting as a nurse plant and facilitating the growth of other species. In contrast, in western wheatgrass prairie, Melilotus was acting as a weak competitor and had no consistent effect on other species. In both habitats, there was little evidence for a direct lag effect of Melilotus on other species. Together, these results suggest both facilitative and competitive roles for Melilotus, depending on the vegetation type it invades.

Exotic Optical Beam Classes for Free-Space Communication

DTIC Science & Technology

2016-03-24

such DISTRIBUTION A: Distribution approved for public release. superoscillations have been shown to be connected with the spacing of zeros in a wave...AFRL-AFOSR-VA-TR-2016-0131 Exotic optical beam classes for free- space communication Greg Gbur UNIVERSITY OF NOTH CAROLINA AT CHARLOTTE Final Report...12-2015 4. TITLE AND SUBTITLE Exotic optical beam classes for free- space communication 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-13-1-0009 5c

Elevated CO2 does not offset greater water stress predicted under climate change for native and exotic riparian plants

USGS Publications Warehouse

Perry, Laura G.; Shafroth, Patrick B.; Blumenthal, Dana M.; Morgan, Jack A.; LeCain, Daniel R.

2013-01-01

In semiarid western North American riparian ecosystems, increased drought and lower streamflows under climate change may reduce plant growth and recruitment, and favor drought-tolerant exotic species over mesic native species. We tested whether elevated atmospheric CO2 might ameliorate these effects by improving plant water-use efficiency. We examined the effects of CO2 and water availability on seedlings of two native (Populus deltoids spp. monilifera, Salix exigua) and three exotic (Elaeagnus angustifolia, Tamarix spp., Ulmus pumila) western North American riparian species in a CO2-controlled glasshouse, using 1-m-deep pots with different water-table decline rates. Low water availability reduced seedling biomass by 70–97%, and hindered the native species more than the exotics. Elevated CO2 increased biomass by 15%, with similar effects on natives and exotics. Elevated CO2 increased intrinsic water-use efficiency (Δ13Cleaf), but did not increase biomass more in drier treatments than wetter treatments. The moderate positive effects of elevated CO2 on riparian seedlings are unlikely to counteract the large negative effects of increased aridity projected under climate change. Our results suggest that increased aridity will reduce riparian seedling growth despite elevated CO2, and will reduce growth more for native Salix and Populus than for drought-tolerant exotic species.

Elevated CO2 does not offset greater water stress predicted under climate change for native and exotic riparian plants

USGS Publications Warehouse

Perry, Laura G.; Shafroth, Patrick B.; Blumenthal, Dana M.; Morgan, Jack A.; LeCain, Daniel R.

2013-01-01

* In semiarid western North American riparian ecosystems, increased drought and lower streamflows under climate change may reduce plant growth and recruitment, and favor drought-tolerant exotic species over mesic native species. We tested whether elevated atmospheric CO2 might ameliorate these effects by improving plant water-use efficiency. * We examined the effects of CO2 and water availability on seedlings of two native (Populus deltoides spp. monilifera, Salix exigua) and three exotic (Elaeagnus angustifolia, Tamarix spp., Ulmus pumila) western North American riparian species in a CO2-controlled glasshouse, using 1-m-deep pots with different water-table decline rates. * Low water availability reduced seedling biomass by 70–97%, and hindered the native species more than the exotics. Elevated CO2 increased biomass by 15%, with similar effects on natives and exotics. Elevated CO2 increased intrinsic water-use efficiency (Δ13Cleaf), but did not increase biomass more in drier treatments than wetter treatments. * The moderate positive effects of elevated CO2 on riparian seedlings are unlikely to counteract the large negative effects of increased aridity projected under climate change. Our results suggest that increased aridity will reduce riparian seedling growth despite elevated CO2, and will reduce growth more for native Salix and Populus than for drought-tolerant exotic species.

Elevated CO₂ does not offset greater water stress predicted under climate change for native and exotic riparian plants.

PubMed

Perry, Laura G; Shafroth, Patrick B; Blumenthal, Dana M; Morgan, Jack A; LeCain, Daniel R

2013-01-01

In semiarid western North American riparian ecosystems, increased drought and lower streamflows under climate change may reduce plant growth and recruitment, and favor drought-tolerant exotic species over mesic native species. We tested whether elevated atmospheric CO₂ might ameliorate these effects by improving plant water-use efficiency. We examined the effects of CO₂ and water availability on seedlings of two native (Populus deltoides spp. monilifera, Salix exigua) and three exotic (Elaeagnus angustifolia, Tamarix spp., Ulmus pumila) western North American riparian species in a CO₂-controlled glasshouse, using 1-m-deep pots with different water-table decline rates. Low water availability reduced seedling biomass by 70-97%, and hindered the native species more than the exotics. Elevated CO₂ increased biomass by 15%, with similar effects on natives and exotics. Elevated CO₂ increased intrinsic water-use efficiency (Δ¹³C(leaf) ), but did not increase biomass more in drier treatments than wetter treatments. The moderate positive effects of elevated CO₂ on riparian seedlings are unlikely to counteract the large negative effects of increased aridity projected under climate change. Our results suggest that increased aridity will reduce riparian seedling growth despite elevated CO₂, and will reduce growth more for native Salix and Populus than for drought-tolerant exotic species. No claim to original US government works. New Phytologist © 2012 New Phytologist Trust.

Exotic decays of the 125 GeV Higgs boson at future e +e – colliders

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

Liu, Zhen; Wang, Lian -Tao; Zhang, Hao

Discovery of unexpected properties of the Higgs boson offers an intriguing opportunity of shedding light on some of the most profound puzzles in particle physics. The Beyond Standard Model (BSM) decays of the Higgs boson could reveal new physics in a direct manner. Future electron-positron lepton colliders operating as Higgs factories, including CEPC, FCC-ee and ILC, with the advantages of a clean collider environment and large statistics, could greatly enhance the sensitivity in searching for these BSM decays. In this work, we perform a general study of Higgs exotic decays at futuremore » $e^+e^-$ lepton colliders, focusing on the Higgs decays with hadronic final states and/or missing energy, which are very challenging for the High-Luminosity program of the Large Hadron Collider (HL-LHC). We show that with simple selection cuts, $$O(10^{-3}\\sim10^{-5})$$ limits on the Higgs exotic decay branching fractions can be achieved using the leptonic decaying spectator $Z$ boson in the associated production mode $$e^+e^-\\rightarrow Z H$$. We further discuss the interplay between the detector performance and Higgs exotic decay, and other possibilities of exotic decays. Finally, our work is a first step in a comprehensive study of Higgs exotic decays at future lepton colliders, which is a key ingredient of Higgs physics that deserves further investigation.« less

Tevatron constraints on models of the Higgs boson with exotic spin and parity using decays to bottom-antibottom quark pairs

DOE PAGES

Aaltonen, T.

2015-04-15

In this study, combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin J and parity P are presented and compared with results obtained assuming the standard model value J P = 0 +. Both collaborations analyzed approximately 10 fb –1 of proton-antiproton collisions with a center-of-mass energy of 1.96 TeV collected at the Fermilab Tevatron. Two models predicting exotic Higgs bosons with J P = 0 – and J P = 2 + are tested. The kinematic properties of exotic Higgs boson production in association with a vector boson differ from thosemore » predicted for the standard model Higgs boson. Upper limits at the 95% credibility level on the production rates of the exotic Higgs bosons, expressed as fractions of the standard model Higgs boson production rate, are set at 0.36 for both the J P = 0 – hypothesis and the J P = 2 + hypothesis. If the production rate times the branching ratio to a bottom-antibottom pair is the same as that predicted for the standard model Higgs boson, then the exotic bosons are excluded with significances of 5.0 standard deviations and 4.9 standard deviations for the J P = 0 – and J P = 2 + hypotheses, respectively.« less

Native fauna on exotic trees: phylogenetic conservatism and geographic contingency in two lineages of phytophages on two lineages of trees.

PubMed

Gossner, Martin M; Chao, Anne; Bailey, Richard I; Prinzing, Andreas

2009-05-01

The relative roles of evolutionary history and geographical and ecological contingency for community assembly remain unknown. Plant species, for instance, share more phytophages with closer relatives (phylogenetic conservatism), but for exotic plants introduced to another continent, this may be overlaid by geographically contingent evolution or immigration from locally abundant plant species (mass effects). We assessed within local forests to what extent exotic trees (Douglas-fir, red oak) recruit phytophages (Coleoptera, Heteroptera) from more closely or more distantly related native plants. We found that exotics shared more phytophages with natives from the same major plant lineage (angiosperms vs. gymnosperms) than with natives from the other lineage. This was particularly true for Heteroptera, and it emphasizes the role of host specialization in phylogenetic conservatism of host use. However, for Coleoptera on Douglas-fir, mass effects were important: immigration from beech increased with increasing beech abundance. Within a plant phylum, phylogenetic proximity of exotics and natives increased phytophage similarity, primarily in younger Coleoptera clades on angiosperms, emphasizing a role of past codiversification of hosts and phytophages. Overall, phylogenetic conservatism can shape the assembly of local phytophage communities on exotic trees. Whether it outweighs geographic contingency and mass effects depends on the interplay of phylogenetic scale, local abundance of native tree species, and the biology and evolutionary history of the phytophage taxon.

The Influence of Exotic Lady Beetle (Coleoptera: Coccinellidae) Establishment on the Species Composition of the Native Lady Beetle Community in Missouri.

PubMed

Diepenbrock, Lauren M; Fothergill, Kent; Tindall, Kelly V; Losey, John E; Smyth, Rebecca R; Finke, Deborah L

2016-08-01

The diversity and abundance of native lady beetles (Coccinellidae) in North America has declined in recent decades. This decline is often correlated with the introduction and establishment of exotic lady beetle species, including Coccinella septempunctata L. and Harmonia axyridis Pallas, suggesting that exotic species precipitated the decline of native lady beetles. We examined species records of native coccinellids in Missouri over 118 yr and asked whether the species composition of the community experienced a shift following the establishment of the exotic species. We found that the contemporary native coccinellid community is different from the community that was present nearly a century ago. However, there was no evidence for a recent abrupt shift in composition triggered by the establishment of exotic species. Instead, our data suggest that the native lady beetle community has been undergoing consistent and gradual change over time, with some species decreasing in abundance and others increasing. While not excluding exotic species as a factor contributing to the decline of native lady beetle species, our findings suggest that other continuous factors, like land use change, may have played a more influential role in determining the composition of the native coccinellid communities within our region. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Exotic decays of the 125 GeV Higgs boson at future e +e – colliders

DOE PAGES

Liu, Zhen; Wang, Lian -Tao; Zhang, Hao

2017-06-01

Discovery of unexpected properties of the Higgs boson offers an intriguing opportunity of shedding light on some of the most profound puzzles in particle physics. The Beyond Standard Model (BSM) decays of the Higgs boson could reveal new physics in a direct manner. Future electron-positron lepton colliders operating as Higgs factories, including CEPC, FCC-ee and ILC, with the advantages of a clean collider environment and large statistics, could greatly enhance the sensitivity in searching for these BSM decays. In this work, we perform a general study of Higgs exotic decays at futuremore » $e^+e^-$ lepton colliders, focusing on the Higgs decays with hadronic final states and/or missing energy, which are very challenging for the High-Luminosity program of the Large Hadron Collider (HL-LHC). We show that with simple selection cuts, $$O(10^{-3}\\sim10^{-5})$$ limits on the Higgs exotic decay branching fractions can be achieved using the leptonic decaying spectator $Z$ boson in the associated production mode $$e^+e^-\\rightarrow Z H$$. We further discuss the interplay between the detector performance and Higgs exotic decay, and other possibilities of exotic decays. Finally, our work is a first step in a comprehensive study of Higgs exotic decays at future lepton colliders, which is a key ingredient of Higgs physics that deserves further investigation.« less

Allopatric integrations selectively change host transcriptomes, leading to varied expression efficiencies of exotic genes in Myxococcus xanthus.

PubMed

Zhu, Li-Ping; Yue, Xin-Jing; Han, Kui; Li, Zhi-Feng; Zheng, Lian-Shuai; Yi, Xiu-Nan; Wang, Hai-Long; Zhang, You-Ming; Li, Yue-Zhong

2015-07-22

Exotic genes, especially clustered multiple-genes for a complex pathway, are normally integrated into chromosome for heterologous expression. The influences of insertion sites on heterologous expression and allotropic expressions of exotic genes on host remain mostly unclear. We compared the integration and expression efficiencies of single and multiple exotic genes that were inserted into Myxococcus xanthus genome by transposition and attB-site-directed recombination. While the site-directed integration had a rather stable chloramphenicol acetyl transferase (CAT) activity, the transposition produced varied CAT enzyme activities. We attempted to integrate the 56-kb gene cluster for the biosynthesis of antitumor polyketides epothilones into M. xanthus genome by site-direction but failed, which was determined to be due to the insertion size limitation at the attB site. The transposition technique produced many recombinants with varied production capabilities of epothilones, which, however, were not paralleled to the transcriptional characteristics of the local sites where the genes were integrated. Comparative transcriptomics analysis demonstrated that the allopatric integrations caused selective changes of host transcriptomes, leading to varied expressions of epothilone genes in different mutants. With the increase of insertion fragment size, transposition is a more practicable integration method for the expression of exotic genes. Allopatric integrations selectively change host transcriptomes, which lead to varied expression efficiencies of exotic genes.

Search for the Photoexcitation of Exotic Mesons in the π+π+π- System

NASA Astrophysics Data System (ADS)

Nozar, M.; Salgado, C.; Weygand, D. P.; Guo, L.; Adams, G.; Li, Ji; Eugenio, P.; Amaryan, M. J.; Anghinolfi, M.; Asryan, G.; Avakian, H.; Bagdasaryan, H.; Baillie, N.; Ball, J. P.; Baltzell, N. A.; Barrow, S.; Battaglieri, M.; Bedlinskiy, I.; Bektasoglu, M.; Bellis, M.; Benmouna, N.; Berman, B. L.; Biselli, A. S.; Blaszczyk, L.; Bonner, B. E.; Bouchigny, S.; Boiarinov, S.; Bradford, R.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Bültmann, S.; Burkert, V. D.; Butuceanu, C.; Calarco, J. R.; Careccia, S. L.; Carman, D. S.; Carnahan, B.; Casey, L.; Cazes, A.; Chen, S.; Cheng, L.; Cole, P. L.; Collins, P.; Coltharp, P.; Cords, D.; Corvisiero, P.; Crabb, D.; Crannell, H.; Crede, V.; Cummings, J. P.; Dale, D.; Dashyan, N.; de Masi, R.; de Vita, R.; de Sanctis, E.; Degtyarenko, P. V.; Denizli, H.; Dennis, L.; Deur, A.; Dharmawardane, K. V.; Dhuga, K. S.; Dickson, R.; Djalali, C.; Dodge, G. E.; Doughty, D.; Dugger, M.; Dytman, S.; Dzyubak, O. P.; Egiyan, H.; Egiyan, K. S.; El Fassi, L.; Elouadrhiri, L.; Fatemi, R.; Fedotov, G.; Feuerbach, R. J.; Forest, T. A.; Fradi, A.; Funsten, H.; Garçon, M.; Gavalian, G.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guillo, M.; Guler, N.; Gyurjyan, V.; Hadjidakis, C.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Hardie, J.; Hassall, N.; Heddle, D.; Hersman, F. W.; Hicks, K.; Hleiqawi, I.; Holtrop, M.; Hyde-Wright, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Ito, M. M.; Jenkins, D.; Jo, H. S.; Johnstone, J. R.; Joo, K.; Juengst, H. G.; Kalantarians, N.; Kellie, J. D.; Khandaker, M.; Kim, W.; Klein, A.; Klein, F. J.; Kossov, M.; Krahn, Z.; Kramer, L. H.; Kubarovsky, V.; Kuhn, J.; Kuhn, S. E.; Kuleshov, S. V.; Kuznetsov, V.; Lachniet, J.; Laget, J. M.; Langheinrich, J.; Lawrence, D.; Livingston, K.; Lu, H. Y.; MacCormick, M.; Markov, N.; Mattione, P.; McAleer, S.; McKinnon, B.; McNabb, J. W. C.; Mecking, B. A.; Mehrabyan, S.; Mestayer, M. D.; Meyer, C. A.; Mibe, T.; Mikhailov, K.; Mirazita, M.; Miskimen, R.; Mokeev, V.; Moreno, B.; Moriya, K.; Morrow, S. A.; Moteabbed, M.; Mueller, J.; Munevar, E.; Mutchler, G. S.; Nadel-Turonski, P.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niczyporuk, B. B.; Niroula, M. R.; Niyazov, R. A.; O'Rielly, G. V.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Paterson, C.; Anefalos Pereira, S.; Philips, S. A.; Pierce, J.; Pivnyuk, N.; Pocanic, D.; Pogorelko, O.; Polli, E.; Popa, I.; Pozdniakov, S.; Preedom, B. M.; Price, J. W.; Prok, Y.; Protopopescu, D.; Qin, L. M.; Raue, B. A.; Riccardi, G.; Ricco, G.; Ripani, M.; Ritchie, B. G.; Ronchetti, F.; Rosner, G.; Rossi, P.; Rubin, P. D.; Sabatié, F.; Salamanca, J.; Santoro, J. P.; Sapunenko, V.; Schumacher, R. A.; Serov, V. S.; Sharabian, Y. G.; Sharov, D.; Shvedunov, N. V.; Skabelin, A. V.; Smith, E. S.; Smith, L. C.; Sober, D. I.; Sokhan, D.; Stavinsky, A.; Stepanyan, S. S.; Stepanyan, S.; Stokes, B. E.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Tedeschi, D. J.; Thoma, U.; Tkabladze, A.; Tkachenko, S.; Todor, L.; Ungaro, M.; Vineyard, M. F.; Vlassov, A. V.; Watts, D. P.; Weinstein, L. B.; Williams, M.; Wolin, E.; Wood, M. H.; Yegneswaran, A.; Zana, L.; Zhang, J.; Zhao, B.; Zhao, Z. W.

2009-03-01

A search for exotic mesons in the π+π+π- system photoproduced by the charge exchange reaction γp→π+π+π-(n) was carried out by the CLAS Collaboration at Jefferson Lab. A tagged-photon beam with energies in the 4.8 to 5.4 GeV range, produced through bremsstrahlung from a 5.744 GeV electron beam, was incident on a liquid-hydrogen target. A partial wave analysis was performed on a sample of 83 000 events, the highest such statistics to date in this reaction at these energies. The main objective of this study was to look for the photoproduction of an exotic JPC=1-+ resonant state in the 1 to 2 GeV mass range. Our partial wave analysis shows production of the a2(1320) and the π2(1670) mesons, but no evidence for the a1(1260), nor the π1(1600) exotic state at the expected levels. An upper limit of 13.5 nb is determined for the exotic π1(1600) cross section, less than 2% of the a2(1320) production.

U.S. federal policies, legislation, and responsibilities related to importation of exotic fishes and other aquatic organisms

USGS Publications Warehouse

Stanley, Jon G.; Peoples, Robert A.; McCann, James A.

1991-01-01

Within the Federal government, the U. S. Fish and Wildlife Service (Service) has primary responsibility for legal and policy responsibility for introduced exotic species. The Lacey Act of 1900 authorizes the Service to prohibit the importation of species that are potentially injurious to native fish and wildlife. However, regulations under authority of the Lacey Act cover only a few species. The Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 established a Task Force co-chaired by the Director of the Service and Under Secretary of Commerce for Oceans and Atmosphere. The Task Force consults with the Secretary of Transportation to develop regulations to prevent the importation and spread of aquatic nuisance species into the Great Lakes through exchange of ballast water. Federal agencies must comply with Presidential Executive Order 1198, Exotic Organisms, that prohibits Federal agencies or activities they fund or authorize from introducing exotic species. The Service conducts research and evaluation of exotic species to support Federal, State, and local efforts to prevent further importation of harmful species. Effective regulation will also depend on the full cooperation with Canada.

Parasites of native and exotic freshwater fishes in south-western Australia.

PubMed

Lymbery, A J; Hassan, M; Morgan, D L; Beatty, S J; Doupé, R G

2010-05-01

In this study, 1429 fishes of 18 different species (12 native and six exotic) were sampled from 29 localities to compare the levels of parasitism between native and exotic fish species and to examine the relationship between environmental degradation and parasite diversity. Forty-four putative species of parasites were found and most of these appear to be native parasites, which have not previously been described. Two parasite species, Lernaea cyprinacea and Ligula intestinalis, are probably introduced. Both were found on or in a range of native fish species, where they may cause severe disease. Levels of parasitism and parasite diversity were significantly greater in native fishes than in exotic species, and this may contribute to an enhanced demographic performance and competitive ability in invading exotics. Levels of parasitism and parasite diversity in native fishes were negatively related to habitat disturbance, in particular to a suite of factors that indicate increased human use of the river and surrounding environment. This was due principally to the absence in more disturbed habitats of a number of species of endoparasites with complex life cycles, involving transmission between different host species.

9 CFR 352.15 - Records, registration, and reports.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.15 Records...

9 CFR 352.9 - Report of inspection work.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.9 Report of...

[Cynocephali and Blemmyae. Congenital anomalies and medieval exotic races].

PubMed

Bos, C A; Baljet, B

1999-12-18

In the mediaeval Dutch manuscript Der naturen bloeme ('On the flowers of nature') by Jacob van Maerlant (circa 1230-circa 1296), an encyclopaedia of descriptions of people, animals, plants and minerals dating from about 1270, many illustrations refer to the text. An intriguing part of the book is called 'Vreemde volkeren' ('Exotic people'). In another manuscript of Van Maerlant, Dit is die istory van Troyen ('The history of Troyes') in the chapter 'De wonderen van het Verre Oosten' ('The miracles of the Far East') the exotic people are also described. These exotic people have many features similar to congenital malformations. 'Hippopodes' are probably based on the lobster claw syndrome, 'Cynocephali' on anencephaly, 'Arimaspi' on cyclopia, 'Blemmyae' on acardiacus, the double-faced on diprosopus, 'Sciopods' on polydactyly and 'Antipodes' on the sirenomelia sequence.

Exotic Superconductivity in Correlated Electron Systems

DOE PAGES

Mu, Gang; Sandu, Viorel; Li, Wei; ...

2015-05-25

Over the past decades, the search for high-T c superconductivity (SC) and its novel superconducting mechanisms is one of the most challenging tasks of condensed matter physicists and material scientists, wherein the most striking achievement is the discovery of high- c and unconventional superconductivity in strongly correlated 3d-electron systems, such as cuprates and iron pnictides/chalcogenides. Those exotic superconductors display the behaviors beyond the scope of the BCS theory (in the SC states) and the Landau-Fermi liquid theory (in the normal states). In general, such exotic superconductivity can be seen as correlated electron systems, where there are strong interplays among charge,more » spin, orbital, and lattice degrees of freedom. Thus, we focus on the exotic superconductivity in materials with correlated electrons in the present special issue.« less

Wildlife, Exotic Pets, and Emerging Zoonoses1

PubMed Central

Belotto, Albino; Meslin, François-Xavier

2007-01-01

Most emerging infectious diseases are zoonotic; wildlife constitutes a large and often unknown reservoir. Wildlife can also be a source for reemergence of previously controlled zoonoses. Although the discovery of such zoonoses is often related to better diagnostic tools, the leading causes of their emergence are human behavior and modifications to natural habitats (expansion of human populations and their encroachment on wildlife habitat), changes in agricultural practices, and globalization of trade. However, other factors include wildlife trade and translocation, live animal and bushmeat markets, consumption of exotic foods, development of ecotourism, access to petting zoos, and ownership of exotic pets. To reduce risk for emerging zoonoses, the public should be educated about the risks associated with wildlife, bushmeat, and exotic pet trades; and proper surveillance systems should be implemented. PMID:17370509

Physical considerations relevant to HZE-particle transport in matter.

PubMed

Schimmerling, W

1988-06-01

High-energy, highly charged (HZE) heavy nuclei may seem at first sight to be an exotic type of radiation, only remotely connected with nuclear power generation. On closer examination it becomes evident that heavy-ion accelerators are being seriously considered for driving inertial confinement fusion reactors, and high-energy heavy nuclei in the cosmic radiation are likely to place significant constraints on satellite power system deployment and space-based power generation. The use of beams of heavy nuclei in an increasing number of current applications, as well as their importance for the development of the state of the art of the future, makes it necessary to develop at the same time a good understanding of their transport through matter.

Meson Spectroscopy in the Light Quark Sector

NASA Astrophysics Data System (ADS)

De Vita, R.

2014-03-01

Understanding the hadron spectrum is one of the fundamental issues in modern particle physics. We know that existing hadron configurations include baryons, made of three quarks, and mesons, made of quark-antiquark pairs. However most of the mass of the hadrons is not due to the mass of these elementary constituents but to their binding force. Studying the hadron spectrum is therefore a tool to understand one of the fundamental forces in nature, the strong force, and Quantum Chromo Dynamics (QCD), the theory that describes it. This investigation can provide an answer to fundamental questions as what is the origin of the mass of hadrons, what is the origin of quark confinement, what are the relevant degrees of freedom to describe these complex systems and how the transition between the elementary constituents, quarks and gluons, and baryons and mesons occurs. In this field a key tool is given by meson spectroscopy. Mesons, being made by a quark and an anti-quark, are the simplest quark bound system and therefore the ideal benchmark to study the interaction between quarks and understand what the role of gluons is. In this investigation, it is fundamental to precisely determine the spectrum and properties of mesons but also to search for possible unconventional states beyond the qbar q configuration as tetraquarks (qqoverline{qq}), hybrids (qbar qg) and glueballs. These states can be distinguished unambiguously from regular mesons when they have exotic quantum numbers, i.e. combinations of total angular momentum, spin and parity that are not allowed for qbar q states. These are called exotic quantum numbers and the corresponding states are referred to as exotics. The study of the meson spectrum and the search for exotics is among the goals of several experiments in the world that exploit different reaction processes, as e+e- annihilation, pbar p annihilation, pion scattering, proton-proton scattering and photo-production, to produce meson states. This intense effort is leading to a very rich phenomenology in this sector and, together with recent theoretical progress achieved with lattice QCD calculations, is providing crucial information to reach a deeper understanding of strong interaction. In these proceedings I will review the present status of meson spectroscopy in the light quark sector and the plans and perspectives for future experiments.

9 CFR 352.5 - Fees and charges.

Code of Federal Regulations, 2010 CFR

2010-01-01

... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.5 Fees and charges. (a) Fees...

Wormholes in Einstein-Born-Infeld Gravity

NASA Astrophysics Data System (ADS)

Kim, Jin Young; Park, Mu-In

2018-01-01

We introduce a new approach to construct wormholes without introducing exotic matters in Einstein-Born-Infeld gravity with a cosmological constant. Contary to the conventional approach, the throat is located at the place where the solutions can be joined smoothly. The metric and its derivatives are continuous so that the exotic matters are not needed there. The exoticity of the energy-momentum tensor is not essential to sustain the wormhole. We also present a method to check the stability of wormholes in the new approach.

Exotic geophysical phenomena observed in an environmental neutron flux study using EAS PRISMA detectors

NASA Astrophysics Data System (ADS)

Alekseenko, Victor; Bagrova, Anastasia; Cui, Shuwang; He, Yayun; Li, Bingbing; Ma, Xinhua; Pozdnyakov, Egor; Shchegolev, Oleg; Stenkin, Yuri; Stepanov, Vladimir

2017-06-01

Some exotic geophysical events are observed by a global net of electron-neutron detectors (en-detectors) developed in the framework of the PRISMA EAS project. Our en-detectors running both on the Earth's surface and underground are continuously measuring the environmental thermal neutron flux. Thermal neutrons are in equilibrium with media and are therefore sensitive to many geophysical phenomena, which are exotic for people studying ultra high-energy cosmic rays or carrying out low background experiments deep underground.

Discovery of an Exotic Population of Thereuonema tuberculata (Chilopoda:Scutigeromorpha), the Japanese House Centipede, in Ohio, U.S.A.

DTIC Science & Technology

2017-02-28

Journal Article 3. DATES COVERED (From – To) April 2011 – May 2016 4. TITLE AND SUBTITLE Discovery of an Exotic Population of Thereuonema...North America and is recognized as the only scutigeromorph in most of the United States and Canada. I report on the discovery of a population of the...2017) 177:162–164 Notes and Discussion Piece Discovery of an Exotic Population of Thereuonema tuberculata (Chilopoda: Scutigeromorpha), the Japanese

9 CFR 352.4 - Application for ante-mortem inspection service in the field.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic...

Assessing exotic plant species invasions and associated soil characteristics: A case study in eastern Rocky Mountain National Park, Colorado, USA, using the pixel nested plot design

USGS Publications Warehouse

Kalkhan, M.A.; Stafford, E.J.; Woodly, P.J.; Stohlgren, T.J.

2007-01-01

Rocky Mountain National Park (RMNP), Colorado, USA, contains a diversity of plant species. However, many exotic plant species have become established, potentially impacting the structure and function of native plant communities. Our goal was to quantify patterns of exotic plant species in relation to native plant species, soil characteristics, and other abiotic factors that may indicate or predict their establishment and success. Our research approach for field data collection was based on a field plot design called the pixel nested plot. The pixel nested plot provides a link to multi-phase and multi-scale spatial modeling-mapping techniques that can be used to estimate total species richness and patterns of plant diversity at finer landscape scales. Within the eastern region of RMNP, in an area of approximately 35,000 ha, we established a total of 60 pixel nested plots in 9 vegetation types. We used canonical correspondence analysis (CCA) and multiple linear regressions to quantify relationships between soil characteristics and native and exotic plant species richness and cover. We also used linear correlation, spatial autocorrelation and cross correlation statistics to test for the spatial patterns of variables of interest. CCA showed that exotic species were significantly (P < 0.05) associated with photosynthetically active radiation (r = 0.55), soil nitrogen (r = 0.58) and bare ground (r = -0.66). Pearson's correlation statistic showed significant linear relationships between exotic species, organic carbon, soil nitrogen, and bare ground. While spatial autocorrelations indicated that our 60 pixel nested plots were spatially independent, the cross correlation statistics indicated that exotic plant species were spatially associated with bare ground, in general, exotic plant species were most abundant in areas of high native species richness. This indicates that resource managers should focus on the protection of relatively rare native rich sites with little canopy cover, and fertile soils. Using the pixel nested plot approach for data collection can facilitate the ecological monitoring of these vulnerable areas at the landscape scale in a time- and cost-effective manner. ?? 2006 Elsevier B.V. All rights reserved.

Review on structured optical field generated from array beams

NASA Astrophysics Data System (ADS)

Hou, Tianyue; Zhou, Pu; Ma, Yanxing; Zhi, Dong

2018-03-01

Structured optical field (SOF), which includes vortex beams, non-diffraction beams, cylindrical vector beams and so on, has been under intensive investigation theoretically and experimentally in recent years. Generally, current research focus on the extraordinary properties (non-diffraction propagation, helical wavefront, rotation of electrical field, et al), which can be widely applied in micro-particle manipulation, super-resolution imaging, free-space communication and so on. There are mainly two technical routes, that is, inner-cavity and outer-cavity (spatial light modulators, diffractive phase holograms, q-plates). To date, most of the SOFs generated from both technical routes involves with single monolithic beam. As a novel technical route, SOF based on array beams has the advantage in more flexible freedom degree and power scaling potential. In this paper, research achievements in SOF generation based on array beams are arranged and discussed in detail. Moreover, experiment of generating exotic beam by array beams is introduced, which illustrates that SOF generated from array beams is theoretically valid and experimentally feasible. SOF generated from array beams is also beneficial for capacity increasing and data receiving for free-space optical communication systems at long distance.

Reaction dynamics studies for the system 7Be+58Ni

NASA Astrophysics Data System (ADS)

Torresi, D.; Mazzocco, M.; Acosta, L.; Boiano, A.; Boiano, C.; Diaz-Torres, A.; Fierro, N.; Glodariu, T.; Grilj, L.; Guglielmetti, A.; Keeley, N.; La Commara, M.; Martel, I.; Mazzocchi, C.; Molini, P.; Pakou, A.; Parascandolo, C.; Parkar, V. V.; Patronis, N.; Pierroutsakou, D.; Romoli, M.; Rusek, K.; Sanchez-Benitez, A. M.; Sandoli, M.; Signorini, C.; Silvestri, R.; Soramel, F.; Stiliaris, E.; Strano, E.; Stroe, L.; Zerva, K.

2015-04-01

The study of reactions induced by exotic weakly bound nuclei at energies around the Coulomb barrier had attracted a large interest in the last decade, since the features of these nuclei can deeply affect the reaction dynamics. The discrimination between different reaction mechanisms is, in general, a rather difficult task. It can be achieved by using detector arrays covering high solid angle and with high granularity that allow to measure the reaction products and, possibly, coincidences between them, as, for example, recently done for stable weakly bound nuclei [1, 2]. We investigated the collision of the weakly bound nucleus 7Be on a 58Ni target at the beam energy of 1.1 times the Coulomb barrier, measuring the elastic scattering angular distribution and the energy and angular distributions of 3He and 4He. The 7Be radioactive ion beam was produced by the facility EXOTIC at INFN-LNL with an energy of 22 MeV and an intensity of ~3×105 pps. Results showed that the 4He yeld is about 4 times larger than 3He yield, suggesting that reaction mechanisms other than the break-up mostly produce the He isotopes. Theoretical calculations for transfer channels and compound nucleus reactions suggest that complete fusion accounts for (41±5%) of the total reaction cross section extracted from optical model analysis of the elastic scattering data, and that 3He and 4He stripping are the most populated reaction channels among direct processes. Eventually estimation of incomplete fusion contributions to the 3,4He production cross sections was performed through semi-classical calculations with the code PLATYPUS [3].

Using Lasers and X-rays to Reveal the Motion of Atoms and Electrons (LBNL Summer Lecture Series)

ScienceCinema

Schoenlein, Robert [Deputy Director, Advanced Light Source

2017-12-09

Summer Lecture Series 2009: The ultrafast motion of atoms and electrons lies at the heart of chemical reactions, advanced materials with exotic properties, and biological processes such as the first event in vision. Bob Schoenlein, Deputy Director for Science at the Advanced Light Source, will discuss how such processes are revealed by using laser pulses spanning a millionth of a billionth of a second, and how a new generation of light sources will bring the penetrating power of x-rays to the world of ultrafast science.

KIP THORNE: The Shaman of Space and Time.

PubMed

Irion, R

2000-11-24

A generation of physicists probing the extremes of gravity can trace its scientific heritage to one man: Kip Thorne of the California Institute of Technology. A recent symposium to mark Thorne's 60th birthday brought together nearly 200 experts on gravity at its strongest and strangest: the domains of black holes, colliding neutron stars, and other exotic deep-space objects. Participants came to honor their mentor, who has led the way in converting Albert Einstein's General Theory of Relativity from a purely theoretical science into an astrophysical and observational one.

Using Lasers and X-rays to Reveal the Motion of Atoms and Electrons (LBNL Summer Lecture Series)

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

Schoenlein, Robert

2009-07-07

Summer Lecture Series 2009: The ultrafast motion of atoms and electrons lies at the heart of chemical reactions, advanced materials with exotic properties, and biological processes such as the first event in vision. Bob Schoenlein, Deputy Director for Science at the Advanced Light Source, will discuss how such processes are revealed by using laser pulses spanning a millionth of a billionth of a second, and how a new generation of light sources will bring the penetrating power of x-rays to the world of ultrafast science.

Evolution of Structure in Nuclei: Meditation by Sub-Shell Modifications and Relation to Binding Energies

NASA Astrophysics Data System (ADS)

Casten, R. F.; Cakirli, R. B.

2009-03-01

Understanding the development of configuration mixing, coherence, collectivity, and deformation in nuclei is one of the crucial challenges in nuclear structure physics, and one which has become all the more important with the advent of next generation facilities for the study of exotic nuclei. We will discuss recent work on phase/shape transitional behavior in nuclei, and the role of changes in sub-shell structure in mediating such transitional regions. We will also discuss a newly found, much deeper, link between nuclear structure and nuclear binding energies.

Using Lasers and X-rays to Reveal the Motion of Atoms and Electrons (LBNL Summer Lecture Series)

ScienceCinema

Schoenlein, Robert [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS), Materials Sciences Division and Chemical Sciences Division

2018-05-07

Summer Lecture Series 2009: The ultrafast motion of atoms and electrons lies at the heart of chemical reactions, advanced materials with exotic properties, and biological processes such as the first event in vision. Bob Schoenlein, Deputy Director for Science at the Advanced Light Source, will discuss how such processes are revealed by using laser pulses spanning a millionth of a billionth of a second, and how a new generation of light sources will bring the penetrating power of x-rays to the world of ultrafast science.

Gravitational Wave Signatures of Crystalline Color Superconductors

NASA Astrophysics Data System (ADS)

Lin, Lap-Ming

Deconfined quark matter may exist in a crystalline color-superconducing phase in the interiors of compact stars. One of the special properties of this exotic phase of matter is that it is extremely rigid and the corresponding shear modulus can be up to 1000 times larger than that of the neutron-star crust. In this paper, we review how the extreme rigidity of this crystalline phase of quark matter can lead to unique gravitational-wave signatures that may be detectable by the current or the next-generation gravitational-wave detectors.

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

Flores-Tlalpa, A.; Montano, J.; Ramirez-Zavaleta, F.

The one-loop induced Z{yields}gg{gamma} and Z{sup '}{yields}gg{gamma} decays are studied within the context of the minimal 331 model, which predicts the existence of new gauge bosons and three exotic quarks. It is found that the Z{yields}gg{gamma} decay is insensitive to the presence of the exotic quarks, as it is essentially governed by the first two families of known quarks. As to the Z{sup '}{yields}gg{gamma} decay, it is found that the exotic quark contribution dominates and that for a heavy Z{sup '} boson it leads to a {gamma}(Z{sup '}{yields}gg{gamma}) that is more than 1 order of magnitude larger than that associatedmore » with {gamma}(Z{sup '}{yields}ggg). This result may be used to distinguish a new neutral Z{sup '} boson from those models that do not introduce exotic quarks.« less

Higgs exotic decays in general NMSSM with self-interacting dark matter

NASA Astrophysics Data System (ADS)

Wang, Wenyu; Zhang, Mengchao; Zhao, Jun

2018-04-01

Under current LHC and dark matter constraints, the general NMSSM can have self-interacting dark matter to explain the cosmological small structure. In this scenario, the dark matter is the light singlino-like neutralino (χ) which self-interacts through exchanging the light singlet-like scalars (h1,a1). These light scalars and neutralinos inevitably interact with the 125 GeV SM-like Higgs boson (hSM), which cause the Higgs exotic decays hSM → h1h1, a1a1, χχ. We first demonstrate the parameter space required by the explanation of the cosmological small structure and then display the Higgs exotic decays. We find that in such a parameter space the Higgs exotic decays can have branching ratios of a few percent, which should be accessible in the future e+e‑ colliders.

Injuries, envenomations and stings from exotic pets

PubMed Central

Warwick, Clifford; Steedman, Catrina

2012-01-01

A variety of exotic vertebrate and invertebrate species are kept as ‘pets’ including fishes, amphibians (for example, frogs and toads), reptiles (turtles, crocodiles, lizards and snakes), birds, mammals (for example, primates, civets, and lions), and invertebrates (for example spiders, scorpions, and centipedes), and ownership of some of these animals is rising. Data for 2009–2011 suggest that the number of homes with reptiles rose by approximately 12.5%. Recent surveys, including only some of these animals, indicated that they might be present in around 18.6% of homes (equal to approximately 42 million animals of which around 40 million are indoor or outdoor fish). Many exotic ‘pets’ are capable of causing injury or poisoning to their keepers and some contacts prove fatal. We examined NHS Health Episode Statistics for England using selected formal categories for hospital admissions and bed days for 2004–2010 using the following categories of injury, envenomation or sting; bitten or struck by crocodile or alligator; bitten or crushed by other reptiles: contact with venomous snakes and lizards; contact with scorpions. Between 2004 and 2010 these data conservatively show a total of 760 full consultation episodes, 709 admissions and 2,121 hospital bed days were associated with injuries probably from exotic pets. Injuries, envenomations and stings from exotic pets constitute a small but important component of emerging medical problems. Greater awareness of relevant injuries and medical sequelae from exotic pet keeping may help medics formulate their clinical assessment and advice to patients. PMID:22843648

Potential use of random amplified polymorphic DNA (RAPD) technique to study the genetic diversity in Indian mustard (Brassica juncea) and its relationship to heterosis.

PubMed

Jain, A; Bhatia, S; Banga, S S; Prakash, S; Lakshmikumaran, M

1994-04-01

RAPD assays were performed, using 34 arbitrary decamer oligonucleotide primers and six combinations of two primers, to detect inherent variations and genetic relationships among 12 Indian and 11 exotic B. juncea genotypes. Of 595 amplification products identified, 500 of them were polymorphic across all genotypes. A low level of genetic variability was detected among the Indian genotypes, while considerable polymorphism was present among the exotic ones. Based on the pair-wise comparisons of amplification products the genetic similarity was calculated using Jaccard's similarity coefficients and a dendrogram was constructed using an unweighted pair group method was arithmetical averages (UPGMA). On the basis of this analysis the genotypes were clustered into two groups, A and B. Group A comprised only exotic genotypes, whereas all the Indian genotypes and four of the exotic genotypes were clustered in group B. Almost similar genotypic rankings could also be established by computing as few as 200 amplification products. In general, a high per cent of heterosis was recorded in crosses involving Indian x exotic genotypes. On the other hand, when crosses were made amongst Indian or exotic genotypes, about 80% of them exhibited negative heterosis. Results from this study indicate that, despite the lack of direct correlation between the genetic distance and the degree of heterosis, genetic diversity forms a very useful guide not only for investigating the relationships among Brassica genotypes but also in the selection of parents for heterotic hybrid combinations.

Deciphering the "chemical" nature of the exotic isotopes of hydrogen by the MC-QTAIM analysis: the positively charged muon and the muonic helium as new members of the periodic table.

PubMed

Goli, Mohammad; Shahbazian, Shant

2014-04-14

This report is a primarily survey on the chemical nature of some exotic species containing the positively charged muon and the muonic helium, i.e., the negatively charged muon plus helium nucleus, as exotic isotopes of hydrogen, using the newly developed multi-component quantum theory of atoms in molecules (MC-QTAIM) analysis, employing ab initio non-Born-Oppenhiemer wavefunctions. Accordingly, the "atoms in molecules" analysis performed on various asymmetric exotic isotopomers of the hydrogen molecule, recently detected experimentally [Science, 2011, 331, 448], demonstrates that both the exotic isotopes are capable of forming atoms in molecules and retaining the identity of hydrogen atoms. Various derived properties of atomic basins containing the muonic helium cast no doubt that apart from its short life time, it is a heavier isotope of hydrogen while the properties of basins containing the positively charged muon are more remote from those of the orthodox hydrogen basins, capable of appreciable donation of electrons as well as large charge polarization. However, with some tolerance, they may also be categorized as hydrogen basins though with a smaller electronegativity. All in all, the present study also clearly demonstrates that the MC-QTAIM analysis is an efficient approach to decipher the chemical nature of species containing exotic constituents, which are difficult to elucidate by experimental and/or alternative theoretical schemes.

The role of indigenous wild, semidomestic, and exotic birds in the epizootiology of velogenic viscerotropic Newcastle disease in southern California, 1972-1973

USGS Publications Warehouse

Pearson, G.L.; McCann, M.K.

1975-01-01

During an epornitic of velogenic viscerotropic Newcastle disease (VVND) in southern California, free-flying wild birds, captive and free-ranging semidomestic birds, and exotic birds were collected from the quarantine area to determine their role in the epizootiology of the disease. The VVND virus was isolated from 0.04% of 9,446 free-flying wild birds, 0.76% of 4,367 semidomestic birds, and 1.01% of 3,780 exotic birds examined. Three house sparrows and 1 crow directly associated with infected poultry flocks were the only free-flying wild birds from which VVND virus was isolated. Among semidomestic species, ducks, quail, chukars, pheasants, peafowl, pigeons, and doves were found to be infected. Psittacines, pittas, and toucans accounted for 92% of the VVND virus isolations from exotic birds. In addition, domestic Newcastle disease virus (NDV) was isolated from 0.29% of the free-flying wild birds, from 1.65% of the semidomestic birds, and from 0.19% of the exotic birds collected. Hemagglutination-inhibition against domestic NDV was demonstrated in 0.24% of 3,796 wild bird serums, 8.28% of 2,004 semidomestic bird serums, and 3.90% of 231 exotic bird serums tested.Although few free-flying wild birds were infected with VVND virus in this epornitic, the isolation of domestic NDV strains from free-flying wild ducks and mourning doves suggests the potential for transportation of NDV over long distances by migratory birds.

Injuries, envenomations and stings from exotic pets.

PubMed

Warwick, Clifford; Steedman, Catrina

2012-07-01

A variety of exotic vertebrate and invertebrate species are kept as 'pets' including fishes, amphibians (for example, frogs and toads), reptiles (turtles, crocodiles, lizards and snakes), birds, mammals (for example, primates, civets, and lions), and invertebrates (for example spiders, scorpions, and centipedes), and ownership of some of these animals is rising. Data for 2009-2011 suggest that the number of homes with reptiles rose by approximately 12.5%. Recent surveys, including only some of these animals, indicated that they might be present in around 18.6% of homes (equal to approximately 42 million animals of which around 40 million are indoor or outdoor fish). Many exotic 'pets' are capable of causing injury or poisoning to their keepers and some contacts prove fatal. We examined NHS Health Episode Statistics for England using selected formal categories for hospital admissions and bed days for 2004-2010 using the following categories of injury, envenomation or sting; bitten or struck by crocodile or alligator; bitten or crushed by other reptiles: contact with venomous snakes and lizards; contact with scorpions. Between 2004 and 2010 these data conservatively show a total of 760 full consultation episodes, 709 admissions and 2,121 hospital bed days were associated with injuries probably from exotic pets. Injuries, envenomations and stings from exotic pets constitute a small but important component of emerging medical problems. Greater awareness of relevant injuries and medical sequelae from exotic pet keeping may help medics formulate their clinical assessment and advice to patients.

Composition of fungal soil communities varies with plant abundance and geographic origin

PubMed Central

Reininger, Vanessa; Martinez-Garcia, Laura B.; Sanderson, Laura; Antunes, Pedro M.

2015-01-01

Interactions of belowground fungal communities with exotic and native plant species may be important drivers of plant community structure in invaded grasslands. However, field surveys linking plant community structure with belowground fungal communities are missing. We investigated whether a selected number of abundant and relatively rare plants, either native or exotic, from an old-field site associate with different fungal communities. We also assessed whether these plants showed different symbiotic relationships with soil biota through their roots. We characterized the plant community and collected roots to investigate fungal communities using 454 pyrosequencing and assessed arbuscular mycorrhizal colonization and enemy-induced lesions. Differences in fungal communities were considered based on the assessment of α- and β diversity depending on plant ‘abundance’ and ‘origin’. Plant abundance and origin determined the fungal community. Fungal richness was higher for native abundant as opposed to relatively rare native plant species. However, this was not observed for exotics of contrasting abundance. Regardless of their origin, β diversity was higher for rare than for abundant species. Abundant exotics in the community, which happen to be grasses, were the least mycorrhizal whereas rare natives were most susceptible to enemy attack. Our results suggest that compared with exotics, the relative abundance of remnant native plant species in our old-field site is still linked to the structure of belowground fungal communities. In contrast, exotic species may act as a disturbing agent contributing towards the homogenization of soil fungal communities, potentially changing feedback interactions. PMID:26371291

Exotic decays of the 125 GeV Higgs boson at future e+e- colliders

NASA Astrophysics Data System (ADS)

Liu, Zhen; Wang, Lian-Tao; Zhang, Hao

2017-06-01

The discovery of unexpected properties of the Higgs boson would offer an intriguing opportunity to shed light on some of the most profound puzzles in particle physics. Beyond Standard Model (BSM) decays of the Higgs boson could reveal new physics in a direct manner. Future electron-positron lepton colliders operating as Higgs factories, including CEPC, FCC-ee and ILC, with the advantages of a clean collider environment and large statistics, could greatly enhance sensitivity in searching for these BSM decays. In this work, we perform a general study of Higgs exotic decays at future e+e- lepton colliders, focusing on the Higgs decays with hadronic final states and/or missing energy, which are very challenging for the High-Luminosity program of the Large Hadron Collider (HL-LHC). We show that with simple selection cuts, (10-3-10-5) limits on the Higgs exotic decay branching fractions can be achieved using the leptonic decaying spectator Z boson in the associated production mode e+e-→ ZH. We further discuss the interplay between detector performance and Higgs exotic decays, and other possibilities of exotic decays. Our work is a first step in a comprehensive study of Higgs exotic decays at future lepton colliders, which is a key area of Higgs physics that deserves further investigation. Supported by Fermi Research Alliance, LLC (DE-AC02-07CH11359) with the U.S. Department of Energy, DOE (DE-SC0013642), IHEP(Y6515580U1), and IHEP Innovation (Y4545171Y2)

Sensitivity of Lyme Borreliosis Spirochetes to Serum Complement of Regular Zoo Animals: Potential Reservoir Competence of Some Exotic Vertebrates.

PubMed

Ticha, Lucie; Golovchenko, Maryna; Oliver, James H; Grubhoffer, Libor; Rudenko, Nataliia

2016-01-01

Reaction of vertebrate serum complement with different Borrelia burgdorferi sensu lato species is used as a basis in determining reservoir hosts among domesticated and wild animals. Borrelia burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii were tested for their sensitivity to sera of exotic vertebrate species housed in five zoos located in the Czech Republic. We confirmed that different Borrelia species have different sensitivity to host serum. We found that tolerance to Borrelia infection possessed by hosts might differ among individuals of the same genera or species and is not affected by host age or sex. Of all zoo animals included in our study, carnivores demonstrated the highest apparent reservoir competency for Lyme borreliosis spirochetes. We showed that selected exotic ungulate species are tolerant to Borrelia infection. For the first time we showed the high tolerance of Siamese crocodile to Borrelia as compared to the other studied reptile species. While exotic vertebrates present a limited risk to the European human population as reservoirs for the causative agents of Lyme borreliosis, cases of incidental spillover infection could lead to successful replication of the pathogens in a new host, changing the status of selected exotic species and their role in pathogen emergence or maintenance. The question if being tolerant to pathogen means to be a competent reservoir host still needs an answer, simply because the majority of exotic animals might never be exposed to spirochetes in their natural environment.

Correlated factors in amphibian decline: Exotic species and habitat change in western Washington

USGS Publications Warehouse

Adams, Michael J.

1999-01-01

Amphibian declines may frequently be associated with multiple, correlated factors. In western North America, exotic species and hydrological changes are often correlated and are considered 2 of the greatest threats to freshwater systems. Bullfrog (Rana catesbeiana) introductions are frequently cited as a threat to lentic-breeding anurans native to western North America and are a suspected factor in the decline of red-legged frogs (Rana aurora) in California. Introduced fish and habitat change are cited less frequently but are equally viable hypotheses. I examined the relation among introduced species, habitat, and the distribution and abundance of red-legged frogs in western Washington. Red-legged frog occurrence in the Puget Lowlands was more closely associated with habitat structure and the presence of exotic fish than with the presence of bull-frogs. The spread of exotics is correlated with a shift toward greater permanence in wetland habitats regionally. Conservation of more ephemeral wetland habitats may have direct benefits for some native amphibians and may also reduce the threat of exotic fish and bullfrogs, both of which were associated with permanent wetlands. Research and conservation efforts for lowland anurans in the West should emphasize the complexities of multiple contributing factors to amphibian losses.

Long-term changes in abundance and diversity of macrophyte and waterfowl populations in an estuary with exotic macrophytes and improving water quality

USGS Publications Warehouse

Rybicki, N.B.; Landwehr, J.M.

2007-01-01

We assessed species-specific coverage (km2) of a submerged aquatic vegetation (SAV) community in the fresh and upper oligohaline Potomac Estuary from 1985 to 2001 using a method combining field observations of species-proportional coverage data with congruent remotely sensed coverage and density (percent canopy cover) data. Biomass (estimated by density-weighted coverage) of individual species was calculated. Under improving water quality conditions, exotic SAV species did not displace native SAV; rather, the percent of natives increased over time. While coverage-based diversity did fluctuate and increased, richness-based community turnover rates were not significantly different from zero. SAV diversity was negatively related to nitrogen concentration. Differences in functional traits, such as reproductive potential, between the dominant native and exotic species may explain some interannual patterns in SAV. Biomass of native, as well as exotic, SAV species varied with factors affecting water column light attenuation. We also show a positive response by a higher trophic level, waterfowl, to SAV communities dominated by exotic SAV from 1959 to 2001. ?? 2007, by the American Society of Limnology and Oceanography, Inc.

Ethnobotanical review of the Mapuche medicinal flora: use patterns on a regional scale.

PubMed

Molares, Soledad; Ladio, Ana

2009-03-18

This paper aimed to present a quantitative review of information on Mapuche ethnobotany published for Argentina and Chile in the period 1955-2007. Sixteen ethnobotanical articles were studied quantitatively by utilizing ethnobotanical indices, non-parametric and multivariate tests. A total of 505 medicinal species, 304 native (60%) and 196 exotic (39%) were registered. Ailments were treated with both native and exotic species, although native showed higher values of consensus (between studies) than exotic, and were more frequently used in all cases. The most common ailments were gastro-intestinal pains (26%). Most cures used herbs (56%). Native species were obtained mainly by gathering in forests and ecotones (40%), and exotics by gathering in anthropogenic environments (28%). Our results demonstrate the existence of a common, shared body of knowledge of the medicinal flora at a regional level, integrating ancestral knowledge with foreign knowledge accumulated over time. Finally, reflecting cultural erosion, modern articles cited significantly fewer native plants than older articles; a trend not found with exotic species. The information offered can be used as a guide for future work on promising species for health care, and as background information for the development of bio-cultural conservation strategies.

Revisiting the ants of Melanesia and the taxon cycle: historical and human-mediated invasions of a tropical archipelago.

PubMed

Economo, Evan P; Sarnat, Eli M

2012-07-01

Understanding the historical evolution of biotas and the dynamics of contemporary human-mediated species introductions are two central tasks of biology. One hypothesis may address both-the taxon cycle. Taxon cycles are phases of range expansion and contraction coupled to ecological and evolutionary niche shifts. These historical invasion processes resemble human-mediated invasions in pattern and possibly mechanism, but both the existence of historical cycles and the roles of recent introductions are in question. We return to the system that originally inspired the taxon cycle-Melanesian ants-and perform novel tests of the hypothesis. We analyze (i) the habitat distributions of Fiji's entire ant fauna (183 species), (ii) ecological shifts associated with the in situ radiation of Fijian Pheidole in a phylogenetic context, and (iii) the ecological structure of a massive exotic ant invasion of the archipelago. Our analyses indicate lineages shift toward primary habitats, higher elevation, rarity, and ecological specialization with increasing level of endemism, consistent with taxon cycle predictions. The marginal habitats that historically formed a dispersal conduit in the Pacific are now mostly replaced by human-modified habitats dominated by a colonization pulse of exotic species. We propose this may represent the first phase of an incipient global cycle of human-mediated colonization, ecological shifts, and diversification.

Microscopy of the interacting Harper-Hofstadter model in the few-body limit

NASA Astrophysics Data System (ADS)

Tai, M. Eric; Lukin, Alexander; Rispoli, Matthew; Schittko, Robert; Menke, Tim; Borgnia, Dan; Preiss, Philipp; Grusdt, Fabian; Kaufman, Adam; Greiner, Markus

2017-04-01

The interplay of magnetic fields and interacting particles can lead to exotic phases of matter exhibiting topological order and high degrees of spatial entanglement. While these phases were discovered in a solid-state setting, recent techniques have enabled the realization of gauge fields in systems of ultracold neutral atoms, offering a new experimental paradigm for studying these novel states of matter. This complementary platform holds promise for exploring exotic physics in fractional quantum Hall systems due to the microscopic manipulation and precision possible in cold atom systems. However, these experiments thus far have mostly explored the regime of weak interactions. Here, we show how strong interactions can modify the propagation of particles in a 2 × N , real-space ladder governed by the Harper-Hofstadter model. We observe inter-particle interactions affect the populating of chiral bands, giving rise to chiral dynamics whose multi-particle correlations indicate both bound and free-particle character. The novel form of interaction-induced chirality observed in these experiments demonstrates the essential ingredients for future investigations of highly entangled topological phases of many-body systems. We are supported by Grants from the National Science Foundation, Gordon and Betty Moore Foundation's EPiQS Initiative, an Air Force Office of Scientific Research MURI program, an Army Research Office MURI program, and the NSF GRFP (MNR).

Coevolution between invasive and native plants driven by chemical competition and soil biota.

PubMed

Lankau, Richard A

2012-07-10

Although reciprocal evolutionary responses between interacting species are a driving force behind the diversity of life, pairwise coevolution between plant competitors has received less attention than other species interactions and has been considered relatively less important in explaining ecological patterns. However, the success of species transported across biogeographic boundaries suggests a stronger role for evolutionary relationships in shaping plant interactions. Alliaria petiolata is a Eurasian species that has invaded North American forest understories, where it competes with native understory species in part by producing compounds that directly and indirectly slow the growth of competing species. Here I show that populations of A. petiolata from areas with a greater density of interspecific competitors invest more in a toxic allelochemical under common conditions. Furthermore, populations of a native competitor from areas with highly toxic invaders are more tolerant to competition from the invader, suggesting coevolutionary dynamics between the species. Field reciprocal transplants confirmed that native populations more tolerant to the invader had higher fitness when the invader was common, but these traits came at a cost when the invader was rare. Exotic species are often detrimentally dominant in their new range due to their evolutionary novelty; however, the development of new coevolutionary relationships may act to integrate exotic species into native communities.

The quest for novel modes of excitation in exotic nuclei

NASA Astrophysics Data System (ADS)

Paar, N.

2010-06-01

This paper provides an insight into several open problems in the quest for novel modes of excitation in nuclei with isospin asymmetry, deformation and finite-temperature characteristics in stellar environments. Major unsolved problems include the nature of pygmy dipole resonances, the quest for various multipole and spin-isospin excitations both in neutron-rich and proton drip-line nuclei mainly driven by loosely bound nucleons, excitations in unstable deformed nuclei and evolution of their properties with the shape phase transition. Exotic modes of excitation in nuclei at finite temperatures characteristic of supernova evolution present open problems with a possible impact in modeling astrophysically relevant weak interaction rates. All these issues challenge self-consistent many-body theory frameworks at the frontiers of on-going research, including nuclear energy density functionals, both phenomenological and constrained by the strong interaction physics of QCD, models based on low-momentum two-nucleon interaction Vlow-k and correlated realistic nucleon-nucleon interaction VUCOM, supplemented by three-body force, as well as two-nucleon and three-nucleon interactions derived from the chiral effective field theory. Joined theoretical and experimental efforts, including research with radioactive isotope beams, are needed to provide insight into dynamical properties of nuclei away from the valley of stability, involving the interplay of isospin asymmetry, deformation and finite temperature.

Direct reaction theories for exotic nuclei: An introduction via semi-classical methods

NASA Astrophysics Data System (ADS)

Bonaccorso, Angela

2018-07-01

The structure of exotic nuclei has only been studied from around 1985, because they are very short lived and because before that, it was not possible to produce and deliver them as beams on a target. They have large N / Z or Z / N ratios, are weakly bound and quite extended most of the time. Thus breakup, transfer and/or inelastic excitations of the surface are some of their most common reaction mechanisms. Direct reactions, for their simplicity, have played a fundamental role in the last thirty years in the process of understanding such "new" type of structures. On the other hand, direct reactions have been studied and understood for a much longer time, starting with the pioneering experiments in the early '50 on deuteron-induced reactions and the reaction models developed by S.T. Butler and collaborators. Both subjects are extremely vast and there is a large literature available of books, review articles and original papers. I will discuss here only a few selected examples of the many interesting problems that have been encountered and solved in all those years. I consider them breakthroughs in the field and as such I hope they can inspire young generations of researchers.

Super-light baryo-photons, weak gravity conjecture and exotic instantons in neutron-antineutron transitions

NASA Astrophysics Data System (ADS)

Addazi, Andrea

2018-05-01

In companion papers (A. Addazi, Nuovo Cim. C, 38(1): 21 (2015); A. Addazi, Z. Berezhiani, and Y. Kamyshkov, arXiv:1607.00348), we have discussed current bounds on a new super-light baryo-photon, associated with a U(1) B-L gauge, from current neutron-antineutron data, which are competitive with Eötvös-type experiments. Here, we discuss the implications of possible baryo-photon detection in string theory and quantum gravity. The discovery of a very light gauge boson should imply violation of the weak gravity conjecture, carrying deep consequences for our understanding of holography, quantum gravity and black holes. We also show how the detection of a baryo-photon would exclude the generation of all B–L violating operators from exotic stringy instantons. We will argue against the common statement in the literature that neutron-antineutron data may indirectly test at least the 300–1000 TeV scale. Searches for baryo-photons can provide indirect information on the Planck (or string) scale (quantum black holes, holography and non-perturbative stringy effects). This strongly motivates new neutron-antineutron experiments with adjustable magnetic fields dedicated to the detection of super-light baryo-photons.

9 CFR 352.8 - Time of inspection in the field and in an official exotic animal establishment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION EXOTIC ANIMALS AND HORSES...

Controlling exotic plants in your forest

Treesearch

James H. Miller

1999-01-01

The author discusses the impacts of exotic plants and suggests control and rehabilitation measures. Trees, shrubs, and vines addressed include silk tree or mimosa, Chinese and Japanese privet, kudzu, multiflora rose, Japanese honeysuckle, and Chinese wisteria.

Influence of Marangoni flows on the dynamics of isothermal A + B → C reaction fronts.

PubMed

Tiani, R; Rongy, L

2016-09-28

The nonlinear dynamics of A + B → C fronts is analyzed both numerically and theoretically in the presence of Marangoni flows, i.e., convective motions driven by surface tension gradients. We consider horizontal aqueous solutions where the three species A, B, and C can affect the surface tension of the solution, thereby driving Marangoni flows. The resulting dynamics is studied by numerically integrating the incompressible Navier-Stokes equations coupled to reaction-diffusion-convection (RDC) equations for the three chemical species. We show that the dynamics of the front cannot be predicted solely on the basis of the one-dimensional reaction-diffusion profiles as is the case for buoyancy-driven convection around such fronts. We relate this observation to the structure of Marangoni flows which lead to more complex and exotic dynamics. We find in particular the surprising possibility of a reversal of the front propagation direction in time for some sets of Marangoni numbers, quantifying the influence of each chemical species concentration on the solution surface tension. We explain this reversal analytically and propose a new classification of the convective effects on A + B → C reaction fronts as a function of the Marangoni numbers. The influence of the layer thickness on the RDC dynamics is also presented. Those results emphasize the importance of flow symmetry properties when studying convective front dynamics in a given geometry.

Kerman's Problem in the Continuum

NASA Astrophysics Data System (ADS)

Macchiavelli, A. O.; Casten, R. F.; Clark, R. M.; Campbell, C. M.; Crawford, H. L.; Cromaz, M.; Fallon, P.; Jones, M. D.; Salathe, M.

2017-09-01

In 1956 Kerman published a seminal paper on rotational perturbations in nuclei. Since then, Coriolis and rotational alignment effects have been extensively studied and are rather well understood. With the development of exotic beam facilities and advanced instrumentation it is becoming possible to access regions of deformation in the nuclear chart, near the neutron drip-line. Here, the effects of weak binding are expected to play an important role, affecting the dynamics of the nuclear motion. In this work we study Kerman's problem when the single-particle levels involved are resonant states. We will present results showing the behavior of the kinematic and dynamic moments of inertia as a function of the state widths. Connection to possible experiments will be discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contract No. DE-AC02-05CH11231 (LBNL).

JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei

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

Papenbrock, Thomas

2014-05-16

The grant “JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei ” (DOE DE-FG02-06ER41407) ran from 02/01/2006 thru 12/31/2013. JUSTIPEN is a venue for international collaboration between U.S.-based and Japanese scientists who share an interest in theory of rare isotopes. Since its inception JUSTIPEN has supported many visitors, fostered collaborations between physicists in the U.S. and Japan, and enabled them to deepen our understanding of exotic nuclei and their role in cosmos.

Anatomy and Disorders of the Oral Cavity of Miscellaneous Exotic Companion Mammals.

PubMed

Lennox, Angela M; Miwa, Yasutsugu

2016-09-01

Unusual mammalian species such as the hedgehog, sugar glider, and miniature pig are encountered with increasing frequency in exotic companion medicine. Disease of the oral cavity can occur in any species; although occasionally encountered in exotic mammalian species, it is rarely described in the literature. Anatomy and dentition vary significantly; diagnosis and treatment are often extrapolated from that known in other species. The best-documented disease of the oral cavity in this group of species is oral neoplasia in the hedgehog. Copyright © 2016 Elsevier Inc. All rights reserved.

Grassland invaders and their mycorrhizal symbionts: a study across climate and invasion gradients

PubMed Central

Bunn, Rebecca A; Lekberg, Ylva; Gallagher, Christopher; Rosendahl, Søren; Ramsey, Philip W

2014-01-01

Controlled experiments show that arbuscular mycorrhizal fungi (AMF) can increase competitiveness of exotic plants, potentially increasing invasion success. We surveyed AMF abundance and community composition in Centaurea stoebe and Potentilla recta invasions in the western USA to assess whether patterns were consistent with mycorrhizal-mediated invasions. We asked whether (1) AMF abundance and community composition differ between native and exotic forbs, (2) associations between native plants and AMF shift with invading exotic plants, and (3) AMF abundance and/or community composition differ in areas where exotic plants are highly invasive and in areas where they are not. We collected soil and roots from invaded and native forb communities along invasion gradients and in regions with different invasion densities. We used AMF root colonization as a measure of AMF abundance and characterized AMF communities in roots using 454-sequencing of the LSU-rDNA region. All plants were highly colonized (>60%), but exotic forbs tended to be more colonized than natives (P < 0.001). We identified 30 AMF operational taxonomic units (OTUs) across sites, and community composition was best predicted by abiotic factors (soil texture, pH). Two OTUs in the genera Glomus and Rhizophagus dominated in most communities, and their dominance increased with invasion density (r = 0.57, P = 0.010), while overall OTU richness decreased with invasion density (r = −0.61, P = 0.006). Samples along P. recta invasion gradients revealed small and reciprocal shifts in AMF communities with >45% fungal OTUs shared between neighboring native and P. recta plants. Overall, we observed significant, but modest, differences in AMF colonization and communities between co-occurring exotic and native forbs and among exotic forbs across regions that differ in invasion pressure. While experimental manipulations are required to assess functional consequences, the observed patterns are not consistent with those expected from strong mycorrhizal-mediated invasions. PMID:24683461

Nest Predation by Commensal Rodents in Urban Bushland Remnants.

PubMed

Smith, Helen M; Dickman, Chris R; Banks, Peter B

2016-01-01

Exotic predators are a major threat to native wildlife in many parts of the world. Developing and implementing effective strategies to mitigate their effects requires robust quantitative data so that management can be evidence-based, yet in many ecosystems this is missing. Birds in particular have been severely impacted by exotic mammalian predators, and a plethora of studies on islands record predation of bird eggs, fledglings and adults by exotic species such as rodents, stoats and cats. By comparison, few studies have examined nest predation around mainland urban centres which often act as dispersal hubs, especially for commensal species such as rodents. Here, we experimentally examine nest predation rates in habitat patches with varying black rat (Rattus rattus) densities in Sydney, Australia and test whether these exotic rats have the effects expected of exotic predators using effect size benchmarks. In the case where black rats have replaced native Rattus spp., we expected that black rats, being more arboreal than native Rattus spp., would be a significant source of predation on birds because they can readily access the arboreal niche where many birds nest. We tested this idea using above-ground artificial nests to represent those of typical small bird species such as the New Holland honeyeater (Phylidonyris novaehollandiae). We found that fewer eggs were depredated by rodents on sites where we removed black rats compared to unmanipulated sites, and that the effect size calculated from the total number of eggs surviving beyond the typical incubation period was similar to that expected for an exotic predator. Our results suggest that, although Australian birds have co-evolved with native Rattus species, in the case where black rats have replaced native Rattus species, exotic black rats appear to pose an additive source of predation on birds in remnant habitats, most likely due to their ability to climb more efficiently than their native counterparts. Management of these commensal rodents may be necessary to retain urban birdlife.

Soil resources influence vegetation and response to fire and fire-surrogate treatments in sagebrush-steppe ecosystems

USGS Publications Warehouse

Rau, Benjamin M.; Chambers, Jeanne C.; Pyke, David A.; Roundy, Bruce A.; Schupp, Eugene W.; Doescher, Paul; Caldwell, Todd G.

2014-01-01

Current paradigm suggests that spatial and temporal competition for resources limit an exotic invader, cheatgrass (Bromus tectorum L.), which once established, alters fire regimes and can result in annual grass dominance in sagebrush steppe. Prescribed fire and fire surrogate treatments (mowing, tebuthiuron, and imazapic) are used to reduce woody fuels and increase resistance to exotic annuals, but may alter resource availability and inadvertently favor invasive species. We used four study sites within the Sagebrush Steppe Treatment Evaluation Project (SageSTEP) to evaluate 1) how vegetation and soil resources were affected by treatment, and 2) how soil resources influenced native herbaceous perennial and exotic annual grass cover before and following treatment. Treatments increased resin exchangeable NH4+, NO3−, H2PO4−, and K+, with the largest increases caused by prescribed fire and prolonged by application of imazapic. Burning with imazapic application also increased the number of wet growing degree days. Tebuthiuron and imazapic reduced exotic annual grass cover, but imazapic also reduced herbaceous perennial cover when used with prescribed fire. Native perennial herbaceous species cover was higher where mean annual precipitation and soil water resources were relatively high. Exotic annual grass cover was higher where resin exchangeable H2PO4− was high and gaps between perennial plants were large. Prescribed fire, mowing, and tebuthiuron were successful at increasing perennial herbaceous cover, but the results were often ephemeral and inconsistent among sites. Locations with sandy soil, low mean annual precipitation, or low soil water holding capacity were more likely to experience increased exotic annual grass cover after treatment, and treatments that result in slow release of resources are needed on these sites. This is one of few studies that correlate abiotic variables to native and exotic species cover across a broad geographic setting, and that demonstrates how soil resources potentially influence the outcome of management treatments.

Nest Predation by Commensal Rodents in Urban Bushland Remnants

PubMed Central

2016-01-01

Exotic predators are a major threat to native wildlife in many parts of the world. Developing and implementing effective strategies to mitigate their effects requires robust quantitative data so that management can be evidence-based, yet in many ecosystems this is missing. Birds in particular have been severely impacted by exotic mammalian predators, and a plethora of studies on islands record predation of bird eggs, fledglings and adults by exotic species such as rodents, stoats and cats. By comparison, few studies have examined nest predation around mainland urban centres which often act as dispersal hubs, especially for commensal species such as rodents. Here, we experimentally examine nest predation rates in habitat patches with varying black rat (Rattus rattus) densities in Sydney, Australia and test whether these exotic rats have the effects expected of exotic predators using effect size benchmarks. In the case where black rats have replaced native Rattus spp., we expected that black rats, being more arboreal than native Rattus spp., would be a significant source of predation on birds because they can readily access the arboreal niche where many birds nest. We tested this idea using above-ground artificial nests to represent those of typical small bird species such as the New Holland honeyeater (Phylidonyris novaehollandiae). We found that fewer eggs were depredated by rodents on sites where we removed black rats compared to unmanipulated sites, and that the effect size calculated from the total number of eggs surviving beyond the typical incubation period was similar to that expected for an exotic predator. Our results suggest that, although Australian birds have co-evolved with native Rattus species, in the case where black rats have replaced native Rattus species, exotic black rats appear to pose an additive source of predation on birds in remnant habitats, most likely due to their ability to climb more efficiently than their native counterparts. Management of these commensal rodents may be necessary to retain urban birdlife. PMID:27295091

Disturbance by an endemic rodent in an arid shrubland is a habitat filter: effects on plant invasion and taxonomical, functional and phylogenetic community structure

PubMed Central

Escobedo, Víctor M.; Rios, Rodrigo S.; Salgado-Luarte, Cristian; Stotz, Gisela C.

2017-01-01

Abstract Background and Aims Disturbance often drives plant invasion and may modify community assembly. However, little is known about how these modifications of community patterns occur in terms of taxonomic, functional and phylogenetic structure. This study evaluated in an arid shrubland the influence of disturbance by an endemic rodent on community functional divergence and phylogenetic structure as well as on plant invasion. It was expected that disturbance would operate as a habitat filter favouring exotic species with short life cycles. Methods Sixteen plots were sampled along a disturbance gradient caused by the endemic fossorial rodent Spalacopus cyanus, measuring community parameters and estimating functional divergence for life history traits (functional dispersion index) and the relative contribution to functional divergence of exotic and native species. The phylogenetic signal (Pagel’s lambda) and phylogenetic community structure (mean phylogenetic distance and mean nearest taxon phylogenetic distance) were also estimated. The use of a continuous approach to the disturbance gradient allowed the identification of non-linear relationships between disturbance and community parameters. Key Results The relationship between disturbance and both species richness and abundance was positive for exotic species and negative for native species. Disturbance modified community composition, and exotic species were associated with more disturbed sites. Disturbance increased trait convergence, which resulted in phylogenetic clustering because traits showed a significant phylogenetic signal. The relative contribution of exotic species to functional divergence increased, while that of natives decreased, with disturbance. Exotic and native species were not phylogenetically distinct. Conclusions Disturbance by rodents in this arid shrubland constitutes a habitat filter over phylogeny-dependent life history traits, leading to phylogenetic clustering, and drives invasion by favouring species with short life cycles. Results can be explained by high phenotypic and phylogenetic resemblance between exotic and native species. The use of continuous gradients when studying the effects of disturbance on community assembly is advocated. PMID:28087661

Effect of the chameleon scalar field on brane cosmological evolution

NASA Astrophysics Data System (ADS)

Bisabr, Y.; Ahmadi, F.

2017-11-01

We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential function. The scalar field interacts with matter and there is an energy transfer between the two components. We find a late-time asymptotic solution which exhibits late-time accelerating expansion. We also show that the Universe recently crosses the phantom barrier without recourse to any exotic matter. We provide some thermodynamic arguments which constrain both the direction of energy transfer and dynamics of the extra dimension.

{alpha}+{sup 6,8}He resonant scattering and exotic structures in {sup 10,12}Be

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

Ito, Makoto; Itagaki, Naoyuki

2008-05-21

The {alpha}+{sup 6}He low-energy reactions and the structural changes of {sup 10}Be in the microscopic {alpha}+{alpha}+2N model are studied by the generalized two-center cluster model with the Kohn-Hulthen-Kato variation method. It is found that, in the inelastic scattering to the {alpha}+{sup 6}He(2{sub 1}{sup +}) channel, characteristic enhancements are expected as the results of the parity-dependent non-adiabatic dynamics. The similar method is applied to the resonant scattering of {alpha}+{sup 8}He, and the coupling with the compound configurations of {alpha}+{alpha}+4N are discussed.

9 CFR 82.13 - Denial and withdrawal of permits and special permits.

Code of Federal Regulations, 2012 CFR

2012-01-01

... PRODUCTS EXOTIC NEWCASTLE DISEASE (END) AND CHLAMYDI-OSIS Exotic Newcastle Disease (END) § 82.13 Denial and... way that threatens the public health, interest, or safety. The Administrator will send the person to...

9 CFR 82.13 - Denial and withdrawal of permits and special permits.

Code of Federal Regulations, 2011 CFR

2011-01-01

... PRODUCTS EXOTIC NEWCASTLE DIS- EASE (END) AND CHLAMYDIOSIS Exotic Newcastle Disease (END) § 82.13 Denial... way that threatens the public health, interest, or safety. The Administrator will send the person to...

9 CFR 82.13 - Denial and withdrawal of permits and special permits.

Code of Federal Regulations, 2013 CFR

2013-01-01

... PRODUCTS EXOTIC NEWCASTLE DISEASE (END) AND CHLAMYDI-OSIS Exotic Newcastle Disease (END) § 82.13 Denial and... way that threatens the public health, interest, or safety. The Administrator will send the person to...

Exotic quantum effects in the laboratory?

PubMed

Schützhold, Ralf

2008-08-28

This article provides a brief (non-exhaustive) review of some recent developments regarding the theoretical and possibly experimental study of 'exotic' quantum effects in the laboratory with special emphasis on cosmological particle creation, Hawking radiation and the Unruh effect.

Helminth communities of the exotic introduced turtle, Trachemys scripta elegans in southwestern Spain: Transmission from native turtles.

PubMed

Hidalgo-Vila, J; Díaz-Paniagua, C; Ribas, A; Florencio, M; Pérez-Santigosa, N; Casanova, J C

2009-06-01

We report the prevalence and diversity of helminth parasites found in native turtles Mauremys leprosa and Emys orbicularis from three localities in southwestern Spain and we describe the helminth communities of exotic turtles Trachemys scripta elegans coexisting in the wild with both native turtle species. Five nematodes species were identified, of which Serpinema microcephalus was the only species common between two localities, although infection parameters were different between them. This is the first report of cross transmission of S. microcephalus and Falcaustra donanaensis from native to exotic turtles and the first report of genus Physaloptera in turtles of the Palearctic Region. Continuous releasing of exotic pet turtles in wildlife ecosystems increases the risk of parasite introductions and, consequently, potential transmission to native species, and highlights the impending need for regulation of pet turtle trade in Europe.

Exotic looped trajectories of photons in three-slit interference

PubMed Central

Magaña-Loaiza, Omar S; De Leon, Israel; Mirhosseini, Mohammad; Fickler, Robert; Safari, Akbar; Mick, Uwe; McIntyre, Brian; Banzer, Peter; Rodenburg, Brandon; Leuchs, Gerd; Boyd, Robert W.

2016-01-01

The validity of the superposition principle and of Born's rule are well-accepted tenants of quantum mechanics. Surprisingly, it has been predicted that the intensity pattern formed in a three-slit experiment is seemingly in contradiction with the most conventional form of the superposition principle when exotic looped trajectories are taken into account. However, the probability of observing such paths is typically very small, thus rendering them extremely difficult to measure. Here we confirm the validity of Born's rule and present the first experimental observation of exotic trajectories as additional paths for the light by directly measuring their contribution to the formation of optical interference fringes. We accomplish this by enhancing the electromagnetic near-fields in the vicinity of the slits through the excitation of surface plasmons. This process increases the probability of occurrence of these exotic trajectories, demonstrating that they are related to the near-field component of the photon's wavefunction. PMID:28008907

Exotic looped trajectories of photons in three-slit interference.

PubMed

Magaña-Loaiza, Omar S; De Leon, Israel; Mirhosseini, Mohammad; Fickler, Robert; Safari, Akbar; Mick, Uwe; McIntyre, Brian; Banzer, Peter; Rodenburg, Brandon; Leuchs, Gerd; Boyd, Robert W

2016-12-23

The validity of the superposition principle and of Born's rule are well-accepted tenants of quantum mechanics. Surprisingly, it has been predicted that the intensity pattern formed in a three-slit experiment is seemingly in contradiction with the most conventional form of the superposition principle when exotic looped trajectories are taken into account. However, the probability of observing such paths is typically very small, thus rendering them extremely difficult to measure. Here we confirm the validity of Born's rule and present the first experimental observation of exotic trajectories as additional paths for the light by directly measuring their contribution to the formation of optical interference fringes. We accomplish this by enhancing the electromagnetic near-fields in the vicinity of the slits through the excitation of surface plasmons. This process increases the probability of occurrence of these exotic trajectories, demonstrating that they are related to the near-field component of the photon's wavefunction.

Exotic species as models to understand biocultural adaptation: Challenges to mainstream views of human-nature relations

PubMed Central

Gama, Aline Dourado Sena; de Paula, Marcelo; da Silva, Rafael Ricardo Vasconcelos; Ferreira, Washington Soares

2018-01-01

A central argument in the research on traditional knowledge, which persists in the scientific literature, is that the entrance of exotic plants in local medical systems is directly associated with acculturation. However, this logic has put an end for a long period to efforts to understand why such species have so successfully entered socio-ecological systems or even their real role in such systems. This study provides evidence that (1) in some socio-environmental contexts, exotic medicinal species usually confer greater adaptive advantages to local populations, and (2) despite their general importance, exotic species only excel in medical systems when cost-benefit ratio is favorable to them. Thus, in order to avoid the loss of knowledge about native plants and to ensure biocultural conservation, it is necessary to create strategies to amplify the advantages of these species. PMID:29708981

Structural risk and limits on agency among exotic dancers: HIV risk practices in the exotic dance club.

PubMed

Footer, Katherine H A; Lim, Sahnah; Brantley, Meredith R; Sherman, Susan G

2018-03-01

This paper provides longitudinal examination of women's health and sexual risk trajectories in US exotic dance clubs, which represent an important commercial setting for the economic mainstreaming of sexual services and an important target for public health programmes. Between July 2014 and May 2015, two semi-structured interviews (at baseline and at three months) were conducted with 24 female exotic dancers who had recently started working in in Baltimore City, USA. Results from a constant comparative analysis point to the interrelationship between the structures of the club setting, including the social context, and women's agentic practices concerning their sexual health. Study findings highlight the centrality of the interrelationship between individual- and structural-level experiences in influencing dancers' risk behavior. Findings point to the need for interventions to empower women both individually and collectively so as to provide the foundation for longer-term structural change.

ExNOTic: Should We Be Keeping Exotic Pets?

PubMed Central

Grant, Rachel A.; Montrose, V. Tamara; Wills, Alison P.

2017-01-01

There has been a recent trend towards keeping non-traditional companion animals, also known as exotic pets. These pets include parrots, reptiles, amphibians and rabbits, as well as small species of rodent such as degus and guinea pigs. Many of these exotic pet species are not domesticated, and often have special requirements in captivity, which many owners do not have the facilities or knowledge to provide. Keeping animals in settings to which they are poorly adapted is a threat to their welfare. Additionally, owner satisfaction with the animal may be poor due to a misalignment of expectations, which further impacts on welfare, as it may lead to repeated rehoming or neglect. We investigate a range of commonly kept exotic species in terms of their suitability as companion animals from the point of view of animal welfare and owner satisfaction, and make recommendations on the suitability of various species as pets. PMID:28629177

Exotic QTL improve grain quality in the tri-parental wheat population SW84

PubMed Central

Nedelkou, Ioanna-Pavlina; Maurer, Andreas; Schubert, Anne; Léon, Jens

2017-01-01

Developing the tri-parental exotic wheat population SW84 Genetic diversity of cultivated wheat was markedly reduced, first, during domestication and, second, since the onset of modern elite breeding. There is an increasing demand for utilizing genetic resources to increase genetic diversity and, simultaneously, to improve agronomic performance of cultivated wheat. To locate favorable effects of exotic wheat alleles, we developed the tri-parental wheat population SW84. The population was derived from crossing the hexaploid spring wheat cultivars Triso and Devon with one synthetic exotic donor accession, Syn084L, followed by two rounds of backcrossing and three rounds of selfing. SW84 consists of 359 BC2F4 lines, split into two families, D84 (Devon*Syn084L) and T84 (Triso*Syn084L). Studying the genetic control of grain quality in SW84 As a case study, grain quality of SW84 was studied in replicated field trials. Transgressive segregation was observed for all studied grain quality traits by evaluating SW84 for two years at two locations under low and high nitrogen supply. Subsequently, a genome-wide association study (GWAS) was carried out based on genomic data derived from a 90k Infinium iSELECT single nucleotide polymorphism (SNP) array. In total, GWAS yielded 37 marker-trait associations, summarized to 16 quantitative trait loci (QTL). These SNPs indicate genetic regulators of grain protein content, grain hardness, sedimentation value and sedimentation ratio. The majority of exotic QTL alleles (75%) exerted favorable effects, increasing grain protein content and sedimentation value in ten and two cases, respectively. For instance, two exotic QTL alleles were associated with a substantial increase of grain protein content and sedimentation value by 1.09% and 7.31 ml, respectively. This finding confirms the potential of exotic germplasm to improve grain quality in cultivated wheat. So far, the molecular nature of most of the detected QTL is unknown. However, two QTL correspond to known genes controlling grain quality: The major QTL on chromosome 6B, increasing grain protein content by 0.70%, on average, co-localizes with the NAM-B1 gene, known to control grain protein content as well as iron and zinc content. Likewise, the major QTL on chromosome 5D, reducing grain hardness by 8.98%, on average, co-localizes with the gene for puroindoline b (Pinb-D1) at the Ha locus. In total, 13 QTL were detected across families, whereas one and three QTL were exclusively detected in families D84 and T84, respectively. Likewise, ten QTL were detected across nitrogen treatments, whereas one and five QTL were exclusively detected under low and high N treatments, respectively. Our data indicate that most effects in SW84 act across families and N levels. Merging of data from two families or two N treatments may, thus, be considered in association studies to increase sample size and, as a result, QTL detection power. Utilizing favorable exotic QTL alleles in wheat breeding Our study serves as a model how favorable exotic QTL alleles can be located in exotic germplasm of wheat. In future, the localized favorable exotic QTL alleles will be utilized in wheat breeding programs to simultaneously improve grain quality and selectively expand genetic diversity of the elite wheat gene pool. PMID:28686676

Traditional Mapuche ecological knowledge in Patagonia, Argentina: fishes and other living beings inhabiting continental waters, as a reflection of processes of change.

PubMed

Aigo, Juana; Ladio, Ana

2016-12-07

Understanding how people interpret environmental change and develop practices in response to such change is essential to comprehend human resource use. In the cosmology of the American indigenous peoples, as among the Mapuche people, freshwater systems are considered a living entity, where animals have an enormous role to play in the universe of meaning. However, human adaptive responses to freshwater system dynamics are scarcely examined. In this work a survey is carried out in three Mapuche communities of Argentine Patagonia to assess their traditional knowledge of the fishes and other non-human living beings that inhabit lakes and rivers. Both material and symbolic aspects are included, as are the differences in knowledge and use of the fishes between past and present times. Our methods were based on a quali-quantitative fieldwork approach. In-depth interviews were carried out with 36 individuals from three rural Mapuche populations in Neuquén province (Patagonia, Argentina). Free listing was used for inquiring about fish knowledge and use. Fishes were identified scientifically and ethnotaxonomically. In-depth analysis of the discourses was conducted, documenting the recognition, perception, and cultural significance of fluvial environments and their inhabitants. Quantitative survey results were analyzed with categorical statistical methods. The body of knowledge of the communities studied reflects the socio-environmental changes experienced by Patagonian freshwater bodies. According to local perception, non-human beings live in these water bodies, guarding the environment, and they should not be disturbed. At present, five different fish species are identified, three of which are exotic, having been introduced at the beginning of the 20th century by the white man. These exotic trout (Oncorhynchus mykiss and Salvelinus fontinalis) are considered ill omens, indicators of the white man's presence, and therefore their appearance presages negative events for the families. In addition, we found that Mapuche people differentiate fish species mainly by morphological, organoleptic and ecological attributes. Current consumption of fish by Mapuche communities is sporadic, in accordance with bibliography and ancient tales. Several fishing tools are used, including modern elements. Our data enable us to characterise dynamic traditional knowledge in these communities, which is flexible in nature and adaptable to new situations, demonstrated by the incorporation not only of new species but also new fishing tools. It also seems that new significances become absorbed in synchrony with the advance or arrival of exotic and invasive species. For the Mapuche, the presence of the white man heralded by exotic trouts speaks of how a recent event, such as the introduction of the salmonids, is already incorporated into Mapuche symbolism. Mapuche traditional knowledge and cosmovision on the use of fish and waters, a vision which promotes respect and the avoidance of actions that could disturb the beings (animals and sacred or mythological characters) that inhabit and take care of them should be fostered as part of management plans of regional natural resources. This paper contributes to the broader literature on freshwater resource management by providing empirical evidence of the critical role of local perceptions in promoting the sustainable management of natural resources.

Establishment Success of Coexisting Native and Exotic Trees Under an Experimental Gradient of Irradiance and Soil Moisture

NASA Astrophysics Data System (ADS)

González-Muñoz, Noelia; Castro-Díez, Pilar; Fierro-Brunnenmeister, Natalia

2011-10-01

The exotic trees Ailanthus altissima, Robinia pseudoacacia, Acer negundo and Elaeagnus angustifolia coexist with the native trees Fraxinus angustifolia and Ulmus minor in river banks of central Spain. Similarly, the exotic trees Acacia dealbata and Eucalyptus globulus co-occur with the natives Quercus pyrenaica and Pinus pinaster in Northwest Spain. We aimed to identify the environmental conditions that favour or hamper the establishment success of these species. In spring 2008, seeds of the studied species were sown under an experimental gradient of light (100, 65, 35, 7% of full sunlight) combined with three levels of soil moisture (mean soil water potential = -0.97, -1.52 and -1.77 MPa.). During the first growing season we monitored seed emergence and seedling survival. We found that the effect of light on the establishment success was stronger than the effect of soil moisture. Both exotic and native species of central Spain showed a good performance under high light, A. negundo being the most shade tolerant . Water shortage diminished E. angustifolia and A. altissima success. Among NW Spain species, A. dealbata and P. pinaster were found to be potential competitors for colonizing high-irradiance scenarios, while Q. pyrenaica and E. globulus were more successful under moderate shade. High soil moisture favoured E. globulus but not A. dealbata establishment. These results contribute to understand some of the factors controlling for spatial segregation between coexisting native and exotic tree species, and can help to take decisions orientated to the control and management of these exotic species.

Thermotolerance capacities of native and exotic coastal plants will lead to changes in species composition under increased heat waves

PubMed Central

Robinson, Sharon A.; Lia, Jodie

2017-01-01

Abstract With an increase in the frequency and intensity of extreme heat events, plants are likely to reach their thermal limits and show slower growth or increased mortality. We investigated differences amongst coastal native and invasive shrubs and grasses to investigate if particular species might be more at risk in the future. Using an ecologically relevant experimental set of heat waves over a month, we assessed changes in biomass and photosynthetic efficiency in a laboratory setting using 25 coastal Australian species divided into native and exotic shrubs, and native and exotic grasses. We also compared three C3 and three C4 grasses within the native and exotic groups. Overall, native shrubs suffered higher mortality, lower growth and increased photosynthetic stress. There was some evidence that C3 grasses, had lower growth with heat waves, compared to C4 species although, in general, grasses showed evidence of photosynthetic acclimation over the month. Increases in leaf abscission suggest that part of the acclimation process was to develop new, thermally tolerant leaves. Our results indicate that in the future we would expect an increase in exotic shrubs and grasses occupying spaces in coastal plant communities that arise from native mortality following extreme heat events. Management of these coastal communities will need to focus strongly on maintaining a diverse native shrub composition that can resist climate-based disturbances (such as wildfire), as well as controlling the extent and biomass of exotic species, if coastal communities are to remain healthy and diverse in a changing climate. PMID:28491321

Establishment success of coexisting native and exotic trees under an experimental gradient of irradiance and soil moisture.

PubMed

González-Muñoz, Noelia; Castro-Díez, Pilar; Fierro-Brunnenmeister, Natalia

2011-10-01

The exotic trees Ailanthus altissima, Robinia pseudoacacia, Acer negundo and Elaeagnus angustifolia coexist with the native trees Fraxinus angustifolia and Ulmus minor in river banks of central Spain. Similarly, the exotic trees Acacia dealbata and Eucalyptus globulus co-occur with the natives Quercus pyrenaica and Pinus pinaster in Northwest Spain. We aimed to identify the environmental conditions that favour or hamper the establishment success of these species. In spring 2008, seeds of the studied species were sown under an experimental gradient of light (100, 65, 35, 7% of full sunlight) combined with three levels of soil moisture (mean soil water potential = -0.97, -1.52 and -1.77 MPa.). During the first growing season we monitored seed emergence and seedling survival. We found that the effect of light on the establishment success was stronger than the effect of soil moisture. Both exotic and native species of central Spain showed a good performance under high light, A. negundo being the most shade tolerant. Water shortage diminished E. angustifolia and A. altissima success. Among NW Spain species, A. dealbata and P. pinaster were found to be potential competitors for colonizing high-irradiance scenarios, while Q. pyrenaica and E. globulus were more successful under moderate shade. High soil moisture favoured E. globulus but not A. dealbata establishment. These results contribute to understand some of the factors controlling for spatial segregation between coexisting native and exotic tree species, and can help to take decisions orientated to the control and management of these exotic species.

Marine exotic isopods from the Iberian Peninsula and nearby waters.

PubMed

Martínez-Laiz, Gemma; Ros, Macarena; Guerra-García, José M

2018-01-01

Effective management of marine bioinvasions starts with prevention, communication among the scientific community and comprehensive updated data on the distribution ranges of exotic species. Despite being a hotspot for introduction due to numerous shipping routes converging at the Strait of Gibraltar, knowledge of marine exotics in the Iberian Peninsula is scarce, especially of abundant but small-sized and taxonomically challenging taxa such as the Order Isopoda. To fill this gap, we conducted several sampling surveys in 44 marinas and provide the first comprehensive study of marine exotic isopods from the Iberian Peninsula, the southern side of the Strait of Gibraltar (northern Africa) and the Balearic Islands. Exotic species included Ianiropsis serricaudis (first record for the Iberian Peninsula and Lusitanian marine province), Paracerceis sculpta (first record for the Alboran Sea ecoregion), Paradella dianae , Paranthura japonica (earliest record for the Iberian Peninsula) and Sphaeroma walkeri . Photographs with morphological details for identification for non-taxonomic experts are provided, their worldwide distribution is updated and patterns of invasion are discussed. We report an expansion in the distribution range of all species, especially at the Strait of Gibraltar and nearby areas. Ianiropsis serricaudis and Paranthura japonica are polyvectic, with shellfish trade and recreational boating being most probable vectors for their introduction and secondary spread. The subsequent finding of the studied species in additional marinas over the years points at recreational boating as a vector and indicates a future spread. We call for attention to reduce lags in the detection and reporting of small-size exotics, which usually remain overlooked or underestimated until the invasion process is at an advanced stage.

Marine exotic isopods from the Iberian Peninsula and nearby waters

PubMed Central

Ros, Macarena; Guerra-García, José M.

2018-01-01

Effective management of marine bioinvasions starts with prevention, communication among the scientific community and comprehensive updated data on the distribution ranges of exotic species. Despite being a hotspot for introduction due to numerous shipping routes converging at the Strait of Gibraltar, knowledge of marine exotics in the Iberian Peninsula is scarce, especially of abundant but small-sized and taxonomically challenging taxa such as the Order Isopoda. To fill this gap, we conducted several sampling surveys in 44 marinas and provide the first comprehensive study of marine exotic isopods from the Iberian Peninsula, the southern side of the Strait of Gibraltar (northern Africa) and the Balearic Islands. Exotic species included Ianiropsis serricaudis (first record for the Iberian Peninsula and Lusitanian marine province), Paracerceis sculpta (first record for the Alboran Sea ecoregion), Paradella dianae, Paranthura japonica (earliest record for the Iberian Peninsula) and Sphaeroma walkeri. Photographs with morphological details for identification for non-taxonomic experts are provided, their worldwide distribution is updated and patterns of invasion are discussed. We report an expansion in the distribution range of all species, especially at the Strait of Gibraltar and nearby areas. Ianiropsis serricaudis and Paranthura japonica are polyvectic, with shellfish trade and recreational boating being most probable vectors for their introduction and secondary spread. The subsequent finding of the studied species in additional marinas over the years points at recreational boating as a vector and indicates a future spread. We call for attention to reduce lags in the detection and reporting of small-size exotics, which usually remain overlooked or underestimated until the invasion process is at an advanced stage. PMID:29507825

Gravitational birefringence and an exotic formula for redshifts

NASA Astrophysics Data System (ADS)

Duval, Christian; Pasquet, Johanna; Schücker, Thomas; Tilquin, André

2018-06-01

We compute the birefringence of light in curved Robertson-Walker spacetimes and propose an exotic formula for redshift based on the internal structure of the spinning photon. We then use the Hubble diagram of supernovae to test this formula.

Bio-Invasions: The Spread of Exotic Species.

ERIC Educational Resources Information Center

Bright, Chris

1995-01-01

Human mobility has radically increased the rate at which large numbers of living things are moving from one ecosystem to another. Discusses how ecosystems change when "exotic" species invade natural communities and notes efforts to control adverse effects. (LZ)

Accelerated development in Johnsongrass seedlings (Sorghum halepense) suppresses the growth of native grasses through size-asymmetric competition

PubMed Central

Meckel, Heather; Reichmann, Lara G.; Polley, H. Wayne; Fay, Philip A.

2017-01-01

Invasive plant species often dominate native species in competition, augmenting other potential advantages such as release from natural enemies. Resource pre-emption may be a particularly important mechanism for establishing dominance over competitors of the same functional type. We hypothesized that competitive success of an exotic grass against native grasses is mediated by establishing an early size advantage. We tested this prediction among four perennial C4 warm-season grasses: the exotic weed Johnsongrass (Sorghum halepense), big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparius) and switchgrass (Panicum virgatum). We predicted that a) the competitive effect of Johnsongrass on target species would be proportional to their initial biomass difference, b) competitive effect and response would be negatively correlated and c) soil fertility would have little effect on competitive relationships. In a greenhouse, plants of the four species were grown from seed either alone or with one Johnsongrass neighbor at two fertilizer levels and periodically harvested. The first two hypotheses were supported: The seedling biomass of single plants at first harvest (50 days after seeding) ranked the same way as the competitive effect of Johnsongrass on target species: Johnsongrass < big bluestem < little bluestem/switchgrass, while Johnsongrass responded more strongly to competition from Johnsongrass than from native species. At final harvest, native plants growing with Johnsongrass attained between 2–5% of their single-plant non-root biomass, while Johnsongrass growing with native species attained 89% of single-plant non-root biomass. Fertilization enhanced Johnsongrass’ competitive effects on native species, but added little to the already severe competitive suppression. Accelerated early growth of Johnsongrass seedlings relative to native seedlings appeared to enable subsequent resource pre-emption. Size-asymmetric competition and resource-pre-emption may be a critical mechanism by which exotic invasive species displace functionally similar native species and alter the functional dynamics of native communities. PMID:28467488

Non-additive benefit or cost? Disentangling the indirect effects that occur when plants bearing extrafloral nectaries and honeydew-producing insects share exotic ant mutualists.

PubMed

Savage, Amy M; Rudgers, Jennifer A

2013-06-01

In complex communities, organisms often form mutualisms with multiple different partners simultaneously. Non-additive effects may emerge among species linked by these positive interactions. Ants commonly participate in mutualisms with both honeydew-producing insects (HPI) and their extrafloral nectary (EFN)-bearing host plants. Consequently, HPI and EFN-bearing plants may experience non-additive benefits or costs when these groups co-occur. The outcomes of these interactions are likely to be influenced by variation in preferences among ants for honeydew vs. nectar. In this study, a test was made for non-additive effects on HPI and EFN-bearing plants resulting from sharing exotic ant guards. Preferences of the dominant exotic ant species for nectar vs. honeydew resources were also examined. Ant access, HPI and nectar availability were manipulated on the EFN-bearing shrub, Morinda citrifolia, and ant and HPI abundances, herbivory and plant growth were assessed. Ant-tending behaviours toward HPI across an experimental gradient of nectar availability were also tracked in order to investigate mechanisms underlying ant responses. The dominant ant species, Anoplolepis gracilipes, differed from less invasive ants in response to multiple mutualists, with reductions in plot-wide abundances when nectar was reduced, but no response to HPI reduction. Conversely, at sites where A. gracilipes was absent or rare, abundances of less invasive ants increased when nectar was reduced, but declined when HPI were reduced. Non-additive benefits were found at sites dominated by A. gracilipes, but only for M. citrifolia plants. Responses of HPI at these sites supported predictions of the non-additive cost model. Interestingly, the opposite non-additive patterns emerged at sites dominated by other ants. It was demonstrated that strong non-additive benefits and costs can both occur when a plant and herbivore share mutualist partners. These findings suggest that broadening the community context of mutualism studies can reveal important non-additive effects and increase understanding of the dynamics of species interactions.

Regime Shift by an Exotic Nitrogen-Fixing Shrub Mediates Plant Facilitation in Primary Succession

PubMed Central

Stinca, Adriano; Chirico, Giovanni Battista; Incerti, Guido; Bonanomi, Giuliano

2015-01-01

Ecosystem invasion by non-native, nitrogen-fixing species is a global phenomenon with serious ecological consequences. However, in the Mediterranean basin few studies addressed the impact of invasion by nitrogen-fixing shrubs on soil quality and hydrological properties at local scale, and the possible effects on succession dynamics and ecosystem invasibility by further species. In this multidisciplinary study we investigated the impact of Genista aetnensis (Biv.) DC., an exotic nitrogen-fixing shrub, on the Vesuvius Grand Cone (Southern Italy). Specifically, we tested the hypotheses that the invasion of G. aetnensis has a significant impact on soil quality, soil hydrological regime, local microclimate and plant community structure, and that its impact increases during the plant ontogenetic cycle. We showed that G. aetnensis, in a relatively short time-span (i.e. ~ 40 years), has been able to build-up an island of fertility under its canopy, by accumulating considerable stocks of C, N, and P in the soil, and by also improving the soil hydrological properties. Moreover, G. aetnensis mitigates the daily range of soil temperature, reducing the exposure of coexisting plants to extremely high temperatures and water loss by soil evaporation, particularly during the growing season. Such amelioration of soil quality, coupled with the mitigation of below-canopy microclimatic conditions, has enhanced plant colonization of the barren Grand Cone slopes, by both herbaceous and woody species. These results suggest that the invasion of G. aetnensis could eventually drive to the spread of other, more resource-demanding exotic species, promoting alternative successional trajectories that may dramatically affect the local landscape. Our study is the first record of the invasion of G. aetnensis, an additional example of the regime shifts driven by N-fixing shrubs in Mediterranean region. Further studies are needed to identity specific management practices that can limit the spread and impacts of this species. PMID:25835015

Belowground eco-restoration of a suburban waste-storage landscape: Earthworm dynamics in grassland and in a succession of woody vegetation covers☆

PubMed Central

Morales, Pamela K.; Yunusa, Isa A.M.; Lugg, Glenys; Li, Zheng; Gribben, Paul; Eamus, Derek

2013-01-01

Restoration of belowground ecology is seldom a priority in designing revegetation strategies for disturbed landscapes. We determined earthworm abundance and diversity in a 16-year old grass sward (grassland), a 6-year old (Plantation-04) and a 4-year old (Plantation-06) plantation, both of mixed woody species, on a reclaimed waste disposal site, and in nearby remnant woodland, in suburban Sydney, Australia. While no catches were made in autumn, more earthworms were found in spring (21 ± 8.6 m–2) than in winter (10.2 ± 5.9 m–2) or summer (14.4 ± 5.5 m–2). Earthworm abundance in spring was in the order grassland ≈ Plantation-04 (35.2 m–2) > woodland (12.8 m–2) > Plantation-06 (0.8 m–2). None of the revegetated covers had restored earthworm diversity to levels found in the woodland. Exotic species, mostly Microscolex dubius, dominated in the four vegetation covers at any time; the only two native species (Heteroporodrilus sp. and Megascoleceides sp.) found were in the woodland. We also assessed how quality of the evolving soils from the three revegetated covers, compared with that from the woodland, impacted viability of common exotic earthworm species. Both weight gain and cocoon production by the exotic earthworms were higher in the soil from Plantation-04 than in soils from the other vegetation covers, including the woodland; the two variables were positively correlated with the pH and mineral nutrient content (as indicated by electrical conductivity that was in turn correlated with clay content) of the soil. Age of vegetation rather than its composition explained differences in the level of earthworm recovery observed. PMID:25550677

Distribution and abundance of forest birds in low-altitude habitat on Hawai'i Island: Evidence for range expansion of native species

USGS Publications Warehouse

Spiegel, C.S.; Hart, P.J.; Woodwort, B.L.; Tweed, E.J.; Leburn, J.J.

2006-01-01

The Hawaiian honeycreepers are thought to be limited primarily to middle- and high-altitude wet forests due to anthropogenic factors at lower altitudes, especially introduced mosquitotransmitted avian malaria. However, recent research has demonstrated that at least one native species, the Hawai'i 'Amakihi (Hemignathus virens virens), is common in areas of active malaria transmission. We examined the current distribution and abundance of native and exotic forest birds within approximately 640 km2 of low-altitude (0-326 m) habitat on south-eastern Hawai'i Island, using roadside variable circular plot (VCP) at 174 stations along eight survey transects. We also re-surveyed 90 stations near sea level that were last surveyed in 1994-1995. Overall, introduced species were more abundant than natives; 11 exotic species made up 87% of the total individuals detected. The most common exotic passerines were Japanese White-eye (Zosterops japonicus), House Finch (Carpodacus mexicanus) and Northern Cardinal (Cardinalis cardinalis). Two native species, Hawai'i 'Amakihi and 'Apapane (Himatione sanguina), comprised 13% of the bird community at low altitudes. Hawai'i 'Amakihi were the most common and widespread native species, being found at 47% of stations at a density of 4.98 birds/ha (95% CI 3.52-7.03). Amakihi were significantly associated with 'ohi'a (Metrosideros polymorpha)-dominated forest. 'Apapane were more locally distributed, being found at only 10% of stations. Re-surveys of 1994-1995 transects demonstrated a significant increase in 'Amakihi abundance over the past decade. This work demonstrates a widespread recovery of Hawai'i 'Amakihi at low altitude in southeastern Hawai'i. The changing composition of the forest bird community at low-altitudes in Hawai'i has important implications for the dynamics of avian malaria in low-altitude Hawai'i, and for conservation of Hawai'i's lowland forests. ?? 2006 BirdLife International.

Accelerated development in Johnsongrass seedlings (Sorghum halepense) suppresses the growth of native grasses through size-asymmetric competition.

PubMed

Schwinning, Susanne; Meckel, Heather; Reichmann, Lara G; Polley, H Wayne; Fay, Philip A

2017-01-01

Invasive plant species often dominate native species in competition, augmenting other potential advantages such as release from natural enemies. Resource pre-emption may be a particularly important mechanism for establishing dominance over competitors of the same functional type. We hypothesized that competitive success of an exotic grass against native grasses is mediated by establishing an early size advantage. We tested this prediction among four perennial C4 warm-season grasses: the exotic weed Johnsongrass (Sorghum halepense), big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparius) and switchgrass (Panicum virgatum). We predicted that a) the competitive effect of Johnsongrass on target species would be proportional to their initial biomass difference, b) competitive effect and response would be negatively correlated and c) soil fertility would have little effect on competitive relationships. In a greenhouse, plants of the four species were grown from seed either alone or with one Johnsongrass neighbor at two fertilizer levels and periodically harvested. The first two hypotheses were supported: The seedling biomass of single plants at first harvest (50 days after seeding) ranked the same way as the competitive effect of Johnsongrass on target species: Johnsongrass < big bluestem < little bluestem/switchgrass, while Johnsongrass responded more strongly to competition from Johnsongrass than from native species. At final harvest, native plants growing with Johnsongrass attained between 2-5% of their single-plant non-root biomass, while Johnsongrass growing with native species attained 89% of single-plant non-root biomass. Fertilization enhanced Johnsongrass' competitive effects on native species, but added little to the already severe competitive suppression. Accelerated early growth of Johnsongrass seedlings relative to native seedlings appeared to enable subsequent resource pre-emption. Size-asymmetric competition and resource-pre-emption may be a critical mechanism by which exotic invasive species displace functionally similar native species and alter the functional dynamics of native communities.

Dynamical Formation and Merger of Binary Black Holes

NASA Astrophysics Data System (ADS)

Stone, Nicholas

2017-01-01

The advent of gravitational wave (GW) astronomy began with Advanced LIGO's 2015 discovery of GWs from coalescing black hole (BH) binaries. GW astronomy holds great promise for testing general relativity, but also for investigating open astrophysical questions not amenable to traditional electromagnetic observations. One such question concerns the origin of stellar mass BH binaries in the universe: do these form primarily from evolution of isolated binaries of massive stars, or do they form through more exotic dynamical channels? The best studied dynamical formation channel involves multibody interactions of BHs and stars in dense globular cluster environments, but many other dynamical scenarios have recently been proposed, ranging from the Kozai effect in hierarchical triple systems to BH binary formation in the outskirts of Toomre-unstable accretion disks surrounding supermassive black holes. The BH binaries formed through these processes will have different distributions of observable parameters (e.g. mass ratios, spins) than BH binaries formed through the evolution of isolated binary stars. In my talk I will overview these and other dynamical formation scenarios, and summarize the key observational tests that will enable Advanced LIGO or other future detectors to determine what formation pathway creates the majority of binary BHs in the universe. NCS thanks NASA, which has funded his work through Einstein postdoctoral grant PF5-160145.

Role of Native and Exotic Earthworms in Plant Biopolymer Dynamics in Forest Soil

NASA Astrophysics Data System (ADS)

Filley, Timothy

2010-05-01

Many forests within northern North America are experiencing the introduction of earthworms for the first time, presumably since before the last major glaciation. Forest dynamics are undergoing substantial changes because of the activity of the mainly European lumbricid species. Documented losses in litter layers, expansion of A-horizons, loss of the organic horizon, changes in fine root density, and shifts in microbial populations have all been documented in invaded zones. Two free air CO2 enrichment (FACE) forest experiments (aspen FACE at Rhinelander, Wisconsin and sweet gum FACE at Oak Ridge National Lab, Tennessee) lie within the zones of invasion and exhibit differences in amounts of exotic and native species as well as endogeic (predominantly mineral soil dwelling) and epigeic (litter and organic matter horizon dwelling) types. Considerations of carbon accrual dynamics and relative input of above vs. below ground plant input in these young successional systems do not consider the potential impact of these ecosystem engineers. We investigated the impact of earthworm activity by tracking the relative abundance and stable carbon isotope compositions of lignin and substituted fatty acids extracted from isolated earthworms and their fecal pellets and from host soils. Indications of root vs leaf input to earthworm casts and fecal matter were derived from differences in the chemical composition of cutin, suberin, and lignin. The isotopically depleted CO2 used in FACE and the resulting isotopically depleted plant organic matter afford an excellent opportunity to assess biopolymer-specific turnover dynamics. We find that endogeic species are proportionately more responsible for fine root cycling while some epigeic species are responsible for microaggregation of foliar cutin. CSIA of fecal pellet lignin and SFA indicates how these biopolymer pools can be derived from variable sources, roots, background soil, foliar tissue within one earthworm. Additionally, CSIA indicates the distinct roles that different earthworm types have in "aging" surface soil biopolymer pools through encapsulation and upward transport of deeper soil carbon, and "freshening" deeper soil biopolymer pools through downward transport of surface carbon to deeper layers,. As earthworm species abundance and activity are not is steady state in many forests, the role of these important invertebrates should be more considered when assessing the changing soil state.

The Orion Nebula Cluster as a Paradigm of Star Formation

NASA Astrophysics Data System (ADS)

Robberto, Massimo

2014-10-01

We propose a 52-orbit Treasury Program to investigate two fundamental questions of star formation: a) the low-mass tail of the IMF, down to a few Jupiter masses; b) the dynamical evolution of clusters, as revealed by stellar proper motions. We target the Orion Nebula Cluster (ONC) using WFC3 and ACS in coordinated parallel mode to perform a synoptic survey in the 1.345micron H2O feature and Ic broad-band. Our main objectives are: 1) to discover and classify ~500 brown dwarfs and planetary-mass objects in the field, extending the IMF down to lowest masses formed by gravitational collapse. Using the latest generation of high contrast image processing we will also search for faint companions, reaching down to sub-arcsecond separations and 1E-4 flux ratios. 2) to derive high precision (~0.2km/s) relative proper motions of low-mass stars and substellar objects (about 1000 sources total), leveraging on first epoch data obtained by our previous HST Treasury Program about 10 years ago. These data will unveil the cluster dynamics: velocity dispersion vs. mass, substructures, and the fraction of escaping sources. Only HST can access the IR H2O absorption feature sensitive to the effective temperature of substellar objects, while providing the exceptionally stable PSF needed for the detection of faint companions, and the identical ACS platform for our second epoch proper-motion survey. This program will provide the definitive HST legacy dataset on the ONC. Our High-Level Science Products will be mined by the community, both statistically to constrain competing theories of star formation, and to study in depth the multitude of exotic sources harboured by the cluster.

Star Count Density Profiles and Structural Parameters of 26 Galactic Globular Clusters

NASA Astrophysics Data System (ADS)

Miocchi, P.; Lanzoni, B.; Ferraro, F. R.; Dalessandro, E.; Vesperini, E.; Pasquato, M.; Beccari, G.; Pallanca, C.; Sanna, N.

2013-09-01

We used an appropriate combination of high-resolution Hubble Space Telescope observations and wide-field, ground-based data to derive the radial stellar density profiles of 26 Galactic globular clusters from resolved star counts (which can be all freely downloaded on-line). With respect to surface brightness (SB) profiles (which can be biased by the presence of sparse, bright stars), star counts are considered to be the most robust and reliable tool to derive cluster structural parameters. For each system, a detailed comparison with both King and Wilson models has been performed and the most relevant best-fit parameters have been obtained. This collection of data represents the largest homogeneous catalog collected so far of star count profiles and structural parameters derived therefrom. The analysis of the data of our catalog has shown that (1) the presence of the central cusps previously detected in the SB profiles of NGC 1851, M13, and M62 is not confirmed; (2) the majority of clusters in our sample are fit equally well by the King and the Wilson models; (3) we confirm the known relationship between cluster size (as measured by the effective radius) and galactocentric distance; (4) the ratio between the core and the effective radii shows a bimodal distribution, with a peak at ~0.3 for about 80% of the clusters and a secondary peak at ~0.6 for the remaining 20%. Interestingly, the main peak turns out to be in agreement with that expected from simulations of cluster dynamical evolution and the ratio between these two radii correlates well with an empirical dynamical-age indicator recently defined from the observed shape of blue straggler star radial distribution, thus suggesting that no exotic mechanisms of energy generation are needed in the cores of the analyzed clusters.

A high-throughput detection method for invasive fruit fly (Diptera: Tephritidae) species based on microfluidic dynamic array.

PubMed

Jiang, Fan; Fu, Wei; Clarke, Anthony R; Schutze, Mark Kurt; Susanto, Agus; Zhu, Shuifang; Li, Zhihong

2016-11-01

Invasive species can be detrimental to a nation's ecology, economy and human health. Rapid and accurate diagnostics are critical to limit the establishment and spread of exotic organisms. The increasing rate of biological invasions relative to the taxonomic expertise available generates a demand for high-throughput, DNA-based diagnostics methods for identification. We designed species-specific qPCR primer and probe combinations for 27 economically important tephritidae species in six genera (Anastrepha, Bactrocera, Carpomya, Ceratitis, Dacus and Rhagoletis) based on 935 COI DNA barcode haplotypes from 181 fruit fly species publically available in BOLD, and then tested the specificity for each primer pair and probe through qPCR of 35 of those species. We then developed a standardization reaction system for detecting the 27 target species based on a microfluidic dynamic array and also applied the method to identify unknown immature samples from port interceptions and field monitoring. This method led to a specific and simultaneous detection for all 27 species in 7.5 h, using only 0.2 μL of reaction system in each reaction chamber. The approach successfully discriminated among species within complexes that had genetic similarities of up to 98.48%, while it also identified all immature samples consistent with the subsequent results of morphological examination of adults which were reared from larvae of cohorts from the same samples. We present an accurate, rapid and high-throughput innovative approach for detecting fruit flies of quarantine concern. This is a new method which has broad potential to be one of international standards for plant quarantine and invasive species detection. © 2016 John Wiley & Sons Ltd.

Annihilation physics of exotic galactic dark matter particles

NASA Technical Reports Server (NTRS)

Stecker, F. W.

1990-01-01

Various theoretical arguments make exotic heavy neutral weakly interacting fermions, particularly those predicted by supersymmetry theory, attractive candidates for making up the large amount of unseen gravitating mass in galactic halos. Such particles can annihilate with each other, producing secondary particles of cosmic-ray energies, among which are antiprotons, positrons, neutrinos, and gamma-rays. Spectra and fluxes of these annihilation products can be calculated, partly by making use of positron electron collider data and quantum chromodynamic models of particle production derived therefrom. These spectra may provide detectable signatures of exotic particle remnants of the big bang.

Invasive exotic shrub modifies a classic animal-habitat relationship and alters patterns of vertebrate seed predation.

PubMed

Guiden, Peter W; Orrock, John L

2017-02-01

Recent evidence suggests that invasive exotic plants can provide novel habitats that alter animal behavior. However, it remains unclear whether classic animal-habitat associations that influence the spatial distribution of plant-animal interactions, such as small mammal use of downed woody debris, persist in invaded habitats. We removed an invasive exotic shrub (buckthorn, Rhamnus cathartica) from 7 of 15 plots in Wisconsin. In each plot, we deployed 200 tagged Quercus rubra seeds in November 2014. After five months, tags were recovered to track spatial patterns of small mammal seed predation. Most recovered tags were associated with consumed seeds (95%); live-trapping, ancillary camera-trapping, and previous behavioral studies suggest that white-footed mice (Peromyscus leucopus) were responsible for most seed predation. In habitats without R. cathartica, most seed predation occurred near woody debris. In habitats with R. cathartica, small mammals rarely consumed seeds near woody debris, and seed predation occurred farther from the plot center and was less spatially clustered. Our results illustrate that invasive exotic shrubs can disrupt an otherwise common animal-habitat relationship. Failing to account for changes in habitat use may diminish our ability to predict animal distributions and outcomes of species interactions in novel habitats created by invasive exotic plants. © 2016 by the Ecological Society of America.

The ubiquitin ligase Cbl-b limits Pseudomonas aeruginosa exotoxin T-mediated virulence.

PubMed

Balachandran, Priya; Dragone, Leonard; Garrity-Ryan, Lynne; Lemus, Armando; Weiss, Arthur; Engel, Joanne

2007-02-01

Pseudomonas aeruginosa, an important cause of opportunistic infections in humans, delivers bacterial cytotoxins by type III secretion directly into the host cell cytoplasm, resulting in disruption of host cell signaling and host innate immunity. However, little is known about the fate of the toxins themselves following injection into the host cytosol. Here, we show by both in vitro and in vivo studies that the host ubiquitin ligase Cbl-b interacts with the type III-secreted effector exotoxin T (ExoT) and plays a key role in vivo in limiting bacterial dissemination mediated by ExoT. We demonstrate that, following polyubiquitination, ExoT undergoes regulated proteasomal degradation in the host cell cytosol. ExoT interacts with the E3 ubiquitin ligase Cbl-b and Crk, the substrate for the ExoT ADP ribosyltransferase (ADPRT) domain. The efficiency of degradation is dependent upon the activity of the ADPRT domain. In mouse models of acute pneumonia and systemic infection, Cbl-b is specifically required to limit the dissemination of ExoT-producing bacteria whereas c-Cbl plays no detectable role. To the best of our knowledge, this represents the first identification of a mammalian gene product that is specifically required for in vivo resistance to disease mediated by a type III-secreted effector.

The ubiquitin ligase Cbl-b limits Pseudomonas aeruginosa exotoxin T–mediated virulence

PubMed Central

Balachandran, Priya; Dragone, Leonard; Garrity-Ryan, Lynne; Lemus, Armando; Weiss, Arthur; Engel, Joanne

2007-01-01

Pseudomonas aeruginosa, an important cause of opportunistic infections in humans, delivers bacterial cytotoxins by type III secretion directly into the host cell cytoplasm, resulting in disruption of host cell signaling and host innate immunity. However, little is known about the fate of the toxins themselves following injection into the host cytosol. Here, we show by both in vitro and in vivo studies that the host ubiquitin ligase Cbl-b interacts with the type III–secreted effector exotoxin T (ExoT) and plays a key role in vivo in limiting bacterial dissemination mediated by ExoT. We demonstrate that, following polyubiquitination, ExoT undergoes regulated proteasomal degradation in the host cell cytosol. ExoT interacts with the E3 ubiquitin ligase Cbl-b and Crk, the substrate for the ExoT ADP ribosyltransferase (ADPRT) domain. The efficiency of degradation is dependent upon the activity of the ADPRT domain. In mouse models of acute pneumonia and systemic infection, Cbl-b is specifically required to limit the dissemination of ExoT-producing bacteria whereas c-Cbl plays no detectable role. To the best of our knowledge, this represents the first identification of a mammalian gene product that is specifically required for in vivo resistance to disease mediated by a type III–secreted effector. PMID:17235393

Leptogenesis as an origin of hot dark matter and baryon asymmetry in the E6 inspired SUSY models

NASA Astrophysics Data System (ADS)

Nevzorov, R.

2018-04-01

We explore leptogenesis within the E6 inspired U (1) extension of the MSSM in which exact custodial symmetry forbids tree-level flavour-changing transitions and the most dangerous baryon and lepton number violating operators. This supersymmetric (SUSY) model involves extra exotic matter beyond the MSSM. In the simplest phenomenologically viable scenarios the lightest exotic fermions are neutral and stable. These states should be substantially lighter than 1eV forming hot dark matter in the Universe. The low-energy effective Lagrangian of the SUSY model under consideration possesses an approximate global U(1)E symmetry associated with the exotic states. The U(1)E symmetry is explicitly broken because of the interactions between the right-handed neutrino superfields and exotic matter supermultiplets. As a consequence the decays of the lightest right-handed neutrino/sneutrino give rise to both U(1)E and U(1) B - L asymmetries. When all right-handed neutrino/sneutrino are relatively light ∼106-107GeV the appropriate amount of the baryon asymmetry can be induced via these decays if the Yukawa couplings of the lightest right-handed neutrino superfields to the exotic matter supermultiplets vary between ∼10-4-10-3.

Do native parasitic plants cause more damage to exotic invasive hosts than native non-invasive hosts? An implication for biocontrol.

PubMed

Li, Junmin; Jin, Zexin; Song, Wenjing

2012-01-01

Field studies have shown that native, parasitic plants grow vigorously on invasive plants and can cause more damage to invasive plants than native plants. However, no empirical test has been conducted and the mechanism is still unknown. We conducted a completely randomized greenhouse experiment using 3 congeneric pairs of exotic, invasive and native, non-invasive herbaceous plant species to quantify the damage caused by parasitic plants to hosts and its correlation with the hosts' growth rate and resource use efficiency. The biomass of the parasitic plants on exotic, invasive hosts was significantly higher than on congeneric native, non-invasive hosts. Parasites caused more damage to exotic, invasive hosts than to congeneric, native, non-invasive hosts. The damage caused by parasites to hosts was significantly positively correlated with the biomass of parasitic plants. The damage of parasites to hosts was significantly positively correlated with the relative growth rate and the resource use efficiency of its host plants. It may be the mechanism by which parasitic plants grow more vigorously on invasive hosts and cause more damage to exotic, invasive hosts than to native, non-invasive hosts. These results suggest a potential biological control effect of native, parasitic plants on invasive species by reducing the dominance of invasive species in the invaded community.

Minimal Effects of an Invasive Flowering Shrub on the Pollinator Community of Native Forbs

PubMed Central

Chung, Y. Anny; Burkle, Laura A.; Knight, Tiffany M.

2014-01-01

Biological invasions can strongly influence species interactions such as pollination. Most of the documented effects of exotic plant species on plant-pollinator interactions have been observational studies using single pairs of native and exotic plants, and have focused on dominant exotic plant species. We know little about how exotic plants alter interactions in entire communities of plants and pollinators, especially at low to medium invader densities. In this study, we began to address these gaps by experimentally removing the flowers of a showy invasive shrub, Rosa multiflora, and evaluating its effects on the frequency, richness, and composition of bee visitors to co-flowering native plants. We found that while R. multiflora increased plot-level richness of bee visitors to co-flowering native plant species at some sites, its presence had no significant effects on bee visitation rate, visitor richness, bee community composition, or abundance overall. In addition, we found that compared to co-flowering natives, R. multiflora was a generalist plant that primarily received visits from generalist bee species shared with native plant species. Our results suggest that exotic plants such as R. multiflora may facilitate native plant pollination in a community context by attracting a more diverse assemblage of pollinators, but have limited and idiosyncratic effects on the resident plant-pollinator network in general. PMID:25343718

9 CFR 352.1 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Definitions. 352.1 Section 352.1 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.1 Definitions. The...

Fruit flies risk analysis: Current situation and perspectives

USDA-ARS?s Scientific Manuscript database

Trade in fresh agricultural commodities involves probability of entry and establishment of exotic organisms into the importing region or country. The term "risk" includes the product of likelihood that exotic organisms will enter and become established (survive and reproduce) in the importing regio...

Spongeplant Spreading in the Delta

USDA-ARS?s Scientific Manuscript database

Invasive, exotic aquatic plants impact a range of important economic and ecological functions in the Sacramento-San Joaquin Delta of California, and the state now spends over $5 million to control water hyacinth and Brazilian waterweed. In 2007, a new exotic floating plant South American Spongeplan...

Emerging avenues for utilization of exotic germplasm

USDA-ARS?s Scientific Manuscript database

Breeders have been successful in increasing crop performance by exploiting genetic diversity over time. However, the reported annual yield increases are not sufficient in view of rapid human population growth and global environmental changes. Exotic germplasm such as landraces and wild relatives pos...

Sampling seasons for exotic woodboring insects: how long is long enough?

Treesearch

Kathleen J.R. Johnson; James R. LaBonte; Alan D. Mudge; Karl A. Puls

2003-01-01

Several injurious exotic woodboring insects (EWBI) have recently been introduced into North America, such as the Asian longhorned beetle, Anoplophora glabripennis (Motschuslsky) (Coleoptera: Cerambycidae), the brown spruce longhorned beetle, Tetropium fuscum (F.) (Coleoptera: Cerambycidae), and the pine shoot beetle, ...

Electronic and magnetic properties of epitaxial SrRh O 3 films

DOE PAGES

Nichols, John A.; Yuk, Simuck F.; Sohn, Changhee; ...

2017-06-16

The strong interplay of fundamental order parameters in complex oxides is known to give rise to exotic physical phenomena. The 4$d$ transition-metal oxide SrRh O 3 has generated much interest, but advances have been hindered by difficulties in preparing single-crystalline phases. Here we epitaxially stabilize high-quality single-crystalline SrRh O 3 films and investigate their structural, electronic, and magnetic properties. Lastly, we determine that their properties significantly differ from the paramagnetic metallic ground state that governs bulk samples and are strongly related to rotations of Rh O 6 octahedra.

Exotic mitotic mechanisms

PubMed Central

Drechsler, Hauke; McAinsh, Andrew D.

2012-01-01

The emergence of eukaryotes around two billion years ago provided new challenges for the chromosome segregation machineries: the physical separation of multiple large and linear chromosomes from the microtubule-organizing centres by the nuclear envelope. In this review, we set out the diverse solutions that eukaryotic cells use to solve this problem, and show how stepping away from ‘mainstream’ mitosis can teach us much about the mechanisms and mechanics that can drive chromosome segregation. We discuss the evidence for a close functional and physical relationship between membranes, nuclear pores and kinetochores in generating the forces necessary for chromosome segregation during mitosis. PMID:23271831

The expanding universe of alkaloid biosynthesis.

PubMed

De Luca, V; Laflamme, P

2001-06-01

Characterization of many of the major gene families responsible for the generation of central intermediates and for their decoration, together with the development of large genomics and proteomics databases, has revolutionized our capability to identify exotic and interesting natural-product pathways. Over the next few years, these tools will facilitate dramatic advances in our knowledge of the biosynthesis of alkaloids, which will far surpass that which we have learned in the past 50 years. These tools will also be exploited for the rapid characterization of regulatory genes, which control the development of specialized cell factories for alkaloid biosynthesis.

Invasive plants on disturbed Korean sand dunes

NASA Astrophysics Data System (ADS)

Kim, Kee Dae

2005-01-01

The sand dunes in coastal regions of South Korea are important ecosystems because of their small size, the rare species found in this habitat, and the beautiful landscapes they create. This study investigated the current vegetative status of sand dunes on three representative coasts of the Korean peninsula, and on the coasts of Cheju Island, and assessed the conditions caused by invasive plants. The relationships between the degree of invasion and 14 environmental variables were studied. Plots of sand dunes along line transects perpendicular to the coastal lines were established to estimate vegetative species coverage. TWINSPAN (Two-Way Indicator Species Analysis), CCA (Canonical Correspondence Analysis), and DCCA (Detrended Canonical Correspondence Analysis) were performed to classify communities on sand dunes and assess species composition variation. Carex kobomugi, Elymus mollis, and Vitex rotundifolia were found to be the dominant species plotted on the east, the west, and the peripheral coasts of Cheju Island, respectively. Vegetation on the south coast was totally extinct. The 19 communities, including representative C. kobomugi, C. kobomugi- Ixeris repens, C. kobomugi- Oenothera biennis, E. mollis, Lolium multiflorum- Calystegia soldanella, and V. rotundifolia- C. kobomugi, were all classified according to TWINSPAN. Oenothera biennis and L. multiflorum were exotics observed within these native communities. CCA showed that invasive native and exotic species distribution was segregated significantly, according to disturbance level, exotic species number, gravel, sand and silt contents, as well as vegetation size. It further revealed that human disturbance can strongly favor the settlement of invasive and exotic species. Restoration options to reduce exotic plants in the South Korean sand dune areas were found to be the introduction of native plant species from one sand dune into other sand dune areas, prohibition of building and the introduction of exotic soils, and conservation of surrounding sand dune areas.

The influence of soil resources and plant traits on invasion and restoration in a subtropical woodland

USGS Publications Warehouse

Yelenik, Stephanie G.; D'Antonio, Carla M.; August-Schmidt, Elizabeth

2017-01-01

It has been shown in some cases that nitrogen (N) addition to soil will increase abundance of plant invaders because many invaders have traits that promote rapid growth in response to high resource supply. Similarly, it has been suggested, and sometimes shown, that decreasing soil N via carbon (C) additions can facilitate native species recovery. Yet all species are unlikely to respond to resource supply in the same way. We asked how soil nutrients and competition affect native and exotic woody species in a restoration experiment where we added N or C, and crossed soil manipulation with the manipulation of dominant exotic grass abundance in a Hawaiian subtropical woodland. We related changes in survival and growth of outplanted individuals to native/exotic status and plant traits. As a group, N-fixers showed reduced survival compared to non-fixers in response to added N, with Morella faya (exotic) and Acacia koa (native) having dramatic negative responses. Among non-fixers, species with greater foliar %N had more positive survival responses to increasing soil N. Specific leaf area was not predictive of responses to nutrients or competition. In general, responses to carbon addition were weak, although reducing competition from existing exotic grasses was beneficial for all outplanted species, with N-fixers showing the most positive response. We conclude that commonly used restoration strategies to clear exotic species or lower soil resources with C addition will most greatly benefit N-fixing species, which themselves may be unwanted invaders. Thus statements about the influence of increased soil N on invasions should be carefully dissected by considering the traits (such as N-fixation status) of the regional species pool.

Spectroscopic study of excitations in pi-conjugated polymers

NASA Astrophysics Data System (ADS)

Yang, Cungeng

This dissertation deals with spin-physics of photo excitations in pi-conjugated polymers. Optical and magneto-optical spectroscopies, including continuous wave and time-resolved photo-induced absorption, photoluminescence, electroluminescence, and their optically detected magnetic resonance, were used to study steady state and transient photogeneration, energy transfer, spin relaxation, and spin dependent recombination process in the time domain from tens of nanoseconds to tens of milliseconds in polymer materials including regio-random poly (3-hexyl-thiophene-2,5-diyl), regio-regular poly (3-hexyl-thiophene-2,5-diyl), poly (9,9-dioctyl-fluorenyl-2,7-diyl), poly (poly (2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene) of various morphologies, and transition metal complex poly (Pt-quinoxene). Our studies provided the tools to clarify the physical pictures regarding two types of long-lived photoexcitations, namely polarons (both germinate polaron-pairs, and unpaired polarons) and triplet excitons, which are the major excitations in these exotic semiconductors in electrical and optical related applications. From measurements of transient fluorescence and transient fluorescence detected magnetic resonance we show that photogenerated geminate polaron pairs live up to hundreds of microseconds following laser pulsed excitation. This conclusion is in agreement with the delayed formation of triplet excitons that we measured by transient photoinduced absorption. It also agrees with the weak spin-lattice relaxation rate in polymers that we measured using the optically detected magnetic resonance dynamic in thin films and organic light emitting devices. Randomly captured nongeminate polaron pairs were shown to be the major source of optically detected magnetic resonance signal at steady, state. We found that the dynamics and magnitude of the signal depend on the spin-relaxation rate, generation rate and decay rate of the geminate pairs and nongeminate pairs. Importantly we found that the spin-relaxation rate depends weakly on temperature and strongly on coupled heavy atom orbital and magnetic momentum dipole induced by dopants or high intensity excitation. Also the polaron generation rate is excitation energy and nano-morphology dependent; whereas the polaron decay rate is morphology and spin dependent.

9 CFR 352.17 - Transportation.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Transportation. 352.17 Section 352.17 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.17 Transportation. This shall...

9 CFR 352.17 - Transportation.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Transportation. 352.17 Section 352.17 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.17 Transportation. This shall...

9 CFR 352.17 - Transportation.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Transportation. 352.17 Section 352.17 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.17 Transportation. This shall...

9 CFR 352.17 - Transportation.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Transportation. 352.17 Section 352.17 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.17 Transportation. This shall...

Risk and pathway assessment for the introduction of exotic insects and pathogens that could affect Hawai'i's native forests

Treesearch

Gregg A. DeNitto; Philip Cannon; Andris Eglitis; Jessie A. Glaeser; Helen Maffei; Sheri Smith

2015-01-01

The unmitigated risk potential of the introduction of exotic insects and pathogens to Hawai'i was evaluated for its impact on native plants, specifically Acacia koa, Cibotium spp., Dicranopteris linearis, Diospyros sandwicensis, Dodonaea viscosa, ...

Biodiversity maintenance mechanisms differ between native and exotic communities

USDA-ARS?s Scientific Manuscript database

The ongoing homogenization of Earth’s biota is affecting nearly every region of the globe. Grasslands contain perhaps the most disrupted and homogenized communities. We studied 9-species plant communities containing all exotic (i.e. introduced) or all native species under controlled field conditio...

Tamarix (Tamaricaceae) hybrids: most dominant invasive genotype in southern Africa

USDA-ARS?s Scientific Manuscript database

Hybridization can potentially enhance invasiveness. Tamarix (Tamaricaceae) hybrids appear to be the dominant genotypes in their invasions. Exotic Tamarix are declared invasive in South Africa and the exotic T. chinensis and T. ramosissima are known to hybridize between themselves, and with the nativ...

Measurement, analysis, and depiction of activity in adult mosquito populations

USDA-ARS?s Scientific Manuscript database

Globalization, open trading practices, and climate change increase the likelihood of introduction of exotic mosquito species. These mosquitoes may harbor disease agents that threaten public and animal health. Successful containment and eradication of exotic mosquito species and (in the case of exo...

Fatalities due to indigenous and exotic species in Florida.

PubMed

Wolf, Barbara C; Harding, Brett E

2014-01-01

Florida's climate is suitable for many potentially hazardous animals, including both indigenous and exotic species, which are frequently kept as in zoos or as pets. This has resulted in many unforeseen fatal encounters between animals and the ever expanding human population. While the literature and knowledge pool for more common types of deaths referred to medical examiner/coroner's offices is abundant, the appreciation of wildlife and exotic pet-related deaths is far less widespread. We report seven animal attack-related deaths that occurred in Florida. The inflicted injuries included blunt and sharp force injuries, asphyxia, drowning, and envenomation. The underlying cause of death, however, was always a result of the human/animal interaction and in many cases related to human error and failure to appreciate the potentially dangerous behavior of nondomesticated species. These cases illustrate the varied circumstances and pathophysiologies associated with deaths due to indigenous and exotic species and the importance of the multidisciplinary approach in the medicolegal investigation of these cases. © 2013 American Academy of Forensic Sciences.

Faddeev–Jackiw quantization of an Abelian and non-Abelian exotic action for gravity in three dimensions

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

Escalante, Alberto, E-mail: aescalan@ifuap.buap.mx; Manuel-Cabrera, J., E-mail: jmanuel@ifuap.buap.mx

2015-10-15

A detailed Faddeev–Jackiw quantization of an Abelian and non-Abelian exotic action for gravity in three dimensions is performed. We obtain for the theories under study the constraints, the gauge transformations, the generalized Faddeev–Jackiw brackets and we perform the counting of physical degrees of freedom. In addition, we compare our results with those found in the literature where the canonical analysis is developed, in particular, we show that both the generalized Faddeev–Jackiw brackets and Dirac’s brackets coincide to each other. Finally we discuss some remarks and prospects. - Highlights: • A detailed Faddeev–Jackiw analysis for exotic action of gravity is performed.more » • We show that Dirac’s brackets and Generalized [FJ] brackets are equivalent. • Without fixing the gauge exotic action is a non-commutative theory. • The fundamental gauge transformations of the theory are found. • Dirac and Faddeev–Jackiw approaches are compared.« less

In-pile tritium-permeation measurements on T91 tubes with double walls or a Fe-Al/Al 2O 3 coating

NASA Astrophysics Data System (ADS)

Conrad, R.; Bakker, K.; Chabrol, C.; Fütterer, M. A.; van der Laan, J. G.; Rigal, E.; Stijkel, M. P.

2000-12-01

Two new irradiation projects are being performed at the HFR Petten, named EXOTIC-8.9 and EXOTIC-8.10. Issues such as tritium release from candidate ceramic breeder pebbles for the HCPB blanket and tritium permeation through cooling tubes of the WCLL blanket are investigated simultaneously. In EXOTIC-8.9, the tritium release behaviour of a Li 2TiO 3 pebble bed is measured along with the tritium-permeation rate through a double-wall tube (DWT) of T91 with a Cu interlayer. In EXOTIC-8.10, the tritium release behaviour of a Li 4SiO 4 pebble bed is measured along with the tritium permeation rate through a T91 tube with a Fe-Al/Al 2O 3 coating as tritium permeation barrier (TPB). Tritium permeation phenomena are studied by variations of temperatures and purge gas conditions. This paper reports on the results of the first 100 irradiation days.

Looking for Strange Quark Matter in Cosmic Rays.

NASA Astrophysics Data System (ADS)

Shaulov, S. B.; Bezshapov, S. P.

2013-06-01

Usually it is supposed that the definition of the CR mass composition in knee region is the key to problem of CR spectrum modification in this range. However tens of the experiments were done for the last half of century and have not decided this problem up to now. The possible causes of fiasco and arguments in favour of necessity to reformulate attack method are discussed, taking into account a new experimental data about fine structure of CR spectrum and EAS core investigations. The possible presence of the exotic processes in the area of a knee is discussed. If exotic component really exists in CR then impossible to formulate correctly more common problem of mass composition without solving this one. It is represented, that the problem of presence of an exotic component in CR should be solved easier than a CR composition problem. The observational basis is discussed. The hypothesis of strange quark matter in CR is suggested for the exotic component.

The Exotic Legume Tree Species Acacia holosericea Alters Microbial Soil Functionalities and the Structure of the Arbuscular Mycorrhizal Community▿

PubMed Central

Remigi, P.; Faye, A.; Kane, A.; Deruaz, M.; Thioulouse, J.; Cissoko, M.; Prin, Y.; Galiana, A.; Dreyfus, B.; Duponnois, R.

2008-01-01

The response of microbial functional diversity as well as its resistance to stress or disturbances caused by the introduction of an exotic tree species, Acacia holosericea, ectomycorrhized or not with Pisolithus albus, was examined. The results show that this ectomycorrhizal fungus promotes drastically the growth of this fast-growing tree species in field conditions after 7 years of plantation. Compared to the crop soil surrounding the A. holosericea plantation, this exotic tree species, associated or not with the ectomycorrhizal symbiont, induced strong modifications in soil microbial functionalities (assessed by measuring the patterns of in situ catabolic potential of microbial communities) and reduced soil resistance in response to increasing stress or disturbance (salinity, temperature, and freeze-thaw and wet-dry cycles). In addition, A. holosericea strongly modified the structure of arbuscular mycorrhizal fungus communities. These results show clearly that exotic plants may be responsible for important changes in soil microbiota affecting the structure and functions of microbial communities. PMID:18203858

An overview of the roles and structure of international high-security veterinary laboratories for infectious animal diseases.

PubMed

Murray, P K

1998-08-01

The unique structure, role and operations of government high-security (HS) laboratories which work on animal diseases are described, with particular reference to the laboratories of nine countries. High-security laboratories provide cost-effective insurance against catastrophic losses which could occur following exotic disease outbreaks. The importance of these laboratories is reflected in the fact that several new laboratories have recently been constructed at considerable expense and older facilities have undergone major renovations. Biosecurity is fundamental to the operation of high-security laboratories, so good facility design and microbiological security practices are very important. High-security laboratories conduct exotic disease diagnosis, certification and surveillance, and also perform research into virology, disease pathogenesis and improvements to diagnostic tests and vaccines. The mandate of these laboratories includes the training of veterinarians in the recognition of exotic diseases. One extremely important role is the provision of expert advice on exotic diseases and participation (both nationally and internationally) in policy decisions regarding animal disease issues.

Exotic species enhance response diversity to land-use change but modify functional composition.

PubMed

Stavert, Jamie R; Pattemore, David E; Gaskett, Anne C; Beggs, Jacqueline R; Bartomeus, Ignasi

2017-08-16

Two main mechanisms may buffer ecosystem functions despite biodiversity loss. First, multiple species could share similar ecological roles, thus providing functional redundancy. Second, species may respond differently to environmental change (response diversity). However, ecosystem function would be best protected when functionally redundant species also show response diversity. This linkage has not been studied directly, so we investigated whether native and exotic pollinator species with similar traits (functional redundancy) differed in abundance (response diversity) across an agricultural intensification gradient. Exotic pollinator species contributed most positive responses, which partially stabilized overall abundance of the pollinator community. However, although some functionally redundant species exhibited response diversity, this was not consistent across functional groups and aggregate abundances within each functional group were rarely stabilized. This shows functional redundancy and response diversity do not always operate in concert. Hence, despite exotic species becoming increasingly dominant in human-modified systems, they cannot replace the functional composition of native species. © 2017 The Author(s).

Information-based models for finance and insurance

NASA Astrophysics Data System (ADS)

Hoyle, Edward

2010-10-01

In financial markets, the information that traders have about an asset is reflected in its price. The arrival of new information then leads to price changes. The `information-based framework' of Brody, Hughston and Macrina (BHM) isolates the emergence of information, and examines its role as a driver of price dynamics. This approach has led to the development of new models that capture a broad range of price behaviour. This thesis extends the work of BHM by introducing a wider class of processes for the generation of the market filtration. In the BHM framework, each asset is associated with a collection of random cash flows. The asset price is the sum of the discounted expectations of the cash flows. Expectations are taken with respect (i) an appropriate measure, and (ii) the filtration generated by a set of so-called information processes that carry noisy or imperfect market information about the cash flows. To model the flow of information, we introduce a class of processes termed Lévy random bridges (LRBs), generalising the Brownian and gamma information processes of BHM. Conditioned on its terminal value, an LRB is identical in law to a Lévy bridge. We consider in detail the case where the asset generates a single cash flow X_T at a fixed date T. The flow of information about X_T is modelled by an LRB with random terminal value X_T. An explicit expression for the price process is found by working out the discounted conditional expectation of X_T with respect to the natural filtration of the LRB. New models are constructed using information processes related to the Poisson process, the Cauchy process, the stable-1/2 subordinator, the variance-gamma process, and the normal inverse-Gaussian process. These are applied to the valuation of credit-risky bonds, vanilla and exotic options, and non-life insurance liabilities.

Correlates of current transactional sex among a sample of female exotic dancers in Baltimore, MD.

PubMed

Reuben, Jacqueline; Serio-Chapman, Chris; Welsh, Christopher; Matens, Richard; Sherman, Susan G

2011-04-01

Transactional sex work, broadly defined as the exchange of money, drugs, or goods for sexual services, occurs in a wide range of environments. There is a large body of research characterizing the risks and harms associated with street- and venue-based sex work, but there is a dearth of research characterizing the risk associated with the environment of exotic dance clubs. The current study aimed to: (1) characterize the nature of female exotic dancers' sex- and drug-related risk behaviors, (2) to examine the role of the club environment in these behaviors, and (3) to examine correlates of currently exchanging sex. From June 2008 to February 2009, we conducted a cross-sectional study among women who were aged 18 years or older and reported exotic dancing within the past 3 months (n = 98). The survey ascertained socio-demographic characteristics, personal health, medical history, sexual practices, drug use, and employment at clubs on the block. Bivariate and multivariate Poisson regression with robust variance was used to identify correlates of current sex exchange. Participants were a median of 24 years old, and were 58% white; 43% had not completed high school. Seventy-four percent reported ever having been arrested. Twenty-six percent reported having injected heroin and 29% reported having smoked crack in the past 3 months. Fifty-seven percent reported using drugs in the club in the past 3 months. Sixty-one percent had ever engaged in transactional sex, and 67% of those did so for the first time after beginning to dance. Forty-three percent reported selling any sex in the club in the past 3 months. In multiple Poisson regression, factors associated with current sex exchange included: race, ever having been arrested, and using drugs in the club. High levels of both drug use and transactional sex among this sample of exotic dancers were reported. These findings indicate that there are a number of drug- and sex-related harms faced by exotic dancers in strip clubs, implicating the environment in the promotion of HIV/STI risk-taking behaviors. Prevention and intervention programs targeting this population are needed to reduce the harms faced by exotic dancers in this environment.

The fluctuating resource hypothesis explains invasibility, but not exotic advantage following disturbance.

PubMed

Pearson, Dean E; Ortega, Yvette K; Villarreal, Diego; Lekberg, Ylva; Cock, Marina C; Eren, Özkan; Hierro, José L

2018-06-01

Invasibility is a key indicator of community susceptibility to changes in structure and function. The fluctuating resource hypothesis (FRH) postulates that invasibility is an emergent community property, a manifestation of multiple processes that cannot be reliably predicted by individual community attributes like diversity or productivity. Yet, research has emphasized the role of these individual attributes, with the expectation that diversity should deter invasibility and productivity enhance it. In an effort to explore how these and other factors may influence invasibility, we evaluated the relationship between invasibility and species richness, productivity, resource availability, and resilience in experiments crossing disturbance with exotic seed addition in 1-m 2 plots replicated over large expanses of grasslands in Montana, USA and La Pampa, Argentina. Disturbance increased invasibility as predicted by FRH, but grasslands were more invasible in Montana than La Pampa whether disturbed or not, despite Montana's higher species richness and lower productivity. Moreover, invasibility correlated positively with nitrogen availability and negatively with native plant cover. These patterns suggested that resource availability and the ability of the community to recover from disturbance (resilience) better predicted invasibility than either species richness or productivity, consistent with predictions from FRH. However, in ambient, unseeded plots in Montana, disturbance reduced native cover by >50% while increasing exotic cover >200%. This provenance bias could not be explained by FRH, which predicts that colonization processes act on species' traits independent of origins. The high invasibility of Montana grasslands following disturbance was associated with a strong shift from perennial to annual species, as predicted by succession theory. However, this shift was driven primarily by exotic annuals, which were more strongly represented than perennials in local exotic vs. native species pools. We attribute this provenance bias to extrinsic biogeographic factors such as disparate evolutionary histories and/or introduction filters selecting for traits that favor exotics following disturbance. Our results suggest that (1) invasibility is an emergent property best explained by a community's efficiency in utilizing resources, as predicted by FRH but (2) understanding provenance biases in biological invasions requires moving beyond FRH to incorporate extrinsic biogeographic factors that may favor exotics in community assembly. © 2018 by the Ecological Society of America.

Disturbance by an endemic rodent in an arid shrubland is a habitat filter: effects on plant invasion and taxonomical, functional and phylogenetic community structure.

PubMed

Escobedo, Víctor M; Rios, Rodrigo S; Salgado-Luarte, Cristian; Stotz, Gisela C; Gianoli, Ernesto

2017-03-01

Disturbance often drives plant invasion and may modify community assembly. However, little is known about how these modifications of community patterns occur in terms of taxonomic, functional and phylogenetic structure. This study evaluated in an arid shrubland the influence of disturbance by an endemic rodent on community functional divergence and phylogenetic structure as well as on plant invasion. It was expected that disturbance would operate as a habitat filter favouring exotic species with short life cycles. Sixteen plots were sampled along a disturbance gradient caused by the endemic fossorial rodent Spalacopus cyanus , measuring community parameters and estimating functional divergence for life history traits (functional dispersion index) and the relative contribution to functional divergence of exotic and native species. The phylogenetic signal (Pagel's lambda) and phylogenetic community structure (mean phylogenetic distance and mean nearest taxon phylogenetic distance) were also estimated. The use of a continuous approach to the disturbance gradient allowed the identification of non-linear relationships between disturbance and community parameters. The relationship between disturbance and both species richness and abundance was positive for exotic species and negative for native species. Disturbance modified community composition, and exotic species were associated with more disturbed sites. Disturbance increased trait convergence, which resulted in phylogenetic clustering because traits showed a significant phylogenetic signal. The relative contribution of exotic species to functional divergence increased, while that of natives decreased, with disturbance. Exotic and native species were not phylogenetically distinct. Disturbance by rodents in this arid shrubland constitutes a habitat filter over phylogeny-dependent life history traits, leading to phylogenetic clustering, and drives invasion by favouring species with short life cycles. Results can be explained by high phenotypic and phylogenetic resemblance between exotic and native species. The use of continuous gradients when studying the effects of disturbance on community assembly is advocated. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

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

Briceno, Raul A.; Cohen, Thomas D.; Coito, S.

The last few years have been witness to a proliferation of new results concerning heavy exotic hadrons. Experimentally, many new signals have been discovered that could be pointing towards the existence of tetraquarks, pentaquarks, and other exotic configurations of quarks and gluons. Theoretically, advances in lattice field theory techniques place us at the cusp of understanding complex coupled-channel phenomena, modelling grows more sophisticated, and effective field theories are being applied to an ever greater range of situations. Consequently, it is thus an opportune time to evaluate the status of the field. In the following, a series of high priority experimentalmore » and theoretical issues concerning heavy exotic hadrons is presented.« less

Complex Dynamical Networks Constructed with Fully Controllable Nonlinear Nanomechanical Oscillators.

PubMed

Fon, Warren; Matheny, Matthew H; Li, Jarvis; Krayzman, Lev; Cross, Michael C; D'Souza, Raissa M; Crutchfield, James P; Roukes, Michael L

2017-10-11

Control of the global parameters of complex networks has been explored experimentally in a variety of contexts. Yet, the more difficult prospect of realizing arbitrary network architectures, especially analog physical networks that provide dynamical control of individual nodes and edges, has remained elusive. Given the vast hierarchy of time scales involved, it also proves challenging to measure a complex network's full internal dynamics. These span from the fastest nodal dynamics to very slow epochs over which emergent global phenomena, including network synchronization and the manifestation of exotic steady states, eventually emerge. Here, we demonstrate an experimental system that satisfies these requirements. It is based upon modular, fully controllable, nonlinear radio frequency nanomechanical oscillators, designed to form the nodes of complex dynamical networks with edges of arbitrary topology. The dynamics of these oscillators and their surrounding network are analog and continuous-valued and can be fully interrogated in real time. They comprise a piezoelectric nanomechanical membrane resonator, which serves as the frequency-determining element within an electrical feedback circuit. This embodiment permits network interconnections entirely within the electrical domain and provides unprecedented node and edge control over a vast region of parameter space. Continuous measurement of the instantaneous amplitudes and phases of every constituent oscillator node are enabled, yielding full and detailed network data without reliance upon statistical quantities. We demonstrate the operation of this platform through the real-time capture of the dynamics of a three-node ring network as it evolves from the uncoupled state to full synchronization.

Exotic weevil invasion increases floral herbivore community density, function, and impact on a native plant

USDA-ARS?s Scientific Manuscript database

Consumer communities are being re-arranged through unprecedented rates of human-mediated invasions and extinctions. Such changes in consumer composition and diversity potentially alter pressure and impact on resource populations. Although insect herbivore invasions are common, and exotic herbivores...

9 CFR 352.16 - Exports.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Exports. 352.16 Section 352.16 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION... CERTIFICATION EXOTIC ANIMALS AND HORSES; VOLUNTARY INSPECTION Exotic Animals § 352.16 Exports. This shall be...

Invasion of shrublands by exotic grasses: Ecohydrological consequences in cold vs. warm deserts

USDA-ARS?s Scientific Manuscript database

Across the globe, native savannas and woodlands are undergoing conversion to exotic grasslands. Here we summarize the current state of knowledge concerning the ecohydrological consequences of this conversion for the cold deserts (Great Basin, Colorado Plateau) and the warm deserts (Mojave, Sonoran, ...

Exotic invasive plants

Treesearch

Carolyn Hull Sieg; Barbara G. Phillips; Laura P. Moser

2003-01-01

Ecosystems worldwide are threatened by nonnative plant invasions that can cause undesirable, irreversible changes. They can displace native plants and animals, out-cross with native flora, alter nutrient cycling and other ecosystem functions, and even change an ecosystem's flammability (Walker and Smith 1997). After habitat loss, the spread of exotic species is...

Biological Control of Southern Pine Beetle

Treesearch

Fred M. Stephen; C. Wayne Berisford

2011-01-01

Exotic invasive forest insects are frequently managed through classical biological control, which involves searching for, introducing, and establishing their exotic natural enemies. Biological control of native bark beetles, including the southern pine beetle (SPB), has been primarily attempted by conserving and manipulating their natural enemies. Knowledge of the role...

Eradication of an exotic ambrosia beetle, Xylosandrus crassiusculus (Motschulsky), in Oregon

Treesearch

James R. LaBonte

2011-01-01

The Oregon Department of Agriculture (ODA) has been monitoring an industrial plant in The Dalles, OR, for exotic wood boring insects since 1998. This plant receives raw railroad ties from British Columbia and several localities in the United States, including Arkansas, Missouri, and Texas.

Cercopithecine herpesvirus 1 risk in a child bitten by a Bonnet Macaque monkey.

PubMed

Tregle, Rodney William; Loe, Catherine Lindsay; Earhart, Robert Hailes; d'Autremont, Sarah Baillio

2011-10-01

Exotic animal importation and trade has the potential to expose the public to a variety of injuries and diseases not endemic to the United States. Bonnet Macaque monkeys are a fairly common primate illegally held in captivity. These monkeys become aggressive as they age past 2 years and are known to carry asymptomatic Cercopithecine herpesvirus 1 infection. This case is presented to illustrate the point that simple wound management alone may not only be insufficient but could be fatal in certain exotic animal bites and that the emergency physician should consult with authorities familiar with exotic animals when treating a patient with an exotic animal bite. We present the case of a 2-year-old child that was bitten by his neighbor's pet Bonnet Macaque monkey. This species of Old World monkey carries the Cercopithecine herpesvirus 1 (simian B virus) 73-100% of the time. This infection in humans can lead to an encephalitis that has a 70% mortality rate. Consultation with animal authorities led to the proper treatment, which included routine wound care, rabies prophylaxis, irrigation with sodium hypochlorite solution, and treatment with antiviral medication. Simple wound management alone may not be enough in patients bitten by exotic animals. Consultation with local zoo officials, veterinary medical schools, or the Centers for Disease Control and Prevention is recommended in these cases. Copyright © 2011 Elsevier Inc. All rights reserved.

BBN for the LHC: Constraints on lifetimes of the Higgs portal scalars

NASA Astrophysics Data System (ADS)

Fradette, Anthony; Pospelov, Maxim

2017-10-01

LHC experiments can provide a remarkable sensitivity to exotic metastable massive particles, decaying with significant displacement from the interaction point. The best sensitivity is achieved with models where the production and decay occur due to different coupling constants, and the lifetime of exotic particles determines the probability of decay within a detector. The lifetimes of such particles can be independently limited from standard cosmology, in particular, the big bang nucleosynthesis (BBN). In this paper, we analyze the constraints on the simplest scalar model coupled through the Higgs portal, where the production occurs via h →S S , and the decay is induced by the small mixing angle of the Higgs field h and scalar S . We find that throughout most of the parameter space, 2 mμ

The international trade in reptiles (Reptilia)--the cause of the transfer of exotic ticks (Acari: Ixodida) to Poland.

PubMed

Nowak, Magdalena

2010-05-11

The problem of the unnatural transfer of exotic ticks (Acari: Ixodida) on reptiles (Reptilia) imported to Poland is presented. In the period from 2003 to 2007, 382 specimens of reptiles belonging to the following genera were investigated: Testudo, Iguana, Varanus, Gongylophis, Python, Spalerosophis, Psammophis. The reptiles most infested with ticks are imported to Poland from Ghana in Africa, and are the commonly bred terrarium reptiles: Varanus exanthematicus and Python regius. As a result of the investigations, the transfer of exotic ticks on reptiles to Poland was confirmed. There were 2104 specimens of the genera Amblyomma and Hyalomma. The following species were found: Amblyomma exornatum Koch, 1844, Amblyomma flavomaculatum (Lucas, 1846), Amblyomma latum Koch, 1844, Amblyomma nuttalli Donitz, 1909, Amblyomma quadricavum (Schulze, 1941), Amblyomma transversale (Lucas, 1844), Amblyomma varanense (Supino, 1897), Amblyomma sp. Koch, 1844, Hyalomma aegyptium (Linnaeus, 1758). All the species of ticks of genus Amblyomma revealed have been discovered in Poland for the first time. During the research, 13 cases of anomalies of morphological structure were confirmed in the ticks A. flavomaculatum, A. latum and H. aegyptium. The expanding phenomenon of the import of exotic reptiles in Poland and Central Europe is important for parasitological and epidemiological considerations, and therefore requires monitoring and wide-ranging prophylactic activities to prevent the inflow of exotic parasites to Poland. (c) 2010 Elsevier B.V. All rights reserved.

Do Native Parasitic Plants Cause More Damage to Exotic Invasive Hosts Than Native Non-Invasive Hosts? An Implication for Biocontrol

PubMed Central

Li, Junmin; Jin, Zexin; Song, Wenjing

2012-01-01

Field studies have shown that native, parasitic plants grow vigorously on invasive plants and can cause more damage to invasive plants than native plants. However, no empirical test has been conducted and the mechanism is still unknown. We conducted a completely randomized greenhouse experiment using 3 congeneric pairs of exotic, invasive and native, non-invasive herbaceous plant species to quantify the damage caused by parasitic plants to hosts and its correlation with the hosts' growth rate and resource use efficiency. The biomass of the parasitic plants on exotic, invasive hosts was significantly higher than on congeneric native, non-invasive hosts. Parasites caused more damage to exotic, invasive hosts than to congeneric, native, non-invasive hosts. The damage caused by parasites to hosts was significantly positively correlated with the biomass of parasitic plants. The damage of parasites to hosts was significantly positively correlated with the relative growth rate and the resource use efficiency of its host plants. It may be the mechanism by which parasitic plants grow more vigorously on invasive hosts and cause more damage to exotic, invasive hosts than to native, non-invasive hosts. These results suggest a potential biological control effect of native, parasitic plants on invasive species by reducing the dominance of invasive species in the invaded community. PMID:22493703

Compensation and exotic livestock disease management: the views of animal keepers and veterinarians in England.

PubMed

Hamilton-Webb, A; Naylor, R; Little, R; Maye, D

2016-11-19

Relatively little is known about the perceived influence of different compensation systems on animal keepers' management of exotic livestock disease. This paper aims to address this research gap by drawing on interviews with 61 animal keepers and 21 veterinarians, as well as a series of nine animal keeper focus groups across five different livestock sectors in England. The perceived influence of current compensation systems on disease control behaviour was explored and alternative compensation systems that respectively reward positive practices and penalise poor practices were presented in the form of scenarios, alongside a third system that considered the option of a cost-sharing levy system between industry and government. The results indicate that animal keepers consider themselves to be influenced by a range of non-financial factors, for example, feelings of responsibility, reputation and animal welfare concerns, in the context of their exotic disease management practices. The majority of animal keepers were unaware of the current compensation systems in place for exotic diseases, and were therefore not consciously influenced by financial recompense. Concerns were raised about linking compensation to disease management behaviour due to auditing difficulties. A cost-sharing levy system would likely raise awareness of exotic disease and compensation among animal keepers, but differentiation of payments based upon individual farm-level risk assessments was called for by participants as a strategy to promote positive disease management practices. British Veterinary Association.

Past and future detector arrays for complete event reconstruction in heavy-ion reactions

NASA Astrophysics Data System (ADS)

Cardella, G.; Acosta, L.; Auditore, L.; Boiano, C.; Castoldi, A.; D'Andrea, M.; De Filippo, E.; Dell'Aquila, D.; De Luca, S.; Fichera, F.; Giudice, N.; Gnoffo, B.; Grimaldi, A.; Guazzoni, C.; Lanzalone, G.; Librizzi, F.; Lombardo, I.; Maiolino, C.; Maffesanti, S.; Martorana, N. S.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Parsani, T.; Passaro, G.; Pirrone, S.; Politi, G.; Previdi, F.; Quattrocchi, L.; Rizzo, F.; Russotto, P.; Saccà, G.; Salemi, G.; Sciliberto, D.; Trifirò, A.; Trimarchi, M.; Vigilante, M.

2017-11-01

Complex and more and more complete detector arrays have been developed in the last two decades, or are in advanced design stage, in different laboratories. Such arrays are necessary to fully characterize nuclear reactions induced by stable and exotic beams. The need for contemporary detection of charged particles, and/or γ -rays, and/or neutrons, has been stressed in many fields of nuclear structure and reaction dynamics, with particular attention to the improvement of both high angular and energy resolution. Some examples of detection systems adapted to various energy ranges is discussed. Emphasis is given to the possible update of relatively old 4π detectors with new electronics and new detection methods.

Geometry in transition in four dimensions: A model of emergent geometry in the early universe

NASA Astrophysics Data System (ADS)

Ydri, Badis; Khaled, Ramda; Ahlam, Rouag

2016-10-01

We study a six matrix model with global S O (3 )×S O (3 ) symmetry containing at most quartic powers of the matrices. This theory exhibits a phase transition from a geometrical phase at low temperature to a Yang-Mills matrix phase with no background geometrical structure at high temperature. This is an exotic phase transition in the same universality class as the three matrix model but with important differences. The geometrical phase is determined dynamically, as the system cools, and is given by a fuzzy sphere background SN2×SN2, with an Abelian gauge field which is very weakly coupled to two normal scalar fields.