Polarizing optics in a spider eye.

PubMed

Mueller, Kaspar P; Labhart, Thomas

2010-05-01

Many arthropods including insects and spiders exploit skylight polarization for navigation. One of the four eye pairs of the spider Drassodes cupreus is dedicated to detect skylight polarization. These eyes are equipped with a tapetum that strongly plane-polarizes reflected light. This effectively enhances the polarization-sensitivity of the photoreceptors, improving orientation performance. With a multidisciplinary approach, we demonstrate that D. cupreus exploits reflective elements also present in non-polarizing tapetal eyes of other species such as Agelena labyrinthica. By approximately orthogonal arrangement of two multilayer reflectors consisting of reflecting guanine platelets, the tapetum uses the mechanism of polarization by reflection for polarizing reflected light.

3D Finite Element Analysis of Spider Non-isothermal Forging Process

NASA Astrophysics Data System (ADS)

Niu, Ling; Wei, Wei; Wei, Kun Xia; Alexandrov, Igor V.; Hu, Jing

2016-06-01

The differences of effective stress, effective strain, velocity field, and the load-time curves between the spider isothermal and non-isothermal forging processes are investigated by making full use of 3D FEA, and verified by the production experiment of spider forging. Effective stress is mainly concentrated on the pin, and becomes lower closer to the front of the pin. The maximum effective strain in the non-isothermal forging is lower than that in the isothermal. The great majority of strain in the non-isothermal forging process is 1.76, which is larger than the strain of 1.31 in the isothermal forging. The maximum load required in the isothermal forging is higher than that in the non-isothermal. The maximum experimental load and deformation temperature in the spider production are in good agreement with those in the non-isothermal FEA. The results indicate that the non-isothermal 3D FEA results can guide the design of the spider forging process.

Synthesis of a Carbon-activated Microfiber from Spider Webs Silk

NASA Astrophysics Data System (ADS)

Taer, E.; Mustika, W. S.; Taslim, R.

2017-03-01

Carbon fiber of spider web silk has been produced through the simple carbonization process. Cobwebs are a source of strong natural fiber, flexible and micrometer in size. Preparation of micro carbon fiber from spider webs that consist of carbonization and activation processes. Carbonization was performed in N2 gas environment by multi step heating profile up to temperature of 400 °C, while the activation process was done by using chemical activation with KOH activating agent assistance. Measurement of physical properties was conducted on the surface morphology, element content and the degree of crystallinity. The measurement results found that micro carbon fiber from spider webs has a diameter in the range of 0.5 -25 micrometers. It is found that the carbon-activated microfiber takes the amorphous form with the carbon content of 84 %.

Complementary microanalysis of Zn, Mn and Fe in the chelicera of spiders and scorpions using scanning MeV-ion and electron microprobes

NASA Astrophysics Data System (ADS)

Schofield, Robert; Lefevre, Harlan; Shaffer, Michael

1989-04-01

Energy-loss scanning transmission ion microscopy (ELSTIM or just STIM), PIXE and electron microprobe techniques are used to investigate certain minor element accumulations in a few spiders and scorpions. STIM and PIXE are used to survey the unsectioned specimens, while electron microprobe techniques are used for higher resolution investigations of several sections of the specimens. Concentration values measured using STIM and PIXE are found to be in satisfactory agreement with those measured using electron probe microanalysis. A garden spider Araneus diadematus is found to contain high concentrations of zinc in a thin layer near the surface of its fangs (reaching 23% of dry weight), and manganese in its marginal teeth (about 5% of dry weight). A wolf spider Alopecosa kochi is found to have similar concentrations of zinc in a layer near the surface of it's fang, and concentrations of manganese reaching 1.5% in a layer beneath the zinc containing layer. A scorpion Centruroides sp. is found to contain high concentrations of iron (reaching 8%) and zinc (reaching 24%) in the tips of teeth on the cheliceral fingers, and manganese (about 5%) in the stinger. The hypothesis that these elements simply harden the cuticle does not appear to explain their segregation patterns.

Atmospheric deposition of rare earth elements in Albania studied by the moss biomonitoring technique, neutron activation analysis and GIS technology.

PubMed

Allajbeu, Sh; Yushin, N S; Qarri, F; Duliu, O G; Lazo, P; Frontasyeva, M V

2016-07-01

Rare earth elements (REEs) are typically conservative elements that are scarcely derived from anthropogenic sources. The mobilization of REEs in the environment requires the monitoring of these elements in environmental matrices, in which they are present at trace level. The determination of 11 REEs in carpet-forming moss species (Hypnum cupressiforme) collected from 44 sampling sites over the whole territory of the country were done by using epithermal neutron activation analysis (ENAA) at IBR-2 fast pulsed reactor in Dubna. This paper is focused on REEs (lanthanides) and Sc. Fe as typical consistent element and Th that appeared good correlations between the elements of lanthanides are included in this paper. Th, Sc, and REEs were never previously determined in the air deposition of Albania. Descriptive statistics were used for data treatment using MINITAB 17 software package. The median values of the elements under investigation were compared with those of the neighboring countries such as Bulgaria, Macedonia, Romania, and Serbia, as well as Norway which is selected as a clean area. Geographical distribution maps of the elements over the sampled territory were constructed using geographic information system (GIS) technology. Geochemical behavior of REEs in moss samples has been studied by using the ternary diagram of Sc-La-Th, Spider diagrams and multivariate analysis. It was revealed that the accumulation of REEs in current mosses is associated with the wind-blowing metal-enriched soils that is pointed out as the main emitting factor of the elements under investigation.

Final design of thermal diagnostic system in SPIDER ion source

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

Brombin, M., E-mail: matteo.brombin@igi.cnr.it; Dalla Palma, M.; Pasqualotto, R.

The prototype radio frequency source of the ITER heating neutral beams will be first tested in SPIDER test facility to optimize H{sup −} production, cesium dynamics, and overall plasma characteristics. Several diagnostics will allow to fully characterise the beam in terms of uniformity and divergence and the source, besides supporting a safe and controlled operation. In particular, thermal measurements will be used for beam monitoring and system protection. SPIDER will be instrumented with mineral insulated cable thermocouples, both on the grids, on other components of the beam source, and on the rear side of the beam dump water cooled elements.more » This paper deals with the final design and the technical specification of the thermal sensor diagnostic for SPIDER. In particular the layout of the diagnostic, together with the sensors distribution in the different components, the cables routing and the conditioning and acquisition cubicles are described.« less

Conceptual design and structural analysis for an 8.4-m telescope

NASA Astrophysics Data System (ADS)

Mendoza, Manuel; Farah, Alejandro; Ruiz Schneider, Elfego

2004-09-01

This paper describes the conceptual design of the optics support structures of a telescope with a primary mirror of 8.4 m, the same size as a Large Binocular Telescope (LBT) primary mirror. The design goal is to achieve a structure for supporting the primary and secondary mirrors and keeping them joined as rigid as possible. With this purpose an optimization with several models was done. This iterative design process includes: specifications development, concepts generation and evaluation. Process included Finite Element Analysis (FEA) as well as other analytical calculations. Quality Function Deployment (QFD) matrix was used to obtain telescope tube and spider specifications. Eight spiders and eleven tubes geometric concepts were proposed. They were compared in decision matrixes using performance indicators and parameters. Tubes and spiders went under an iterative optimization process. The best tubes and spiders concepts were assembled together. All assemblies were compared and ranked according to their performance.

Final design of thermal diagnostic system in SPIDER ion source

NASA Astrophysics Data System (ADS)

Brombin, M.; Dalla Palma, M.; Pasqualotto, R.; Pomaro, N.

2016-11-01

The prototype radio frequency source of the ITER heating neutral beams will be first tested in SPIDER test facility to optimize H- production, cesium dynamics, and overall plasma characteristics. Several diagnostics will allow to fully characterise the beam in terms of uniformity and divergence and the source, besides supporting a safe and controlled operation. In particular, thermal measurements will be used for beam monitoring and system protection. SPIDER will be instrumented with mineral insulated cable thermocouples, both on the grids, on other components of the beam source, and on the rear side of the beam dump water cooled elements. This paper deals with the final design and the technical specification of the thermal sensor diagnostic for SPIDER. In particular the layout of the diagnostic, together with the sensors distribution in the different components, the cables routing and the conditioning and acquisition cubicles are described.

Remote monitoring of vibrational information in spider webs.

PubMed

Mortimer, B; Soler, A; Siviour, C R; Vollrath, F

2018-05-22

Spiders are fascinating model species to study information-acquisition strategies, with the web acting as an extension of the animal's body. Here, we compare the strategies of two orb-weaving spiders that acquire information through vibrations transmitted and filtered in the web. Whereas Araneus diadematus monitors web vibration directly on the web, Zygiella x-notata uses a signal thread to remotely monitor web vibration from a retreat, which gives added protection. We assess the implications of these two information-acquisition strategies on the quality of vibration information transfer, using laser Doppler vibrometry to measure vibrations of real webs and finite element analysis in computer models of webs. We observed that the signal thread imposed no biologically relevant time penalty for vibration propagation. However, loss of energy (attenuation) was a cost associated with remote monitoring via a signal thread. The findings have implications for the biological use of vibrations by spiders, including the mechanisms to locate and discriminate between vibration sources. We show that orb-weaver spiders are fascinating examples of organisms that modify their physical environment to shape their information-acquisition strategy.

Remote monitoring of vibrational information in spider webs

NASA Astrophysics Data System (ADS)

Mortimer, B.; Soler, A.; Siviour, C. R.; Vollrath, F.

2018-06-01

Spiders are fascinating model species to study information-acquisition strategies, with the web acting as an extension of the animal's body. Here, we compare the strategies of two orb-weaving spiders that acquire information through vibrations transmitted and filtered in the web. Whereas Araneus diadematus monitors web vibration directly on the web, Zygiella x-notata uses a signal thread to remotely monitor web vibration from a retreat, which gives added protection. We assess the implications of these two information-acquisition strategies on the quality of vibration information transfer, using laser Doppler vibrometry to measure vibrations of real webs and finite element analysis in computer models of webs. We observed that the signal thread imposed no biologically relevant time penalty for vibration propagation. However, loss of energy (attenuation) was a cost associated with remote monitoring via a signal thread. The findings have implications for the biological use of vibrations by spiders, including the mechanisms to locate and discriminate between vibration sources. We show that orb-weaver spiders are fascinating examples of organisms that modify their physical environment to shape their information-acquisition strategy.

Controlling light with freeform optics: recent progress in computational methods for optical design of freeform lenses with prescribed irradiance properties

NASA Astrophysics Data System (ADS)

Oliker, Vladimir I.; Cherkasskiy, Boris

2014-09-01

Structural color is produced when nanostructures called schemochromes alter light reflected from a surface through different optic principles, in contrast with other types of colors that are produced when pigments selectively absorb certain wavelengths of light. Research on biogenic photonic nanostructures has focused primarily on bird feathers, butterfly wings and beetle elytra, ignoring other diverse groups such as spiders. We argue that spiders are a good model system to study the functions and evolution of colors in nature for the following reasons. First, these colors clearly function in spiders such as the tarantulas outside of sexual selection, which is likely the dominant driver of the evolution of structural colors in birds and butterflies. Second, within more than 44,000 currently known spider species, colors are used in every possible way based on the same sets of relatively simple materials. Using spiders, we can study how colors evolve to serve different functions under a variety of combinations of driving forces, and how those colors are produced within a relatively simple system. Here, we first review the different color-producing materials and mechanisms (i.e., light absorbing, reflecting and emitting) in birds, butterflies and beetles, the interactions between these different elements, and the functions of colors in different organisms. We then summarize the current state of knowledge of spider colors and compare it with that of birds and insects. We then raise questions including: 1. Could spiders use fluorescence as a mechanism to protect themselves from UV radiation, if they do not have the biosynthetic pathways to produce melanins? 2. What functions could color serve for nearly blind tarantulas? 3. Why are only multilayer nanostructures (thus far) found in spiders, while birds and butterflies use many diverse nanostructures? And, does this limit the diversity of structural colors found in spiders? Answering any of these questions in the future will bring spiders to the forefront of the study of structural colors in nature.

Sparse trees and shrubs confers a high biodiversity to pastures: Case study on spiders from Transylvania.

PubMed

Gallé, Róbert; Urák, István; Nikolett, Gallé-Szpisjak; Hartel, Tibor

2017-01-01

The integration of food production and biodiversity conservation represents a key challenge for sustainability. Several studies suggest that even small structural elements in the landscape can make a substantial contribution to the overall biodiversity value of the agricultural landscapes. Pastures can have high biodiversity potential. However, their intensive and monofunctional use typically erodes its natural capital, including biodiversity. Here we address the ecological value of fine scale structural elements represented by sparsely scattered trees and shrubs for the spider communities in a moderately intensively grazed pasture in Transylvania, Eastern Europe. The pasture was grazed with sheep, cattle and buffalo (ca 1 Livestock Unit ha-1) and no chemical fertilizers were applied. Sampling sites covered the open pasture as well as the existing fine-scale heterogeneity created by scattered trees and shrub. 40 sampling locations each being represented by three 1 m2 quadrats were situated in a stratified design while assuring spatial independency of sampling locations. We identified 140 species of spiders, out of which 18 were red listed and four were new for the Romanian fauna. Spider species assemblages of open pasture, scattered trees, trees and shrubs and the forest edge were statistically distinct. Our study shows that sparsely scattered mature woody vegetation and shrubs substantially increases the ecological value of managed pastures. The structural complexity provided by scattered trees and shrubs makes possible the co-occurrence of high spider diversity with a moderately high intensity grazing possible in this wood-pasture. Our results are in line with recent empirical research showing that sparse trees and shrubs increases the biodiversity potential of pastures managed for commodity production.

Sparse trees and shrubs confers a high biodiversity to pastures: Case study on spiders from Transylvania

PubMed Central

Nikolett, Gallé-Szpisjak; Hartel, Tibor

2017-01-01

The integration of food production and biodiversity conservation represents a key challenge for sustainability. Several studies suggest that even small structural elements in the landscape can make a substantial contribution to the overall biodiversity value of the agricultural landscapes. Pastures can have high biodiversity potential. However, their intensive and monofunctional use typically erodes its natural capital, including biodiversity. Here we address the ecological value of fine scale structural elements represented by sparsely scattered trees and shrubs for the spider communities in a moderately intensively grazed pasture in Transylvania, Eastern Europe. The pasture was grazed with sheep, cattle and buffalo (ca 1 Livestock Unit ha-1) and no chemical fertilizers were applied. Sampling sites covered the open pasture as well as the existing fine-scale heterogeneity created by scattered trees and shrub. 40 sampling locations each being represented by three 1 m2 quadrats were situated in a stratified design while assuring spatial independency of sampling locations. We identified 140 species of spiders, out of which 18 were red listed and four were new for the Romanian fauna. Spider species assemblages of open pasture, scattered trees, trees and shrubs and the forest edge were statistically distinct. Our study shows that sparsely scattered mature woody vegetation and shrubs substantially increases the ecological value of managed pastures. The structural complexity provided by scattered trees and shrubs makes possible the co-occurrence of high spider diversity with a moderately high intensity grazing possible in this wood-pasture. Our results are in line with recent empirical research showing that sparse trees and shrubs increases the biodiversity potential of pastures managed for commodity production. PMID:28886058

Spider-web amphiphiles as artificial lipid clusters: design, synthesis, and accommodation of lipid components at the air-water interface.

PubMed

Ariga, Katsuhiko; Urakawa, Toshihiro; Michiue, Atsuo; Kikuchi, Jun-ichi

2004-08-03

As a novel category of two-dimensional lipid clusters, dendrimers having an amphiphilic structure in every unit were synthesized and labeled "spider-web amphiphiles". Amphiphilic units based on a Lys-Lys-Glu tripeptide with hydrophobic tails at the C-terminal and a polar head at the N-terminal are dendrically connected through stepwise peptide coupling. This structural design allowed us to separately introduce the polar head and hydrophobic tails. Accordingly, we demonstrated the synthesis of the spider-web amphiphile series in three combinations: acetyl head/C16 chain, acetyl head/C18 chain, and ammonium head/C16 chain. All the spider-web amphiphiles were synthesized in satisfactory yields, and characterized by 1H NMR, MALDI-TOFMS, GPC, and elemental analyses. Surface pressure (pi)-molecular area (A) isotherms showed the formation of expanded monolayers except for the C18-chain amphiphile at 10 degrees C, for which the molecular area in the condensed phase is consistent with the cross-sectional area assigned for all the alkyl chains. In all the spider-web amphiphiles, the molecular areas at a given pressure in the expanded phase increased in proportion to the number of units, indicating that alkyl chains freely fill the inner space of the dendritic core. The mixing of octadecanoic acid with the spider-web amphiphiles at the air-water interface induced condensation of the molecular area. From the molecular area analysis, the inclusion of the octadecanoic acid bears a stoichiometric characteristic; i.e., the number of captured octadecanoic acids in the spider-web amphiphile roughly agrees with the number of branching points in the spider-web amphiphile.

A New On-Line Diagnosis Protocol for the SPIDER Family of Byzantine Fault Tolerant Architectures

NASA Technical Reports Server (NTRS)

Geser, Alfons; Miner, Paul S.

2004-01-01

This paper presents the formal verification of a new protocol for online distributed diagnosis for the SPIDER family of architectures. An instance of the Scalable Processor-Independent Design for Electromagnetic Resilience (SPIDER) architecture consists of a collection of processing elements communicating over a Reliable Optical Bus (ROBUS). The ROBUS is a specialized fault-tolerant device that guarantees Interactive Consistency, Distributed Diagnosis (Group Membership), and Synchronization in the presence of a bounded number of physical faults. Formal verification of the original SPIDER diagnosis protocol provided a detailed understanding that led to the discovery of a significantly more efficient protocol. The original protocol was adapted from the formally verified protocol used in the MAFT architecture. It required O(N) message exchanges per defendant to correctly diagnose failures in a system with N nodes. The new protocol achieves the same diagnostic fidelity, but only requires O(1) exchanges per defendant. This paper presents this new diagnosis protocol and a formal proof of its correctness using PVS.

Phenotypic integration in a series of trophic traits: tracing the evolution of myrmecophagy in spiders (Araneae).

PubMed

Pekár, Stano; Michalko, Radek; Korenko, Stanislav; Sedo, Ondřej; Líznarová, Eva; Sentenská, Lenka; Zdráhal, Zbyněk

2013-02-01

Several hypotheses have been put forward to explain the evolution of prey specificity (stenophagy). Yet little light has so far been shed on the process of evolution of stenophagy in carnivorous predators. We performed a detailed analysis of a variety of trophic adaptations in one species. Our aim was to determine whether a specific form of stenophagy, myrmecophagy, has evolved from euryphagy via parallel changes in several traits from pre-existing characters. For that purpose, we studied the trophic niche and morphological, behavioural, venomic and physiological adaptations in a euryphagous spider, Selamia reticulata. It is a species that is branching off earlier in phylogeny than stenophagous ant-eating spiders of the genus Zodarion (both Zodariidae). The natural diet was wide and included ants. Laboratory feeding trials revealed versatile prey capture strategies that are effective on ants and other prey types. The performance of spiders on two different diets - ants only and mixed insects - failed to reveal differences in most fitness components (survival and developmental rate). However, the weight increase was significantly higher in spiders on the mixed diet. As a result, females on a mixed diet had higher fecundity and oviposited earlier. No differences were found in incubation period, hatching success or spiderling size. S. reticulata possesses a more diverse venom composition than Zodarion. Its venom is more effective for the immobilisation of beetle larvae than of ants. Comparative analysis of morphological traits related to myrmecophagy in the family Zodariidae revealed that their apomorphic states appeared gradually along the phylogeny to derived prey-specialised genera. Our results suggest that myrmecophagy has evolved gradually from the ancestral euryphagous strategy by integrating a series of trophic traits. Copyright © 2012 Elsevier GmbH. All rights reserved.

Spiders in Lyot Coronagraphs

NASA Astrophysics Data System (ADS)

Sivaramakrishnan, Anand; Lloyd, James P.

2005-11-01

In principle, suppression of on-axis stellar light by a coronagraph is easier on an unobscured aperture telescope than on one with an obscured aperture. Recent designs such as the apodized pupil Lyot coronagraph, the ``band-limited'' Lyot coronagraph, and several variants of phase-mask coronagraphs work best on unobscured circular aperture telescopes. These designs were developed to enable the discovery and characterization of nearby Jovian or even terrestrial exoplanets. All of today's major space-based and adaptive optics-equipped ground-based telescopes are obscured-aperture systems with a secondary mirror held in place by secondary support ``spider'' vanes. The presence of a secondary obscuration can be dealt with by ingenious coronagraph designs, but the spider vanes themselves cause diffracted light, which can hamper the search for Jovian exoplanets around nearby stars. We look at the problem of suppressing spider vane diffraction in Lyot coronagraphs, including apodized pupil and band-limited designs. We show how spider vane diffraction can be reduced drastically and in fact contained in the final coronagraphic image, within one resolution element of the geometric image of the focal plane mask's occulting spot. This makes adaptive optics coronagraphic searches for exojupiters possible with the next generation of adaptive optics systems being developed for 8-10 m class telescopes such as Gemini and the Very Large Telescopes.

Vibration transmission through sheet webs of hobo spiders (Eratigena agrestis) and tangle webs of western black widow spiders (Latrodectus hesperus).

PubMed

Vibert, Samantha; Scott, Catherine; Gries, Gerhard

2016-11-01

Web-building spiders construct their own vibratory signaling environments. Web architecture should affect signal design, and vice versa, such that vibratory signals are transmitted with a minimum of attenuation and degradation. However, the web is the medium through which a spider senses both vibratory signals from courting males and cues produced by captured prey. Moreover, webs function not only in vibration transmission, but also in defense from predators and the elements. These multiple functions may impose conflicting selection pressures on web design. We investigated vibration transmission efficiency and accuracy through two web types with contrasting architectures: sheet webs of Eratigena agrestis (Agelenidae) and tangle webs of Latrodectus hesperus (Theridiidae). We measured vibration transmission efficiencies by playing frequency sweeps through webs with a piezoelectric vibrator and a loudspeaker, recording the resulting web vibrations at several locations on each web using a laser Doppler vibrometer. Transmission efficiencies through both web types were highly variable, with within-web variation greater than among-web variation. There was little difference in transmission efficiencies of longitudinal and transverse vibrations. The inconsistent transmission of specific frequencies through webs suggests that parameters other than frequency are most important in allowing these spiders to distinguish between vibrations of prey and courting males.

Testing of 100 mK bolometers for space applications

NASA Technical Reports Server (NTRS)

Murray, A. G.; Ade, P. A. R.; Bhatia, R. S.; Griffin, M. J.; Maffei, B.; Nartallo, R.; Beeman, J. W.; Bock, J.; Lange, A.; DelCastillo, H.

1996-01-01

Electrical and optical performance data are presented for a prototype 100 mK spider-web bolometer operating under very low photon backgrounds. These data are compared with the bolometer theory and are used to estimate the expected sensitivity of such a detector used for low background space astronomy. The results demonstrate that the sensitivity and speed of response requirements of the bolometer instruments proposed for these missions can be met by 100 mK spider-web bolometers using neutron transmutation doped germanium as the temperature sensitive element.

Characterization of a Gene Coding for the Complement System Component FB from Loxosceles laeta Spider Venom Glands.

PubMed

Myamoto, Daniela Tiemi; Pidde-Queiroz, Giselle; Gonçalves-de-Andrade, Rute Maria; Pedroso, Aurélio; van den Berg, Carmen W; Tambourgi, Denise V

2016-01-01

The human complement system is composed of more than 30 proteins and many of these have conserved domains that allow tracing the phylogenetic evolution. The complement system seems to be initiated with the appearance of C3 and factor B (FB), the only components found in some protostomes and cnidarians, suggesting that the alternative pathway is the most ancient. Here, we present the characterization of an arachnid homologue of the human complement component FB from the spider Loxosceles laeta. This homologue, named Lox-FB, was identified from a total RNA L. laeta spider venom gland library and was amplified using RACE-PCR techniques and specific primers. Analysis of the deduced amino acid sequence and the domain structure showed significant similarity to the vertebrate and invertebrate FB/C2 family proteins. Lox-FB has a classical domain organization composed of a control complement protein domain (CCP), a von Willebrand Factor domain (vWFA), and a serine protease domain (SP). The amino acids involved in Mg2+ metal ion dependent adhesion site (MIDAS) found in the vWFA domain in the vertebrate C2/FB proteins are well conserved; however, the classic catalytic triad present in the serine protease domain is not conserved in Lox-FB. Similarity and phylogenetic analyses indicated that Lox-FB shares a major identity (43%) and has a close evolutionary relationship with the third isoform of FB-like protein (FB-3) from the jumping spider Hasarius adansoni belonging to the Family Salcitidae.

Characterization of a Gene Coding for the Complement System Component FB from Loxosceles laeta Spider Venom Glands

PubMed Central

Myamoto, Daniela Tiemi; Pidde-Queiroz, Giselle; Gonçalves-de-Andrade, Rute Maria; Pedroso, Aurélio; van den Berg, Carmen W.; Tambourgi, Denise V.

2016-01-01

The human complement system is composed of more than 30 proteins and many of these have conserved domains that allow tracing the phylogenetic evolution. The complement system seems to be initiated with the appearance of C3 and factor B (FB), the only components found in some protostomes and cnidarians, suggesting that the alternative pathway is the most ancient. Here, we present the characterization of an arachnid homologue of the human complement component FB from the spider Loxosceles laeta. This homologue, named Lox-FB, was identified from a total RNA L. laeta spider venom gland library and was amplified using RACE-PCR techniques and specific primers. Analysis of the deduced amino acid sequence and the domain structure showed significant similarity to the vertebrate and invertebrate FB/C2 family proteins. Lox-FB has a classical domain organization composed of a control complement protein domain (CCP), a von Willebrand Factor domain (vWFA), and a serine protease domain (SP). The amino acids involved in Mg2+ metal ion dependent adhesion site (MIDAS) found in the vWFA domain in the vertebrate C2/FB proteins are well conserved; however, the classic catalytic triad present in the serine protease domain is not conserved in Lox-FB. Similarity and phylogenetic analyses indicated that Lox-FB shares a major identity (43%) and has a close evolutionary relationship with the third isoform of FB-like protein (FB-3) from the jumping spider Hasarius adansoni belonging to the Family Salcitidae. PMID:26771533

Space Spider - A concept for fabrication of large structures

NASA Technical Reports Server (NTRS)

Britton, W. R.; Johnston, J. D.

1978-01-01

The Space Spider concept for the automated fabrication of large space structures involves a specialized machine which roll-forms thin gauge material such as aluminum and develops continuous spiral structures with radial struts to sizes of 600-1,000 feet in diameter by 15 feet deep. This concept allows the machine and raw material to be integrated using the Orbiter capabilities, then boosting the rigid system to geosynchronous equatorial orbit (GEO) without high sensitivity to acceleration forces. As a teleoperator controlled device having repetitive operations, the fabrication process can be monitored and verified from a ground-based station without astronaut involvement in GEO. The resultant structure will be useful as an intermediate size platform or as a structural element to be used with other elements such as the space-fabricated beams or composite nested tubes.

The Middlesex Fells Volcanic Complex: A Revised Tectonic Model based on Geochronology, Geochemistry, and Field Data

NASA Astrophysics Data System (ADS)

Hampton, R.

2017-12-01

The Boston Bay area is composed of several terranes originating on the paleocontinent of Avalonia, an arc terrane that accreted onto the continent of Laurentia during the Devonian. Included in these terranes is the Middlesex Fells Volcanic Complex, a bimodal complex composed of both intrusive and extrusive igneous rocks. Initial studies suggested that this volcanic complex formed during a rift event as the Avalonian continent separated from its parent continent 700-900 Ma. New geochemical and geochronological data and field relationships observed in this study establishes a new tectonic model. U-Pb laser ablation zircon data on four samples from different units within the complex reveal that the complex erupted 600 Ma. ICP-MS geochemical analysis of the metabasalt member of the complex yield a trace element signature enriched in Rb, Pb, and Sr and depleted in Th, indicating a subduction component to the melt and interpreted as an eruption into a back-arc basin. The felsic units similarly have an arc related signature when plotted on trace element spider diagrams and tectonic discrimination diagrams. Combined with the field relationships, including an erosional unconformity, stratigraphic and intrusional relationships and large faults from episodic extension events, this data suggests that the Middlesex Fells Volcanic Complex was erupted as part of the arc-sequence of Avalonia and as part of the formation of a back-arc basin well after Avalonia separated from its parent continent. This model presents a significantly younger eruption scenario for the Middlesex Fells Volcanics than previously hypothesized and may be used to study and compare to other volcanics from Avalon terranes in localities such as Newfoundland and the greater Boston area.

Anthropogenic Enrichment of Heavy Metals in Urban Dust and Possible Corresponding Sources

NASA Astrophysics Data System (ADS)

van Laaten, Neele; Merten, Dirk; Pirrung, Michael

2017-04-01

Atmospheric dust (particulate matter, PM) is regarded as a crucial factor for human health and a major environmental problem in densely populated areas. Due to anthropogenic processes like traffic, waste incineration and industry increased amounts of PM can be detected in those areas. To reduce the amounts detailed knowledge on both the composition of PM and the source contribution in a target area is needed. The latter has, to our knowledge, rarely been regarded in central Europe. Within this study, spider webs from various locations in the city of Jena (Germany), that act as natural trappers of PM, were analyzed for the contents of 27 trace elements using aqua regia digestion followed by ICP-OES and ICP-MS determinations. Aerosol-crust enrichment factors were calculated for selected elements and both a cluster analysis and a factor analysis were executed to identify sources of PM. High values for the enrichment factors clearly show an anthropogenic influence. In addition, the cluster analysis leads to a grouping of the sampling points mainly depending on the kind and volume of traffic at the corresponding locations. Five different possible sources of PM can be found by the factor analysis: Soil erosion (41% of variance), abrasion of rails (16%), tyre and break wear (16%), charcoal combustion (8%) and oil combustion (7%).

[Discussion on diagenesis of Xilingang pluton-constrained by X-ray Fluorescence spectroscopy, plasma mass spectrometry and Raman spectroscopy].

PubMed

Tang, Yu-Kun; Chen, Guo-Neng; Zhang, Ke; Huang, Hai-Hua

2013-05-01

The results on Xilingang pluton, mainly consisting of red beds, granites containing numerous debris of red beds and granites, obtained by X-ray fluorescence spectroscopy, plasma mass spectrometry and Raman spectroscopy show: (1) Xilingang pluton from red beds, granites containing numerous debris of red beds to granites has obvious characteristics of decreasing silicon and alkali content, and rising ignition loss, dark mineral content and oxidation index; (2) Chondrite-normalized REE distribution curves and primitive mantle-normalized spider diagram for trace elements of redbed, granites containing numerous debris of red beds and granites have a good consistency, the distribution characteristics of elements are similar to Nanling transformation-type granite; (3) The value of Raman spectrogram characteristic peak of quartz crystal in Xilingang granite decreased from the center of quartz crystal, and FWHM is steady. According to the above, the authors believe that Xilingang granite formed was related to in-situ melting of red beds and underlying strata and magma consolidation. Volatile components were discharged continuously, and oxidation index decreased gradually in the melting process. In the process of diagenesis, the top of pluton tend to be an ongoing silicon and alkali increase, while TFeO and MgO continue to migrate to bottom, and crystallization environment is a relatively closed and steady system.

A Conceptual Design for a Reliable Optical Bus (ROBUS)

NASA Technical Reports Server (NTRS)

Miner, Paul S.; Malekpour, Mahyar; Torres, Wilfredo

2002-01-01

The Scalable Processor-Independent Design for Electromagnetic Resilience (SPIDER) is a new family of fault-tolerant architectures under development at NASA Langley Research Center (LaRC). The SPIDER is a general-purpose computational platform suitable for use in ultra-reliable embedded control applications. The design scales from a small configuration supporting a single aircraft function to a large distributed configuration capable of supporting several functions simultaneously. SPIDER consists of a collection of simplex processing elements communicating via a Reliable Optical Bus (ROBUS). The ROBUS is an ultra-reliable, time-division multiple access broadcast bus with strictly enforced write access (no babbling idiots) providing basic fault-tolerant services using formally verified fault-tolerance protocols including Interactive Consistency (Byzantine Agreement), Internal Clock Synchronization, and Distributed Diagnosis. The conceptual design of the ROBUS is presented in this paper including requirements, topology, protocols, and the block-level design. Verification activities, including the use of formal methods, are also discussed.

In planta production of ELPylated spidroin-based proteins results in non-cytotoxic biopolymers.

PubMed

Hauptmann, Valeska; Menzel, Matthias; Weichert, Nicola; Reimers, Kerstin; Spohn, Uwe; Conrad, Udo

2015-02-19

Spider silk is a tear-resistant and elastic biopolymer that has outstanding mechanical properties. Additionally, exiguous immunogenicity is anticipated for spider silks. Therefore, spider silk represents a potential ideal biomaterial for medical applications. All known spider silk proteins, so-called spidroins, reveal a composite nature of silk-specific units, allowing the recombinant production of individual and combined segments. In this report, a miniaturized spidroin gene, named VSO1 that contains repetitive motifs of MaSp1 has been synthesized and combined to form multimers of distinct lengths, which were heterologously expressed as elastin-like peptide (ELP) fusion proteins in tobacco. The elastic penetration moduli of layered proteins were analyzed for different spidroin-based biopolymers. Moreover, we present the first immunological analysis of synthetic spidroin-based biopolymers. Characterization of the binding behavior of the sera after immunization by competitive ELISA suggested that the humoral immune response is mainly directed against the fusion partner ELP. In addition, cytocompatibility studies with murine embryonic fibroblasts indicated that recombinant spidroin-based biopolymers, in solution or as coated proteins, are well tolerated. The results show that spidroin-based biopolymers can induce humoral immune responses that are dependent on the fusion partner and the overall protein structure. Furthermore, cytocompatibility assays gave no indication of spidroin-derived cytotoxicity, suggesting that recombinant produced biopolymers composed of spider silk-like repetitive elements are suitable for biomedical applications.

Tetranychus urticae mites do not mount an induced immune response against bacteria

PubMed Central

Santos-Matos, Gonçalo; Wybouw, Nicky; Martins, Nelson E.; Zélé, Flore; Riga, Maria; Leitão, Alexandre B.; Vontas, John; Grbić, Miodrag; Van Leeuwen, Thomas; Magalhães, Sara

2017-01-01

The genome of the spider mite Tetranychus urticae, a herbivore, is missing important elements of the canonical Drosophila immune pathways necessary to fight bacterial infections. However, it is not known whether spider mites can mount an immune response and survive bacterial infection. In other chelicerates, bacterial infection elicits a response mediated by immune effectors leading to the survival of infected organisms. In T. urticae, infection by either Escherichia coli or Bacillus megaterium did not elicit a response as assessed through genome-wide transcriptomic analysis. In line with this, spider mites died within days even upon injection with low doses of bacteria that are non-pathogenic to Drosophila. Moreover, bacterial populations grew exponentially inside the infected spider mites. By contrast, Sancassania berlesei, a litter-dwelling mite, controlled bacterial proliferation and resisted infections with both Gram-negative and Gram-positive bacteria lethal to T. urticae. This differential mortality between mite species was absent when mites were infected with heat-killed bacteria. Also, we found that spider mites harbour in their gut 1000-fold less bacteria than S. berlesei. We show that T. urticae has lost the capacity to mount an induced immune response against bacteria, in contrast to other mites and chelicerates but similarly to the phloem feeding aphid Acyrthosiphon pisum. Hence, our results reinforce the putative evolutionary link between ecological conditions regarding exposure to bacteria and the architecture of the immune response. PMID:28592670

Tetranychus urticae mites do not mount an induced immune response against bacteria.

PubMed

Santos-Matos, Gonçalo; Wybouw, Nicky; Martins, Nelson E; Zélé, Flore; Riga, Maria; Leitão, Alexandre B; Vontas, John; Grbić, Miodrag; Van Leeuwen, Thomas; Magalhães, Sara; Sucena, Élio

2017-06-14

The genome of the spider mite Tetranychus urticae , a herbivore, is missing important elements of the canonical Drosophila immune pathways necessary to fight bacterial infections. However, it is not known whether spider mites can mount an immune response and survive bacterial infection. In other chelicerates, bacterial infection elicits a response mediated by immune effectors leading to the survival of infected organisms. In T. urticae , infection by either Escherichia coli or Bacillus megaterium did not elicit a response as assessed through genome-wide transcriptomic analysis. In line with this, spider mites died within days even upon injection with low doses of bacteria that are non-pathogenic to Drosophila Moreover, bacterial populations grew exponentially inside the infected spider mites. By contrast, Sancassania berlesei , a litter-dwelling mite, controlled bacterial proliferation and resisted infections with both Gram-negative and Gram-positive bacteria lethal to T. urticae This differential mortality between mite species was absent when mites were infected with heat-killed bacteria. Also, we found that spider mites harbour in their gut 1000-fold less bacteria than S. berlesei We show that T. urticae has lost the capacity to mount an induced immune response against bacteria, in contrast to other mites and chelicerates but similarly to the phloem feeding aphid Acyrthosiphon pisum Hence, our results reinforce the putative evolutionary link between ecological conditions regarding exposure to bacteria and the architecture of the immune response. © 2017 The Authors.

Ages and origin of felsic rocks from the Eastern Erenhot ophiolitic complex, southeastern Central Asian Orogenic Belt, Inner Mongolia China

NASA Astrophysics Data System (ADS)

Yang, Jinfu; Zhang, Zhicheng; Chen, Yan; Yu, Haifei; Qian, Xiaoyan

2017-08-01

The Central Asian Orogenic Belt (CAOB) is known for its massive Phanerozoic generation of juvenile crust. The tectonic evolution of the CAOB during the late Paleozoic era is still debated. The Eastern Erenhot ophiolite complex (EOC) has been recognized as one of the numerous late Paleozoic ophiolitic blocks in the southeastern part of the CAOB. Zircon U-Pb dating on rhyolite and plagiogranite from the EOC yielded a tight range of ages from 360 to 348 Ma, indicating that the complex formed in the early Carboniferous. The primitive mantle-normalized spider diagram of rhyolites (εNd(t) values of +6.8 and +7) and basalts almost overlaps. Such rhyolites may have been derived from partial melting of juvenile basaltic rocks during the initial opening of the Erenhot-Hegenshan oceanic basin. All of the plagiogranites exhibit similar trace element behaviours of High Field-Strength Elements, such as U, Zr and Hf, and Large Ion Lithophile Elements, such as Ba and Rb, to these of gabbros. These plagiogranites were considered products of episodes of partial melting of hydrous gabbros during ocean floor spreading. We conclude that the northern subduction of the Paleo-Asian Ocean stopped before 360 Ma and the southeastern CAOB experienced extension during the late Paleozoic era. The Erenhot-Hegenshan Ocean, which is comparable to the present Red Sea, originated from syn-collisional crustal thickening, subsequent lithosphere extension, and upwelling of the asthenosphere during orogenic quiescence with an age of 20 Ma.

An Analysis of Factors Affecting Genotyping Success from Museum Specimens Reveals an Increase of Genetic and Morphological Variation during a Historical Range Expansion of a European Spider

PubMed Central

Krehenwinkel, Henrik; Pekar, Stano

2015-01-01

Natural history collections house an enormous amount of plant and animal specimens, which constitute a promising source for molecular analyses. Storage conditions differ among taxa and can have a dramatic effect on the success of DNA work. Here, we analyze the feasibility of DNA extraction from ethanol preserved spiders (Araneae). We tested genotyping success using several hundred specimens of the wasp spider, Argiope bruennichi, deposited in two large German natural history collections. We tested the influence of different factors on the utility of specimens for genotyping. Our results show that not the specimen’s age, but the museum collection is a major predictor of genotyping success. These results indicate that long term storage conditions should be optimized in natural history museums to assure the utility of collections for DNA work. Using historical material, we also traced historical genetic and morphological variation in the course of a poleward range expansion of A. bruennichi by comparing contemporary and historical specimens from a native and an invasive population in Germany. We show that the invasion of A. bruennichi is tightly correlated with an historical increase of genetic and phenotypic variation in the invasive population. PMID:26309219

An Analysis of Factors Affecting Genotyping Success from Museum Specimens Reveals an Increase of Genetic and Morphological Variation during a Historical Range Expansion of a European Spider.

PubMed

Krehenwinkel, Henrik; Pekar, Stano

2015-01-01

Natural history collections house an enormous amount of plant and animal specimens, which constitute a promising source for molecular analyses. Storage conditions differ among taxa and can have a dramatic effect on the success of DNA work. Here, we analyze the feasibility of DNA extraction from ethanol preserved spiders (Araneae). We tested genotyping success using several hundred specimens of the wasp spider, Argiope bruennichi, deposited in two large German natural history collections. We tested the influence of different factors on the utility of specimens for genotyping. Our results show that not the specimen's age, but the museum collection is a major predictor of genotyping success. These results indicate that long term storage conditions should be optimized in natural history museums to assure the utility of collections for DNA work. Using historical material, we also traced historical genetic and morphological variation in the course of a poleward range expansion of A. bruennichi by comparing contemporary and historical specimens from a native and an invasive population in Germany. We show that the invasion of A. bruennichi is tightly correlated with an historical increase of genetic and phenotypic variation in the invasive population.

Trace element distribution in waters of the northern catchment area of Lake Linneret, northern Israel

NASA Astrophysics Data System (ADS)

Sandler, A.; Brenner, I. B.; Halicz, L.

1988-02-01

Waters of the northern watershed of Lake Kineret, sampled during the period 1978 1983, were analyzed for their major and trace element contents. The trace element concentrations of the major water sources of the watershed (the Dan and Banias springs) represent background values. After emergence, the waters are subjected to human activity. In crossing the populated and cultivated Hula Basin in man-made canals, the major and trace element contents increase. In comparison to the trace element concentrations, those of the major elements have narrow ranges and small temporal fluctuations. Trace element concentrations varied by 3 orders of magnitude, and temporal variations were large but not neccessarily seasonal. Point sources of trace elements were urban effluents, fish pond wastes, and peat soil drainage. The trace element concentrations decrease in the waters of the last segment of the Jordan River. All measured trace elements were below the criteria levels established by regulatory agencies. Several, however, were of the same order of magnitude. Addition of wastes from enhanced recycling, and morphologic modification of the final course of the Jordan River could result in increase in the trace element concentrations in the water.

[Analysis of X-ray fluorescence spectroscopy and plasma mass spectrometry of the Guidong granite body and its implications to granite evolution].

PubMed

Li, Hong-Wei; Chen, Guo-Neng; Peng, Zhuo-Lun

2013-07-01

The Guidong composite granite body (CGB) located in the north Guangdong Province consists of numerous rock bodies formed respectively in the early and late Jurassic and early Cretaceous. Analysis of the granites of different period with X-ray fluorescence spectroscopy and plasma mass spectrometry indicates: (1) From the top of a granite body downwards, the felsic components of rock decrease, while the mafic and sigmaREE, LREE/HREE, (La/Yb)N, as well as delta Eu value increase, suggesting the material differentiation in the in-situ melting of crustal rocks and crystallisation of magma; (2) From old to young of the different period granite-massifs in the Guidong CGB, the felsic compositions totally decrease, and the mafic components, sigmaEE, LREE/HREE, (La/Yb)N, and delta Eu value increase as well, implying multiple crustal melting (remelting) events in the Mesozoic in this area; and (3) Primitive mantle-normalized spider diagram for trace elements of Guidong CGB suggests high maturity of the crust involved in the in-situ melting.

Numerical simulation of trace element transport on subsurface environment pollution in coal mine spoil.

PubMed

Qiang, Xue; Bing, Liang; Hui-yun, Wang; Lei, Liu

2006-01-01

An understanding of the dynamic behavior of trace elements leaching from coal mine spoil is important in predicting the groundwater quality. The relationship between trace element concentrations and leaching times, pH values of the media is studied. Column leaching tests conducted in the laboratory showed that there was a close correlation between pH value and trace element concentrations. The longer the leaching time, the higher the trace element concentrations. Different trace elements are differently affected by pH values of leaching media. A numerical model for water flow and trace element transport has been developed based on analyzing the characteristics of migration and transformation of trace elements leached from coal mine spoil. Solutions to the coupled model are accomplished by Eulerian-Lagrangian localized adjoint method. Numerical simulation shows that rainfall intensity determined maximum leaching depth. As rainfall intensity is 3.6ml/s, the outflow concentrations indicate a breakthrough of trace elements beyond the column base, with peak concentration at 90cm depth. And the subsurface pollution range has a trend of increase with time. The model simulations are compared to experimental results of trace element concentrations, with reasonable agreement between them. The analysis and modeling of trace elements suggested that the infiltration of rainwater through the mine spoil might lead to potential groundwater pollution. It provides theoretical evidence for quantitative assessment soil-water quality of trace element transport on environment pollution.

Trace elements in fish from Taihu Lake, China: levels, associated risks, and trophic transfer.

PubMed

Hao, Ying; Chen, Liang; Zhang, Xiaolan; Zhang, Dongping; Zhang, Xinyu; Yu, Yingxin; Fu, Jiamo

2013-04-01

Concentrations of eight trace elements [iron (Fe), manganese (Mn), zinc (Zn), chromium (Cr), mercury (Hg), cadmium (Cd), lead (Pb), and arsenic (As)] were measured in a total of 198 samples covering 24 fish species collected from Taihu Lake, China, in September 2009. The trace elements were detected in all samples, and the total mean concentrations ranged from 18.2 to 215.8 μg/g dw (dry weight). The concentrations of the trace elements followed the sequence of Zn>Fe>Mn>Cr>As>Hg>Pb>Cd. The measured trace element concentrations in fish from Taihu Lake were similar to or lower than the reported values in fish around the world. The metal pollution index was used to compare the total trace element accumulation levels among various species. Toxabramis swinhonis (1.606) accumulated the highest level of the total trace elements, and Saurogobio dabryi (0.315) contained the lowest. The concentrations of human non-essential trace elements (Hg, Cd, Pb, and As) were lower than the allowable maximum levels in fish in China and the European Union. The relationships between the trace element concentrations and the δ(15)N values of fish species were used to investigate the trophic transfer potential of the trace elements. Of the trace elements, Hg might be biomagnified through the food chain in Taihu Lake if the significant level of p-value was set at 0.1. No biomagnification and biodilution were observed for other trace elements. Copyright © 2012 Elsevier Inc. All rights reserved.

Recycling of trace elements required for humans in CELSS.

PubMed

Ashida, A

1994-11-01

Recycle of complete nourishment necessary for human should be constructed in CELSS (Controlled Ecological Life Support Systems). Essential elements necessary for human support are categorized as major elements, semi-major elements and trace elements. Recently, trace elements have been identified from considerations of local diseases, food additive problems, pollution problems and adult diseases, consisting of Fe, Zn, Cu, Se, Co, F, Si, Mn, Cr, I, As, Mo, Ni, V, Sn, Li, Br, Cd, Pb, B. A review of the biogeochemical history of the earth's biosphere and the physiological nature of humans and plants explains some of the requirements. A possible route for intake of trace elements is considered that trace elements are dissolved in some chemical form in water, absorbed by plants through their roots and then transfered to human as foods. There may be a possibility that living things absorb some trace elements from atmosphere. Management and recycling of trace elements in CELSS is discussed.

Recycling of trace elements required for humans in CELSS

NASA Astrophysics Data System (ADS)

Ashida, A.

1994-11-01

Recycle of complete nourishment necessary for human should be constructed in CELSS (Controlled Ecological Life Support Systems). Essential elements necessary for human support are categorized as major elements, semi-major elements and trace elements. Recently, trace elements have been identified from considerations of local diseases, food additive problems, pollution problems and adult diseases, consisting of Fe, Zn, Cu, Se, Co, F, Si, Mn, Cr, I, As, Mo, Ni, V, Sn, Li, Br, Cd, Pb, B. A review of the biogeochemical history of the earth's biosphere and the physiological nature of humans and plants explains some of the requirements. A possible route for intake of trace elements is considered that trace elements are dissolved in some chemical form in water, absorbed by plants through their roots and then transfered to human as foods. There may be a posibility that living things absorb some trace elements from atmosphere. Management and recycling of trace elements in CELSS is discussed.

Trace Elements in River Waters

NASA Astrophysics Data System (ADS)

Gaillardet, J.; Viers, J.; Dupré, B.

2003-12-01

Trace elements are characterized by concentrations lower than 1 mg L-1 in natural waters. This means that trace elements are not considered when "total dissolved solids" are calculated in rivers, lakes, or groundwaters, because their combined mass is not significant compared to the sum of Na+, K+, Ca2+, Mg2+, H4SiO4, HCO3-, CO32-, SO42-, Cl-, and NO3-. Therefore, most of the elements, except about ten of them, occur at trace levels in natural waters. Being trace elements in natural waters does not necessarily qualify them as trace elements in rocks. For example, aluminum, iron, and titanium are major elements in rocks, but they occur as trace elements in waters, due to their low mobility at the Earth's surface. Conversely, trace elements in rocks such as chlorine and carbon are major elements in waters.The geochemistry of trace elements in river waters, like that of groundwater and seawater, is receiving increasing attention. This growing interest is clearly triggered by the technical advances made in the determination of concentrations at lower levels in water. In particular, the development of inductively coupled plasma mass spectrometry (ICP-MS) has considerably improved our knowledge of trace-element levels in waters since the early 1990s. ICP-MS provides the capability of determining trace elements having isotopes of interest for geochemical dating or tracing, even where their dissolved concentrations are extremely low.The determination of trace elements in natural waters is motivated by a number of issues. Although rare, trace elements in natural systems can play a major role in hydrosystems. This is particularly evident for toxic elements such as aluminum, whose concentrations are related to the abundance of fish in rivers. Many trace elements have been exploited from natural accumulation sites and used over thousands of years by human activities. Trace elements are therefore highly sensitive indexes of human impact from local to global scale. Pollution impact studies require knowledge of the natural background concentrations and knowledge of pollutant behavior. For example, it is generally accepted that rare earth elements (REEs) in waters behave as good analogues for the actinides, whose natural levels are quite low and rarely measured. Water quality investigations have clearly been a stimulus for measurement of toxic heavy metals in order to understand their behavior in natural systems.From a more fundamental point of view, it is crucial to understand the behavior of trace elements in geological processes, in particular during chemical weathering and transport by waters. Trace elements are much more fractionated by weathering and transport processes than major elements, and these fractionations give clues for understanding the nature and intensity of the weathering+transport processes. This has not only applications for weathering studies or for the past mobilization and transport of elements to the ocean (potentially recorded in the sediments), but also for the possibility of better utilization of trace elements in the aqueous environment as an exploration tool.In this chapter, we have tried to review the recent literature on trace elements in rivers, in particular by incorporating the results derived from recent ICP-MS measurements. We have favored a "field approach" by focusing on studies of natural hydrosystems. The basic questions which we want to address are the following: What are the trace element levels in river waters? What controls their abundance in rivers and fractionation in the weathering+transport system? Are trace elements, like major elements in rivers, essentially controlled by source-rock abundances? What do we know about the chemical speciation of trace elements in water? To what extent do colloids and interaction with solids regulate processes of trace elements in river waters? Can we relate the geochemistry of trace elements in aquatic systems to the periodic table? And finally, are we able to satisfactorily model and predict the behavior of most of the trace elements in hydrosystems?An impressive literature has dealt with experimental works on aqueous complexation, uptake of trace elements by surface complexation (inorganic and organic), uptake by living organisms (bioaccumulation) that we have not reported here, except when the results of such studies directly explain natural data. As continental waters encompass a greater range of physical and chemical conditions, we focus on river waters and do not discuss trace elements in groundwaters, lakes, and the ocean. In lakes and in the ocean, the great importance of life processes in regulating trace elements is probably the major difference from rivers.Section 5.09.2 of this chapter reports data. We will review the present-day literature on trace elements in rivers to show that our knowledge is still poor. By comparing with the continental abundances, a global mobility index is calculated for each trace element. The spatial and temporal variability of trace-element concentrations in rivers will be shown to be important. In Section 5.09.3, sources of trace elements in river waters are indicated. We will point out the great diversity of sources and the importance of global anthropogenic contamination for a number of elements. The question of inorganic and organic speciation of trace elements in river water will then be addressed in Section 5.09.4, considering some general relationships between speciation and placement in the periodic table. In Section 5.09.5, we will show that studies on organic-rich rivers have led to an exploration of the "colloidal world" in rivers. Colloids are small particles, passing through the conventional filters used to separate dissolved and suspended loads in rivers. They appear as major carriers of trace elements in rivers and considerably complicate aqueous-speciation calculation. Finally, in Section 5.09.6, the significance of interactions between solutes and solid surfaces in river waters will be reviewed. Regulation by surfaces is of major importance for a great range of elements. Although for both colloids and surface interactions, some progress has been made, we are still far from a unified model that can accurately predict trace-element concentrations in natural water systems. This is mainly due to our poor physical description of natural colloids, surface site complexation, and their interaction with solutes.

The role of the seagrass Posidonia oceanica in the cycling of trace elements

NASA Astrophysics Data System (ADS)

Sanz-Lázaro, C.; Malea, P.; Apostolaki, E. T.; Kalantzi, I.; Marín, A.; Karakassis, I.

2012-03-01

The aim of this work was to study the role of the seagrass Posidonia oceanica on the cycling of a wide set of trace elements (Ag, As, Ba, Bi, Cd, Co, Cr, Cs, Cu, Fe, Ga, Li, Mn, Ni, Pb, Rb, Sr, Tl, V and Zn). We measured the concentration of these trace elements in the different compartments of P. oceanica (leaves, rhizomes, roots and epibiota) in a non-polluted seagrass meadow representative of the Mediterranean and calculated the annual budget from a mass balance. We provide novel data on accumulation dynamics of many trace elements in P. oceanica compartments and demonstrate that trace element accumulation patterns are mainly determined by plant compartment rather than by temporal variability. Epibiota was the compartment which showed the greatest concentrations for most trace elements. Thus, they constitute a key compartment when estimating trace element transfer to higher trophic levels by P. oceanica. For most trace elements, translocation seemed to be low and acropetal. Zn, Cd, Sr and Rb were the trace elements that showed the highest release rate through decomposition of plant detritus, while Cs, Tl and Bi the lowest. P. oceanica acts as a sink of potentially toxic trace elements (Ni, Cr, As and Ag), which can be sequestered, decreasing their bioavailability. P. oceanica may have a relevant role in the cycling of trace elements in the Mediterranean.

The role of the seagrass Posidonia oceanica in the cycling of trace elements

NASA Astrophysics Data System (ADS)

Sanz-Lázaro, C.; Malea, P.; Apostolaki, E. T.; Kalantzi, I.; Marín, A.; Karakassis, I.

2012-07-01

The aim of this study was to investigate the role of the seagrass Posidonia oceanica on the cycling of a wide set of trace elements (Ag, As, Ba, Bi, Cd, Co, Cr, Cs, Cu, Fe, Ga, Li, Mn, Ni, Pb, Rb, Sr, Tl, V and Zn). We measured the concentration of these trace elements in different compartments of P. oceanica (leaves, rhizomes, roots and epiphytes) in a non-polluted seagrass meadow representative of the Mediterranean and calculated the annual budget from a mass balance. We provide novel data on accumulation dynamics of many trace elements in P. oceanica compartments and demonstrate that trace element accumulation patterns are mainly determined by plant compartment rather than by temporal variability. Epiphytes were the compartment, which showed the greatest concentrations for most trace elements. Thus, they constitute a key compartment when estimating trace element transfer to higher trophic levels by P. oceanica. Trace element translocation in P. oceanica seemed to be low and acropetal in most cases. Zn, Cd, Sr and Rb were the trace elements that showed the highest release rate through decomposition of plant detritus, while Cs, Tl and Bi showed the lowest. P. oceanica acts as a sink of potentially toxic trace elements (Ni, Cr, As and Ag), which can be sequestered, decreasing their bioavailability. P. oceanica may have a relevant role in the cycling of trace elements in the Mediterranean.

Rate-Dependent Behavior of the Amorphous Phase of Spider Dragline Silk

PubMed Central

Patil, Sandeep P.; Markert, Bernd; Gräter, Frauke

2014-01-01

The time-dependent stress-strain behavior of spider dragline silk was already observed decades ago, and has been attributed to the disordered sequences in silk proteins, which compose the soft amorphous matrix. However, the actual molecular origin and magnitude of internal friction within the amorphous matrix has remained inaccessible, because experimentally decomposing the mechanical response of the amorphous matrix from the embedded crystalline units is challenging. Here, we used atomistic molecular dynamics simulations to obtain friction forces for the relative sliding of peptide chains of Araneus diadematus spider silk within bundles of these chains as a representative unit of the amorphous matrix in silk fibers. We computed the friction coefficient and coefficient of viscosity of the amorphous phase to be in the order of 10−6 Ns/m and 104 Ns/m2, respectively, by extrapolating our simulation data to the viscous limit. Finally, we used a finite element method for the amorphous phase, solely based on parameters derived from molecular dynamics simulations including the newly determined coefficient of viscosity. With this model the time scales of stress relaxation, creep, and hysteresis were assessed, and found to be in line with the macroscopic time-dependent response of silk fibers. Our results suggest the amorphous phase to be the primary source of viscosity in silk and open up the avenue for finite element method studies of silk fiber mechanics including viscous effects. PMID:24896131

Trace Elements and Healthcare: A Bioinformatics Perspective.

PubMed

Zhang, Yan

2017-01-01

Biological trace elements are essential for human health. Imbalance in trace element metabolism and homeostasis may play an important role in a variety of diseases and disorders. While the majority of previous researches focused on experimental verification of genes involved in trace element metabolism and those encoding trace element-dependent proteins, bioinformatics study on trace elements is relatively rare and still at the starting stage. This chapter offers an overview of recent progress in bioinformatics analyses of trace element utilization, metabolism, and function, especially comparative genomics of several important metals. The relationship between individual elements and several diseases based on recent large-scale systematic studies such as genome-wide association studies and case-control studies is discussed. Lastly, developments of ionomics and its recent application in human health are also introduced.

Fabrication and Test of Large Area Spider-Web Bolometers for CMB Measurements

NASA Astrophysics Data System (ADS)

Biasotti, M.; Ceriale, V.; Corsini, D.; De Gerone, M.; Gatti, F.; Orlando, A.; Pizzigoni, G.

2016-08-01

Detecting the primordial 'B-mode' polarization of the cosmic microwave background is one of the major challenges of modern observational cosmology. Microwave telescopes need sensitive cryogenic bolometers with an overall equivalent noise temperature in the nK range. In this paper, we present the development status of large area (about 1 cm2) spider-web bolometer, which imply additional fabrication challenges. The spider-web is a suspended Si3N4 1 \\upmu m-thick and 8-mm diameter with mesh size of 250 \\upmu m. The thermal sensitive element is a superconducting transition edge sensor (TES) at the center of the bolometer. The first prototype is a Ti-Au TES with transition temperature tuned around 350 mK, new devices will be a Mo-Au bilayer tuned to have a transition temperature of 500 mK. We present the fabrication process with micro-machining techniques from silicon wafer covered with SiO2 - Si3N4 CVD films, 0.3 and 1 \\upmu m- thick, respectively, and preliminary tests.

Atmospheric transport of trace elements and nutrients to the oceans

PubMed Central

Chance, R.

2016-01-01

This paper reviews atmospheric inputs of trace elements and nutrients to the oceans in the context of the GEOTRACES programme and provides new data from two Atlantic GEOTRACES cruises. We consider the deposition of nitrogen to the oceans, which is now dominated by anthropogenic emissions, the deposition of mineral dust and related trace elements, and the deposition of other trace elements which have a mixture of anthropogenic and dust sources. We then consider the solubility (as a surrogate for bioavailability) of the various elements. We consider briefly the sources, atmospheric transport and transformations of these elements and how this results in strong spatial deposition gradients. Solubility of the trace elements also varies systematically between elements, reflecting their sources and cycling, and for some trace elements there are also systematic gradients in solubility related to dust loading. Together, these effects create strong spatial gradients in the inputs of bioavailable trace elements to the oceans, and we are only just beginning to understand how these affect ocean biogeochemistry. This article is part of the themed issue ‘Biological and climatic impacts of ocean trace element chemistry’. PMID:29035252

The role of plant-associated bacteria in the mobilization and phytoextraction of trace elements in contaminated soils

PubMed Central

Sessitsch, Angela; Kuffner, Melanie; Kidd, Petra; Vangronsveld, Jaco; Wenzel, Walter W.; Fallmann, Katharina; Puschenreiter, Markus

2013-01-01

Phytoextraction makes use of trace element-accumulating plants that concentrate the pollutants in their tissues. Pollutants can be then removed by harvesting plants. The success of phytoextraction depends on trace element availability to the roots and the ability of the plant to intercept, take up, and accumulate trace elements in shoots. Current phytoextraction practises either employ hyperaccumulators or fast-growing high biomass plants; the phytoextraction process may be enhanced by soil amendments that increase trace element availability in the soil. This review will focus on the role of plant-associated bacteria to enhance trace element availability in the rhizosphere. We report on the kind of bacteria typically found in association with trace element – tolerating or – accumulating plants and discuss how they can contribute to improve trace element uptake by plants and thus the efficiency and rate of phytoextraction. This enhanced trace element uptake can be attributed to a microbial modification of the absorptive properties of the roots such as increasing the root length and surface area and numbers of root hairs, or by increasing the plant availability of trace elements in the rhizosphere and the subsequent translocation to shoots via beneficial effects on plant growth, trace element complexation and alleviation of phytotoxicity. An analysis of data from literature shows that effects of bacterial inoculation on phytoextraction efficiency are currently inconsistent. Some key processes in plant–bacteria interactions and colonization by inoculated strains still need to be unravelled more in detail to allow full-scale application of bacteria assisted phytoremediation of trace element contaminated soils. PMID:23645938

The role of plant-associated bacteria in the mobilization and phytoextraction of trace elements in contaminated soils.

PubMed

Sessitsch, Angela; Kuffner, Melanie; Kidd, Petra; Vangronsveld, Jaco; Wenzel, Walter W; Fallmann, Katharina; Puschenreiter, Markus

2013-05-01

Phytoextraction makes use of trace element-accumulating plants that concentrate the pollutants in their tissues. Pollutants can be then removed by harvesting plants. The success of phytoextraction depends on trace element availability to the roots and the ability of the plant to intercept, take up, and accumulate trace elements in shoots. Current phytoextraction practises either employ hyperaccumulators or fast-growing high biomass plants; the phytoextraction process may be enhanced by soil amendments that increase trace element availability in the soil. This review will focus on the role of plant-associated bacteria to enhance trace element availability in the rhizosphere. We report on the kind of bacteria typically found in association with trace element - tolerating or - accumulating plants and discuss how they can contribute to improve trace element uptake by plants and thus the efficiency and rate of phytoextraction. This enhanced trace element uptake can be attributed to a microbial modification of the absorptive properties of the roots such as increasing the root length and surface area and numbers of root hairs, or by increasing the plant availability of trace elements in the rhizosphere and the subsequent translocation to shoots via beneficial effects on plant growth, trace element complexation and alleviation of phytotoxicity. An analysis of data from literature shows that effects of bacterial inoculation on phytoextraction efficiency are currently inconsistent. Some key processes in plant-bacteria interactions and colonization by inoculated strains still need to be unravelled more in detail to allow full-scale application of bacteria assisted phytoremediation of trace element contaminated soils.

Fractional-order Fourier analysis for ultrashort pulse characterization.

PubMed

Brunel, Marc; Coetmellec, Sébastien; Lelek, Mickael; Louradour, Frédéric

2007-06-01

We report what we believe to be the first experimental demonstration of ultrashort pulse characterization using fractional-order Fourier analysis. The analysis is applied to the interpretation of spectral interferometry resolved in time (SPIRIT) traces [which are spectral phase interferometry for direct electric field reconstruction (SPIDER)-like interferograms]. First, the fractional-order Fourier transformation is shown to naturally allow the determination of the cubic spectral phase coefficient of pulses to be analyzed. A simultaneous determination of both cubic and quadratic spectral phase coefficients of the pulses using the fractional-order Fourier series expansion is further demonstrated. This latter technique consists of localizing relative maxima in a 2D cartography representing decomposition coefficients. It is further used to reconstruct or filter SPIRIT traces.

siRNAs and piRNAs Collaborate for Transposon Control in the Two-Spotted Spider Mite.

PubMed

Mondal, Mosharrof; Mansfield, Kody; Flynt, Alex

2018-04-20

RNAi has revolutionized genetic research, and is being commercialized as an insect pest control technology. Mechanisms exploited for this purpose are antiviral and therefore rapidly evolving. Ideally, RNAi will also be used for non-insect pests, however, differences in RNAi biology makes this uncertain. Tetranychus urticae (two-spotted spider mite) is a destructive non-insect pest, which has a proclivity to develop pesticide resistance. Here we provide a comprehensive study of the endogenous RNAi pathways of spider mites to inform design of exogenous RNAi triggers. This effort revealed unexpected roles for small RNAs and novel genome surveillance pathways. Spider mites have an expanded RNAi machinery relative to insects, encoding RNA dependent RNA polymerase (Rdrp) and extra Piwi-class effectors. Through analyzing T. urticae transcriptome data we explored small RNA biogenesis, and discovered five siRNA loci that appear central to genome surveillance. These RNAs are expressed in the gonad, which we hypothesize to trigger production of piRNAs for control of transposable elements (TEs). This work highlights the need to investigate endogenous RNAi biology as lessons from model organisms may not hold in other species, impacting development of an RNAi strategy. Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Jewelled spiders manipulate colour-lure geometry to deceive prey

PubMed Central

2017-01-01

Selection is expected to favour the evolution of efficacy in visual communication. This extends to deceptive systems, and predicts functional links between the structure of visual signals and their behavioural presentation. Work to date has primarily focused on colour, however, thereby understating the multicomponent nature of visual signals. Here I examined the relationship between signal structure, presentation behaviour, and efficacy in the context of colour-based prey luring. I used the polymorphic orb-web spider Gasteracantha fornicata, whose yellow- or white-and-black striped dorsal colours have been broadly implicated in prey attraction. In a manipulative assay, I found that spiders actively control the orientation of their conspicuous banded signals in the web, with a distinct preference for near-diagonal bearings. Further field-based study identified a predictive relationship between pattern orientation and prey interception rates, with a local maximum at the spiders' preferred orientation. There were no morph-specific effects on capture success, either singularly or via an interaction with pattern orientation. These results reveal a dynamic element in a traditionally ‘static’ signalling context, and imply differential functions for chromatic and geometric signal components across visual contexts. More broadly, they underscore how multicomponent signal designs and display behaviours may coevolve to enhance efficacy in visual deception. PMID:28356411

Jewelled spiders manipulate colour-lure geometry to deceive prey.

PubMed

White, Thomas E

2017-03-01

Selection is expected to favour the evolution of efficacy in visual communication. This extends to deceptive systems, and predicts functional links between the structure of visual signals and their behavioural presentation. Work to date has primarily focused on colour, however, thereby understating the multicomponent nature of visual signals. Here I examined the relationship between signal structure, presentation behaviour, and efficacy in the context of colour-based prey luring. I used the polymorphic orb-web spider Gasteracantha fornicata , whose yellow- or white-and-black striped dorsal colours have been broadly implicated in prey attraction. In a manipulative assay, I found that spiders actively control the orientation of their conspicuous banded signals in the web, with a distinct preference for near-diagonal bearings. Further field-based study identified a predictive relationship between pattern orientation and prey interception rates, with a local maximum at the spiders' preferred orientation. There were no morph-specific effects on capture success, either singularly or via an interaction with pattern orientation. These results reveal a dynamic element in a traditionally 'static' signalling context, and imply differential functions for chromatic and geometric signal components across visual contexts. More broadly, they underscore how multicomponent signal designs and display behaviours may coevolve to enhance efficacy in visual deception. © 2017 The Author(s).

Trace Elements and Carbon and Nitrogen Stable Isotopes in Organisms from a Tropical Coastal Lagoon

PubMed Central

van Hattum, B.; de Boer, J.; van Bodegom, P. M.; Rezende, C. E.; Salomons, W.

2010-01-01

Trace elements (Fe, Mn, Al, Zn, Cr, Cu, Ni, Pb, Cd, Hg, and As) and stable isotope ratios (δ13C and δ15N) were analyzed in sediments, invertebrates, and fishes from a tropical coastal lagoon influenced by iron ore mining and processing activities to assess the differences in trace element accumulation patterns among species and to investigate relations with trophic levels of the organisms involved. Overall significant negative relations between trophic level (given by 15N) and trace element concentrations in gastropods and crustaceans showed differences in internal controls of trace element accumulation among the species of different trophic positions, leading to trace element dilution. Generally, no significant relation between δ15N and trace element concentrations was observed among fish species, probably due to omnivory in a number of species as well as fast growth. Trace element accumulation was observed in the fish tissues, with higher levels of most trace elements found in liver compared with muscle and gill. Levels of Fe, Mn, Al, and Hg in invertebrates, and Fe and Cu in fish livers, were comparable with levels in organisms and tissues from other contaminated areas. Trace element levels in fish muscle were below the international safety baseline standards for human consumption. PMID:20217062

Trace elements and carbon and nitrogen stable isotopes in organisms from a tropical coastal lagoon.

PubMed

Pereira, A A; van Hattum, B; de Boer, J; van Bodegom, P M; Rezende, C E; Salomons, W

2010-10-01

Trace elements (Fe, Mn, Al, Zn, Cr, Cu, Ni, Pb, Cd, Hg, and As) and stable isotope ratios (delta(13)C and delta(15)N) were analyzed in sediments, invertebrates, and fishes from a tropical coastal lagoon influenced by iron ore mining and processing activities to assess the differences in trace element accumulation patterns among species and to investigate relations with trophic levels of the organisms involved. Overall significant negative relations between trophic level (given by (15)N) and trace element concentrations in gastropods and crustaceans showed differences in internal controls of trace element accumulation among the species of different trophic positions, leading to trace element dilution. Generally, no significant relation between delta(15)N and trace element concentrations was observed among fish species, probably due to omnivory in a number of species as well as fast growth. Trace element accumulation was observed in the fish tissues, with higher levels of most trace elements found in liver compared with muscle and gill. Levels of Fe, Mn, Al, and Hg in invertebrates, and Fe and Cu in fish livers, were comparable with levels in organisms and tissues from other contaminated areas. Trace element levels in fish muscle were below the international safety baseline standards for human consumption.

Surface-water-quality assessment of the Yakima River basin in Washington; spatial and temporal distribution of trace elements in water, sediment, and aquatic biota, 1987-91; with a section on geology

USGS Publications Warehouse

Fuhrer, Gregory J.; Cain, Daniel J.; McKenzie, Stuart W.; Rinella, Joseph F.; Crawford, J. Kent; Skach, Kenneth A.; Hornberger, Michelle I.; Gannett, Marshall W.

1999-01-01

The report describes the distribution of trace elements in sediment, water, and aquatic biota in the Yakima River basin, Washington. Trace elements were determined from streambed sediment, suspended sediment, filtered and unfiltered water samples, aquatic insects, clams, fish livers, and fish fillets between 1987 and 1991. The distribution of trace elements in these media was related to local geology and anthropogenic sources. Additionally, annual and instantaneous loads were estimated for trace elements associated with suspended sediment and trace elements in filtered water samples. Trace elements also were screened against U.S. Environmental Protection Agency guidelines established for the protection of human health and aquatic life.

A new perspective of using sequential extraction: To predict the deficiency of trace elements during anaerobic digestion.

PubMed

Cai, Yafan; Wang, Jungang; Zhao, Yubin; Zhao, Xiaoling; Zheng, Zehui; Wen, Boting; Cui, Zongjun; Wang, Xiaofen

2018-09-01

Trace elements were commonly used as additives to facilitate anaerobic digestion. However, their addition is often blind because of the complexity of reaction conditions, which has impeded their widespread application. Therefore, this study was conducted to evaluate deficiencies in trace elements during anaerobic digestion by establishing relationships between changes in trace element bioavailability (the degree to which elements are available for interaction with biological systems) and digestion performance. To accomplish this, two batch experiments were conducted. In the first, sequential extraction was used to detect changes in trace element fractions and then to evaluate trace element bioavailability in the whole digestion cycle. In the second batch experiment, trace elements (Co, Fe, Cu, Zn, Mn, Mo and Se) were added to the reaction system at three concentrations (low, medium and high) and their effects were monitored. The results showed that sequential extraction was a suitable method for assessment of the bioavailability of trace elements (appropriate coefficient of variation and recovery rate). The results revealed that Se had the highest (44.2%-70.9%) bioavailability, while Fe had the lowest (1.7%-3.0%). A lack of trace elements was not directly related to their absolute bioavailability, but was instead associated with changes in their bioavailability throughout the digestion cycle. Trace elements were insufficient when their bioavailability was steady or increased over the digestion cycle. These results indicate that changes in trace element bioavailability during the digestion cycle can be used to predict their deficiency. Copyright © 2018 Elsevier Ltd. All rights reserved.

Trace element profiles of the sea anemone Anemonia viridis living nearby a natural CO2 vent

PubMed Central

Borell, Esther M.; Fine, Maoz; Shaked, Yeala

2014-01-01

Ocean acidification (OA) is not an isolated threat, but acts in concert with other impacts on ecosystems and species. Coastal marine invertebrates will have to face the synergistic interactions of OA with other global and local stressors. One local factor, common in coastal environments, is trace element contamination. CO2 vent sites are extensively studied in the context of OA and are often considered analogous to the oceans in the next few decades. The CO2 vent found at Levante Bay (Vulcano, NE Sicily, Italy) also releases high concentrations of trace elements to its surrounding seawater, and is therefore a unique site to examine the effects of long-term exposure of nearby organisms to high pCO2 and trace element enrichment in situ. The sea anemone Anemonia viridis is prevalent next to the Vulcano vent and does not show signs of trace element poisoning/stress. The aim of our study was to compare A. viridis trace element profiles and compartmentalization between high pCO2 and control environments. Rather than examining whole anemone tissue, we analyzed two different body compartments—the pedal disc and the tentacles, and also examined the distribution of trace elements in the tentacles between the animal and the symbiotic algae. We found dramatic changes in trace element tissue concentrations between the high pCO2/high trace element and control sites, with strong accumulation of iron, lead, copper and cobalt, but decreased concentrations of cadmium, zinc and arsenic proximate to the vent. The pedal disc contained substantially more trace elements than the anemone’s tentacles, suggesting the pedal disc may serve as a detoxification/storage site for excess trace elements. Within the tentacles, the various trace elements displayed different partitioning patterns between animal tissue and algal symbionts. At both sites iron was found primarily in the algae, whereas cadmium, zinc and arsenic were primarily found in the animal tissue. Our data suggests that A. viridis regulates its internal trace element concentrations by compartmentalization and excretion and that these features contribute to its resilience and potential success at the trace element-rich high pCO2 vent. PMID:25250210

Trace elements as quantitative probes of differentiation processes in planetary interiors

NASA Technical Reports Server (NTRS)

Drake, M. J.

1980-01-01

The characteristic trace element signature that each mineral in the source region imparts on the magma constitutes the conceptual basis for trace element modeling. It is shown that abundances of trace elements in extrusive igneous rocks may be used as petrological and geochemical probes of the source regions of the rocks if differentiation processes, partition coefficients, phase equilibria, and initial concentrations in the source region are known. Although compatible and incompatible trace elements are useful in modeling, the present review focuses primarily on examples involving the rare-earth elements.

Parenteral trace element provision: recent clinical research and practical conclusions

PubMed Central

Stehle, P; Stoffel-Wagner, B; Kuhn, K S

2016-01-01

The aim of this systematic review (PubMed, www.ncbi.nlm.nih.gov/pubmed and Cochrane, www.cochrane.org; last entry 31 December 2014) was to present data from recent clinical studies investigating parenteral trace element provision in adult patients and to draw conclusions for clinical practice. Important physiological functions in human metabolism are known for nine trace elements: selenium, zinc, copper, manganese, chromium, iron, molybdenum, iodine and fluoride. Lack of, or an insufficient supply of, these trace elements in nutrition therapy over a prolonged period is associated with trace element deprivation, which may lead to a deterioration of existing clinical symptoms and/or the development of characteristic malnutrition syndromes. Therefore, all parenteral nutrition prescriptions should include a daily dose of trace elements. To avoid trace element deprivation or imbalances, physiological doses are recommended. PMID:27049031

Trace Elements Characteristic Based on ICP-AES and the Correlation of Flavonoids from Sparganii rhizoma.

PubMed

Wang, Xinsheng; Wu, Yanfang; Wu, Chengying; Wu, Qinan; Niu, Qingshan

2018-04-01

The aim of the present work was to investigate the trace elements and the correlation with flavonoids from Sparganii rhizoma. The ICP-AES and ultraviolet-visible spectroscopy were employed to analyze trace elements and flavonoids. The concentrations of trace elements and flavonoids were calculated using standard curve. The content of flavonoids was expressed as rutin equivalents. The cluster analysis was applied to evaluate geographical features of S. rhizoma from different geographical regions. The correlation analysis was used to obtain the relationship between the trace elements and flavonoids. The results indicated that the 15 trace elements were measured and the K, Ca, Mg, Na, Mn, Al, Cu, and Zn are rich in Sparganii rhizome. The different producing regions samples were classified into four groups. There was a weak relationship between trace elements and flavonoids.

3-D Modeling of Planar Target-Mount Perturbation Experiments on OMEGA

NASA Astrophysics Data System (ADS)

Collins, T. J. B.; Marshall, F. J.; Marozas, J. A.; Bonino, M. J.; Forties, R.; Goncharov, V. N.; Igumenshchev, I. V.; McKenty, P. W.; Smalyuk, V. A.

2008-11-01

OMEGA cryogenic targets are suspended in the target chamber using four spider silks attached to a C-shaped mount. The spider silks are typically composed of two entwined protein strands comparable to 1 μm in diameter. The silks and mount refract the incident laser light and cast shadows on the target surface. Experiments to measure the effects of the silks on target illumination have been performed in planar geometry using silks suspended parallel to a 20-μm-thick laser-driven target. The evolution of the surface perturbations introduced by the silks was measured using x-ray backlighting. The results of these experiments will be compared to simulations performed with DRACO, employing three-dimensional (3-D) planar hydrodynamics and a new 3-D refractive ray-trace package written specifically for this geometry. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.

Trace Elements in Ovaries: Measurement and Physiology.

PubMed

Ceko, Melanie J; O'Leary, Sean; Harris, Hugh H; Hummitzsch, Katja; Rodgers, Raymond J

2016-04-01

Traditionally, research in the field of trace element biology and human and animal health has largely depended on epidemiological methods to demonstrate involvement in biological processes. These studies were typically followed by trace element supplementation trials or attempts at identification of the biochemical pathways involved. With the discovery of biological molecules that contain the trace elements, such as matrix metalloproteinases containing zinc (Zn), cytochrome P450 enzymes containing iron (Fe), and selenoproteins containing selenium (Se), much of the current research focuses on these molecules, and, hence, only indirectly on trace elements themselves. This review focuses largely on two synchrotron-based x-ray techniques: X-ray absorption spectroscopy and x-ray fluorescence imaging that can be used to identify the in situ speciation and distribution of trace elements in tissues, using our recent studies of bovine ovaries, where the distribution of Fe, Se, Zn, and bromine were determined. It also discusses the value of other techniques, such as inductively coupled plasma mass spectrometry, used to garner information about the concentrations and elemental state of the trace elements. These applications to measure trace elemental distributions in bovine ovaries at high resolutions provide new insights into possible roles for trace elements in the ovary. © 2016 by the Society for the Study of Reproduction, Inc.

A study of the impact of moist-heat and dry-heat treatment processes on hazardous trace elements migration in food waste.

PubMed

Chen, Ting; Jin, Yiying; Qiu, Xiaopeng; Chen, Xin

2015-03-01

Using laboratory experiments, the authors investigated the impact of dry-heat and moist-heat treatment processes on hazardous trace elements (As, Hg, Cd, Cr, and Pb) in food waste and explored their distribution patterns for three waste components: oil, aqueous, and solid components. The results indicated that an insignificant reduction of hazardous trace elements in heat-treated waste-0.61-14.29% after moist-heat treatment and 4.53-12.25% after dry-heat treatment-and a significant reduction in hazardous trace elements (except for Hg without external addition) after centrifugal dehydration (P < 0.5). Moreover, after heat treatment, over 90% of the hazardous trace elements in the waste were detected in the aqueous and solid components, whereas only a trace amount of hazardous trace elements was detected in the oil component (<0.01%). In addition, results indicated that heat treatment process did not significantly reduce the concentration of hazardous trace elements in food waste, but the separation process for solid and aqueous components, such as centrifugal dehydration, could reduce the risk considerably. Finally, combined with the separation technology for solid and liquid components, dry-heat treatment is superior to moist-heat treatment on the removal of external water-soluble ionic hazardous trace elements. An insignificant reduction of hazardous trace elements in heat-treated waste showed that heat treatment does not reduce trace elements contamination in food waste considerably, whereas the separation process for solid and aqueous components, such as centrifugal dehydration, could reduce the risk significantly. Moreover, combined with the separation technology for solid and liquid components, dry-heat treatment is superior to moist-heat treatment for the removal of external water-soluble ionic hazardous trace elements, by exploring distribution patterns of trace elements in three waste components: oil, aqueous, and solid components.

Corticosterone levels in relation to trace element contamination along an urbanization gradient in the common blackbird (Turdus merula).

PubMed

Meillère, Alizée; Brischoux, François; Bustamante, Paco; Michaud, Bruno; Parenteau, Charline; Marciau, Coline; Angelier, Frédéric

2016-10-01

In a rapidly urbanizing world, trace element pollution may represent a threat to human health and wildlife, and it is therefore crucial to assess both exposition levels and associated effects of trace element contamination on urban vertebrates. In this study, we investigated the impact of urbanization on trace element contamination and stress physiology in a wild bird species, the common blackbird (Turdus merula), along an urbanization gradient (from rural to moderately urbanized areas). Specifically, we described the contamination levels of blackbirds by 4 non-essential (Ag, Cd, Hg, Pb) and 9 essential trace elements (As, Co, Cr, Cu, Fe, Mn, Ni, Se, Zn), and explored the putative disrupting effects of the non-essential element contamination on corticosterone levels (a hormonal proxy for environmental challenges). We found that non-essential trace element burden (Cd and Pb specifically) increased with increasing urbanization, indicating a significant trace element contamination even in medium sized cities and suburban areas. Interestingly, the increased feather non-essential trace element concentrations were also associated with elevated feather corticosterone levels, suggesting that urbanization probably constrains birds and that this effect may be mediated by trace element contamination. Future experimental studies are now required to disentangle the influence of multiple urban-related constraints on corticosterone levels and to specifically test the influence of each of these trace elements on corticosterone secretion. Copyright © 2016 Elsevier B.V. All rights reserved.

Identification of "Known Unknowns" Utilizing Accurate Mass Data and ChemSpider

NASA Astrophysics Data System (ADS)

Little, James L.; Williams, Antony J.; Pshenichnov, Alexey; Tkachenko, Valery

2012-01-01

In many cases, an unknown to an investigator is actually known in the chemical literature, a reference database, or an internet resource. We refer to these types of compounds as "known unknowns." ChemSpider is a very valuable internet database of known compounds useful in the identification of these types of compounds in commercial, environmental, forensic, and natural product samples. The database contains over 26 million entries from hundreds of data sources and is provided as a free resource to the community. Accurate mass mass spectrometry data is used to query the database by either elemental composition or a monoisotopic mass. Searching by elemental composition is the preferred approach. However, it is often difficult to determine a unique elemental composition for compounds with molecular weights greater than 600 Da. In these cases, searching by the monoisotopic mass is advantageous. In either case, the search results are refined by sorting the number of references associated with each compound in descending order. This raises the most useful candidates to the top of the list for further evaluation. These approaches were shown to be successful in identifying "known unknowns" noted in our laboratory and for compounds of interest to others.

A Method for Assessing the Retention of Trace Elements in Human Body Using Neural Network Technology

PubMed Central

Ragimov, Aligejdar; Faizullin, Rashat; Valiev, Vsevolod

2017-01-01

Models that describe the trace element status formation in the human organism are essential for a correction of micromineral (trace elements) deficiency. A direct trace element retention assessment in the body is difficult due to the many internal mechanisms. The trace element retention is determined by the amount and the ratio of incoming and excreted substance. So, the concentration of trace elements in drinking water characterizes the intake, whereas the element concentration in urine characterizes the excretion. This system can be interpreted as three interrelated elements that are in equilibrium. Since many relationships in the system are not known, the use of standard mathematical models is difficult. The artificial neural network use is suitable for constructing a model in the best way because it can take into account all dependencies in the system implicitly and process inaccurate and incomplete data. We created several neural network models to describe the retentions of trace elements in the human body. On the model basis, we can calculate the microelement levels in the body, knowing the trace element levels in drinking water and urine. These results can be used in health care to provide the population with safe drinking water. PMID:29065586

Assessment of trace element impacts on agricultural use of water from the Dan River following the Eden coal ash release.

PubMed

Hesterberg, Dean; Polizzotto, Matthew L; Crozier, Carl; Austin, Robert E

2016-04-01

Catastrophic events require rapid, scientifically sound decision making to mitigate impacts on human welfare and the environment. The objective of this study was to analyze potential impacts of coal ash-derived trace elements on agriculture following a 35,000-tonne release of coal ash into the Dan River at the Duke Energy Steam Station in Eden, North Carolina. We performed scenario calculations to assess the potential for excessive trace element loading to soils via irrigation and flooding with Dan River water, uptake of trace elements by crops, and livestock consumption of trace elements via drinking water. Concentrations of 13 trace elements measured in Dan River water samples within 4 km of the release site declined sharply after the release and were equivalent within 5 d to measurements taken upriver. Mass-balance calculations based on estimates of soil trace-element concentrations and the nominal river water concentrations indicated that irrigation or flooding with 25 cm of Dan River water would increase soil concentrations of all trace elements by less than 0.5%. Calculations of potential increases of trace elements in corn grain and silage, fescue, and tobacco leaves suggested that As, Cr, Se, Sr, and V were elements of most concern. Concentrations of trace elements measured in river water following the ash release never exceeded adopted standards for livestock drinking water. Based on our analyses, we present guidelines for safe usage of Dan River water to diminish negative impacts of trace elements on soils and crop production. In general, the approach we describe here may serve as a basis for rapid assessment of environmental and agricultural risks associated with any similar types of releases that arise in the future. © 2015 SETAC.

New Perspectives on the Essential Trace Elements.

ERIC Educational Resources Information Center

Frieden, Earl

1985-01-01

Provides a comprehensive overview of the 19 essential trace elements, examining: the concept of essentiality; evolution of these elements; possible future essential elements; the lanthanides and actinides; how essential trace elements work; the metalloenzymes; the nonmetals; iodine and the thyroid hormones; and antagonism among these elements. (JN)

Trace element contaminants in mineral fertilizers used in Iran.

PubMed

Latifi, Zahra; Jalali, Mohsen

2018-05-25

The application of mineral fertilizers which have contaminants of trace elements may impose concern regarding the entry and toxic accumulation of these elements in agro-ecosystems. In this study, 57 mineral fertilizers (nitrogen, potassium, phosphate, and compound fertilizers) distributed in Iran were analyzed for their contents of Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Fe. The results revealed that the contents of these trace elements varied considerably depending on the type of the element and the fertilizer. Among these elements, Fe displayed the highest average content, whereas Cd showed the lowest. Generally, the trace element contents in P-containing fertilizers were higher than those in nitrogen and potassium fertilizers. The mean values of trace elements (mg kg -1 ) in P-containing fertilizers were 4.0 (Cd), 5.5 (Co), 35.7 (Cr), 24.4 (Cu), 272 (Mn), 14.3 (Ni), 6.0 (Pb), 226 (Zn), and 2532 (Fe). Comparing trace element contents to limit values set by the German Fertilizer Ordinance showed that the mean contents of potentially toxic trace elements, such as Cd and Pb, were lower than their limit values in all groups of fertilizers. On the other hand, while a number of fertilizers contained a high content of some essential trace elements, particularly Fe, they were not labeled as such.

Analysis of trace metals in water by inductively coupled plasma emission spectrometry using sodium dibenzyldithiocarbamate for preconcentration

USGS Publications Warehouse

Smith, C.L.; Motooka, J.M.; Willson, W.R.

1984-01-01

Since concentrations of trace elements in most natural waters seldom exceed the ??g/L level, analysis of trace elements in natural waters by inductively coupled plasma emission spectrometry (ICP) requires a preconcentration procedure. The elements Ag, Bi, Cd, Co, Cu, Fe, Mo, Ni, Pb, Sn, V, W, and Zn were separated and concentrated from 500 mL of water by coprecipitating them with sodium dibenzyldithiocarbamate (NaDBDTC) using nickel or silver as a carrier. The precipitated trace elements were collected on a membrane filter, redissolved from the filter with hot nitric and hydrochloric acids, and analyzed using ICP. Recoveries for all the trace elements except tungsten exceeded 80%. Coprecipitation of trace elements with NaDBDTC eliminated the use of difficult-to-inject organic solvents, and NaDBDTC coprecipitated a wider array of trace elements than ammoniumpyrrolidinedithiocarbamate (APDC), another commonly used coprecipitate.

Spiders (Araneae) of Churchill, Manitoba: DNA barcodes and morphology reveal high species diversity and new Canadian records.

PubMed

Blagoev, Gergin A; Nikolova, Nadya I; Sobel, Crystal N; Hebert, Paul D N; Adamowicz, Sarah J

2013-11-26

Arctic ecosystems, especially those near transition zones, are expected to be strongly impacted by climate change. Because it is positioned on the ecotone between tundra and boreal forest, the Churchill area is a strategic locality for the analysis of shifts in faunal composition. This fact has motivated the effort to develop a comprehensive biodiversity inventory for the Churchill region by coupling DNA barcoding with morphological studies. The present study represents one element of this effort; it focuses on analysis of the spider fauna at Churchill. 198 species were detected among 2704 spiders analyzed, tripling the count for the Churchill region. Estimates of overall diversity suggest that another 10-20 species await detection. Most species displayed little intraspecific sequence variation (maximum <1%) in the barcode region of the cytochrome c oxidase subunit I (COI) gene, but four species showed considerably higher values (maximum = 4.1-6.2%), suggesting cryptic species. All recognized species possessed a distinct haplotype array at COI with nearest-neighbour interspecific distances averaging 8.57%. Three species new to Canada were detected: Robertus lyrifer (Theridiidae), Baryphyma trifrons (Linyphiidae), and Satilatlas monticola (Linyphiidae). The first two species may represent human-mediated introductions linked to the port in Churchill, but the other species represents a range extension from the USA. The first description of the female of S. monticola was also presented. As well, one probable new species of Alopecosa (Lycosidae) was recognized. This study provides the first comprehensive DNA barcode reference library for the spider fauna of any region. Few cryptic species of spiders were detected, a result contrasting with the prevalence of undescribed species in several other terrestrial arthropod groups at Churchill. Because most (97.5%) sequence clusters at COI corresponded with a named taxon, DNA barcoding reliably identifies spiders in the Churchill fauna. The capacity of DNA barcoding to enable the identification of otherwise taxonomically ambiguous specimens (juveniles, females) also represents a major advance for future monitoring efforts on this group.

Linking trace element variations with macronutrients and major cations in marine mussels Mytilus edulis and Perna viridis.

PubMed

Liu, Fengjie; Wang, Wen-Xiong

2015-09-01

Marine mussels have long been used as biomonitors of contamination of trace elements, but little is known about whether variation in tissue trace elements is significantly associated with those of macronutrients and major cations. The authors examined the variability of macronutrients and major cations and their potential relationships with bioaccumulation of trace elements. The authors analyzed the concentrations of macronutrients (C, N, P, S), major cations (Na, Mg, K, Ca), and trace elements (Al, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Pb) in the whole soft tissues of marine mussels Mytilus edulis and Perna viridis collected globally from 21 sites. The results showed that 12% to 84% of the variances in the trace elements was associated with major cations, and the tissue concentration of major cations such as Na and Mg in mussels was a good proxy for ambient seawater concentrations of the major cations. Specifically, bioaccumulation of most of the trace elements was significantly associated with major cations, and the relationships of major cations with trace cations and trace oxyanions were totally opposite. Furthermore, 14% to 69% of the variances in the trace elements were significantly associated with macronutrients. Notably, more than half of the variance in the tissue concentrations of As, Cd, V, Ba, and Pb was explained by the variance in macronutrients in one or both species. Because the tissue macronutrient concentrations were strongly associated with animal growth and reproduction, the observed coupling relationships indicated that these biological processes strongly influenced the bioaccumulation of some trace elements. The present study indicated that simultaneous quantification of macronutrients and major cations with trace elements can improve the interpretation of biomonitoring data. © 2015 SETAC.

[Proposal of new trace elements classification to be used in nutrition, oligotherapy and other therapeutics strategies].

PubMed

Ramírez Hernández, Javier; Bonete Pérez, María José; Martínez Espinosa, Rosa María

2014-12-17

1) to propose a new classification of the trace elements based on a study of the recently reported research; 2) to offer detailed and actualized information about trace elements. the analysis of the research results recently reported reveals that the advances of the molecular analysis techniques point out the importance of certain trace elements in human health. A detailed analysis of the catalytic function related to several elements not considered essential o probably essentials up to now is also offered. To perform the integral analysis of the enzymes containing trace elements informatics tools have been used. Actualized information about physiological role, kinetics, metabolism, dietetic sources and factors promoting trace elements scarcity or toxicity is also presented. Oligotherapy uses catalytic active trace elements with therapeutic proposals. The new trace element classification here presented will be of high interest for different professional sectors: doctors and other professions related to medicine; nutritionist, pharmaceutics, etc. Using this new classification and approaches, new therapeutic strategies could be designed to mitigate symptomatology related to several pathologies, particularly carential and metabolic diseases. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Rate-dependent behavior of the amorphous phase of spider dragline silk.

PubMed

Patil, Sandeep P; Markert, Bernd; Gräter, Frauke

2014-06-03

The time-dependent stress-strain behavior of spider dragline silk was already observed decades ago, and has been attributed to the disordered sequences in silk proteins, which compose the soft amorphous matrix. However, the actual molecular origin and magnitude of internal friction within the amorphous matrix has remained inaccessible, because experimentally decomposing the mechanical response of the amorphous matrix from the embedded crystalline units is challenging. Here, we used atomistic molecular dynamics simulations to obtain friction forces for the relative sliding of peptide chains of Araneus diadematus spider silk within bundles of these chains as a representative unit of the amorphous matrix in silk fibers. We computed the friction coefficient and coefficient of viscosity of the amorphous phase to be in the order of 10(-6) Ns/m and 10(4) Ns/m(2), respectively, by extrapolating our simulation data to the viscous limit. Finally, we used a finite element method for the amorphous phase, solely based on parameters derived from molecular dynamics simulations including the newly determined coefficient of viscosity. With this model the time scales of stress relaxation, creep, and hysteresis were assessed, and found to be in line with the macroscopic time-dependent response of silk fibers. Our results suggest the amorphous phase to be the primary source of viscosity in silk and open up the avenue for finite element method studies of silk fiber mechanics including viscous effects. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

A COGNITIVE PERSPECTIVE ON AGGRESSIVE MIMICRY

PubMed Central

JACKSON, ROBERT R.; CROSS, FIONA R.

2013-01-01

We use the term ‘aggressive mimic’ for predators that communicate with their prey by making signals to indirectly manipulate prey behaviour. For understanding why the aggressive mimic’s signals work, it is important to appreciate that these signals interface with the prey’s perceptual system, and that the aggressive mimic can be envisaged as playing mind games with its prey. Examples of aggressive mimicry vary from instances in which specifying a model is straight forward to instances where a concise characterisation of the model is difficult. However, the less straightforward examples of aggressive mimicry may be the more interesting examples in the context of animal cognition. In particular, there are spiders that prey on other spiders by entering their prey’s web and making signals. Web invasion brings about especially intimate contact with their prey’s perceptual system because the prey spider’s web is an important component of the prey spider’s sensory apparatus. For the web-invading spider, often there is also a large element of risk when practising aggressive mimicry because the intended prey is also a potential predator. This element of risk, combined with exceptionally intimate interfacing with prey perceptual systems, may have favoured the web-invading aggressive mimic’s strategy becoming strikingly cognitive in character. Yet a high level of flexibility may be widespread among aggressive mimics in general and, on the whole, we propose that research on aggressive mimicry holds exceptional potential for advancing our understanding of animal cognition. PMID:23976823

Trace elements have limited utility for studying migratory connectivity in shorebirds that winter in Argentina

USGS Publications Warehouse

Torres-Dowdall, J.; Farmer, A.H.; Abril, M.; Bucher, E.H.; Ridley, I.

2010-01-01

Trace-element analysis has been suggested as a tool for the study of migratory connectivity because (1) trace-element abundance varies spatially in the environment, (2) trace elements are assimilated into animals' tissues through the diet, and (3) current technology permits the analysis of multiple trace elements in a small tissue sample, allowing the simultaneous exploration of several elements. We explored the potential of trace elements (B, Na, Mg, Al, Si, P, S, K, Ca, Ti, Cr, Mn, Ni, Cu, Zn, As, Sr, Cs, Hg, Tl, Pb, Bi, Th, and U) to clarify the migratory connectivity of shorebirds that breed in North America and winter in southern South America. We collected 66 recently replaced secondary feathers from Red Knots (Calidris canutus) at three sites in Patagonia and 76 from White-rumped Sandpipers (C. fuscicollis) at nine sites across Argentina. There were significant differences in trace-element abundance in shorebird feathers grown at different nonbreeding sites, and annual variability within a site was small compared to variability among sites. Across Argentina, there was no large-scale gradient in trace elements. The lack of such a gradient restricts the application of this technique to questions concerning the origin of shorebirds to a small number of discrete sites. Furthermore, our results including three additional species, the Pectoral Sandpiper (C. melanotos), Wilson's Phalarope (Phalaropus tricolor), and Collared Plover (Charadrius collaris), suggest that trace-element profiles change as feathers age. Temporal instability of trace-element values could undermine their application to the study of migratory connectivity in shorebirds. ?? The Cooper Ornithological Society 2010.

Spider movement, UV reflectance and size, but not spider crypsis, affect the response of honeybees to Australian crab spiders.

PubMed

Llandres, Ana L; Rodríguez-Gironés, Miguel A

2011-02-16

According to the crypsis hypothesis, the ability of female crab spiders to change body colour and match the colour of flowers has been selected because flower visitors are less likely to detect spiders that match the colour of the flowers used as hunting platform. However, recent findings suggest that spider crypsis plays a minor role in predator detection and some studies even showed that pollinators can become attracted to flowers harbouring Australian crab spider when the UV contrast between spider and flower increases. Here we studied the response of Apis mellifera honeybees to the presence of white or yellow Thomisus spectabilis Australian crab spiders sitting on Bidens alba inflorescences and also the response of honeybees to crab spiders that we made easily detectable painting blue their forelimbs or abdomen. To account for the visual systems of crab spider's prey, we measured the reflectance properties of the spiders and inflorescences used for the experiments. We found that honeybees did not respond to the degree of matching between spiders and inflorescences (either chromatic or achromatic contrast): they responded similarly to white and yellow spiders, to control and painted spiders. However spider UV reflection, spider size and spider movement determined honeybee behaviour: the probability that honeybees landed on spider-harbouring inflorescences was greatest when the spiders were large and had high UV reflectance or when spiders were small and reflected little UV, and honeybees were more likely to reject inflorescences if spiders moved as the bee approached the inflorescence. Our study suggests that only the large, but not the small Australian crab spiders deceive their preys by reflecting UV light, and highlights the importance of other cues that elicited an anti-predator response in honeybees.

Spider Movement, UV Reflectance and Size, but Not Spider Crypsis, Affect the Response of Honeybees to Australian Crab Spiders

PubMed Central

Llandres, Ana L.; Rodríguez-Gironés, Miguel A.

2011-01-01

According to the crypsis hypothesis, the ability of female crab spiders to change body colour and match the colour of flowers has been selected because flower visitors are less likely to detect spiders that match the colour of the flowers used as hunting platform. However, recent findings suggest that spider crypsis plays a minor role in predator detection and some studies even showed that pollinators can become attracted to flowers harbouring Australian crab spider when the UV contrast between spider and flower increases. Here we studied the response of Apis mellifera honeybees to the presence of white or yellow Thomisus spectabilis Australian crab spiders sitting on Bidens alba inflorescences and also the response of honeybees to crab spiders that we made easily detectable painting blue their forelimbs or abdomen. To account for the visual systems of crab spider's prey, we measured the reflectance properties of the spiders and inflorescences used for the experiments. We found that honeybees did not respond to the degree of matching between spiders and inflorescences (either chromatic or achromatic contrast): they responded similarly to white and yellow spiders, to control and painted spiders. However spider UV reflection, spider size and spider movement determined honeybee behaviour: the probability that honeybees landed on spider-harbouring inflorescences was greatest when the spiders were large and had high UV reflectance or when spiders were small and reflected little UV, and honeybees were more likely to reject inflorescences if spiders moved as the bee approached the inflorescence. Our study suggests that only the large, but not the small Australian crab spiders deceive their preys by reflecting UV light, and highlights the importance of other cues that elicited an anti-predator response in honeybees. PMID:21359183

Trace elements in agroecosystems and impacts on the environment.

PubMed

He, Zhenli L; Yang, Xiaoe E; Stoffella, Peter J

2005-01-01

Trace elements mean elements present at low concentrations (mg kg-1 or less) in agroecosystems. Some trace elements, including copper (Cu), zinc (Zn), manganese (Mn), iron (Fe), molybdenum (Mo), and boron (B) are essential to plant growth and are called micronutrients. Except for B, these elements are also heavy metals, and are toxic to plants at high concentrations. Some trace elements, such as cobalt (Co) and selenium (Se), are not essential to plant growth but are required by animals and human beings. Other trace elements such as cadmium (Cd), lead (Pb), chromium (Cr), nickel (Ni), mercury (Hg), and arsenic (As) have toxic effects on living organisms and are often considered as contaminants. Trace elements in an agroecosystem are either inherited from soil parent materials or inputs through human activities. Soil contamination with heavy metals and toxic elements due to parent materials or point sources often occurs in a limited area and is easy to identify. Repeated use of metal-enriched chemicals, fertilizers, and organic amendments such as sewage sludge as well as wastewater may cause contamination at a large scale. A good example is the increased concentration of Cu and Zn in soils under long-term production of citrus and other fruit crops. Many chemical processes are involved in the transformation of trace elements in soils, but precipitation-dissolution, adsorption-desorption, and complexation are the most important processes controlling bioavailability and mobility of trace elements in soils. Both deficiency and toxicity of trace elements occur in agroecosystems. Application of trace elements in fertilizers is effective in correcting micronutrient deficiencies for crop production, whereas remediation of soils contaminated with metals is still costly and difficult although phytoremediation appears promising as a cost-effective approach. Soil microorganisms are the first living organisms subjected to the impacts of metal contamination. Being responsive and sensitive, changes in microbial biomass, activity, and community structure as a result of increased metal concentration in soil may be used as indicators of soil contamination or soil environmental quality. Future research needs to focus on the balance of trace elements in an agroecosystem, elaboration of soil chemical and biochemical parameters that can be used to diagnose soil contamination with or deficiency in trace elements, and quantification of trace metal transport from an agroecosystem to the environment.

Grain-size distribution and selected major and trace element concentrations in bed-sediment cores from the Lower Granite Reservoir and Snake and Clearwater Rivers, eastern Washington and northern Idaho, 2010

USGS Publications Warehouse

Braun, Christopher L.; Wilson, Jennifer T.; Van Metre, Peter C.; Weakland, Rhonda J.; Fosness, Ryan L.; Williams, Marshall L.

2012-01-01

Fifty subsamples from 15 cores were analyzed for major and trace elements. Concentrations of trace elements were low, with respect to sediment quality guidelines, in most cores. Typically, major and trace element concentrations were lower in the subsamples collected from the Snake River compared to those collected from the Clearwater River, the confluence of the Snake and Clearwater Rivers, and Lower Granite Reservoir. Generally, lower concentrations of major and trace elements were associated with coarser sediments (larger than 0.0625 millimeter) and higher concentrations of major and trace elements were associated with finer sediments (smaller than 0.0625 millimeter).

Nuclear microscopy in trace-element biology — from cellular studies to the clinic

NASA Astrophysics Data System (ADS)

Lindh, Ulf

1993-05-01

The concentration and distribution of trace and major elements in cells are of great interest in cell biology. PIXE can provide elemental concentrations in the bulk of cells or organelles as other bulk techniques such as atomic absorption spectrophotometry and nuclear activation analysis. Supplementary information, perhaps more exciting, on the intracellular distributions of trace elements can be provided using nuclear microscopy. Intracellular distributions of trace elements in normal and malignant cells are presented. The toxicity of mercury and cadmium can be prevented by supplementation of the essential trace element selenium. Some results from an experimental animal model are discussed. The intercellular distribution of major and trace elements in isolated blood cells, as revealed by nuclear microscopy, provides useful clinical information. Examples are given concerning inflammatory connective-tissue diseases and the chronic fatigue syndrome.

Nano-channels in the spider fang for the transport of Zn ions to cross-link His-rich proteins pre-deposited in the cuticle matrix.

PubMed

Politi, Yael; Pippel, Eckhard; Licuco-Massouh, Ana C J; Bertinetti, Luca; Blumtritt, Horst; Barth, Friedrich G; Fratzl, Peter

2017-01-01

We identify the presence of multiple vascular channels within the spider fang. These channels seem to serve the transport of zinc to the tip of the fang to cross-link the protein matrix by binding to histidine residues. According to amino acid and elemental analysis of fangs extracted shortly after ecdysis, His-rich proteins are deposited before Zn is incorporated into the cuticle. Microscopic and spectroscopic investigations in the electron microscope and synchrotron radiation experiments suggest that Zn ions are transported through these channels in a liable (yet unidentified) form, and then form stable complexes upon His binding. The resulting cross-linking through the Zn-His complexes is conferring hardness to the fang. Our observations of nano-channels serving the Zn-transport within the His-rich protein matrix of the fibre reinforced spider fang may also support recent bio-inspired attempts to design artificial polymeric vascular materials for self-healing and in-situ curing. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Factors affecting trace element content in periurban market garden subsoil in Yunnan Province, China.

PubMed

Zu, Yanqun; Bock, Laurent; Schvartz, Christian; Colinet, Gilles; Li, Yuan

2011-01-01

Field investigations were conducted to measure subsoil trace element content and factors influencing content in an intensive periurban market garden in Chenggong County, Yunnan Province, South-West China. The area was divided into three different geomorphological units: specifically, mountain (M), transition (T) and lacustrine (L). Mean trace element content in subsoil were determined for Pb (58.2 mg/kg), Cd (0.89 mg/kg), Cu (129.2 mg/kg), and Zn (97.0 mg/kg). Strong significant relationships between trace element content in topsoil and subsoil were observed. Both Pb and Zn were accumulated in topsoil (RTS (ratio of mean trace element in topsoil to subsoil) of Pb and Zn > or =1.0) and Cd and Cu in subsoil (RTS of Cd and Cu < or = 1.0). Subsoil trace element content was related to relief, stoniness, soil color, clay content, and cation exchange capacity. Except for 7.5 YR (yellow-red) color, trace element content increased with color intensity from brown to reddish brown. Significant positive relationships were observed between Fe content and that of Pb and Cu. Trace element content in mountain unit subsoil was higher than in transition and lacustrine units (M > T > L), except for Cu (T > M > L). Mean trace element content in calcareous subsoil was higher than in sandstone and shale. Mean trace element content in clay texture subsoil was higher than in sandy and sandy loam subsoil, and higher Cu and Zn content in subsoil with few mottles. It is possible to model Pb, Cd, Cu, and Zn distribution in subsoil physico-chemical characteristics to help improve agricultural practice.

Trace elements at the intersection of marine biological and geochemical evolution

USGS Publications Warehouse

Robbins, Leslie J.; Lalonde, Stefan V.; Planavsky, Noah J.; Partin, Camille A.; Reinhard, Christopher T.; Kendall, Brian; Scott, Clinton T.; Hardisty, Dalton S.; Gill, Benjamin C.; Alessi, Daniel S.; Dupont, Christopher L.; Saito, Mak A.; Crowe, Sean A.; Poulton, Simon W.; Bekker, Andrey; Lyons, Timothy W.; Konhauser, Kurt O.

2016-01-01

Life requires a wide variety of bioessential trace elements to act as structural components and reactive centers in metalloenzymes. These requirements differ between organisms and have evolved over geological time, likely guided in some part by environmental conditions. Until recently, most of what was understood regarding trace element concentrations in the Precambrian oceans was inferred by extrapolation, geochemical modeling, and/or genomic studies. However, in the past decade, the increasing availability of trace element and isotopic data for sedimentary rocks of all ages has yielded new, and potentially more direct, insights into secular changes in seawater composition – and ultimately the evolution of the marine biosphere. Compiled records of many bioessential trace elements (including Ni, Mo, P, Zn, Co, Cr, Se, and I) provide new insight into how trace element abundance in Earth's ancient oceans may have been linked to biological evolution. Several of these trace elements display redox-sensitive behavior, while others are redox-sensitive but not bioessential (e.g., Cr, U). Their temporal trends in sedimentary archives provide useful constraints on changes in atmosphere-ocean redox conditions that are linked to biological evolution, for example, the activity of oxygen-producing, photosynthetic cyanobacteria. In this review, we summarize available Precambrian trace element proxy data, and discuss how temporal trends in the seawater concentrations of specific trace elements may be linked to the evolution of both simple and complex life. We also examine several biologically relevant and/or redox-sensitive trace elements that have yet to be fully examined in the sedimentary rock record (e.g., Cu, Cd, W) and suggest several directions for future studies.

Trace element exposure of whooper swans (Cygnus cygnus) wintering in a marine lagoon (Swan Lake), northern China.

PubMed

Wang, Feng; Xu, Shaochun; Zhou, Yi; Wang, Pengmei; Zhang, Xiaomei

2017-06-30

Trace element poisoning remains a great threat to various waterfowl and waterbirds throughout the world. In this study, we determined the trace element exposure of herbivorous whooper swans (Cygnus cygnus) wintering in Swan Lake (Rongcheng), an important swan protection area in northern China. A total of 70 samples including abiotic factors (seawater, sediments), food sources (seagrass, macroalgae), feathers and feces of whooper swans were collected from the marine lagoon during the winters of 2014/2015 and 2015/2016. Concentrations of Cu, Zn, Pb, Cr, Cd, Hg and As were determined to investigate the trace element exposure of whooper swans wintering in the area. Results showed that there was an increasing trend in sediment trace element concentrations, compared with historical data. The trace element concentrations in swan feces most closely resembled those of Zostera marina leaves, especially for Cd and Cr. The Zn and Hg concentrations in the swan feces (49.57 and 0.01mg/kg, respectively) were lower than the minimum values reported in the literature for other waterfowls, waterbirds and terrestrial birds. However, the concentrations of the other five trace elements fell within the lower and mediate range of values reported for birds across the world. These results suggest that the whooper swans wintering in Swan Lake, Rongcheng are not suffering severe trace element exposure; however, with the increasing input of trace elements to the lagoon, severe adverse impacts may occur in the future, and we therefore suggest that the input of trace elements to this area should be curbed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heavy Metals and Related Trace Elements.

ERIC Educational Resources Information Center

Leland, Harry V.; And Others

1978-01-01

Presents a literature review of heavy metals and related trace elements in the environment, covering publications of 1976-77. This review includes: (1) trace treatment in natural water and in sediments; and (2) bioaccumulation and toxicity of trace elements. A list of 466 references is presented. (HM)

Meteoritic trace element toxification and the terminal Mesozoic mass extinction

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

Dickson, S.M.; Erickson, D.J. III

1985-01-01

Calculations of trace element fluxes to the earth associated with 5 and 10 kilometer diameter Cl chondrites and iron meteorites are presented. The data indicate that the masses of certain trace elements contained in the bolide, such as Fe, Co, Ni, Cr, Pb, and Cu, are as large as or larger than the world ocean burden. The authors believe that this pulse of trace elements was of sufficient magnitude to perturb the biogeochemical cycles operative 65 million years ago, a probably time of meteorite impact. Geochemical anomalies in Cretaceous-Tertiary boundary sediments suggest that elevated concentrations of trace elements may havemore » persisted for thousands of years in the ocean. Through direct exposure and bioaccumulation, many trophic levels of the global food chain, including that of the dinosaurs, would have been adversely affected by these meteoritic trace elements. The trace element toxification hypothesis may account for the selective extinction of both marine and terrestrial species in the enigmatic terminal Mesozoic event.« less

Trace element abundances in major minerals of Late Permian coals from southwestern Guizhou province, China

USGS Publications Warehouse

Zhang, Jiahua; Ren, D.; Zheng, C.; Zeng, R.; Chou, C.-L.; Liu, J.

2002-01-01

Fourteen samples of minerals were separated by handpicking from Late Permian coals in southwestern Guizhou province, China. These 14 minerals were nodular pyrite, massive recrystallized pyrite, pyrite deposited from low-temperature hydrothermal fluid and from ground water; clay minerals; and calcite deposited from low-temperature hydrothermal fluid and from ground water. The mineralogy, elemental composition, and distribution of 33 elements in these samples were studied by optical microscopy, scanning electron microscope equipped with energy-dispersive X-ray spectrometer (SEM-EDX), X-ray diffraction (XRD), cold-vapor atomic absorption spectrometry (CV-AAS), atomic fluorescence spectrometry (AFS), inductively coupled-plasma mass spectrometry (ICP-MS), and ion-selective electrode (ISE). The results show that various minerals in coal contain variable amounts of trace elements. Clay minerals have high concentrations of Ba, Be, Cs, F, Ga, Nb, Rb, Th, U, and Zr. Quartz has little contribution to the concentration of trace elements in bulk coal. Arsenic, Mn, and Sr are in high concentrations in calcite. Pyrite has high concentrations of As, Cd, Hg, Mo, Sb, Se, Tl, and Zn. Different genetic types of calcite in coal can accumulate different trace elements; for example Ba, Co, Cr, Hg, Ni, Rb, Sn, Sr, and Zn are in higher concentrations in calcite deposited from low-temperature hydrothermal fluid than in that deposited from ground water. Furthermore, the concentrations of some trace elements are quite variable in pyrite; different genetic types of pyrites (Py-A, B, C, D) have different concentrations of trace elements, and the concentrations of trace elements are also different in pyrite of low-temperature hydrothermal origin collected from different locations. The study shows that elemental concentration is rather uniform in a pyrite vein. There are many micron and submicron mosaic pyrites in a pyrite vein, which is enriched in some trace elements, such as As and Mo. The content of trace element in pyrite vein depends upon the content of mosaic pyrite and of trace elements in it. Many environmentally sensitive trace elements are mainly contained in the minerals in coal, and hence the physical coal cleaning techniques can remove minerals from coal and decrease the emissions of potentially hazardous trace elements. ?? 2002 Elsevier Science B.V. All rights reserved.

Trace elemental analysis of human breast cancerous blood by advanced PC-WDXRF technique

NASA Astrophysics Data System (ADS)

Singh, Ranjit; Kainth, Harpreet Singh; Prasher, Puneet; Singh, Tejbir

2018-03-01

The objective of this work is to quantify the trace elements of healthy and non-healthy blood samples by using advanced polychromatic source based wavelength dispersive X-ray fluorescence (PC-WDXRF) technique. The imbalances in trace elements present in the human blood directly or indirectly lead to the carcinogenic process. The trace elements 11Na, 12Mg, 15P, 16S, 17Cl, 19K, 20Ca, 26Fe, 29Cu and 30Zn are identified and their concentrations are estimated. The experimental results clearly discuss the variation and role of various trace elements present in the non-healthy blood samples relative to the healthy blood samples. These results establish future guidelines to probe the possible roles of essential trace elements in the breast carcinogenic processes. The instrumental sensitivity and detection limits for measuring the elements in the atomic range 11 ≤ Z ≤ 30 have also been discussed in the present work.

INAA Application for Trace Element Determination in Biological Reference Material

NASA Astrophysics Data System (ADS)

Atmodjo, D. P. D.; Kurniawati, S.; Lestiani, D. D.; Adventini, N.

2017-06-01

Trace element determination in biological samples is often used in the study of health and toxicology. Determination change to its essentiality and toxicity of trace element require an accurate determination method, which implies that a good Quality Control (QC) procedure should be performed. In this study, QC for trace element determination in biological samples was applied by analyzing the Standard Reference Material (SRM) Bovine muscle 8414 NIST using Instrumental Neutron Activation Analysis (INAA). Three selected trace element such as Fe, Zn, and Se were determined. Accuracy of the elements showed as %recovery and precision as %coefficient of variance (%CV). The result showed that %recovery of Fe, Zn, and Se were in the range between 99.4-107%, 92.7-103%, and 91.9-112%, respectively, whereas %CV were 2.92, 3.70, and 5.37%, respectively. These results showed that INAA method is precise and accurate for trace element determination in biological matrices.

New insights into trace element wet deposition in the Himalayas: amounts, seasonal patterns, and implications.

PubMed

Cong, Zhiyuan; Kang, Shichang; Zhang, Yulan; Gao, Shaopeng; Wang, Zhongyan; Liu, Bin; Wan, Xin

2015-02-01

Our research provides the first complete year-long dataset of wet deposition of trace elements in the high Himalayas based on a total of 42 wet deposition events on the northern slope of Mt. Qomolangma (Everest). Except for typical crustal elements (Al, Fe, and Mn), the concentration level of most trace elements (Sc, V, Cr, Co, Ni, Cu, Zn, As, Mo, Cd, Sn, Cs, Pb, Bi, and U) are generally comparable to those preserved in snow pits and ice cores from the nearby East Rongbuk Glacier. Cadmium was the element most affected by anthropogenic emissions. No pronounced seasonal variations are observed for most trace elements despite different transport pathways. In our study, the composition of wet precipitation reflects a regional background condition and is not clearly related to specific source regions. For the trace element record from ice cores and snow pits in the Himalayas, it could be deduced that the pronounced seasonal patterns were caused by the dry deposition of trace elements (aerosols) during their long exposure to the atmosphere after precipitation events. Our findings are of value for the understanding of the trace element deposition mechanisms in the Himalayas.

The effect of tissue structure and soil chemistry on trace element uptake in fossils

NASA Astrophysics Data System (ADS)

Hinz, Emily A.; Kohn, Matthew J.

2010-06-01

Trace element profiles for common divalent cations (Sr, Zn, Ba), rare-earth elements (REE), Y, U, and Th were measured in fossil bones and teeth from the c. 25 ka Merrell locality, Montana, USA, by using laser-ablation ICP-MS. Multiple traverses in teeth were transformed into 2-D trace element maps for visualizing structural influences on trace element uptake. Trace element compositions of different soils from the fossil site were also analyzed by solution ICP-MS, employing progressive leaches that included distilled H 2O, 0.1 M acetic acid, and microwave digestion in concentrated HCl-HNO 3. In teeth, trace element uptake in enamel is 2-4 orders of magnitude slower than in dentine, forming an effective trace element barrier. Uptake in dentine parallel to the dentine-enamel interface is enhanced by at least 2 orders of magnitude compared to transverse, causing trace element "plumes" down the tooth core. In bone, U, Ba and Sr are nearly homogeneous, implying diffusivities ˜5 orders of magnitude faster than in enamel and virtually complete equilibration with host soils. In contrast all REE show strong depletions inward, with stepwise linear segments in log-normal or inverse complementary error function plots; these data require a multi-medium diffusion model, with about 2 orders of magnitude difference in slowest vs. fastest diffusivities. Differences in REE diffusivities in bone (slow) vs. dentine (fast) reflect different partition coefficients ( Kd's). Although acid leaches and bulk digestion of soils yield comparable fossil-soil Kd's among different elements, natural solutions are expected to be neutral to slightly basic. Distilled H 2O leachates instead reveal radically different Kd's in bone for REE than for U-Sr-Ba, suggest orders of magnitude lower effective diffusivities for REE, and readily explain steep vs. flat profiles for REE vs. U-Sr-Ba, respectively. Differences among REE Kd's and diffusivities may explain inward changes in Ce anomalies. Acid washes and bulk soil compositions yield misleading Kd's for many trace elements, especially the REE, and H 2O-leaches are preferred. Patterns of trace element distributions indicate diagenetic alteration at all scales, including enamel, and challenge the use of trace elements in paleodietary studies.

A Global Overview of Exposure Levels and Biological Effects of Trace Elements in Penguins.

PubMed

Espejo, Winfred; Celis, José E; GonzÃlez-Acuña, Daniel; Banegas, Andiranel; Barra, Ricardo; Chiang, Gustavo

2018-01-01

Trace elements are chemical contaminants that can be present almost anywhere on the planet. The study of trace elements in biotic matrices is a topic of great relevance for the implications that it can have on wildlife and human health. Penguins are very useful, since they live exclusively in the Southern Hemisphere and represent about 90% of the biomass of birds of the Southern Ocean. The levels of trace elements (dry weight) in different biotic matrices of penguins were reviewed here. Maps of trace element records in penguins were included. Data on exposure and effects of trace elements in penguins were collected from the literature. The most reported trace elements in penguins are aluminum, arsenic, cadmium, lead, mercury, copper, zinc, and manganese. Trace elements have been measured in 11 of the 18 species of penguins. The most studied biotic matrices are feathers and excreta. Most of the studies have been performed in Antarctica and subantarctic Islands. Little is known about the interaction among metals, which could provide better knowledge about certain mechanisms of detoxification in penguins. Future studies of trace elements in penguins must incorporate other metals such as vanadium, cobalt, nickel, and chromium. Data of metals in the species such as Eudyptes pachyrhynchus, Eudyptes moseleyi, Eudyptes sclateri, Eudyptes robustus, Eudyptes schlegeli, Spheniscus demersus, Spheniscus mendiculus, and Megadyptes antipodes are urged. It is important to correlate levels of metals in different biotic matrices with the effects on different species and in different geographic locations.

Trace element supplementation in the biogas production from wheat stillage--optimization of metal dosing.

PubMed

Schmidt, Thomas; Nelles, Michael; Scholwin, Frank; Pröter, Jürgen

2014-09-01

A trace element dosing strategy for the anaerobic digestion of wheat stillage was developed in this study. Mesophilic CSTR reactors were operated with the sulfuric substrate wheat stillage in some cases under trace element deficiency. After supplementing trace elements during the start-up, one of the elements of Fe, Ni, Co, Mo, and W were depleted in one digester while still augmenting the other elements to determine minimum requirements for each element. The depletion of Fe and Ni resulted in a rapid accumulation of volatile fatty acids while Co and W seem to have a long-term effect. Based on the results it was possible to reduce the dosing of trace elements, which is positive with reference to economic and environmental aspects. Copyright © 2014 Elsevier Ltd. All rights reserved.

Flee or fight: ontogenetic changes in the behavior of cobweb spiders in encounters with spider-hunting wasps.

PubMed

Uma, Divya B; Weiss, Martha R

2012-12-01

An animal's body size plays a predominant role in shaping its interspecific interactions, and, in encounters between two predators, often determines which shall be predator and which shall be prey. Spiders are top predators of insects, yet can fall prey to mud-dauber wasps that provision their larval nests with paralyzed spiders. Here we examined predator-prey interactions between Chalybion californicum (Saussure) (Sphecidae), a mud-dauber wasp, and Parasteatoda tepidariorum C. L. Koch (Theridiidae), a cobweb spider. We examined whether a spider's size influences its response to an attacking wasp, and report a size-dependent change in spider behavior: small-sized spiders fled, whereas medium- and large-sized spiders fought in response to wasp attacks. From the wasps' perspective, we examined whether spider size influences a wasp's hunting behavior and capture success. We found that wasps commonly approached small spiders, but were much less likely to approach medium and large spiders. However, wasp capture success did not vary with spider size. We also report a strategy used by Chalybion wasps toward cobweb spiders that is consistent with an interpretation of aggressive mimicry.

Loess as an environmental archive of atmospheric trace element deposition

NASA Astrophysics Data System (ADS)

Blazina, T.; Winkel, L. H.

2013-12-01

Environmental archives such as ice cores, lake sediment cores, and peat cores have been used extensively to reconstruct past atmospheric deposition of trace elements. These records have provided information about how anthropogenic activities such as mining and fossil fuel combustion have disturbed the natural cycles of various atmospherically transported trace elements (e.g. Pb, Hg and Se). While these records are invaluable for tracing human impacts on such trace elements, they often provide limited information about the long term natural cycles of these elements. An assumption of these records is that the observed variations in trace element input, prior to any assumed anthropogenic perturbations, represent the full range of natural variations. However, records such as those mentioned above which extend back to a maximum of ~400kyr may not capture the potentially large variations of trace element input occurring over millions of years. Windblown loess sediments, often representing atmospheric deposition over time scales >1Ma, are the most widely distributed terrestrial sediments on Earth. These deposits have been used extensively to reconstruct continental climate variability throughout the Quaternary and late Neogene periods. In addition to being a valuable record of continental climate change, loess deposits may represent a long term environmental archive of atmospheric trace element deposition and may be combined with paleoclimate records to elucidate how fluctuations in climate have impacted the natural cycle of such elements. Our research uses the loess-paleosol deposits on the Chinese Loess Plateau (CLP) to quantify how atmospheric deposition of trace elements has fluctuated in central China over the past 6.8Ma. The CLP has been used extensively to reconstruct past changes of East Asian monsoon system (EAM). We present a suite of trace element concentration records (e.g. Pb, Hg, and Se) from the CLP which exemplifies how loess deposits can be used as an environmental archive to reconstruct long term natural variations in atmospheric trace element input. By comparing paleomonsoon proxy data with geochemical data we can directly correlate variations in atmospheric trace element input to fluctuations in the EAM. For example we are able to link Se input into the CLP to EAM derived precipitation. In interglacial climatic periods from 2.3-1.56Ma and 1.50-1.29Ma, we find very strong positive correlations between Se concentration and the summer monsoon index, a proxy for effective precipitation. In later interglacial periods from 1.26-0.83Ma and 0.78-0.16Ma, we find dust input plays a greater role. Our findings demonstrate that the CLP is a valuable environmental archive of atmospheric trace element deposition and suggest that other loess deposits worldwide may serve as useful records for investigating long term natural variations in atmospheric trace element cycling.

Serum Concentrations of Trace Elements in Patients with Tuberculosis and Its Association with Treatment Outcome

PubMed Central

Choi, Rihwa; Kim, Hyoung-Tae; Lim, Yaeji; Kim, Min-Ji; Kwon, O Jung; Jeon, Kyeongman; Park, Hye Yun; Jeong, Byeong-Ho; Koh, Won-Jung; Lee, Soo-Youn

2015-01-01

Deficiencies in essential trace elements are associated with impaired immunity in tuberculosis infection. However, the trace element concentrations in the serum of Korean patients with tuberculosis have not yet been investigated. This study aimed to compare the serum trace element concentrations of Korean adult patients with tuberculosis with noninfected controls and to assess the impact of serum trace element concentration on clinical outcome after antituberculosis treatment. The serum concentrations of four trace elements in 141 consecutively recruited patients with tuberculosis and 79 controls were analyzed by inductively coupled plasma-mass spectrometry. Demographic characteristics were also analyzed. Serum cobalt and copper concentrations were significantly higher in patients with tuberculosis compared with controls, while zinc and selenium concentrations were significantly lower (p < 0.01). Moreover, serum selenium and zinc concentrations were positively correlated (ρ = 0.41, p < 0.05). A high serum copper concentration was associated with a worse clinical outcome, as assessed after one month of antituberculosis therapy. Specifically, culture-positive patients had higher serum copper concentrations than culture-negative patients (p < 0.05). Patients with tuberculosis had altered serum trace element concentrations. Further research is needed to elucidate the roles of individual trace elements and to determine their clinical impact on patients with tuberculosis. PMID:26197334

[Contents of ten trace elements in Epimedium acuminatum Franch. and its different processed products].

PubMed

Chen, H L; Wang, J K; Ren, Y Q; Wu, Z Y

2001-03-01

Determine and compare the contents of ten trace elements in crude E. acuminatum and its three different processed products. Using flame atomic absorption spectrometry. The ten trace elements were found in both the crude drug and its three processed products, and in terms of contents some of the trace elements in all the three processed products are higher than those in the crude drug. According to the trace element contents, the three processed products of E. acuminatum have their own advantages. It is thus suggested that thoroughgoing clinical and experimental researches be performed anew for the long-shelved processing methods.

A Model Plant for a Biology Curriculum: Spider Flower ("Cleome Hasslerana L.")

ERIC Educational Resources Information Center

Marquard, Robert D.; Steinback, Rebecca

2009-01-01

Major advances in fundamental science are developed using model systems. Classic examples of model systems include Mendel's work with the common garden pea ("Pisium sativa"), classic inheritance work by Morgan with the fruit fly ("Drosophila"), developmental studies with the nematode ("C. elegans"), and transposable elements in maize ("Zea…

The Effects of Various Amendments on Trace Element Stabilization in Acidic, Neutral, and Alkali Soil with Similar Pollution Index

PubMed Central

Kim, Min-Suk; Min, Hyun-Gi; Lee, Sang-Hwan; Kim, Jeong-Gyu

2016-01-01

Many studies have examined the application of soil amendments, including pH change-induced immobilizers, adsorbents, and organic materials, for soil remediation. This study evaluated the effects of various amendments on trace element stabilization and phytotoxicity, depending on the initial soil pH in acid, neutral, and alkali conditions. As in all types of soils, Fe and Ca were well stabilized on adsorption sites. There was an effect from pH control or adsorption mechanisms on the stabilization of cationic trace elements from inorganic amendments in acidic and neutral soil. Furthermore, acid mine drainage sludge has shown great potential for stabilizing most trace elements. In a phytotoxicity test, the ratio of the bioavailable fraction to the pseudo-total fraction significantly affected the uptake of trace elements by bok choy. While inorganic amendments efficiently decreased the bioavailability of trace elements, significant effects from organic amendments were not noticeable due to the short-term cultivation period. Therefore, the application of organic amendments for stabilizing trace elements in agricultural soil requires further study. PMID:27835687

Assessment of trace element contamination of urban surface soil at informal industrial sites in a low-income country.

PubMed

Kanda, Artwell; Ncube, France; Hwende, Tamuka; Makumbe, Peter

2018-05-29

Trace elements released by human activity are ubiquitously detected in surface soil. The trace element contamination statuses of 20 sampling stations at two busy informal industrial sites of Harare city, Zimbabwe, were evaluated using geochemical indices. Spectrophotometric determinations of concentrations of trace elements in surface soil indicated generally higher values than the reference site and the average upper earth's crust. High contamination factors were observed for trace elements across sampling stations at Gazaland and Siyaso informal industrial sites. Concentrations exhibited heterogeneous distribution of trace elements in surface soil varying with the nature of activity at a sampling station. The pollution load index and degree of contamination suggested highly contaminated surface soil with Cd, Cu and Pb particularly where the following activities were done: (1) welding, (2) automobile maintenance and (3) waste dumping. These results may be very important to reduce soil contamination. Paving surfaces may help to reduce dispersal of trace elements deposited on surface soil to other stations and minimise human exposure via inhalation and contact.

Risk assessment of trace elements in cultured freshwater fishes from Jiangxi province, China.

PubMed

Zhang, Li; Zhang, Dawen; Wei, Yihua; Luo, Linguan; Dai, Tingcan

2014-04-01

The levels of trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Se, and Zn) in eight species of cultured freshwater fishes from Jiangxi province were determined by inductively coupled plasma-mass spectroscopy. All the studied trace element levels in fish muscles from Jiangxi province did not exceed Chinese national standard and European Union standard, and they were often lower than previous studies. The calculated target hazard quotient values for all the studied trace elements in fish samples were much less than 1, suggesting that the studied trace elements in fish muscles from Jiangxi province had not pose obvious health hazards to consumers. As and Cd concentrations in northern snakehead were much higher than that in other fishes, demonstrating that this fish species could be valuable as a bioindicator of As and Cd in environmental surveys. In addition, the highest concentrations of Fe, Zn, and moderate contents of other essential trace elements in crucian carp indicated that crucian carp could be a good nutrient source of essential trace elements for human health.

The Effects of Various Amendments on Trace Element Stabilization in Acidic, Neutral, and Alkali Soil with Similar Pollution Index.

PubMed

Kim, Min-Suk; Min, Hyun-Gi; Lee, Sang-Hwan; Kim, Jeong-Gyu

2016-01-01

Many studies have examined the application of soil amendments, including pH change-induced immobilizers, adsorbents, and organic materials, for soil remediation. This study evaluated the effects of various amendments on trace element stabilization and phytotoxicity, depending on the initial soil pH in acid, neutral, and alkali conditions. As in all types of soils, Fe and Ca were well stabilized on adsorption sites. There was an effect from pH control or adsorption mechanisms on the stabilization of cationic trace elements from inorganic amendments in acidic and neutral soil. Furthermore, acid mine drainage sludge has shown great potential for stabilizing most trace elements. In a phytotoxicity test, the ratio of the bioavailable fraction to the pseudo-total fraction significantly affected the uptake of trace elements by bok choy. While inorganic amendments efficiently decreased the bioavailability of trace elements, significant effects from organic amendments were not noticeable due to the short-term cultivation period. Therefore, the application of organic amendments for stabilizing trace elements in agricultural soil requires further study.

Methods for detecting the mobility of trace elements during medium-temperature pyrolysis

USGS Publications Warehouse

Shiley, R.H.; Konopka, K.L.; Cahill, R.A.; Hinckley, C.C.; Smith, Gerard V.; Twardowska, H.; Saporoschenko, Mykola

1983-01-01

The mobility (volatility) of trace elements in coal during pyrolysis has been studied for distances of up to 40 cm between the coal and the trace element collector, which was graphite or a baffled solvent trap. Nineteen elements not previously recorded as mobile were detected. ?? 1983.

The role of high-energy synchrotron radiation in biomedical trace element research

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

Pounds, J.G.; Long, G.J.; Kwiatek, W.M.

1987-01-01

This paper will present the results of an investigation of the distribution of essential elements in the normal hepatic lobule. the liver is the organ responsible for metabolism and storage of most trace elements. Although parenchymal hepatocytes are rather uniform histologically, morphometry, histochemistry, immunohistochemistry, and microdissection with microchemical investigations have revealed marked heterogeneity on a functional and biochemical level. Hepatocytes from the periportal and perivenous zones of the liver parrenchyma differ in oxidative energy metabolism, glucose uptake and output, unreagenesis, biotransformation, bile acid secretion, and palsma protein synthesis and secretion. Although trace elements are intimately involved in the regulation andmore » maintenance of these functions, little is known regarding the heterogeneity of trace element localization of the liver parenchyma. Histochemical techniques for trace elements generally give high spatial resolution, but lack specificity and stoichiometry. Microdissection has been of marginal usefulness for trace element analyses due to the very small size of the dissected parenchyma. The characteristics of the high-energy x-ray microscope provide an effective approach for elucidating the trace element content of these small biological structures or regions. 5 refs., 1 fig., 1 tab.« less

The influence of carbon, sulfur, and silicon on trace element partitioning in iron alloys

NASA Astrophysics Data System (ADS)

Han, J.; Van Orman, J. A.; Crispin, K. L.; Ash, R. D.

2014-12-01

Non-metallic light elements are important constituents of planetary cores and have a strong influence on the partitioning behavior of trace elements. Planetary cores may contain a wide range of non-metallic light elements, including H, N, S, P, Si, and C. Under highly reducing conditions, such as those that are thought to have pertained during the formation of Mercury's core, Si and C, in addition to sulfur, may be particularly important constituents. Each of these elements may strongly effect and have a different impact on the partitioning behavior of trace elements but their combined effects on trace element partitioning have not been quantified. We investigated the partitioning behavior of more than 25 siderophile trace elements within the Fe-S-C-Si system with varying concentrations of C, S, and Si. The experiments were performed under pressures varying from 1 atm to 2 GPa and temperatures ranging from 1200˚C to 1450˚C. All experiments produced immiscible liquids, one enriched in Si and C, and the other predominantly FeS. We found some highly siderophile elements including Os, Ru, Ir, and Re are much more enriched in Fe-Si-C phase than in Fe-S phase, whereas other trace elements like V, Co, Ag, Hf, and Pb are enriched in S-rich phase. However, not all the trace elements enriched in Fe-Si-C phase are repelled by sulfur. Elements like Re and Ru could have different partitioning trends if sulfur concentration in S-rich phase rises. The partitioning behavior of these trace elements could enhance our understanding of the differentiation of Mercury's core under oxygen-poor conditions.

Maternal transfer of trace elements in the Atlantic horseshoe crab (Limulus polyphemus).

PubMed

Bakker, Aaron K; Dutton, Jessica; Sclafani, Matthew; Santangelo, Nicholas

2017-01-01

The maternal transfer of trace elements is a process by which offspring may accumulate trace elements from their maternal parent. Although maternal transfer has been assessed in many vertebrates, there is little understanding of this process in invertebrate species. This study investigated the maternal transfer of 13 trace elements (Ag, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn) in Atlantic horseshoe crab (Limulus polyphemus) eggs and compared concentrations to those in adult leg and gill tissue. For the majority of individuals, all trace elements were transferred, with the exception of Cr, from the female to the eggs. The greatest concentrations on average transferred to egg tissue were Zn (140 µg/g), Cu (47.8 µg/g), and Fe (38.6 µg/g) for essential elements and As (10.9 µg/g) and Ag (1.23 µg/g) for nonessential elements. For elements that were maternally transferred, correlation analyses were run to assess if the concentration in the eggs were similar to that of adult tissue that is completely internalized (leg) or a boundary to the external environment (gill). Positive correlations between egg and leg tissue were found for As, Hg, Se, Mn, Pb, and Ni. Mercury, Mn, Ni, and Se were the only elements correlated between egg and gill tissue. Although, many trace elements were in low concentration in the eggs, we speculate that the higher transfer of essential elements is related to their potential benefit during early development versus nonessential trace elements, which are known to be toxic. We conclude that maternal transfer as a source of trace elements to horseshoe crabs should not be overlooked and warrants further investigation.

Remediation using trace element humate surfactant

DOEpatents

Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

2016-08-30

A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

ARMY GAS-COOLED REACTOR SYSTEMS PROGRAM. Quarterly Progress Report, October 1-December 31, 1963

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

None

1964-02-15

The ML-1 power plant did not operate during the report period; low power reactor physics and shielding experiments were conducted with the ML-1 reactor. Evaluation of moderate corrosion observed on aluminum parts exposed to the ML-1 shield solution indicated no loss of performance capability. Preliminary tests showed that the corrosion probably was caused by heavy metal ions or chlorides in the solution, Massive corrosion observed on the ML-1 fuel element lower spiders was attributed to sub-standard material; failure of some spiders was attributed to a combination of corrosion and sub-standard fabrication. Evaluation indicated that the upper spiders will perform satisfactorilymore » for the design lifetime. Modification, repair, and reassembly of the CSN-1A t-c set was completed. Operation demonstrated bearing stability, but showed that the turbine effective flow area was too large. A bypass flow path in the turbine was being corrected. The TCS-670 t-c set will be stored indefinitely. Since a commercial alternator will be used for the ML-1A, further development of the brushless alternator was postponed indefinitely. Evaluation revealed that the ML-1 improved precooler design was not compatible with ML-1A requirements. Operntion of the IB-17R-2 and -3 test elements in the GETR continued without incident. Preliminary design of the ML-1A power plant was initiated. Design of modifications to the GCRE facility to adapt it to testing the ML-1 reactor skid was initiated. (auth)« less

Trace element and stable isotope analysis of fourteen species of marine invertebrates from the Bay of Fundy, Canada.

PubMed

English, Matthew D; Robertson, Gregory J; Mallory, Mark L

2015-12-15

The Bay of Fundy, Canada, is a macrotidal bay with a highly productive intertidal zone, hosting a large abundance and diversity of marine invertebrates. We analysed trace element concentrations and stable isotopic values of δ(15)N and δ(13)C in 14 species of benthic marine invertebrates from the Bay of Fundy's intertidal zone to investigate bioaccumulation or biodilution of trace elements in the lower level of this marine food web. Barnacles (Balanus balanus) consistently had significantly greater concentrations of trace elements compared to the other species studied, but otherwise we found low concentrations of non-essential trace elements. In the range of trophic levels that we studied, we found limited evidence of bioaccumulation or biodilution of trace elements across species, likely due to the species examined occupying similar trophic levels in different food chains. Copyright © 2015 Elsevier Ltd. All rights reserved.

Distribution and environmental assessment of trace elements contamination of water, sediments and flora from Douro River estuary, Portugal.

PubMed

Ribeiro, C; Couto, C; Ribeiro, A R; Maia, A S; Santos, M; Tiritan, M E; Pinto, E; Almeida, A A

2018-10-15

The present study evaluated the content and distribution of several trace elements (Li, Be, Al, V, Cr, Co, Ni, Cu, Zn, Se, Mo, Ag, Cd, Sb, Ba, Tl, Pb, and U) in the Douro River estuary. For that, three matrices were collected (water, sediments and native local flora) to assess the extent of contamination by these elements in this estuarine ecosystem. Results showed their occurrence in estuarine water and sediments, but significant differences were recorded on the concentration levels and pattern of distribution among both matrices and sampling points. Generally, the levels of trace elements were higher in the sediments than in the respective estuarine water. Nonetheless, no correlation among trace elements was determined between water and sediments, except for Cd. Al was the trace element found at highest concentration at both sediments and water followed by Zn. Pollution indices such as geo-accumulation (I geo ), enrichment factor (EF) and contamination factor (CF) were determined to understand the levels and sources of trace elements pollution. I geo showed strong contamination by anthropogenic activities for Li, Al, V, Cr, Ni, Cu, Zn, Ba and Pb at all sampling points while EF and CF demonstrated severe enrichment and contamination by Se, Sb and Pb. Levels of trace elements were compared to acceptable values for aquatic organisms and Sediment Quality Guidelines. The concentration of some trace elements, namely Al, Pb and Cu, were higher than those considered acceptable, with potential negative impact on local living organisms. Nevertheless, permissible values for all trace elements are still not available, demonstrating that further studies are needed in order to have a complete assessment of environmental risk. Furthermore, the occurrence and possible accumulation of trace elements by local plant species and macroalgae were investigated as well as their potential use as bioindicators of local pollution and for phytoremediation purposes. Copyright © 2018 Elsevier B.V. All rights reserved.

Extended spider cognition.

PubMed

Japyassú, Hilton F; Laland, Kevin N

2017-05-01

There is a tension between the conception of cognition as a central nervous system (CNS) process and a view of cognition as extending towards the body or the contiguous environment. The centralised conception requires large or complex nervous systems to cope with complex environments. Conversely, the extended conception involves the outsourcing of information processing to the body or environment, thus making fewer demands on the processing power of the CNS. The evolution of extended cognition should be particularly favoured among small, generalist predators such as spiders, and here, we review the literature to evaluate the fit of empirical data with these contrasting models of cognition. Spiders do not seem to be cognitively limited, displaying a large diversity of learning processes, from habituation to contextual learning, including a sense of numerosity. To tease apart the central from the extended cognition, we apply the mutual manipulability criterion, testing the existence of reciprocal causal links between the putative elements of the system. We conclude that the web threads and configurations are integral parts of the cognitive systems. The extension of cognition to the web helps to explain some puzzling features of spider behaviour and seems to promote evolvability within the group, enhancing innovation through cognitive connectivity to variable habitat features. Graded changes in relative brain size could also be explained by outsourcing information processing to environmental features. More generally, niche-constructed structures emerge as prime candidates for extending animal cognition, generating the selective pressures that help to shape the evolving cognitive system.

Uncovering changes in spider orb-web topology owing to aerodynamic effects

PubMed Central

Zaera, Ramón; Soler, Alejandro; Teus, Jaime

2014-01-01

An orb-weaving spider's likelihood of survival is influenced by its ability to retain prey with minimum damage to its web and at the lowest manufacturing cost. This set of requirements has forced the spider silk to evolve towards extreme strength and ductility to a degree that is rare among materials. Previous studies reveal that the performance of the web upon impact may not be based on the mechanical properties of silk alone, aerodynamic drag could play a role in the dissipation of the prey's energy. Here, we present a thorough analysis of the effect of the aerodynamic drag on wind load and prey impact. The hypothesis considered by previous authors for the evaluation of the drag force per unit length of thread has been revisited according to well-established principles of fluid mechanics, highlighting the functional dependence on thread diameter that was formerly ignored. Theoretical analysis and finite-element simulations permitted us to identify air drag as a relevant factor in reducing deterioration of the orb web, and to reveal how the spider can take greater—and not negligible—advantage of drag dissipation. The study shows the beneficial air drag effects of building smaller and less dense webs under wind load, and larger and denser webs under prey impact loads. In essence, it points out why the aerodynamics need to be considered as an additional driving force in the evolution of silk threads and orb webs. PMID:24966235

Uncovering changes in spider orb-web topology owing to aerodynamic effects.

PubMed

Zaera, Ramón; Soler, Alejandro; Teus, Jaime

2014-09-06

An orb-weaving spider's likelihood of survival is influenced by its ability to retain prey with minimum damage to its web and at the lowest manufacturing cost. This set of requirements has forced the spider silk to evolve towards extreme strength and ductility to a degree that is rare among materials. Previous studies reveal that the performance of the web upon impact may not be based on the mechanical properties of silk alone, aerodynamic drag could play a role in the dissipation of the prey's energy. Here, we present a thorough analysis of the effect of the aerodynamic drag on wind load and prey impact. The hypothesis considered by previous authors for the evaluation of the drag force per unit length of thread has been revisited according to well-established principles of fluid mechanics, highlighting the functional dependence on thread diameter that was formerly ignored. Theoretical analysis and finite-element simulations permitted us to identify air drag as a relevant factor in reducing deterioration of the orb web, and to reveal how the spider can take greater-and not negligible-advantage of drag dissipation. The study shows the beneficial air drag effects of building smaller and less dense webs under wind load, and larger and denser webs under prey impact loads. In essence, it points out why the aerodynamics need to be considered as an additional driving force in the evolution of silk threads and orb webs. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Predator-induced flow disturbances alert prey, from the onset of an attack

PubMed Central

Casas, Jérôme; Steinmann, Thomas

2014-01-01

Many prey species, from soil arthropods to fish, perceive the approach of predators, allowing them to escape just in time. Thus, prey capture is as important to predators as prey finding. We extend an existing framework for understanding the conjoint trajectories of predator and prey after encounters, by estimating the ratio of predator attack and prey danger perception distances, and apply it to wolf spiders attacking wood crickets. Disturbances to air flow upstream from running spiders, which are sensed by crickets, were assessed by computational fluid dynamics with the finite-elements method for a much simplified spider model: body size, speed and ground effect were all required to obtain a faithful representation of the aerodynamic signature of the spider, with the legs making only a minor contribution. The relationship between attack speed and the maximal distance at which the cricket can perceive the danger is parabolic; it splits the space defined by these two variables into regions differing in their values for this ratio. For this biological interaction, the ratio is no greater than one, implying immediate perception of the danger, from the onset of attack. Particular attention should be paid to the ecomechanical aspects of interactions with such small ratio, because of the high degree of bidirectional coupling of the behaviour of the two protagonists. This conclusion applies to several other predator–prey systems with sensory ecologies based on flow sensing, in air and water. PMID:25030986

Assessment of serum trace elements and electrolytes in children with childhood and atypical autism.

PubMed

Skalny, Anatoly V; Simashkova, Natalia V; Klyushnik, Tatiana P; Grabeklis, Andrei R; Radysh, Ivan V; Skalnaya, Margarita G; Nikonorov, Alexandr A; Tinkov, Alexey A

2017-09-01

The existing data demonstrate a significant interrelation between ASD and essential and toxic trace elements status of the organism. However, data on trace element homeostasis in particular ASD forms are insufficient. Therefore, the objective of the present study was to assess the level of trace elements and electrolytes in serum of children with childhood and atypical autism. A total of 48 children with ASD (24 with childhood and 24 with atypical autism) and age- and sex-adjusted controls were examined. Serum trace elements and electrolytes were assessed using inductively-coupled plasma mass spectrometry. The obtained data demonstrate that children with ASD unspecified are characterized by significantly lower Ni, Cr, and Se levels as compared to the age- and sex-matched controls. At the same time, significantly decreased serum Ni and Se concentrations were detected in patients with childhood autism. In turn, children with atypical autism were characterized by more variable serum trace element spectrum. In particular, atypical autism is associated with lower serum Al, As, Ni, Cr, Mn, and Se levels in comparison to the control values. Moreover, Al and Mn concentration in this group was also lower than that in childhood autism patients. Generally, the obtained data demonstrate lower levels of both essential and toxic trace elements in atypical autism group, being indicative of profound alteration of trace elements metabolism. However, further detailed metabolic studies are required to reveal critical differences in metabolic pathways being responsible for difference in trace element status and clinical course of the disease. Copyright © 2016 Elsevier GmbH. All rights reserved.

[Determination of Trace Elements in Marine Cetaceans by ICP-MS and Health Risk Assessment].

PubMed

Ding, Yu-long; Ning, Xi; Gui, Duan; Mo, Hui; Li, Yu-sen; Wu, Yu-ping

2015-09-01

The liver, kidney and muscle samples from seven cetaceans were digested by microwave digestion, and trace elements amounts of V, Cd, Cu, Zn, As, Cr, Ni, Mn, Se, Hg and Pb were determined by inductively coupled plasma mass spectrometry (ICP-MS), and the health risk assessment for Zn, Cu, Cd, Hg, Se in the liver was conducted. The results of international lobster hepatopancreas standard (TORT-2) showed acceptable agreement with the certified values, and the relative standard deviation (RSD) of eleven kinds of trace elements were less than 3.54%, showing that the method is suitable for the determination of trace elements in cetaceans. The experimental results indicated that different tissues and organs of the dolphins had different trace elements, presenting the tissue specificity. There is a certain inter-species difference among different dolphins about the bioaccumulation ability of the trace elements. The distribution of trace elements in whales presented a certain regularity: the contents of most elements in liver, kidney were much higher than the contents of muscle tissues, Cu, Mn, Hg, Se, and Zn exhibit the higher concentrations in liver, while Cd was mainly accumulated in kidney. And according to the health risk assessment in liver, the exceeding standardrate of selenium and copper in seven kinds of whales was 100%, suggesting that these whales were suffering the contamination of trace elements. The experimental results is instructive to the study of trace elements in cetaceans, while this is the first report for the concentrations in organs of Striped dolphin, Bottlenose dolphin, Fraser's Dolphin and Risso's dolphin in China, it may provide us valuable data for the conservation of cetaceans.

Selected elements in major minerals from bituminous coal as determined by INAA: Implications for removing environmentally sensitive elements from coal

USGS Publications Warehouse

Palmer, C.A.; Lyons, P.C.

1996-01-01

The four most abundant minerals generally found in Euramerican bituminous coals are quartz, kaolinite, illite and pyrite. These four minerals were isolated by density separation and handpicking from bituminous coal samples collected in the Ruhr Basin, Germany and the Appalachian basin, U.S.A. Trace-element concentrations of relatively pure (??? 99+%) separates of major minerals from these coals were determined directly by using instrumental neutron activation analysis (INAA). As expected, quartz contributes little to the trace-element mass balance. Illite generally has higher trace-element concentrations than kaolinite, but, for the concentrates analyzed in this study, Hf, Ta, W, Th and U are in lower concentrations in illite than in kaolinite. Pyrite has higher concentrations of chalcophile elements (e.g., As and Se) and is considerably lower in lithophile elements as compared to kaolinite and illite. Our study provides a direct and sensitive method of determining trace-element relationships with minerals in coal. Mass-balance calculations suggest that the trace-element content of coal can be explained mainly by three major minerals: pyrite, kaolinite and illite. This conclusion indicates that the size and textural relationships of these major coal minerals may be a more important consideration as to whether coal cleaning can effectively remove the most environmentally sensitive trace elements in coal than what trace minerals are present.

Origin and distribution of trace elements in high-elevation precipitation in southern China.

PubMed

Zhou, Jie; Wang, Yan; Yue, Taixing; Li, Yuhua; Wai, Ka-Ming; Wang, Wenxing

2012-09-01

During a 2009 investigation of the transport and deposition of trace elements in southern China, 37 event-based precipitation samples were collected at an observatory on Mount Heng, China (1,269 m asl). Concentrations of trace elements were analyzed using inductively coupled plasma-mass spectrometry and the wet deposition fluxes were established. A combination of techniques including enrichment factor analysis, principal component analysis, and back trajectory models were used to identify pollutant sources. Trace element concentrations at Mount Heng were among the highest with respect to measured values reported elsewhere. All elements were of non-marine origin. The elements Pb, As, Cu, Se, and Cd were anthropogenic, while Fe, Cr, V, Ba, Mn, and Ni were of mixed crustal/anthropogenic origin. The crustal and anthropogenic contributions of trace elements were 12.8 % (0.9 ~ 17.4 %) and 87.2 % (82.6 ~ 99.1 %), with the maximum crustal fraction being 17.4 % for Fe. Coal combustion, soil and road dust, metallurgical processes, and industrial activities contributed to the element composition. Summit precipitation events were primarily distant in origin. Medium- to long-range transport of trace elements from the Yangtze River Delta and northern China played an important role in wet deposition at Mount Heng, while air masses from south or southeast of the station were generally low in trace element concentrations.

Trends in Trace Element Fractionation Between Foraminiferal Species and the Role of Biomineralization

NASA Astrophysics Data System (ADS)

Reichart, G. J.; Nooijer, L. D.; Geerken, E.; Mezger, E.; van Dijk, I. V.; Daemmer, L. K.

2017-12-01

Reconstructions of past climate and environments are largely based on stable isotopes and trace element concentrations measured on fossil foraminiferal calcite. Their element and isotope composition roughly reflects seawater composition and physical conditions, which in turn, are related to paleoceanographic parameters. More recently, attempts are being made to infer ranges in environmental parameters using the observed differences in the composition within individual tests. Remarkably, inter-species differences in trace element incorporation are well-correlated over a wide range of environmental conditions. This is particularly remarkable knowing that different environmental factors influence incorporation of these elements at various magnitudes. Most likely the complex biomineralization of foraminifera potentially offsets trace elements similarly at all these scales and also between different species. This suggests that at least parts of the mechanisms underlying foraminiferal biomineralization are similar for all species, which in turn provides important clues on the cellular mechanisms operating during calcification. Moreover, the systematics in trace element partitioning between species could potentially provide important clues for unravelling past changes in trace element composition of the ancient ocean.

Molecular phylogeny of moth-specialized spider sub-family Cyrtarachninae, which includes bolas spiders.

PubMed

Tanikawa, Akio; Shinkai, Akira; Miyashita, Tadashi

2014-11-01

The evolutionary process of the unique web architectures of spiders of the sub-family Cyrtarachninae, which includes the triangular web weaver, bolas spider, and webless spider, is thought to be derived from reduction of orbicular 'spanning-thread webs' resembling ordinal orb webs. A molecular phylogenetic analysis was conducted to explore this hypothesis using orbicular web spiders Cyrtarachne, Paraplectana, Poecilopachys, triangular web spider Pasilobus, bolas spiders Ordgarius and Mastophora, and webless spider Celaenia. The phylogeny inferred from partial sequences of mt-COI, nuclear 18S-rRNA and 28S-rRNA showed that the common ancestor of these spiders diverged into two clades: a spanning-thread web clade and a bolas or webless clade. This finding suggests that the triangular web evolved by reduction of an orbicular spanning web, but that bolas spiders evolved in the early stage, which does not support the gradual web reduction hypothesis.

Phylogenomics resolves a spider backbone phylogeny and rejects a prevailing paradigm for orb web evolution.

PubMed

Bond, Jason E; Garrison, Nicole L; Hamilton, Chris A; Godwin, Rebecca L; Hedin, Marshal; Agnarsson, Ingi

2014-08-04

Spiders represent an ancient predatory lineage known for their extraordinary biomaterials, including venoms and silks. These adaptations make spiders key arthropod predators in most terrestrial ecosystems. Despite ecological, biomedical, and biomaterial importance, relationships among major spider lineages remain unresolved or poorly supported. Current working hypotheses for a spider "backbone" phylogeny are largely based on morphological evidence, as most molecular markers currently employed are generally inadequate for resolving deeper-level relationships. We present here a phylogenomic analysis of spiders including taxa representing all major spider lineages. Our robust phylogenetic hypothesis recovers some fundamental and uncontroversial spider clades, but rejects the prevailing paradigm of a monophyletic Orbiculariae, the most diverse lineage, containing orb-weaving spiders. Based on our results, the orb web either evolved much earlier than previously hypothesized and is ancestral for a majority of spiders or else it has multiple independent origins, as hypothesized by precladistic authors. Cribellate deinopoid orb weavers that use mechanically adhesive silk are more closely related to a diverse clade of mostly webless spiders than to the araneoid orb-weaving spiders that use adhesive droplet silks. The fundamental shift in our understanding of spider phylogeny proposed here has broad implications for interpreting the evolution of spiders, their remarkable biomaterials, and a key extended phenotype--the spider web. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spiders (Araneae) Found in Bananas and Other International Cargo Submitted to North American Arachnologists for Identification.

PubMed

Vetter, Richard S; Crawford, Rodney L; Buckle, Donald J

2014-11-01

Spiders found in international cargo brought into North America are sometimes submitted to arachnologists for identification. Often, these spiders are presumed to be of medical importance because of size or a submitter's familiarity with a toxic spider genus from the continent of origin. Starting in 2006, requests were made for spiders found in international cargo brought into North America, in addition to the specimens from similar cargo shipments already in our museum collections. This was an ad hoc study that allowed us to focus on spiders of concern to the discoverer. We identified 135 spiders found in international cargo. A key for the most common species is provided. The most frequently submitted spiders were the pantropical huntsman spider, Heteropoda venatoria (L.) (Sparassidae), and the redfaced banana spider, Cupiennius chiapanensis Medina Soriano (Ctenidae). Spiders of medical importance were rare. The most common cargo from which spiders were submitted was bananas with most specimens coming from Central America, Ecuador, or Colombia. Lack of experience with nonnative fauna caused several experienced American arachnologists to misidentify harmless ctenid spiders (C. chiapanensis, spotlegged banana spider, Cupiennius getazi Simon) as highly toxic Phoneutria spiders. These misidentifications could have led to costly, unwarranted prophylactic eradication measures, unnecessary employee health education, heightened employee anxiety and spoilage when perishable goods are left unloaded due to safety concerns. © 2014 Entomological Society of America.

Spiders (Araneae) of Churchill, Manitoba: DNA barcodes and morphology reveal high species diversity and new Canadian records

PubMed Central

2013-01-01

Background Arctic ecosystems, especially those near transition zones, are expected to be strongly impacted by climate change. Because it is positioned on the ecotone between tundra and boreal forest, the Churchill area is a strategic locality for the analysis of shifts in faunal composition. This fact has motivated the effort to develop a comprehensive biodiversity inventory for the Churchill region by coupling DNA barcoding with morphological studies. The present study represents one element of this effort; it focuses on analysis of the spider fauna at Churchill. Results 198 species were detected among 2704 spiders analyzed, tripling the count for the Churchill region. Estimates of overall diversity suggest that another 10–20 species await detection. Most species displayed little intraspecific sequence variation (maximum <1%) in the barcode region of the cytochrome c oxidase subunit I (COI) gene, but four species showed considerably higher values (maximum = 4.1-6.2%), suggesting cryptic species. All recognized species possessed a distinct haplotype array at COI with nearest-neighbour interspecific distances averaging 8.57%. Three species new to Canada were detected: Robertus lyrifer (Theridiidae), Baryphyma trifrons (Linyphiidae), and Satilatlas monticola (Linyphiidae). The first two species may represent human-mediated introductions linked to the port in Churchill, but the other species represents a range extension from the USA. The first description of the female of S. monticola was also presented. As well, one probable new species of Alopecosa (Lycosidae) was recognized. Conclusions This study provides the first comprehensive DNA barcode reference library for the spider fauna of any region. Few cryptic species of spiders were detected, a result contrasting with the prevalence of undescribed species in several other terrestrial arthropod groups at Churchill. Because most (97.5%) sequence clusters at COI corresponded with a named taxon, DNA barcoding reliably identifies spiders in the Churchill fauna. The capacity of DNA barcoding to enable the identification of otherwise taxonomically ambiguous specimens (juveniles, females) also represents a major advance for future monitoring efforts on this group. PMID:24279427

Responses of trace elements to aerobic maximal exercise in elite sportsmen.

PubMed

Otag, Aynur; Hazar, Muhsin; Otag, Ilhan; Gürkan, Alper Cenk; Okan, Ilyas

2014-02-21

Trace elements are chemical elements needed in minute quantities for the proper growth, development, and physiology of the organism. In biochemistry, a trace element is also referred to as a micronutrient. Trace elements, such as nickel, cadmium, aluminum, silver, chromium, molybdenum, germanium, tin, titanium, tungsten, scandium, are found naturally in the environment and human exposure derives from a variety of sources, including air, drinking water and food. The Purpose of this study was investigated the effect of aerobic maximal intensity endurance exercise on serum trace elements as well-trained individuals of 28 wrestlers (age (year) 19.64±1.13, weight (Kg) 70.07 ± 15.69, height (cm) 176.97 ± 6.69) during and after a 2000 meter Ergometer test protocol was used to perform aerobic (75 %) maximal endurance exercise. Trace element serum levels were analyzed from blood samples taken before, immediately after and one hour after the exercise. While an increase was detected in Chromium (Cr), Nickel (Ni), Molybdenum (Mo) and Titanium (Ti) serum levels immediately after the exercise, a decrease was detected in Aluminum (Al), Scandium (Sc) and Tungsten (W) serum levels. Except for aluminum, the trace elements we worked on showed statistically meaningful responses (P < 0.05 and P < 0.001). According to the responses of trace elements to the exercise showed us the selection and application of the convenient sport is important not only in terms of sportsman performance but also in terms of future healthy life plans and clinically.

Fear and Disgust of Spiders: Factors that Limit University Preservice Middle School Science Teachers

PubMed Central

Wagler, Ron; Wagler, Amy

2018-01-01

Spiders perform many essential ecological services, yet humans often experience negative emotions toward spiders. These emotions can lead to the avoidance of beneficial events. These emotions may affect beliefs about what should or should not be included in a science curriculum. This study investigated how activities with living spiders affected preservice middle school science teachers’ emotions and beliefs. Prior to the activities both groups (i.e., treatment and control) had moderate to extreme fear and disgust toward the spider. The teachers that participated in the spider activities (i.e., treatment group) had much lower levels of fear and disgust after performing the spider activities than the control group that did not participate in the spider activities. The control group continued to have elevated levels of fear and disgust toward the spider throughout the study. Before the spider activities neither group planned to incorporate information about spiders or information about the essential ecological services of spiders into their science classroom. After the treatment group participated in the spider activities, the teachers had definitive plans to teach their students about spiders and the essential ecological services that they provide. The control group remained unchanged and had no plans to teach this information to their students. PMID:29382186

Fear and Disgust of Spiders: Factors that Limit University Preservice Middle School Science Teachers.

PubMed

Wagler, Ron; Wagler, Amy

2018-01-29

Spiders perform many essential ecological services, yet humans often experience negative emotions toward spiders. These emotions can lead to the avoidance of beneficial events. These emotions may affect beliefs about what should or should not be included in a science curriculum. This study investigated how activities with living spiders affected preservice middle school science teachers' emotions and beliefs. Prior to the activities both groups (i.e., treatment and control) had moderate to extreme fear and disgust toward the spider. The teachers that participated in the spider activities (i.e., treatment group) had much lower levels of fear and disgust after performing the spider activities than the control group that did not participate in the spider activities. The control group continued to have elevated levels of fear and disgust toward the spider throughout the study. Before the spider activities neither group planned to incorporate information about spiders or information about the essential ecological services of spiders into their science classroom. After the treatment group participated in the spider activities, the teachers had definitive plans to teach their students about spiders and the essential ecological services that they provide. The control group remained unchanged and had no plans to teach this information to their students.

Assessing the risks of trace elements in environmental materials under selected greenhouse vegetable production systems of China.

PubMed

Chen, Yong; Huang, Biao; Hu, Wenyou; Weindorf, David C; Liu, Xiaoxiao; Niedermann, Silvana

2014-02-01

The risk assessment of trace elements of different environmental media in conventional and organic greenhouse vegetable production systems (CGVPS and OGVPS) can reveal the influence of different farming philosophy on the trace element accumulations and their effects on human health. These provide important basic data for the environmental protection and human health. This paper presents trace element accumulation characteristics of different land uses; reveals the difference of soil trace element accumulation both with and without consideration of background levels; compares the trace element uptake by main vegetables; and assesses the trace element risks of soils, vegetables, waters and agricultural inputs, using two selected greenhouse vegetable systems in Nanjing, China as examples. Results showed that greenhouse vegetable fields contained significant accumulations of Zn in CGVPS relative to rice-wheat rotation fields, open vegetable fields, and geochemical background levels, and this was the case for organic matter in OGVPS. The comparative analysis of the soil medium in two systems with consideration of geochemical background levels and evaluation of the geo-accumulation pollution index achieved a more reasonable comparison and accurate assessment relative to the direct comparison analysis and the evaluation of the Nemerow pollution index, respectively. According to the Chinese food safety standards and the value of the target hazard quotient or hazard index, trace element contents of vegetables were safe for local residents in both systems. However, the spatial distribution of the estimated hazard index for producers still presented certain specific hotspots which may cause potential risk for human health in CGVPS. The water was mainly influenced by nitrogen, especially for CGVPS, while the potential risk of Cd and Cu pollution came from sediments in OGVPS. The main inputs for trace elements were fertilizers which were relatively safe based on relevant standards; but excess application caused trace element accumulations in the environmental media. Copyright © 2013 Elsevier B.V. All rights reserved.

The role of fear and expectancies in capture of covert attention by spiders.

PubMed

Devue, Christel; Belopolsky, Artem V; Theeuwes, Jan

2011-08-01

Fear-related stimuli are often prioritized during visual selection but it remains unclear whether capture by salient objects is more likely to occur when individuals fear those objects. In this study, participants with high and low fear of spiders searched for a circle while on some trials a completely irrelevant fear-related (spider) or neutral distractor (butterfly/leaf) was presented simultaneously in the display. Our results show that when you fear spiders and you are not sure whether a spider is going to be present, then any salient distractor (i.e., a butterfly) grabs your attention, suggesting that mere expectation of a spider triggered compulsory monitoring of all irrelevant stimuli. However, neutral stimuli did not grab attention when high spider fearful people knew that a spider could not be present during a block of trials, treating the neutral stimuli just as the low spider fearful people do. Our results show that people that fear spiders inspect potential spider-containing locations in a compulsory fashion even though directing attention to this location is completely irrelevant for the task. Reduction of capture can only be accomplished when people that fear spiders do not expect a spider to be present. 2011 APA, all rights reserved

Trace elements in natural azurite pigments found in illuminated manuscript leaves investigated by synchrotron x-ray fluorescence and diffraction mapping

NASA Astrophysics Data System (ADS)

Smieska, Louisa M.; Mullett, Ruth; Ferri, Laurent; Woll, Arthur R.

2017-07-01

We present trace-element and composition analysis of azurite pigments in six illuminated manuscript leaves, dating from the thirteenth to sixteenth century, using synchrotron-based, large-area x-ray fluorescence (SR-XRF) and diffraction (SR-XRD) mapping. SR-XRF mapping reveals several trace elements correlated with azurite, including arsenic, zirconium, antimony, barium, and bismuth, that appear in multiple manuscripts but were not always detected by point XRF. Within some manuscript leaves, variations in the concentration of trace elements associated with azurite coincide with distinct regions of the illuminations, suggesting systematic differences in azurite preparation or purification. Variations of the trace element concentrations in azurite are greater among different manuscript leaves than the variations within each individual leaf, suggesting the possibility that such impurities reflect distinct mineralogical/geologic sources. SR-XRD maps collected simultaneously with the SR-XRF maps confirm the identification of azurite regions and are consistent with impurities found in natural mineral sources of azurite. In general, our results suggest the feasibility of using azurite trace element analysis for provenance studies of illuminated manuscript fragments, and demonstrate the value of XRF mapping in non-destructive determination of trace element concentrations within a single pigment.

Co-digestion of manure and industrial waste--The effects of trace element addition.

PubMed

Nordell, Erik; Nilsson, Britt; Nilsson Påledal, Sören; Karisalmi, Kaisa; Moestedt, Jan

2016-01-01

Manure is one of the most common substrates for biogas production. Manure from dairy- and swine animals are often considered to stabilize the biogas process by contributing nutrients and trace elements needed for the biogas process. In this study two lab-scale reactors were used to evaluate the effects of trace element addition during co-digestion of manure from swine- and dairy animals with industrial waste. The substrate used contained high background concentrations of both cobalt and nickel, which are considered to be the most important trace elements. In the reactor receiving additional trace elements, the volatile fatty acids (VFA) concentration was 89% lower than in the control reactor. The lower VFA concentration contributed to a more digested digestate, and thus lower methane emissions in the subsequent storage. Also, the biogas production rate increased with 24% and the biogas production yield with 10%, both as a result of the additional trace elements at high organic loading rates. All in all, even though 50% of the feedstock consisted of manure, trace element addition resulted in multiple positive effects and a more reliable process with stable and high yield. Copyright © 2015 Elsevier Ltd. All rights reserved.

Trace elements in dialysis.

PubMed

Filler, Guido; Felder, Sarah

2014-08-01

In end-stage chronic kidney disease (CKD), pediatric nephrologists must consider the homeostasis of the multiple water-soluble ions that are influenced by renal replacement therapy (RRT). While certain ions such as potassium and calcium are closely monitored, little is known about the handling of trace elements in pediatric dialysis. RRT may lead to accumulation of toxic trace elements, either due to insufficient elimination or due to contamination, or to excessive removal of essential trace elements. However, trace elements are not routinely monitored in dialysis patients and no mechanism for these deficits or toxicities has been established. This review summarizes the handling of trace elements, with particular attention to pediatric data. The best data describe lead and indicate that there is a higher prevalence of elevated lead (Pb, atomic number 82) levels in children on RRT when compared to adults. Lead is particularly toxic in neurodevelopment and lead levels should therefore be monitored. Monitoring of zinc (Zn, atomic number 30) and selenium (Se, atomic number 34) may be indicated in the monitoring of all pediatric dialysis patients to reduce morbidity from deficiency. Prospective studies evaluating the impact of abnormal trace elements and the possible therapeutic value of intervention are required.

Determination of trace elements and their concentrations in clay balls: problem of geophagia practice in Ghana.

PubMed

Arhin, Emmanuel; Zango, Musah S

2017-02-01

Ten samples of 100 g weight were subsampled from 1400 g of the clay balls from which the contained trace element levels were determined by X-ray fluorescence technique. The results of trace elements in the clay balls were calibrated using certified reference materials "MAJMON" and "BH-1." The results showed elevated concentrations but with different concentration levels in the regions, particularly with arsenic, chromium, cobalt, Cs, Zr and La. These trace elements contained in the clay balls are known to be hazardous to human health. Thence the relatively high concentrations of these listed trace elements in clay balls in the three regions, namely Ashanti, Upper East and Volta, which are widely sold in markets in Ghana, could present negative health impact on consumers if consumed at 70 g per day or more and on regular basis. On the basis of these, the study concludes an investigation to establish breakeven range for trace element concentrations in the clay balls as it has been able to demonstrate the uneven and elevated values in them. The standardized safe ranges of trace elements will make the practice safer for the people that ingest clay balls in Ghana.

Trace-element concentrations in streambed sediment across the conterminous United States

USGS Publications Warehouse

Rice, Karen C.

1999-01-01

Trace-element concentrations in 541 streambed-sediment samples collected from 20 study areas across the conterminous United States were examined as part of the National Water-Quality Assessment Program of the U.S. Geological Survey. Sediment samples were sieved and the <63-μm fraction was retained for determination of total concentrations of trace elements. Aluminum, iron, titanium, and organic carbon were weakly or not at all correlated with the nine trace elements examined:  arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc. Four different methods of accounting for background/baseline concentrations were examined; however, normalization was not required because field sieving removed most of the background differences between samples. The sum of concentrations of trace elements characteristic of urban settings - copper, mercury, lead, and zinc - was well correlated with population density, nationwide. Median concentrations of seven trace elements (all nine examined except arsenic and selenium) were enriched in samples collected from urban settings relative to agricultural or forested settings. Forty-nine percent of the sites sampled in urban settings had concentrations of one or more trace elements that exceeded levels at which adverse biological effects could occur in aquatic biota.

Soluble trace elements and total mercury in Arctic Alaskan snow

USGS Publications Warehouse

Snyder-Conn, E.; Garbarino, J.R.; Hoffman, G.L.; Oelkers, A.

1997-01-01

Ultraclean field and laboratory procedures were used to examine trace element concentrations in northern Alaskan snow. Sixteen soluble trace elements and total mercury were determined in snow core samples representing the annual snowfall deposited during the 1993-94 season at two sites in the Prudhoe Bay oil field and nine sites in the Arctic National Wildlife Refuge (Arctic NWR). Results indicate there were two distinct point sources for trace elements in the Prudhoe Bay oil field - a source associated with oil and gas production and a source associated with municipal solid-waste incineration. Soluble trace element concentrations measured in snow from the Arctic NWR resembled concentrations of trace elements measured elsewhere in the Arctic using clean sample-collection and processing techniques and were consistent with deposition resulting from widespread arctic atmospheric contamination. With the exception of elements associated with sea salts, there were no orographic or east-west trends observed in the Arctic NWR data, nor were there any detectable influences from the Prudhoe Bay oil field, probably because of the predominant easterly and northeasterly winds on the North Slope of Alaska. However, regression analysis on latitude suggested significant south-to-north increases in selected trace element concentrations, many of which appear unrelated to the sea salt contribution.

The effects of trace element content on pyrite oxidation rates

NASA Astrophysics Data System (ADS)

Gregory, D. D.; Lyons, T.; Cliff, J. B.; Perea, D. E.; Johnson, A.; Romaniello, S. J.; Large, R. R.

2017-12-01

Pyrite acts as both an important source and sink for many different metals and metalloids in the environment, including many that are toxic. Oxidation of pyrite can release these elements while at the same time producing significant amounts of sulfuric acid. Such issues are common in the vicinity of abandoned mines and smelters, but, as pyrite is a common accessory mineral in many different lithologies, significant pyrite oxidation can occur whenever pyritic rocks are exposed to oxygenated water or the atmosphere. Accelerated exposure to oxygen can occur during deforestation, fracking for petroleum, and construction projects. Geochemical models for pyrite oxidation can help us develop strategies to mitigate these deleterious effects. An important component of these models is an accurate pyrite oxidation rate; however, current pyrite oxidation rates have been determined using relatively pure pyrite. Natural pyrite is rarely pure and has a wide range of trace element concentrations that may affect the oxidation rate. Furthermore, the position of trace elements within the mineral lattice can also affect the oxidation rate. For example, elements such as Ni and Co, which substitute into the pyrite lattice, are thought to stabilize the lattice and thus prevent pyrite oxidation. Alternatively, trace elements that are held within inclusions of other minerals could form a galvanic cell with the surrounding pyrite, thus enhancing pyrite oxidation rates. In this study, we present preliminary analyses from three different pyrite oxidation experiments each using natural pyrite with different trace element compositions. These results show that the pyrite with the highest trace element concentration has approximately an order of magnitude higher oxidation rate compared to the lowest trace element sample. To further elucidate the mechanisms, we employed microanalytical techniques to investigate how the trace elements are held within the pyrite. LA-ICPMS was used to determine the variability of trace element content from the pyrite samples. These data were then used to select areas of interest for NanoSIMS analyses, which in turn was used to select areas for TEM and APT. These analyses show that the trace element content of pyrite can be highly variable, which may significantly affect the rate of pyrite oxidation.

Concentrations of selected trace elements in fish tissue and streambed sediment in the Clark Fork-Pend Oreille and Spokane River basins, Washington, Idaho, and Montana, 1998

USGS Publications Warehouse

Maret, Terry R.; Skinner, K.D.

2000-01-01

Fish tissue and bed sediment samples were collected from 16 stream sites in the Northern Rockies Intermontane Basins study area in 1998 as part of the U.S. Geological Survey National Water-Quality Assessment Program. Bed sediment samples were analyzed for 45 trace elements, and fish livers and sportfish fillets were analyzed for 22 elements to characterize the occurrence and distribution of these elements in relation to stream characteristics and land use activities. Nine trace elements of environmental concern—arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc—were detected in bed sediment, but not all of these elements were detected in fish tissue. Trace-element concentrations were highest in bed sediment samples collected at sites downstream from significant natural mineral deposits and (or) mining activities. Arsenic, cadmium, copper, lead, mercury, and zinc in bed sediment at some sites were elevated relative to national median concentrations, and some concentrations were at levels that can adversely affect aquatic biota. Although trace-element concentrations in bed sediment exceeded various guidelines, no concentrations in sportfish fillets exceeded U.S. Environmental Protection Agency screening values for the protection of human health. Correlations between most trace-element concentrations in bed sediment and fish tissue (liver and fillet) were not significant (r0.05). Concentrations of arsenic, cadmium, copper, lead, mercury, nickel, selenium, and zinc in bed sediment were significantly correlated (r=0.53 to 0.88, p2=0.95 and 0.99, p<0.001) that corresponded to trace-element enrichment categories. These strong relations warrant further study using mine density as an explanatory variable to predict trace-element concentrations in bed sediment.

Trace Elements in Marine Sediment and Organisms in the Gulf of Thailand

PubMed Central

Worakhunpiset, Suwalee

2018-01-01

This review summarizes the findings from studies of trace element levels in marine sediment and organisms in the Gulf of Thailand. Spatial and temporal variations in trace element concentrations were observed. Although trace element contamination levels were low, the increased urbanization and agricultural and industrial activities may adversely affect ecosystems and human health. The periodic monitoring of marine environments is recommended in order to minimize human health risks from the consumption of contaminated marine organisms. PMID:29677146

Verified spider bites in Oregon (USA) with the intent to assess hobo spider venom toxicity.

PubMed

McKeown, Nathanael; Vetter, Richard S; Hendrickson, Robert G

2014-06-01

This study compiled 33 verified spider bites from the state of Oregon (USA). The initial goal was to amass a series of bites by the hobo spider to assess whether it possesses toxic venom, a supposition which is currently in a contested state. None of the 33 bites from several spider species developed significant medical symptoms nor did dermonecrosis occur. The most common biters were the yellow sac spider, Cheiracanthium mildei (N = 10) and orb-weavers of the genus Araneus (N = 6). There were 10 bites from three genera of funnel web spiders of the family Agelenidae including one hobo spider bite and one from the congeneric giant house spider which is readily confused as a hobo spider. The hobo spider bite resulted in pain, redness, twitching in the calf muscle and resolved in 12 h. Also generated from this study were possibly the first records of bites from spiders of the genera Callobius (Amaurobiidae) and Antrodiaetus (Antrodiaetidae), both with minor manifestations. Published by Elsevier Ltd.

Differential accumulation of heavy metals by web spiders and ground spiders in an old-field

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

Larsen, K.J.; Brewer, S.R.; Taylor, D.H.

1994-03-01

Accumulation of the heavy metals Cd, Cu, Pb, and Zn by web spiders (orb weavers: Araneidae) and ground spiders was examined in an old-field that had been subjected to 11 years of nutrient enrichment. The study area consistent of six 0.1-ha plots treated from 1978 to 1988 with municipal sewage sludge containing heavy-metal contaminants, urea-phosphate fertilizer, or left as untreated controls. In 1991 and 1992, heavy-metal concentrations in the soil, ground spiders, and web spiders were measured with a flame AA spectrophotometer. Spiders accumulated Cd, Cu, and Zn to concentrations greater than those present in the soil but did notmore » accumulate Pb. Ground spiders contained significantly higher levels of Cd and Cu than web spiders, whereas web spiders contained slightly greater levels of Pb than ground spiders. No trend between spider guilds was apparent for Zn accumulation. To understand the impact of the application of metal-contaminated municipal sludge on ecosystem, the toxicological effects on the biology and behavior of major biotic components in terrestrial food webs must be known.« less

The significance of cutaneous spider naevi in children

PubMed Central

Finn, S M; Rowland, M; Lawlor, F; Kinsella, W; Chan, L; Byrne, O; O'Mahony, O; Bourke, B

2006-01-01

Background Cutaneous spider naevi are commonly considered to be a clinical sign of chronic liver disease. Little is known about their occurrence in children. Aim To evaluate the occurrence of spider naevi in children with and without liver disease. Methods The presence of spider naevi was investigated in 460 children, 34 of whom had chronic liver disease. Results Of children without liver involvement, 38% had at least one spider naevus. The prevalence of spider naevi increased with age. Of control patients aged 5 to 15 years, 2.5% had more than five spiders present. Although eight of 10 children with cirrhosis had at least one spider naevus, only four of 34 children with chronic liver disease had five or more spiders present. Most spiders were on the hands and very few were >5 mm in size. Conclusions Children with liver disease rarely have large numbers of spider naevi. Although the finding of five or more spider naevi is more common in liver disease, many normal children also have one or more of these lesions. PMID:16595646

LA-ICP-MS trace element mapping: insights into the crystallisation history of a metamorphic garnet population

NASA Astrophysics Data System (ADS)

George, Freya; Gaidies, Fred

2017-04-01

In comparison to our understanding of major element zoning, relatively little is known about the incorporation of trace elements into metamorphic garnet. Given their extremely slow diffusivities and sensitivity to changing mineral assemblages, the analysis of the distribution of trace elements in garnet has the potential to yield a wealth of information pertaining to interfacial attachment mechanisms during garnet crystallisation, the mobility of trace elements in both garnet and the matrix, and trace element geochronology. Due to advances in the spatial resolution and analytical precision of modern microbeam techniques, small-scale trace element variations can increasingly be documented and used to inform models of metamorphic crystallisation. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) in particular, can be used to rapidly quantify a wide range of elemental masses as a series of laser rasters, producing large volumes of spatially constrained trace element data. In this study, we present LA-ICP-MS maps of trace element concentrations from numerous centrally-sectioned garnets representative of the crystal size-distribution of a single sample's population. The study sample originates from the garnet-grade Barrovian zone of the Lesser Himalayan Sequence in Sikkim, northeast India, and has been shown to have crystallised garnet within a single assemblage between 515 ˚C and 565˚C, with no evidence for accessory phase reaction over the duration of garnet growth. Previous models have indicated that the duration of garnet crystallisation was extremely rapid (<1 Myr), with negligible diffusional homogenisation of major divalent cations. Consequently, the trace element record likely documents the primary zonation generated during garnet growth. In spite of straightforward (i.e. concentrically-zoned) major element garnet zonation, trace elements maps are characterised by significant complexity and variability. Y and the heavy rare earth elements are strongly enriched in crystal cores, where there is overprinting of the observed internal fabric, and exhibit numerous concentric annuli towards crystal rims. Conversely, the medium rare earth elements (e.g. Gd, Eu and Sm) exhibit bowl-shaped zoning from core to rim, with no annuli, and core and rim compositions of the medium rare earth elements are the same throughout the population within crystals of differing size. Cr exhibits pronounced spiral zoning, and the average Cr content increases towards garnet rims. In all cases, spirals are centered on the geometric core of the crystals. These LA-ICP-MS maps highlight the complexity of garnet growth over a single prograde event, and indicate that there is still much to be learnt from the analysis of garnet using ever-improving analytical methods. We explore the potential causes of the variations in the distribution of trace elements in garnet, and assess how these zoning patterns may be used to refine our understanding of the intricacies of garnet crystallisation and the spatial and temporal degree of trace element equilibration during metamorphism.

Trace elements in Mediterranean seagrasses and macroalgae. A review.

PubMed

Bonanno, Giuseppe; Orlando-Bonaca, Martina

2018-03-15

This review investigates the current state of knowledge on the levels of the main essential and non-essential trace elements in Mediterranean vascular plants and macroalgae. The research focuses also on the so far known effects of high element concentrations on these marine organisms. The possible use of plants and algae as bioindicators of marine pollution is discussed as well. The presence of trace elements is overall well known in all five Mediterranean vascular plants, whereas current studies investigated element concentrations in only c. 5.0% of all native Mediterranean macroalgae. Although seagrasses and macroalgae can generally accumulate and tolerate high concentrations of trace elements, phytotoxic levels are still not clearly identified for both groups of organisms. Moreover, although the high accumulation of trace elements in seagrasses and macroalgae is considered as a significant risk for the associated food webs, the real magnitude of this risk has not been adequately investigated yet. The current research provides enough scientific evidence that seagrasses and macroalgae may act as effective bioindicators, especially the former for trace elements in sediments, and the latter in seawater. The combined use of seagrasses and macroalgae as bioindicators still lacks validated protocols, whose application should be strongly encouraged to biomonitor exhaustively the presence of trace elements in the abiotic and biotic components of coastal ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

Visualizing trace element distribution in quartz using cathodoluminescence, electron microprobe, and laser ablation-inductively coupled plasma-mass spectrometry

USGS Publications Warehouse

Rusk, Brian; Koenig, Alan; Lowers, Heather

2011-01-01

Cathodoluminescent (CL) textures in quartz reveal successive histories of the physical and chemical fluctuations that accompany crystal growth. Such CL textures reflect trace element concentration variations that can be mapped by electron microprobe or laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Trace element maps in hydrothermal quartz from four different ore deposit types (Carlin-type Au, epithermal Ag, porphyry-Cu, and MVT Pb-Zn) reveal correlations among trace elements and between trace element concentrations and CL textures. The distributions of trace elements reflect variations in the physical and chemical conditions of quartz precipitation. These maps show that Al is the most abundant trace element in hydrothermal quartz. In crystals grown at temperatures below 300 °C, Al concentrations may vary by up to two orders of magnitude between adjacent growth zones, with no evidence for diffusion. The monovalent cations Li, Na, and K, where detectable, always correlate with Al, with Li being the most abundant of the three. In most samples, Al is more abundant than the combined total of the monovalent cations; however, in the MVT sample, molar Al/Li ratios are ~0.8. Antimony is present in concentrations up to ~120 ppm in epithermal quartz (~200–300 °C), but is not detectable in MVT, Carlin, or porphyry-Cu quartz. Concentrations of Sb do not correlate consistently with those of other trace elements or with CL textures. Titanium is only abundant enough to be mapped in quartz from porphyry-type ore deposits that precipitate at temperatures above ~400 °C. In such quartz, Ti concentration correlates positively with CL intensity, suggesting a causative relationship. In contrast, in quartz from other deposit types, there is no consistent correlation between concentrations of any trace element and CL intensity fluctuations.

Trace element profiles in modern horse molar enamel as tracers of seasonality: Evidence from micro-XRF, LA-ICP-MS and stable isotope analysis

NASA Astrophysics Data System (ADS)

de Winter, Niels; Goderis, Steven; van Malderen, Stijn; Vanhaecke, Frank; Claeys, Philippe

2016-04-01

A combination of laboratory micro-X-ray Fluorescence (μXRF) and stable carbon and oxygen isotope analysis shows that trace element profiles from modern horse molars reveal a seasonal pattern that co-varies with seasonality in the oxygen isotope records of enamel carbonate from the same teeth. A combination of six cheek teeth (premolars and molars) from the same individual yields a seasonal isotope and trace element record of approximately three years recorded during the growth of the molars. This record shows that reproducible measurements of various trace element ratios (e.g., Sr/Ca, Zn/Ca, Fe/Ca, K/Ca and S/Ca) lag the seasonal pattern in oxygen isotope records by 2-3 months. Laser Ablation-ICP-Mass Spectrometry (LA-ICP-MS) analysis on a cross-section of the first molar of the same individual is compared to the bench-top tube-excitation μXRF results to test the robustness of the measurements and to compare both methods. Furthermore, trace element (e.g. Sr, Zn, Mg & Ba) profiles perpendicular to the growth direction of the same tooth, as well as profiles parallel to the growth direction are measured with LA-ICP-MS and μXRF to study the internal distribution of trace element ratios in two dimensions. Results of this extensive complementary line-scanning procedure shows the robustness of state of the art laboratory micro-XRF scanning for the measurement of trace elements in bioapatite. The comparison highlights the advantages and disadvantages of both methods for trace element analysis and illustrates their complementarity. Results of internal variation within the teeth shed light on the origins of trace elements in mammal teeth and their potential use for paleo-environmental reconstruction.

Traffic-related trace elements in soils along six highway segments on the Tibetan Plateau: Influence factors and spatial variation.

PubMed

Wang, Guanxing; Zeng, Chen; Zhang, Fan; Zhang, Yili; Scott, Christopher A; Yan, Xuedong

2017-03-01

The accumulation of traffic-related trace elements in soil as the result of anthropogenic activities raises serious concerns about environmental pollution and public health. Traffic is the main source of trace elements in roadside soil on the Tibetan Plateau, an area otherwise devoid of industrial emissions. Indeed, the rapid development of tourism and transportation in this region means it is becoming increasingly important to identify the accumulation levels, influence distance, spatial distribution, and other relevant factors influencing trace elements. In this study, 229 soil samples along six segments of the major transportation routes on the Tibetan Plateau (highways G214, S308, and G109), were collected for analysis of eight trace elements (Cr, Co, Ni, As, Cu, Zn, Cd, and Pb). The results of statistical analyses showed that of the eight trace elements in soils, Cu, Zn, Cd, and Pb were primarily derived from traffic. The relationship between the trace element accumulation levels and the distance from the roadside followed an exponential decline, with the exception of Segment 3, the only unpaved gravel road studied. In addition, the distance of influence from the roadside varied by trace element and segment, ranging from 16m to 144m. Background values for each segment were different because of soil heterogeneity, while a number of other potential influencing factors (including traffic volume, road surface material, roadside distance, land cover, terrain, and altitude) all had significant effects on trace-element concentrations. Overall, however, concentrations along most of the road segments investigated were at, or below, levels defined as low on the Nemero Synthesis index. Copyright © 2017 Elsevier B.V. All rights reserved.

Evolution of trace elements in the planetary boundary layer in southern China: Effects of dust storms and aerosol-cloud interactions

NASA Astrophysics Data System (ADS)

Li, Tao; Wang, Yan; Zhou, Jie; Wang, Tao; Ding, Aijun; Nie, Wei; Xue, Likun; Wang, Xinfeng; Wang, Wenxing

2017-03-01

Aerosols and cloud water were analyzed at a mountaintop in the planetary boundary layer in southern China during March-May 2009, when two Asian dust storms occurred, to investigate the effects of aerosol-cloud interactions (ACIs) on chemical evolution of atmospheric trace elements. Fe, Al, and Zn predominated in both coarse and fine aerosols, followed by high concentrations of toxic Pb, As, and Cd. Most of these aerosol trace elements, which were affected by dust storms, exhibited various increases in concentrations but consistent decreases in solubility. Zn, Fe, Al, and Pb were the most abundant trace elements in cloud water. The trace element concentrations exhibited logarithmic inverse relationships with the cloud liquid water content and were found highly pH dependent with minimum concentrations at the threshold of pH 5.0. The calculation of Visual MINTEQ model showed that 80.7-96.3% of Fe(II), Zn(II), Pb(II), and Cu(II) existed in divalent free ions, while 71.7% of Fe(III) and 71.5% of Al(III) were complexed by oxalate and fluoride, respectively. ACIs could markedly change the speciation distributions of trace elements in cloud water by pH modification. The in-cloud scavenging of aerosol trace elements likely reached a peak after the first 2-3 h of cloud processing, with scavenging ratios between 0.12 for Cr and 0.57 for Pb. The increases of the trace element solubility (4-33%) were determined in both in-cloud aerosols and postcloud aerosols. These results indicated the significant importance of aerosol-cloud interactions to the evolution of trace elements during the first several cloud condensation/evaporation cycles.

Trace element concentrations in liver of 16 species of cetaceans stranded on Pacific Islands from 1997 through 2013

PubMed Central

Hansen, Angela M. K.; Bryan, Colleen E.; West, Kristi; Jensen, Brenda A.

2016-01-01

The impacts of anthropogenic contaminants on marine ecosystems are a concern worldwide. Anthropogenic activities can enrich trace elements in marine biota to concentrations that may negatively impact organism health. Exposure to elevated concentrations of trace elements is considered a contributing factor in marine mammal population declines. Hawai'i is an increasingly important geographic location for global monitoring, yet trace element concentrations have not been quantified in Hawaiian cetaceans, and there is little trace element data for Pacific cetaceans. This study measured trace elements (Cr, Mn, Cu, Zn, As, Se, Sr, Cd, Sn, Hg, and Pb) in liver of 16 species of cetaceans that stranded on U.S. Pacific Islands from 1997–2013, using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) (n = 31), and direct mercury analysis atomic absorption spectrometry (DMA-AAS) (n = 43). Concentration ranges (µg/g wet mass fraction) for non-essential trace elements such as Cd (0.0031–58.93) and Hg (0.0062–1571.75) were much greater than essential trace elements such as Mn (0.590–17.31) and Zn (14.72–245.38). Differences were found among age classes in Cu, Zn, Hg, and Se concentrations. The highest concentrations of Se, Cd, Sn, Hg, and Pb were found in one adult female false killer whale (Pseudorca crassidens) at concentrations that are known to affect health in marine mammals. The results of this study establish initial trace element concentration ranges for Pacific cetaceans in the Hawaiian Islands region, provide insights into contaminant exposure of these marine mammals, and contribute to a greater understanding of anthropogenic impacts in the Pacific Ocean. PMID:26283019

Trace Element Concentrations in Liver of 16 Species of Cetaceans Stranded on Pacific Islands from 1997 through 2013.

PubMed

Hansen, Angela M K; Bryan, Colleen E; West, Kristi; Jensen, Brenda A

2016-01-01

The impacts of anthropogenic contaminants on marine ecosystems are a concern worldwide. Anthropogenic activities can enrich trace elements in marine biota to concentrations that may negatively impact organism health. Exposure to elevated concentrations of trace elements is considered a contributing factor in marine mammal population declines. Hawai'i is an increasingly important geographic location for global monitoring, yet trace element concentrations have not been quantified in Hawaiian cetaceans, and there is little trace element data for Pacific cetaceans. This study measured trace elements (Cr, Mn, Cu, Zn, As, Se, Sr, Cd, Sn, Hg, and Pb) in liver of 16 species of cetaceans that stranded on U.S. Pacific Islands from 1997 to 2013, using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) (n = 31), and direct mercury analysis atomic absorption spectrometry (DMA-AAS) (n = 43). Concentration ranges (μg/g wet mass fraction) for non-essential trace elements, such as Cd (0.0031-58.93) and Hg (0.0062-1571.75) were much greater than essential trace elements, such as Mn (0.590-17.31) and Zn (14.72-245.38). Differences were found among age classes in Cu, Zn, Hg, and Se concentrations. The highest concentrations of Se, Cd, Sn, Hg, and Pb were found in one adult female false killer whale (Pseudorca crassidens) at concentrations that are known to affect health in marine mammals. The results of this study establish initial trace element concentration ranges for Pacific cetaceans in the Hawaiian Islands region, provide insights into contaminant exposure of these marine mammals, and contribute to a greater understanding of anthropogenic impacts in the Pacific Ocean.

Trace Elements Affect Methanogenic Activity and Diversity in Enrichments from Subsurface Coal Bed Produced Water

PubMed Central

Ünal, Burcu; Perry, Verlin Ryan; Sheth, Mili; Gomez-Alvarez, Vicente; Chin, Kuk-Jeong; Nüsslein, Klaus

2012-01-01

Microbial methane from coal beds accounts for a significant and growing percentage of natural gas worldwide. Our knowledge of physical and geochemical factors regulating methanogenesis is still in its infancy. We hypothesized that in these closed systems, trace elements (as micronutrients) are a limiting factor for methanogenic growth and activity. Trace elements are essential components of enzymes or cofactors of metabolic pathways associated with methanogenesis. This study examined the effects of eight trace elements (iron, nickel, cobalt, molybdenum, zinc, manganese, boron, and copper) on methane production, on mcrA transcript levels, and on methanogenic community structure in enrichment cultures obtained from coal bed methane (CBM) well produced water samples from the Powder River Basin, Wyoming. Methane production was shown to be limited both by a lack of additional trace elements as well as by the addition of an overly concentrated trace element mixture. Addition of trace elements at concentrations optimized for standard media enhanced methane production by 37%. After 7 days of incubation, the levels of mcrA transcripts in enrichment cultures with trace element amendment were much higher than in cultures without amendment. Transcript levels of mcrA correlated positively with elevated rates of methane production in supplemented enrichments (R2 = 0.95). Metabolically active methanogens, identified by clone sequences of mcrA mRNA retrieved from enrichment cultures, were closely related to Methanobacterium subterraneum and Methanobacterium formicicum. Enrichment cultures were dominated by M. subterraneum and had slightly higher predicted methanogenic richness, but less diversity than enrichment cultures without amendments. These results suggest that varying concentrations of trace elements in produced water from different subsurface coal wells may cause changing levels of CBM production and alter the composition of the active methanogenic community. PMID:22590465

Trace Element Concentrations in Beef Cattle Related to the Breed Aptitude.

PubMed

Pereira, Victor; Carbajales, Paloma; López-Alonso, Marta; Miranda, Marta

2018-02-24

Animal feed has traditionally been supplemented with trace elements at dietary concentrations well above physiological needs. However, environmental concerns have led to calls for better adjustment of mineral supplementation to actual physiological needs and, in this context, consideration of breed-related differences in trace element requirements. The aim of this study was to analyze trace element concentrations in the main breeds used for intensive beef production in northern Spain (Holstein-Friesian [HF], Galician Blonde [GB], and GB × HF cross). Samples of blood, internal organs, and muscle were obtained at slaughter from 10 HF, GB, and GB × HF cross calves in the same feedlot. Overall, trace element concentrations in serum and internal organs were within adequate ranges and did not differ between those of breeds, suggesting that trace mineral supplementation was adequate in all groups. The only exception to this was copper, and hepatic copper concentrations were above adequate levels in all calves. This was particularly evident in the HF calves, and the maximum recommended level for human consumption was exceeded in 90% of these animals. Copper, iron, manganese, selenium, and zinc concentrations in muscle were significantly higher in the HF than those in the GB calves, with intermediate values for the crosses. These breed-related differences in trace element concentrations in the muscle may be related to lower muscle mass and/or higher hepatic activity in the HF (dairy) calves than in GB (beef) calves. As meat is an essential source of highly available trace elements in human diets, breed-related differences in trace element concentrations in meat deserve further investigation.

Trace Elements in Parenteral Nutrition: Considerations for the Prescribing Clinician

PubMed Central

Jin, Jennifer; Mulesa, Leanne; Carrilero Rouillet, Mariana

2017-01-01

Trace elements (TEs) are an essential component of parenteral nutrition (PN). Over the last few decades, there has been increased experience with PN, and with this knowledge more information about the management of trace elements has become available. There is increasing awareness of the effects of deficiencies and toxicities of certain trace elements. Despite this heightened awareness, much is still unknown in terms of trace element monitoring, the accuracy of different assays, and current TE contamination of solutions. The supplementation of TEs is a complex and important part of the PN prescription. Understanding the role of different disease states and the need for reduced or increased doses is essential. Given the heterogeneity of the PN patients, supplementation should be individualized. PMID:28452962

Trace elements in parenteral nutrition: a practical guide for dosage and monitoring for adult patients.

PubMed

Fessler, Theresa A

2013-12-01

Parenteral nutrition (PN) is a life-sustaining therapy for hundreds of thousands of people who have severe impairment of gastrointestinal function. Trace elements are a small but very important part of PN that can be overlooked during busy practice. Serious complications can result from trace element deficiencies and toxicities, and this is especially problematic during times of product shortages. Practical information on parenteral trace element use can be gleaned from case reports, some retrospective studies, and very few randomized controlled trials. A general knowledge of trace element metabolism and excretion, deficiency and toxicity symptoms, products, optimal dosages, and strategies for supplementation, restriction, and monitoring will equip practitioners to provide optimal care for their patients who depend on PN.

Trace Elements in Parenteral Nutrition: Considerations for the Prescribing Clinician.

PubMed

Jin, Jennifer; Mulesa, Leanne; Carrilero Rouillet, Mariana

2017-04-28

Trace elements (TEs) are an essential component of parenteral nutrition (PN). Over the last few decades, there has been increased experience with PN, and with this knowledge more information about the management of trace elements has become available. There is increasing awareness of the effects of deficiencies and toxicities of certain trace elements. Despite this heightened awareness, much is still unknown in terms of trace element monitoring, the accuracy of different assays, and current TE contamination of solutions. The supplementation of TEs is a complex and important part of the PN prescription. Understanding the role of different disease states and the need for reduced or increased doses is essential. Given the heterogeneity of the PN patients, supplementation should be individualized.

Profiles of non-essential trace elements in ewe and goat milk and their yoghurt, Torba yoghurt and whey.

PubMed

Sanal, Hasan; Güler, Zehra; Park, Young W

2011-01-01

The objectives of this study were to determine the profiles of non-essential trace elements in ewes' and goats' milk and manufactured products, such as yoghurt, torba yoghurt and whey, as well as changes in trace element content during Torba yoghurt-making processes. Concentrations of non-essential trace elements in ewe (Awassi) and goat (Damascus) milk and their yoghurt, torba yoghurt and whey were quantitatively determined by simultaneous inductively coupled plasma optical emission spectrometer (ICP-OES), after microwave digestion. Aluminium, antimony, arsenic, boron, beryllium, cadmium, nickel, lead, silver, titanium, thallium and vanadium were determined for both types of milk and their products. Barium was not detected in goats' milk or their products. Among all trace elements, boron was the most abundant and beryllium was least present in milk and the manufactured products. The results showed that goats' and ewes' milk and their manufactured products may be a source of 13 non-essential trace elements.

Geological occurrence response to trace elemental migration in coal liquefaction based on SPSS: take no. 11 coalbed in Antaibao mine for example

NASA Astrophysics Data System (ADS)

Xia, Xiaohong; Qin, Yong; Yang, Weifeng

2013-03-01

Coal liquefaction is an adoptable method to transfer the solid fossil energy into liquid oil in large scale, but the dirty material in which will migrate to different step of liquefaction. The migration rule of some trace elements is response to the react activity of macerals in coal and the geological occurrence of the element nature of itself. In this paper, from the SPSS data correlation analysis and hierarchical clustering dendrogram about the trace elements with macerals respond to coal liquefaction yield, it shows the trace elements in No.11 Antaibao coal seam originated from some of lithophile and sulphophle elements. Correlation coefficient between liquefaction yield of three organic macerals and migration of the elements in liquefaction residue indicated that the lithophile are easy to transfer to residue, while sulphophle are apt to in the liquid products. The activated macerals are response to sulphophle trace elements. The conclusion is useful to the coal blending and environmental effects on coal direct liquefaction.

Variation in Macro and Trace Elements in Progression of Type 2 Diabetes

PubMed Central

2014-01-01

Macro elements are the minerals of which the body needs more amounts and are more important than any other elements. Trace elements constitute a minute part of the living tissues and have various metabolic characteristics and functions. Trace elements participate in tissue and cellular and subcellular functions; these include immune regulation by humoral and cellular mechanisms, nerve conduction, muscle contractions, membrane potential regulations, and mitochondrial activity and enzyme reactions. The status of micronutrients such as iron and vanadium is higher in type 2 diabetes. The calcium, magnesium, sodium, chromium, cobalt, iodine, iron, selenium, manganese, and zinc seem to be low in type 2 diabetes while elements such as potassium and copper have no effect. In this review, we emphasized the status of macro and trace elements in type 2 diabetes and its advantages or disadvantages; this helps to understand the mechanism, progression, and prevention of type 2 diabetes due to the lack and deficiency of different macro and trace elements. PMID:25162051

Fish predation by semi-aquatic spiders: a global pattern.

PubMed

Nyffeler, Martin; Pusey, Bradley J

2014-01-01

More than 80 incidences of fish predation by semi-aquatic spiders--observed at the fringes of shallow freshwater streams, rivers, lakes, ponds, swamps, and fens--are reviewed. We provide evidence that fish predation by semi-aquatic spiders is geographically widespread, occurring on all continents except Antarctica. Fish predation by spiders appears to be more common in warmer areas between 40° S and 40° N. The fish captured by spiders, usually ranging from 2-6 cm in length, are among the most common fish taxa occurring in their respective geographic area (e.g., mosquitofish [Gambusia spp.] in the southeastern USA, fish of the order Characiformes in the Neotropics, killifish [Aphyosemion spp.] in Central and West Africa, as well as Australian native fish of the genera Galaxias, Melanotaenia, and Pseudomugil). Naturally occurring fish predation has been witnessed in more than a dozen spider species from the superfamily Lycosoidea (families Pisauridae, Trechaleidae, and Lycosidae), in two species of the superfamily Ctenoidea (family Ctenidae), and in one species of the superfamily Corinnoidea (family Liocranidae). The majority of reports on fish predation by spiders referred to pisaurid spiders of the genera Dolomedes and Nilus (>75% of observed incidences). There is laboratory evidence that spiders from several more families (e.g., the water spider Argyroneta aquatica [Cybaeidae], the intertidal spider Desis marina [Desidae], and the 'swimming' huntsman spider Heteropoda natans [Sparassidae]) predate fish as well. Our finding of such a large diversity of spider families being engaged in fish predation is novel. Semi-aquatic spiders captured fish whose body length exceeded the spiders' body length (the captured fish being, on average, 2.2 times as long as the spiders). Evidence suggests that fish prey might be an occasional prey item of substantial nutritional importance.

Effects of attention manipulations on motivated attention to feared and nonfeared negative distracters in spider fear.

PubMed

Norberg, Joakim; Wiens, Stefan

2013-11-09

When people view emotional and neutral pictures, the emotional pictures capture more attention than do neutral pictures. In support, studies with event-related potentials have shown that the early posterior negativity (EPN) and the late positive potential (LPP) to emotional versus neutral pictures are enhanced when pictures are attended. However, this motivated attention decreases when voluntary attention is directed away from the pictures. Most previous studies included only generally emotional pictures of either negative or positive valence. Because people with spider fear report intense fear of spiders, we examined whether directing attention away from emotional pictures at fixation decreases motivated attention less strongly for spiders than for generally negative distracters. We recorded event-related potentials from 128 channels to study whether manipulations of attention (i.e., spatial attention and perceptual load) decrease the EPN and the LPP to emotional distracters less strongly for spiders than for fear-irrelevant negative pictures in people with spider fear. Results confirmed that the EPN and the LPP to spiders (vs. neutral pictures) were particularly enhanced in participants with spider fear compared to participants without spider fear. When attention was directed away from the pictures, the EPN and the LPP to spiders (vs. neutral pictures) decreased similarly in fearful and nonfearful participants. Further, in fearful participants, the decrease in the EPN and the LPP was similar for spiders and for fear-irrelevant negative pictures. Our findings suggest that for people with spider fear, directing attention away from emotional pictures at fixation decreases motivated attention to these distracters similarly for spiders as for fear-irrelevant negative pictures. These findings imply that attention to spiders in spider fear does not exceed the level of attention expected from the spider pictures' high arousal and negative valence (i.e., their intrinsic motivated attention).

Upside-down spiders build upside-down orb webs: web asymmetry, spider orientation and running speed in Cyclosa.

PubMed

Nakata, Kensuke; Zschokke, Samuel

2010-10-07

Almost all spiders building vertical orb webs face downwards when sitting on the hubs of their webs, and their webs exhibit an up-down size asymmetry, with the lower part of the capture area being larger than the upper. However, spiders of the genus Cyclosa, which all build vertical orb webs, exhibit inter- and intraspecific variation in orientation. In particular, Cyclosa ginnaga and C. argenteoalba always face upwards, and C. octotuberculata always face downwards, whereas some C. confusa face upwards and others face downwards or even sideways. These spiders provide a unique opportunity to examine why most spiders face downwards and have asymmetrical webs. We found that upward-facing spiders had upside-down webs with larger upper parts, downward-facing spiders had normal webs with larger lower parts and sideways-facing spiders had more symmetrical webs. Downward-facing C. confusa spiders were larger than upward- and sideways-facing individuals. We also found that during prey attacks, downward-facing spiders ran significantly faster downwards than upwards, which was not the case in upward-facing spiders. These results suggest that the spider's orientation at the hub and web asymmetry enhance its foraging efficiency by minimizing the time to reach prey trapped in the web.

Upside-down spiders build upside-down orb webs: web asymmetry, spider orientation and running speed in Cyclosa

PubMed Central

Nakata, Kensuke; Zschokke, Samuel

2010-01-01

Almost all spiders building vertical orb webs face downwards when sitting on the hubs of their webs, and their webs exhibit an up–down size asymmetry, with the lower part of the capture area being larger than the upper. However, spiders of the genus Cyclosa, which all build vertical orb webs, exhibit inter- and intraspecific variation in orientation. In particular, Cyclosa ginnaga and C. argenteoalba always face upwards, and C. octotuberculata always face downwards, whereas some C. confusa face upwards and others face downwards or even sideways. These spiders provide a unique opportunity to examine why most spiders face downwards and have asymmetrical webs. We found that upward-facing spiders had upside-down webs with larger upper parts, downward-facing spiders had normal webs with larger lower parts and sideways-facing spiders had more symmetrical webs. Downward-facing C. confusa spiders were larger than upward- and sideways-facing individuals. We also found that during prey attacks, downward-facing spiders ran significantly faster downwards than upwards, which was not the case in upward-facing spiders. These results suggest that the spider's orientation at the hub and web asymmetry enhance its foraging efficiency by minimizing the time to reach prey trapped in the web. PMID:20462900

Salticid predation as one potential driving force of ant mimicry in jumping spiders

PubMed Central

Huang, Jin-Nan; Cheng, Ren-Chung; Li, Daiqin; Tso, I-Min

2011-01-01

Many spiders possess myrmecomorphy, and species of the jumping spider genus Myrmarachne exhibit nearly perfect ant mimicry. Most salticids are diurnal predators with unusually high visual acuity that prey on various arthropods, including conspecifics. In this study, we tested whether predation pressure from large jumping spiders is one possible driving force of perfect ant mimicry in jumping spiders. The results showed that small non-ant-mimicking jumping spiders were readily treated as prey by large ones (no matter whether heterospecific or conspecific) and suffered high attack and mortality rates. The size difference between small and large jumping spiders significantly affected the outcomes of predatory interactions between them: the smaller the juvenile jumping spiders, the higher the predation risk from large ones. The attack and mortality rates of ant-mimicking jumping spiders were significantly lower than those of non-ant-mimicking jumping spiders, indicating that a resemblance to ants could provide protection against salticid predation. However, results of multivariate behavioural analyses showed that the responses of large jumping spiders to ants and ant-mimicking salticids differed significantly. Results of this study indicate that predation pressure from large jumping spiders might be one selection force driving the evolution of nearly perfect myrmecomorphy in spiders and other arthropods. PMID:20961898

Alleviation of environmental risks associated with severely contaminated mine tailings using amendments: Modeling of trace element speciation, solubility, and plant accumulation.

PubMed

Pardo, Tania; Bes, Cleménce; Bernal, Maria Pilar; Clemente, Rafael

2016-11-01

Tailings are considered one of the most relevant sources of contamination associated with mining activities. Phytostabilization of mine spoils may need the application of the adequate combination of amendments to facilitate plant establishment and reduce their environmental impact. Two pot experiments were set up to assess the capability of 2 inorganic materials (calcium carbonate and a red mud derivate, ViroBind TM ), alone or in combination with organic amendments, for the stabilization of highly acidic trace element-contaminated mine tailings using Atriplex halimus. The effects of the treatments on tailings and porewater physico-chemical properties and trace-element accumulation by the plants, as well as the processes governing trace elements speciation and solubility in soil solution and their bioavailability were modeled. The application of the amendments increased tailings pH and decreased (>99%) trace elements solubility in porewater, but also changed the speciation of soluble Cd, Cu, and Pb. All the treatments made A. halimus growth in the tailings possible; organic amendments increased plant biomass and nutritional status, and reduced trace-element accumulation in the plants. Tailings amendments modified trace-element speciation in porewater (favoring the formation of chlorides and/or organo-metallic forms) and their solubility and plant uptake, which were found to be mainly governed by tailing/porewater pH, electrical conductivity, and organic carbon content, as well as soluble/available trace-element concentrations. Environ Toxicol Chem 2016;35:2874-2884. © 2016 SETAC. © 2016 SETAC.

The geographic distribution of trace elements in the environment: the REGARDS study.

PubMed

Rembert, Nicole; He, Ka; Judd, Suzanne E; McClure, Leslie A

2017-02-01

Research on trace elements and the effects of their ingestion on human health is often seen in scientific literature. However, little research has been done on the distribution of trace elements in the environment and their impact on health. This paper examines what characteristics among participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study are associated with levels of environmental exposure to arsenic, magnesium, mercury, and selenium. Demographic information from REGARDS participants was combined with trace element concentration data from the US Geochemical Survey (USGS). Each trace element was characterized as either low (magnesium and selenium) or high (arsenic and mercury) exposure. Associations between demographic characteristics and trace element concentrations were analyzed with unadjusted and adjusted logistic regression models. Individuals who reside in the Stroke Belt have lower odds of high exposure (4th quartile) to arsenic (OR 0.33, CI 0.31, 0.35) and increased exposure to mercury (OR 0.65, CI 0.62, 0.70) than those living outside of these areas, while the odds of low exposure to trace element concentrations were increased for magnesium (OR 5.48, CI 5.05, 5.95) and selenium (OR 2.37, CI 2.22, 2.54). We found an association between levels of trace elements in the environment and geographic region of residence, among other factors. Future studies are needed to further examine this association and determine whether or not these differences may be related to geographic variation in disease.

Level of minerals and trace elements in the urine of the participants of mountain ultra-marathon race.

PubMed

Jablan, Jasna; Inić, Suzana; Stosnach, Hagen; Hadžiabdić, Maja Ortner; Vujić, Lovorka; Domijan, Ana-Marija

2017-05-01

The aim of the present study was to explore impact of endurance exercise on urinary level of minerals and trace elements as well as on some oxidative stress and biochemical parameters. Urine samples were collected from participants (n=21) of mountain ultra-marathon race (53km; Medvednica, Zagreb, Croatia), before (baseline value), immediately after, 12h and 24h after the race. In urine samples level of minerals (Ca, P, K and Na) and trace elements (Se, Zn, Mn, Cu, Fe and Co) were assessed using the bench top Total reflection X-ray Fluorescence (TXRF) spectrometer. Oxidative stress was determined as level of malondialdehyde (MDA). Immediately after the race level of minerals, trace elements, MDA, creatinine, ketones, erythrocytes and specific gravity increased compared to their baseline value. In 24h follow-up trace elements involved in antioxidant defence, MDA and biochemical parameters returned to their baseline values, Cu and Co remained increased as after the race, Fe and K tended to return to baseline values while Ca, P and Na continued to increase. Mountain ultra-marathon resulted in alteration of physiologically important minerals and trace elements that for some minerals and trace elements persist, indicating their involvement in recovery processes. However, due to their loss in urine, level of minerals and trace elements in athletes participating in endurance exercise should be monitored. Copyright © 2017 Elsevier GmbH. All rights reserved.

Attentional bias to moving spiders in spider fearful individuals.

PubMed

Vrijsen, Janna N; Fleurkens, Pascal; Nieuwboer, Wieteke; Rinck, Mike

2009-05-01

We investigated if an attentional bias for spiders in spider fearful individuals (SFs) can also be found for moving spiders, rather than static images. In Study 1, 28 SFs and 33 non-anxious controls (NACs) participated in a modified version of the dot probe paradigm: they had to react to a probe that appeared either in the next, previous, or side position of a spider's or a wheel's path. 24 SFs and 29 NACs participated in Study 2, in which a fourth, highly predictable, probe position was added. We expected that moving spiders would capture the attention of SFs. In addition, we tested whether SFs try to predict the movement of the spider to make it less threatening. As expected, SFs showed an attentional bias towards moving spiders. However, both groups reacted fastest to unpredictable movements, indicating that SFs and NACs alike anticipate unpredictable spider movements.

Seasonal Dynamics of Trace Elements in Tidal Salt Marsh Soils as Affected by the Flow-Sediment Regulation Regime

PubMed Central

Bai, Junhong; Xiao, Rong; Zhao, Qingqing; Lu, Qiongqiong; Wang, Junjing; Reddy, K. Ramesh

2014-01-01

Soil profiles were collected in three salt marshes with different plant species (i.e. Phragmites australis, Tamarix chinensis and Suaeda salsa) in the Yellow River Delta (YRD) of China during three seasons (summer and fall of 2007 and the following spring of 2008) after the flow-sediment regulation regime. Total elemental contents of As, Cd, Cu, Pb and Zn were determined using inductively coupled plasma atomic absorption spectrometry to investigate temporal variations in trace elements in soil profiles of the three salt marshes, assess the enrichment levels and ecological risks of these trace elements in three sampling seasons and identify their influencing factors. Trace elements did not change significantly along soil profiles at each site in each sampling season. The highest value for each sampling site was observed in summer and the lowest one in fall. Soils in both P. australis and S. salsa wetlands tended to have higher trace element levels than those in T. chinensis wetland. Compared to other elements, both Cd and As had higher enrichment factors exceeding moderate enrichment levels. However, the toxic unit (TU) values of these trace elements did not exceed probable effect levels. Correlation analysis showed that these trace elements were closely linked to soil properties such as moisture, sulfur, salinity, soil organic matter, soil texture and pH values. Principal component analysis showed that the sampling season affected by the flow-sediment regulation regime was the dominant factor influencing the distribution patterns of these trace elements in soils, and plant community type was another important factor. The findings of this study could contribute to wetland conservation and management in coastal regions affected by the hydrological engineering. PMID:25216278

Spider fauna of semiarid eastern Colorado agroecosystems: diversity, abundance, and effects of crop intensification.

PubMed

Kerzicnik, Lauren M; Peairs, Frank B; Cushing, Paula E; Draney, Michael L; Merrill, Scott C

2013-02-01

Spiders are critical predators in agroecosystems. Crop management practices can influence predator density and diversity, which, in turn, can influence pest management strategies. Crop intensification is a sustainable agricultural technique that can enhance crop production although optimizing soil moisture. To date, there is no information on how crop intensification affects natural enemy populations, particularly spiders. This study had two objectives: to characterize the abundance and diversity of spiders in eastern Colorado agroecosystems, and to test the hypothesis that spider diversity and density would be higher in wheat (Triticum aestivum L.) in crop-intensified rotations compared with wheat in conventional rotations. We collected spiders through pitfall, vacuum, and lookdown sampling from 2002 to 2007 to test these objectives. Over 11,000 spiders in 19 families from 119 species were captured from all sampling techniques. Interestingly, the hunting spider guild represented 89% of the spider fauna captured from all sites with the families Gnaphosidae and Lycosidae representing 75% of these spiders. Compared with European agroecosystems, these agroecosystems had greater diversity, which can be beneficial for the biological control of pests. Overall, spider densities were low in these semiarid cropping systems, and crop intensification effects on spider densities were not evident at this scale.

Nanofiber-net-binary structured membranes for highly sensitive detection of trace HCl gas

NASA Astrophysics Data System (ADS)

Wang, Xianfeng; Wang, Jialin; Si, Yang; Ding, Bin; Yu, Jianyong; Sun, Gang; Luo, Wenjing; Zheng, Gang

2012-11-01

This work describes the detection of trace hydrogen chloride (HCl) gas through analyses of the resonance frequency signal from quartz crystal microbalance (QCM) sensors coated with polyaniline (PANI) functionalized polyamide 6 (PA 6) (PANI-PA 6) nanofiber-net-binary (NNB) structured membranes. The PA 6 NNB substrate comprising nanofibers and spider-web-like nano-nets fabricated by a versatile electro-spinning/netting (ESN) process offered an ideal interface for the uniform PANI functionalization and enhanced sensing performance. Benefiting from the large specific surface area, high porosity, and strong adhesive force to the QCM electrode of the PANI-PA 6 NNB membranes, the developed HCl-selective sensors exhibited a rapid response, good reproducibility and stability, and low detection limit (7 ppb) at room temperature. Additionally, the PANI-PA 6 NNB sensing membranes presented visible color changes upon cycled exposure to HCl and ammonia, suggesting their potential application in the development of colorimetric sensors. The PANI-PA 6 NNB coated QCM sensors are considered to be a promising candidate for trace HCl gas detection in practical applications.

Phobic spider fear is associated with enhanced attentional capture by spider pictures: a rapid serial presentation event-related potential study.

PubMed

Van Strien, Jan W; Franken, Ingmar H A; Huijding, Jorg

2009-03-04

The early posterior negativity (EPN) reflects early selective visual processing of emotionally significant information. This study explored the association between fear of spiders and the EPN for spider pictures. Fifty women completed a Spider Phobia Questionnaire and watched the random rapid serial presentation of 600 neutral, 600 negatively valenced emotional, and 600 spider pictures (three pictures per second). The EPN was scored as the mean activity in the 225-300-ms time window at lateral occipital electrodes. Participants with higher scores on the phobia questionnaire showed larger (i.e. more negative) EPN amplitudes in response to spider pictures. The results suggest that the attentional capture of spider-related stimuli is an automatic response, which is modulated by the extent of spider fear.

Specialised use of working memory by Portia africana, a spider-eating salticid.

PubMed

Cross, Fiona R; Jackson, Robert R

2014-03-01

Using expectancy-violation methods, we investigated the role of working memory in the predatory strategy of Portia africana, a salticid spider from Kenya that preys by preference on other spiders. One of this predator's tactics is to launch opportunistic leaping attacks on to other spiders in their webs. Focussing on this particular tactic, our experiments began with a test spider on a ramp facing a lure (dead prey spider mounted on a cork disc) that could be reached by leaping. After the test spider faced the lure for 30 s, we blocked the test spider's view of the lure by lowering an opaque shutter before the spider leapt. When the shutter was raised 90 s later, either the same lure came into view again (control) or a different lure came into view (experimental: different prey type in same orientation or same prey type in different orientation). We recorded attack frequency (number of test spiders that leapt at the lure) and attack latency (time elapsing between shutter being raised and spiders initiating a leap). Attack latencies in control trials were not significantly different from attack latencies in experimental trials, regardless of whether it was prey type or prey orientation that changed in the experimental trials. However, compared with test spiders in the no-change control trials, significantly fewer test spiders leapt when prey type changed. There was no significant effect on attack frequency when prey orientation changed. These findings suggest that this predator represents prey type independently of prey orientation.

Ecosystem services in the face of invasion: the persistence of native and nonnative spiders in an agricultural landscape.

PubMed

Hogg, Brian N; Daane, Kent M

2011-03-01

The presence of intact natural ecosystems in agricultural landscapes can mitigate losses in the diversity of natural enemies and enhance ecosystem services. However, native natural enemies may fail to persist in agroecosystems if invaders dominate species interactions. In this study, native and nonnative spiders were sampled along transects that extended from oak woodland and riparian zones into surrounding California vineyards, to assess the role of natural habitat as a source for spider biodiversity in the vineyard landscape, and to compare the dominance of exotic Cheiracanthium spiders between habitats. Many spider species were more abundant in natural habitat than in vineyards, and numbers of spiders and spider species within vineyards were higher at the vineyard edge adjacent to oak woodland. These results suggest that natural habitat is a key source for spiders in vineyards. The positive effect of oak woodland on the vineyard spider community extended only to the vineyard edge, however. Proportions of Cheiracanthium spiders increased dramatically in the vineyard, while numbers of native wandering spiders (the native ecological homologues of Cheiracanthium spiders) decreased. Dispersal limitation and strong habitat preferences may have prevented native wandering spiders from establishing far from the vineyard edge. Exotic Cheiracanthium spiders, in contrast, may possess specific adaptations to vineyards or to a wide range of habitats. Results suggest that the ecosystem services provided by intact natural habitat may be limited in agricultural landscapes that are dominated by invasive species.

Progress of pharmacogenomic research related to minerals and trace elements.

PubMed

Zeng, Mei-Zi; Tang, Jie; Liu, Zhao-Qian; Zhou, Hong-Hao; Zhang, Wei

2015-10-01

Pharmacogenomics explores the variations in both the benefits and the adverse effects of a drug among patients in a target population by analyzing genomic profiles of individual patients. Minerals and trace elements, which can be found in human tissues and maintain normal physiological functions, are also in the focus of pharmacogenomic research. Single-nucleotide polymorphisms (SNPs) affect the metabolism, disposition and efficacy of minerals and trace elements in humans, resulting in changes of body function. This review describes some of the recent progress in pharmacogenomic research related to minerals and trace elements.

Stability of hydrophilic vitamins mixtures in the presence of electrolytes and trace elements for parenteral nutrition: a nuclear magnetic resonance spectroscopy investigation.

PubMed

Uccello-Barretta, Gloria; Balzano, Federica; Aiello, Federica; Falugiani, Niccolò; Desideri, Ielizza

2015-03-25

In total parenteral nutrition (TPN), especially in the case of preterm infants, simultaneous administration of vitamins and trace elements is still a problematic issue: guidelines put in evidence the lack of specific documentation. In this work NMR spectroscopy was applied to the study of vitamins (pyridoxine hydrochloride, thiamine nitrate, riboflavin-5'-phosphate and nicotinamide) stability in presence of salts and trace elements. Vitamins in D2O were first analyzed by (1)H NMR spectroscopy in absence of salts and trace elements; changes in chemical shifts or in diffusion coefficients, measured by NMR DOSY technique, were analyzed. The effects of salts and trace elements on single vitamins and on their admixtures were then investigated by performing quantitative analyses during 48h. Selected vitamins are subject to intermolecular interactions. No degradative effects were observed in presence of salts and trace elements. Only riboflavin-5'-phosphate is subject to precipitation in presence of divalent cations; however, at low concentration and in presence of other vitamins this effect was not observed. Solutions analyzed, in the condition of this study, are stable for at least 48h and vitamins and trace elements can be administered together in TPN. Copyright © 2014 Elsevier B.V. All rights reserved.

Toxic effects of trace elements on newborns and their birth outcomes.

PubMed

Tang, Mengling; Xu, Chenye; Lin, Nan; Yin, Shanshan; Zhang, Yongli; Yu, Xinwei; Liu, Weiping

2016-04-15

Some trace elements are essential for newborns, their deficiency may cause abnormal biological functions, whereas excessive intakes due to environmental contamination may create adverse health effects. This study was conducted to measure the levels of selected trace elements in Chinese fish consumers by assessing their essentiality and toxicity via colostrum intake in newborns, and evaluated the effects of these trace elements on birth outcomes. Trace elements in umbilical cord serum and colostrum of the studied population were relatively high compared with other populations. The geometric means (GM) of estimated daily intake (EDI, mgday(-1)) of the trace elements were in the safe ranges for infant Dietary Reference Intakes (DRIs) recommended by the United States Food and Drug Administration (FDA). When using total dietary intake (TDI, mgkg(-1)bwday(-1)), zinc (Zn) (0.880mgkg(-1)bwday(-1)) and selenium (Se) (6.39×10(-3)mgkg(-1)bwday(-1)) were above the Reference Doses (RfD), set by the United States Environmental Protection Agency (EPA). Multivariable linear regression analyses showed that Se was negatively correlated with birth outcomes. Our findings suggested that overloading of trace elements due to environmental contamination may contribute to negative birth outcomes. Copyright © 2016 Elsevier B.V. All rights reserved.

TRACE ELEMENT ANALYSES OF URANIUM MATERIALS

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

Beals, D; Charles Shick, C

The Savannah River National Laboratory (SRNL) has developed an analytical method to measure many trace elements in a variety of uranium materials at the high part-per-billion (ppb) to low part-per-million (ppm) levels using matrix removal and analysis by quadrapole ICP-MS. Over 35 elements were measured in uranium oxides, acetate, ore and metal. Replicate analyses of samples did provide precise results however none of the materials was certified for trace element content thus no measure of the accuracy could be made. The DOE New Brunswick Laboratory (NBL) does provide a Certified Reference Material (CRM) that has provisional values for a seriesmore » of trace elements. The NBL CRM were purchased and analyzed to determine the accuracy of the method for the analysis of trace elements in uranium oxide. These results are presented and discussed in the following paper.« less

The Pasamonte unequilibrated eucrite: Pyroxene REE systematic and major-, minor-, and trace-element zoning. [Abstract only

NASA Technical Reports Server (NTRS)

Pun, A.; Papike, J. J.

1994-01-01

We are evaluating the trace-element concentrations in the pyroxenes of Pasamonte. Pasamonte is a characteristic member of the main group eucrites, and has recently been redescribed as a polymict eucrite. Our Pasamonte sample contained eucritic clasts with textures ranging from subophitic to moderately coarse-grained. This study concentrates on pyroxenes from an unequilibrated, coarse-grained eucrite clast. Major-, minor-, and trace-element analyses were measured for zoned pyroxenes in the eucritic clast of Pasamonte. The major- and minor-element zoning traverses were measured using the JEOL 733 electron probe with an Oxford-Link imaging/analysis system. Complemenatry trace elements were then measured for the core and rim of each of the grains by SIMS. The trace elements analyzed consisted of eight REE, Sr, Y, and Zr. These analyses were performed on a Cameca 4f ion probe. The results of the CI chondrite normalized (average CI trace-element analyses for several grains and the major- and minor-element zoning patterns from a single pyroxene grain are given. The Eu abundance in the cores of the pyroxenes represents the detection limit and therefore the (-Eu) anomaly is a minimum. Major- and minor-element patterns are typical for igneous zoning. Pyroxene cores are Mg enriched, whereas the rims are enriched in Fe and Ca. Also, Ti and Mn are found to increase, while Cr and Al generally decrease in core-to-rim traverses. The cores of the pyroxenes are more depleted in the Rare Earth Elements (REE) than the rims. Using the minor- and trace-element concentrations of bulk Pasamonte and the minor- and trace-element concentrations from the cores of the pyroxenes in Pasamonte measured in this study, we calculated partition coefficients between pyroxene and melt. This calculation assumes that bulk Pasamonte is representative of a melt composition.

Reduced trace element concentrations in fast-growing juvenile Atlantic salmon in natural streams.

PubMed

Ward, Darren M; Nislow, Keith H; Chen, Celia Y; Folt, Carol L

2010-05-01

To assess the effect of rapid individual growth on trace element concentrations in fish, we measured concentrations of seven trace elements (As, Cd, Cs, Hg, Pb, Se, Zn) in stream-dwelling Atlantic salmon (Salmo salar) from 15 sites encompassing a 10-fold range in salmon growth. All salmon were hatched under uniform conditions, released into streams, and sampled approximately 120 days later for trace element analysis. For most elements, element concentrations in salmon tracked those in their prey. Fast-growing salmon had lower concentrations of all elements than slow growers, after accounting for prey concentrations. This pattern held for essential and nonessential elements, as well as elements that accumulate from food and those that can accumulate from water. At the sites with the fastest salmon growth, trace element concentrations in salmon were 37% (Cs) to 86% (Pb) lower than at sites where growth was suppressed. Given that concentrations were generally below levels harmful to salmon and that the pattern was consistent across all elements, we suggest that dilution of elements in larger biomass led to lower concentrations in fast-growing fish. Streams that foster rapid, efficient fish growth may produce fish with lower concentrations of elements potentially toxic for human and wildlife consumers.

Assessment of trace elements levels in patients with Type 2 diabetes using multivariate statistical analysis.

PubMed

Badran, M; Morsy, R; Soliman, H; Elnimr, T

2016-01-01

The trace elements metabolism has been reported to possess specific roles in the pathogenesis and progress of diabetes mellitus. Due to the continuous increase in the population of patients with Type 2 diabetes (T2D), this study aims to assess the levels and inter-relationships of fast blood glucose (FBG) and serum trace elements in Type 2 diabetic patients. This study was conducted on 40 Egyptian Type 2 diabetic patients and 36 healthy volunteers (Hospital of Tanta University, Tanta, Egypt). The blood serum was digested and then used to determine the levels of 24 trace elements using an inductive coupled plasma mass spectroscopy (ICP-MS). Multivariate statistical analysis depended on correlation coefficient, cluster analysis (CA) and principal component analysis (PCA), were used to analysis the data. The results exhibited significant changes in FBG and eight of trace elements, Zn, Cu, Se, Fe, Mn, Cr, Mg, and As, levels in the blood serum of Type 2 diabetic patients relative to those of healthy controls. The statistical analyses using multivariate statistical techniques were obvious in the reduction of the experimental variables, and grouping the trace elements in patients into three clusters. The application of PCA revealed a distinct difference in associations of trace elements and their clustering patterns in control and patients group in particular for Mg, Fe, Cu, and Zn that appeared to be the most crucial factors which related with Type 2 diabetes. Therefore, on the basis of this study, the contributors of trace elements content in Type 2 diabetic patients can be determine and specify with correlation relationship and multivariate statistical analysis, which confirm that the alteration of some essential trace metals may play a role in the development of diabetes mellitus. Copyright © 2015 Elsevier GmbH. All rights reserved.

Geochemistry of environmentally sensitive trace elements in Permian coals from the Huainan coalfield, Anhui, China

USGS Publications Warehouse

Chen, J.; Liu, Gaisheng; Jiang, M.; Chou, C.-L.; Li, H.; Wu, B.; Zheng, Lingyun; Jiang, D.

2011-01-01

To study the geochemical characteristics of 11 environmentally sensitive trace elements in the coals of the Permian Period from the Huainan coalfield, Anhui province, China, borehole samples of 336 coals, two partings, and four roof and floor mudstones were collected from mineable coal seams. Major elements and selected trace elements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), and hydride generation atomic absorption spectrometry (HAAS). The depositional environment, abundances, distribution, and modes of occurrence of trace elements were investigated. Results show that clay and carbonate minerals are the principal inorganic constituents in the coals. A lower deltaic plain, where fluvial channel systems developed successively, was the likely depositional environment of the Permian coals in the Huainan coalfield. All major elements have wider variation ranges than those of Chinese coals except for Mg and Fe. The contents of Cr, Co, Ni, and Se are higher than their averages for Chinese coals and world coals. Vertical variations of trace elements in different formations are not significant except for B and Ba. Certain roof and partings are distinctly higher in trace elements than underlying coal bench samples. The modes of occurrence of trace elements vary in different coal seams as a result of different coal-forming environments. Vanadium, Cr, and Th are associated with aluminosilicate minerals, Ba with carbonate minerals, and Cu, Zn, As, Se, and Pb mainly with sulfide minerals. ?? 2011 Elsevier B.V.

Energetics, scaling and sexual size dimorphism of spiders.

PubMed

Grossi, B; Canals, M

2015-03-01

The extreme sexual size dimorphism in spiders has motivated studies for many years. In many species the male can be very small relative to the female. There are several hypotheses trying to explain this fact, most of them emphasizing the role of energy in determining spider size. The aim of this paper is to review the role of energy in sexual size dimorphism of spiders, even for those spiders that do not necessarily live in high foliage, using physical and allometric principles. Here we propose that the cost of transport or equivalently energy expenditure and the speed are traits under selection pressure in male spiders, favoring those of smaller size to reduce travel costs. The morphology of the spiders responds to these selective forces depending upon the lifestyle of the spiders. Climbing and bridging spiders must overcome the force of gravity. If bridging allows faster dispersal, small males would have a selective advantage by enjoying more mating opportunities. In wandering spiders with low population density and as a consequence few male-male interactions, high speed and low energy expenditure or cost of transport should be favored by natural selection. Pendulum mechanics show the advantages of long legs in spiders and their relationship with high speed, even in climbing and bridging spiders. Thus small size, compensated by long legs should be the expected morphology for a fast and mobile male spider.

Trace elements in ocean ridge basalts

NASA Technical Reports Server (NTRS)

Kay, R. W.; Hubbard, N. J.

1978-01-01

A study is made of the trace elements found in ocean ridge basalts. General assumptions regarding melting behavior, trace element fractionation, and alteration effects are presented. Data on the trace elements are grouped according to refractory lithophile elements, refractory siderophile elements, and volatile metals. Variations in ocean ridge basalt chemistry are noted both for regional and temporal characteristics. Ocean ridge basalts are compared to other terrestrial basalts, such as those having La/Yb ratios greater than those of chondrites, and those having La/Yb ratios less than those of chondrites. It is found that (1) as compared to solar or chondrite ratios, ocean ridge basalts have low ratios of large, highly-charged elements to smaller less highly-charged elements, (2) ocean ridge basalts exhibit low ratios of volatile to nonvolatile elements, and (3) the transition metals Cr through Zn in ocean ridge basalts are not fractionated more than a factor of 2 or 3 from the chondritic abundance ratios.

Fish Predation by Semi-Aquatic Spiders: A Global Pattern

PubMed Central

Nyffeler, Martin; Pusey, Bradley J.

2014-01-01

More than 80 incidences of fish predation by semi-aquatic spiders – observed at the fringes of shallow freshwater streams, rivers, lakes, ponds, swamps, and fens – are reviewed. We provide evidence that fish predation by semi-aquatic spiders is geographically widespread, occurring on all continents except Antarctica. Fish predation by spiders appears to be more common in warmer areas between 40° S and 40° N. The fish captured by spiders, usually ranging from 2–6 cm in length, are among the most common fish taxa occurring in their respective geographic area (e.g., mosquitofish [Gambusia spp.] in the southeastern USA, fish of the order Characiformes in the Neotropics, killifish [Aphyosemion spp.] in Central and West Africa, as well as Australian native fish of the genera Galaxias, Melanotaenia, and Pseudomugil). Naturally occurring fish predation has been witnessed in more than a dozen spider species from the superfamily Lycosoidea (families Pisauridae, Trechaleidae, and Lycosidae), in two species of the superfamily Ctenoidea (family Ctenidae), and in one species of the superfamily Corinnoidea (family Liocranidae). The majority of reports on fish predation by spiders referred to pisaurid spiders of the genera Dolomedes and Nilus (>75% of observed incidences). There is laboratory evidence that spiders from several more families (e.g., the water spider Argyroneta aquatica [Cybaeidae], the intertidal spider Desis marina [Desidae], and the ‘swimming’ huntsman spider Heteropoda natans [Sparassidae]) predate fish as well. Our finding of such a large diversity of spider families being engaged in fish predation is novel. Semi-aquatic spiders captured fish whose body length exceeded the spiders’ body length (the captured fish being, on average, 2.2 times as long as the spiders). Evidence suggests that fish prey might be an occasional prey item of substantial nutritional importance. PMID:24940885

Anatomy of a cluster IDP. Part 2: Noble gas abundances, trace element geochemistry, isotopic abundances, and trace organic chemistry of several fragments from L2008#5

NASA Technical Reports Server (NTRS)

Thomas, K. L.; Clemett, S. J.; Flynn, G. J.; Keller, L. P.; Mckay, David S.; Messenger, S.; Nier, A. O.; Schlutter, D. J.; Sutton, S. R.; Walker, R. M.

1994-01-01

The topics discussed include the following: noble gas content and release temperatures; trace element abundances; heating summary of cluster fragments; isotopic measurements; and trace organic chemistry.

A Synopsis of Technical Issues of Concern for Monitoring Trace Elements in Highway and Urban Runoff

USGS Publications Warehouse

Breault, Robert F.; Granato, Gregory E.

2000-01-01

Trace elements, which are regulated for aquatic life protection, are a primary concern in highway- and urban-runoff studies because stormwater runoff may transport these constituents from the land surface to receiving waters. Many of these trace elements are essential for biological activity and become detrimental only when geologic or anthropogenic sources exceed concentrations beyond ranges typical of the natural environment. The Federal Highway Administration and State Transportation Agencies are concerned about the potential effects of highway runoff on the watershed scale and for the management and protection of watersheds. Transportation agencies need information that is documented as valid, current, and scientifically defensible to support planning and management decisions. There are many technical issues of concern for monitoring trace elements; therefore, trace-element data commonly are considered suspect, and the responsibility to provide data-quality information to support the validity of reported results rests with the data-collection agency. Paved surfaces are fundamentally different physically, hydraulically, and chemically from the natural surfaces typical of most freshwater systems that have been the focus of many traceelement- monitoring studies. Existing scientific conceptions of the behavior of trace elements in the environment are based largely upon research on natural systems, rather than on systems typical of pavement runoff. Additionally, the logistics of stormwater sampling are difficult because of the great uncertainty in the occurrence and magnitude of storm events. Therefore, trace-element monitoring programs may be enhanced if monitoring and sampling programs are automated. Automation would standardize the process and provide a continuous record of the variations in flow and water-quality characteristics. Great care is required to collect and process samples in a manner that will minimize potential contamination or attenuation of trace elements and other sources of bias and variability in the sampling process. Trace elements have both natural and anthropogenic sources that may affect the sampling process, including the sample-collection and handling materials used in many trace-element monitoring studies. Trace elements also react with these materials within the timescales typical for collection, processing and analysis of runoff samples. To study the characteristics and potential effects of trace elements in highway and urban runoff, investigators typically sample one or more operationally defined matrixes including: whole water, dissolved (filtered water), suspended sediment, bottom sediment, biological tissue, and contaminant sources. The sampling and analysis of each of these sample matrixes can provide specific information about the occurrence and distribution of trace elements in runoff and receiving waters. There are, however, technical concerns specific to each matrix that must be understood and addressed through use of proper collection and processing protocols. Valid protocols are designed to minimize inherent problems and to maximize the accuracy, precision, comparability, and representativeness of data collected. Documentation, including information about monitoring protocols, quality assurance and quality control efforts, and ancillary data also is necessary to establish data quality. This documentation is especially important for evaluation of historical traceelement monitoring data, because trace-element monitoring protocols and analysis methods have been constantly changing over the past 30 years.

Biased interpretation and memory in children with varying levels of spider fear.

PubMed

Klein, Anke M; Titulaer, Geraldine; Simons, Carlijn; Allart, Esther; de Gier, Erwin; Bögels, Susan M; Becker, Eni S; Rinck, Mike

2014-01-01

This study investigated multiple cognitive biases in children simultaneously, to investigate whether spider-fearful children display an interpretation bias, a recall bias, and source monitoring errors, and whether these biases are specific for spider-related materials. Furthermore, the independent ability of these biases to predict spider fear was investigated. A total of 121 children filled out the Spider Anxiety and Disgust Screening for Children (SADS-C), and they performed an interpretation task, a memory task, and a Behavioural Assessment Test (BAT). As expected, a specific interpretation bias was found: Spider-fearful children showed more negative interpretations of ambiguous spider-related scenarios, but not of other scenarios. We also found specific source monitoring errors: Spider-fearful children made more fear-related source monitoring errors for the spider-related scenarios, but not for the other scenarios. Only limited support was found for a recall bias. Finally, interpretation bias, recall bias, and source monitoring errors predicted unique variance components of spider fear.

Spiders do not evoke greater early posterior negativity in the event-related potential as snakes.

PubMed

He, Hongshen; Kubo, Kenta; Kawai, Nobuyuki

2014-09-10

It has been long believed that both snakes and spiders are archetypal fear stimuli for humans. Furthermore, snakes have been assumed as stronger threat cues for nonhuman primates. However, it is still unclear whether spiders hold a special status in human perception. The current study explored to what extent spider pictures draw early visual attention [as assessed with early posterior negativity (EPN)] when compared with insects similar to spiders. To measure the EPN, participants watched a random rapid serial presentation of pictures, which consisted of two conditions: spider condition (spider, wasp, bumblebee, beetle) and snake condition (snake, bird). EPN amplitudes revealed no significant difference between spider, wasp, bumblebee, and beetle pictures, whereas EPN amplitudes were significantly larger for snake pictures relative to bird pictures. In addition, EPN amplitudes were significantly larger for snake pictures relative to spider pictures. These results suggest that the early visual attentional capture of animate objects is stronger for snakes, whereas spiders do not appear to hold special early attentional value.

Learning to avoid spiders: fear predicts performance, not competence.

PubMed

Luo, Xijia; Becker, Eni S; Rinck, Mike

2018-01-05

We used an immersive virtual environment to examine avoidance learning in spider-fearful participants. In 3 experiments, participants were asked to repeatedly lift one of 3 virtual boxes, under which either a toy car or a spider appeared and then approached the participant. Participants were not told that the probability of encountering a spider differed across boxes. When the difference was large (Exps. 1 and 2), spider-fearfuls learned to avoid spiders by lifting the few-spiders-box more often and the many-spiders-box less often than non-fearful controls did. However, they hardly managed to do so when the probability differences were small (Exp. 3), and they did not escape from threat more quickly (Exp. 2). In contrast to the observed performance differences, spider-fearfuls and non-fearfuls showed equal competence, that is comparable post-experimental knowledge about the probability to encounter spiders under the 3 boxes. The limitations and implications of the present study are discussed.

Trace element emissions from spontaneous combustion of gob piles in coal mines, Shanxi, China

USGS Publications Warehouse

Zhao, Y.; Zhang, Jiahua; Chou, C.-L.; Li, Y.; Wang, Z.; Ge, Y.; Zheng, C.

2008-01-01

The emissions of potentially hazardous trace elements from spontaneous combustion of gob piles from coal mining in Shanxi Province, China, have been studied. More than ninety samples of solid waste from gob piles in Shanxi were collected and the contents of twenty potentially hazardous trace elements (Be, F, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Sb, Hg, Tl, Pb, Th, and U) in these samples were determined. Trace element contents in solid waste samples showed wide ranges. As compared with the upper continental crust, the solid waste samples are significantly enriched in Se (20x) and Tl (12x) and are moderately enriched in F, As, Mo, Sn, Sb, Hg, Th, and U (2-5x). The solid waste samples are depleted in V, Cr, Mn, Co, Ni, Cu, and Zn. The solid waste samples are enriched in F, V, Mn, Cr, Co, Ni, Cu, Zn, Sb, Th, and U as compared with the Shanxi coals. Most trace elements are higher in the clinker than in the unburnt solid waste except F, Sn, and Hg. Trace element abundances are related to the ash content and composition of the samples. The content of F is negatively correlated with the ash content, while Pb is positively correlated with the ash. The concentrations of As, Mn, Zn, and Cd are highly positively correlated with Fe2O3 in the solid waste. The As content increases with increasing sulfur content in the solid waste. The trace element emissions are calculated for mass balance. The emission factors of trace elements during the spontaneous combustion of the gobs are determined and the trace element concentrations in the flue gas from the spontaneous combustion of solid waste are calculated. More than a half of F, Se, Hg and Pb are released to the atmosphere during spontaneous combustion. Some trace element concentrations in flue gas are higher than the national emission standards. Thus, gob piles from coal mining pose a serious environmental problem. ?? 2007 Elsevier B.V. All rights reserved.

Trace element contamination in feather and tissue samples from Anna’s hummingbirds

USGS Publications Warehouse

Mikoni, Nicole A.; Poppenga, Robert H.; Ackerman, Joshua T.; Foley, Janet E.; Hazlehurst, Jenny; Purdin, Güthrum; Aston, Linda; Hargrave, Sabine; Jelks, Karen; Tell, Lisa A.

2017-01-01

Trace element contamination (17 elements; Be, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Hg, Tl, and Pb) of live (feather samples only) and deceased (feather and tissue samples) Anna's hummingbirds (Calypte anna) was evaluated. Samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS; 17 elements) and atomic absorption spectrophotometry (Hg only). Mean plus one standard deviation (SD) was considered the benchmark, and concentrations above the mean + 1 SD were considered elevated above normal. Contour feathers were sampled from live birds of varying age, sex, and California locations. In order to reduce thermal impacts, minimal feathers were taken from live birds, therefore a novel method was developed for preparation of low mass feather samples for ICP-MS analysis. The study found that the novel feather preparation method enabled small mass feather samples to be analyzed for trace elements using ICP-MS. For feather samples from live birds, all trace elements, with the exception of beryllium, had concentrations above the mean + 1 SD. Important risk factors for elevated trace element concentrations in feathers of live birds were age for iron, zinc, and arsenic, and location for iron, manganese, zinc, and selenium. For samples from deceased birds, ICP-MS results from body and tail feathers were correlated for Fe, Zn, and Pb, and feather concentrations were correlated with renal (Fe, Zn, Pb) or hepatic (Hg) tissue concentrations. Results for AA spectrophotometry analyzed samples from deceased birds further supported the ICP-MS findings where a strong correlation between mercury concentrations in feather and tissue (pectoral muscle) samples was found. These study results support that sampling feathers from live free-ranging hummingbirds might be a useful, non-lethal sampling method for evaluating trace element exposure and provides a sampling alternative since their small body size limits traditional sampling of blood and tissues. The results from this study provide a benchmark for the distribution of trace element concentrations in feather and tissue samples from hummingbirds and suggests a reference mark for exceeding normal. Lastly, pollinating avian species are minimally represented in the literature as bioindicators for environmental trace element contamination. Given that trace elements can move through food chains by a variety of routes, our study indicates that hummingbirds are possible bioindicators of environmental trace element contamination.

Evaluation of trace element status of organic dairy cattle.

PubMed

Orjales, I; Herrero-Latorre, C; Miranda, M; Rey-Crespo, F; Rodríguez-Bermúdez, R; López-Alonso, M

2018-06-01

The present study aimed to evaluate trace mineral status of organic dairy herds in northern Spain and the sources of minerals in different types of feed. Blood samples from organic and conventional dairy cattle and feed samples from the respective farms were analysed by inductively coupled plasma mass spectrometry to determine the concentrations of the essential trace elements (cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), iodine (I), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se) and zinc (Zn)) and toxic trace elements (arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb)). Overall, no differences between organic and conventional farms were detected in serum concentrations of essential and toxic trace elements (except for higher concentrations of Cd on the organic farms), although a high level of inter-farm variation was detected in the organic systems, indicating that organic production greatly depends on the specific local conditions. The dietary concentrations of the essential trace elements I, Cu, Se and Zn were significantly higher in the conventional than in the organic systems, which can be attributed to the high concentration of these minerals in the concentrate feed. No differences in the concentrations of trace minerals were found in the other types of feed. Multivariate chemometric analysis was conducted to determine the contribution of different feed sources to the trace element status of the cattle. Concentrate samples were mainly associated with Co, Cu, I, Se and Zn (i.e. with the elements supplemented in this type of feed). However, pasture and grass silage were associated with soil-derived elements (As, Cr, Fe and Pb) which cattle may thus ingest during grazing.

Dietary exposure estimates of twenty-one trace elements from a Total Diet Study carried out in Pavia, Northern Italy.

PubMed

Turconi, Giovanna; Minoia, Claudio; Ronchi, Anna; Roggi, Carla

2009-04-01

The significant role of trace elements in human health is well documented. Trace elements are those compounds that need to be present in the human diet to maintain normal physiological functions. However, some microelements may become harmful at high levels of exposure, or, on the other hand, may give rise to malnutrition, when their exposure is too low. The aim of the present study was to provide a reliable estimate of the dietary exposure of twenty-one trace elements in a Northern Italian area. For this purpose, trace element analyses were undertaken on total diet samples collected from a university cafeteria in Pavia, Northern Italy. The average daily exposure for the adult people was calculated on the basis of food consumption frequency, portion size and trace element levels in foodstuffs. The mean exposure values satisfy the Italian RDA for all the essential trace elements, except for Fe exposure in females, and are well below the Provisional Tolerable Daily Intake for all the toxic compounds, showing that the probability of dietary exposure to health risks is overall small. As far as Fe exposure is concerned, a potential risk of anaemia in the female adult population should be considered, then studies aimed at evaluating the Fe nutritional status of adult Italian women should be addressed. In conclusion, while not excluding the possibility that the daily exposure determined in the present study may not be representative of the population as a whole, this study provides a good estimate of the Italian adult consumer exposure to twenty-one trace elements.

The effect of pasteurization on trace elements in donor breast milk.

PubMed

Mohd-Taufek, N; Cartwright, D; Davies, M; Hewavitharana, A K; Koorts, P; McConachy, H; Shaw, P N; Sumner, R; Whitfield, K

2016-10-01

Premature infants often receive pasteurized donor human milk when mothers are unable to provide their own milk. This study aims to establish the effect of the pasteurization process on a range of trace elements in donor milk. Breast milk was collected from 16 mothers donating to the milk bank at the Royal Brisbane and Women's Hospital. Samples were divided into pre- and post-pasteurization aliquots and were Holder pasteurized. Inductively coupled plasma mass spectrometry was used to analyze the trace elements zinc (Zn), copper (Cu), selenium (Se), manganese (Mn), iodine (I), iron (Fe), molybdenum (Mo) and bromine (Br). Differences in trace elements pre- and post-pasteurization were analyzed. No significant differences were found between the trace elements tested pre- and post-pasteurization, except for Fe (P<0.05). The median (interquartile range, 25 to 75%; μg l(-1)) of trace elements for pre- and post- pasteurization aliquots were-Zn: 1639 (888-4508), 1743 (878-4143), Cu: 360 (258-571), 367 (253-531), Se: 12.34 (11.73-17.60), 12.62 (11.94-16.64), Mn: (1.48 (1.01-1.75), 1.49 (1.11-1.75), I (153 (94-189), 158 (93-183), Fe (211 (171-277), 194 (153-253), Mo (1.46 (0.37-2.99), 1.42 (0.29-3.73) and Br (1066 (834-1443), 989 (902-1396). Pasteurization had minimal effect on several trace elements in donor breast milk but high levels of inter-donor variability of trace elements were observed. The observed decrease in the iron content of pasteurized donor milk is, however, unlikely to be clinically relevant.

Chemical analysis and geochemical associations in Devonian black shale core samples from Martin County, Kentucky; Carroll and Washington counties, Ohio; Wise County, Virginia; and Overton County, Tennessee

USGS Publications Warehouse

Leventhal, Joel S.

1979-01-01

Core samples from Devonian shales from five localities in the Appalachian Basin have been analyzed for major, minor, and trace constituents. The contents of major elements are rather similar; however, the minor constituents, organic C, S, PO4, and CO3, show variations by a factor of 10. Trace elements Mo, Ni, Cu, V, Co, U, Zn, Hg, As, and Mn show variations that can be related graphically and statistically to the minor constituents. Down-hole plots show the relationships most clearly. Mn is associated with CO3 content, the other trace elements are strongly Controlled by organic C. Amounts of organic C are generally in the range of 3-6 percent, and S is in the range of 2-5 percent. Trace-element amounts show the following general ranges (ppm, parts per million)- Co, 20-40; Cu,40-70; U, 10-40; As, 20-40, V, 150-300; Ni, 80-150; high values are as much as twice these values. The organic C was probably the concentrating agent, whereas the organic C and sulfide S created an environment for preservation or immobilization of trace elements. Closely spaced samples showing an abrupt transition in color from black to gray and gray to black shale show similar effects of trace-element changes, that is, black shale contains enhanced amounts of organic C and trace elements. Ratios of trace elements to organic C or sulfide S were relatively constant even though deposition rates varied from 10 to 300 meters in 5 million years.

Effects of attention manipulations on motivated attention to feared and nonfeared negative distracters in spider fear

PubMed Central

2013-01-01

Background When people view emotional and neutral pictures, the emotional pictures capture more attention than do neutral pictures. In support, studies with event-related potentials have shown that the early posterior negativity (EPN) and the late positive potential (LPP) to emotional versus neutral pictures are enhanced when pictures are attended. However, this motivated attention decreases when voluntary attention is directed away from the pictures. Most previous studies included only generally emotional pictures of either negative or positive valence. Because people with spider fear report intense fear of spiders, we examined whether directing attention away from emotional pictures at fixation decreases motivated attention less strongly for spiders than for generally negative distracters. Results We recorded event-related potentials from 128 channels to study whether manipulations of attention (i.e., spatial attention and perceptual load) decrease the EPN and the LPP to emotional distracters less strongly for spiders than for fear-irrelevant negative pictures in people with spider fear. Results confirmed that the EPN and the LPP to spiders (vs. neutral pictures) were particularly enhanced in participants with spider fear compared to participants without spider fear. When attention was directed away from the pictures, the EPN and the LPP to spiders (vs. neutral pictures) decreased similarly in fearful and nonfearful participants. Further, in fearful participants, the decrease in the EPN and the LPP was similar for spiders and for fear-irrelevant negative pictures. Conclusions Our findings suggest that for people with spider fear, directing attention away from emotional pictures at fixation decreases motivated attention to these distracters similarly for spiders as for fear-irrelevant negative pictures. These findings imply that attention to spiders in spider fear does not exceed the level of attention expected from the spider pictures’ high arousal and negative valence (i.e., their intrinsic motivated attention). PMID:24207058

Study on elemental fingerprint of traditional marine Chinese medicine oysters from Jiaozhou Bay, China

NASA Astrophysics Data System (ADS)

Zheng, Yongjun; Zheng, Kang; Li, Yantuan

2012-09-01

In order to investigate the relationship between the trace elements and the characteristics of the oysters, we analyzed the trace elements present in the germplasm of oysters from different producing areas in the Jiaozhou Bay. The element fingerprints were established to reflect the elemental characteristics of the oysters. Concentration patterns of the elements were deciphered by principle component analysis (PCA) and hierarchical cluster analysis (HCA). The six regions were discriminated with accuracy using HCA and PCA based on the concentration of 16 trace elements. The elements were viewed as characteristic elements of the oysters and the fingerprints of these elements could be used to distinguish the quality of the oysters.

The Phosphoria Formation at the Hot Springs Mine in Southeast Idaho; a source of selenium and other trace elements to surface water, ground water, vegetation, and biota

USGS Publications Warehouse

Piper, David Z.; Skorupa, J.P.; Presser, T.S.; Hardy, M.A.; Hamilton, S.J.; Huebner, M.; Gulbrandsen, R.A.

2000-01-01

Major-element oxides and trace elements in the Phosphoria Formation at the Hot Springs Mine, Idaho were determined by a series of techniques. In this report, we examine the distribution of trace elements between the different solid components aluminosilicates, apatite, organic matter, opal, calcite, and dolomite that largely make up the rocks. High concentrations of several trace elements throughout the deposit, for example, As, Cd, Se, Tl, and U, at this and previously examined sites have raised concern about their introduction into the environment via weathering and the degree to which mining and the disposal of mined waste rock from this deposit might be accelerating that process. The question addressed here is how might the partitioning of trace elements between these solid host components influence the introduction of trace elements into ground water, surface water, and eventually biota, via weathering? In the case of Se, it is partitioned into components that are quite labile under the oxidizing conditions of subaerial weathering. As a result, it is widely distributed throughout the environment. Its concentration exceeds the level of concern for protection of wildlife at virtually every trophic level.

HUMAN SCALP HAIR: AN ENVIRONMENTAL EXPOSURE INDEX FOR TRACE ELEMENTS. I. FIFTEEN TRACE ELEMENTS IN NEW YORK, N.Y. (1971-72)

EPA Science Inventory

Previous studies have revealed that hair trace element concentrations can reflect exposure in cases of frank poisoning and deficiency. Correlations have been found also in some populations living in regions where metallurgic processes are conducted. This study reports significant...

HUMAN SCALP HAIR: AN ENVIRONMENTAL EXPOSURE INDEX FOR TRACE ELEMENTS. II. SEVENTEEN TRACE ELEMENTS IN FOUR NEW JERSEY COMMUNITIES (1972)

EPA Science Inventory

Seventeen trace elements - arsenic (As), barium (Ba), boron (B), cadmium (Cd), chromium (Cr), copper (Cu), Iron (Fe), lead (Pb), lithium (Li), manganese (Mn), mercury (Hg), nickle (Ni), selenium (Se), silver (Ag), tin (Sn), vanadium (V), and zinc (Zn) - were measured in human sca...

Measurement of Trace Elements During the Development and Immune Response of Heliothis virescens Larvae

USDA-ARS?s Scientific Manuscript database

While many studies have examined the effect of microbial infections on the status of trace elements in mammalian tissues, similar studies have not been performed in insects. We used inductively coupled plasma-mass spectrometry (ICP-MS) to quantify changes in trace elements of Mg, Mn, Fe, Cu, Zn and ...

Transport of dissolved trace elements in surface runoff and leachate from a coastal plain soil after poultry litter application

USDA-ARS?s Scientific Manuscript database

The application of poultry (Gallus gallus domesticus) litter to agricultural soils may exacerbate losses of trace elements in runoff water, an emerging concern to water quality. We evaluated trace elements (arsenic, cadmium, copper, lead, manganese, mercury, selenium and zinc) in surface runoff and ...

Effect of trace element addition and increasing organic loading rates on the anaerobic digestion of cattle slaughterhouse wastewater.

PubMed

Schmidt, Thomas; McCabe, Bernadette K; Harris, Peter W; Lee, Seonmi

2018-05-18

In this study, anaerobic digestion of slaughterhouse wastewater with the addition of trace elements was monitored for biogas quantity, quality and process stability using CSTR digesters operated at mesophilic temperature. The determination of trace element concentrations was shown to be deficient in Fe, Ni, Co, Mn and Mo compared to recommendations given in the literature. Addition of these trace elements resulted in enhanced degradation efficiency, higher biogas production and improved process stability. Higher organic loading rates and lower hydraulic retention times were achieved in comparison to the control digesters. A critical accumulation of volatile fatty acids was observed at an organic loading rate of 1.82 g L -1  d -1 in the control compared to 2.36 g L -1  d -1 in the digesters with trace element addition. The improved process stability was evident in the final weeks of experimentation, in which control reactors produced 84% less biogas per day compared to the reactors containing trace elements. Copyright © 2018 Elsevier Ltd. All rights reserved.

Discrimination of trait-based characteristics by trace element bioaccumulation in riverine fishes

USGS Publications Warehouse

Short, T.M.; DeWeese, L.R.; Dubrovsky, N.M.

2008-01-01

Relations between tissue trace element concentrations and species traits were examined for 45 fish species to determine the extent to which trait-based characteristics accounted for relative differences among species in trace element bioaccumulation. Percentages of fish species correctly classified by discriminant analysis according to traits predicted by tissue trace element concentrations ranged from 72% to 87%. Tissue concentrations of copper, mercury, selenium, and zinc appeared to have the greatest overall influence on differentiating species according to trait characteristics. Discrimination of trait characteristics did not appear to be strongly influenced by local sources of trace elements in the streambed sediment. Bioaccumulation was greatest for those species classified as primarily detritivores, having relatively large adult body size, considered nonmigratory with respect to reproductive strategy, occurring mostly in large or variable size streams and rivers, preferring depositional areas within the stream channel, and preferring benthic rather than open-water habitats. Our findings provide evidence of the strong relationship between bioaccumulation of environmental trace elements and trait-based factors that influence contaminant exposure. ?? 2008 NRC.

[Measurement of the status of trace elements in cattle using liver biopsy samples].

PubMed

Ouweltjes, W; de Zeeuw, A C; Moen, A; Counotte, G H M

2007-02-01

Serum, plasma, or urine samples are usually used for the measurement of the trace elements copper; zinc, iron, selenium, because these samples are easy to obtain; however; these samples are not always appropriate. For example, it is not possible to measure molybdenum, the major antagonist of copper; in blood or urine. Therefore measurement of trace elements in liver tissue is considered the gold standard. For the assessment of selenium the method of choice remains determination of glutathion peroxidase in erythrocytes and for the assessment of magnesium determination of magnesium in urine. We determined the accuracy and repeatability of measuring trace elements in liver biopsies and whole liver homogenates. The levels of trace elements measured were similar in both preparations (92% agreement). Liver biopsy in live animals is a relatively simple procedure but not common in The Netherlands. Reference levels of trace elements, classified as too low, low, adequate, high, and too high, were established on the basis of our research and information in the literature. In a second study we investigated the practical aspects of obtaining liver tissue samples and their use. Samples were collected from cattle on a commercial dairy farm. Liver biopsy provided additional information to that obtained from serum and urine samples. We prepared a biopsy protocol and a test package, which we tested on 14 farms where an imbalance of trace minerals was suspected. Biopsy samples taken from 4 to 6 animals revealed extreme levels of trace elements.

Trace elements are associated with urinary 8-hydroxy-2'-deoxyguanosine level: a case study of college students in Guangzhou, China.

PubMed

Lu, Shaoyou; Ren, Lu; Fang, Jianzhang; Ji, Jiajia; Liu, Guihua; Zhang, Jianqing; Zhang, Huimin; Luo, Ruorong; Lin, Kai; Fan, Ruifang

2016-05-01

Many trace heavy elements are carcinogenic and increase the incidence of cancer. However, a comprehensive study of the correlation between multiple trace elements and DNA oxidative damage is still lacking. The aim of this study is to investigate the relationships between the body burden of multiple trace elements and DNA oxidative stress in college students in Guangzhou, China. Seventeen trace elements in urine samples were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative stress, was also measured using liquid chromatography tandem mass spectrometer (LC-MS/MS). The concentrations of six essential elements including manganese (Mn), copper (Cu), nickel (Ni), selenium (Se), strontium (Sr), and molybdenum (Mo), and five non-essential elements including arsenic (As), cadmium (Cd), aluminum (Al), stibium (Sb), and thallium (Tl), were found to be significantly correlated with urinary 8-OHdG levels. Moreover, urinary levels of Ni, Se, Mo, As, Sr, and Tl were strongly significantly correlated with 8-OHdG (P < 0.01) concentration. Environmental exposure and dietary intake of these trace elements may play important roles in DNA oxidative damage in the population of Guangzhou, China.

Diel cycling of trace elements in streams draining mineralized areas: a review

USGS Publications Warehouse

Gammons, Christopher H.; Nimick, David A.; Parker, Stephen R.

2015-01-01

Many trace elements exhibit persistent diel, or 24-h, concentration cycles in streams draining mineralized areas. These cycles can be caused by various physical and biogeochemical mechanisms including streamflow variation, photosynthesis and respiration, as well as reactions involving photochemistry, adsorption and desorption, mineral precipitation and dissolution, and plant assimilation. Iron is the primary trace element that exhibits diel cycling in acidic streams. In contrast, many cationic and anionic trace elements exhibit diel cycling in near-neutral and alkaline streams. Maximum reported changes in concentration for these diel cycles have been as much as a factor of 10 (988% change in Zn concentration over a 24-h period). Thus, monitoring and scientific studies must account for diel trace-element cycling to ensure that water-quality data collected in streams appropriately represent the conditions intended to be studied.

Total-reflection X-ray fluorescence studies of trace elements in biomedical samples

NASA Astrophysics Data System (ADS)

Kubala-Kukuś, A.; Braziewicz, J.; Pajek, M.

2004-08-01

Application of the total-reflection X-ray fluorescence (TXRF) analysis in the studies of trace element contents in biomedical samples is discussed in the following aspects: (i) a nature of trace element concentration distributions, (ii) censoring approach to the detection limits, and (iii) a comparison of two sets of censored data. The paper summarizes the recent results achieved in this topics, in particular, the lognormal, or more general logstable, nature of concentration distribution of trace elements, the random left-censoring and the Kaplan-Meier approach accounting for detection limits and, finally, the application of the logrank test to compare the censored concentrations measured for two groups. These new aspects, which are of importance for applications of the TXRF in different fields, are discussed here in the context of TXRF studies of trace element in various samples of medical interest.

Spider Webs and Silks.

ERIC Educational Resources Information Center

Vollrath, Fritz

1992-01-01

Compares the attributes of the silk from spiders with those of the commercially harvested silk from silkworms. Discusses the evolution, design, and effectiveness of spider webs; the functional mechanics of the varieties of silk that can be produced by the same spider; and the composite, as well as molecular, structure of spider silk thread. (JJK)

Science Education Resources on the Web--Spiders.

ERIC Educational Resources Information Center

Thirunarayanan, M. O.

1997-01-01

Lists Web sites containing information on spiders and offers brief descriptions of the information available at those sites. The 11 sites provide information on taxonomy of spiders, anatomy, different ways spiders use silk, Internet mailing lists, folk literature and art, bibliographies, night collection, and spiders commonly found in the state of…

Non-webbuilding spiders: prey specialists or generalists?

PubMed

Nentwig, Wolfgang

1986-07-01

Feeding experiments were performed with seven species of non-webbuilding spiders and a variety of prey taxa. Some species were generally polyphagous whereas other spiders restricted their prey to a few groups. At one end of the spectrum of prey specialization the thomisid Misumena vatia is limited to a few taxa of possible prey (Table 1). The literature of prey records of non-webbuilding spiders is reviewed (Table 2) with special emphasis on oligophagous or monophagous spiders. Monophagous spiders are generally rare and have specialized on only a few prey taxa: social insects (ants, bees, termites) and spiders.

When spiders appear suddenly: spider-phobic patients are distracted by task-irrelevant spiders.

PubMed

Gerdes, Antje B M; Alpers, Georg W; Pauli, Paul

2008-02-01

Fear is thought to facilitate the detection of threatening stimuli. Few studies have examined the effects of task-irrelevant phobic cues in search tasks that do not involve semantic categorization. In a combined reaction time and eye-tracking experiment we investigated whether peripheral visual cues capture initial attention and distract from the execution of goal-directed eye movements. Twenty-one spider-phobic patients and 21 control participants were instructed to search for a color singleton while ignoring task-irrelevant abrupt-onset distractors which contained either a small picture of a spider (phobic), a flower (non-phobic, but similar to spiders in shape), a mushroom (non-phobic, and not similar to spiders in shape), or no picture. As expected, patients' reaction times were longer on trials with spider distractors. However, eye movements revealed that this was not due to attentional capture by spider distractors; patients more often fixated on all distractors with pictures, but their reaction times were delayed by longer fixation durations on spider distractors. These data do not support automatic capture of attention by phobic cues but suggest that phobic patients fail to disengage attention from spiders.

High-performance spider webs: integrating biomechanics, ecology and behaviour

PubMed Central

Harmer, Aaron M. T.; Blackledge, Todd A.; Madin, Joshua S.; Herberstein, Marie E.

2011-01-01

Spider silks exhibit remarkable properties, surpassing most natural and synthetic materials in both strength and toughness. Orb-web spider dragline silk is the focus of intense research by material scientists attempting to mimic these naturally produced fibres. However, biomechanical research on spider silks is often removed from the context of web ecology and spider foraging behaviour. Similarly, evolutionary and ecological research on spiders rarely considers the significance of silk properties. Here, we highlight the critical need to integrate biomechanical and ecological perspectives on spider silks to generate a better understanding of (i) how silk biomechanics and web architectures interacted to influence spider web evolution along different structural pathways, and (ii) how silks function in an ecological context, which may identify novel silk applications. An integrative, mechanistic approach to understanding silk and web function, as well as the selective pressures driving their evolution, will help uncover the potential impacts of environmental change and species invasions (of both spiders and prey) on spider success. Integrating these fields will also allow us to take advantage of the remarkable properties of spider silks, expanding the range of possible silk applications from single threads to two- and three-dimensional thread networks. PMID:21036911

Spider-mediated flux of PCBs from contaminated sediments to terrestrial ecosystems and potential risks to arachnivorous birds

USGS Publications Warehouse

Walters, D.M.; Mills, M.A.; Fritz, K.M.; Raikow, D.F.

2010-01-01

We investigated aquatic insect utilization and PCB exposure in riparian spiders at the Lake Hartwell Superfund site (Clemson, SC). We sampled sediments, adult chironomids, terrestrial insects, riparian spiders (Tetragnathidae, Araneidae, and Mecynogea lemniscata), and upland spiders (Araneidae) along a sediment contamination gradient. Stable isotopes (?13C, ? 15N) indicated that riparian spiders primarily consumed aquatic insects whereas upland spiders consumed terrestrial insects. PCBs in chironomids (mean 1240 ng/g among sites) were 2 orders of magnitude higher than terrestrial insects (15.2 ng/g), similar to differences between riparian (820?2012 ng/g) and upland spiders (30 ng/g). Riparian spider PCBs were positively correlated with sediment concentrations for all taxa (r2 = 0.44?0.87). We calculated spider-based wildlife values (WVs, the minimum spider PCB concentrations causing physiologically significant doses in consumers) to assess exposure risks for arachnivorous birds. Spider concentrations exceeded WVs for most birds at heavily contaminated sites and were ?14-fold higher for the most sensitive species (chickadee nestlings, Poecile spp.). Spiders are abundant and ubiquitous in riparian habitats, where they depend on aquatic insect prey. These traits, along with the high degree of spatial correlation between spider and sediment concentrations we observed, suggest that they are model indicator species for monitoring contaminated sediment sites and assessing risks associated with contaminant flux into terrestrial ecosystems. ?? This article not subject to U.S. Copyright. Published 2009 by the American Chemical Society.

An insect-feeding guild of carnivorous plants and spiders: does optimal foraging lead to competition or facilitation?

PubMed

Crowley, Philip H; Hopper, Kevin R; Krupa, James J

2013-12-01

Carnivorous plants and spiders, along with their prey, are main players in an insect-feeding guild found on acidic, poorly drained soils in disturbed habitat. Darwin's notion that these plants must actively attract the insects they capture raises the possibility that spiders could benefit from proximity to prey hotspots created by the plants. Alternatively, carnivorous plants and spiders may deplete prey locally or (through insect redistribution) more widely, reducing each other's gain rates from predation. Here, we formulate and analyze a model of this guild, parameterized for carnivorous sundews and lycosid spiders, under assumptions of random movement by insects and optimal foraging by predators. Optimal foraging here involves gain maximization via trap investment (optimal web sizes and sundew trichome densities) and an ideal free distribution of spiders between areas with and without sundews. We find no facilitation: spiders and sundews engage in intense exploitation competition. Insect attraction by plants modestly increases sundew gain rates but slightly decreases spider gain rates. In the absence of population size structure, optimal spider redistribution between areas with and without sundews yields web sizes that are identical for all spiders, regardless of proximity to sundews. Web-building spiders have higher gain rates than wandering spiders in this system at high insect densities, but wandering spiders have the advantage at low insect densities. Results are complex, indicating that predictions to be tested empirically must be based on careful quantitative assessment.

Atmospheric Deposition of Trace Elements in Ombrotrophic Peat as a Result of Anthropic Activities

NASA Astrophysics Data System (ADS)

Fabio Lourençato, Lucio; Cabral Teixeira, Daniel; Vieira Silva-Filho, Emmanoel

2014-05-01

Ombrotrophic peat can be defined as a soil rich in organic matter, formed from the partial decomposition of vegetable organic material in a humid and anoxic environment, where the accumulation of material is necessarily faster than the decomposition. From the physical-chemical point of view, it is a porous and highly polar material with high adsorption capacity and cation exchange. The high ability of trace elements to undergo complexation by humic substances happens due to the presence of large amounts of oxygenated functional groups in these substances. Since the beginning of industrialization human activities have scattered a large amount of trace elements in the environment. Soil contamination by atmospheric deposition can be expressed as a sum of site contamination by past/present human activities and atmospheric long-range transport of trace elements. Ombrotrophic peat records can provide valuable information about the entries of trace metals into the atmosphere and that are subsequently deposited on the soil. These trace elements are toxic, non-biodegradable and accumulate in the food chain, even in relatively low quantities. Thus studies on the increase of trace elements in the environment due to human activities are necessary, particularly in the southern hemisphere, where these data are scarce. The aims of this study is to evaluate the concentrations of mercury in ombrotrophic peat altomontanas coming from atmospheric deposition. The study is conducted in the Itatiaia National Park, Brazilian conservation unit, situated between the southeastern state of Rio de Janeiro, São Paulo and Minas Gerais. An ombrotrophic peat core is being sampled in altitude (1980m), to measure the trace elements concentrations of this material. As it is conservation area, the trace elements found in the samples is mainly from atmospheric deposition, since in Brazil don't exist significant lithology of trace elements. The samples are characterized by organic matter content which is determined by calcination and pH. For the determination of mercury, an aliquot of 10 mL of sample with 5 mL of the reducing agent 2 % SnCl2, purged with air by atomic absorption spectrophotometry by cold vapor, EAAVF is being used. The determination of other trace elements (Zn, Cd and Pb) is analyzed by flame atomic absorption spectroscopy (FAAS).

Investigation of the roles of trace elements during hepatitis C virus infection using protein-protein interactions and a shortest path algorithm.

PubMed

Zhu, LiuCun; Chen, XiJia; Kong, Xiangyin; Cai, Yu-Dong

2016-11-01

Hepatitis is a type of infectious disease that induces inflammation of the liver without pinpointing a particular pathogen or pathogenesis. Type C hepatitis, as a type of hepatitis, has been reported to induce cirrhosis and hepatocellular carcinoma within a very short amount of time. It is a great threat to human health. Some studies have revealed that trace elements are associated with infection with and immune rejection against hepatitis C virus (HCV). However, the mechanism underlying this phenomenon is still unclear. In this study, we aimed to expand our knowledge of this phenomenon by designing a computational method to identify genes that may be related to both HCV and trace element metabolic processes. The searching procedure included three stages. First, a shortest path algorithm was applied to a large network, constructed by protein-protein interactions, to identify potential genes of interest. Second, a permutation test was executed to exclude false discoveries. Finally, some rules based on the betweenness and associations between candidate genes and HCV and trace elements were built to select core genes among the remaining genes. 12 lists of genes, corresponding to 12 types of trace elements, were obtained. These genes are deemed to be associated with HCV infection and trace elements metabolism. The analyses indicate that some genes may be related to both HCV and trace element metabolic processes, further confirming the associations between HCV and trace elements. The method was further tested on another set of HCV genes, the results indicate that this method is quite robustness. The newly found genes may partially reveal unknown mechanisms between HCV infection and trace element metabolism. This article is part of a Special Issue entitled "System Genetics" Guest Editor: Dr. Yudong Cai and Dr. Tao Huang. Copyright © 2016 Elsevier B.V. All rights reserved.

Open-water and under-ice seasonal variations in trace element content and physicochemical associations in fluvial bed sediment.

PubMed

Doig, Lorne E; Carr, Meghan K; Meissner, Anna G N; Jardine, Tim D; Jones, Paul D; Bharadwaj, Lalita; Lindenschmidt, Karl-Erich

2017-11-01

Across the circumpolar world, intensive anthropogenic activities in the southern reaches of many large, northward-flowing rivers can cause sediment contamination in the downstream depositional environment. The influence of ice cover on concentrations of inorganic contaminants in bed sediment (i.e., sediment quality) is unknown in these rivers, where winter is the dominant season. A geomorphic response unit approach was used to select hydraulically diverse sampling sites across a northern test-case system, the Slave River and delta (Northwest Territories, Canada). Surface sediment samples (top 1 cm) were collected from 6 predefined geomorphic response units (12 sites) to assess the relationships between bed sediment physicochemistry (particle size distribution and total organic carbon content) and trace element content (mercury and 18 other trace elements) during open-water conditions. A subset of sites was resampled under-ice to assess the influence of season on these relationships and on total trace element content. Concentrations of the majority of trace elements were strongly correlated with percent fines and proxies for grain size (aluminum and iron), with similar trace element grain size/grain size proxy relationships between seasons. However, finer materials were deposited under ice with associated increases in sediment total organic carbon content and the concentrations of most trace elements investigated. The geomorphic response unit approach was effective at identifying diverse hydrological environments for sampling prior to field operations. Our data demonstrate the need for under-ice sampling to confirm year-round consistency in trace element-geochemical relationships in fluvial systems and to define the upper extremes of these relationships. Whether contaminated or not, under-ice bed sediment can represent a "worst-case" scenario in terms of trace element concentrations and exposure for sediment-associated organisms in northern fluvial systems. Environ Toxicol Chem 2017;36:2916-2924. © 2017 SETAC. © 2017 SETAC.

Reconnaissance of Soil, Ground Water, and Plant Contamination at an Abandoned Oilfield-Service Site near Shawnee, Oklahoma, 2005-2006

USGS Publications Warehouse

Mashburn, Shana L.; Smith, S. Jerrod

2007-01-01

The U.S. Geological Survey, in cooperation with the Absentee Shawnee Tribe of Oklahoma, began a reconnaissance study of a site in Pottawatomie County, Oklahoma, in 2005 by testing soil, shallow ground water, and plant material for the presence of trace elements and semivolatile organic compounds. Chemical analysis of plant material at the site was investigated as a preliminary tool to determine the extent of contamination at the site. Thirty soil samples were collected from 15 soil cores during October 2005 and analyzed for trace elements and semivolatile organic compounds. Five small-diameter, polyvinyl-chloride-cased wells were installed and ground-water samples were collected during December 2005 and May 2006 and analyzed for trace elements and semivolatile organic compounds. Thirty Johnsongrass samples and 16 Coralberry samples were collected during September 2005 and analyzed for 53 constituents, including trace elements. Results of the soil, ground-water, and plant data indicate that the areas of trace element and semivolatile organic compound contamination are located in the shallow (A-horizon) soils near the threading barn. Most of the trace-element concentrations in the soils on the study site were either similar to or less than trace-element concentrations in background soils. Several trace elements and semivolatile organic compounds exceeded the U.S. Environmental Protection Agency, Region 6, Human Health Medium-Specific Screening Levels 2007 for Tap Water, Residential Soils, Industrial Indoor Soils, and Industrial Outdoor Soils. There was little or no correlation between the plant and soil sample concentrations and the plant and ground-water concentrations based on the current sample size and study design. The lack of correlation between trace-element concentrations in plants and soils, and plants and ground water indicate that plant sampling was not useful as a preliminary tool to assess contamination at the study site.

Marine Bioinorganic Chemistry: The Role of Trace Metals in the Oceanic Cycles of Major Nutrients

NASA Astrophysics Data System (ADS)

Morel, F. M. M.; Milligan, A. J.; Saito, M. A.

2003-12-01

The bulk of living biomass is chiefly made up of only a dozen "major" elements - carbon, hydrogen, oxygen, nitrogen, phosphorus, sodium, potassium, chlorine, calcium, magnesium, sulfur (and silicon in diatoms) - whose proportions vary within a relatively narrow range in most organisms. A number of trace elements, particularly first row transition metals - manganese, iron, nickel, cobalt, copper, and zinc - are also "essential" for the growth of organisms. At the molecular level, the chemical mechanisms by which such elements function as active centers or structural factors in enzymes and by which they are accumulated and stored by organisms is the central topic of bioinorganic chemistry. At the scale of ocean basins, the interplay of physical, chemical, and biological processes that govern the cycling of biologically essential elements in seawater is the subject of marine biogeochemistry. For those interested in the growth of marine organisms, particularly in the one-half of the Earth's primary production contributed by marine phytoplankton, bioinorganic chemistry and marine biogeochemistry are critically linked by the extraordinary paucity of essential trace elements in surface seawater, which results from their biological utilization and incorporation in sinking organic matter. How marine organisms acquire elements that are present at nano- or picomolar concentrations in surface seawater; how they perform critical enzymatic functions when necessary metal cofactors are almost unavailable are the central topics of "marine bioinorganic chemistry." The central aim of this field is to elucidate at the molecular level the metal-dependent biological processes involved in the major biogeochemical cycles.By examining the solutions that emerged from the problems posed by the scarcity of essential trace elements, marine bioinorganic chemists bring to light hitherto unknown ways to take up or utilize trace elements, new molecules, and newer "essential" elements. Focusing on molecular mechanisms involved in such processes as inorganic carbon fixation, organic carbon respiration, or nitrogen transformation, they explain how the cycles of trace elements are critically linked to those of major nutrients such as carbon or nitrogen. But we have relatively little understanding of the binding molecules and the enzymes that mediate the biochemical role of trace metals in the marine environment. In this sense, this chapter is more a "preview" than a review of the field of marine bioinorganic chemistry. To exemplify the concepts and methods of this field, we have chosen to focus on one of its most important topics: the potentially limiting role of trace elements in primary marine production. As a result we center our discussion on particular subsets of organisms, biogeochemical cycles, and trace elements. Our chief actors are marine phytoplankton, particularly eukaryotes, while heterotrophic bacteria make only cameo appearances. The biogeochemical cycles that will serve as our plot are those of the elements involved in phytoplankton growth, the major algal nutrients - carbon, nitrogen, phosphorus, and silicon - leaving aside, e.g., the interesting topic of the marine sulfur cycle. Seven trace metals provide the intrigue: manganese, iron, nickel, cobalt, copper, zinc, and cadmium. But several other trace elements such as selenium, vanadium, molybdenum, and tungsten (and, probably, others not yet identified) will assuredly add further twists in future episodes.We begin this chapter by discussing what we know of the concentrations of trace elements in marine microorganisms and of the relevant mechanisms and kinetics of trace-metal uptake. We then review the biochemical role of trace elements in the marine cycles of carbon, nitrogen, phosphorus, and silicon. Using this information, we examine the evidence, emanating from both laboratory cultures and field measurements, relevant to the mechanisms and the extent of control by trace metals of marine biogeochemical cycles. Before concluding with a wistful glimpse of the future of marine bioinorganic chemistry we discuss briefly some paleoceanographic aspects of this new field: how the chemistry of the planet "Earth" - particularly the concentrations of trace elements in the oceans - has evolved since its origin, chiefly as a result of biological processes and how the evolution of life has, in turn, been affected by the availability of essential trace elements.

PIXE analysis of ancient Chinese Qing dynasty porcelain

NASA Astrophysics Data System (ADS)

Cheng, Huansheng; He, Wenquan; Tang, Jiayong; Yang, Fujia; Wang, Jianhua

1996-09-01

The major and minor chemical compositions and trace element content of white glaze made in Qing dynasty at kuan kiln have been determined by PIXE. Experimental results show that trace element contents RbSrZr are useful to distinguish the place of production of ancient porcelain. In the porcelain from different kilns situated in a same province, the trace element contents can be different from each other. Determining and comparing the major and minor compositions and trace elemental concentrations in white glaze by PIXE technique, we can distinguish a precious Qing dynasty porcelain made at kuan kiln from a fake.

Water-quality assessment of part of the Upper Mississippi River Basin, Minnesota and Wisconsin: Trace elements in streambed sediment and fish livers, 1995-96

USGS Publications Warehouse

Kroening, Sharon E.; Fallon, James D.; Lee, Kathy E.

2000-01-01

In fish livers, all of the trace elements analyzed were detected except antimony, beryllium, cobalt, and uranium. Trace element concentrations in fish livers generally did not show any pronounced patterns. Ranges for concentrations of arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc were similar to those measured in 20 other NAWQA studies across the United States. Cadmium concentrations in fish livers were moderately correlated to fish length and weight. There were no relations between trace element concentrations in fish livers and streambed sediment.

Paleoproterozoic mafic dike swarms of the Dunhuang Block: record of initial breakup of the Columbia suppercontinent?

NASA Astrophysics Data System (ADS)

Ye, X. T.; Zhang, C. L.

2017-12-01

Mafic dike swarms have been described as igneous record related to the breakup and dispersal of continental masses. Studying their origin and distribution are thus important for the understanding of the regional magmatic-tectonic evolution during the late Paleoproterozoic and possible relationship between the Dunhuang Block and the Columbia supercontinent. Here detail petrolography, zircon U-Pb age, and geochemistry are presented of the mafic dikes in the Dunhuang Block. The mafic dikes are tabular, E-W trending, mainly consist of the diabase and diabasic gabbro. Fine-grained gabbroic rocks are seen in the center of some of the thick dikes. These rocks are massive, showing ophitic texture with tholeiitic affinity and dominated by basaltic compositions. Zircon SHRIMP U-Pb dating of these dykes yields emplacement age of 1867 ± 8 Ma. According to their geochemical features, the mafic dikes are subdivided into three groups (G1, G2, and G3). G1 dikes have low SiO2 (47.80-48.82%), high MgO (6.00-8.44%), Cr (92-170 ppm), and Ni (46-106 ppm), indicating that they were not significantly affected by fractional crystallization or crustal assimilations. This result is consistent with their insignificant Nb-Ta troughs on the incompatible elements spider diagrams. Compared to G1 dikes, G2 dikes show higher SiO2 (49.18-49.76%), lower MgO (4.92-5.23%), Cr (35-44 ppm), and Ni (72-82 ppm). They show moderate Nb-Ta depletion on the primitive mantle normalized spider diagrams. Compared with G1 and G2 dikes, G3 dikes exhibit lowest SiO2 (46.05-49.76%) and MgO (4.07-4.37%) and highest TiO2 (3.38-3.50%), P2O5 (1.81-1.94%), and total alkalis (5.04-5.73%). In addition, G3 dikes have higher total REE abundances and extremely depleted in Nb-Ta with Nb/La ratios from 0.25 to 0.27. Although these mafic dikes show different REE and trace element patterns, the element signatures (Nb/La, Th/La, Ce/Nb, Th/Nb, and (Zr/Nb)N ratios) are similar to those of the intraplate basalts, while different from the volcanic arc basalts or mid-ocean ridge basalts. This may suggest that the primitive magmas of G1, G2, and G3 were derived from an OIB-like mantle source, which may be related to the plume magmatism or to an intracontinental extension setting, associated with the initial breakup of the Columbia suppercontinent.

The effect of acidified sample storage time on the determination of trace element concentration in ice cores by ICP-SFMS

NASA Astrophysics Data System (ADS)

Uglietti, C.; Gabrielli, P.; Lutton, A.; Olesik, J.; Thompson, L. G.

2012-12-01

Trace elements in micro-particles entrapped in ice cores are a valuable proxy of past climate and environmental variations. Inductively coupled plasma sector field mass spectrometry (ICP-SFMS) is generally recognized as a sensitive and accurate technique for the quantification of ultra-trace element concentrations in ice cores. Usually, ICP-SFMS analyses of ice core samples are performed by melting and acidifying aliquots. Acidification is important to transfer trace elements from particles into solution by partial and/or complete dissolution. Only elements in solution and in sufficiently small particles will be vaporized and converted to elemental ions in the plasma for detection by ICP-SFMS. However, experimental results indicate that differences in acidified sample storage time at room temperature may lead to the recovery of different trace element fractions. Moreover, different lithologies of the relatively abundant crustal material entrapped in the ice matrix could also influence the fraction of trace elements that are converted into elemental ions in the plasma. These factors might affect the determination of trace elements concentrations in ice core samples and hamper the comparison of results obtained from ice cores from different locations and/or epochs. In order to monitor the transfer of elements from particles into solution in acidified melted ice core samples during storage, a test was performed on sections from nine ice cores retrieved from low latitude drilling sites around the world. When compared to ice cores from polar regions, these samples are characterized by a relative high content of micro-particles that may leach trace elements into solution differently. Of the nine ice cores, five are from the Tibetan Plateau (Dasuopu, Guliya, Naimonanyi, Puruogangri and Dunde), two from the Andes (Quelccaya and Huascaran), one from Africa (Kilimanjaro) and one from the Eastern Alps (Ortles). These samples were decontaminated by triple rinsing, melted and stored in pre-cleaned low-density polyethylene bottles, and kept frozen until acidification (2% v/v ultra-pure HNO3). Determination of twenty trace elements (Ag, Al, As, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Pb, Rb, Sb, Sn, Ti, Tl, U, V, and Zn) was repeated at different times after acidification using the same aliquot. Analyses show a mean increase of 40-50% in trace element concentration in all the samples during the first 15 days of storage after acidification, except Al, Fe, V and Cr, which show a larger increase (90-100%). After 15 days the trace element concentrations reach generally stable values (with small increases within measurement uncertainty), except for the Naimonanyi and Kilimanjaro samples which continue to increase. In contrast, Ag concentration decreases after one week, likely due to its low stability in the acidified solution that may depend on the Cl- concentration. We froze the samples 43 days after the acidification. After two weeks the samples were melted and re-analyzed by ICP-SFMS in two different laboratories as an inter-calibration exercise. The results show a good correspondence between the measured concentrations determined by the two instruments and a consistent additional increase of 20-30% of measured trace element concentrations in almost all samples.

Trace element storage capacity of sediments in dead Posidonia oceanica mat from a chronically contaminated marine ecosystem.

PubMed

Di Leonardo, Rossella; Mazzola, Antonio; Cundy, Andrew B; Tramati, Cecilia Doriana; Vizzini, Salvatrice

2017-01-01

Posidonia oceanica mat is considered a long-term bioindicator of contamination. Storage and sequestration of trace elements and organic carbon (C org ) were assessed in dead P. oceanica mat and bare sediments from a highly polluted coastal marine area (Augusta Bay, central Mediterranean). Sediment elemental composition and sources of organic matter have been altered since the 1950s. Dead P. oceanica mat displayed a greater ability to bury and store trace elements and C org than nearby bare sediments, acting as a long-term contaminant sink over the past 120 yr. Trace elements, probably associated with the mineral fraction, were stabilized and trapped despite die-off of the overlying P. oceanica meadow. Mat deposits registered historic contamination phases well, confirming their role as natural archives for recording trace element trends in marine coastal environments. This sediment typology is enriched with seagrass-derived refractory organic matter, which acts mainly as a diluent of trace elements. Bare sediments showed evidence of inwash of contaminated sediments via reworking; more rapid and irregular sediment accumulation; and, because of the high proportions of labile organic matter, a greater capacity to store trace elements. Through different processes, both sediment typologies represent a repository for chemicals and may pose a risk to the marine ecosystem as a secondary source of contaminants in the case of sediment dredging or erosion. Environ Toxicol Chem 2017;36:49-58. © 2016 SETAC. © 2016 SETAC.

Aluminum, iron, lead, cadmium, copper, zinc, chromium, magnesium, strontium, and calcium content in bone of end-stage renal failure patients.

PubMed

D'Haese, P C; Couttenye, M M; Lamberts, L V; Elseviers, M M; Goodman, W G; Schrooten, I; Cabrera, W E; De Broe, M E

1999-09-01

Little is known about trace metal alterations in the bones of dialysis patients or whether particular types of renal osteodystrophy are associated with either increased or decreased skeletal concentrations of trace elements. Because these patients are at risk for alterations of trace elements as well as for morbidity from skeletal disorders, we measured trace elements in bone of patients with end-stage renal disease. We analyzed bone biopsies of 100 end-stage renal failure patients enrolled in a hemodialysis program. The trace metal contents of bone biopsies with histological features of either osteomalacia, adynamic bone disease, mixed lesion, normal histology, or hyperparathyroidism were compared with each other and with the trace metal contents of bone of subjects with normal renal function. Trace metals were measured by atomic absorption spectrometry. The concentrations of aluminum, chromium, and cadmium were increased in bone of end-stage renal failure patients. Comparing the trace metal/calcium ratio, significantly higher values were found for the bone chromium/calcium, aluminum/calcium, zinc/calcium, magnesium/calcium, and strontium/calcium ratios. Among types of renal osteodystrophy, increased bone aluminum, lead, and strontium concentrations and strontium/calcium and aluminum/calcium ratios were found in dialysis patients with osteomalacia vs the other types of renal osteodystrophy considered as one group. Moreover, the concentrations of several trace elements in bone were significantly correlated with each other. Bone aluminum was correlated with the time on dialysis, whereas bone iron, aluminum, magnesium, and strontium tended to be associated with patient age. Bone trace metal concentrations did not depend on vitamin D intake nor on the patients' gender. The concentration of several trace elements in bone of end-stage renal failure patients is disturbed, and some of the trace metals under study might share pathways of absorption, distribution, and accumulation. The clinical significance of the increased/decreased concentrations of several trace elements other than aluminum in bone of dialysis patients deserves further investigation.

Trace element levels and cognitive function in rural elderly Chinese.

PubMed

Gao, Sujuan; Jin, Yinlong; Unverzagt, Frederick W; Ma, Feng; Hall, Kathleen S; Murrell, Jill R; Cheng, Yibin; Shen, Jianzhao; Ying, Bo; Ji, Rongdi; Matesan, Janetta; Liang, Chaoke; Hendrie, Hugh C

2008-06-01

Trace elements are involved in metabolic processes and oxidation-reduction reactions in the central nervous system and could have a possible effect on cognitive function. The relationship between trace elements measured in individual biological samples and cognitive function in an elderly population had not been investigated extensively. The participant population is part of a large cohort study of 2000 rural elderly Chinese persons. Six cognitive assessment tests were used to evaluate cognitive function in this population, and a composite score was created to represent global cognitive function. Trace element levels of aluminum, calcium, cadmium, copper, iron, lead, and zinc were analyzed in plasma samples of 188 individuals who were randomly selected and consented to donating fasting blood. Analysis of covariance models were used to assess the association between each trace element and the composite cognitive score adjusting for demographics, medical history of chronic diseases, and the apolipoprotein E (APOE) genotype. Three trace elements-calcium, cadmium, and copper-were found to be significantly related to the composite cognitive score. Increasing plasma calcium level was associated with higher cognitive score (p <.0001). Increasing cadmium and copper, in contrast, were significantly associated with lower composite score (p =.0044 and p =.0121, respectively). Other trace elements did not show significant association with the composite cognitive score. Our results suggest that calcium, cadmium, and copper may be associated with cognitive function in the elderly population.

Epidemiology of trace elements deficiencies in Belgian beef and dairy cattle herds.

PubMed

Guyot, Hugues; Saegerman, Claude; Lebreton, Pascal; Sandersen, Charlotte; Rollin, Frédéric

2009-01-01

Selenium (Se), iodine (I), zinc (Zn) and copper (Cu) deficiencies in cattle have been reported in Europe. These deficiencies are often associated with diseases. The aim of the study was to assess trace element status in Belgian cattle herds showing pathologies and to compare them to healthy cattle herds. Eighty-two beef herds with pathologies, 11 healthy beef herds, 65 dairy herds with pathologies and 20 healthy dairy herds were studied during barn period. Blood and/or milk samples were taken in healthy animals. Plasma Zn, Cu, inorganic I (PII) and activity of glutathione peroxidase in erythrocytes (GPX) were assayed. In milk, I concentration was measured. Data about pathologies and nutrition in the herds were collected. According to defined thresholds, it appeared that a large proportion of deficient herds belonged to "sick" group of herds. This conclusion was supported by the mean value of trace elements and by the fact that a majority of individual values of trace elements was below the threshold. Dairy herds had mean values of trace elements higher than beef herds. More concentrates and minerals were used in healthy herds versus "sick" herds. These feed supplements were also used more often in dairy herds, compared to beef herds. Trace elements deficiencies are present in cattle herds in Belgium and are linked to diseases. Nutrition plays a major role in the trace elements status.

Long-term anaerobic digestion of food waste stabilized by trace elements

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

Zhang Lei, E-mail: wxzyfx@yahoo.com; Jahng, Deokjin, E-mail: djahng@mju.ac.kr

Highlights: Black-Right-Pointing-Pointer Korean food waste was found to contain low level of trace elements. Black-Right-Pointing-Pointer Stable anaerobic digestion of food waste was achieved by adding trace elements. Black-Right-Pointing-Pointer Iron played an important role in anaerobic digestion of food waste. Black-Right-Pointing-Pointer Cobalt addition further enhanced the process performance in the presence of iron. - Abstract: The purpose of this study was to examine if long-term anaerobic digestion of food waste in a semi-continuous single-stage reactor could be stabilized by supplementing trace elements. Contrary to the failure of anaerobic digestion of food waste alone, stable anaerobic digestion of food waste was achievedmore » for 368 days by supplementing trace elements. Under the conditions of OLR (organic loading rates) of 2.19-6.64 g VS (volatile solid)/L day and 20-30 days of HRT (hydraulic retention time), a high methane yield (352-450 mL CH{sub 4}/g VS{sub added}) was obtained, and no significant accumulation of volatile fatty acids was observed. The subsequent investigation on effects of individual trace elements (Co, Fe, Mo and Ni) showed that iron was essential for maintaining stable methane production. These results proved that the food waste used in this study was deficient in trace elements.« less

The role of sample preparation in interpretation of trace element concentration variability in moss bioindication studies

USGS Publications Warehouse

Migaszewski, Z.M.; Lamothe, P.J.; Crock, J.G.; Galuszka, A.; Dolegowska, S.

2011-01-01

Trace element concentrations in plant bioindicators are often determined to assess the quality of the environment. Instrumental methods used for trace element determination require digestion of samples. There are different methods of sample preparation for trace element analysis, and the selection of the best method should be fitted for the purpose of a study. Our hypothesis is that the method of sample preparation is important for interpretation of the results. Here we compare the results of 36 element determinations performed by ICP-MS on ashed and on acid-digested (HNO3, H2O2) samples of two moss species (Hylocomium splendens and Pleurozium schreberi) collected in Alaska and in south-central Poland. We found that dry ashing of the moss samples prior to analysis resulted in considerably lower detection limits of all the elements examined. We also show that this sample preparation technique facilitated the determination of interregional and interspecies differences in the chemistry of trace elements. Compared to the Polish mosses, the Alaskan mosses displayed more positive correlations of the major rock-forming elements with ash content, reflecting those elements' geogenic origin. Of the two moss species, P. schreberi from both Alaska and Poland was also highlighted by a larger number of positive element pair correlations. The cluster analysis suggests that the more uniform element distribution pattern of the Polish mosses primarily reflects regional air pollution sources. Our study has shown that the method of sample preparation is an important factor in statistical interpretation of the results of trace element determinations. ?? 2010 Springer-Verlag.

Using column experiments to examine transport of As and other trace elements released from poultry litter: Implications for trace element mobility in agricultural watersheds.

PubMed

Oyewumi, Oluyinka; Schreiber, Madeline E

2017-08-01

Trace elements are added to poultry feed to control infection and improve weight gain. However, the fate of these trace elements in poultry litter is poorly understood. Because poultry litter is applied as fertilizer in many agricultural regions, evaluation of the environmental processes that influence the mobility of litter-derived trace elements is critical for predicting if trace elements are retained in soil or released to water. This study examined the effect of dissolved organic carbon (DOC) in poultry litter leachate on the fate and transport of litter-derived elements (As, Cu, P and Zn) using laboratory column experiments with soil collected from the Delmarva Peninsula (Mid-Atlantic, USA), a region of intense poultry production. Results of the experiments showed that DOC enhanced the mobility of all of the studied elements. However, despite the increased mobility, 60-70% of Zn, As and P mass was retained within the soil. In contrast, almost all of the Cu was mobilized in the litter leachate experiments, with very little retention in soil. Overall, our results demonstrate that the mobility of As, Cu, Zn and P in soils which receive poultry litter application is strongly influenced by both litter leachate composition, specifically organic acids, and adsorption to soil. Results have implications for understanding fate and transport of trace elements released from litter application to soil water and groundwater, which can affect both human health and the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Beneficial Effects of Ants and Spiders on the Reproductive Value of Eriotheca gracilipes (Malvaceae) in a Tropical Savanna

PubMed Central

2015-01-01

Predators affect plant fitness when they forage on them and reduce the action of herbivores. Our study evaluates the complementary effects of spiders and ants that visit the extrafloral nectaries of Eriotheca gracilipes (Malvaceae) on the production of fruits and viable seeds of these savanna trees. Four experimental groups were established: control group – with free access of spiders and ants; exclusion group – spiders and ants excluded; ant group – absence of spiders; and spider group – absence of ants. The presence of ants reduced the spider richness; however, the presence of spiders did not affect the ant richness. A significantly higher number of fruits per buds were found in the presence of spiders alone or spiders and ants together (control group) compared with the absence of both predators (exclusion group). The number of seeds per fruits and seed viability were higher in the control group. This is the first study showing that spiders and ants may exert a positive and complementary effect on the reproductive value of an extrafloral nectaried plant. Mostly the impact of ants and/or spiders on herbivores is considered, whereas our study reinforces the importance of evaluating the effect of multiple predators simultaneously, exploring how the interactions among predators with distinct skills may affect the herbivores and the plants on which they forage. PMID:26168036

Beneficial Effects of Ants and Spiders on the Reproductive Value of Eriotheca gracilipes (Malvaceae) in a Tropical Savanna.

PubMed

Stefani, Vanessa; Pires, Tayna Lopes; Torezan-Silingardi, Helena Maura; Del-Claro, Kleber

2015-01-01

Predators affect plant fitness when they forage on them and reduce the action of herbivores. Our study evaluates the complementary effects of spiders and ants that visit the extrafloral nectaries of Eriotheca gracilipes (Malvaceae) on the production of fruits and viable seeds of these savanna trees. Four experimental groups were established: control group - with free access of spiders and ants; exclusion group - spiders and ants excluded; ant group - absence of spiders; and spider group - absence of ants. The presence of ants reduced the spider richness; however, the presence of spiders did not affect the ant richness. A significantly higher number of fruits per buds were found in the presence of spiders alone or spiders and ants together (control group) compared with the absence of both predators (exclusion group). The number of seeds per fruits and seed viability were higher in the control group. This is the first study showing that spiders and ants may exert a positive and complementary effect on the reproductive value of an extrafloral nectaried plant. Mostly the impact of ants and/or spiders on herbivores is considered, whereas our study reinforces the importance of evaluating the effect of multiple predators simultaneously, exploring how the interactions among predators with distinct skills may affect the herbivores and the plants on which they forage.

Task-irrelevant spider associations affect categorization performance.

PubMed

Woud, Marcella L; Ellwart, Thomas; Langner, Oliver; Rinck, Mike; Becker, Eni S

2011-09-01

In two studies, the Single Target Implicit Association Test (STIAT) was used to investigate automatic associations toward spiders. In both experiments, we measured the strength of associations between pictures of spiders and either threat-related words or pleasant words. Unlike previous studies, we administered a STIAT version in which stimulus contents was task-irrelevant: The target spider pictures were categorized according to the label picture, irrespective of what they showed. In Study 1, spider-fearful individuals versus non-fearful controls were tested, Study 2 compared spider enthusiasts to non-fearful controls. Results revealed that the novel STIAT version was sensitive to group differences in automatic associations toward spiders. In Study 1, it successfully distinguished between spider-fearful individuals and non-fearful controls. Moreover, STIAT scores predicted automatic fear responses best, whereas controlled avoidance behavior was best predicted by the FAS (German translation of the Fear of Spiders Questionnaire). The results of Study 2 demonstrated that the novel STIAT version was also able to differentiate between spider enthusiasts and non-fearful controls. Copyright © 2010 Elsevier Ltd. All rights reserved.

(im)Balance of Forces in the Corona

NASA Astrophysics Data System (ADS)

Sylwester, J.; Sylwester, B.

Observed pattern of variability of solar atmosphere plasma structures, often accompanied by respective measured Doppler shifts, provides a direct evidence of imbalanced forces acting in this environment. Observed motions have been studied in various energy bands, extending from radio to hard X-rays using ground and space-borne instruments. Here, we present the results of a dedicated study of present observational databases in selected energy ranges with a special interest focused on TRACE movies. In our search we included also recently released wavelet-processed EIT and LASCO movies (from SOHO) as they provide additional support to the conclusions of this study. The main outcome of the work performed is our better understanding of a basic role played by plasma kernels in every ``layer'' of the solar atmosphere. These kernels appear to be present, and rapidly evolve at the locations of violent (intense) energy release locations. Subsequent formation of a more stable coronal magnetic structures seen in the form of ``spiders'' or ``scorpions'' is due to self-reorganization of plasma kernels. It comes out that the spider structure represents a basic, quasi-equilibrium building block of the solar atmosphere. When observed in a particular image, within a limited energy band, i.e. optical, EUV, soft or hard X-rays, only a part of this spider plasma structure can usually be seen, noticeably resembling a loop-like structure with a brighter top, or an arcade of loops connected along the ridge of summit kernels, or seemingly isolated oval source. This energy-dependent visibility effects caused a general confusion present in solar physics and led to proliferation of simple fluxtube scenarios. In our study presented herewith, we used the images obtained with the best available resolution, being enhanced numerically where possible. For the first time we enhanced the TRACE image data cube in a systematic way for a particular flare. Based on the results of analysis of a large number of images, we push forward a qualitative toy model of atmospheric connectivity pattern (Sylwester, J. and Sylwester, B., 2004). This hierarchic model is able to handle in a natural way observed complexity of atmospheric phenomena. Here, we discuss to some extent verifiable predictions of the hierarchical model outlining a number of new studies which might prove the concept. These predictions arise concurrently with the first data coming down from new missions being recently launched into orbit: the Hinode and the Stereo.

HUMAN SCALP HAIR: AN ENVIRONMENTAL EXPOSURE INDEX FOR TRACE ELEMENTS. III. SEVENTEEN TRACE ELEMENTS IN BIRMINGHAM, ALABAMA AND CHARLOTTE, NORTH CAROLINA (1972)

EPA Science Inventory

Seventeen trace elements - arsenic (As), barium (Ba), boron, (B), cadmium, (Cd), chromium (Cr), copper (Cu), Iron (Fe), lead (Pb), lithium (Li), manganese (Mn), mercury (Hg), nickel (Ni), selenium (Se), silver (Ag), tin (Sn), vanadium (V), and Zinc (Zn) - were measured in human s...

Trace elements in major marketed marine bivalves from six northern coastal cities of China: concentrations and risk assessment for human health.

PubMed

Li, Peimiao; Gao, Xuelu

2014-11-01

One hundred and fifty nine samples of nine edible bivalve species (Argopecten irradians, Chlamys farreri, Crassostrea virginica, Lasaea nipponica, Meretrix meretrix, Mytilus edulis, Ruditapes philippinarum, Scapharca subcrenata and Sinonovacula constricta) were randomly collected from eight local seafood markets in six big cities (Dalian, Qingdao, Rizhao, Weifang, Weihai and Yantai) in the northern coastal areas of China for the investigation of trace element contamination. As, Cd, Cr, Cu, Hg, Pb and Zn were quantified. The risk of these trace elements to humans through bivalve consumption was then assessed. Results indicated that the concentrations of most of the studied trace element varied significantly with species: the average concentration of Cu in C. virginica was an order of magnitude higher than that in the remaining species; the average concentration of Zn was also highest in C. virginica; the average concentration of As, Cd and Pb was highest in R. philippinarum, C. farreri and A. irradians, respectively. Spatial differences in the concentrations of elements were generally less than those of interspecies, yet some elements such as Cr and Hg in the samples from different cities showed a significant difference in concentrations for some bivalve species. Trace element concentrations in edible tissues followed the order of Zn>Cu>As>Cd>Cr>Pb>Hg generally. Statistical analysis (one-way ANOVA) indicated that different species examined showed different bioaccumulation of trace elements. There were significant correlations between the concentrations of some elements. The calculated hazard quotients indicated in general that there was no obvious health risk from the intake of trace elements through bivalve consumption. But care must be taken considering the increasing amount of seafood consumption. Copyright © 2014 Elsevier Inc. All rights reserved.

The occurrence and distribution of selected trace elements in the upper Rio Grande and tributaries in Colorado and Northern New Mexico

USGS Publications Warehouse

Taylor, Howard E.; Antweiler, Ronald C.; Roth, D.A.; Brinton, T.I.; Peart, D.B.; Healy, D.F.

2001-01-01

Two sampling trips were undertaken in 1994 to determine the distribution of trace elements in the Upper Rio Grande and several of its tributaries. Water discharges decreased in the main stem of the Rio Grande from June to September, whereas dissolved concentrations of trace elements generally increased. This is attributed to dilution of base flow from snowmelt runoff in the June samples. Of the three major mining districts (Creede, Summitville, and Red River) in the Upper Rio Grande drainage basin, only the Creede District appears to impact the Rio Grande in a significant manner, with both waters and sediments having elevated concentrations of some trace elements considerably downriver. For example, dissolved zinc concentrations upriver of Willow Creek, which primarily drains the Creede District, were about 2-3 μg/L; immediately downstream of the Willow Creek confluence, concentrations were above 20 μg/L; and elevated concentrations occurred in the Rio Grande for the next 100 km. The Red River District does not significantly impact the Upper Rio Grande for most trace elements. Because of current water management practices, it is difficult to assess the impact of the Summitville District on the Upper Rio Grande. There are, however, large increases in many dissolved trace element concentrations as the Rio Grande passes through the San Luis Valley, coincident with elevated concentrations of those same trace elements in tributaries. Among these elements are As, B, Cr, Li, Mn, Mo, Ni, Sr, U, and V. None of the trace elements exceeded U.S. EPA primary drinking water standards in either survey, with the exception of cadmium in Willow Creek. Secondary drinking water standards were frequently violated, especially in tributaries draining areas where mining has occurred. Dissolved zinc (in Willow Creek in both June and September) was the only element that exceeded the EPA Water Quality Criteria for aquatic life of 120 μg/L.

An estimated 400-800 million tons of prey are annually killed by the global spider community.

PubMed

Nyffeler, Martin; Birkhofer, Klaus

2017-04-01

Spiders have been suspected to be one of the most important groups of natural enemies of insects worldwide. To document the impact of the global spider community as insect predators, we present estimates of the biomass of annually killed insect prey. Our estimates assessed with two different methods suggest that the annual prey kill of the global spider community is in the range of 400-800 million metric tons (fresh weight), with insects and collembolans composing >90% of the captured prey. This equals approximately 1‰ of the global terrestrial net primary production. Spiders associated with forests and grasslands account for >95% of the annual prey kill of the global spider community, whereas spiders in other habitats are rather insignificant contributors over a full year. The spider communities associated with annual crops contribute less than 2% to the global annual prey kill. This, however, can be partly explained by the fact that annual crop fields are "disturbed habitats" with a low buildup of spider biomass and that agrobiont spiders often only kill prey over short time periods in a year. Our estimates are supported by the published results of exclusion experiments, showing that the number of herbivorous/detritivorous insects and collembolans increased significantly after spider removal from experimental plots. The presented estimates of the global annual prey kill and the relative contribution of spider predation in different biomes improve the general understanding of spider ecology and provide a first assessment of the global impact of this very important predator group.

An estimated 400-800 million tons of prey are annually killed by the global spider community

NASA Astrophysics Data System (ADS)

Nyffeler, Martin; Birkhofer, Klaus

2017-04-01

Spiders have been suspected to be one of the most important groups of natural enemies of insects worldwide. To document the impact of the global spider community as insect predators, we present estimates of the biomass of annually killed insect prey. Our estimates assessed with two different methods suggest that the annual prey kill of the global spider community is in the range of 400-800 million metric tons (fresh weight), with insects and collembolans composing >90% of the captured prey. This equals approximately 1‰ of the global terrestrial net primary production. Spiders associated with forests and grasslands account for >95% of the annual prey kill of the global spider community, whereas spiders in other habitats are rather insignificant contributors over a full year. The spider communities associated with annual crops contribute less than 2% to the global annual prey kill. This, however, can be partly explained by the fact that annual crop fields are "disturbed habitats" with a low buildup of spider biomass and that agrobiont spiders often only kill prey over short time periods in a year. Our estimates are supported by the published results of exclusion experiments, showing that the number of herbivorous/detritivorous insects and collembolans increased significantly after spider removal from experimental plots. The presented estimates of the global annual prey kill and the relative contribution of spider predation in different biomes improve the general understanding of spider ecology and provide a first assessment of the global impact of this very important predator group.

Time till death affects spider mobility and web-building behavior during web construction in an orb-web spider.

PubMed

Anotaux, Mylène; Toscani, Camille; Leborgne, Raymond; Chaline, Nicolas; Pasquet, Alain

2016-04-01

It is well known that age influences organism mobility. This was demonstrated in vertebrates (such as mammals and birds) but has been less studied in invertebrates with the exception of Drosophila and the nematode Caenorhabditis elegans. Here we studied the influence of age on the mobility of the orb-weaving spider Zygiella x-notata during web construction. The orb-web is a good model because it has a characteristic geometrical structure and video tracking can be used to easily follow the spider's movements during web building. We investigated the influence of age (specifically chronological age, life span, and time till death) on different parameters of spider mobility during the construction of the capture spiral (distance traveled, duration of construction, spider velocity, spider movement, and spider inactivity) with a generalized linear model (GLM) procedure adjusted for the spider mass. The results showed that neither chronological age, nor life span affected the mobility parameters. However, when the time till death decreased, there was a decrease in the distance traveled, the duration of the construction of the capture spiral, and the spider movement. The spider velocity and the time of inactivity were not affected. These results could be correlated with a decrease in the length of the silky thread deposited for the construction of the capture spiral. Spiders with a shorter time till death built smaller web using less silk. Thus, our study suggests strongly that time till death affects spider mobility during web construction but not the chronological age and thus may be a good indicator of senescence.

Trace elements contamination and human health risk assessment in drinking water from Shenzhen, China.

PubMed

Lu, Shao-You; Zhang, Hui-Min; Sojinu, Samuel O; Liu, Gui-Hua; Zhang, Jian-Qing; Ni, Hong-Gang

2015-01-01

The levels of seven essential trace elements (Mn, Co, Ni, Cu, Zn, Se, and Mo) and six non-essential trace elements (Cr, As, Cd, Sb, Hg, and Pb) in a total of 89 drinking water samples collected in Shenzhen, China were determined using inductively coupled plasma mass spectrometry (ICP-MS) in the present study. Both the essential and non-essential trace elements were frequently detectable in the different kinds of drinking waters assessed. Remarkable temporal and spatial variations were observed among most of the trace elements in the tap water collected from two tap water treatment plants. Meanwhile, potential human health risk from these non-essential trace elements in the drinking water for local residents was also assessed. The median values of cancer risks associated with exposure to carcinogenic metals via drinking water consumption were estimated to be 6.1 × 10(-7), 2.1 × 10(-8), and 2.5 × 10(-7) for As, Cd, and Cr, respectively; the median values of incremental lifetime for non-cancer risks were estimated to be 6.1 × 10(-6), 4.4 × 10(-5), and 2.2 × 10(-5) for Hg, Pb, and Sb, respectively. The median value of total incremental lifetime health risk induced by the six non-essential trace elements for the population was 3.5 × 10(-5), indicating that the potential health risks from non-carcinogenic trace elements in drinking water also require some attention. Sensitivity analysis indicates that the most important factor for health risk assessment should be the levels of heavy metal in drinking water.

First report of clinical presentation of a bite by a running spider, Philodromus sp. (Araneae: Philodromidae), with recommendations for spider bite management.

PubMed

Coetzee, Maureen; Dippenaar, Ansie; Frean, John; Hunt, Richard H

2017-06-30

This article describes the clinical progression of symptoms over a period of 5 days of a bite inflicted by a Philodromus sp. spider. Commonly known as 'running spiders', these are not considered to be harmful to humans. This report, however, is the first description of an actual bite by a member of this group of spiders showing cytotoxic envenomation. Management of the bites should be as recommended for other cytotoxic spider bites.

Solubilization of spider silk proteins and its structural analysis using Fourier transform infrared spectroscopy

NASA Astrophysics Data System (ADS)

Osbin, K.; Jayan, Manuel; Bhadrakumari, S.; Predeep, P.

2017-06-01

This study investigates the presence of various amide bands present in different spider silk species, which provides extraordinary physical properties. Three different spider silks were collected from Western Ghats region. The collected spider silks samples belonging to the spider Heteropoda venatoria (species 1), Hersilia savignyi (species 2) and Pholcus phalangioides (species 3). Fourier transform infrared (FTIR) spectra reveals the protein peaks in the amide I, II, and III regions in all the three types of spider silk species.

Distribution of trace elements in the coastal sea sediments of Maslinica Bay, Croatia

NASA Astrophysics Data System (ADS)

Mikulic, Nenad; Orescanin, Visnja; Elez, Loris; Pavicic, Ljiljana; Pezelj, Durdica; Lovrencic, Ivanka; Lulic, Stipe

2008-02-01

Spatial distributions of trace elements in the coastal sea sediments and water of Maslinica Bay (Southern Adriatic), Croatia and possible changes in marine flora and foraminifera communities due to pollution were investigated. Macro, micro and trace elements’ distributions in five granulometric fractions were determined for each sediment sample. Bulk sediment samples were also subjected to leaching tests. Elemental concentrations in sediments, sediment extracts and seawater were measured by source excited energy dispersive X-ray fluorescence (EDXRF). Concentrations of the elements Cr, Cu, Zn, and Pb in bulk sediment samples taken in the Maslinica Bay were from 2.1 to over six times enriched when compared with the background level determined for coarse grained carbonate sediments. A low degree of trace elements leaching determined for bulk sediments pointed to strong bonding of trace elements to sediment mineral phases. The analyses of marine flora pointed to higher eutrophication, which disturbs the balance between communities and natural habitats.

Long-term anaerobic digestion of food waste stabilized by trace elements.

PubMed

Zhang, Lei; Jahng, Deokjin

2012-08-01

The purpose of this study was to examine if long-term anaerobic digestion of food waste in a semi-continuous single-stage reactor could be stabilized by supplementing trace elements. Contrary to the failure of anaerobic digestion of food waste alone, stable anaerobic digestion of food waste was achieved for 368 days by supplementing trace elements. Under the conditions of OLR (organic loading rates) of 2.19-6.64 g VS (volatile solid)/L day and 20-30 days of HRT (hydraulic retention time), a high methane yield (352-450 mL CH(4)/g VS(added)) was obtained, and no significant accumulation of volatile fatty acids was observed. The subsequent investigation on effects of individual trace elements (Co, Fe, Mo and Ni) showed that iron was essential for maintaining stable methane production. These results proved that the food waste used in this study was deficient in trace elements. Copyright © 2012. Published by Elsevier Ltd.

Concentrations of mercury and other trace elements in walleye, smallmouth bass, and rainbow trout in Franklin D. Roosevelt Lake and the upper Columbia River, Washington, 1994

USGS Publications Warehouse

Munn, M.D.; Cox, S.E.; Dean, C.J.

1995-01-01

Three species of sportfish--walleye, smallmouth bass, and rainbow trout--were collected from Franklin D. Roosevelt Lake and the upstream reach of the Columbia River within the state of Washington, to determine the concentrations of mercury and other selected trace elements in fish tissue. Concentrations of total mercury in walleye fillets ranged from 0.11 to 0.44 milligram per kilogram, with the higher concentrations in the larger fish. Fillets of smallmouth bass and rainbow trout also contained mercury, but generally at lower concentrations. Other selected trace elements were found in fillet samples, but the concentrations were generally low depending on species and the specific trace element. The trace elements cadmium, copper, lead, and zinc were found in liver tissue of these same species with zinc consistently present in the highest concentration.

Arbuscular mycorrhizal fungi in phytoremediation of contaminated areas by trace elements: mechanisms and major benefits of their applications.

PubMed

Cabral, Lucélia; Soares, Claúdio Roberto Fonsêca Sousa; Giachini, Admir José; Siqueira, José Oswaldo

2015-11-01

In recent decades, the concentration of trace elements has increased in soil and water, mainly by industrialization and urbanization. Recovery of contaminated areas is generally complex. In that respect, microorganisms can be of vital importance by making significant contributions towards the establishment of plants and the stabilization of impacted areas. Among the available strategies for environmental recovery, bioremediation and phytoremediation outstand. Arbuscular mycorrhizal fungi (AMF) are considered the most important type of mycorrhizae for phytoremediation. AMF have broad occurrence in contaminated soils, and evidences suggest they improve plant tolerance to excess of certain trace elements. In this review, the use of AMF in phytoremediation and mechanisms involved in their trace element tolerance are discussed. Additionally, we present some techniques used to study the retention of trace elements by AMF, as well as a summary of studies showing major benefits of AMF for phytoremediation.

Benthic foraminifera as bio-indicators of trace element pollution in the heavily contaminated Santa Gilla lagoon (Cagliari, Italy).

PubMed

Frontalini, Fabrizio; Buosi, Carla; Da Pelo, Stefania; Coccioni, Rodolfo; Cherchi, Antonietta; Bucci, Carla

2009-06-01

In order to assess the response of benthic foraminifera to trace element pollution, a study of benthic foraminiferal assemblages was carried out into sediment samples collected from the Santa Gilla lagoon (Sardinia, Italy). The lagoon has been contaminated by industrial waste, mainly trace elements, as well as by agricultural and domestic effluent. The analysis of surficial sediment shows enrichment in trace elements, including Cr, Cu, Hg, Ni, Pb and Zn. Biotic and abiotic data, analyzed with multivariate techniques of statistical analysis, reveal a distinct separation of both the highly polluted and less polluted sampling sites. The innermost part of the lagoon, comprising the industrial complex at Macchiareddu, is exposed to a high load of trace elements which are probably enhanced by their accumulation in the finer sediment fraction. This area reveals lower diversity and higher percentages of abnormalities when compared to the outermost part of the lagoon.

Funnel-web spider bite

MedlinePlus

... page: //medlineplus.gov/ency/article/002844.htm Funnel-web spider bite To use the sharing features on ... the effects of a bite from the funnel-web spider. Male funnel-web spiders are more poisonous ...

Modeling and design of a beam emission spectroscopy diagnostic for the negative ion source NIO1

NASA Astrophysics Data System (ADS)

Barbisan, M.; Zaniol, B.; Cavenago, M.; Pasqualotto, R.

2014-02-01

Consorzio RFX and INFN-LNL are building a flexible small ion source (Negative Ion Optimization 1, NIO1) capable of producing about 130 mA of H- ions accelerated at 60 KeV. Aim of the experiment is to test and develop the instrumentation for SPIDER and MITICA, the prototypes, respectively, of the negative ion sources and of the whole neutral beam injectors which will operate in the ITER experiment. As SPIDER and MITICA, NIO1 will be monitored with beam emission spectroscopy (BES), a non-invasive diagnostic based on the analysis of the spectrum of the Hα emission produced by the interaction of the energetic ions with the background gas. Aim of BES is to monitor direction, divergence, and uniformity of the ion beam. The precision of these measurements depends on a number of factors related to the physics of production and acceleration of the negative ions, to the geometry of the beam, and to the collection optics. These elements were considered in a set of codes developed to identify the configuration of the diagnostic which minimizes the measurement errors. The model was already used to design the BES diagnostic for SPIDER and MITICA. The paper presents the model and describes its application to design the BES diagnostic in NIO1.

Temperature and Gravity Dependence of Trace Element Abundances in Hot DA White Dwarfs (94-EUVE-094)

NASA Technical Reports Server (NTRS)

Finley, David S.

1998-01-01

EUV spectroscopy has shown that DA white dwarfs hotter than about 45,000 K may contain trace heavy elements, while those hotter than about 50,000 K almost always have significant abundances of trace heavy elements. One of our continuing challenges is to identify and determine the abundances of these trace constituents, and then to relate the observed abundance patterns to the present conditions and previous evolutionary histories of the hot DA white dwarfs.

Trace elements in urban and suburban rainfall, Mersin, Northeastern Mediterranean

NASA Astrophysics Data System (ADS)

Özsoy, Türkan; Örnektekin, Sermin

2009-10-01

Spatial/temporal variabilities of rainwater constituents are examined based on soluble/insoluble trace elements, pH and electrical conductivity measurements in rainfall sampled during December 2003-May 2005 at two urban and two suburban sites in Mersin, an industrialized city of 850,000 inhabitants on the southern coast of Turkey. In the analyses, backward air mass trajectories for rainy days were used in addition to factor analyses, enrichment factors, phase distributions and correlations between trace elements. The pH varied from 4.8 to 8.5 with an average value of 6.2, reflecting a mainly alkaline regime. Mean concentrations of trace elements collected from urban and suburban sites are spatially variable. Based on the overall data, total concentrations of trace elements were ordered as Ca > Na > Fe > Al > Mg > K > Zn > Mn > Sr > Pb > Ni > Cr > Ba > Cu > Co > Cd. Mainly terrigeneous (Ca, Fe, Al) and, to a lesser extent, sea salt particles (Na, Mg) were shown to be the major source of trace elements. Excluding major cations, the solubilities of trace elements were found to be ordered as Sr > Zn > Ba > Mn > Cu > Ni > Cr > Fe > Al, confirming the lower solubility of crustal elements. Cd, Co and Pb were excluded from the above evaluation because of the low numbers of soluble samples allowing quantitative measurements. The solubilities of Al, Fe, Mn and particularly of Ni were found to be considerably lower than those reported for various sites around the world, most likely due to the effect of pH. During the entire sampling period, a total of 28 dust transport episodes associated with 31 red rain events were identified. Extremely high mean concentration ratios of Al (8.2), Fe (14.4) and Mn (13.1) were observed in red rain, compared to normal rain. The degree of this enhancement displayed a decrease from crustal to anthropogenic origin elements and the lowest enhancements were found for anthropogenic origin elements of Zn and Cd (both having a ratio of 1.1). Aerosol dust was found to be the main source of almost all analyzed elements in Mersin precipitation, regardless that they are crustal or anthropic derived elements. The magnitude of crustal source contribution to trace element budget of precipitation was at its highest levels for crustal originated elements, most probably due to much higher scavenging ratios of crustal elements compared to anthropogenic ones.

Respiration in spiders (Araneae).

PubMed

Schmitz, Anke

2016-05-01

Spiders (Araneae) are unique regarding their respiratory system: they are the only animal group that breathe simultaneously with lungs and tracheae. Looking at the physiology of respiration the existence of tracheae plays an important role in spiders with a well-developed tracheal system. Other factors as sex, life time, type of prey capture and the high ability to gain energy anaerobically influence the resting and the active metabolic rate intensely. Most spiders have metabolic rates that are much lower than expected from body mass; but especially those with two pairs of lungs. Males normally have higher resting rates than females; spiders that are less evolved and possess a cribellum have lower metabolic rates than higher evolved species. Freely hunting spiders show a higher energy turnover than spiders hunting with a web. Spiders that live longer than 1 year will have lower metabolic rates than those species that die after 1 year in which development and reproduction must be completed. Lower temperatures and starvation, which most spiders can cope with, will decrease the metabolic rate as well.

Trace elements in animal-based food from Shanghai markets and associated human daily intake and uptake estimation considering bioaccessibility.

PubMed

Lei, Bingli; Chen, Liang; Hao, Ying; Cao, Tiehua; Zhang, Xinyu; Yu, Yingxin; Fu, Jiamo

2013-10-01

The concentrations of four human essential trace elements [iron (Fe), manganese (Mn), zinc (Zn), chromium (Cr)] and non-essential elements [cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg)] in eighteen animal-based foods including meat, fish, and shellfish collected from markets in Shanghai, China, were analyzed, and the associated human daily intake and uptake considering bioaccessibility were estimated. The mean concentration ranges for eight trace elements measured in the foods were 3.98-131µgg(-1) for Fe, 0.437-18.5µgg(-1) for Mn, 5.47-53.8µgg(-1) for Zn, none detected-0.101µgg(-1) for Cr, 2.88×10(-4)-2.48×10(-2)µgg(-1) for Cd, 1.18×10(-3)-0.747µgg(-1) for Pb, none detected-0.498µgg(-1) for As, and 8.98×10(-4)-6.52×10(-2)µgg(-1) for Hg. The highest mean concentrations of four human essential elements were all found in shellfish. For all the trace elements, the observed mean concentrations are mostly in agreement with the reported values around the world. The total daily intake of trace elements via ingestion of animal-based food via an average Shanghai resident was estimated as 7371µgd(-1) for the human essential elements and 13.0µgd(-1) for the human non-essential elements, but the uptake decreased to 4826µgd(-1) and 6.90µgd(-1), respectively, after trace element bioaccessibility was considered. Livestock and fish for human essential and non-essential elements, respectively, were the main contributor, no matter whether the bioaccessibility was considered or not. Risk estimations showed that the intake and uptake of a signal trace element for an average Shanghai resident via ingestion animal-based foods from Shanghai markets do not exceed the recommended dietary allowance values; consequently, a health risk situation is not indicated. Copyright © 2013. Published by Elsevier Inc.

Spider Bites (For Parents)

MedlinePlus

... Videos for Educators Search English Español First Aid: Spider Bites KidsHealth / For Parents / First Aid: Spider Bites ... rare. Signs and Symptoms Of a brown recluse spider bite: red blister in the center with surrounding ...

Synthetic Engineering of Spider Silk Fiber as Implantable Optical Waveguides for Low-Loss Light Guiding.

PubMed

Qiao, Xin; Qian, Zhigang; Li, Junjie; Sun, Hongji; Han, Yao; Xia, Xiaoxia; Zhou, Jin; Wang, Chunlan; Wang, Yan; Wang, Changyong

2017-05-03

A variety of devices used for biomedical engineering have been fabricated using protein polymer because of their excellent properties, such as strength, toughness, biocompatibility, and biodegradability. In this study, we fabricated an optical waveguide using genetically engineered spider silk protein. This method has two significant advantages: (1) recombinant spider silk optical waveguide exhibits excellent optical and biological properties and (2) biosynthesis of spider silk protein can overcome the limitation to the research on spider silk optical waveguide due to the low yield of natural spider silk. In detail, two kinds of protein-based optical waveguides made from recombinant spider silk protein and regenerative silkworm silk protein were successfully prepared. Results suggested that the recombinant spider silk optical waveguide showed a smoother surface and a higher refractive index when compared with regenerative silkworm silk protein. The optical loss of recombinant spider silk optical waveguide was 0.8 ± 0.1 dB/cm in air and 1.9 ± 0.3 dB/cm in mouse muscles, which were significantly lower than those of regenerative silkworm silk optical waveguide. Moreover, recombinant spider silk optical waveguide can meet the demand to guide and efficiently deliver light through biological tissue. In addition, recombinant spider silk optical waveguide showed low toxicity to cells in vitro and low-level inflammatory reaction with surrounding tissue in vivo. Therefore, recombinant spider silk optical waveguide is a promising implantable device to guide and deliver light with low loss.

Trace elements and radionuclides in palm oil, soil, water, and leaves from oil palm plantations: A review.

PubMed

Olafisoye, O B; Oguntibeju, O O; Osibote, O A

2017-05-03

Oil palm (Elaeisguineensis) is one of the most productive oil producing plant in the world. Crude palm oil is composed of triglycerides supplying the world's need of edible oils and fats. Palm oil also provides essential elements and antioxidants that are potential mediators of cellular functions. Experimental studies have demonstrated the toxicity of the accumulation of significant amounts of nonessential trace elements and radionuclides in palm oil that affects the health of consumers. It has been reported that uptake of trace elements and radionuclides from the oil palm tree may be from water and soil on the palm plantations. In the present review, an attempt was made to revise and access knowledge on the presence of some selected trace elements and radionuclides in palm oil, soil, water, and leaves from oil palm plantations based on the available facts and data. Existing reports show that the presence of nonessential trace elements and radionuclides in palm oil may be from natural or anthropogenic sources in the environment. However, the available literature is limited and further research need to be channeled to the investigation of trace elements and radionuclides in soil, water, leaves, and palm oil from oil palm plantations around the globe.

Nutritional Aspects of Essential Trace Elements in Oral Health and Disease: An Extensive Review

PubMed Central

Hussain, Mohsina

2016-01-01

Human body requires certain essential elements in small quantities and their absence or excess may result in severe malfunctioning of the body and even death in extreme cases because these essential trace elements directly influence the metabolic and physiologic processes of the organism. Rapid urbanization and economic development have resulted in drastic changes in diets with developing preference towards refined diet and nutritionally deprived junk food. Poor nutrition can lead to reduced immunity, augmented vulnerability to various oral and systemic diseases, impaired physical and mental growth, and reduced efficiency. Diet and nutrition affect oral health in a variety of ways with influence on craniofacial development and growth and maintenance of dental and oral soft tissues. Oral potentially malignant disorders (OPMD) are treated with antioxidants containing essential trace elements like selenium but even increased dietary intake of trace elements like copper could lead to oral submucous fibrosis. The deficiency or excess of other trace elements like iodine, iron, zinc, and so forth has a profound effect on the body and such conditions are often diagnosed through their early oral manifestations. This review appraises the biological functions of significant trace elements and their role in preservation of oral health and progression of various oral diseases. PMID:27433374

In-drop capillary spooling of spider capture thread inspires hybrid fibers with mixed solid–liquid mechanical properties

PubMed Central

Elettro, Hervé; Neukirch, Sébastien; Vollrath, Fritz; Antkowiak, Arnaud

2016-01-01

An essential element in the web-trap architecture, the capture silk spun by ecribellate orb spiders consists of glue droplets sitting astride a silk filament. Mechanically this thread presents a mixed solid–liquid behavior unknown to date. Under extension, capture silk behaves as a particularly stretchy solid, owing to its molecular nanosprings, but it totally switches behavior in compression to now become liquid-like: It shrinks with no apparent limit while exerting a constant tension. Here, we unravel the physics underpinning the unique behavior of this ”liquid wire” and demonstrate that its mechanical response originates in the shape-switching of the silk filament induced by buckling within the droplets. Learning from this natural example of geometry and mechanics, we manufactured programmable liquid wires that present previously unidentified pathways for the design of new hybrid solid–liquid materials. PMID:27185930

In-drop capillary spooling of spider capture thread inspires hybrid fibers with mixed solid-liquid mechanical properties.

PubMed

Elettro, Hervé; Neukirch, Sébastien; Vollrath, Fritz; Antkowiak, Arnaud

2016-05-31

An essential element in the web-trap architecture, the capture silk spun by ecribellate orb spiders consists of glue droplets sitting astride a silk filament. Mechanically this thread presents a mixed solid-liquid behavior unknown to date. Under extension, capture silk behaves as a particularly stretchy solid, owing to its molecular nanosprings, but it totally switches behavior in compression to now become liquid-like: It shrinks with no apparent limit while exerting a constant tension. Here, we unravel the physics underpinning the unique behavior of this "liquid wire" and demonstrate that its mechanical response originates in the shape-switching of the silk filament induced by buckling within the droplets. Learning from this natural example of geometry and mechanics, we manufactured programmable liquid wires that present previously unidentified pathways for the design of new hybrid solid-liquid materials.

Effects of contact shape on the scaling of biological attachments

NASA Astrophysics Data System (ADS)

Spolenak, Ralph; Gorb, Stanislav; Gao, Huajian; Arzt, Eduard

2005-02-01

Adhesion of biological systems has recently received much research attention: the survival of organisms ranging from single cells and mussels to insects, spiders and geckos relies crucially on their mechanical interaction with their environments. For spiders, lizards and possible other 'dry' adhesive systems, explanations for adhesion are based on van der Waals interaction, and the adhesion of single-contact elements has been described by the classical Johnson-Kendall-Roberts (JKR) model derived for spherical contacts. However, real biological contacts display a variety of shapes and only rarely resemble a hemisphere. Here, we theoretically assess the influence of various contact shapes on the pull-off force for single contacts as well as their scaling potential in contact arrays. It is concluded that other shapes, such as a toroidal contact geometry, should lead to better attachment; such geometries are observed in our microscopic investigations of hair-tip shapes in beetles and flies.

In-drop capillary spooling of spider capture thread inspires hybrid fibers with mixed solid-liquid mechanical properties

NASA Astrophysics Data System (ADS)

Elettro, Hervé; Neukirch, Sébastien; Vollrath, Fritz; Antkowiak, Arnaud

2016-05-01

An essential element in the web-trap architecture, the capture silk spun by ecribellate orb spiders consists of glue droplets sitting astride a silk filament. Mechanically this thread presents a mixed solid-liquid behavior unknown to date. Under extension, capture silk behaves as a particularly stretchy solid, owing to its molecular nanosprings, but it totally switches behavior in compression to now become liquid-like: It shrinks with no apparent limit while exerting a constant tension. Here, we unravel the physics underpinning the unique behavior of this ”liquid wire” and demonstrate that its mechanical response originates in the shape-switching of the silk filament induced by buckling within the droplets. Learning from this natural example of geometry and mechanics, we manufactured programmable liquid wires that present previously unidentified pathways for the design of new hybrid solid-liquid materials.

Trace element partitioning between ionic crystal and liquid

NASA Technical Reports Server (NTRS)

Tsang, T.; Philpotts, J. A.; Yin, L.

1978-01-01

The partitioning of trace elements between ionic crystals and the melt has been correlated with lattice energy of the host. The solid-liquid partition coefficient has been expressed in terms of the difference in relative ionic radius of the trace element and the homogeneous and heterogeneous strain of the host lattice. Predictions based on this model appear to be in general agreement with data for alkali nitrates and for rare-earth elements in natural garnet phenocrysts.

Phytoaccumulation of trace elements by wetland plants. 2: Water hyacinth

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

Zhu, Y.L.; Zayed, A.M.; Qian, J.H.

Wetland plants are being used successfully for the phytoremediation of trace elements in natural and constructed wetlands. This study demonstrates the potential of water hyacinth (Eichhornia crassipes), an aquatic floating plant, for the phytoremediation of six trace elements. The ability of water hyacinth to take up and translocate six trace elements--As(V), Cd(II), Cr(VI), Cu(II), Ni(II), and Se(VI)--was studied under controlled conditions. Water hyacinth accumulated Cd and Cr best, Se and Cu at moderate levels, and was a poor accumulator of As and Ni. The highest levels of Cd found in shoots and roots were 371 and 6103 mg kg[sup [minus]1]more » dry wt., respectively, and those of Cr were 119 and 32951 mg kg[sup [minus]1] dry wt, respectively. Cadmium, Cr, Cu, Ni, and As were more highly accumulated in roots than in shoots. In contrast, Se was accumulated more in shoots than in roots at most external concentrations. Water hyacinth had high trace element bioconcentration factors when supplied with low external concentrations of all six elements, particularly Cd, Cr, and Cu. Therefore, water hyacinth will be very efficient at phytoextracting trace elements from wastewater containing low concentrations of these elements. The authors conclude that water hyacinth is a promising candidate for phytoremediation of wastewater polluted with Cd, Cr, Cu, and Se.« less

Trace element analysis of soil type collected from the Manjung and central Perak

NASA Astrophysics Data System (ADS)

Azman, Muhammad Azfar; Hamzah, Suhaimi; Rahman, Shamsiah Abdul; Elias, Md Suhaimi; Abdullah, Nazaratul Ashifa; Hashim, Azian; Shukor, Shakirah Abd; Kamaruddin, Ahmad Hasnulhadi Che

2015-04-01

Trace elements in soils primarily originated from their parent materials. Parents' material is the underlying geological material that has been undergone different types of chemical weathering and leaching processes. Soil trace elements concentrations may be increases as a result of continuous input from various human activities, including power generation, agriculture, mining and manufacturing. This paper describes the Neutron Activation Analysis (NAA) method used for the determination of trace elements concentrations in part per million (ppm) present in the terrestrial environment soil in Perak. The data may indicate any contamination of trace elements contributed from human activities in the area. The enrichment factors were used to check if there any contamination due to the human activities (power plants, agricultural, mining, etc.) otherwise the values would serve as a baseline data for future study. The samples were collected from 27 locations of different soil series in the area at two different depths: the top soil (0-15cm) and the sub soil (15-30cm). The collected soil samples were air dried at 60°C and passed through 2 µm sieve. Instrumental Neutron Activation Analysis (NAA) has been used for the determination of trace elements. Samples were activated in the Nuclear Malaysia TRIGA Mark II reactor followed by gamma spectrometric analysis. By activating the stable elements in the samples, the elements can be determined from the intensities of gamma energies emitted by the respected radionuclides.

Seasonal variations of trace elements in precipitation at the largest city in Tibet, Lhasa

NASA Astrophysics Data System (ADS)

Guo, Junming; Kang, Shichang; Huang, Jie; Zhang, Qianggong; Tripathee, Lekhendra; Sillanpää, Mika

2015-02-01

Precipitation samples were collected from March 2010 to August 2012 at an urban site in Lhasa, the capital and largest city of Tibet. The volume weighted mean (VWM) concentrations of 17 trace elements in precipitation were higher during the non-monsoon season than in the monsoon season, but inverse seasonal variations occurred for wet deposition fluxes of most of the trace elements. Concentrations for most of trace elements were negatively correlated with precipitation amount, indicating that below-cloud scavenging of trace elements was an important mechanism contributing to wet deposition of these elements. The elements Al, Sc, V, Cr, Mn, Fe, Mn, Ni, and U displayed low crustal enrichment factors (EFs), whereas Co, Cu, Zn, As, Cd Sn, Pb, and Bi showed high EF values in precipitation, suggesting that anthropogenic activities might be important contributors of these elements at Lhasa. However, this present work indicates a much lower anthropogenic emission at Lhasa than in seriously polluted regions. Our study will not only provide insights for assessing the current status of the atmospheric environment in Lhasa but also enhance our understanding for updating the baseline for environmental protection over the Tibetan Plateau.

The abundance and relative volatility of refractory trace elements in Allende Ca,Al-rich inclusions - Implications for chemical and physical processes in the solar nebula

NASA Technical Reports Server (NTRS)

Kornacki, Alan S.; Fegley, Bruce, Jr.

1986-01-01

The relative volatilities of lithophile refractory trace elements (LRTE) were determined using calculated 50-percent condensation temperatures. Then, the refractory trace-element abundances were measured in about 100 Allende inclusions. The abundance patterns found in Allende Ca,Al-rich inclusions (CAIs) and ultrarefractory inclusions were used to empirically modify the calculated LRTE volatility sequence. In addition, the importance of crystal-chemical effects, diffusion constraints, and grain transport for the origin of the trace-element chemistry of Allende CAIs (which have important implications for chemical and physical processes in the solar nebula) is discussed.

Nanometer-sized materials for solid-phase extraction of trace elements.

PubMed

Hu, Bin; He, Man; Chen, Beibei

2015-04-01

This review presents a comprehensive update on the state-of-the-art of nanometer-sized materials in solid-phase extraction (SPE) of trace elements followed by atomic-spectrometry detection. Zero-dimensional nanomaterials (fullerene), one-dimensional nanomaterials (carbon nanotubes, inorganic nanotubes, and nanowires), two-dimensional nanomaterials (nanofibers), and three-dimensional nanomaterials (nanoparticles, mesoporous nanoparticles, magnetic nanoparticles, and dendrimers) for SPE are discussed, with their application for trace-element analysis and their speciation in different matrices. A variety of other novel SPE sorbents, including restricted-access sorbents, ion-imprinted polymers, and metal-organic frameworks, are also discussed, although their applications in trace-element analysis are relatively scarce so far.

Trace elements geochemistry of fractured basement aquifer in southern Malawi: A case of Blantyre rural

NASA Astrophysics Data System (ADS)

Mapoma, Harold Wilson Tumwitike; Xie, Xianjun; Nyirenda, Mathews Tananga; Zhang, Liping; Kaonga, Chikumbusko Chiziwa; Mbewe, Rex

2017-07-01

In this study, twenty one (21) trace elements in the basement complex groundwater of Blantyre district, Malawi were analyzed. The majority of the analyzed trace elements in the water were within the standards set by World Health Organization (WHO) and Malawi Standards Board (MSB). But, iron (Fe) (BH16 and 21), manganese (Mn) (BH01) and selenium (Se) (BH02, 13, 18, 19 and 20) were higher than the WHO and MSB standards. Factor analysis (FA) revealed up to five significant factors which accounted for 87.4% of the variance. Factor 1, 2 and 3 suggest evaporite dissolution and silicate weathering processes while the fourth factor may explain carbonate dissolution and pH influence on trace element geochemistry of the studied groundwater samples. According to PHREEQC computed saturation indices, dissolution, precipitation and rock-water-interaction control the levels of trace elements in this aquifer. Elevated concentrations of Fe, Mn and Se in certain boreholes are due to the geology of the aquifer and probable redox status of groundwater. From PHREEQC speciation results, variations in trace element species were observed. Based on this study, boreholes need constant monitoring and assessment for human consumption to avoid health related issues.

Connecting Teachers and Students to the Natural World through "Operation Spider": An Aspirations Citizen Science Project

ERIC Educational Resources Information Center

Paige, Kathy; Lloyd, David; Zeegers, Yvonne; Roetman, Philip; Daniels, Chris; Hoekman, Brad; Linnell, Lisa; George, Ann-Louise; Szilassy, David

2012-01-01

This paper reports on a year-long citizen science project that focused on improving learning for students identified as most at risk of not succeeding at school. This project was one element of a broader university-based aspirations Initiative which aimed to engage students from low socio-economic schools in rigorous learning in order to increase…

Kinetic determinations of trace element bioaccumulation in the mussel Mytilus edulis

USGS Publications Warehouse

Wang, W.-X.; Fisher, N.S.; Luoma, S.N.

1996-01-01

Laboratory experiments employing radiotracer methodology were conducted to determine the assimilation efficiencies from ingested natural seston, the influx rates from the dissolved phase and the efflux rates of 6 trace elements (Ag, Am, Cd, Co, Se and Zn) in the mussel Mytilus edulis. A kinetic model was then employed to predict trace element concentration in mussel tissues in 2 locations for which mussel and environmental data are well described: South San Francisco Bay (California, USA) and Long Island Sound (New York, USA). Assimilation efficiencies from natural seston ranged from 5 to 18% for Ag, 0.6 to 1% for Am, 8 to 20% for Cd, 12 to 16% for Co, 28 to 34% for Se, and 32 to 41% for Zn. Differences in chlorophyll a concentration in ingested natural seston did not have significant impact on the assimilation of Am, Co, Se and Zn. The influx rate of elements from the dissolved phase increased with the dissolved concentration, conforming to Freundlich adsorption isotherms. The calculated dissolved uptake rate constant was greatest for Ag, followed by Zn > Am = Cd > Co > Se. The estimated absorption efficiency from the dissolved phase was 1.53% for Ag, 0.34% for Am, 0.31% for Cd, 0.11% for Co, 0.03% for Se and 0.89% for Zn. Salinity had an inverse effect on the influx rate from the dissolved phase and dissolved organic carbon concentration had no significant effect on trace element uptake. The calculated efflux rate constants for all elements ranged from 1.0 to 3.0% d-1. The route of trace element uptake (food vs dissolved) and the duration of exposure to dissolved trace elements (12 h vs 6 d) did not significantly influence trace element efflux rates. A model which used the experimentally determined influx and efflux rates for each of the trace elements, following exposure from ingested food and from water, predicted concentrations of Ag, Cd, Se and Zn in mussels that were directly comparable to actual tissue concentrations independently measured in the 2 reference sites in national monitoring programs. Sensitivity analysis indicated that the total suspended solids load, which can affect mussel feeding activity, assimilation, and trace element concentration in the dissolved and particulate phases, can significantly influence metal bioaccumulation for particle-reactive elements such as Ag and Am. For all metals, concentrations in mussels are proportionately related to total metal load in the water column and their assimilation efficiency from ingested particles. Further, the model predicted that over 96% of Se in mussels is obtained from ingested food, under conditions typical of coastal waters. For Ag, Am, Cd, Co and Zn, the relative contribution from the dissolved phase decreases significantly with increasing trace element partition coefficients for suspended particles and the assimilation efficiency in mussels of ingested trace elements; values range between 33 and 67% for Ag, 5 and 17% for Am, 47 and 82% for Cd, 4 and 30% for Co, and 17 and 51% for Zn.

David and Goliath: potent venom of an ant-eating spider (Araneae) enables capture of a giant prey.

PubMed

Pekár, Stano; Šedo, Onřej; Líznarová, Eva; Korenko, Stanislav; Zdráhal, Zdeněk

2014-07-01

It is rare to find a true predator that repeatedly and routinely kills prey larger than itself. A solitary specialised ant-eating spider of the genus Zodarion can capture a relatively giant prey. We studied the trophic niche of this spider species and investigated its adaptations (behavioural and venomic) that are used to capture ants. We found that the spider captures mainly polymorphic Messor arenarius ants. Adult female spiders captured large morphs while tiny juveniles captured smaller morphs, yet in both cases ants were giant in comparison with spider size. All specimens used an effective prey capture strategy that protected them from ant retaliation. Juvenile and adult spiders were able to paralyse their prey using a single bite. The venom glands of adults were more than 50 times larger than those of juvenile spiders, but the paralysis latency of juveniles was 1.5 times longer. This suggests that this spider species possesses very potent venom already at the juvenile stage. Comparison of the venom composition between juvenile and adult spiders did not reveal significant differences. We discovered here that specialised capture combined with very effective venom enables the capture of giant prey.

David and Goliath: potent venom of an ant-eating spider (Araneae) enables capture of a giant prey

NASA Astrophysics Data System (ADS)

Pekár, Stano; Šedo, Onřej; Líznarová, Eva; Korenko, Stanislav; Zdráhal, Zdeněk

2014-07-01

It is rare to find a true predator that repeatedly and routinely kills prey larger than itself. A solitary specialised ant-eating spider of the genus Zodarion can capture a relatively giant prey. We studied the trophic niche of this spider species and investigated its adaptations (behavioural and venomic) that are used to capture ants. We found that the spider captures mainly polymorphic Messor arenarius ants. Adult female spiders captured large morphs while tiny juveniles captured smaller morphs, yet in both cases ants were giant in comparison with spider size. All specimens used an effective prey capture strategy that protected them from ant retaliation. Juvenile and adult spiders were able to paralyse their prey using a single bite. The venom glands of adults were more than 50 times larger than those of juvenile spiders, but the paralysis latency of juveniles was 1.5 times longer. This suggests that this spider species possesses very potent venom already at the juvenile stage. Comparison of the venom composition between juvenile and adult spiders did not reveal significant differences. We discovered here that specialised capture combined with very effective venom enables the capture of giant prey.

Almost a spider: a 305-million-year-old fossil arachnid and spider origins.

PubMed

Garwood, Russell J; Dunlop, Jason A; Selden, Paul A; Spencer, Alan R T; Atwood, Robert C; Vo, Nghia T; Drakopoulos, Michael

2016-03-30

Spiders are an important animal group, with a long history. Details of their origins remain limited, with little knowledge of their stem group, and no insights into the sequence of character acquisition during spider evolution. We describe a new fossil arachnid, Idmonarachne brasierigen. et sp. nov. from the Late Carboniferous (Stephanian,ca 305-299 Ma) of Montceau-les-Mines, France. It is three-dimensionally preserved within a siderite concretion, allowing both laboratory- and synchrotron-based phase-contrast computed tomography reconstruction. The latter is a first for siderite-hosted fossils and has allowed us to investigate fine anatomical details. Although distinctly spider-like in habitus, this remarkable fossil lacks a key diagnostic character of Araneae: spinnerets on the underside of the opisthosoma. It also lacks a flagelliform telson found in the recently recognized, spider-related, Devonian-Permian Uraraneida. Cladistic analysis resolves our new fossil as sister group to the spiders: the spider stem-group comprises the uraraneids and I. brasieri While we are unable to demonstrate the presence of spigots in this fossil, the recovered phylogeny suggests the earliest character to evolve on the spider stem-group is the secretion of silk. This would have been followed by the loss of a flagelliform telson, and then the ability to spin silk using spinnerets. This last innovation defines the true spiders, significantly post-dates the origins of silk, and may be a key to the group's success. The Montceau-les-Mines locality has previously yielded a mesothele spider (with spinnerets). Evidently, Late Palaeozoic spiders lived alongside Palaeozoic arachnid grades which approached the spider condition, but did not express the full suite of crown-group autapomorphies. © 2016 The Authors.

Temporal Patterns in the Abundance and Species Composition of Spiders on Host Plants of the Invasive Moth Epiphyas postvittana (Lepidoptera: Tortricidae).

PubMed

Hogg, Brian N; Mills, Nicholas J; Daane, Kent M

2017-06-01

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 examined whether resident spiders are likely to play a role in maintaining populations of the invasive light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), below outbreak levels in California. We surveyed the spider community on two E. postvittana host plants, the ornamental Australian tea tree, Leptospermum laevigatum, and the weed French broom, Genista monspessulana, to characterize spider and larval E. postvittana abundance and spider species composition throughout the year. Spider densities and species composition showed slight seasonal changes. Spiders were present during periods of high and low E. postvittana abundance. Anyphaenid hunting spiders, Anyphaena aperta Banks in Australian tea tree and Anyphaena pacifica Banks in French broom, dominated spider species composition at four of five sampled sites, and underwent only slight seasonal variation in abundance. Adult A. aperta were rare at all times of the year, suggesting that high mortality among juvenile A. aperta limits the potential of this species as a predator of E. postvittana. Nevertheless, the continued presence of spiders throughout the year indicates that the resident spider community is likely to play a key role in reducing E. postvittana populations in California. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Contributions of detrital subsidies to aboveground spiders during secondary succession, revealed by radiocarbon and stable isotope signatures.

PubMed

Haraguchi, Takashi F; Uchida, Masao; Shibata, Yasuyuki; Tayasu, Ichiro

2013-04-01

Prey subsidies originating from detritus add nutrients and energy to arboreal communities. Measurement of this subsidy is required in the understanding of how food web dynamics respond to changes in surrounding environments. Shrub spiders are one of the key predators involved in food web coupling. We evaluate the effects of potential changes in prey availabilities during secondary succession on the contribution of subsidy from detrital food webs to shrub spiders and how different spider feeding guilds used the subsidy of prey from detrital food webs. We measured the relative importance of the subsidy for the spider feeding guilds, using the ratios of stable isotopes of C (δ(13)C), and N (δ(15)N) and C isotope discrimination (Δ(14)C). Diet age was calculated from Δ(14)C values, because old diet ages of spiders indicate that the spiders consume prey from detrital food sources. Dominant aerial prey (Diptera) had a distinctively old diet age compared with arboreal prey, which indicates that aerial prey were subsidized from detrital food webs. Sit-and-wait spiders tended to have an older diet age than active hunting spiders, which indicates that sit-and-wait spiders depended more on subsidies. Diet age varied only slightly for spiders in stands of different ages, indicating that rates at which spiders use grazing and detrital prey are probably determined more by foraging strategies and not by stand age. A dominance of sit-and-wait predators will lead to higher detrital subsidy inputs in shrub habitats. This study highlights the effect of shrub spider community structure (feeding guild composition) on the volume of the subsidy received from the detrital food web.

Cuticular bacteria appear detrimental to social spiders in mixed but not monoculture exposure

PubMed Central

Keiser, Carl N.; Shearer, Taylor A.; DeMarco, Alexander E.; Brittingham, Hayley A.; Knutson, Karen A.; Kuo, Candice; Zhao, Katherine; Pruitt, Jonathan N.

2016-01-01

Abstract Much of an animal’s health status, life history, and behavior are dictated by interactions with its endogenous and exogenous bacterial communities. Unfortunately, interactions between hosts and members of their resident bacterial community are often ignored in animal behavior and behavioral ecology. Here, we aim to identify the nature of host–microbe interactions in a nonmodel organism, the African social spider Stegodyphus dumicola. We collected and identified bacteria from the cuticles of spiders in situ and then exposed spiders to bacterial monocultures cultures via topical application or injection. We also topically inoculated spiders with a concomitant “cocktail” of bacteria and measured the behavior of spiders daily for 24 days after inoculation. Lastly, we collected and identified bacteria from the cuticles of prey items in the capture webs of spiders, and then fed spiders domestic crickets which had been injected with these bacteria. We also injected 1 species of prey-borne bacteria into the hemolymph of spiders. Only Bacillus thuringiensis caused increased mortality when injected into the hemolymph of spiders, whereas no bacterial monocultures caused increased mortality when applied topically, relative to control solutions. However, a bacterial cocktail of cuticular bacteria caused weight loss and mortality when applied topically, yet did not detectibly alter spider behavior. Consuming prey injected with prey-borne bacteria was associated with an elongated lifespan in spiders. Thus, indirect evidence from multiple experiments suggests that the effects of these bacteria on spider survivorship appear contingent on their mode of colonization and whether they are applied in monoculture or within a mixed cocktail. We urge that follow-up studies should test these host–microbe interactions across different social contexts to determine the role that microbes play in colony performance. PMID:29491926

Co-occurrence profiles of trace elements in potable water systems: a case study.

PubMed

Andra, Syam S; Makris, Konstantinos C; Charisiadis, Pantelis; Costa, Costas N

2014-11-01

Potable water samples (N = 74) from 19 zip code locations in a region of Greece were profiled for 13 trace elements composition using inductively coupled plasma mass spectrometry. The primary objective was to monitor the drinking water quality, while the primary focus was to find novel associations in trace elements occurrence that may further shed light on common links in their occurrence and fate in the pipe scales and corrosion products observed in urban drinking water distribution systems. Except for arsenic at two locations and in six samples, rest of the analyzed elements was below maximum contaminant levels, for which regulatory values are available. Further, we attempted to hierarchically cluster trace elements based on their covariances resulting in two groups; one with arsenic, antimony, zinc, cadmium, and copper and the second with the rest of the elements. The grouping trends were partially explained by elements' similar chemical activities in water, underscoring their potential for co-accumulation and co-mobilization phenomena from pipe scales into finished water. Profiling patterns of trace elements in finished water could be indicative of their load on pipe scales and corrosion products, with a corresponding risk of episodic contaminant release. Speculation was made on the role of disinfectants and disinfection byproducts in mobilizing chemically similar trace elements of human health interest from pipe scales to tap water. It is warranted that further studies may eventually prove useful to water regulators from incorporating the acquired knowledge in the drinking water safety plans.

A simple model for closure temperature of a trace element in cooling bi-mineralic systems

NASA Astrophysics Data System (ADS)

Liang, Yan

2015-09-01

Closure temperature is defined as the lower temperature limit at which the element of interest effectively ceases diffusive exchange with its surrounding medium during cooling. Here we generalize the classic equation of Dodson (1973) for cooling mono-mineralic systems to cooling bi-mineralic aggregates by considering diffusive exchange of a trace element between the two minerals in a closed system. We present a simple analytical model that includes key parameters affecting the closure temperature of a trace element in cooling bi-mineralic systems: cooling rate, temperature-dependent diffusion coefficients for the trace element in the two minerals, temperature-dependent partition coefficient of the trace element between the two minerals, effective grain sizes of the two minerals, and volume proportions of the minerals in the system. We show that closure temperatures of a trace element in cooling bi-mineralic systems are bounded by the closure temperatures of the trace element in the two mono-mineralic systems and that our generalized model reduces to Dodson's equation when one of the mineral serves as "an effective infinite" reservoir to the other mineral. Application to closure temperatures of REE in orthopyroxene and clinopyroxene bi-mineralic systems highlights the importance of REE diffusion and partitioning in the pyroxenes as well as clinopyroxene modal abundance and grain size in the systems. Closure temperatures for REE in two-pyroxene bearing equigranular rocks are controlled primarily by diffusion in orthopyroxene unless the modal abundance of clinopyroxene is very small. This has important bearings on the interpretation of temperatures derived from the REE-in-two-pyroxene thermometer.

Trace elements in hazardous mineral fibres.

PubMed

Bloise, Andrea; Barca, Donatella; Gualtieri, Alessandro Francesco; Pollastri, Simone; Belluso, Elena

2016-09-01

Both occupational and environmental exposure to asbestos-mineral fibres can be associated with lung diseases. The pathogenic effects are related to the dimension, biopersistence and chemical composition of the fibres. In addition to the major mineral elements, mineral fibres contain trace elements and their content may play a role in fibre toxicity. To shed light on the role of trace elements in asbestos carcinogenesis, knowledge on their concentration in asbestos-mineral fibres is mandatory. It is possible that trace elements play a synergetic factor in the pathogenesis of diseases caused by the inhalation of mineral fibres. In this paper, the concentration levels of trace elements from three chrysotile samples, four amphibole asbestos samples (UICC amosite, UICC anthophyllite, UICC crocidolite and tremolite) and fibrous erionite from Jersey, Nevada (USA) were determined using inductively coupled plasma mass spectrometry (ICP-MS). For all samples, the following trace elements were measured: Li, Be, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, As, Rb, Sr, Y, Sb, Cs, Ba, La, Pb, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, U. Their distribution in the various mineral species is thoroughly discussed. The obtained results indicate that the amount of trace metals such as Mn, Cr, Co, Ni, Cu and Zn is higher in anthophyllite and chrysotile samples, whereas the amount of rare earth elements (REE) is higher in erionite and tremolite samples. The results of this work can be useful to the pathologists and biochemists who use asbestos minerals and fibrous erionite in-vitro studies as positive cyto- and geno-toxic standard references. Copyright © 2016 Elsevier Ltd. All rights reserved.

Phytoaccumulation of trace elements by wetland plants: 3. Uptake and accumulation of ten trace elements by twelve plant species

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

Qian, J.H.; Zayed, A.; Zhu, Y.L.

1999-10-01

Interest is increasing in using wetland plants in constructed wetlands to remove toxic elements from polluted wastewater. To identify those wetland plants that hyperaccumulate trace elements, 12 plant species were tested for their efficiency to bioconcentrate 10 potentially toxic trace elements including As, b, Cd, Cr, Cu, Pb, Mn, Hg, Ni, and Se. Individual plants were grown under carefully controlled conditions and supplied with 1 mg L{sup {minus}1} of each trace element individually for 10 d. Except B, all elements accumulated to much higher concentrations in roots than in shoots. Highest shoot tissue concentrations (mg kg{sup {minus}1} DW) of themore » various trace elements were attained by the following species: umbrella plant (Cyperus alternifolius L.) for Mn (198) and Cr (44); water zinnia (Wedelia trilobata Hitchc.) for Cd (148) and Ni (80); smartweed (Polygonum hydropiperoides Michx.) for Cu (95) and Pb (64); water lettuce (Pistia stratiotes L.) for Hg (92), As (34), and Se (39); and mare's tail (hippuris vulgaris L.) for B (1132). Whereas, the following species attained the highest root tissue concentrations (mg kg{sup {minus}1} DW); stripped rush (Baumia rubiginosa) for Mn (1683); parrot's feather (Myriophyllum brasiliense Camb.) for Cd (1426) and Ni (1077); water lettuce for Cu (1038), Hg (1217), and As (177); smartweed for Cr (2980) and Pb (1882); mare's tail for B (1277); and monkey flower (Mimulus guttatus Fisch.) for Se (384). From a phytoremediation perspective, smartweed was probably the best plant species for trace element removal from wastewater due to its faster growth and higher plant density.« less

Spiders in dermatology.

PubMed

Kang, Jun K; Bhate, Chinmoy; Schwartz, Robert A

2014-09-01

Spider bites represent an unusual and potentially over-represented clinical diagnosis. Despite a common fear of spiders, known as arachnophobia, current knowledge suggests that only a small number of families within the order Araneae are medically relevant. Moreover, most cutaneous spider reactions, including both evenomations and physical trauma, produce mild, local symptoms which may be managed with supportive care alone. The differential diagnosis for spider bites may be broad, especially if the offending arachnid is not seen or found. We describe a series of spiders relevant to the dermatologist in the United States.

Sequential patterns of essential trace elements composition in Gracilaria verrucosa and its generated products

NASA Astrophysics Data System (ADS)

Izzati, Munifatul; Haryanti, Sri; Parman, Sarjana

2018-05-01

Gracilaria widely known as a source of essential trace elements. However this red seaweeds also has great potential for being developed into commercial products. This study examined the sequential pattern of essential trace elements composition in fresh Gracilaria verrucosa and a selection of its generated products, nemely extracted agar, Gracilaria salt and Gracilaria residue. The sample was collected from a brackish water pond, located in north part Semarang, Central Java. The collected sample was then dried under the sun, and subsequently processed into aformentioned generated products. The Gracilaria salt was obtain by soaking the sun dried Gracilaria overnight in fresh water overnight. The resulted salt solution was then boiled leaving crystal salt. Extracted agar was obtained with alkali agar extraction method. The rest of remaining material was considered as Gracilaria residue. The entire process was repeated 3 times. The compositin of trace elements was examined using ICP-MS Spectrometry. Collected data was then analyzed by ANOVA single factor. Resulting sequential pattern of its essential trace elements composition was compared. A regular table salt was used as controls. Resuts from this study revealed that Gracilaria verrucosa and its all generated products all have similarly patterned the composition of essential trace elements, where Mn>Zn>Cu>Mo. Additionally this pattern is similar to different subspecies of Gracilaria from different location and and different season. However, Gracilaria salt has distinctly different pattern of sequential essential trace elements composition compared to table salt.

Spider diversity in coffee agroecosystems: the influence of agricultural intensification and aggressive ants.

PubMed

Marín, Linda; Perfecto, Ivette

2013-04-01

Spiders are a very diverse group of invertebrate predators found in agroecosystems and natural systems. However, spider distribution, abundance, and eventually their ecological function in ecosystems can be influenced by abiotic and biotic factors such as agricultural intensification and dominant ants. Here we explore the influence of both agricultural intensification and the dominant arboreal ant Azteca instabilis on the spider community in coffee agroecosystems in southern Mexico. To measure the influence of the arboreal ant Azteca instabilis (F. Smith) on the spider community inhabiting the coffee layer of coffee agroecosystems, spiders were collected from coffee plants that were and were not patrolled by the ant in sites differing in agricultural intensification. For 2008, generalized linear mixed models showed that spider diversity was affected positively by agricultural intensification but not by the ant. However, results suggested that some spider species were associated with A. instabilis. Therefore, in 2009 we concentrated our research on the effect of A. instabilis on spider diversity and composition. For 2009, generalized linear mixed models show that spider richness and abundance per plant were significantly higher in the presence of A. instabilis. In addition, analyses of visual counts of insects and sticky traps data show that more resources were present in plants patrolled by the ant. The positive effect of A. instabilis on spiders seems to be caused by at least two mechanisms: high abundance of insects and protection against predators.

Ant exclusion in citrus over an 8-year period reveals a pervasive yet changing effect of ants on a Mediterranean spider assemblage.

PubMed

Mestre, L; Piñol, J; Barrientos, J A; Espadaler, X

2013-09-01

Ants and spiders are ubiquitous generalist predators that exert top-down control on herbivore populations. Research shows that intraguild interactions between ants and spiders can negatively affect spider populations, but there is a lack of long-term research documenting the strength of such interactions and the potentially different effects of ants on the diverse array of species in a spider assemblage. Similarly, the suitability of family-level surrogates for finding patterns revealed by species-level data (taxonomic sufficiency) has almost never been tested in spider assemblages. We present a long-term study in which we tested the impact of ants on the spider assemblage of a Mediterranean citrus grove by performing sequential 1-year experimental exclusions on tree canopies for 8 years. We found that ants had a widespread influence on the spider assemblage, although the effect was only evident in the last 5 years of the study. During those years, ants negatively affected many spiders, and effects were especially strong for sedentary spiders. Analyses at the family level also detected assemblage differences between treatments, but they concealed the different responses to ant exclusion shown by some related spider species. Our findings show that the effects of experimental manipulations in ecology can vary greatly over time and highlight the need for long-term studies to document species interactions.

Early Diagenesis of Trace Elements in Modern Fjord Sediments of the High Arctic

NASA Astrophysics Data System (ADS)

Herbert, L.; Riedinger, N.; Aller, R. C.; Jørgensen, B. B.; Wehrmann, L.

2017-12-01

Marine sediments are critical repositories for elements that are only available at trace concentrations in seawater, such as Fe, Mn, Co, Ni, As, Mo, and U. The behavior of these trace elements in the sediment is governed by a dynamic interplay of diagenetic reactions involving organic carbon, Fe and Mn oxides, and sulfur phases. In the Arctic fjords of Svalbard, glacial meltwater delivers large amounts of reactive Fe and Mn oxides to the sediment, while organic carbon is deposited episodically and diluted by lithogenic material. These conditions result in pronounced Fe and Mn cycling, which in turn drives other diagenetic processes such as rapid sulfide oxidation. These conditions make the Svalbard fjords ideal sites for investigating trace element diagenesis because they allow resolution of the interconnections between Fe and Mn dynamics and trace element cycling. In August 2016, we collected sediment cores from three Svalbard fjords and analyzed trace elements in the pore water and solid sediment over the top meter. Initial results reveal the dynamic nature of these fjords, which are dominated by non-steady state processes and episodic events such as meltwater pulses and phytoplankton blooms. Within this system, the distribution of As appears to be strongly linked to the Fe cycle, while Co and Ni follow Mn; thus, these three elements may be released from the sediment through diffusion and bioturbation along with Fe and Mn. The pore water profiles of U and Mo indicate removal processes that are independent from Fe or Mn, and which are rather unexpected given the apparent diagenetic conditions. Our results will help elucidate the processes controlling trace element cycling in a dynamic, glacially impacted environment and will ultimately contribute to our understanding of the role of fjords in the biogeochemical cycling of trace elements in a rapidly changing Arctic Ocean.

Trace elements: implications for nursing.

PubMed

Hayter, J

1980-01-01

Although most were unknown a few years ago, present evidence indicates that at least 25 trace elements have some pertinence to health. Unlike vitamins, they cannot be synthesized. Some trace elements are now considered important only because of their harmful effects but traces of them may be essential. Zinc is especially important during puberty, pregnancy and menopause and is related to protein metabolism. Both fluoride and cadmium accumulate in the body year after year. Cadmium is positively correlated with several chronic diseases, especially hypertension. It is obtained from smoking and drinking soft water. Silicon, generally associated with silicosis, may be necessary for healthy bone and connective tissue. Chromium, believed to be the glucose tolerance factor, is obtained from brewer's yeast, spices, and whole wheat products. Copper deficiency may be implicated in a wide range of cardiovascular and blood related disorders. Either marginal deficiencies or slight excesses of most trace elements are harmful. Nurses should instruct patients to avoid highly refined foods, fad diets, or synthetic and fabricated foods. A well balanced and varied diet is the best safeguard against trace element excesses or deficiencies.

Extraordinarily high spider densities on islands: flow of energy from the marine to terrestrial food webs and the absence of predation.

PubMed Central

Polis, G A; Hurd, S D

1995-01-01

Some islands in the Gulf of California support very high densities of spiders. Spider density is negatively correlated with island size; many small islands support 50-200 spiders per m3 of cactus. Energy for these spiders comes primarily from the ocean and not from in situ productivity by land plants. We explicitly connect the marine and terrestrial systems to show that insular food webs represent one endpoint of the marine web. We describe two conduits for marine energy entering these islands: shore drift and seabird colonies. Both conduits are related to island area, having a much stronger effect on smaller islands. This asymmetric effect helps to explain the exceptionally high spider densities on small islands. Although productivity sets the maximal potential densities, predation (by scorpions) limits realized spider abundance. Thus, prey availability and predation act in concert to set insular spider abundance. PMID:7753815

Resistance of Cultivated Tomato to Cell Content-Feeding Herbivores Is Regulated by the Octadecanoid-Signaling Pathway1

PubMed Central

Li, Chuanyou; Williams, Mark M.; Loh, Ying-Tsu; Lee, Gyu In; Howe, Gregg A.

2002-01-01

The octadecanoid signaling pathway has been shown to play an important role in plant defense against various chewing insects and some pathogenic fungi. Here, we examined the interaction of a cell-content feeding arachnid herbivore, the two-spotted spider mite (Tetranychus urticae Koch), with cultivated tomato (Lycopersicon esculentum) and an isogenic mutant line (defenseless-1 [def-1]) that is deficient in the biosynthesis of the octadecanoid pathway-derived signal, jasmonic acid (JA). Spider mite feeding and fecundity on def-1 plants was significantly greater than on wild-type plants. Decreased resistance of def-1 plants was correlated with reduced JA accumulation and expression of defensive proteinase inhibitor (PI) genes, which were induced in mite-damaged wild-type leaves. Treatment of def-1 plants with methyl-JA restored resistance to spider mite feeding and reduced the fecundity of female mites. Plants expressing a 35S::prosystemin transgene that constitutively activates the octadecanoid pathway in a Def-1-dependent manner were highly resistant to attack by spider mites and western flower thrips (Frankliniella occidentalis), another cell-content feeder of economic importance. These findings indicate that activation of the octadecanoid signaling pathway promotes resistance of tomato to a broad spectrum of herbivores. The techniques of amplified fragment length polymorphism (AFLP) and bulk segregant analysis were used to map the Def-1 gene to a region on the long arm of chromosome 3 that is genetically separable from the map position of known JA biosynthetic genes. Tight linkage of Def-1 to a T-DNA insertion harboring the maize (Zea mays) Dissociation transposable element suggests a strategy for directed transposon tagging of the gene. PMID:12226528

Survival ability of Mexican fruit fly males from different strains in presence of the predatory orb-weaving spider Argiope argentata (Araneae: Araneidae).

PubMed

Dor, A; Liedo, P

2018-04-18

The sterile insect technique (SIT) is a key element for the integrated management of pest populations of the Mexican fruit fly, Anastrepha ludens, in Mexico. Its success depends on the survival of mass-reared sterile males and their ability to mate with wild females. However, colonization and mass-rearing conditions can adversely affect their ability to avoid predators. To test if colony management strategies could contribute to improve field survival abilities of mass-reared flies, we compared the survival of males exposed to the orb-weaver spider Argiope argentata. Males compared originated from three strains with different colonization strategies: (a) a colony started from field-collected wild flies (replacement), (b) a colony started by hybridizing wild males with mass-reared adapted females (hybrid) and (c) a colony started with mass-reared males selected on the basis of their survival ability and mating competitiveness in field cages (selected). Mass-reared males and wild males were used as controls. Males were exposed to spiders under laboratory cage conditions. Overall, wild males showed better survival ability than mass-reared males. Regarding the colonization approach, wild males survived better than a hybrid, replaced and selected males. We conclude that mass-rearing conditions have a strong negative effect on the ability of males to escape spiders. The colonization systems evaluated did not counter this effect. The lower survival of males from the selected colony suggests that the selection over one generation did not contribute to improve males' predator avoidance and escape abilities and probably needs to be modified. Possible explanations for this and implications on colonization and colony management for SIT purpose are discussed.

Three-dimensional printing spiders: back-and-forth glue application yields silk anchorages with high pull-off resistance under varying loading situations

PubMed Central

Herberstein, Marie E.

2017-01-01

The anchorage of structures is a crucial element of construction, both for humans and animals. Spiders use adhesive plaques to attach silk threads to substrates. Both biological and artificial adhesive structures usually have an optimal loading angle, and are prone to varying loading situations. Silk anchorages, however, must cope with loading in highly variable directions. Here we show that the detachment forces of thread anchorages of orb-web spiders are highly robust against pulling in different directions. This is gained by a two-step back-and-forth spinning pattern during the rapid production of the adhesive plaque, which shifts the thread insertion point towards the plaque centre and forms a flexible tree root-like network of branching fibres around the loading point. Using a morphometric approach and a tape-and-thread model we show that neither area, nor width of the plaque, but the shift of the loading point towards the plaque centre has the highest effect on pull-off resistance. This is explained by a circular propagation of the delamination crack with a low peeling angle. We further show that silken attachment discs are highly directional and adjusted to provide maximal performance in the upstream dragline. These results show that the way the glue is applied, crucially enhances the toughness of the anchorage without the need of additional material intake. This work is a starting point to study the evolution of tough and universal thread anchorages among spiders, and to develop bioinspired ‘instant’ anchorages of thread- and cable-like structures to a broad bandwidth of substrates. PMID:28228539

Three-dimensional printing spiders: back-and-forth glue application yields silk anchorages with high pull-off resistance under varying loading situations.

PubMed

Wolff, Jonas O; Herberstein, Marie E

2017-02-01

The anchorage of structures is a crucial element of construction, both for humans and animals. Spiders use adhesive plaques to attach silk threads to substrates. Both biological and artificial adhesive structures usually have an optimal loading angle, and are prone to varying loading situations. Silk anchorages, however, must cope with loading in highly variable directions. Here we show that the detachment forces of thread anchorages of orb-web spiders are highly robust against pulling in different directions. This is gained by a two-step back-and-forth spinning pattern during the rapid production of the adhesive plaque, which shifts the thread insertion point towards the plaque centre and forms a flexible tree root-like network of branching fibres around the loading point. Using a morphometric approach and a tape-and-thread model we show that neither area, nor width of the plaque, but the shift of the loading point towards the plaque centre has the highest effect on pull-off resistance. This is explained by a circular propagation of the delamination crack with a low peeling angle. We further show that silken attachment discs are highly directional and adjusted to provide maximal performance in the upstream dragline. These results show that the way the glue is applied, crucially enhances the toughness of the anchorage without the need of additional material intake. This work is a starting point to study the evolution of tough and universal thread anchorages among spiders, and to develop bioinspired 'instant' anchorages of thread- and cable-like structures to a broad bandwidth of substrates. © 2017 The Author(s).

Lachesana tarabaevi, an expert in membrane-active toxins.

PubMed

Kuzmenkov, Alexey I; Sachkova, Maria Y; Kovalchuk, Sergey I; Grishin, Eugene V; Vassilevski, Alexander A

2016-08-15

In the present study, we show that venom of the ant spider Lachesana tarabaevi is unique in terms of molecular composition and toxicity. Whereas venom of most spiders studied is rich in disulfide-containing neurotoxic peptides, L. tarabaevi relies on the production of linear (no disulfide bridges) cytolytic polypeptides. We performed full-scale peptidomic examination of L. tarabaevi venom supported by cDNA library analysis. As a result, we identified several dozen components, and a majority (∼80% of total venom protein) exhibited membrane-active properties. In total, 33 membrane-interacting polypeptides (length of 18-79 amino acid residues) comprise five major groups: repetitive polypeptide elements (Rpe), latarcins (Ltc), met-lysines (MLys), cyto-insectotoxins (CIT) and latartoxins (LtTx). Rpe are short (18 residues) amphiphilic molecules that are encoded by the same genes as antimicrobial peptides Ltc 4a and 4b. Isolation of Rpe confirms the validity of the iPQM (inverted processing quadruplet motif) proposed to mark the cleavage sites in spider toxin precursors that are processed into several mature chains. MLys (51 residues) present 'idealized' amphiphilicity when modelled in a helical wheel projection with sharply demarcated sectors of hydrophobic, cationic and anionic residues. Four families of CIT (61-79 residues) are the primary weapon of the spider, accounting for its venom toxicity. Toxins from the CIT 1 and 2 families have a modular structure consisting of two shorter Ltc-like peptides. We demonstrate that in CIT 1a, these two parts act in synergy when they are covalently linked. This finding supports the assumption that CIT have evolved through the joining of two shorter membrane-active peptides into one larger molecule. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Trace element diffusion and kinetic fractionation in wet rhyolitic melt

NASA Astrophysics Data System (ADS)

Holycross, Megan E.; Watson, E. Bruce

2018-07-01

Piston-cylinder experiments were run to determine the chemical diffusivities of 21 trace elements (Sc, V, Y, Zr, Nb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Hf, Th and U) in hydrous rhyolitic melts at 1 GPa pressure and temperatures from 850 to 1250 °C. Diffusion couple glasses were doped with trace elements in low concentrations to characterize the diffusivities of all cations in a single experiment. Laser ablation ICP-MS was used to evaluate the trace element concentration gradients that developed in the silicate glasses. All calculated diffusion coefficients correspond to the temperature dependence D = D0exp(-Ea/RT). Rhyolite liquids contained either ∼4.1 wt% or ∼6.2 wt% dissolved H2O; separate Arrhenius relationships are produced for each melt composition. Trace element diffusivities in the melt with 6.2 wt% H2O are roughly two times higher than those in the less hydrous melt. Calculated trace element diffusion coefficients cover nearly two orders of magnitude at a given temperature. The high field strength elements are the slowest diffusers, followed by the transition metals and heavy rare earth elements. The light rare earth elements have the fastest diffusion rates in hydrous rhyolitic melt. The measured diffusion coefficients range down to values sufficiently low to preclude diffusive homogenization over geochemically realistic time scales in some cases. The substantial differences in the diffusivities of individual cations may result in fractionated trace element signatures in rhyolite melt pockets. A simple model is used to explore the potential for kinetic fractionation of REE during growth of an apatite crystal in a diffusive boundary layer locally saturated in P2O5. The faster-diffusing light REE are more efficiently transported away from the crystal interface than the slower-moving heavy REE. Diffusion effects will enrich the melt boundary layer in slow-moving HREE relative to the faster LREE. The kinetic fractionation of REE in the melt growth medium will result in a precipitated apatite crystal with a disequilibrium trace element composition.

Dynamics of trace elements in shallow groundwater of an agricultural land in the northeast of Mexico

NASA Astrophysics Data System (ADS)

Mora, Abrahan; Mahlknecht, Jürgen; Hernández-Antonio, Arturo

2017-04-01

The citrus zone located in northeastern Mexico covers an area of 8000 km2 and produces 10% of the Mexican citrus production. The aquifer system of this zone constitutes the major source of water for drinking and irrigation purposes for local population and provides base flows to surface water supplied to the city of Monterrey ( 4.5 million inhabitants). Although the study area is near the recharge zones, several works have reported nitrate pollution in shallow groundwater of this agricultural area, mainly due to animal manure and human waste produced by infiltration of urban sewers and septic tanks. Thus, the goals of this work were to assess the dynamics of selected trace elements in this aquifer system and determine if the trace element content in groundwater poses a threat to the population living in the area. Thirty-nine shallow water wells were sampled in 2010. These water samples were filtered through 0,45 µm pore size membranes and preserved with nitric acid for storage. The concentrations of Cd, Cs, Cu, Mo, Pb, Rb, Si, Ti, U, Y, and Zn were measured by ICP-MS. Also, sulfate concentrations were measured by ion chromatography in unacidified samples. Principal Component Analysis (PCA) performed in the data set show five principal components (PC). PC1 includes elements derived from silicate weathering, such as Si and Ti. The relationship found between Mo and U with sulfates in PC2 indicates that both elements show a high mobility in groundwater. Indeed, the concentrations of sulfate, Mo and U are increased as groundwater moves eastward. PC3 includes the alkali trace elements (Rb and Cs), indicating that both elements could be derived from the same source of origin. PC4 represents the heavy trace elements (Cd and Pb) whereas PC5 includes divalent trace elements such as Zn and Cu. None of the water samples showed trace element concentrations higher than the guideline values for drinking water proposed by the World Health Organization, which indicates that the analyzed trace elements in groundwater do not pose any significant threat to the population living in this area.

Science 101: Why Don't Spiders Stick to Their Own Webs?

ERIC Educational Resources Information Center

Robertson, Bill

2011-01-01

This article explains why spiders don't stick to their webs. Spiders don't get stuck in their own webs (and they aren't immune to their own glue) because they use a combination of sticky and nonsticky threads (different glands for producing those), and the glue is in droplets that the spider can avoid but the prey can't. The spider's nervous…

Trace Elements and Health

ERIC Educational Resources Information Center

Pettyjohn, Wayne A.

1972-01-01

Summarizes the effects of arsenic, lead, zinc, mercury, and cadmium on human health, indicates the sources of the elements in water, and considers the possibility of students in high schools analyzing water for trace amounts of the elements. (AL)

Disentangling the phylogenetic and ecological components of spider phenotypic variation.

PubMed

Gonçalves-Souza, Thiago; Diniz-Filho, José Alexandre Felizola; Romero, Gustavo Quevedo

2014-01-01

An understanding of how the degree of phylogenetic relatedness influences the ecological similarity among species is crucial to inferring the mechanisms governing the assembly of communities. We evaluated the relative importance of spider phylogenetic relationships and ecological niche (plant morphological variables) to the variation in spider body size and shape by comparing spiders at different scales: (i) between bromeliads and dicot plants (i.e., habitat scale) and (ii) among bromeliads with distinct architectural features (i.e., microhabitat scale). We partitioned the interspecific variation in body size and shape into phylogenetic (that express trait values as expected by phylogenetic relationships among species) and ecological components (that express trait values independent of phylogenetic relationships). At the habitat scale, bromeliad spiders were larger and flatter than spiders associated with the surrounding dicots. At this scale, plant morphology sorted out close related spiders. Our results showed that spider flatness is phylogenetically clustered at the habitat scale, whereas it is phylogenetically overdispersed at the microhabitat scale, although phylogenic signal is present in both scales. Taken together, these results suggest that whereas at the habitat scale selective colonization affect spider body size and shape, at fine scales both selective colonization and adaptive evolution determine spider body shape. By partitioning the phylogenetic and ecological components of phenotypic variation, we were able to disentangle the evolutionary history of distinct spider traits and show that plant architecture plays a role in the evolution of spider body size and shape. We also discussed the relevance in considering multiple scales when studying phylogenetic community structure.

Disentangling the Phylogenetic and Ecological Components of Spider Phenotypic Variation

PubMed Central

Gonçalves-Souza, Thiago; Diniz-Filho, José Alexandre Felizola; Romero, Gustavo Quevedo

2014-01-01

An understanding of how the degree of phylogenetic relatedness influences the ecological similarity among species is crucial to inferring the mechanisms governing the assembly of communities. We evaluated the relative importance of spider phylogenetic relationships and ecological niche (plant morphological variables) to the variation in spider body size and shape by comparing spiders at different scales: (i) between bromeliads and dicot plants (i.e., habitat scale) and (ii) among bromeliads with distinct architectural features (i.e., microhabitat scale). We partitioned the interspecific variation in body size and shape into phylogenetic (that express trait values as expected by phylogenetic relationships among species) and ecological components (that express trait values independent of phylogenetic relationships). At the habitat scale, bromeliad spiders were larger and flatter than spiders associated with the surrounding dicots. At this scale, plant morphology sorted out close related spiders. Our results showed that spider flatness is phylogenetically clustered at the habitat scale, whereas it is phylogenetically overdispersed at the microhabitat scale, although phylogenic signal is present in both scales. Taken together, these results suggest that whereas at the habitat scale selective colonization affect spider body size and shape, at fine scales both selective colonization and adaptive evolution determine spider body shape. By partitioning the phylogenetic and ecological components of phenotypic variation, we were able to disentangle the evolutionary history of distinct spider traits and show that plant architecture plays a role in the evolution of spider body size and shape. We also discussed the relevance in considering multiple scales when studying phylogenetic community structure. PMID:24651264

Time till death affects spider mobility and web-building behavior during web construction in an orb-web spider

PubMed Central

Anotaux, Mylène; Toscani, Camille; Leborgne, Raymond; Chaline, Nicolas; Pasquet, Alain

2016-01-01

Abstract It is well known that age influences organism mobility. This was demonstrated in vertebrates (such as mammals and birds) but has been less studied in invertebrates with the exception of Drosophila and the nematode Caenorhabditis elegans. Here we studied the influence of age on the mobility of the orb-weaving spider Zygiella x-notata during web construction. The orb-web is a good model because it has a characteristic geometrical structure and video tracking can be used to easily follow the spider’s movements during web building. We investigated the influence of age (specifically chronological age, life span, and time till death) on different parameters of spider mobility during the construction of the capture spiral (distance traveled, duration of construction, spider velocity, spider movement, and spider inactivity) with a generalized linear model (GLM) procedure adjusted for the spider mass. The results showed that neither chronological age, nor life span affected the mobility parameters. However, when the time till death decreased, there was a decrease in the distance traveled, the duration of the construction of the capture spiral, and the spider movement. The spider velocity and the time of inactivity were not affected. These results could be correlated with a decrease in the length of the silky thread deposited for the construction of the capture spiral. Spiders with a shorter time till death built smaller web using less silk. Thus, our study suggests strongly that time till death affects spider mobility during web construction but not the chronological age and thus may be a good indicator of senescence. PMID:29491899

Trace Element Levels and Cognitive Function in Rural Elderly Chinese

PubMed Central

Gao, Sujuan; Jin, Yinlong; Unverzagt, Frederick W.; Ma, Feng; Hall, Kathleen S.; Murrell, Jill R.; Cheng, Yibin; Shen, Jianzhao; Ying, Bo; Ji, Rongdi; Matesan, Janetta; Liang, Chaoke; Hendrie, Hugh C.

2009-01-01

Background Trace elements are involved in metabolic processes and oxidation-reduction reactions in the central nervous system and could have a possible effect on cognitive function. The relationship between trace elements measured in individual biological samples and cognitive function in an elderly population had not been investigated extensively. Methods The participant population is part of a large cohort study of 2000 rural elderly Chinese persons. Six cognitive assessment tests were used to evaluate cognitive function in this population, and a composite score was created to represent global cognitive function. Trace element levels of aluminum, calcium, cadmium, copper, iron, lead, and zinc were analyzed in plasma samples of 188 individuals who were randomly selected and consented to donating fasting blood. Analysis of covariance models were used to assess the association between each trace element and the composite cognitive score adjusting for demographics, medical history of chronic diseases, and the apolipoprotein E (APOE) genotype. Results Three trace elements—calcium, cadmium, and copper—were found to be significantly related to the composite cognitive score. Increasing plasma calcium level was associated with higher cognitive score (p < .0001). Increasing cadmium and copper, in contrast, were significantly associated with lower composite score (p = .0044 and p = .0121, respectively). Other trace elements did not show significant association with the composite cognitive score. Conclusions Our results suggest that calcium, cadmium, and copper may be associated with cognitive function in the elderly population. PMID:18559640

Transport of trace metals in runoff from soil and pond ash feedlot surfaces

USGS Publications Warehouse

Vogel, J.R.; Gilley, J.E.; Cottrell, G.L.; Woodbury, B.L.; Berry, E.D.; Eigenbert, R.A.

2011-01-01

The use of pond ash (fly ash that has been placed in evaporative ponds for storage and subsequently dewatered) for feedlot surfaces provides a drier environment for livestock and furnishes economic benefits. However, pond ash is known to have high concentrations of trace elements, and the runoff water-quality effects of feedlot surfaces amended with pond ash are not well defined. For this study, two experimental units (plots) were established in eight feedlot pens. Four of the pens contained unamended soil surfaces, and the remaining four pens had pond-ash amended surfaces. Before each test, unconsolidated surface material was removed from four of the plots for each of the amendment treatments, resulting in eight unamended plots and eight pond-ash amended plots. Concentrations for 23 trace elements were measured in cattle feedlot surface material and in the runoff water from three simulated rainfall events. Trace element concentrations in surface material and runoff did not differ between surface consolidation treatments. Amending the feedlot surface material with pond ash resulted in a significant increase in concentration for 14 of the 17 trace elements. Runoff concentrations for 21 trace elements were affected by pond-ash amendment. Sixteen of 21 trace element concentrations that differed significantly were greater in runoff from unamended soil surfaces. Concentrations in runoff were significantly correlated with concentrations in feedlot surface material for boron, manganese, molybdenum, selenium, and uranium.

Northern range expansion of European populations of the wasp spider Argiope bruennichi is associated with global warming-correlated genetic admixture and population-specific temperature adaptations.

PubMed

Krehenwinkel, Henrik; Tautz, Diethard

2013-04-01

Poleward range expansions are observed for an increasing number of species, which may be an effect of global warming during the past decades. However, it is still not clear in how far these expansions reflect simple geographical shifts of species ranges, or whether new genetic adaptations play a role as well. Here, we analyse the expansion of the wasp spider Argiope bruennichi into Northern Europe during the last century. We have used a range-wide sampling of contemporary populations and historical specimens from museums to trace the phylogeography and genetic changes associated with the range shift. Based on the analysis of mitochondrial, microsatellite and SNP markers, we observe a higher level of genetic diversity in the expanding populations, apparently due to admixture of formerly isolated lineages. Using reciprocal transplant experiments for testing overwintering tolerance, as well as temperature preference and tolerance tests in the laboratory, we find that the invading spiders have possibly shifted their temperature niche. This may be a key adaptation for survival in Northern latitudes. The museum samples allow a reconstruction of the invasion's genetic history. A first, small-scale range shift started around 1930, in parallel with the onset of global warming. A more massive invasion of Northern Europe associated with genetic admixture and morphological changes occurred in later decades. We suggest that the latter range expansion into far Northern latitudes may be a consequence of the admixture that provided the genetic material for adaptations to new environmental regimes. Hence, global warming could have facilitated the initial admixture of populations and this resulted in genetic lineages with new habitat preferences. © 2013 Blackwell Publishing Ltd.

Occurrence and distribution of trace elements in snow, streams, and streambed sediments, Cape Krusenstern National Monument, Alaska, 2002-2003

USGS Publications Warehouse

Brabets, Timothy P.

2004-01-01

Cape Krusenstern National Monument is located in Northwest Alaska. In 1985, an exchange of lands and interests in lands between the Northwest Alaska Native Association and the United States resulted in a 100-year transportation system easement for 19,747 acres in the monument. A road was then constructed along the easement from the Red Dog Mine, a large zinc concentrate producer and located northeast of the monument, through the monument to the coast and a port facility. Each year approximately 1.3 million tonnes of zinc and lead concentrate are transported from the Red Dog Mine via this access road. Concern about the possible deposition of cadmium, lead, zinc and other trace elements in the monument was the basis of a cooperative project with the National Park Service. Concentrations of dissolved cadmium, dissolved lead, and dissolved zinc from 28 snow samples from a 28 mile by 16 mile grid were below drinking water standards. In the particulate phase, approximately 25 percent of the samples analyzed for these trace elements were higher than the typical range found in Alaska soils. Boxplots of concentrations of these trace elements, both in the dissolved and particulate phase, indicate higher concentrations north of the access road, most likely due to the prevailing southeast wind. The waters of four streams sampled in Cape Krusenstern National Monument are classified as calcium bicarbonate. Trace-element concentrations from these streams were below drinking water standards. Median concentrations of 39 trace elements from streambed sediments collected from 29 sites are similar to the median concentrations of trace elements from the U.S. Geological Survey?s National Water-Quality Assessment database. Statistical differences were noted between trace-element concentrations of cadmium, lead, and zinc at sites along the access road and sites north and south of the access road; concentrations along the access road being higher than north or south of the road. When normalized to 1 percent organic carbon, the concentrations of these trace elements are not expected to be toxic to aquatic life when compared to criteria established by the Canadian government and other recent research.

Spider foraging strategy affects trophic cascades under natural and drought conditions.

PubMed

Liu, Shengjie; Chen, Jin; Gan, Wenjin; Schaefer, Douglas; Gan, Jianmin; Yang, Xiaodong

2015-07-23

Spiders can cause trophic cascades affecting litter decomposition rates. However, it remains unclear how spiders with different foraging strategies influence faunal communities, or present cascading effects on decomposition. Furthermore, increased dry periods predicted in future climates will likely have important consequences for trophic interactions in detritus-based food webs. We investigated independent and interactive effects of spider predation and drought on litter decomposition in a tropical forest floor. We manipulated densities of dominant spiders with actively hunting or sit-and-wait foraging strategies in microcosms which mimicked the tropical-forest floor. We found a positive trophic cascade on litter decomposition was triggered by actively hunting spiders under ambient rainfall, but sit-and-wait spiders did not cause this. The drought treatment reversed the effect of actively hunting spiders on litter decomposition. Under drought conditions, we observed negative trophic cascade effects on litter decomposition in all three spider treatments. Thus, reduced rainfall can alter predator-induced indirect effects on lower trophic levels and ecosystem processes, and is an example of how such changes may alter trophic cascades in detritus-based webs of tropical forests.

Spider foraging strategy affects trophic cascades under natural and drought conditions

PubMed Central

Liu, Shengjie; Chen, Jin; Gan, Wenjin; Schaefer, Douglas; Gan, Jianmin; Yang, Xiaodong

2015-01-01

Spiders can cause trophic cascades affecting litter decomposition rates. However, it remains unclear how spiders with different foraging strategies influence faunal communities, or present cascading effects on decomposition. Furthermore, increased dry periods predicted in future climates will likely have important consequences for trophic interactions in detritus-based food webs. We investigated independent and interactive effects of spider predation and drought on litter decomposition in a tropical forest floor. We manipulated densities of dominant spiders with actively hunting or sit-and-wait foraging strategies in microcosms which mimicked the tropical-forest floor. We found a positive trophic cascade on litter decomposition was triggered by actively hunting spiders under ambient rainfall, but sit-and-wait spiders did not cause this. The drought treatment reversed the effect of actively hunting spiders on litter decomposition. Under drought conditions, we observed negative trophic cascade effects on litter decomposition in all three spider treatments. Thus, reduced rainfall can alter predator-induced indirect effects on lower trophic levels and ecosystem processes, and is an example of how such changes may alter trophic cascades in detritus-based webs of tropical forests. PMID:26202370

Use of local cues in the night-time navigation of the wandering desert spider Leucorchestris arenicola (Araneae, Sparassidae).

PubMed

Nørgaard, Thomas; Henschel, Joh R; Wehner, Rüdiger

2007-02-01

Adult male Leucorchestris arenicola can walk round-trips of several tens of meters in search of females. Most excursions end with the spiders returning to their burrow. For small animals homing over distances of several meters is theoretically impossible without the aid of external cues. It was investigated, whether the spiders use local cues or they rely solely on global cues. Individually marked male spiders were captured during their excursions and displaced several meters inside an opaque box. Ten out of twelve displaced spiders returned to their burrows. This shows that the male L. arenicola are using local cues during their homing, as the comparatively small displacement distances could not be detected by means of global, e.g. celestial cues. In order to test whether the spiders could be using olfactory guidance, the burrows were displaced by 2 m while the spiders were out on their journeys. In 12 out of 15 experiments, the spiders did not find their burrows. These results show that the burrows do not function as olfactory beacons for the homing spiders.

High-Toughness Silk Produced by a Transgenic Silkworm Expressing Spider (Araneus ventricosus) Dragline Silk Protein

PubMed Central

Kuwana, Yoshihiko; Sezutsu, Hideki; Nakajima, Ken-ichi; Tamada, Yasushi; Kojima, Katsura

2014-01-01

Spider dragline silk is a natural fiber that has excellent tensile properties; however, it is difficult to produce artificially as a long, strong fiber. Here, the spider (Araneus ventricosus) dragline protein gene was cloned and a transgenic silkworm was generated, that expressed the fusion protein of the fibroin heavy chain and spider dragline protein in cocoon silk. The spider silk protein content ranged from 0.37 to 0.61% w/w (1.4–2.4 mol%) native silkworm fibroin. Using a good silk-producing strain, C515, as the transgenic silkworm can make the raw silk from its cocoons for the first time. The tensile characteristics (toughness) of the raw silk improved by 53% after the introduction of spider dragline silk protein; the improvement depended on the quantity of the expressed spider dragline protein. To demonstrate the commercial feasibility for machine reeling, weaving, and sewing, we used the transgenic spider silk to weave a vest and scarf; this was the first application of spider silk fibers from transgenic silkworms. PMID:25162624

Evidence for competition between carnivorous plants and spiders.

PubMed

Jennings, David E; Krupa, James J; Raffel, Thomas R; Rohr, Jason R

2010-10-07

Several studies have demonstrated that competition between disparate taxa can be important in determining community structure, yet surprisingly, to our knowledge, no quantitative studies have been conducted on competition between carnivorous plants and animals. To examine potential competition between these taxa, we studied dietary and microhabitat overlap between pink sundews (Drosera capillaris) and wolf spiders (Lycosidae) in the field, and conducted a laboratory experiment examining the effects of wolf spiders on sundew fitness. In the field, we found that sundews and spiders had a high dietary overlap with each other and with the available arthropod prey. Associations between sundews and spiders depended on spatial scale: both sundews and spiders were found more frequently in quadrats with more abundant prey, but within quadrats, spiders constructed larger webs and located them further away from sundews as the total sundew trapping area increased, presumably to reduce competition. Spiders also constructed larger webs when fewer prey were available. In the laboratory, our experiment revealed that spiders can significantly reduce sundew fitness. Our findings suggest that members of the plant and animal kingdoms can and do compete.

High-toughness silk produced by a transgenic silkworm expressing spider (Araneus ventricosus) dragline silk protein.

PubMed

Kuwana, Yoshihiko; Sezutsu, Hideki; Nakajima, Ken-ichi; Tamada, Yasushi; Kojima, Katsura

2014-01-01

Spider dragline silk is a natural fiber that has excellent tensile properties; however, it is difficult to produce artificially as a long, strong fiber. Here, the spider (Araneus ventricosus) dragline protein gene was cloned and a transgenic silkworm was generated, that expressed the fusion protein of the fibroin heavy chain and spider dragline protein in cocoon silk. The spider silk protein content ranged from 0.37 to 0.61% w/w (1.4-2.4 mol%) native silkworm fibroin. Using a good silk-producing strain, C515, as the transgenic silkworm can make the raw silk from its cocoons for the first time. The tensile characteristics (toughness) of the raw silk improved by 53% after the introduction of spider dragline silk protein; the improvement depended on the quantity of the expressed spider dragline protein. To demonstrate the commercial feasibility for machine reeling, weaving, and sewing, we used the transgenic spider silk to weave a vest and scarf; this was the first application of spider silk fibers from transgenic silkworms.

[Analysis of primary elemental speciation distribution in mungbean during enzymatic hydrolization].

PubMed

Li, Ji-Hua; Huang, Mao-Fang; Zhu, De-Ming; Zheng, Wei-Wan; Zhong, Ye-Jun

2009-03-01

In the present paper, trace elements contents of cuprum, zincum, manganese and ferrum in mungbean and their primary speciation distribution during enzymatic hydrolization were investigated with ICP-AES OPTIMA 5300DV plasma emission spectroscopy. The trace elements were separated into two forms, i.e. dissolvable form and particulate form, by cellulose membrane with 0.45 microm of pore diameter. All the samples were digested by strong acid (perchloric acid and nitric acid with 1 : 4 ratio ). The parameters of primary speciations of the four elements were calculated and discussed. The results showed: (1) Contents of cuprum, zincum, manganese and ferrum in mungbean were 12.77, 31.26, 18.14 and 69.38 microg x g(-1) (of dry matter), respectively. Different treatment resulted in different elemental formulation in product, indicating that more attention should be paid to the trace elements pattern when producing mungbean beverage with different processes. (2) Extraction rates of cuprum, zincum, manganese and ferrum in extract were 68.84%, 51.84%, 63.97% and 30.40% with enzymatic treatments and 36.22%, 17.58%, 7.85% and 22.99% with boil treatment, respectively. Both boil and enzymatic treatments led to poor elemental extraction rates, which proved that it was necessary to take deep enzymatic hydrolysis treatment in mungbean beverage process as the trace element utilization rate was concerned. (3) Amylase, protease and cellulose showed different extraction effectiveness of the four trace elements. Generally, protease exhibited highest efficiency for the four elements extraction. All of the four trace elements were mostly in dissolvable form in all hydrolysates and soup. (4) Relative standard deviations and recovery yields are within 0.12%-0.90% (n = 11) and 98.6%-101.4%, respectively. The analysis method in this paper proved to be accurate.

Risk assessment of trace metals in an extreme environment sediment: shallow, hypersaline, alkaline, and industrial Lake Acıgöl, Denizli, Turkey.

PubMed

Budakoglu, Murat; Karaman, Muhittin; Kumral, Mustafa; Zeytuncu, Bihter; Doner, Zeynep; Yildirim, Demet Kiran; Taşdelen, Suat; Bülbül, Ali; Gumus, Lokman

2018-02-23

The major and trace element component of 48 recent sediment samples in three distinct intervals (0-10, 10-20, and 20-30 cm) from Lake Acıgöl is described to present the current contamination levels and grift structure of detrital and evaporate mineral patterns of these sediments in this extreme saline environment. The spatial and vertical concentrations of major oxides were not uniform in the each subsurface interval. However, similar spatial distribution patterns were observed for some major element couples, due mainly to the detrital and evaporate origin of these elements. A sequential extraction procedure including five distinct steps was also performed to determine the different bonds of trace elements in the < 60-μ particulate size of recent sediments. Eleven trace elements (Ni, Fe, Cd, Pb, Cu, Zn, As, Co, Cr, Al and Mn) in nine surface and subsurface sediment samples were analyzed with chemical partitioning procedures to determine the trace element percentage loads in these different sequential extraction phases. The obtained accuracy values via comparison of the bulk trace metal loads with the total loads of five extraction steps were satisfying for the Ni, Fe, Cd, Zn, and Co. While, bulk analysis results of the Cu, Ni, and V elements have good correlation with total organic matter, organic fraction of sequential extraction characterized by Cu, As, Cd, and Pb. Shallow Lake Acıgöl sediment is characteristic with two different redox layer a) oxic upper level sediments, where trace metals are mobilized, b) reduced subsurface level, where the trace metals are precipitated.

Igneous fractionation and subsolidus equilibration of diogenite meteorites

NASA Technical Reports Server (NTRS)

Mittlefehldt, David W.

1993-01-01

Diogenites are coarse-grained orthopyroxenite breccias of remarkably uniform major element composition. Most diogenites contain homogeneous pyroxene fragments up to 5 cm across of Wo2En74Fs24 composition. Common minor constituents are chromite, olivine, trolite and metal, while silica, plagioclase, merrillite and diopside are trace phases. Diogenites are generally believed to be cumulates from the eucrite parent body, although their relationship with eucrites remains obscure. It has been suggested that some diogenites are residues after partial melting. I have performed EMPA and INAA for major, minor and trace elements on most diogenites, concentrating on coarse-grained mineral and lithic clasts in order to elucidate their igneous formation and subsequent metamorphic history. Major element compositions of diogenites are decoupled from minor and trace element compositions; the latter record an igneous fractionation sequence that is not preserved in the former. Low equilibration temperatures indicate that major element diffusion continued long after crystallization. Diffusion coefficients for trivalent and tetravalent elements in pyroxene are lower than those of divalent elements. Therefore, major element compositions of diogenites may represent means of unknown portions of a cumulate homogenized by diffusion, while minor and trace elements still yield information on their igneous history. The scale of major element equilibration is unknown, but is likely to be on the order of a few cm. Therefore, the diogenite precursors may have consisted largely of cm-sized, igneously zoned orthopyroxene grains, which were subsequently annealed during slow cooling, obliterating major element zoning but preserving minor and trace incompatible element zoning.

Predator-prey coevolution: Australian native bees avoid their spider predators.

PubMed

Heiling, A M; Herberstein, M E

2004-05-07

Australian crab spiders Thomisus spectabilis manipulate visual flower signals to lure introduced Apis mellifera. We gave Australian native bees, Austroplebia australis, the choice between two white daisies, Chrysanthemum frutescens, one of them occupied by a crab spider. The colour contrast between flowers and spiders affected the behaviour of native bees. Native bees approached spider-occupied flowers more frequently. However, native bees avoided flowers occupied by spiders and landed on vacant flowers more frequently. In contrast to honeybees that did not coevolve with T. spectabilis, Australian native bees show an anti-predatory response to avoid flowers occupied by this predator.

Predator-prey coevolution: Australian native bees avoid their spider predators.

PubMed Central

Heiling, A M; Herberstein, M E

2004-01-01

Australian crab spiders Thomisus spectabilis manipulate visual flower signals to lure introduced Apis mellifera. We gave Australian native bees, Austroplebia australis, the choice between two white daisies, Chrysanthemum frutescens, one of them occupied by a crab spider. The colour contrast between flowers and spiders affected the behaviour of native bees. Native bees approached spider-occupied flowers more frequently. However, native bees avoided flowers occupied by spiders and landed on vacant flowers more frequently. In contrast to honeybees that did not coevolve with T. spectabilis, Australian native bees show an anti-predatory response to avoid flowers occupied by this predator. PMID:15252982

Ant mimicry lessens predation on a North American jumping spider by larger salticid spiders.

PubMed

Durkee, Caitlin A; Weiss, Martha R; Uma, Divya B

2011-10-01

Ant-like appearance (myrmecomorphy) has evolved >70 times in insects and spiders, accounting for >2,000 species of myrmecomorphic arthropods. Most myrmecomorphic spiders are considered to be Batesian mimics; that is, a palatable spider avoids predation through resemblance to an unpalatable ant-although this presumption has been tested in relatively few cases. Here we explicitly examined the extent to which Peckhamia picata (Salticidae), a North American ant-mimicking jumping spider, is protected from four species of jumping spider predators, relative to nonmimetic salticids and model ants. In addition, we conducted focused behavioral observations on one salticid predator, Thiodina puerpera, to determine the point at which the predators' behaviors toward model, mimic, and nonmimic diverge. We also examined the behaviors of Peckhamia in the presence of Thiodina. We found that mimetic jumping spiders were consumed less than a third as often as nonmimetic jumping spiders, suggesting that Peckhamia does indeed gain protection as a result of its resemblance to ants, and so can be considered a Batesian mimic. Furthermore, our focal predator did not consume any ant-mimicking spiders, and seemed to categorize Peckhamia with its model ant early in the hunting sequence. Such early determination of prey versus nonprey may be the result of speed-accuracy trade-offs in predator decision-making.

Potential health and environmental effects of trace elements and radionuclides from increased coal utilization.

PubMed Central

Van Hook, R I

1979-01-01

This report addresses the effects of coal-derived trace and radioactive elements. A summary of our current understanding of health and environmental effects of trace and radioactive elements released during coal mining, cleaning, combustion, and ash disposal is presented. Physical and biological transport phenomena which are important in determining organism exposure are also discussed. Biological concentration and transformation as well as synergistic and antagonistic actions among trace contaminants are discussed in terms of their importance in mobility, persistence, availability, and ultimate toxicity. The consequences of implementing the President's National Energy Plan are considered in terms of the impact of the NEP in 1985 and 2000 on the potential effects of trace and radioactive elements from the coal fuel cycle. Areas of needed research are identified in specific recommendations. PMID:540619

The novel approach to the biomonitor survey using one- and two-dimensional Kohonen networks.

PubMed

Deljanin, Isidora; Antanasijević, Davor; Urošević, Mira Aničić; Tomašević, Milica; Perić-Grujić, Aleksandra; Ristić, Mirjana

2015-10-01

To compare the applicability of the leaves of horse chestnut (Aesculus hippocastanum) and linden (Tilia spp.) as biomonitors of trace element concentrations, a coupled approach of one- and two-dimensional Kohonen networks was applied for the first time. The self-organizing networks (SONs) and the self-organizing maps (SOMs) were applied on the database obtained for the element accumulation (Cr, Fe, Ni, Cu, Zn, Pb, V, As, Cd) and the SOM for the Pb isotopes in the leaves for a multiyear period (2002-2006). A. hippocastanum seems to be a more appropriate biomonitor since it showed more consistent results in the analysis of trace elements and Pb isotopes. The SOM proved to be a suitable and sensitive tool for assessing differences in trace element concentrations and for the Pb isotopic composition in leaves of different species. In addition, the SON provided more clear data on seasonal and temporal accumulation of trace elements in the leaves and could be recommended complementary to the SOM analysis of trace elements in biomonitoring studies.

Multielement extraction system for the determination of 18 trace elements in geochemical samples

USGS Publications Warehouse

Clark, J.R.; Viets, J.G.

1981-01-01

A Methyl isobutyl ketone-Amine synerGistic Iodide Complex (MAGIC) extraction system has been developed for use in geochemical exploration which separates a maximum number of trace elements from interfering matrices. Extraction curves for 18 of these trace elements are presented: Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Ga, In, Tl, Sa, Pb, As, Sb, Bi, Se, and Te. The acid normality of the aqueous phase controls the extraction into the organic phase, and each of these 18 elements has a broad range of HCl normality over which H is quantitatively extracted, making H possible to determine all 18 trace elements from a single sample digestion or leach solution. The extract can be analyzed directly by flame atomic absorption or inductively coupled plasma emission spectroscopy. Most of these 18 elements can be determined by Nameless atomic absorption after special treatment of the organic extract.

Mantle End-Members: The Trace Element Perspective

NASA Astrophysics Data System (ADS)

Willbold, M.; Stracke, A.; Hofmann, A. W.

2004-12-01

On the basis of their isotopic composition, ocean island basalts (OIB) have been classified into three to four end-members; HIMU with the most radiogenic Pb isotope ratios of OIB and Enriched Mantle 1 and 2 (EM1, EM2) with less radiogenic but variable Pb isotope and highly radiogenic Sr isotope signatures. It has also been argued that each of these isotopic families has common trace element characteristics that distinguish them from one another and so substantiated this classification. Here, we present new high-precision trace element data for samples from St. Helena, Tristan da Cunha and Gough in the Atlantic Ocean. The overall data-set is augmented by OIB data from the GEOROC database and includes data from all major isotopic families (HIMU: St. Helena, Mangaia, Tubuai, and Rururtu; EM1: Tristan da Cunha, Gough, Pitcairn; and EM2: Samoa, Marquesas, and Society). For each locality we use only islands defining the most extreme isotopic compositions. The entire data-set has been screened to exclude altered and highly differentiated samples. HIMU basalts have a very uniform trace element composition. Compared to HIMU-type basalts, EM-type basalts are enriched in Rb, Ba, and K, and depleted in U, Nb, and Ta, relative to La. Different EM-type OIBs from the same isotopic family (EM1 or EM2), have distinct trace element characteristics that can ultimately only be caused by different source compositions. For example, Ba/Th ratios in samples from both Tristan da Cunha (EM1) and Samoa (EM2) are similarly high (ca. 110) whereas Ba/Th ratios in samples from Pitcairn (EM1) and Society (EM2) samples are consistently lower (ca. 70). Thus on the basis of their trace element composition, EM-type OIB cannot be classified into EM1 and EM2 type basalts, nor can any other grouping be identified. The remarkably uniform isotopic and trace element composition of HIMU-type basalts suggests derivation from a single common source reservoir, most likely subduction-modified oceanic crust. Although there are some trace element characteristics common to all EM-type basalts, which distinguish them from HIMU-type basalts (e.g. uniformly high Th/U ratios of 4.7 ± 0.3, and enrichment in Cs-U), each suite of EM-type basalts has unique trace element signatures that distinguish them from any other suite of EM-type basalts. This is especially obvious when comparing the trace element composition of EM basalts from one isotopic family, for example EM1-type basalts from Tristan, Gough and Pitcairn. Consequently, the trace element systematics of EM-type basalts suggest that there are many different EM-type sources, whereas the isotopic composition of EM-type basalts suggest derivation from two broadly similar sources, i.e. EM1 and EM2. The large variability in subducting sediments with respect to both parent-daughter (e.g. Rb/Sr, Sm/Nd, U/Pb, Th/Pb,...) and other trace element ratios makes it unlikely that there are reproducible mixtures of sediments leading to two different isotopic evolution paths (EM1 and EM2) while preserving a range of incompatible element contents for each isotopic family, as would be required to reconcile the isotopic and trace element characteristics of EM-type basalts. Although this does not a priori argue against sediments as possible source components for OIB, it does argue against two distinct groups of sediments as EM1 and EM2 sources. Further characterization of sources with the same general origin (e.g. a certain type of crust or lithosphere) or identification of processes leading to reservoirs with similar parent-daughter ratio characteristics but different incompatible trace element contents could resolve the apparent conundrum.

Factors to consider for trace element deposition biomonitoring surveys with lichen transplants

USGS Publications Warehouse

Ayrault, S.; Clochiatti, R.; Carrot, F.; Daudin, L.; Bennett, J.P.

2007-01-01

A trace element deposition biomonitoring experiment with transplants of the fruticose lichen Evernia prunastri was developed, aimed at monitoring the effects of different exposure parameters (exposure orientation and direct rain) and to the elements Ti, V, Cr, Co, Cu, Zn, Rb, Cd, Sb and Pb. Accumulations were observed for most of the elements, confirming the ability of Evernia transplants for atmospheric metal deposition monitoring. The accumulation trends were mainly affected by the exposure orientation and slightly less so by the protection from rain. The zonation of the trace elements inside the thallus was also studied. It was concluded that trace element concentrations were not homogeneous in Evernia, thus imposing some cautions on the sampling approach. A nuclear microprobe analysis of an E. prunastri transplanted thallus in thin cross-sections concluded that the trace elements were mainly concentrated on the cortex of the thallus, except Zn, Ca and K which were also present in the internal layers. The size of the particles deposited or entrapped on the cortex surface averaged 7????m. A list of key parameters to ensure the comparability of surveys aiming at observing temporal or spatial deposition variation is presented. ?? 2006 Elsevier B.V. All rights reserved.

An analysis of human exposure to trace elements from deliberate soil ingestion and associated health risks.

PubMed

Ngole-Jeme, Veronica M; Ekosse, Georges-Ive E; Songca, Sandile P

2018-01-01

Fifty-seven samples of soils commonly ingested in South Africa, Swaziland, Democratic Republic of Congo (DRC), and Togo were analyzed for the concentrations of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn) and their bioaccessibility in the human gastrointestinal tract. Bioaccessibility values were used to calculate daily intake, and hazard quotient of each trace element, and chronic hazard index (CHI) of each sample. Carcinogenic risk associated with As and Ni exposure were also calculated. Mean pseudo-total concentrations of trace elements in all samples were 7.2, 83.3, 77.1, 15.4, 28.6, 24.9, 56.1, 2.8, and 26.5 mg/kg for As, Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb, respectively. Percent bioaccessibility of Pb (13-49%) and Zn (38-56%) were highest among trace elements studied. Average daily intake values were lower than their respective reference doses for ell elements except for Pb in selected samples. Samples from DRC presented the highest health risks associated with trace element exposure with most of the samples having CHI values between 0.5 and 1.0. Some samples had higher than unacceptable values of carcinogenic risk associated with As and Ni exposure. Results indicate low trace element exposure risk from ingesting most of the soil samples.

Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements

PubMed Central

Liu, ChunMei; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Zhu, BaoNing; Li, XiuJin

2015-01-01

This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L−1·d−1 of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%–62.2% higher than with NaOH-pretreatment alone and 22.2%–56.3% higher than with untreated corn stover. The best combination was obtained 5–9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production. PMID:26137469

Trace element analysis of soil type collected from the Manjung and central Perak

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

Azman, Muhammad Azfar, E-mail: m-azfar@nuclearmalaysia.gov.my; Hamzah, Suhaimi; Rahman, Shamsiah Abdul

2015-04-29

Trace elements in soils primarily originated from their parent materials. Parents’ material is the underlying geological material that has been undergone different types of chemical weathering and leaching processes. Soil trace elements concentrations may be increases as a result of continuous input from various human activities, including power generation, agriculture, mining and manufacturing. This paper describes the Neutron Activation Analysis (NAA) method used for the determination of trace elements concentrations in part per million (ppm) present in the terrestrial environment soil in Perak. The data may indicate any contamination of trace elements contributed from human activities in the area. Themore » enrichment factors were used to check if there any contamination due to the human activities (power plants, agricultural, mining, etc.) otherwise the values would serve as a baseline data for future study. The samples were collected from 27 locations of different soil series in the area at two different depths: the top soil (0-15cm) and the sub soil (15-30cm). The collected soil samples were air dried at 60°C and passed through 2 µm sieve. Instrumental Neutron Activation Analysis (NAA) has been used for the determination of trace elements. Samples were activated in the Nuclear Malaysia TRIGA Mark II reactor followed by gamma spectrometric analysis. By activating the stable elements in the samples, the elements can be determined from the intensities of gamma energies emitted by the respected radionuclides.« less

Addition of granular activated carbon and trace elements to favor volatile fatty acid consumption during anaerobic digestion of food waste.

PubMed

Capson-Tojo, Gabriel; Moscoviz, Roman; Ruiz, Diane; Santa-Catalina, Gaëlle; Trably, Eric; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Bernet, Nicolas; Delgenès, Jean-Philippe; Escudié, Renaud

2018-07-01

The effect of supplementing granular activated carbon and trace elements on the anaerobic digestion performance of consecutive batch reactors treating food waste was investigated. The results from the first batch suggest that addition of activated carbon favored biomass acclimation, improving acetic acid consumption and enhancing methane production. Adding trace elements allowed a faster consumption of propionic acid. A second batch proved that a synergy existed when activated carbon and trace elements were supplemented simultaneously. The degradation kinetics of propionate oxidation were particularly improved, reducing significantly the batch duration and improving the average methane productivities. Addition of activated carbon favored the growth of archaea and syntrophic bacteria, suggesting that interactions between these microorganisms were enhanced. Interestingly, microbial analyses showed that hydrogenotrophic methanogens were predominant. This study shows for the first time that addition of granular activated carbon and trace elements may be a feasible solution to stabilize food waste anaerobic digestion. Copyright © 2018 Elsevier Ltd. All rights reserved.

Gull-derived trace elements trigger small-scale contamination in a remote Mediterranean nature reserve.

PubMed

Signa, Geraldina; Mazzola, Antonio; Tramati, Cecilia Doriana; Vizzini, Salvatrice

2013-09-15

The role of a yellow-legged gull (Larus michahellis) small colony in conveying trace elements (As, Cd, Cr, Cu, Ni, Pb, THg, V, Zn) was assessed in a Mediterranean nature reserve (Marinello ponds) at various spatial and temporal scales. Trace element concentrations in guano were high and seasonally variable. In contrast, contamination in the ponds was not influenced by season but showed strong spatial variability among ponds, according to the different guano input. Biogenic enrichment factor B confirmed the role of gulls in the release of trace elements through guano subsidies. In addition, comparing trace element pond concentrations to the US NOAA's SQGs, As, Cu and Ni showed contamination levels associated with possible negative biological effects. Thus, this study reflects the need to take seabirds into account as key factors influencing ecological processes and contamination levels even in remote areas, especially around the Mediterranean, where these birds are abundant but overlooked. Copyright © 2013 Elsevier Ltd. All rights reserved.

Rare earth elements minimal harvest year variation facilitates robust geographical origin discrimination: The case of PDO "Fava Santorinis".

PubMed

Drivelos, Spiros A; Danezis, Georgios P; Haroutounian, Serkos A; Georgiou, Constantinos A

2016-12-15

This study examines the trace and rare earth elemental (REE) fingerprint variations of PDO (Protected Designation of Origin) "Fava Santorinis" over three consecutive harvesting years (2011-2013). Classification of samples in harvesting years was studied by performing discriminant analysis (DA), k nearest neighbours (κ-NN), partial least squares (PLS) analysis and probabilistic neural networks (PNN) using rare earth elements and trace metals determined using ICP-MS. DA performed better than κ-NN, producing 100% discrimination using trace elements and 79% using REEs. PLS was found to be superior to PNN, achieving 99% and 90% classification for trace and REEs, respectively, while PNN achieved 96% and 71% classification for trace and REEs, respectively. The information obtained using REEs did not enhance classification, indicating that REEs vary minimally per harvesting year, providing robust geographical origin discrimination. The results show that seasonal patterns can occur in the elemental composition of "Fava Santorinis", probably reflecting seasonality of climate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Use of sediment-trace element geochemical models for the identification of local fluvial baseline concentrations

USGS Publications Warehouse

Horowitz, A.J.; Elrick, K.A.; Demas, C.R.; Demcheck, D.K.

1991-01-01

Studies have demonstrated the utility of fluvial bed sediment chemical data in assesing local water-quality conditions. However, establishing local background trace element levels can be difficult. Reference to published average concentrations or the use of dated cores are often of little use in small areas of diverse local petrology, geology, land use, or hydrology. An alternative approach entails the construction of a series of sediment-trace element predictive models based on data from environmentally diverse but unaffected areas. Predicted values could provide a measure of local background concentrations and comparison with actual measured concentrations could identify elevated trace elements and affected sites. Such a model set was developed from surface bed sediments collected nationwide in the United States. Tests of the models in a small Louisiana basin indicated that they could be used to establish local trace element background levels, but required recalibration to account for local geochemical conditions outside the range of samples used to generate the nationwide models.

Genome-Wide RNAi Ionomics Screen Reveals New Genes and Regulation of Human Trace Element Metabolism

PubMed Central

Malinouski, Mikalai; Hasan, Nesrin M.; Zhang, Yan; Seravalli, Javier; Lin, Jie; Avanesov, Andrei; Lutsenko, Svetlana; Gladyshev, Vadim N.

2017-01-01

Trace elements are essential for human metabolism and dysregulation of their homeostasis is associated with numerous disorders. Here we characterize mechanisms that regulate trace elements in human cells by designing and performing a genome-wide high-throughput siRNA/ionomics screen, and examining top hits in cellular and biochemical assays. The screen reveals high stability of the ionomes, especially the zinc ionome, and yields known regulators and novel candidates. We further uncover fundamental differences in the regulation of different trace elements. Specifically, selenium levels are controlled through the selenocysteine machinery and expression of abundant selenoproteins; copper balance is affected by lipid metabolism and requires machinery involved in protein trafficking and posttranslational modifications; and the iron levels are influenced by iron import and expression of the iron/heme-containing enzymes. Our approach can be applied to a variety of disease models and/or nutritional conditions, and the generated dataset opens new directions for studies of human trace element metabolism. PMID:24522796

Topical index and bibliography of U.S. Geological Survey Trace Elements and related reports

USGS Publications Warehouse

Curtis, Diane; Houser, Shirley S.

1952-01-01

Part 1, the topical index, lists the titles of reports prepared from 1941 to December 1952, in conjunction with the Geological Survey's program of uranium and other elements of related interest. It includes not only completed Trace Elements reports and those now in preparation, but also Survey publications, publications by Survey personnel in scientific journals, and open-fie releases. The titles are grouped topically under the headings listed in the table of contents. Entries in each category are listed alphabetically, by author, and numbered consecutively. Many of the reports have been cross-indexed, where appropriate. The classification of the Trace Elements reports, insofar as it is known, has been indicated after the title of the report. The classification of some of the earlier Trace Elements reports is uncertain. The Geological Survey does not have additional copies of most of the reports listed, but copies of some of the completed reports can be loaned on request to organizations officially cooperating with the Atomic Energy Commission. Many Trace Elements reports have been made available to the public, either by open-file release, reproduction by Technical Information Service, Oak Ridge (referred to as TIS), by publication as a Geological Survey circular or bulletin or by a publication in a scientific journal. This information is given, following the title of the report. If the abstract of a Trace Element report has been published in Nuclear Science Abstracts, it is noted by the initials NSA following the title of the report. Part 2 is a reference guide to information on the Trace Elements program that is available to the public. This information is categorized according to the type of publication or release.

Contributions of trace elements to the sea by small uncontaminated rivers: Effects of a water reservoir and a wastewater treatment plant.

PubMed

Álvarez-Vázquez, Miguel Ángel; Prego, Ricardo; Caetano, Miguel; De Uña-Álvarez, Elena; Doval, Maryló; Calvo, Susana; Vale, Carlos

2017-07-01

Trace element contributions from small rivers to estuaries is an issue barely addressed in the literature. In this work, freshwater flowing into the Ria of Cedeira (NW Iberian Peninsula) was studied during a hydrological year through the input from three rivers, one considered uncontaminated (the Das-Mestas River), a second affected by urban treated wastewater discharges (the Condomiñas River), and the third containing a water reservoir for urban supply (the Forcadas River). With the objective of assessing the possible influence of human pressure, the annual yields for selected trace elements (Al, Fe, As, Cd, Co, Cr, Cu, Mn, Mo, Ni and Pb) were estimated and compared by normalizing by basin surface. Both dissolved and particulate transported elements were considered. After the data treatment and analysis it can be highlighted that: (i) the Das Mestas River is suitable to be included between the short European pristine baseline of small rivers, at least regarding the transported trace elements; (ii) natural enrichments were identified associated to the lithology of the basin in the Das-Mestas River (i.e. As) and in the Condomiñas River (i.e. Co, Cr and Ni); this fact highlights the importance of considering the local background for a proper assessment; (iii) the impoundment in the Forcadas River is related with a general decrease, even depletion, of the particulate and dissolved transported trace elements, except Mn; (iv) the discharge of sewage to the Condomiñas River is increasing the inputs to the ria of some trace elements in the particulate phase (i.e. Al, Cu and Pb). Both observed human-induced changes can be regarded as typical disturbances of trace element contributions from small rivers to estuaries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sampling strategy and analysis of trace element concentrations by inductively coupled plasma mass spectrometry on medieval human bones--the concept of chemical life history.

PubMed

Skytte, Lilian; Rasmussen, Kaare Lund

2013-07-30

Medieval human bones have the potential to reveal diet, mobility and treatment of diseases in the past. During the last two decades trace element chemistry has been used extensively in archaeometric investigations revealing such data. Many studies have reported the trace element inventory in only one sample from each skeleton - usually from the femur or a tooth. It cannot a priori be assumed that all bones or teeth in a skeleton will have the same trace element concentrations. Six different bone and teeth samples from each individual were carefully decontaminated by mechanical means. Following dissolution of ca. 20 mg sample in nitric acid and hydrogen peroxide the assays were performed using inductively coupled plasma mass spectrometry (ICPMS) with quadropole detection. We describe the precise sampling technique as well as the analytical methods and parameters used for the ICPMS analysis. The places of sampling in the human skeleton did exhibit varying trace element concentrations. Although the samples are contaminated by Fe, Mn and Al from the surrounding soil where the bones have been residing for more than 500 years, other trace elements are intact within the bones. It is shown that the elemental ratios Sr/Ca and Ba/Ca can be used as indicators of provenance. The differences in trace element concentrations can be interpreted as indications of varying diet and provenance as a function of time in the life of the individual - a concept which can be termed chemical life history. A few examples of the results of such analyses are shown, which contains information about provenance and diagenesis. Copyright © 2013 John Wiley & Sons, Ltd.

Invited review current progress and limitations of spider silk for biomedical applications.

PubMed

Widhe, Mona; Johansson, Jan; Hedhammar, My; Rising, Anna

2012-06-01

Spider silk is a fascinating material combining remarkable mechanical properties with low density and biodegradability. Because of these properties and historical descriptions of medical applications, spider silk has been proposed to be the ideal biomaterial. However, overcoming the obstacles to produce spider silk in sufficient quantities and in a manner that meets regulatory demands has proven to be a difficult task. Also, there are relatively few studies of spider silk in biomedical applications available, and the methods and materials used vary a lot. Herein we summarize cell culture- and in vivo implantation studies of natural and synthetic spider silk, and also review the current status and future challenges in the quest for a large scale production of spider silk for medical applications. Copyright © 2011 Wiley Periodicals, Inc.

Marine chemistry of the permian phosphoria formation and basin, Southeast Idaho

USGS Publications Warehouse

Piper, D.Z.

2001-01-01

Major components in the Meade Peak Member of the Phosphoria Formation are apatite, dolomite, calcite, organic matter, and biogenic silica-a marine fraction; and aluminosilicate quartz debris-a terrigenous fraction. Samples from Enoch Valley, in southeast Idaho, have major element oxide abundances of Al2O3, Fe2O3, K2O, and TiO2 that closely approach the composition of the world shale average. Factor analysis further identifies the partitioning of several trace elements-Ba, Ga, Li, Sc, and Th and, at other sites in southeast Idaho and western Wyoming, B, Co, Cs, Hf, Rb, and Ta-totally into this fraction. Trace elements that fail to show such correlations or factor loadings include Ag, As, Cd, Cr, Cu, Mo, Ni, Se, the rare earth elements (REE), U, V, and Zn. Their terrigenous contribution is determined from minimum values of trace elements versus the terrigenous fraction. These minima too define trace element concentrations in the terrigenous fraction that approximately equal their concentrations in the world shale average. The marine fraction of trace elements represents the difference between the bulk trace element content of a sample and the terrigenous contribution. Of the trace elements enriched above a terrigenous contribution, Ag, Cr, Cu, Mo, and Se show strong loadings on the factor with an organic matter loading and U and the REE on the factor with a strong apatite loading. Cd, Ni, V, and Zn do not show a strong correlation with any of the marine components but are, nonetheless, strongly enriched above a terrigenous contribution. Interelement relationships between the trace elements identify two seawater sources-planktonic debris and basinal bottom water. Relationships between Cd, Cu, Mo, Zn, and possibly Ni and Se suggest a solely biogenic source. Their accumulation rates, and that of PO3-4, further identify the level of primary productivity as having been moderate and the residence time of water in the basin at 4.5 yr. Enrichments of Cr, U, V, and the REE, above both terrigenous and biogenic contributions, define bottom-water redox conditions as having been oxygen depleted, that is, denitrifying but not sulfate reducing.

New Developments in Hard X-ray Fluorescence Microscopy for In-situ Investigations of Trace Element Distributions in Aqueous Systems of Soil Colloids

NASA Astrophysics Data System (ADS)

Gleber, Sophie-Charlotte; Weinhausen, Britta; Köster, Sarah; Ward, Jesse; Vine, David; Finney, Lydia; Vogt, Stefan

2013-10-01

The distribution, binding and release of trace elements on soil colloids determine matter transport through the soil matrix, and necessitates an aqueous environment and short length and time scales for their study. However, not many microscopy techniques allow for that. We previously showed hard x-ray fluorescence microscopy capabilities to image aqueous colloidal soil samples [1]. As this technique provides attogram sensitivity for transition elements like Cu, Zn, and other geochemically relevant trace elements at sub micrometer spatial resolution (currently down to 150 nm at 2-ID-E [2]; below 50nm at Bionanoprobe, cf. G.Woloschak et al, this volume) combined with the capability to penetrate tens of micrometer of water, it is ideally suited for imaging the elemental content of soil colloids. To address the question of binding and release processes of trace elements on the surface of soil colloids, we developed a microfluidics based XRF flow cytometer, and expanded the applied methods of hard x-ray fluorescence microscopy towards three dimensional imaging. Here, we show (a) the 2-D imaged distributions of Si, K and Fe on soil colloids of Pseudogley samples; (b) how the trace element distribution is a dynamic, pH-dependent process; and (c) x-ray tomographic applications to render the trace elemental distributions in 3-D. We conclude that the approach presented here shows the remarkable potential to image and quantitate elemental distributions from samles within their natural aqueous microenvironment, particularly important in the environmental, medical, and biological sciences.

Induction of direct and indirect plant responses by jasmonic acid, low spider mite densities, or a combination of jasmonic acid treatment and spider mite infestation.

PubMed

Gols, Rieta; Roosjen, Mara; Dijkman, Herman; Dicke, Marcel

2003-12-01

Jasmonic acid (JA) and the octadecanoid pathway are involved in both induced direct and induced indirect plant responses. In this study, the herbivorous mite, Tetranychus urticae, and its predator, Phytoseiulus persimilis, were given a choice between Lima bean plants induced by JA or spider mites and uninduced control plants. Infestation densities resulting in the induction of predator attractants were much lower than thus far assumed, i.e., predatory mites were significantly attracted to plants that were infested for 2 days with only one or four spider mites per plant. Phytoseiulus persimilis showed a density-dependent response to volatiles from plants that were infested with different numbers of spider mites. Similarly, treating plants with increasing concentrations of JA also led to increased attraction of P. persimilis. Moreover, the duration of spider mite infestation was positively correlated with the proportion of predators that were attracted to mite-infested plants. A pretreatment of the plants with JA followed by a spider mite infestation enhanced the attraction of P. persimilis to plant volatiles compared to attraction to volatiles from plants that were only infested with spider mites and did not receive a pretreatment with JA. The herbivore, T. urticae preferred leaf tissue that previously had been infested with conspecifics to uninfested leaf tissue. In the case of choice tests with JA-induced and control leaf tissue, spider mites slightly preferred control leaf tissue. When spider mites were given a choice between leaf discs induced by JA and leaf discs damaged by spider mite feeding, they preferred the latter. The presence of herbivore induced chemicals and/or spider mite products enhanced settlement of the mites, whereas treatment with JA seemed to impede settlement.

Impacts of spinosad and λ-cyhalothrin on spider communities in cabbage fields in south Texas.

PubMed

Liu, T-X; Irungu, R W; Dean, D A; Harris, M K

2013-04-01

Spiders are a principal arthropod group that preys on numerous pests of vegetables and other crops. In this study, we determined the effects of the two most commonly used insecticides, spinosad and λ-cyhalothrin, on diversity of spiders on cabbage in south Texas. In two seasons (fall 2008 and spring 2009), we collected a total of 588 spiders belonging to 53 species in 11 families from spinosad and λ-cyhalothrin-treated cabbages and the untreated control plants. A great majority of spiders were collected from the pitfall traps (554) where only a few (34) were collected from the blower/vacuum sampling. In the insecticide-treated plots, there were significantly fewer spider individuals, species and families than in untreated fields. Spinosad had significantly less effect on spiders in total individuals, number of species and families than λ-cyhalothrin. The effects of the two insecticides were further demonstrated by the Shannon-Weiner index (H') and the hierarchical richness index (HRI). Spider diversity in the spinosad-treated plots were not significantly different from that in the untreated fields but were greater than those in λ-cyhalothrin-treated plots in both seasons when measured by H' values. In contrast, the H' values of spider's diversity in the λ-cyhalothrin-treated plots were significantly lower than spinosad-treated and untreated plots. High values of HRI for spider richness in the spinosad-treated plots suggested that spinosad had less effect on spiders than λ-cyhalothrin. We concluded that spinosad was more compatible with spiders on cabbage compared to λ-cyhalothrin and that this information should be used when developing insecticide resistance management strategies.

Linking Vegetation Structure and Spider Diversity in Riparian and Adjacent Habitats in Two Rivers of Central Argentina: An Analysis at Two Conceptual Levels.

PubMed

Griotti, Mariana; Muñoz-Escobar, Christian; Ferretti, Nelson E

2017-08-01

The link between vegetation structure and spider diversity has been well explored in the literature. However, few studies have compared spider diversity and its response to vegetation at two conceptual levels: assemblage (species diversity) and ensemble (guild diversity). Because of this, we studied spider diversity in riparian and adjacent habitats of a river system from the Chacoan subregion in central Argentina and evaluated their linkage with vegetation structure at these two levels. To assess vegetation structure, we measured plant species richness and vegetation cover in the herb and shrub - tree layers. We collected spiders for over 6 months by using vacuum netting, sweep netting and pitfall traps. We collected 3,808 spiders belonging to 119 morphospecies, 24 families and 9 guilds. At spider assemblage level, SIMPROF analysis showed significant differences among studied habitats. At spider ensemble level, nevertheless, we found no significant differences among habitats. Concerning the linkage with vegetation structure, BIOENV test showed that spider diversity at either assemblage or ensemble level was not significantly correlated with the vegetation variables assessed. Our results indicated that spider diversity was not affected by vegetation structure. Hence, even though we found a pattern in spider assemblages among habitats, this could not be attributed to vegetation structure. In this study, we show that analyzing a community at two conceptual levels will be useful for recognizing different responses of spider communities to vegetation structure in diverse habitat types. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Trace Elements in Bed Sediments and Biota from Streams in the Santee River Basin and Coastal Drainages, North and South Carolina, 1995-97

Treesearch

Thomas A. Abrahamsen

1999-01-01

Bed-sediment and tissue samples were collected and analyzed for the presence of trace elements from 25 sites in the Santee River Basin and coastal drainages study area during 1995-97 as part of the U.S. Geological Survey's National Water-Quality Assessment Program, Sediment trace-element priority-pollutant concentrations were compared among streams draining water-...

Evaluating Crustal Contamination Effects On The Lithophile Trace Element Budget Of Shergottites, NWA 856 As A Test Case

NASA Technical Reports Server (NTRS)

Brandon, A. D.; Ferdous, J.; Peslier, A. H.

2017-01-01

The issue of whether crustal contamination has affected the lithophile trace element budget of shergottites has been a point of contention for decades. The evaluation has focused on the enriched shergottite compositions as an outcome of crustal contamination of mantle-derived parent magmas or, alternatively, the compositions of these stones reflect an incompatible trace element (ITE) enriched mantle source.

Movement of Trace Elements During Residence in the Antarctic Ice: a Laboratory Simulation

NASA Technical Reports Server (NTRS)

Strait, Melissa M.

1991-01-01

Recent work has determined that differences in the trace element distribution between Antarctic eucrites and non-Antarctic eucrites may be due to weathering during residence in the ice, and samples that demonstrate trace element disturbances do not necessarily correspond to eucrites that appear badly weathered to the naked eye. This study constitutes a preliminary test of the idea that long-term residence in the ice is the cause of the trace element disturbances observed in the eucrites. Samples of a non-Antarctic eucrite were leached in water at room temperature conditions. Liquid samples were analyzed for rare earth element abundances using ion chromatography. The results for the short-term study showed little or no evidence that leaching had occurred. However, there were tantalizing hints that something may be happening. The residual solid samples are currently being analyzed for the unleached trace metals using instrumental neutron activation analysis and should show evidence of disturbance if the chromatography clues were real. In addition, another set of samples continues to be intermittently sampled for later analysis. The results should give us information about the movement of trace elements under our conditions and allow us to make some tentative extrapolations to what we observe in actual Antarctic eucrite samples.

Application of major and trace elements as well as boron isotopes for tracing hydrochemical processes: the case of Trifilia coastal karst aquifer, Greece

NASA Astrophysics Data System (ADS)

Panagopoulos, G.

2009-09-01

The Trifilia karst aquifer presents a complex hydrochemical character due to the intricate geochemical processes that take place in the area. Their discernment was achieved by using the chemical analyses of major, trace elements and boron isotopes. Major ion composition indicates mixing between seawater and freshwater is occurring. Five hydrochemical zones corresponding to five respective groundwater types were distinguished, in which the chemical composition of groundwater is influenced mainly due to the different salinization grade of the aquifer. The relatively increased temperature of the aquifer indicates the presence of hydrothermal waters. Boron isotopes and trace elements indicate that the intruding seawater has been hydrothermally altered, as it is shown by the δ11B depleted signature and the increased concentrations of Li and Sr. Trace elements analyses showed that the groundwater is enriched in various metallic elements, which derive from the solid hydrocarbons (bitumens), contained in the carbonate sediments of the Tripolis zone. The concentration of these trace elements depends on the redox environment. Thus, in reductive conditions As, Mn, Co and NH4 concentrations are high, in oxidized conditions the V, Se, Mo, Tl and U concentration increases while Ni is not redox sensitive and present high concentration in both environments.

Essential trace elements and antioxidant status in relation to severity of HIV in Nigerian patients.

PubMed

Olaniyi, J A; Arinola, O G

2007-01-01

This study was designed to determine the plasma levels of some antioxidants and trace elements in three severity groups of HIV patients compared with non-HIV-infected controls. The plasma levels of antioxidants (total antioxidant, albumin, bilirubin and uric acid) and trace elements (Mg, Fe, Zn, Mn, Cu, Cr, Cd and Se) were estimated spectrophotometrically in controls and patients with CD4 counts of <200; 200-499 and > or =500 cells/microl. Uric acid and Zn were significantly higher, while vitamin E and all the trace elements (except Zn) were significantly lower in HIV-infected patients compared to healthy controls. The highest level of uric acid was observed in those with CD4 counts of <200 cells/microl. All the trace elements (except Zn) were higher in HIV subjects with a CD4 count of 200-499 cells/microl compared to >500 cells/microl. Only uric acid and Zn showed significant correlation with CD4 count. Based on the results of this study, we recommend routine assessment and appropriate supplementation of antioxidants/trace elements in HIV subjects. This supplementation is hoped to strengthen the immune system and reduce the adverse consequences of HIV- related oxidative stress. Copyright 2007 S. Karger AG, Basel.

Using lead isotopes and trace element records from two contrasting Lake Tanganyika sediment cores to assess watershed – Lake exchange

USGS Publications Warehouse

Odigie, Kingsley; Cohen, A.D.; Swarzenski, Peter W.; Flegal, R

2014-01-01

Lead isotopic and trace element records of two contrasting sediment cores were examined to reconstruct historic, industrial contaminant inputs to Lake Tanganyika, Africa. Observed fluxes of Co, Cu, Mn, Ni, Pb, and Zn in age-dated sediments collected from the lake varied both spatially and temporally over the past two to four centuries. The fluxes of trace elements were lower (up to 10-fold) at a mid-lake site (MC1) than at a nearshore site (LT-98-58), which is directly downstream from the Kahama and Nyasanga River watersheds and adjacent to the relatively pristine Gombe Stream National Park. Trace element fluxes at that nearshore site did not measurably change over the last two centuries (1815–1998), while the distal, mid-lake site exhibited substantial changes in the fluxes of trace elements – likely caused by changes in land use – over that period. For example, the flux of Pb increased by ∼300% from 1871 to 1991. That apparent accelerated weathering and detrital mobilization of lithogenic trace elements was further evidenced by (i) positive correlations (r = 0.77–0.99, p < 0.05) between the fluxes of Co, Cu, Mn, Ni, Pb, and Zn and those of iron (Fe) at both sites, (ii) positive correlations (r = 0.82–0.98, p < 0.01, n = 9) between the fluxes of elements (Al, Co, Cu, Fe, Mn, Ni, Pb, and Zn) and the mass accumulation rates at the offshore site, (iii) the low enrichment factors (EF < 5) of those trace elements, and (iv) the temporal consistencies of the isotopic composition of Pb in the sediment. These measurements indicate that accelerated weathering, rather than industrialization, accounts for most of the increases in trace element fluxes to Lake Tanganyika in spite of the development of mining and smelting operations within the lake’s watershed over the past century. The data also indicate that the mid-lake site is a much more sensitive and useful recorder of environmental changes than the nearshore site. Furthermore, the lead isotopic compositions of sediment at the sites differed spatially, indicating that the Pb (and other trace elements by association) originated from different natural sources at the two locations.

Trace element abundance determinations by Synchrotron X Ray Fluorescence (SXRF) on returned comet nucleus mineral grains

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Sutton, S. R.

1989-01-01

Trace element analyses were performed on bulk cosmic dust particles by Proton Induced X Ray Emission (PIXE) and Synchrotron X Ray Fluorescence (SXRF). When present at or near chondritic abundances the trace elements K, Ti, Cr, Mn, Cu, Zn, Ga, Ge, Se, and Br are presently detectable by SXRF in particles of 20 micron diameter. Improvements to the SXRF analysis facility at the National Synchrotron Light Source presently underway should increase the range of detectable elements and permit the analysis of smaller samples. In addition the Advanced Photon Source will be commissioned at Argonne National Laboratory in 1995. This 7 to 8 GeV positron storage ring, specifically designed for high-energy undulator and wiggler insertion devices, will be an ideal source for an x ray microprobe with one micron spatial resolution and better than 100 ppb elemental sensitivity for most elements. Thus trace element analysis of individual micron-sized grains should be possible by the time of the comet nucleus sample return mission.

The impact of lifestyle factors on age-related differences in hair trace element content in pregnant women in the third trimester.

PubMed

Skalny, Anatoly V; Tinkov, Alexey A; Voronina, Irina; Terekhina, Olga; Skalnaya, Margarita G; Bohan, Tatiana G; Agarkova, Lyubov A; Kovas, Yulia

2018-01-01

Trace elements play a significant role in the regulation of human reproduction, while advanced age may have a significant impact on trace element metabolism. The objective of the present study was to assess the impact of lifestyle factors on age-related differences in hair trace element content in pregnant women in the third trimester. A total of 124 pregnant women aged 20–29 (n = 72) and 30–39 (n = 52) were ex- amined. Scalp hair trace element content was assessed using inductively coupled plasma mass spectrometry at NexION 300D (Perkin Elmer, USA) after microwave digestion. The results showed that the elder pregnant women had 36% (p = 0.009), 14% (p = 0.045), and 45% (p = 0.044) lower hair Zn, V, and Cd content, and 16% (p = 0.044) higher hair B levels – in comparison to the respective younger group values. Multiple regression analysis demonstrated that the age of the women had a significant influence on hair V and Zn levels. B content was also significantly influenced by age at first intercourse, smoking status, and specific dietary habits. None of the lifestyle factors were associated with hair Cd content in pregnant women. Hair V levels were also affected by following a special diet. Interestingly, alcohol intake did not have a significant impact on hair trace element content. These data indicate that lifestyle factors have a significant influence on age-related changes in hair trace elements during pregnancy that may impact the outcome of pregnancy.

Mapping Fifteen Trace Elements in Human Seminal Plasma and Sperm DNA.

PubMed

Ali, Sazan; Chaspoul, Florence; Anderson, Loundou; Bergé-Lefranc, David; Achard, Vincent; Perrin, Jeanne; Gallice, Philippe; Guichaoua, Marie

2017-02-01

Studies suggest a relationship between semen quality and the concentration of trace elements in serum or seminal plasma. However, trace elements may be linked to DNA and capable of altering the gene expression patterns. Thus, trace element interactions with DNA may contribute to the mechanisms for a trans-generational reproductive effect. We developed an analytical method to determine the amount of trace elements bound to the sperm DNA, and to estimate their affinity for the sperm DNA by the ratio: R = Log [metal concentration in the sperm DNA/metal concentration in seminal plasma]. We then analyzed the concentrations of 15 trace elements (Al, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Ti, V, Zn, As, Sb, and Se) in the seminal plasma and the sperm DNA in 64 normal and 30 abnormal semen specimens with Inductively Coupled Plasma/Mass Spectrometry (ICP-MS). This study showed all trace elements were detected in the seminal plasma and only metals were detected in the sperm DNA. There was no correlation between the metals' concentrations in the seminal plasma and the sperm DNA. Al had the highest affinity for DNA followed by Pb and Cd. This strong affinity is consistent with the known mutagenic effects of these metals. The lowest affinity was observed for Zn and Ti. We observed a significant increase of Al linked to the sperm DNA of patients with oligozoospermia and teratozoospermia. Al's reproductive toxicity might be due to Al linked to DNA, by altering spermatogenesis and expression patterns of genes involved in the function of reproduction.

Enhanced analgesic effects of tramadol and common trace element coadministration in mice.

PubMed

Alexa, Teodora; Marza, Aurelia; Voloseniuc, Tudor; Tamba, Bogdan

2015-10-01

Chronic pain is managed mostly by the daily administration of analgesics. Tramadol is one of the most commonly used drugs, marketed in combination with coanalgesics for enhanced effect. Trace elements are frequent ingredients in dietary supplements and may enhance tramadol's analgesic effect either through synergic mechanisms or through analgesic effects of their own. Swiss Weber male mice were divided into nine groups and were treated with a combination of the trace elements Mg, Mn, and Zn in three different doses and a fixed dose of tramadol. Two groups served as positive (tramadol alone) and negative (saline) controls. Nociceptive assessment by tail-flick (TF) and hot-plate (HP) tests was performed at baseline and at 15, 30, 45, and 60 min after intraperitoneal administration. Response latencies were recorded and compared with the aid of ANOVA testing. All three trace elements enhanced tramadol's analgesic effect, as assessed by TF and HP test latencies. Coadministration of these trace elements led to an increase of approximately 30% in the average pain inhibition compared with the tramadol-alone group. The most effective doses were 0.6 mg/kg b.w. for Zn, 75 mg/kg b.w. for Mg, and 7.2 mg/kg b.w. for Mn. Associating trace elements such as Zn, Mg, and Mn with the standard administration of tramadol increases the drug's analgesic effect, most likely a consequence of their synergic action. These findings impact current analgesic treatment because the addition of these trace elements may reduce the tramadol dose required to obtain analgesia. © 2015 Wiley Periodicals, Inc.

Trace elements record complex histories in diogenites

NASA Astrophysics Data System (ADS)

Balta, J. B.; Beck, A. W.; McSween, H. Y.

2012-12-01

Diogenite meteorites are cumulate rocks composed mostly of orthopyroxene and chemically linked to eucrites (basaltic) and howardites (brecciated mixtures of diogenites and eucrites). Together, they represent the largest single family of achondrite meteorites delivered to Earth, and have been spectrally linked to the asteroid 4 Vesta, the largest remaining basaltic protoplanet. However, this spectral link is non-unique as many basaltic asteroids likely formed and were destroyed in the early solar system. Recent work suggested that Vesta may be an unlikely parent body for the diogenites based on correlations between trace elements and short-lived isotope decay products, which would be unlikely to survive on a body as large as Vesta due to its long cooling history [1]. Recent analyses of terrestrial and martian olivines have demonstrated that trace element spatial distributions can preserve evidence of their crystallization history even when major elements have been homogenized [2]. We have mapped minor elements including Cr, Al, and Ti in seemingly homogeneous diogenite orthopyroxenes and found a variety of previously unobserved textures. The pyroxenes in one sample (GRA 98108) are seemingly large grains of variable shapes and sizes, but the trace elements reveal internal grain boundaries between roughly-equal sized original subgrains, with equilibrated metamorphic triple junctions between them and trace element depletions at the boundaries. These trends suggest extraction of trace elements by a magma along those relict grain boundaries during a reheating event. Two other samples show evidence of fracturing and annealing, with trace element mobility within grains. One sample appears to have remained a closed system during annealing (MET 01084), while the other has interacted with a fluid or magma to move elements along annealed cracks (LEW 88679). These relict features establish that the history of diogenite pyroxenes is more complex than their homogeneous major element compositions imply. Many trace element analyses are performed using either bulk rock techniques or spot analyses, and these maps suggest those types of analyses likely sample variable trace element abundances even within otherwise homogeneous grains, rendering their results difficult to interpret. Consequently, the correlation discussed previously between trace elements and short lived isotopes has likely been impacted by post-magmatic alteration and cannot solely be used to argue that HED's cannot be derived from Vesta. Furthermore, these maps strengthen the HED-Vesta link by suggesting that the diogenites underwent an extended history of cooling, reheating, partial melting, impact fragmentation, fluid/melt migration, and finally re-annealing. These complicated steps are particularly noteworthy as the pyroxene cumulate layer on the asteroid Vesta should lie beneath the eucritic crust, implying that early impacts were able to penetrate that crust and affect the diogenite layers early in Vesta's history, most likely while the asteroid was still hot enough to allow for annealing and regrowth of fractured grains. [1] Schiller et al. (2011) [2] Milman-Barris et al. (2008)

Loss of legs: is it or not a handicap for an orb-weaving spider?

NASA Astrophysics Data System (ADS)

Pasquet, Alain; Anotaux, Mylène; Leborgne, Raymond

2011-07-01

Leg loss is a common phenomenon in spiders, and according to the species 5% to 40% of the adults can present at least one missing leg. There is no possibility of regeneration after adult moult and the animal must manage with its missing appendages until its death. With the loss of one or more legs, female orb-weaving spiders can be penalized twice: firstly, because the legs are necessary for web construction and secondly, the legs are essential for the control of the prey after its interception by the web. During development, spiders may be also penalized because regeneration has energetic costs that take away resources for survival, growth and reproduction. All these consequences should influence negatively the development of the spider and thus its fitness. We investigated the impact of leg loss in the orb-weaving spider, Zygiella x-notata by studying its frequency in a natural population and web building and prey capture behaviours in laboratory. In field populations, 9.5% to 13%, of the adult females presented the loss of one or more legs; the majority of individuals had lost only one leg (in 48% of cases, a first one). Leg loss seems to affect all the adult spiders, as there is no difference of mass between intact spiders and those with missing leg. Data obtained with laboratory-reared spiders, showed that the loss of legs due to the moult is rare (less than 1%). Considering changes in web design, spiders with missing legs decreased their silk investment, increased the distance between spiral turns but did not change the capture surface of the web. Under our laboratory experimental conditions, spiders with one or two lost legs did not present any difference in prey capture efficiency. In laboratory conditions, spiders with lost leg(s) did not show any difference in egg sac production or in longevity (adult lifespan) compared to intact spiders.

Spiders spinning electrically charged nano-fibres

PubMed Central

Kronenberger, Katrin; Vollrath, Fritz

2015-01-01

Most spider threads are on the micrometre and sub-micrometre scale. Yet, there are some spiders that spin true nano-scale fibres such as the cribellate orb spider, Uloborus plumipes. Here, we analyse the highly specialized capture silk-spinning system of this spider and compare it with the silk extrusion systems of the more standard spider dragline threads. The cribellar silk extrusion system consists of tiny, morphologically basic glands each terminating through exceptionally long and narrow ducts in uniquely shaped silk outlets. Depending on spider size, hundreds to thousands of these outlet spigots cover the cribellum, a phylogenetically ancient spinning plate. We present details on the unique functional design of the cribellate gland–duct–spigot system and discuss design requirements for its specialist fibrils. The spinning of fibres on the nano-scale seems to have been facilitated by the evolution of a highly specialist way of direct spinning, which differs from the aqua-melt silk extrusion set-up more typical for other spiders. PMID:25631231

Uncovering the structure-function relationship in spider silk

NASA Astrophysics Data System (ADS)

Yarger, Jeffery L.; Cherry, Brian R.; van der Vaart, Arjan

2018-03-01

All spiders produce protein-based biopolymer fibres that we call silk. The most studied of these silks is spider dragline silk, which is very tough and relatively abundant compared with other types of spider silks. Considerable research has been devoted to understanding the relationship between the molecular structure and mechanical properties of spider dragline silks. In this Review, we overview experimental and computational studies that have provided a wealth of detail at the molecular level on the highly conserved repetitive core and terminal regions of spider dragline silk. We also discuss the role of the nanocrystalline β-sheets and amorphous regions in determining the properties of spider silk fibres, endowing them with strength and elasticity. Additionally, we outline imaging techniques and modelling studies that elucidate the importance of the hierarchical structure of silk fibres at the molecular level. These insights into structure-function relationships can guide the reverse engineering of spider silk to enable the production of superior synthetic fibres.

Interpretative bias in spider phobia: Perception and information processing of ambiguous schematic stimuli.

PubMed

Haberkamp, Anke; Schmidt, Filipp

2015-09-01

This study investigates the interpretative bias in spider phobia with respect to rapid visuomotor processing. We compared perception, evaluation, and visuomotor processing of ambiguous schematic stimuli between spider-fearful and control participants. Stimuli were produced by gradually morphing schematic flowers into spiders. Participants rated these stimuli related to their perceptual appearance and to their feelings of valence, disgust, and arousal. Also, they responded to the same stimuli within a response priming paradigm that measures rapid motor activation. Spider-fearful individuals showed an interpretative bias (i.e., ambiguous stimuli were perceived as more similar to spiders) and rated spider-like stimuli as more unpleasant, disgusting, and arousing. However, we observed no differences between spider-fearful and control participants in priming effects for ambiguous stimuli. For non-ambiguous stimuli, we observed a similar enhancement for phobic pictures as has been reported previously for natural images. We discuss our findings with respect to the visual representation of morphed stimuli and to perceptual learning processes. Copyright © 2015 Elsevier B.V. All rights reserved.

Spiders spinning electrically charged nano-fibres.

PubMed

Kronenberger, Katrin; Vollrath, Fritz

2015-01-01

Most spider threads are on the micrometre and sub-micrometre scale. Yet, there are some spiders that spin true nano-scale fibres such as the cribellate orb spider, Uloborus plumipes. Here, we analyse the highly specialized capture silk-spinning system of this spider and compare it with the silk extrusion systems of the more standard spider dragline threads. The cribellar silk extrusion system consists of tiny, morphologically basic glands each terminating through exceptionally long and narrow ducts in uniquely shaped silk outlets. Depending on spider size, hundreds to thousands of these outlet spigots cover the cribellum, a phylogenetically ancient spinning plate. We present details on the unique functional design of the cribellate gland-duct-spigot system and discuss design requirements for its specialist fibrils. The spinning of fibres on the nano-scale seems to have been facilitated by the evolution of a highly specialist way of direct spinning, which differs from the aqua-melt silk extrusion set-up more typical for other spiders. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

De novo design of recombinant spider silk proteins for material applications.

PubMed

Zheng, Ke; Ling, Shengjie

2018-05-21

Spider silks are well known for their superior mechanical properties that are stronger and tougher than steel despite being assembled at close to ambient conditions and using water as the solvent. However, it is a significant challenge to utilize spider silks for practical applications due to their limited sources. Fortunately, genetic engineering techniques offer a promising approach to produce useable amounts of spider silk variants. Starting from these recombinant spider silk proteins, a series of experiments and simulations strategies were developed to improve the recombinant spider silk proteins (RSSP) material design and fabrication with the aim of biomimicking the structure-property-function relationships of spider silks. Accordingly, in this review, we first introduce the structure-property-function relationship of spider silks. Then, we discuss the recent progress in the genetic synthesis of RSSPs and summarize their related multiscale self-assembly behaviors. Finally, we outline works utilizing multiscale modeling to assist RSSP material design. This article is protected by copyright. All rights reserved.

Mermithid parasitism of Hawaiian Tetragnatha spiders in a fragmented landscape

USGS Publications Warehouse

Vandergast, Amy; Roderick, George K.

2003-01-01

Hawaiian Tetragnatha spiders inhabiting small forest fragments on the Big Island of Hawaii are parasitized by mermithid nematodes. This is the first report of mermithid nematodes infecting spiders in Hawaii, and an initial attempt to characterize this host–parasite interaction. Because immature mermithids were not morphologically identifiable, a molecular identification was performed. A phylogenetic analysis based on 18S small ribosomal subunit nuclear gene sequences suggested that Hawaiian spider mermithids are more closely related to a mainland presumptive Aranimemis species that infects spiders, than to an insect-infecting mermithid collected on Oahu, HI, or to Mermis nigrescens, also a parasite of insects. Measured infection prevalence was low (ranging from 0 to 4%) but differed significantly among forest fragments. Infection prevalence was associated significantly with fragment area, but not with spider density nor spider species richness. Results suggest that mermithid populations are sensitive to habitat fragmentation, but that changes in infection prevalence do not appear to affect spider community structure.

Self-made shelters protect spiders from predation

PubMed Central

Manicom, Carryn; Schwarzkopf, Lin; Alford, Ross A.; Schoener, Thomas W.

2008-01-01

Many animals modify their environments, apparently to reduce predation risk, but the success of such endeavors, and their impact on the density and distribution of populations, are rarely rigorously demonstrated. We staged a manipulative experiment to assess the effectiveness of self-made shelters by web spiders as protection from natural enemies. Scincid lizards were included or excluded from 21 replicated 200-m2 plots, and spiders therein were classified as exposed or sheltered, depending on whether they were uncovered in their web or hidden in cocoons, leaves/debris, or burrows. We found that exposed spiders were greatly affected by the presence of predatory scincid lizards, whereas sheltered spiders were not. More specifically, lizards, which forage close to the ground, reduced the abundance of exposed spiders by two-thirds but had no effect on the abundance of sheltered spiders. Sheltered spiders were able to avoid predation and share space with lizards, suggesting that shelter construction is a mechanism for reducing predation risk and has important population consequences. PMID:18772383

Vertical distribution of trace-element concentrations and occurrence of metallurgical slag particles in accumulated bed sediments of Lake Roosevelt, Washington, September 2002

USGS Publications Warehouse

Cox, S.E.; Bell, P.R.; Lowther, J.S.; Van Metre, P.C.

2005-01-01

Sediment cores were collected from six locations in Lake Roosevelt to determine the vertical distributions of trace-element concentrations in the accumulated sediments of Lake Roosevelt. Elevated concentrations of arsenic, cadmium, copper, lead, mercury, and zinc occurred throughout much of the accumulated sediments. Concentrations varied greatly within the sediment core profiles, often covering a range of 5 to 10 fold. Trace-element concentrations typically were largest below the surficial sediments in the lower one-half of each profile, with generally decreasing concentrations from the 1964 horizon to the surface of the core. The trace-element profiles reflect changes in historical discharges of trace elements to the Columbia River by an upstream smelter. All samples analyzed exceeded clean-up guidelines adopted by the Confederated Tribes of the Colville Reservation for cadmium, lead, and zinc and more than 70 percent of the samples exceeded cleanup guidelines for mercury, arsenic, and copper. Although 100 percent of the samples exceeded sediment guidelines for cadmium, lead, and zinc, surficial concentrations of arsenic, copper, and mercury in some cores were less than the sediment-quality guidelines. With the exception of copper, the trace-element profiles of the five cores collected along the pre-reservoir Columbia River channel typically showed trends of decreasing concentrations in sediments deposited after the 1964 time horizon. The decreasing concentrations of trace elements in the upper half of cores from along the pre-reservoir Columbia River showed a pattern of decreasing concentrations similar to reductions in trace-element loading in liquid effluent from an upstream smelter. Except for arsenic, trace-element concentrations typically were smaller at downstream reservoir locations along the pre-reservoir Columbia River. Trace-element concentration in sediments from the Spokane Arm of the reservoir showed distinct differences compared to the similarities observed in cores from along the pre-reservoir Columbia River. Particles of slag, which have physical and chemical characteristics of slag discharged to the Columbia River by a lead-zinc smelter upstream of the reservoir at Trail, British Columbia, were found in sediments of Lake Roosevelt. Slag particles are more common in the upstream reaches of the reservoir. The chemical composition of the interior matrix of slag collected from Lake Roosevelt closely approximated the reported elemental concentrations of fresh smelter slag, although evidence of slag weathering was observed. Exfoliation flakes were observed on the surface of weathered slag particles isolated from the core sediments. The concentrations of zinc on the exposed surface of slag grains were smaller than concentrations on interior surfaces. Weathering rinds also were observed in the cross section of weathered slag grains, indicating that the glassy slag material was undergoing hydration and chemical weathering. Trace elements observed in accumulated sediments in the middle and lower reaches of the reservoir are more likely due to the input from liquid effluent discharges compared to slag discharges from the upstream smelter.

Trace elements in stormflow, ash, and burned soil following the 2009 station fire in southern California

USGS Publications Warehouse

Burton, Carmen; Hoefen, Todd M.; Plumlee, Geoffrey S.; Baumberger, Katherine L.; Backlin, Adam R.; Gallegos, Elizabeth; Fisher, Robert N.

2016-01-01

Most research on the effects of wildfires on stream water quality has focused on suspended sediment and nutrients in streams and water bodies, and relatively little research has examined the effects of wildfires on trace elements. The purpose of this study was two-fold: 1) to determine the effect of the 2009 Station Fire in the Angeles National Forest northeast of Los Angeles, CA on trace element concentrations in streams, and 2) compare trace elements in post-fire stormflow water quality to criteria for aquatic life to determine if trace elements reached concentrations that can harm aquatic life. Pre-storm and stormflow water-quality samples were collected in streams located inside and outside of the burn area of the Station Fire. Ash and burned soil samples were collected from several locations within the perimeter of the Station Fire. Filtered concentrations of Fe, Mn, and Hg and total concentrations of most trace elements in storm samples were elevated as a result of the Station Fire. In contrast, filtered concentrations of Cu, Pb, Ni, and Se and total concentrations of Cu were elevated primarily due to storms and not the Station Fire. Total concentrations of Se and Zn were elevated as a result of both storms and the Station Fire. Suspended sediment in stormflows following the Station Fire was an important transport mechanism for trace elements. Cu, Pb, and Zn primarily originate from ash in the suspended sediment. Fe primarily originates from burned soil in the suspended sediment. As, Mn, and Ni originate from both ash and burned soil. Filtered concentrations of trace elements in stormwater samples affected by the Station Fire did not reach levels that were greater than criteria established for aquatic life. Total concentrations for Fe, Pb, Ni, and Zn were detected at concentrations above criteria established for aquatic life.

Sensitivity of trace element pyritization to pyrite oxidation processes

NASA Astrophysics Data System (ADS)

Moreira, Manuel; Díaz, Rut; Mendoza, Ursula; Capilla, Ramses; Böttcher, Michael; Luiza Albuquerque, Ana; Machado, Wilson

2014-05-01

Total trace elements concentration variability in marine sediments has been widely used as a proxy for redox conditions and marine paleoprodutivity. However, partial extraction procedures reduce influences of detrital sedimentary fractions, and information on trace element geochemical partitioning can contribute to provide comprehensive evidences on elemental sensitivity to particular processes. The potential effect of sedimentary pyrite re-oxidative cycling on the degree of trace metal pyritization (DTMP) has not been previously evaluated. This study investigates this effect in 4 sediment cores from the continental shelf under the influence of a tropical upwelling system (Cabo Frio, Brazil). The relation of DTMP with stable isotope signals (δ34SCRS) of chromium reducible sulfur, which becomes lighter in response to intense pyrite re-oxidative cycling in the study area, suggests high (As, Cd and Mn), low (Cu and Zn) or negligible (Cr and Ni) re-oxidation influences. The oldest, pyrite-richer sediments provide an apparent threshold for intense pyrite re-oxidation, after which most trace elements (As, Cd, Zn and Mn) presented more accentuated pyritization. A middle shelf core presented negative correlations of reactive (HCl-soluble) Mn, Cu and Ni with pyrite iron, suggesting Mn oxide (and associated metals) depletion in reaction with pyrite. Results provided evidences for coupled influences from both aerobic and anaerobic oxidative processes on trace elements incorporation into pyrite. Pyrite δ34S signatures under the oxic bottom water from the study area were similar to those from euxinic sedimentary environments, suggesting that pyrite re-oxidative cycling can affect trace element susceptibility to be incorporated and preserved into pyrite in a wide range of sedimentary conditions. The evaluation of trace elements sensitivity to these processes can contribute to improve the use of multiple DTMP data (e.g., as paleoredox proxies). Considering that S re-oxidative cycling is ubiquitous in many sedimentary conditions, such coupled use of DTMP and δ34SCRS proxies can be possibly applied to a large variety of sedimentary environments.

Trace Elements in Stormflow, Ash, and Burned Soil following the 2009 Station Fire in Southern California

PubMed Central

Burton, Carmen A.; Hoefen, Todd M.; Plumlee, Geoffrey S.; Baumberger, Katherine L.; Backlin, Adam R.; Gallegos, Elizabeth; Fisher, Robert N.

2016-01-01

Most research on the effects of wildfires on stream water quality has focused on suspended sediment and nutrients in streams and water bodies, and relatively little research has examined the effects of wildfires on trace elements. The purpose of this study was two-fold: 1) to determine the effect of the 2009 Station Fire in the Angeles National Forest northeast of Los Angeles, CA on trace element concentrations in streams, and 2) compare trace elements in post-fire stormflow water quality to criteria for aquatic life to determine if trace elements reached concentrations that can harm aquatic life. Pre-storm and stormflow water-quality samples were collected in streams located inside and outside of the burn area of the Station Fire. Ash and burned soil samples were collected from several locations within the perimeter of the Station Fire. Filtered concentrations of Fe, Mn, and Hg and total concentrations of most trace elements in storm samples were elevated as a result of the Station Fire. In contrast, filtered concentrations of Cu, Pb, Ni, and Se and total concentrations of Cu were elevated primarily due to storms and not the Station Fire. Total concentrations of Se and Zn were elevated as a result of both storms and the Station Fire. Suspended sediment in stormflows following the Station Fire was an important transport mechanism for trace elements. Cu, Pb, and Zn primarily originate from ash in the suspended sediment. Fe primarily originates from burned soil in the suspended sediment. As, Mn, and Ni originate from both ash and burned soil. Filtered concentrations of trace elements in stormwater samples affected by the Station Fire did not reach levels that were greater than criteria established for aquatic life. Total concentrations for Fe, Pb, Ni, and Zn were detected at concentrations above criteria established for aquatic life. PMID:27144270

Transmission of atmospherically derived trace elements through an undeveloped, forested Maryland watershed

USGS Publications Warehouse

Scudlark, J.R.; Rice, Karen C.; Conko, Kathryn M.; Bricker, Owen P.; Church, T.M.

2005-01-01

The transmission of atmospherically derived trace elements (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn) was evaluated in a small, undeveloped, forested watershed located in north-central Maryland. Atmospheric input was determined for wet-only and vegetative throughfall components. Annual throughfall fluxes were significantly enriched over incident precipitation for most elements, although some elements exhibited evidence of canopy release (Mn) or preferential uptake (As, Cr, and Se). Stream export was gauged based on systematic sampling under varied flow regimes. Particle loading appears to contribute significantly to watershed export (> 10%) for only As, Pb, and Fe, and then only during large precipitation/runoff events. The degree of watershed transmission for each trace element was evaluated based on a comparison of total, net atmospheric input (throughfall) to stream export over an annual hydrologic cycle. This comparison indicates that the atmospheric input of some elements (Al, Cd, Ni, Zn) is effectively transmitted through the watershed, but other elements (Pb, As, Se, Fe, Cr, Cu) appear to be strongly sequestered, in the respective orders noted. Results suggest that precipitation and subsequent soil pH are the primary factors that determine the mobility of sequestered trace element phases.To further resolve primary atmospheric and secondary weathering components, the geochemical model NETPATH was applied. Results indicate that minerals dissolved include chlorite, plagioclase feldspar, epidote, and potassium feldspar; phases formed were kaolinite, pyrite, and silica. The model also indicates that weathering processes contribute negligible amounts of trace elements to stream export, indicative of the unreactive orthoquartzite bedrock lithology underlying the watershed. Thus, the stream export of trace elements primarily reflects atmospheric deposition to the local watershed.

Observations on germ band development in the cellar spider Pholcus phalangioides.

PubMed

Turetzek, Natascha; Prpic, Nikola-Michael

2016-11-01

Most recent studies of spider embryonic development have focused on representatives of the species-rich group of entelegyne spiders (over 80 % of all extant species). Embryogenesis in the smaller spider groups, however, is less well studied. Here, we describe the development of the germ band in the spider species Pholcus phalangioides, a representative of the haplogyne spiders that are phylogenetically the sister group of the entelegyne spiders. We show that the transition from radially symmetric embryonic anlage to the bilaterally symmetric germ band involves the accumulation of cells in the centre of the embryonic anlage (primary thickening). These cells then disperse all across the embryonic anlage. A secondary thickening of cells then appears in the centre of the embryonic anlage, and this thickening expands and forms the segment addition zone. We also confirm that the major part of the opisthosoma initially develops as a tube shaped structure, and its segments are then sequentially folded down on the yolk during inversion. This special mode of opisthosoma formation has not been reported for entelegyne spiders, but a more comprehensive sampling of this diverse group is necessary to decide whether this peculiarity is indeed lacking in the entelegyne spiders.

Attending to detail by communal spider-eating spiders.

PubMed

Jackson, Robert R; Nelson, Ximena J

2012-07-01

Communal predators may often need to make especially intricate foraging decisions, as a predator's success may depend on the actions of its neighbours. Here,we consider the decisions made by Portia africana, a jumping spider (Salticidae) that preys on other spiders, including Oecobius amboseli (Oecobiidae), a small prey spider that lives under small sheets of silk (nests) on the walls of buildings. P. africana juveniles settle near oecobiid nests and then ambush oecobiids as they leave or enter the nest. Two or more P. africana juveniles sometimes settle at the same nest and, when an oecobiid is captured, the P. africana juveniles may share the meal. We investigated the joining decisions made by naïve P. africana juveniles. Experiments were based on using lures (dead spiders positioned in lifelike posture) arranged in a series of 17 different scenes defined by the presence/absence of a nest, the lure types present and the configuration of the lures and the nest. Our findings imply that P. africana juveniles make remarkably precise predatory decisions, with the variables that matter including whether a nest is present, the identity of spiders inside and outside a nest and how spiders are positioned relative to each other and the nest.

[Transcatheter embolization for huge pulmonary arteriovenous fistula using metallic "spider" and spring embolus--application of hand-made metallic "spider" using partial monorail technique].

PubMed

Hirota, S; Sako, M; Fujita, Y; Hasegawa, Y; Sugimoto, K; Suzuki, Y; Kono, M

1992-07-25

We performed transcatheter embolization in two cases with huge pulmonary arteriovenous fistula (AVF) using a metallic "spider" and spring embolus. Conventional spring embolus or detachable balloon could not be used in these cases. Metallic spider was indicated for pulmonary AVF with a feeding artery diameter of more than 16 mm to prevent embolus passing through the AVF. In the first case, we used large handmade metallic spiders of 25 mm in diameter followed by embolization by numerous spring coils. At that time, a partial monorail technique was newly devised to carry the large metallic spider into the feeding artery, otherwise the spider could not pass into a 9F catheter. After embolization, symptoms and PaO2 in arterial blood improved remarkably in both cases. In the second case, a spring coil migrated into the normal pulmonary artery, but no infarction resulted. In conclusion, the metallic spider was very useful for embolization of hugee pulmonary AVF to avoid the embolus passing through and to tangle spring coils together with it. If commercially available "spiders" are too small, ones can be made easily.

U.S. Geological Survey Trace Elements and related reports through 1953

USGS Publications Warehouse

Wallace, Jane H.; Blatcher, Virginia K.; Smith, Harriet B.

1954-01-01

This report combines and brings up-to-date the information previously given in Trace Elements Investigations Report 325, "Numerical list of U.S. Geological Survey Trace Elements Reports to April 30, 1953," and Trace Elements Investigations Report 301, "Topical index and bibliography of U.S. Geological Survey Trace Elements and related reports." Part I is a numerical list of U.S. Geological Survey Trace Elements Investigations and Memorandum reports. It supersedes TEI-325. This part lists not only reports (followed by a date) that have been transmitted to the U.S. Atomic Energy Commission, but also reports in preparation (followed by an asterisk) for which tentative titles were available on December 31, 1953. Reports that have been published are indicated by the abbreviation of the medium of publication. (See also part II.) Part II is a reference guide to Trace Elements and related reports that are available to the public; this part supersedes Part 2 of the TEI-301 (published as Geological survey Circular 281). These reports are grouped according to the type of publication or release. Abstracts published in Nuclear Science Abstracts are not included in Part II, although certain TEI and TEM reports, the abstracts of which have been published in NSA, are so indicated in Part I. Publications in process on December 31, 1953, are designated by an asterisk. Part III is a finding list of states, areas, and subjects. It is based on information derived mostly from the titles of reports and, where titles are of a general nature, from a cursory review of the reports. This list is not a complete index of the information given in Trace Elements and related reports, but is designed to find subjects of major interest. Because of the numerous entries for Colorado and Utah, information has been listed by counties and, where possible, by subject under these states. Other states have county listings only if a county is included in the title of a report; otherwise, areas may be listed separately under the state. Major subjects are listed separately in the index and also where appropriate under states. Analytical methods and subjects related to analytical research are listed under Analytical Methods and Research, but not separately throughout the index. Most mineralogic studies are included under the heading Mineralogy, but are not necessarily listed according to location. Part IV is a finding list of authors. The words “with” and “and” are used to indicate seniority of authorship. For example, a listing of Jones and Brown indicates that Jones is the senior author. A listing of Jones with Brown indicates that Brown is the senior author. In both parts III and IV all Trace Elements reports are listed, as well as other related reports that have not been issued as Trace Elements reports. The following standard abbreviations have been used: TEI, Trace Elements Investigations report; TEM, Trace Elements Memorandum report; P, Professional Paper; B, Bulletin; C, Circular; J, Journal; OF, open file; TIS, Technical Information Service release; NSA, Nuclear Science Abstracts; QM, Quadrangle Map Series; and OM, Oil and Gas map or Mineral Investigations map or report.

Factors that influence the beta-diversity of spider communities in northwestern Argentinean Grasslands

PubMed Central

Rodriguez-Artigas, Sandra M.; Ballester, Rodrigo

2016-01-01

Beta-diversity, defined as spatial replacement in species composition, is crucial to the understanding of how local communities assemble. These changes can be driven by environmental or geographic factors (such as geographic distance), or a combination of the two. Spiders have been shown to be good indicators of environmental quality. Accordingly, spiders are used in this work as model taxa to establish whether there is a decrease in community similarity that corresponds to geographic distance in the grasslands of the Campos & Malezales ecoregion (Corrientes). Furthermore, the influence of climactic factors and local vegetation heterogeneity (environmental factors) on assemblage composition was evaluated. Finally, this study evaluated whether the differential dispersal capacity of spider families is a factor that influences their community structure at a regional scale. Spiders were collected with a G-Vac from vegetation in six grassland sites in the Campos & Malezales ecoregion that were separated by a minimum of 13 km. With this data, the impact of alpha-diversity and different environmental variables on the beta-diversity of spider communities was analysed. Likewise, the importance of species replacement and nesting on beta-diversity and their contribution to the regional diversity of spider families with different dispersion capacities was evaluated. The regional and site-specific inventories obtained were complete. The similarity between spider communities declined as the geographic distance between sites increased. Environmental variables also influenced community composition; stochastic events and abiotic forces were the principal intervening factors in assembly structure. The differential dispersal capacity of spider groups also influenced community structure at a regional scale. The regional beta-diversity, as well as species replacement, was greater in high and intermediate vagility spiders; while nesting was greater in spiders with low dispersion capacity. Geographic distance, among other factors (climate, and active and passive dispersion capacity), explains assembly structure and the decrease spider community similarity between geographically distant sites. Spiders with the highest dispersal capacity showed greater species replacement. This may be due to the discontinuity (both natural and anthropic) of the grasslands in this ecoregion, which limits the dispersal capacity of these spiders, and their close dependence on microhabitats. The dispersal capacity of the least vagile spiders is limited by geographic distance and biotic factors, such as competition, which could explain the nesting observed between their communities. PMID:27123380

Investigation of trace elements in ancient pottery from Jenini, Brong Ahafo region, Ghana by INAA and Compton suppression spectrometry

NASA Astrophysics Data System (ADS)

Nyarko, B. J. B.; Bredwa-Mensah, Y.; Serfor-Armah, Y.; Dampare, S. B.; Akaho, E. H. K.; Osae, S.; Perbi, A.; Chatt, A.

2007-10-01

Concentrations of trace elements in ancient pottery excavated from Jenini in the Brong Ahafo region of Ghana were determined using instrumental neutron activation analysis (INAA) in conjunction with both conventional and Compton suppression counting. Jenini was a slave Camp of Samory Toure during the indigenous slavery and the Trans-Atlantic slave trade. Pottery fragments found during the excavation of the grave tombs of the slaves who died in the slave camps were analysed. In all, 26 trace elements were determined in 40 pottery fragments. These elemental concentrations were processed using multivariate statistical methods, cluster, factor and discriminant analyses in order to determine similarities and correlation between the various samples. The suitability of the two counting systems for determination of trace elements in pottery objects has been evaluated.

Environmental influence on trace element levels in human hair

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

Limic, N.; Valkovic, V.

1986-12-01

Trace element content of human hair depends on many factors. It has been shown by a large number of investigators that environmental factors play an important role. Elements from air particulates, water, shampoo or other media get incorporated into the hair structure. Here a model is proposed in which different contributions to trace element levels in human hair are factorized and the environmental contribution to the radial and longitudinal concentration profiles can be calculated. With the proper understanding of environmental contamination, hair analysis has better chances of being used as a diagnostic tool.

Did You Say Spiders?

ERIC Educational Resources Information Center

Campbell, Alene

This spider unit focuses on students' development of cooperative learning and inquiry-based skills. Students read "The Very Busy Spider" by Eric Carle, and then work in cooperative groups using the Internet to research and synthesize important information about spiders. Technology is used for vocabulary instruction and to create a…

Risk of spider predation alters food web structure and reduces local herbivory in the field.

PubMed

Bucher, Roman; Menzel, Florian; Entling, Martin H

2015-06-01

Predators can indirectly enhance plant performance via herbivore suppression, with both prey consumption and changes in prey traits (e.g. changes in foraging behaviour) contributing to the reduction in herbivory. We performed a field experiment to determine the extent of such non-consumptive effects which consisted of repeatedly placing spiders (Pisaura mirabilis) on enclosed plants (Urtica dioica) for cue deposition. Control plants were enclosed in the same way but without spiders. After cue deposition, the enclosures were removed to allow arthropods to colonize the plants and feed on them. Arthropods were removed from the plants before the subsequent spider deposition or control enclosure. During six cycles of enclosure, we quantified leaf damage on the plants. After a seventh cycle, the colonizing arthropods were sampled to determine community composition in relation to the presence/absence of spider cues. We found that the presence of chemotactile spider cues reduced leaf damage by 50 %. In addition, spider cues led to changes in the arthropod community: smaller spiders avoided plants with spider cues. In contrast, the aphid-tending ant Myrmica rubra showed higher recruitment of workers on cue-bearing plants, possibly to protect aphids. Our results show that the risk of spider predation can reduce herbivory on wild plants and also demonstrate that non-consumptive effects can be particularly strong within the predator guild.

Spider (Araneae) predations on white-backed planthopper Sogatella furcifera in subtropical rice ecosystems, China.

PubMed

Wang, Xue-Qin; Wang, Guang-Hua; Zhu, Zeng-Rong; Tang, Qi-Yi; Hu, Yang; Qiao, Fei; Heong, Kong Luen; Cheng, Jia-An

2017-06-01

Spiders are effective biological control agents in rice ecosystems, but the comparative study of predations among main spider species under field conditions has not been fully explored owing to a lack of practical methodology. In this study, more than 6000 spiders of dominant species were collected from subtropical rice ecosystems to compare their predations on Sogatella furcifera (Horváth) (white-backed planthopper, WBPH) using DNA-based gut content analysis. The positive rates for all spider taxa were closely related to prey densities, as well as their behaviors and niches. The relationships of positive rates to prey planthopper densities for Pardosa pseudoannulata (Böes. et Str.), Coleosoma octomaculata (Böes. et Str.), Tetragnatha maxillosa Thorell and Ummeliata insecticeps (Böes. et Str.) under field conditions could be described using saturated response curves. Quantitative comparisons of predations among the four spider species confirmed that P. pseudoannulata and C. octomaculata were more rapacious than U. insecticeps and T. maxillosa under field conditions. A comparison of ratio of spiders to WBPH and positive rates between fields revealed that biological control by spiders could be effectively integrated with variety resistance. Generalist spiders could follow up WBPH population timely, and assemblages of spiders coupled with variety resistance could effectively suppress WBPH population. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Spider Transcriptomes Identify Ancient Large-Scale Gene Duplication Event Potentially Important in Silk Gland Evolution

PubMed Central

Clarke, Thomas H.; Garb, Jessica E.; Hayashi, Cheryl Y.; Arensburger, Peter; Ayoub, Nadia A.

2015-01-01

The evolution of specialized tissues with novel functions, such as the silk synthesizing glands in spiders, is likely an influential driver of adaptive success. Large-scale gene duplication events and subsequent paralog divergence are thought to be required for generating evolutionary novelty. Such an event has been proposed for spiders, but not tested. We de novo assembled transcriptomes from three cobweb weaving spider species. Based on phylogenetic analyses of gene families with representatives from each of the three species, we found numerous duplication events indicative of a whole genome or segmental duplication. We estimated the age of the gene duplications relative to several speciation events within spiders and arachnids and found that the duplications likely occurred after the divergence of scorpions (order Scorpionida) and spiders (order Araneae), but before the divergence of the spider suborders Mygalomorphae and Araneomorphae, near the evolutionary origin of spider silk glands. Transcripts that are expressed exclusively or primarily within black widow silk glands are more likely to have a paralog descended from the ancient duplication event and have elevated amino acid replacement rates compared with other transcripts. Thus, an ancient large-scale gene duplication event within the spider lineage was likely an important source of molecular novelty during the evolution of silk gland-specific expression. This duplication event may have provided genetic material for subsequent silk gland diversification in the true spiders (Araneomorphae). PMID:26058392

A virtual robot to model the use of regenerated legs in a web-building spider.

PubMed

Krink; Vollrath

1999-01-01

The garden cross orb-spider, Araneus diadematus, shows behavioural responses to leg loss and regeneration that are reflected in the geometry of the web's capture spiral. We created a virtual spider robot that mimicked the web construction behaviour of thus handicapped real spiders. We used this approach to test the correctness and consistency of hypotheses about orb web construction. The behaviour of our virtual robot was implemented in a rule-based system supervising behaviour patterns that communicated with the robot's sensors and motors. By building the typical web of a nonhandicapped spider our first model failed and led to new observations on real spiders. We realized that in addition to leg position, leg posture could also be of importance. The implementation of this new hypothesis greatly improved the results of our simulation of a handicapped spider. Now simulated webs, like the real webs of handicapped spiders, had significantly more gaps in successive spiral turns compared with webs of nonhandicapped spiders. Moreover, webs built by the improved virtual spiders intercepted prey as well as the digitized real webs. However, the main factors that affected web interception frequency were prey size, size of capture area and individual variance; having a regenerated leg, surprisingly, was relatively unimportant for this trait. Copyright 1999 The Association for the Study of Animal Behaviour.

Trace element biomonitoring using mosses in urban areas affected by mud volcanoes around Mt. Etna. The case of the Salinelle, Italy.

PubMed

Bonanno, Giuseppe; Lo Giudice, Rosa; Pavone, Pietro

2012-08-01

Trace element impact was assessed using mosses in a densely inhabited area affected by mud volcanoes. Such volcanoes, locally called Salinelle, are phenomena that occur around Mt. Etna (Sicily, Italy) and are interpreted as the surface outflow of a hydrothermal system located below Mt. Etna, releasing sedimentary fluids (hydrocarbons and NaCl brines) along with magmatic gases (mainly CO(2) and He). To date, scarce data are available about the presence of trace elements, and no biomonitoring campaigns are reported about the cumulative effects of such emissions. In this study, concentrations of Al, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn were detected in the moss Bryum argenteum, in soil and water. Results showed that the trace element contribution of the Salinelle to the general pollution was significant for Al, Mn, Ni, and Zn. The comparison of trace concentrations in mosses from Salinelle and Etna showed that the mud volcanoes release a greater amount of Al and Mn, whereas similar values of Ni were found. Natural emissions of trace elements could be hazardous in human settlements, in particular, the Salinelle seem to play an important role in environmental pollution.

Intercropping with white lupin (Lupinus albus L.); a promising tool for phytoremediation and phytomining research

NASA Astrophysics Data System (ADS)

Wiche, Oliver; Székely, Balazs; Moschner, Christin; Heilmeier, Hermann

2015-04-01

In recent studies root-soil interactions of white lupine (Lupinus albus L.) have drawn special attention to researchers due to its particularly high potential to increase bioavailability of phosphorous (P) and trace nutrients in soils. In mixed cultures, white lupine has the ability to mobilize P and trace nutrients in soil in excess of its own need and make this excess available for other intercropped companion species. While improved acquisition of P and improved yield parameters have mostly been documented in cereal-lupine intercrops, compared to sole crops, only a few recent studies have evidenced similar effects for trace elements e.g. Fe, Zn and Mn. In this preliminary study we tried to obtain more information about the mobilization of trace elements due to intercropping under field conditions. We hypothesize, that processes that lead to a better acquisition of trace nutrients might also affect other trace elements what could be useful for phytoremediation and phytomining research. Here we report the results of a semi-field experiment were we investigated the effects of an intercropping of white lupine with oat (Avena sativa L.) on the concentrations of trace metals in shoots of oat. We investigated the effects on 12 trace elements, including 4 elements with relevance for plant nutrition (P, Fe, Mn, Zn) and 8 trace elements, belonging to the group of metalloids, lanthanides and actinides with high relevance in phytoremediation (Cd, Pb Th, U) and phytomining research (Sc, La, Nd, Ge). The experiment was carried out on a semi-field lysimer at the off-site soil recycling and remediation center in Hirschfeld (Saxony, Germany). To test the intercropping-dependent mobilization of trace metals in soil and enhanced uptake of elements by oat, white lupine and oat were cultivated on 20 plots (4 m² each) in monocultures and mixed cultures and two different white lupin /oat-ratios (11% and 33%, respectively) applying various treatments. The geometrical arrangement of plots was randomized and every treatment was fivefold replicated. Soil solution was collected weekly with plastic suction cups. Concentrations of trace metals in shoots of oat and soil solution were measured with ICP-MS. As a result, we found that both, concentrations of trace elements in oat plants, as well as the mobility of P and trace metals in soil solution was increased by an intercropping with white lupine. Mixed culture of oat with 11% white lupin significantly increased the concentrations of the trace nutrients Fe, Mn and Zn, as well as the concentrations of the trace metals Pb, La, Nd, Sc, Th and U in tissues of oat. Surprisingly, mixed cultures with 33 % white lupin did not significantly affect trace metal concentrations in oat, what might be the consequence of an increasing competition of roots of white lupin and oat for nutrients and trace metals. In conclusion we found that mixed cultures of white lupin with cereals might be a powerful tool for enhanced phytoremediation and phytomining. However, processes involved in the physiochemical mechanism of element uptake as affected by the oat/white lupin co-cultivation remain unknown and further studies on this topic are planned. These studies have been carried out in the framework of the PhytoGerm project, financed by the Federal Ministry of Education and Research, Germany. The authors are grateful to students and laboratory assistants contributing in the field work and sample preparation.

Recent advances in the understanding of brown spider venoms: From the biology of spiders to the molecular mechanisms of toxins.

PubMed

Gremski, Luiza Helena; Trevisan-Silva, Dilza; Ferrer, Valéria Pereira; Matsubara, Fernando Hitomi; Meissner, Gabriel Otto; Wille, Ana Carolina Martins; Vuitika, Larissa; Dias-Lopes, Camila; Ullah, Anwar; de Moraes, Fábio Rogério; Chávez-Olórtegui, Carlos; Barbaro, Katia Cristina; Murakami, Mario Tyago; Arni, Raghuvir Krishnaswamy; Senff-Ribeiro, Andrea; Chaim, Olga Meiri; Veiga, Silvio Sanches

2014-06-01

The Loxosceles genus spiders (the brown spiders) are encountered in all the continents, and the clinical manifestations following spider bites include skin necrosis with gravitational lesion spreading and occasional systemic manifestations, such as intravascular hemolysis, thrombocytopenia and acute renal failure. Brown spider venoms are complex mixtures of toxins especially enriched in three molecular families: the phospholipases D, astacin-like metalloproteases and Inhibitor Cystine Knot (ICK) peptides. Other toxins with low level of expression also present in the venom include the serine proteases, serine protease inhibitors, hyaluronidases, allergen factors and translationally controlled tumor protein (TCTP). The mechanisms by which the Loxosceles venoms act and exert their noxious effects are not fully understood. Except for the brown spider venom phospholipase D, which causes dermonecrosis, hemolysis, thrombocytopenia and renal failure, the pathological activities of the other venom toxins remain unclear. The objective of the present review is to provide insights into the brown spider venoms and loxoscelism based on recent results. These insights include the biology of brown spiders, the clinical features of loxoscelism and the diagnosis and therapy of brown spider bites. Regarding the brown spider venom, this review includes a description of the novel toxins revealed by molecular biology and proteomics techniques, the data regarding three-dimensional toxin structures, and the mechanism of action of these molecules. Finally, the biotechnological applications of the venom components, especially for those toxins reported as recombinant molecules, and the challenges for future study are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cognitive reappraisal of snake and spider pictures: An event-related potentials study.

PubMed

Langeslag, Sandra J E; van Strien, Jan W

2018-05-30

Fear of snakes and spiders are common animal phobias. Emotion regulation can change the response to emotional stimuli, including snakes and spiders. It is well known that emotion regulation modulates the late positive potential (LPP), which reflects sustained motivated attention. However, research concerning the effect of emotion regulation on the early posterior negativity (EPN), which reflects early selective attention, is scarce. The present research question was whether the EPN and LPP amplitudes are modulated by regulation of emotional responses to snake and spider stimuli. Emotion up- and down-regulation were expected to enhance and reduce the LPP amplitude, respectively, but emotion regulation was not expected to modulate the EPN amplitude. Female participants passively viewed snake, spider, and bird pictures, and up- and down-regulated their emotional responses to the snake and spider pictures using self-focused reappraisal, while their electroencephalogram was recorded. There were EPNs for snakes and spiders vs. birds, as well as for snakes vs. spiders. The LPP amplitude tended to be enhanced for snakes and spiders compared to birds. Most importantly, the LPP amplitude was larger in the up-regulate than in the down-regulate condition for both snakes and spiders, but there was no evidence that the EPN amplitude was modulated by emotion regulation. This suggests that emotion regulation modulated sustained motivated attention, but not early selective attention, to snakes and spiders. The findings are in line with the notion that the emotional modulation of the EPN is more automatic than the emotional modulation of the LPP. Copyright © 2018 Elsevier B.V. All rights reserved.

[Contents of macromineral and trace elements in spirulina (Arthrospira platensis) from France, Chad, Togo, Niger, Mali, Burkina-Faso and Central African Republic].

PubMed

Vicat, Jean-Paul; Doumnang Mbaigane, Jean-Claude; Bellion, Yves

2014-01-01

Data on mineral elements in spirulinas being limited, we analyzed macrominerals and trace elements of samples from France and Africa. Spirulinas cultivated in France have a composition in macromineral elements similar to those of the literature. The entire contents of trace elements are low. Unlike marine cyanobacteria, they do not concentrate rare-earth elements. Spirulina harvested in Chad has high levels in macrominerals and trace elements, due to traditional drying and harvesting methods. Rare-earth element levels are attributed to this pollution and not to their concentration in spirulinas, because rare-earth element normalized profiles of spirulina are strictly parallel to those of ouadis mud and very different from those of ouadis water. Despite the sometimes high content of total As, normal water consumption in Chad presents no health problems. Spirulinas grown in Togo, Niger, Mali, Burkina-Faso and Central African Republic have chemical compositions similar to those of Chad spirulinas, but with a lower content of macromineral and trace elements, reflecting a lower mineral pollution. Rare-earth element normalized patterns dismiss an aeolian pollution and the pollution is rather of pedological origin. They show no toxicity problem except spirulinas from Burkina-Faso, whose Pb content is too high. The variability of composition of spirulinas can be largely attributed to the mineral pollution of the samples. Significant levels of rare-earth elements sometimes found in the literature reflect this pollution. Copyright © 2013 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Analysis of high-purity germanium dioxide by ETV-ICP-AES with preliminary concentration of trace elements.

PubMed

Medvedev, Nickolay S; Shaverina, Anastasiya V; Tsygankova, Alphiya R; Saprykin, Anatoly I

2016-08-01

The paper presents a combined technique of germanium dioxide analysis by inductively coupled plasma atomic emission spectrometry (ICP-AES) with preconcentration of trace elements by distilling off matrix and electrothermal (ETV) introduction of the trace elements concentrate into the ICP. Evaluation of metrological characteristics of the developed technique of high-purity germanium dioxide analysis was performed. The limits of detection (LODs) for 25 trace elements ranged from 0.05 to 20ng/g. The accuracy of proposed technique is confirmed by "added-found" («or spiking») experiment and comparing the results of ETV-ICP-AES and ICP-AES analysis of high purity germanium dioxide samples. Copyright © 2016 Elsevier B.V. All rights reserved.

A soil sampling reference site: the challenge in defining reference material for sampling.

PubMed

de Zorzi, Paolo; Barbizzi, Sabrina; Belli, Maria; Fajgelj, Ales; Jacimovic, Radojko; Jeran, Zvonka; Sansone, Umberto; van der Perk, Marcel

2008-11-01

In the frame of the international SOILSAMP project, funded and coordinated by the Italian Environmental Protection Agency, an agricultural area was established as a reference site suitable for performing soil sampling inter-comparison exercises. The reference site was characterized for trace element content in soil, in terms of the spatial and temporal variability of their mass fraction. Considering that the behaviour of long-lived radionuclides in soil can be expected to be similar to that of some stable trace elements and that the distribution of these trace elements in soil can simulate the distribution of radionuclides, the reference site characterised in term of trace elements, can be also used to compare the soil sampling strategies developed for radionuclide investigations.

Pituitary gland levels of mercury, selenium, iron, and zinc in an Alzheimer`s disease study

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

Cornett, C.R.; Markesbery, W.R.; Wekstein, D.R.

1996-12-31

Mercury, iron, selenium, and zinc imbalances have been observed in comparisons between Alzheimer`s disease (AD) and control subject brains. Analyses of the pituitary gland have demonstrated that this organ retains relatively high concentrations of trace elements, including mercury, iron, and zinc. Our previous work has shown that the pituitary glands of AD and control subjects are typically higher in these trace elements than brain samples from the same subject. Instrumental neutron activation analysis (INAA) was used to compare the pituitary trace element levels of AD and control subjects. This study also describes the intrasubject relationships of brain trace element levelsmore » to those in the pituitary gland of AD and control subjects.« less

High School Students' Attitudes towards Spiders: A Cross-Cultural Comparison

ERIC Educational Resources Information Center

Prokop, Pavol; Tolarovicova, Andrea; Camerik, Anne M.; Peterkova, Viera

2010-01-01

Spiders are traditionally considered to be among the least popular of animals. Current evidence suggests that a negative attitude towards spiders could be influenced by both cultural and evolutionary pressures. Some researchers suggest that science education activities could positively influence students' perceptions of spiders. Their evidence is,…

Passive degassing at Nyiragongo (D.R. Congo) and Etna (Italy) volcanoes: the chemical characterization of the emissions and assessment of their uptake of trace elements emissions on the local environment

NASA Astrophysics Data System (ADS)

Calabrese, Sergio; Scaglione, Sarah; Milazzo, Silvia; D'Alessandro, Walter; Bobrowski, Nicole; Giuffrida, Giovanni; Tedesco, Dario; Parello, Francesco

2014-05-01

Volcanoes are well known as an impressive large natural source of trace elements into the troposphere. Among others, Etna (Italy) and Nyiragongo (D.R. Congo), two noteworthy emitters on Earth, are two stratovolcanoes located in different geological settings, both characterized by persistent passive degassing from their summit craters. Here, we present some results on trace element composition in volcanic plume emissions, atmospheric bulk deposition (rainwater) and their uptake of the surrounding vegetation, with the aim to compare and identify differences and similarities between this these two volcanoes. Volcanic emissions were sampled by using active filter-pack for acid gases (sulfur and halogens) and specific teflon filters for particulates (major and trace elements). The impact of the volcanogenic deposition in the surrounding of the crater rims was investigated by using different sampling techniques: bulk rain collectors gauges were used to collect atmospheric bulk deposition, and biomonitoring technique was carried out to collect gases and particulates by using endemic plant species. Concentrations of major and trace elements of volcanic plume emissions (gases and particulates) were obtained by elution and microwave digestion of the collected filters: sulfur and halogens were determined by ion chromatography and ICP-MS, and untreated filters for particulate were acid digested and analysed by ICP-OES and ICP-MS. Rain water and plant samples were also analysed for major and trace elements by using ICP-OES and ICP-MS. In total 55 elements were determined. The estimates of the trace element fluxes confirm that Etna and Nyiragongo are large sources of metals to the atmosphere, especially considering their persistent state of passive degassing. In general, chemical composition of the volcanic aerosol particles of both volcanoes is characterized by two main components: one is related to the silicic component produced by magma bursting and fragmentation, enriching the plume in Si, Al, Fe, Ti, Mg, Ca, Na, K and other trace elements like Ni, Cr, Co, Th and U; another one components, is dominated by volatile trace elements (As, Bi, Cd, Cu, Hg, Se, Te, Tl) related to the gas volatile phase (H2O, CO2, SO2, HCl, HF) and transported to the atmosphere mainly as hydro-soluble salts and/or in gaseous form in some cases. The large amount of emitted trace elements have a strong impact on the close surrounding of both volcanoes. This is clearly reflected by in the chemical composition of rain water collected at the summit areas both for Etna and Nyiragongo. In fact, rain water samples have low pH values (<2) and high concentrations of dissolved toxic metals. Moreover, the biomonitoring results highlight that bioaccumulation of trace elements is extremely high in the proximity of the crater rim and decreases with the distance from the active craters. In particular, we found a good correlation between volatile elements (Tl, As, Bi, Cd, Se, Cu) concentrations in the leaves of Senecio species collected in on both volcanoes, showing a clear influence of volcanic deposition.

Trace Element Analysis of Biological Samples.

ERIC Educational Resources Information Center

Veillon, Claude

1986-01-01

Reviews background of atomic absorption spectrometry techniques. Discusses problems encountered and precautions to be taken in determining trace elements in the parts-per-billion concentration range and below. Concentrates on determining chromium in biological samples by graphite furnace atomic absorption. Considers other elements, matrices, and…

Trace elements in streambed sediments of small subtropical streams on O'ahu, Hawai'i: Results from the USGS NAWQA program

USGS Publications Warehouse

De Carlo, E. H.; Tomlinson, M.S.; Anthony, S.S.

2005-01-01

Data are presented for trace element concentrations determined in the <63 ??m fraction of streambed sediment samples collected at 24 sites on the island of O'ahu, Hawai'i. Sampling sites were classified as urban, agricultural, mixed (urban/agricultural), or forested based on their dominant land use, although the mixed land use at selected sampling sites consisted of either urban and agricultural or forested and agricultural land uses. Forest dominated sites were used as reference sites for calculating enrichment factors. Trace element concentrations were compared to concentrations from studies conducted in the conterminous United States using identical methods and to aquatic-life guidelines provided by the Canadian Council of Ministers of the Environment. A variety of elements including Pb, Cr, Cu and Zn exceeded the aquatic-life guidelines in selected samples. All of the Cr and Zn values and 16 of 24 Cu values exceeded their respective guidelines. The potential toxicity of elements exceeding guidelines, however, should be considered in the context of strong enrichments of selected trace elements attributable to source rocks in Hawai'i, as well as in the context of the abundance of fine-grained sediment in the streambed of O'ahu streams. Statistical methods including cluster analysis, Kruskal-Wallis non-parametric test, correlation analysis, and principal component analysis (PCA) were used to evaluate differences and elucidate relationships between trace elements and sites. Overall, trace element distributions and abundances can be correlated to three principal sources of elements. These include basaltic rocks of the volcanic edifice (Fe, Al, Ni, Co, Cr, V and Cu), carbonate/seawater derived elements (Mg, Ca, Na and Sr), and elements enriched owing to anthropogenic activity (P, Sn, Cd, Sn, Ba and Pb). Anthropogenic enrichment gradients were observed for Ba, Cd, Pb, Sn and Zn in the four streams in which sediments were collected upstream and downstream. The findings of this study are generally similar to but differ slightly from previous work on sediments and suspended particulate matter in streams, from two urban watersheds of O'ahu, Hawai'i. Inter-element associations in the latter were often stronger and indicated a mixture of anthropogenic, agricultural and basaltic sources of trace elements. Some elements fell into different statistical categories in the two studies, owing in part to differences in study design and the hydrogeological constraints on the respective study areas.

The occurrence of trace elements in bed sediment collected from areas of varying land use and potential effects on stream macroinvertebrates in the conterminous western United States, Alaska, and Hawaii, 1992-2000

USGS Publications Warehouse

Paul, Angela P.; Paretti, Nicholas V.; MacCoy, Dorene E.; Brasher, Anne M.D.

2012-01-01

As part of the National Water-Quality Assessment Program of the U.S. Geological Survey, this study examines the occurrence of nine trace elements in bed sediment of varying mineralogy and land use and assesses the possible effects of these trace elements on aquatic-macroinvertebrate community structure. Samples of bed sediment and macroinvertebrates were collected from 154 streams at sites representative of undeveloped, agricultural, urban, mined, or mixed land-use areas and 12 intermediate-scale ecoregions within the conterminous western United States, Alaska, and Hawaii from 1992 to 2000. The nine trace elements evaluated during this study—arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn)—were selected on the basis of potential ecologic significance and availability of sediment-quality guidelines. At most sites, the occurrence of these trace elements in bed sediment was at concentrations consistent with natural geochemical abundance, and the lowest concentrations were in bed-sediment samples collected from streams in undeveloped and agricultural areas. With the exception of Zn at sampling sites influenced by historic mining-related activities, median concentrations of all nine trace elements in bed sediment collected from sites representative of the five general land-use areas were below concentrations predicted to be harmful to aquatic macroinvertebrates. The highest concentrations of As, Cd, Pb, and Zn were in bed sediment collected from mined areas. Median concentrations of Cu and Ni in bed sediment were similarly enriched in areas of mining, urban, and mixed land use. Concentrations of Cr and Ni appear to originate largely from geologic sources, especially in the western coastal states (California, Oregon, and Washington), Alaska, and Hawaii. In these areas, naturally high concentrations of Cr and Ni can exceed concentrations that may adversely affect aquatic macroinvertebrates. Generally, Hg concentrations were below the sediment-quality guideline for this trace element but appeared elevated in urbanized areas and at sites contaminated by historic mining practices. Lastly, although there was no distinctive pattern in Se concentrations with land use, median bed-sediment concentrations were slightly elevated in urbanized areas.Macroinvertebrate community structure was influenced by topographic, geologic, climatic, and in-stream characteristics. To account for inherent distribution patterns resulting from these influences, samples of macroinvertebrates were stratified by ecoregion to assess the influence of trace elements on community structure. Cumulative toxic units (CTUs) were used to evaluate gradients in trace-element concentrations in mixture. Correlation analyses among the trace elements under different land-use conditions indicate that trace-element mixtures vary among bed sediment and can have a marked influence on CTU composition. Macroinvertebrate response to bed-sediment trace-element exposure was evident only at the most highly contaminated sites, notably at sites classified as contaminated by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) as a result of historic mining activities. Results of this study agree with the findings of other studies evaluating trace-element exposure to in-stream macroinvertebrate community structure in that generally lower richness metrics and taxa dominance occur in streams where high trace-element enrichment occurs; however, not all streams in all areas have the same characterizing taxa. In the mountain and xeric ecosystems, the mayfly, Baetis sp.; the Diptera, Simulium sp.; caddisflies in the family Hydropsychiidae; midges in the family Orthocladiinae; and the worms belonging to Turbellaria and Naididae all demonstrated resilience to trace-element exposure and, in some cases, possible changes in physical habitat within stream ecosystems. The taxa characteristics within the Ozark Highland ecoregion were different than other ecoregions as evidenced by generally more diverse mayfly populations. In addition, Baetis sp. was common and dominated many of the mayfly populations found in the Rocky Mountain streams within the Mountain Southern Rockies and Mountain Northern Rockies ecoregions; however, within the Ozark Highland ecoregion, Tricorythodes sp. appeared to be more common than Baetis sp.

Trace element bias in the use of CO2 vents as analogues for low pH environments: Implications for contamination levels in acidified oceans

NASA Astrophysics Data System (ADS)

Vizzini, S.; Di Leonardo, R.; Costa, V.; Tramati, C. D.; Luzzu, F.; Mazzola, A.

2013-12-01

Research into the effects of ocean acidification on marine ecosystems has increasingly focused on natural CO2 vents, although their intrinsic environmental complexity means observations from these areas may not relate exclusively to pH gradients. In order to assess trace element levels and distribution in the Levante Bay (Vulcano Island, NE Sicily, Italy) and its suitability for studying biological effects of pH decline, Ba, Fe and trace elements (As, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, V and Zn) in sediment were analysed from 7 transects. Where present, Cymodocea nodosa leaves and epiphytes were also analysed. At the spatial scale of the bay, trace element concentrations in sediments and biota showed wide variability, possibly related to both input from fluid emissions and seawater physico-chemical variables (i.e. pH and Eh), which may considerably affect the solubility and bioavailability of potentially harmful trace elements. According to two pollution indices (MSPI: Marine Sediment Pollution Index and SQG-Q: Sediment Quality Guideline Quotient), the bay can be considered to be affected by low contamination with moderate potential for adverse biological effects, especially in the area between about 150 and 350 m from the primary vent, where localized detrimental effects on biota may occur. Generally, biological samples showed concentrations that were comparable with the lower values of seagrass ranges. The overall results of this study support the complex spatial dynamics of trace elements in the CO2 vent studied, which are constrained by both direct input from the vent and/or biogeochemical processes affecting element precipitation at the sediment-seawater interface. Consequently, great caution should be used when relating biological changes along pH gradients to the unifactorial effect of pH only, as interactions with concurrent, multiple stressors, including trace element enrichments, may occur. This finding has implications for the use of CO2 vents as analogues in ocean acidification research. They should be considered more appropriately as analogues for low pH environments with non-negligible trace element contamination which, in a scenario of continuous increase in anthropogenic pollution, may be very common.

Trace elements in sediments, blue spotted tilapia Oreochromis leucostictus (Trewavas, 1933) and its parasite Contracaecum multipapillatum from Lake Naivasha, Kenya, including a comprehensive health risk analysis.

PubMed

Otachi, Elick O; Körner, Wilfried; Avenant-Oldewage, Annemariè; Fellner-Frank, Christine; Jirsa, Franz

2014-06-01

This study presents the distribution of 15 major and trace elements in sediments and fish and their pericardial parasites from Lake Naivasha, Kenya. The lake is one of the few freshwater lakes in the Great Rift Valley and is under strong anthropogenic pressure mainly due to agricultural activities. Its fish provide a valuable protein source for approximately 100,000 people in the area. Fish and their parasites have been acknowledged as indicators of environmental quality due to their accumulation potential for both essential and nonessential trace elements. A total of 34 specimens of the blue spotted tilapia Oreochromis leucostictus and pooled samples of their pericardial parasite, the anisakid nematode Contracaecum multipapillatum (larvae 3), were examined. Element concentrations were determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and graphite furnace atomic absorption spectrometry (GF-AAS). The concentrations of elements in the sediments reflected the geology of the area and did not point to pollution: none of the investigated trace elements, including Pb, Cd, Cu, and Zn, showed elevated values. In contrast, concentrations in the fish muscle were elevated for Li, Sr, Cd, and Zn, with high target hazard quotients (THQ > 0.1) indicating a potential health risk to the consumers of this fish. Fish liver showed significantly higher concentrations of the trace elements Fe, Mn, Cd, and Cu compared to the muscle and C. multipapillatum. In the parasite, Zn had the highest concentration, but the worms only minimally accumulated trace elements in relation to their fish host.

Rapid screening of heavy metals and trace elements in environmental samples using portable X-ray fluorescence spectrometer, A comparative study

PubMed Central

McComb, Jacqueline Q.; Rogers, Christian; Han, Fengxiang X.; Tchounwou, Paul B.

2014-01-01

With industrialization, great amounts of trace elements and heavy metals have been excavated and released on the surface of the earth and dissipated into the environments. Rapid screening technology for detecting major and trace elements as well as heavy metals in variety of environmental samples is most desired. The objectives of this study were to determine the detection limits, accuracy, repeatability and efficiency of a X-ray fluorescence spectrometer (Niton XRF analyzer) in comparison with the traditional analytical methods, inductively coupled plasma optical emission spectrometer (ICP-OES) and inductively coupled plasma optical emission spectrometer (ICP-MS) in screening of major and trace elements of environmental samples including estuary soils and sediments, contaminated soils, and biological samples. XRF is a fast and non-destructive method in measuring the total concentration of multi--elements simultaneously. Contrary to ICP-OES and ICP-MS, XRF analyzer is characterized by the limited preparation required for solid samples, non-destructive analysis, increased total speed and high throughout, the decreased production of hazardous waste and the low running costs as well as multi-elemental determination and portability in the fields. The current comparative study demonstrates that XRF is a good rapid non-destructive method for contaminated soils, sediments and biological samples containing higher concentrations of major and trace elements. Unfortunately, XRF does not have sensitive detection limits of most major and trace elements as ICP-OES or ICP-MS but it may serve as a rapid screening tool for locating hot spots of uncontaminated field soils and sediments. PMID:25861136

Growth and elemental content of two tree species growing on abandoned coal fly ash basins. [Liquidambar styraciflua L. ; Platanus occidentalis

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

Carlson, C.L.; Adriano, D.C.

Differences in aboveground tissue concentrations of trace elements were assessed for sweetgum (Liquidambar styraciflua L.) and sycamore (Plantanus occidentalis L.) growing on two abandoned coal fly ash basins and a control soil. The wet basin (pH = 5.58) had originally received precipitator ash in an ash-water slurry, while the dry basin (pH = 8.26) had received both precipitator and bottom ash in dry form. In general, trees from the wet basin exhibited elevated trace element concentrations in comparison to the controls, while the dry basin trees exhibited reduced concentrations. On eof the most striking differenced in elemental concentrations among themore » ash basin and control trees was observed for Mn, with the control trees exhibiting concentrations orders of magnitude greater than the ash basin trees. Differences in foliar trace element concentrations among the sites can generally be explained by differences in substrate trace element concentrations and/or substrate pH. While trees from the wet ash basin generally had the highest trace element concentrations, these trees also attained the greatest height and diameter growth, suggesting that the elevated trace element concentrations in the wet basin substrate are not limiting the establishment of these two species. The greater height and diameter growth of the wet basin trees is presumably a result of the greater water-holding capacity of the substrate on this site. Differences in growth and tissue concentrations between sweetgum and sycamore highlight the importance of using more than one species when assessing metal toxicity or deficiency on a given substrate.« less

Laser Doppler vibrometer measurement on spiders in moving-coil loudspeakers

NASA Astrophysics Data System (ADS)

Kong, Xiaopeng; Zeng, Xinwu; Tian, Zhangfu

2014-12-01

The spider is the dominate stiffness to suspend the cone for a moving-coil loudspeaker unit, and is most commonly a concentrically corrugated fabric disk. A subwoofer closed box is designed to excite the tested spiders pneumatically, and the Laser Doppler Vibrometer (LDV) is used to measure the velocity of the moving spiders. The effective stiffness, loss factor and some viscoelastic behaviors such as level dependent stiffness have been investigated. The results find that, this pneumatic non-contact dynamic technique successfully measured the viscoelastic behaviors of spiders from extremely low frequency 5 Hz to 200 Hz, and the effective stiffness of spiders is dependent on the input voltage level, which is higher level with lower stiffness.

Notes on spider (Theridiidae, Salticidae) predation of the harvester ant, Pogonomyrmex salinus Olsen (Hymenoptera: Formicidae: Myrmicinae), and a possible parasitoid fly (Chloropidae)

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

Clark, W.H.; Blom, P.E.

1992-12-01

Spiders are known predators of ants. Pressure exerted by consistent spider predation can alter the behavior of ant colonies (MacKay 1982) and may be a selective pressure contributing to the seed-harvesting behavior of Pogonomyrmex (MacKay and MacKay 1984). The authors observed the spider Euryopis formosa Banks (Araneae: Theridiidae) capture and transport workers of the harvester ant (Pogonomyrmex salinus Olsen [Hymenoptera: Formicidae, Myrmicinae]) in southeastern Idaho. Additional observations revealed a crab spider of the genus Xysticus preying on P. salinus and the presence of a chloropid fly (Incertella) that may have been parasitizing the moribund prey subdued by the spider.

Chemometric evaluation of concentrations of trace elements in intervertebral disc tissue in patient with degenerative disc disease.

PubMed

Kubaszewski, Łukasz; Zioła-Frankowska, Anetta; Gasik, Zuzanna; Frankowski, Marcin; Dąbrowski, Mikołaj; Molisak, Bartłomiej; Kaczmarczyk, Jacek; Gasik, Robert

2017-12-23

The work is designed to uncover the pattern of mutual relation among trace elements and epidemiological data in the degenerated intervertebral disk tissue in humans. Hitherto the reason of the degenerative process is not fully understood. Trace elements are the basic components of the biological compound related both its metabolism as well as environmental exposure. The relation pattern among elements occurs gives new perspective in solving the cause of the disease. We have analysed trace elements content in the 30 intervertebral disc from 22 patients with degenerative disc disease. The concentrations of Al, Cu, Cd, Mo, Ni and Pb were determined with Atomic Absorption Spectrometry. To analyse the multidimentional relation between trace element concentration and epidemiological data the chemometric analysis was applied. The similarity have been shown in occurrence of following pairs: Cd-Mo as well as Mg-Zn. The second pair was correlated with Pb concentration. Pb levels are observed to be competitive to Cu concentration. Cd concentration was related to Zn and Mg deficiency. No single but rather cluster of epidemiological data show observable influence on the TE tissue variance. Zn and Cu was related to the male sex. Operation with orthopedic implants were related to combined Al, Mo and Zn concentration. This is the first chemometric analysis of trace elements in disk tissue. It shows multidimentional relations that are missed by the classical statistic. The analysis shows significant relation. The nature of the relations is the basis for further metabolic and environmental research.

Australasian Society for Parenteral and Enteral Nutrition guidelines for supplementation of trace elements during parenteral nutrition.

PubMed

Osland, Emma J; Ali, Azmat; Isenring, Elizabeth; Ball, Patrick; Davis, Melvyn; Gillanders, Lyn

2014-01-01

This work represents the first part of a progressive review of AuSPEN's 1999 Guidelines for Provision of Micronutrient Supplementation in Adult Patients receiving Parenteral Nutrition, in recognition of the developments in the literature on this topic since that time. A systematic literature review was undertaken and recommendations were made based on the available evidence and with consideration to specific elements of the Australian and New Zealand practice environment. The strength of evidence underpinning each recommendation was assessed. External reviewers provided feedback on the guidelines using the AGREE II tool. Reduced doses of manganese, copper, chromium and molybdenum, and an increased dose of selenium are recommended when compared with the 1999 guidelines. Currently the composition of available multi-trace element formulations is recognised as an obstacle to aligning these guidelines with practice. A paucity of available literature and limitations with currently available methods of monitoring trace element status are acknowledged. The currently unknown clinical impact of changes to trace element contamination of parenteral solutions with contemporary practices highlights need for research and clinical vigilance in this area of nutrition support practice. Trace elements are essential and should be provided daily to patients receiving parenteral nutrition. Monitoring is generally only required in longer term parenteral nutrition, however should be determined on an individual basis. Industry is encouraged to modify existing multi-trace element solutions available in Australia and New Zealand to reflect changes in the literature outlined in these guidelines. Areas requiring research are highlighted.

Feasibility of the detection of trace elements in particulate matter using online High-Resolution Aerosol Mass Spectrometry

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

Salcedo, D.; Laskin, Alexander; Shutthanandan, V.

The feasibility of using an online thermal-desorption electron-ionization high-resolution aerosol mass spectrometer (AMS) for the detection of particulate trace elements was investigated analyzing data from Mexico City obtained during the MILAGRO 2006 field campaign, where relatively high concentrations of trace elements have been reported. This potential application is of interest due to the real-time data provided by the AMS, its high sensitivity and time resolution, and the widespread availability and use of this instrument. High resolution mass spectral analysis, isotopic ratios, and ratios of different ions containing the same elements are used to constrain the chemical identity of the measuredmore » ions. The detection of Cu, Zn, As, Se, Sn, and Sb is reported. There was no convincing evidence for the detection of other trace elements commonly reported in PM. The elements detected tend to be those with lower melting and boiling points, as expected given the use of a vaporizer at 600oC in this instrument. Operation of the AMS vaporizer at higher temperatures is likely to improve trace element detection. The detection limit is estimated at approximately 0.3 ng m-3 for 5-min of data averaging. Concentration time series obtained from the AMS data were compared to concentration records determined from offline analysis of particle samples from the same times and locations by ICP (PM2.5) and PIXE (PM1.1 and PM0.3). The degree of correlation and agreement between the three instruments (AMS, ICP, and PIXE) varied depending on the element. The AMS shows promise for real-time detection of some trace elements, although additional work including laboratory calibrations with different chemical forms of these elements are needed to further develop this technique and to understand the differences with the ambient data from the other techniques. The trace elements peaked in the morning as expected for primary sources, and the many detected plumes suggest the presence of multiple point sources, probably industrial, in Mexico City which are variable in time and space, in agreement with previous studies.« less

Optimizing detector geometry for trace element mapping by X-ray fluorescence.

PubMed

Sun, Yue; Gleber, Sophie-Charlotte; Jacobsen, Chris; Kirz, Janos; Vogt, Stefan

2015-05-01

Trace metals play critical roles in a variety of systems, ranging from cells to photovoltaics. X-Ray Fluorescence (XRF) microscopy using X-ray excitation provides one of the highest sensitivities available for imaging the distribution of trace metals at sub-100 nm resolution. With the growing availability and increasing performance of synchrotron light source based instruments and X-ray nanofocusing optics, and with improvements in energy-dispersive XRF detectors, what are the factors that limit trace element detectability? To address this question, we describe an analytical model for the total signal incident on XRF detectors with various geometries, including the spectral response of energy dispersive detectors. This model agrees well with experimentally recorded X-ray fluorescence spectra, and involves much shorter calculation times than with Monte Carlo simulations. With such a model, one can estimate the signal when a trace element is illuminated with an X-ray beam, and when just the surrounding non-fluorescent material is illuminated. From this signal difference, a contrast parameter can be calculated and this can in turn be used to calculate the signal-to-noise ratio (S/N) for detecting a certain elemental concentration. We apply this model to the detection of trace amounts of zinc in biological materials, and to the detection of small quantities of arsenic in semiconductors. We conclude that increased detector collection solid angle is (nearly) always advantageous even when considering the scattered signal. However, given the choice between a smaller detector at 90° to the beam versus a larger detector at 180° (in a backscatter-like geometry), the 90° detector is better for trace element detection in thick samples, while the larger detector in 180° geometry is better suited to trace element detection in thin samples. Copyright © 2015. Published by Elsevier B.V.

Optimizing detector geometry for trace element mapping by X-ray fluorescence

PubMed Central

Sun, Yue; Gleber, Sophie-Charlotte; Jacobsen, Chris; Kirz, Janos; Vogt, Stefan

2016-01-01

Trace metals play critical roles in a variety of systems, ranging from cells to photovoltaics. X-Ray Fluorescence (XRF) microscopy using X-ray excitation provides one of the highest sensitivities available for imaging the distribution of trace metals at sub-100 nm resolution. With the growing availability and increasing performance of synchrotron light source based instruments and X-ray nanofocusing optics, and with improvements in energy-dispersive XRF detectors, what are the factors that limit trace element detectability? To address this question, we describe an analytical model for the total signal incident on XRF detectors with various geometries, including the spectral response of energy dispersive detectors. This model agrees well with experimentally recorded X-ray fluorescence spectra, and involves much shorter calculation times than with Monte Carlo simulations. With such a model, one can estimate the signal when a trace element is illuminated with an X-ray beam, and when just the surrounding non-fluorescent material is illuminated. From this signal difference, a contrast parameter can be calculated and this can in turn be used to calculate the signal-to-noise ratio (S/N) for detecting a certain elemental concentration. We apply this model to the detection of trace amounts of zinc in biological materials, and to the detection of small quantities of arsenic in semiconductors. We conclude that increased detector collection solid angle is (nearly) always advantageous even when considering the scattered signal. However, given the choice between a smaller detector at 90° to the beam versus a larger detector at 180° (in a backscatter-like geometry), the 90° detector is better for trace element detection in thick samples, while the larger detector in 180° geometry is better suited to trace element detection in thin samples. PMID:25600825

Optimizing detector geometry for trace element mapping by X-ray fluorescence

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

Sun, Yue; Gleber, Sophie-Charlotte; Jacobsen, Chris

Trace metals play critical roles in a variety of systems, ranging from cells to photovoltaics. X-Ray Fluorescence (XRF) microscopy using X-ray excitation provides one of the highest sensitivities available for imaging the distribution of trace metals at sub-100 nm resolution. With the growing availability and increasing performance of synchrotron light source based instruments and X-ray nanofocusing optics, and with improvements in energy-dispersive XRF detectors, what are the factors that limit trace element detectability? To address this question, we describe an analytical model for the total signal incident on XRF detectors with various geometries, including the spectral response of energy dispersivemore » detectors. This model agrees well with experimentally recorded X-ray fluorescence spectra, and involves much shorter calculation times than with Monte Carlo simulations. With such a model, one can estimate the signal when a trace element is illuminated with an X-ray beam, and when just the surrounding non-fluorescent material is illuminated. From this signal difference, a contrast parameter can be calculated and this can in turn be used to calculate the signal-to-noise ratio (S/N) for detecting a certain elemental concentration. We apply this model to the detection of trace amounts of zinc in biological materials, and to the detection of small quantities of arsenic in semiconductors. We conclude that increased detector collection solid angle is (nearly) always advantageous even when considering the scattered signal. However, given the choice between a smaller detector at 90° to the beam versus a larger detector at 180° (in a backscatter-like geometry), the 90° detector is better for trace element detection in thick samples, while the larger detector in 180° geometry is better suited to trace element detection in thin samples.« less

Concentration of trace elements on branded cigarette in Malaysia

NASA Astrophysics Data System (ADS)

Azman, Muhammad Azfar; Yasir, Muhamad Samudi; Rahman, Irman Abdul; Hamzah, Suhaimi; Rahman, Shamsiah Abdul; Elias, Md Suhaimi; Abdullah, Nazaratul Ashifa; Hashim, Azian; Shukor, Shakirah Abd

2016-01-01

Tobacco is a plant that is used as a recreational drug since the beginning of its use by the Native Americans. Now with the development of the tobacco industry, smoking has become a norm for the public in Malaysia. Trace elements in plants are mostly due to the uptake processes from the soils into the roots of the plants. The concentration of the elements may also be influenced by the elements contained in the water and also fertilizers. This paper aim to analyze the concentration of the trace elements contained in the branded cigarettes sold in Malaysia by utilizing the neutron activation analysis. The tobaccos were taken out from the cigarettes. The collected samples were air dried and passed through 2 mm sieve. Instrumental Neutron Activation Analysis (NAA) has been used for the determination of trace elements. Samples were activated in the Nuclear Malaysia Triga Mark II reactor with a neutron flux of 2.0 x 1012 n cm-2 s-1. The samples then were analyzed using ORTEC Gamma Spectrometer a co-axial n-type HPGe detector with resolution of 2.0 keV at 1332 keV and relative efficiency of 20%. The data obtained could help in assessing the concentration of the trace elements that complying with the standard limitation dose proposed by World Health Organization (WHO).

Rapid visuomotor processing of phobic images in spider- and snake-fearful participants.

PubMed

Haberkamp, Anke; Schmidt, Filipp; Schmidt, Thomas

2013-10-01

This study investigates enhanced visuomotor processing of phobic compared to fear-relevant and neutral stimuli. We used a response priming design to measure rapid, automatic motor activation by natural images (spiders, snakes, mushrooms, and flowers) in spider-fearful, snake-fearful, and control participants. We found strong priming effects in all tasks and conditions; however, results showed marked differences between groups. Most importantly, in the group of spider-fearful individuals, spider pictures had a strong and specific influence on even the fastest motor responses: Phobic primes entailed the largest priming effects, and phobic targets accelerated responses, both effects indicating speeded response activation by phobic images. In snake-fearful participants, this processing enhancement for phobic material was less pronounced and extended to both snake and spider images. We conclude that spider phobia leads to enhanced processing capacity for phobic images. We argue that this is enabled by long-term perceptual learning processes. © 2013.

Synergistic adhesion mechanisms of spider capture silk.

PubMed

Guo, Yang; Chang, Zheng; Guo, Hao-Yuan; Fang, Wei; Li, Qunyang; Zhao, Hong-Ping; Feng, Xi-Qiao; Gao, Huajian

2018-03-01

It is well known that capture silk, the main sticky component of the orb web of a spider, plays an important role in the spider's ability to capture prey via adhesion. However, the detailed mechanism with which the spider achieves its unparalleled high-adhesion performance remains elusive. In this work, we combine experiments and theoretical analysis to investigate the adhesion mechanisms of spider silk. In addition to the widely recognized adhesion effect of the sticky glue, we reveal a synergistic enhancement mechanism due to the elasticity of silk fibres. A balance between silk stiffness, strength and glue stickiness is crucial to endow the silk with superior adhesion, as well as outstanding energy absorption capacity and structural robustness. The revealed mechanisms deepen our understanding of the working principles of spider silk and suggest guidelines for biomimetic designs of spider-inspired adhesion and capture devices. © 2018 The Author(s).

Spiders in caves.

PubMed

Mammola, Stefano; Isaia, Marco

2017-04-26

World experts of different disciplines, from molecular biology to macro-ecology, recognize the value of cave ecosystems as ideal ecological and evolutionary laboratories. Among other subterranean taxa, spiders stand out as intriguing model organisms for their ecological role of top predators, their unique adaptations to the hypogean medium and their sensitivity to anthropogenic disturbance. As the description of the first eyeless spider ( Stalita taenaria ), an array of papers on subterranean spider biology, ecology and evolution has been published, but a comprehensive review on these topics is still lacking. We provide a general overview of the spider families recorded in hypogean habitats worldwide, we review the different adaptations of hypogean spiders to subterranean life, and we summarize the information gathered so far about their origin, population structure, ecology and conservation status. Finally, we point out the limits of the knowledge we currently have regarding hypogean spiders, aiming to stimulate future research. © 2017 The Author(s).

Spiders in caves

PubMed Central

2017-01-01

World experts of different disciplines, from molecular biology to macro-ecology, recognize the value of cave ecosystems as ideal ecological and evolutionary laboratories. Among other subterranean taxa, spiders stand out as intriguing model organisms for their ecological role of top predators, their unique adaptations to the hypogean medium and their sensitivity to anthropogenic disturbance. As the description of the first eyeless spider (Stalita taenaria), an array of papers on subterranean spider biology, ecology and evolution has been published, but a comprehensive review on these topics is still lacking. We provide a general overview of the spider families recorded in hypogean habitats worldwide, we review the different adaptations of hypogean spiders to subterranean life, and we summarize the information gathered so far about their origin, population structure, ecology and conservation status. Finally, we point out the limits of the knowledge we currently have regarding hypogean spiders, aiming to stimulate future research. PMID:28446696

Prey preference of the predatory mite, Amblyseius swirskii between first instar western flower thrips Frankliniella occidentalis and nymphs of the twospotted spider mite Tetranychus urticae.

PubMed

Xu, Xuenong; Enkegaard, Annie

2010-01-01

The prey preference of polyphagous predators plays an important role in suppressing different species of pest insects. In this study the prey preference of the predatory mite, Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) was examined between nymphs of the twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) and first instar larvae of the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), as well as between active and chrysalis spider mite protonymphs and active and chrysalis spider mite deutonymphs. The study was done in the laboratory on bean leaf discs at 25 ± 1° C and 70 ± 5% RH. Amblyseius swirskii had a clear preference for thrips compared to both spider mite protonymphs and deutonymphs. About twice as many thrips as spider mites were consumed. Amblyseius swirskii did not show a preference between active and chrysalis stages of spider mites.

Horizontal and vertical variability of soil properties in a trace element contaminated area

NASA Astrophysics Data System (ADS)

Burgos, Pilar; Madejón, Engracia; Pérez-de-Mora, Alfredo; Cabrera, Francisco

2008-02-01

The spatial distribution of some soil chemical properties and trace element contents of a plot affected by the Aznalcóllar mine spill were investigated using statistical and geostatistical methods to assess the extent of soil contamination. Total and EDTA-extractable soil trace element concentrations and total S content showed great variability and high coefficients of variation in the three examined depths. Soil in the plot was found to be significantly contaminated by As, Cd, Cu, Pb and Zn within a wide range of pH. Total trace element concentrations at all depths (0-60 cm) were much higher than background values of non-affected soil, indicating that despite the clean-up operations, the concentration of trace elements in the experimental plot was still high. The spatial distribution of the different variables was estimated by kriging to design contour maps. These maps allowed the identification of specific zones with high metal concentrations and low pH values corresponding to spots of residual sludge. Moreover, kriged maps showed distinct spatial distribution and hence different behaviour for the elements considered. This information may be applied to optimise remediation strategies in highly and moderately contaminated areas.

Geochemistry of zircons from basic rocks of the Korosten anorthosite-mangerite-charnockite-granite complex, north-western region of the Ukrainian Shield

NASA Astrophysics Data System (ADS)

Shumlyanskyy, Leonid; Belousova, Elena; Petrenko, Oksana

2017-09-01

The concentrations of 26 trace elements have been determined by laser ablation ICP-MS in zircons from four samples of basic rocks of the Korosten anorthosite-mangerite-charnockite-granite plutonic complex, the Ukrainian Shield. Zircons from the Fedorivka and Torchyn gabbroic intrusions and Volynsky anorthosite massif have distinctive abundances of many trace elements (REE, Sr, Y, Mn, Th). Zircons from the gabbroic massifs are unusually enriched in trace elements, while zircons from pegmatites in anorthosite are relatively depleted in trace elements. High concentrations of trace elements in zircons from gabbroic intrusions can be explained by their crystallization from residual interstitial melts enriched in incompatible elements. The zircons studied demonstrate a wide range of Ti concentrations, which reflects their temperature of crystallization: the zircons most enriched in Ti, from mafic pegmatites of the Horbuliv quarry (20-40 ppm), have the highest temperature of crystallization (845 ± 40 °C). Lower (720-770 °C) temperatures of zircon crystallization in gabbroic rocks are explained by its crystallization from the latest portions of the interstitial melt or by simultaneous crystallization of ilmenite. The Ce anomaly in zircons correlates with the degree of oxidation of the coexisting ilmenite.

Ion microprobe mass analysis of plagioclase from 'non-mare' lunar samples

NASA Technical Reports Server (NTRS)

Meyer, C., Jr.; Anderson, D. H.; Bradley, J. G.

1974-01-01

The ion microprobe was used to measure the composition and distribution of trace elements in lunar plagioclase, and these analyses are used as criteria in determining the possible origins of some nonmare lunar samples. The Apollo 16 samples with metaclastic texture and high-bulk trace-element contents contain plagioclase clasts with extremely low trace-element contents. These plagioclase inclusions represent unequilibrated relicts of anorthositic, noritic, or troctolitic rocks that have been intermixed as a rock flour into the KREEP-rich matrix of these samples. All of the plagioclase-rich inclusions which were analyzed in the KREEP-rich Apollo 14 breccias were found to be rich in trace elements. This does not seem to be consistent with the interpretation that the Apollo 14 samples represent a pre-Imbrium regolith, because such an ancient regolith should have contained many plagioclase clasts with low trace-element contents more typical of plagioclase from the pre-Imbrium crust. Ion-microprobe analyses for Ba and Sr in large plagioclase phenocrysts in 14310 and 68415 are consistent with the bulk compositions of these rocks and with the known distribution coefficients for these elements. The distribution coefficient for Li (basaltic liquid/plagioclase) was measured to be about 2.

Trace elemental analysis of bituminuos coals using the Heidelberg proton microprobe

USGS Publications Warehouse

Chen, J.R.; Kneis, H.; Martin, B.; Nobiling, R.; Traxel, K.; Chao, E.C.T.; Minkin, J.A.

1981-01-01

Trace elements in coal can occur as components of either the organic constituents (macerals) or the inorganic constituents (minerals). Studies of the concentrations and distribution of the trace elements are vital to understanding the geochemical millieu in which the coal was formed and in evaluating the attempts to recover rare but technologically valuable metals. In addition, information on the trace element concentrations is important in predicting the environmental impact of burning particular coals, as many countries move toward greater utilization of coal reserves for energy production. Traditionally, the optical and the electron microscopes and more recently the electron microprobe have been used in studying the components of coal. The proton-induced X-ray emission (PIXE) microprobe offers a new complementary approach with an order of magnitude or more better minimum detection limit. We present the first measurements with a PIXE microprobe of the trace element concentrations of bituminous coal samples. Elemental analyses of the coal macerals-vitrinite, exinite, and inertinite-are discussed for three coal samples from the Eastern U.S.A., three samples from the Western U.S.A., and one sample from the Peoples Republic of China. ?? 1981.

Silkworms transformed with chimeric silkworm/spider silk genes spin composite silk fibers with improved mechanical properties

USDA-ARS?s Scientific Manuscript database

The development of a spider silk manufacturing process is of great interest. piggyBac vectors were used to create transgenic silkworms encoding chimeric silkworm/spider silk proteins. The silk fibers produced by these animals were composite materials that included chimeric silkworm/spider silk prote...

Brain dynamics in spider-phobic individuals exposed to phobia-relevant and other emotional stimuli.

PubMed

Michalowski, Jaroslaw M; Melzig, Christiane A; Weike, Almut I; Stockburger, Jessica; Schupp, Harald T; Hamm, Alfons O

2009-06-01

Dense sensor event-related brain potentials were measured in participants with spider phobia and nonfearful controls during viewing of phobia-relevant spider and standard emotional (pleasant, unpleasant, neutral) pictures. Irrespective of the picture content, spider phobia participants responded with larger P1 amplitudes than controls, suggesting increased vigilance in this group. Furthermore, spider phobia participants showed a significantly enlarged early posterior negativity (EPN) and late positive potential (LPP) during the encoding of phobia-relevant pictures compared to nonfearful controls. No group differences were observed for standard emotional materials indicating that these effects were specific to phobia-relevant material. Within group comparisons of the spider phobia group, though, revealed comparable EPN and LPP evoked by spider pictures and emotional (unpleasant and pleasant) picture contents. These results demonstrate a temporal unfolding in perceptual processing from unspecific vigilance (P1) to preferential responding (EPN and LPP) to phobia-relevant materials in the spider phobia group. However, at the level of early stimulus processing, these effects of increased attention seem to be related to emotional relevance of the stimulus cues rather than reflecting a fear-specific response.

Heat Tolerance of the Brown Recluse Spider (Araneae: Sicariidae): Potential for Pest Control.

PubMed

Cramer, Kenneth L; Zagar, Lindsey M

2016-02-01

The brown recluse spider, Loxosceles reclusa Gertsch & Mulaik, is a well-known venomous spider common in the south-central United States where infestations can reach thousands of individuals in a single structure. Bites from this spider pose a risk of dermonecrotic lesions (loxoscelism) or, rarely, more serious systemic effects. The heat tolerance of this spider is understudied but may offer an alternative pest control solution to pesticides or fumigation, both of which have their disadvantages. We subjected brown recluse spiders to increasing temperatures to establish the upper lethal temperature (LT). Using probit analysis to generate probability of mortality at increasing temperatures, we then exposed adult spiders to the observed LT50 to simulate whole-room heat treatment. Laboratory results predict exposure to 48°C for 130 min will achieve 100% mortality of adult spiders. Field tests need to be conducted to determine the efficacy of heat treatment in a variety of real-world situations. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Placebo effects in spider phobia: an eye-tracking experiment.

PubMed

Gremsl, Andreas; Schwab, Daniela; Höfler, Carina; Schienle, Anne

2018-01-05

Several eye-tracking studies have revealed that spider phobic patients show a typical hypervigilance-avoidance pattern when confronted with images of spiders. The present experiment investigated if this pattern can be changed via placebo treatment. We conducted an eye-tracking experiment with 37 women with spider phobia. They looked at picture pairs (a spider paired with a neutral picture) for 7 s each in a retest design: once with and once without a placebo pill presented along with the verbal suggestion that it can reduce phobic symptoms. The placebo was labelled as Propranolol, a beta-blocker that has been successfully used to treat spider phobia. In the placebo condition, both the fixation count and the dwell time on the spider pictures increased, especially in the second half of the presentation time. This was associated with a slight decrease in self-reported symptom severity. In summary, we were able to show that a placebo was able to positively influence visual avoidance in spider phobia. This effect might help to overcome apprehension about engaging in exposure therapy, which is present in many phobic patients.

From Midges to Spiders: Mercury Biotransport in Riparian Zones Near the Buffalo River Area of Concern (AOC), USA.

PubMed

Pennuto, C M; Smith, M

2015-12-01

Riparian communities can receive environmental contaminants from adjacent aquatic 'donor' habitats. We investigated mercury biotransport from aquatic to terrestrial habitats via aquatic insect emergence and uptake by riparian spiders at sites within and upstream of the Buffalo River Area of Concern (AOC), a site with known sediment Hg contamination. Mercury concentration in emerging midges was roughly 10× less than contaminated sediment levels with the AOC, but biomagnification factors from midges to spiders ranged from 2.0 to 2.65 between sites. There was a significantly negative body mass:total mercury relationship in spiders (p < 0.001), indicating that mercury depuration is rapid or tissue dilution occurs in these riparian predators. Spiders contained significantly more mercury than their midge prey and spiders upstream of the AOC had higher mercury concentrations than spiders from within the AOC. Collectively, these data indicate that riparian spiders can be good mercury sentinels in urban environments, and that riparian communities upstream from the AOC may be at greater risk to mercury than has been previously considered.

Spatial and temporal variability of trace element concentrations in an urban subtropical watershed, Honolulu, Hawaii

USGS Publications Warehouse

Heinen, De Carlo E.; Anthony, S.S.

2002-01-01

Trace metal concentrations in soils and in stream and estuarine sediments from a subtropical urban watershed in Hawaii are presented. The results are placed in the context of historical studies of environmental quality (water, soils, and sediment) in Hawaii to elucidate sources of trace elements and the processes responsible for their distribution. This work builds on earlier studies on sediments of Ala Wai Canal of urban Honolulu by examining spatial and temporal variations in the trace elements throughout the watershed. Natural processes and anthropogenic activity in urban Honolulu contribute to spatial and temporal variations of trace element concentrations throughout the watershed. Enrichment of trace elements in watershed soils result, in some cases, from contributions attributed to the weathering of volcanic rocks, as well as to a more variable anthropogenic input that reflects changes in land use in Honolulu. Varying concentrations of As, Cd, Cu, Pb and Zn in sediments reflect about 60 a of anthropogenic activity in Honolulu. Land use has a strong impact on the spatial distribution and abundance of selected trace elements in soils and stream sediments. As noted in continental US settings, the phasing out of Pb-alkyl fuel additives has decreased Pb inputs to recently deposited estuarine sediments. Yet, a substantial historical anthropogenic Pb inventory remains in soils of the watershed and erosion of surface soils continues to contribute to its enrichment in estuarine sediments. Concentrations of other elements (e.g., Cu, Zn, Cd), however, have not decreased with time, suggesting continued active inputs. Concentrations of Ba, Co, Cr, Ni, V and U, although elevated in some cases, typically reflect greater proportions attributed to natural sources rather than anthropogenic input. ?? 2002 Elsevier Science Ltd. All rights reserved.

Potential role of peroxisome proliferator activated receptor gamma activation on serum visfatin and trace elements in high fat diet induced type 2 diabetes mellitus.

PubMed

Tabassum, Arshia; Zaidi, Syeda Nuzhat Fatima; Yasmeen, Kausar; Mahboob, Tabassum

2018-07-15

Electrolytes and trace elements dysregulation play an important role in the progression of obesity and diabetes complications. The present study was designed to evaluate the insulin sensitizing effects of peroxisomes proliferators activated receptor gamma (PPAR-γ) agonist on trace elements in obesity induced type 2 diabetes mellitus and correlate with serum visfatin. Wistar rats were categorized into five groups. Group I served as control; Group II fed on high fat diet (HFD); Group III fed on HFD and treated with rosiglitazone (3 mg/kg) for 7 days; Group IV were T2DM rats induce by HFD and low dose of streptozotocin (i.p. 35 mg/kg); Group V was T2DM rats treated with rosiglitazone (3 mg/kg) for 7 days. Serum and tissues electrolytes levels and renal, hepatic and cardiac tissues trace elements were estimated by flame photometer and atomic absorption spectroscopy. Serum visfatin was estimated by ELISA. Pearson correlations were analyzed among fasting blood glucose (FBG), serum visfatin and tissues trace elements. Results of the current study showed hyponatremia, hyperkalemia, hypomagnesemia and hypercalcemia in HFD and T2DM groups. HFD and T2DM also showed elevated copper and iron levels; however, zinc and selenium levels were decreased. Rosiglitazone treatment increased the insulin sensitization and altered these changes. A Strong association was observed among FBG, serum visfatin and trace elements levels of HFD and T2DM. Obesity and diabetes mellitus disturbed visfatin, electrolytes and trace elements homeostasis. Rosiglitazone treatment restored these changes. The results of the study could serve as a basis for further studies for the prevention of diabetic complications. Copyright © 2018 Elsevier Inc. All rights reserved.

Revision of the Australian Union-Jack wolf spiders, genus Tasmanicosa (Araneae, Lycosidae, Lycosinae).

PubMed

Framenau, Volker W; Baehr, Barbara C

2016-12-23

The Australian wolf spider (Lycosidae Sundevall, 1833) genus Tasmanicosa Roewer, 1959 with Lycosa tasmanica Hogg, 1905 as type species is revised to include 14 species: T. godeffroyi (L. Koch, 1865), comb. nov. (= Lycosa tasmanica Hogg, 1905, syn. nov.; = Lycosa zualella Strand, 1907, syn. nov.; = Lycosa woodwardi Simon, 1909, syn. nov.); T. fulgor sp. nov.; T. gilberta (Hogg, 1905) comb. nov.; T. harmsi sp. nov.; T. hughjackmani sp. nov.; T. kochorum sp. nov.; T. leuckartii (Thorell, 1870), comb. nov. (= Lycosa molyneuxi Hogg, 1905, syn. nov.); T. musgravei (McKay, 1974) comb. nov.; T. phyllis (Hogg, 1905) comb. nov. (= Lycosa stirlingae Hogg, 1905, syn. nov.); T. ramosa (L. Koch, 1877), comb. nov.; T. salmo sp. nov.; T. semicincta (L. Koch, 1877) comb. nov.; T. stella sp. nov.; and T. subrufa (Karsch, 1878) comb. nov. Within the Australian wolf spider fauna, the genus Tasmanicosa can be diagnosed by the distinct pattern of radiating light and dark lines forming a "Union-Jack" pattern on the carapace. Male pedipalp morphology identifies the genus as part of the subfamily Lycosinae Sundevall, 1833 due to the presence of a transverse tegular apophysis with dorsal groove guiding the embolus during copulation. However, genital morphology is variable and a synapomorphy based on male pedipalp or female epigyne morphology could not be identified. Members of Tasmanicosa are comparatively large spiders (body length ca. 12-30 mm), that build a shallow burrow, which is sometimes covered with a flimsy trapdoor. Species of Tasmanicosa are largely a Bassian faunal element with preference for open woodlands and/or floodplains, although some species can be found into the semi-arid Australian interior. Two Australian wolf spider species may represent Tasmanicosa based on their original descriptions, but due to immature types in combination with the somatic similarities of all Tasmanicosa species, cannot be identified with certainty. They are therefore considered nomina dubia: Lycosa excusor L. Koch, 1867 and Lycosa infensa L. Koch, 1877. The type species of Orthocosa Roewer, 1960 is transferred to Tasmanicosa; however, in order to prevent some non-Australian wolf spiders in the genus Orthocosa to be transferred into Tasmanicosa, which is considered endemic to Australia, we here place these species into more appropriate genera based on their original descriptions pending a future revision of these species: Arctosa ambigua Denis, 1947 comb. reval.; Alopecosa orophila (Thorell, 1887) comb. nov.; Hygrolycosa tokinagai Saito, 1936 comb. reval. Orthocosa sternomaculata (Mello-Leitão, 1943) is considered a junior synonym of Hogna birabeni (Mello-Leitão, 1943) comb. nov.

Hg-contaminated terrestrial spiders pose a potential risk to songbirds at Caddo Lake (Texas/Louisiana, USA).

PubMed

Gann, Gretchen L; Powell, Cleveland H; Chumchal, Matthew M; Drenner, Ray W

2015-02-01

Methylmercury (MeHg) is an environmental contaminant that can have adverse effects on wildlife. Because MeHg is produced by bacteria in aquatic ecosystems, studies of MeHg contamination of food webs historically have focused on aquatic organisms. However, recent studies have shown that terrestrial organisms such as songbirds can be contaminated with MeHg by feeding on MeHg-contaminated spiders. In the present study, the authors examined the risk that MeHg-contaminated terrestrial long-jawed orb weaver spiders (Tetragnatha sp.) pose to songbirds at Caddo Lake (Texas/Louisiana, USA). Methylmercury concentrations in spiders were significantly different in river, wetland, and open-water habitats. The authors calculated spider-based wildlife values (the minimum spider MeHg concentrations causing physiologically significant doses in consumers) to assess exposure risks for arachnivorous birds. Methylmercury concentrations in spiders exceeded wildlife values for Carolina chickadee (Poecile carolinensis) nestlings, with the highest risk in the river habitat. The present study indicates that MeHg concentrations in terrestrial spiders vary with habitat and can pose a threat to small-bodied nestling birds that consume large amounts of spiders at Caddo Lake. This MeHg threat to songbirds may not be unique to Caddo Lake and may extend throughout the southeastern United States. © 2014 SETAC.

Web orientation and prey resources for web-building spiders in eastern hemlock.

PubMed

Mallis, Rachael E; Rieske, Lynne K

2010-10-01

We examined the arthropod community on eastern hemlock, Tsuga canadensis (L.) Carr, in the context of its role in providing potential prey items for hemlock-associated web-weaving spiders. Using sticky traps simulating spider webs, we evaluated what prey items are available to web-weaving spiders in eastern hemlock based on web orientation (horizontal versus vertical) and cardinal direction. We found that the overwhelming majority (>70%) of prey items available to spiders in hemlock canopies were Diptera. Psocoptera, Hymenoptera, and Hemiptera comprised most of the remaining potential prey. A significant direction × orientation interaction, and greater trap capture in some direction-orientation combinations, suggests that spiders might locate their webs in eastern hemlock canopies for thermoregulatory purposes, ultimately optimizing prey capture. We also evaluated these findings in the context of hemlock infestation by the invasive hemlock woolly adelgid, Adelges tsugae Annand. The adelgid is a sedentary insect with a mobile crawler stage that provides a readily available, easily obtained food source for predators in hemlock canopies. However, an abundance of alternative prey will affect within canopy spider distribution and the potential intensity with which spiders consume these prey. Understanding the response of spiders to potential prey availability is essential to understanding the trophic interactions involving these predators and their potential for influencing herbivore populations.

Japanese monkeys (Macaca fuscata) quickly detect snakes but not spiders: Evolutionary origins of fear-relevant animals.

PubMed

Kawai, Nobuyuki; Koda, Hiroki

2016-08-01

Humans quickly detect the presence of evolutionary threats through visual perception. Many theorists have considered humans to be predisposed to respond to both snakes and spiders as evolutionarily fear-relevant stimuli. Evidence supports that human adults, children, and snake-naive monkeys all detect pictures of snakes among pictures of flowers more quickly than vice versa, but recent neurophysiological and behavioral studies suggest that spiders may, in fact, be processed similarly to nonthreat animals. The evidence of quick detection and rapid fear learning by primates is limited to snakes, and no such evidence exists for spiders, suggesting qualitative differences between fear of snakes and fear of spiders. Here, we show that snake-naive Japanese monkeys detect a single snake picture among 8 nonthreat animal pictures (koala) more quickly than vice versa; however, no such difference in detection was observed between spiders and pleasant animals. These robust differences between snakes and spiders are the most convincing evidence that the primate visual system is predisposed to pay attention to snakes but not spiders. These findings suggest that attentional bias toward snakes has an evolutionary basis but that bias toward spiders is more due to top-down, conceptually driven effects of emotion on attention capture. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Analysis of transcriptomes of three orb-web spider species reveals gene profiles involved in silk and toxin.

PubMed

Zhao, Ying-Jun; Zeng, Yan; Chen, Lei; Dong, Yang; Wang, Wen

2014-12-01

As an ancient arthropod with a history of 390 million years, spiders evolved numerous morphological forms resulting from adaptation to different environments. The venom and silk of spiders, which have promising commercial applications in agriculture, medicine and engineering fields, are of special interests to researchers. However, little is known about their genomic components, which hinders not only understanding spider biology but also utilizing their valuable genes. Here we report on deep sequenced and de novo assembled transcriptomes of three orb-web spider species, Gasteracantha arcuata, Nasoonaria sinensis and Gasteracantha hasselti which are distributed in tropical forests of south China. With Illumina paired-end RNA-seq technology, 54 871, 101 855 and 75 455 unigenes for the three spider species were obtained, respectively, among which 9 300, 10 001 and 10 494 unique genes are annotated, respectively. From these annotated unigenes, we comprehensively analyzed silk and toxin gene components and structures for the three spider species. Our study provides valuable transcriptome data for three spider species which previously lacked any genetic/genomic data. The results have laid the first fundamental genomic basis for exploiting gene resources from these spiders. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Photoluminescent properties of spider silk coated with Eu-doped nanoceria

NASA Astrophysics Data System (ADS)

Dmitrović, Svetlana; Nikolić, Marko G.; Jelenković, Branislav; Prekajski, Marija; Rabasović, Mihailo; Zarubica, Aleksandra; Branković, Goran; Matović, Branko

2017-02-01

Spider dragline silk was coated with pure as well as Eu-doped ceria nanopowders at the room temperature. The treatment was done by immersion of the spider silk mesh into aqueous solutions of cerium nitrate (Ce(NO3)3) and ammonium hydroxide (NH4OH). Depending on the relationship between Ce3+ ion and ammonium hydroxide concentration, coated fibers exhibited a different thickness. Obtained materials were studied by means of FESEM. It was found that ceria nanoparticles of average size of 3 nm were coated along spider thread. X-ray diffraction (XRD) and selected-area electron diffraction (SAED) confirmed crystal nature of nanoparticle coating of spider silk. By using Williamson-Hall plots, crystallite size and strain were estimated. EDS measurement confirmed the presence of Eu in spider-Eu-doped ceria composite, and according to FTIR analysis, the interaction between CeO2 and spider silk was proposed. The morphology of obtained composite was observed by TEM. The photoluminescence emission spectra of spider silk coated with Eu-doped ceria were measured with two different excitations of 385 and 466 nm. The two-photon excited auto-fluorescence of spider silk coated with Eu-doped ceria was detected using a nonlinear laser scanning microscope. Obtained composite has a potential as a fluorescent labeling material in diverse applications.

Are Temperate Canopy Spiders Tree-Species Specific?

PubMed Central

Mupepele, Anne-Christine; Müller, Tobias; Dittrich, Marcus; Floren, Andreas

2014-01-01

Arboreal spiders in deciduous and coniferous trees were investigated on their distribution and diversity. Insecticidal knock-down was used to comprehensively sample spiders from 175 trees from 2001 to 2003 in the Białowieża forest and three remote forests in Poland. We identified 140 species from 9273 adult spiders. Spider communities were distinguished between deciduous and coniferous trees. The richest fauna was collected from Quercus where beta diversity was also highest. A tree-species-specific pattern was clearly observed for Alnus, Carpinus, Picea and Pinus trees and also for those tree species that were fogged in only four or three replicates, namely Betula and Populus. This hitherto unrecognised association was mainly due to the community composition of common species identified in a Dufrene-Legendre indicator species analysis. It was not caused by spatial or temporal autocorrelation. Explaining tree-species specificity for generalist predators like spiders is difficult and has to involve physical and ecological tree parameters like linkage with the abundance of prey species. However, neither did we find a consistent correlation of prey group abundances with spiders nor could differences in spider guild composition explain the observed pattern. Our results hint towards the importance of deterministic mechanisms structuring communities of generalist canopy spiders although the casual relationship is not yet understood. PMID:24586251

Are temperate canopy spiders tree-species specific?

PubMed

Mupepele, Anne-Christine; Müller, Tobias; Dittrich, Marcus; Floren, Andreas

2014-01-01

Arboreal spiders in deciduous and coniferous trees were investigated on their distribution and diversity. Insecticidal knock-down was used to comprehensively sample spiders from 175 trees from 2001 to 2003 in the Białowieża forest and three remote forests in Poland. We identified 140 species from 9273 adult spiders. Spider communities were distinguished between deciduous and coniferous trees. The richest fauna was collected from Quercus where beta diversity was also highest. A tree-species-specific pattern was clearly observed for Alnus, Carpinus, Picea and Pinus trees and also for those tree species that were fogged in only four or three replicates, namely Betula and Populus. This hitherto unrecognised association was mainly due to the community composition of common species identified in a Dufrene-Legendre indicator species analysis. It was not caused by spatial or temporal autocorrelation. Explaining tree-species specificity for generalist predators like spiders is difficult and has to involve physical and ecological tree parameters like linkage with the abundance of prey species. However, neither did we find a consistent correlation of prey group abundances with spiders nor could differences in spider guild composition explain the observed pattern. Our results hint towards the importance of deterministic mechanisms structuring communities of generalist canopy spiders although the casual relationship is not yet understood.

Neural correlation of successful cognitive behaviour therapy for spider phobia: a magnetoencephalography study.

PubMed

Wright, Barry; Alderson-Day, Ben; Prendergast, Garreth; Kennedy, Juliette; Bennett, Sophie; Docherty, Mary; Whitton, Clare; Manea, Laura; Gouws, Andre; Tomlinson, Heather; Green, Gary

2013-12-30

Cognitive behavioural therapy (CBT) can be an effective treatment for spider phobia, but the underlying neural correlates of therapeutic change are yet to be specified. The present study used magnetoencephalography (MEG) to study responses within the first half second, to phobogenic stimuli in a group of individuals with spider phobia prior to treatment (n=12) and then in nine of them following successful CBT (where they could touch and manage live large common house spiders) at least 9 months later. We also compared responses to a group of age-matched healthy control participants (n=11). Participants viewed static photographs of real spiders, other fear-inducing images (e.g. snakes, sharks) and neutral stimuli (e.g. kittens). Beamforming methods were used to localise sources of significant power changes in response to stimuli. Prior to treatment, participants with spider phobia showed a significant maximum response in the right frontal pole when viewing images of real spiders specifically. No significant frontal response was observed for either control participants or participants with spider phobia post-treatment. In addition, participants' subjective ratings of spider stimuli significantly predicted peak responses in right frontal regions. The implications for understanding brain-based effects of cognitive therapies are discussed. © 2013 Published by Elsevier Ireland Ltd.

Major and trace elements in igneous rocks from Apollo 15.

NASA Technical Reports Server (NTRS)

Helmke, P. A.; Blanchard, D. P.; Haskin, L. A.; Telander, K.; Weiss, C.; Jacobs, J. W.

1973-01-01

The concentrations of major and trace elements have been determined in igneous rocks from Apollo 15. All materials analyzed have typical depletions of Eu except for minerals separated from sample 15085. Four samples have concentrations of trace elements that are similar to those of KREEP. The samples of mare basalt from Apollo 15 have higher concentrations of FeO, MgO, Mn, and Cr and lower concentrations of CaO, Na2O, K2O, and rare-earth elements (REE) as compared to the samples of mare basalt from Apollos 11, 12, and 14. The samples can be divided into two groups on the basis of their normative compositions. One group is quartz normative and has low concentrations of FeO while the other is olivine normative and has high concentrations of FeO. The trace element data indicate that the samples of olivine normative basalt could be from different portions of a single lava flow.

Trace elements in coal. Environmental and health significance

USGS Publications Warehouse

Finkelman, R.B.

1999-01-01

Trace elements can have profound adverse effects on the health of people burning coal in homes or living near coal deposits, coal mines, and coal- burning power plants. Trace elements such as arsenic emitted from coal- burning power plants in Europe and Asia have been shown to cause severe health problems. Perhaps the most widespread health problems are caused by domestic coal combustion in developing countries where millions of people suffer from fluorosis and thousands from arsenism. Better knowledge of coal quality characteristics may help to reduce some of these health problems. For example, information on concentrations and distributions of potentially toxic elements in coal may help delineate areas of a coal deposit to be avoided. Information on the modes of occurrence of these elements and the textural relations of the minerals in coal may help to predict the behavior of the potentially toxic trace metals during coal cleaning, combustion, weathering, and leaching.

Trace elements study of high purity nanocrystalline silicon carbide (3C-SiC) using k0-INAA method

NASA Astrophysics Data System (ADS)

Huseynov, Elchin; Jazbec, Anze

2017-07-01

Silicon carbide (3C-SiC) nanoparticles have been irradiated by neutron flux (2×1013 n·cm-2·s-1) at TRIGA Mark II type research reactor. After neutron irradiation, the radioisotopes of trace elements in the nanocrystalline 3C-SiC were studied as time functions. The identification of isotopes which significantly increased the activity of the samples as a result of neutron radiation was carried out. Nanocrystalline 3C-SiC are synthesized by standard laser technique and the purity of samples was determined by the k0-based Instrumental Neutron Activation Analysis (k0-INAA) method. Trace elements concentration in the 3C-SiC nanoparticles were determined by the radionuclides of appropriate elements. The trace element isotopes concentration have been calculated in percentage according to k0-INAA method.

Concentrations of selected trace elements in mineral and spring bottled waters on the Serbian market.

PubMed

Ristić, M; Popović, I; Pocajt, V; Antanasijević, D; Perić-Grujić, A

2011-01-01

Eight selected trace elements, which are generally included in regulations, were analyzed in 23 types of bottled waters. Ten mineral and seven spring bottled waters were from the Serbian market and six mineral bottled waters were obtained in different EU countries. For the purpose of comparison, selected tap waters were also analyzed. Inductively coupled plasma mass spectrometry (ICP-MS) was used for the analysis of trace elements (arsenic, cadmium, copper, manganese, nickel, lead and antimony). Results were compared with the Serbian regulations for bottled water, EU regulations and guideline values set by the World Health Organization for drinking water. With few exceptions, the trace element levels of most bottled waters were below the guideline values. However, a higher content of antimony was observed in waters from polyethylene terephthalate (PET) containers, indicating a potential leaching of this element from the plastic packaging.

Information Summary, Area of Concern: Grand Calumet River, Indiana

DTIC Science & Technology

1991-03-01

Indiana Harbor and Adjacent Lake Michigan (Source Rl, Table 4) 10 Concentrations of 26 Major, Minor and Trace Elements in Sediments from Indiana Harbor...2 Dec 84 (Source R39, Table 2) 68 Concentrations of Major, Minor , and Trace Elements in Fish and Crayfish from Indiana Harbor and Adjacent Lake...Table 21b) 71 Catch per Unit Effort in Crayfish Traps (Source Rl, Table 21c) 72 Concentratiors of Major, Minor , and Trace Elements in Periphyton and

Raccoons (Procyon lotor) as Sentinels of Trace Element Contamination and Physiological Effects of Exposure to Coal Fly Ash

DOE PAGES

Hernandez, Felipe; Oldenkamp, Ricki E.; Webster, Sarah; ...

2016-12-08

Anthropogenic pollutants disrupt global biodiversity, and terrestrial sentinels of pollution can provide a warning system for ecosystem-wide contamination. This study sought to assess whether raccoons (Procyon lotor) are sentinels of local exposure to trace element contaminants at a coal fly ash site and whether exposure resulted in health impairment or changes in the intestinal helminth communities. We compared trace element accumulation and the impact on health responses and intestinal helminth communities of raccoons inhabiting contaminated and reference sites of the U.S. Department of Energy’s Savannah River Site (South Carolina, USA). Data on morphometry, hematology, histopathology, helminth community and abundance, andmore » liver trace element burdens were collected from 15 raccoons captured adjacent to a coal fly ash basin and 11 raccoons from a comparable uncontaminated site nearby. Of eight trace elements analyzed, Cu, As, Se, and Pb were elevated in raccoons from the contaminated site. Raccoons from the contaminated site harbored higher helminth abundance than animals from the reference site and that abundance was positively associated with increased Cu concentrations. While we found changes in hematology associated with increased Se exposure, we did not find physiological or histological changes associated with higher levels of contaminants. Our results suggest that raccoons and their intestinal helminths act as sentinels of trace elements in the environment associated with coal fly ash contamination.« less

Seasonal Cyclicity in Trace Elements and Stable Isotopes of Modern Horse Enamel.

PubMed

de Winter, Niels J; Snoeck, Christophe; Claeys, Philippe

2016-01-01

The study of stable isotopes in fossil bioapatite has yielded useful results and has shown that bioapatites are able to faithfully record paleo-environmental and paleo-climatic parameters from archeological to geological timescales. In an effort to establish new proxies for the study of bioapatites, intra-tooth records of enamel carbonate stable isotope ratios from a modern horse are compared with trace element profiles measured using laboratory micro X-Ray Fluorescence scanning. Using known patterns of tooth eruption and the relationship between stable oxygen isotopes and local temperature seasonality, an age model is constructed that links records from six cheek upper right teeth from the second premolar to the third molar. When plotted on this age model, the trace element ratios from horse tooth enamel show a seasonal pattern with a small shift in phase compared to stable oxygen isotope ratios. While stable oxygen and carbon isotopes in tooth enamel are forced respectively by the state of the hydrological cycle and the animal's diet, we argue that the seasonal signal in trace elements reflects seasonal changes in dust intake and diet of the animal. The latter explanation is in agreement with seasonal changes observed in carbon isotopes of the same teeth. This external forcing of trace element composition in mammal tooth enamel implies that trace element ratios may be used as proxies for seasonal changes in paleo-environment and paleo-diet.

Seasonal Cyclicity in Trace Elements and Stable Isotopes of Modern Horse Enamel

PubMed Central

Snoeck, Christophe; Claeys, Philippe

2016-01-01

The study of stable isotopes in fossil bioapatite has yielded useful results and has shown that bioapatites are able to faithfully record paleo-environmental and paleo-climatic parameters from archeological to geological timescales. In an effort to establish new proxies for the study of bioapatites, intra-tooth records of enamel carbonate stable isotope ratios from a modern horse are compared with trace element profiles measured using laboratory micro X-Ray Fluorescence scanning. Using known patterns of tooth eruption and the relationship between stable oxygen isotopes and local temperature seasonality, an age model is constructed that links records from six cheek upper right teeth from the second premolar to the third molar. When plotted on this age model, the trace element ratios from horse tooth enamel show a seasonal pattern with a small shift in phase compared to stable oxygen isotope ratios. While stable oxygen and carbon isotopes in tooth enamel are forced respectively by the state of the hydrological cycle and the animal’s diet, we argue that the seasonal signal in trace elements reflects seasonal changes in dust intake and diet of the animal. The latter explanation is in agreement with seasonal changes observed in carbon isotopes of the same teeth. This external forcing of trace element composition in mammal tooth enamel implies that trace element ratios may be used as proxies for seasonal changes in paleo-environment and paleo-diet. PMID:27875538

Connecting pigment composition and dissolved trace elements to phytoplankton population in the southern Benguela Upwelling zone (St. Helena Bay)

NASA Astrophysics Data System (ADS)

Das, Supriyo Kumar; Routh, Joyanto; Roychoudhury, Alakendra N.; Veldhuis, Marcel J. W.; Ismail, Hassan E.

2017-12-01

Rich in upwelled nutrients, the Southern Benguela is one of the most productive ecosystems in the world ocean. However, despite its ecological significance the role of trace elements influencing phytoplankton population in the Southern Benguela Upwelling System (SBUS) has not been thoroughly investigated. Here, we report pigment composition, macronutrients (nitrate, phosphate and silicate) and concentrations of dissolved Cd, Co, Fe and Zn during late austral summer and winter seasons in 2004 to understand the relationship between the selected trace elements and phytoplankton biomass in St. Helena Bay (SHB), which falls within the southern boundary of the SBUS. Chlorophyll a concentrations indicate higher phytoplankton biomass associated with high primary production during late summer in SHB where high diatom population is inferred from the presence of fucoxanthin. Diminished phytoplankton biomass and a shift from diatoms to dinoflagellates as the dominant phytoplankton taxa are indicated by diagnostic pigments during late winter. Dissolved trace elements (Cd, Co and Zn) and macronutrients play a significant role in phytoplankton biomass, and their distribution is affected by biological uptake and export of trace elements. Continuous uptake of Zn by diatoms may cause an onset of Zn depletion leading to a period of extended diatom proliferation during late summer. Furthermore, the transition from diatom to dinoflagellate dominated phytoplankton population is most likely facilitated by depletion of trace elements (Cd and Co) in the water column.

Raccoons (Procyon lotor) as Sentinels of Trace Element Contamination and Physiological Effects of Exposure to Coal Fly Ash

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

Hernandez, Felipe; Oldenkamp, Ricki E.; Webster, Sarah

Anthropogenic pollutants disrupt global biodiversity, and terrestrial sentinels of pollution can provide a warning system for ecosystem-wide contamination. This study sought to assess whether raccoons (Procyon lotor) are sentinels of local exposure to trace element contaminants at a coal fly ash site and whether exposure resulted in health impairment or changes in the intestinal helminth communities. We compared trace element accumulation and the impact on health responses and intestinal helminth communities of raccoons inhabiting contaminated and reference sites of the U.S. Department of Energy’s Savannah River Site (South Carolina, USA). Data on morphometry, hematology, histopathology, helminth community and abundance, andmore » liver trace element burdens were collected from 15 raccoons captured adjacent to a coal fly ash basin and 11 raccoons from a comparable uncontaminated site nearby. Of eight trace elements analyzed, Cu, As, Se, and Pb were elevated in raccoons from the contaminated site. Raccoons from the contaminated site harbored higher helminth abundance than animals from the reference site and that abundance was positively associated with increased Cu concentrations. While we found changes in hematology associated with increased Se exposure, we did not find physiological or histological changes associated with higher levels of contaminants. Our results suggest that raccoons and their intestinal helminths act as sentinels of trace elements in the environment associated with coal fly ash contamination.« less

[Determination of trace heavy metal elements in cortex Phellodendron chinense by ICP-MS after microwave-assisted digestion].

PubMed

Kou, Xing-Ming; Xu, Min; Gu, Yong-Zuo

2007-06-01

An inductively coupled plasma mass spectrometry (ICP-MS) for determination of the contents of 8 trace heavy metal elements in cortex Phellodendron chinense after microwave-assisted digestion of the sample has been developed. The accuracy of the method was evaluated by the analysis of corresponding trace heavy metal elements in standard reference materials (GBW 07604 and GBW 07605). By applying the proposed method, the contents of 8 trace heavy metal elements in cortex Phellodendron chinense cultivated in different areas (in Bazhong, Yibin and Yingjing, respectively) of Sichuan and different growth period (6, 8 and 10 years of samples from Yingjing) were determined. The relative standard deviation (RSD) is in the range of 3.2%-17.8% and the recoveries of standard addition are in the range of 70%-120%. The results of the study indicate that the proposed method has the advantages of simplicity, speediness and sensitivity. It is suitable for the determination of the contents of 8 trace heavy metal elements in cortex Phellodendron chinense. The results also show that the concentrations of 4 harmful trace heavy metal elements As, Cd, Hg and Pb in cortex Phellodendron chinense are all lower than the limits of Chinese Pharmacopoeia and Green Trade Standard for Importing and Exporting Medicinal Plant and Preparation. Therefore, the cortex Phellodendron chinense is fit for use as medicine and export.

A comparison of spider communities in Bt and non-Bt rice fields.

PubMed

Lee, Sue Yeon; Kim, Seung Tae; Jung, Jong Kook; Lee, Joon-Ho

2014-06-01

To assess the potential adverse effects of a Bt rice line (Japonica rice cultivar, Nakdong) expressing a synthetic cry1Ac1 gene, C7-1-9-1-B, which was highly active against all larval stages of Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Crambidae), we investigated the community structure of spiders in Bt and non-Bt rice fields during the rice-growing season in 2007 and 2008 in Chungcheongnam-do, Korea. Spiders were surveyed with a sweep net and suction device. Suction sampling captured more spiders, measured in terms of species level and abundance, than sweeping. Araneidae and Thomisidae were captured more by sweeping, and certain species were captured only by sweeping. These findings show that both suction and sweep sampling methods should be used because these methods are most likely complementary. In total, 29 species in 23 genera and nine families were identified from the 4,937 spiders collected, and both Bt and non-Bt rice fields showed a typical Korean spider assemblage. The temporal patterns of spider species richness and spider abundance were very similar between Bt and non-Bt rice, although significant differences in species richness were observed on a few occasions. Overall, spider community structure, including diversity, the dominant species, and abundance did not differ between Bt and non-Bt rice. The results of the study indicated that the transgenic Cry1Ac rice lines tested in this study had no adverse effects on the spider community structure of the rice fields.

Low-Tech, Pilot Scale Purification of a Recombinant Spider Silk Protein Analog from Tobacco Leaves.

PubMed

Heppner, René; Weichert, Nicola; Schierhorn, Angelika; Conrad, Udo; Pietzsch, Markus

2016-10-09

Spider dragline is used by many members of the Araneae family not only as a proteinogenic safety thread but also for web construction. Spider dragline has been shown to possess high tensile strength in combination with elastic behavior. This high tensile strength can be attributed to the presence of antiparallel β-sheets within the thread; these antiparallel β-sheets are why the protein is classified as a silk. Due to the properties of spider silk and its technical and medical uses, including its use as a suture material and as a scaffold for tissue regeneration, spider dragline is a focus of the biotechnology industry. The production of sufficient amounts of spider silk is challenging, as it is difficult to produce large quantities of fibers because of the cannibalistic behavior of spiders and their large spatial requirements. In recent years, the heterologous expression of genes coding for spider silk analogs in various hosts, including plants such as Nicotiana tabacum , has been established. We developed a simple and scalable method for the purification of a recombinant spider silk protein elastin-like peptide fusion protein (Q-/K-MaSp1-100× ELP) after heterologous production in tobacco leaves involving heat and acetone precipitation. Further purification was performed using centrifugal Inverse Transition Cycling (cITC). Up to 400 mg of highly pure spider silk protein derivatives can be isolated from six kilograms of tobacco leaves, which is the highest amount of silk protein derivatives purified from plants thus far.

Spider Transcriptomes Identify Ancient Large-Scale Gene Duplication Event Potentially Important in Silk Gland Evolution.

PubMed

Clarke, Thomas H; Garb, Jessica E; Hayashi, Cheryl Y; Arensburger, Peter; Ayoub, Nadia A

2015-06-08

The evolution of specialized tissues with novel functions, such as the silk synthesizing glands in spiders, is likely an influential driver of adaptive success. Large-scale gene duplication events and subsequent paralog divergence are thought to be required for generating evolutionary novelty. Such an event has been proposed for spiders, but not tested. We de novo assembled transcriptomes from three cobweb weaving spider species. Based on phylogenetic analyses of gene families with representatives from each of the three species, we found numerous duplication events indicative of a whole genome or segmental duplication. We estimated the age of the gene duplications relative to several speciation events within spiders and arachnids and found that the duplications likely occurred after the divergence of scorpions (order Scorpionida) and spiders (order Araneae), but before the divergence of the spider suborders Mygalomorphae and Araneomorphae, near the evolutionary origin of spider silk glands. Transcripts that are expressed exclusively or primarily within black widow silk glands are more likely to have a paralog descended from the ancient duplication event and have elevated amino acid replacement rates compared with other transcripts. Thus, an ancient large-scale gene duplication event within the spider lineage was likely an important source of molecular novelty during the evolution of silk gland-specific expression. This duplication event may have provided genetic material for subsequent silk gland diversification in the true spiders (Araneomorphae). © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Hemocyanin gene family evolution in spiders (Araneae), with implications for phylogenetic relationships and divergence times in the infraorder Mygalomorphae.

PubMed

Starrett, James; Hedin, Marshal; Ayoub, Nadia; Hayashi, Cheryl Y

2013-07-25

Hemocyanins are multimeric copper-containing hemolymph proteins involved in oxygen binding and transport in all major arthropod lineages. Most arachnids have seven primary subunits (encoded by paralogous genes a-g), which combine to form a 24-mer (4×6) quaternary structure. Within some spider lineages, however, hemocyanin evolution has been a dynamic process with extensive paralog duplication and loss. We have obtained hemocyanin gene sequences from numerous representatives of the spider infraorders Mygalomorphae and Araneomorphae in order to infer the evolution of the hemocyanin gene family and estimate spider relationships using these conserved loci. Our hemocyanin gene tree is largely consistent with the previous hypotheses of paralog relationships based on immunological studies, but reveals some discrepancies in which paralog types have been lost or duplicated in specific spider lineages. Analyses of concatenated hemocyanin sequences resolved deep nodes in the spider phylogeny and recovered a number of clades that are supported by other molecular studies, particularly for mygalomorph taxa. The concatenated data set is also used to estimate dates of higher-level spider divergences and suggests that the diversification of extant mygalomorphs preceded that of extant araneomorphs. Spiders are diverse in behavior and respiratory morphology, and our results are beneficial for comparative analyses of spider respiration. Lastly, the conserved hemocyanin sequences allow for the inference of spider relationships and ancient divergence dates. Copyright © 2013 Elsevier B.V. All rights reserved.

Predator size and the suitability of a common prey.

PubMed

Erickson, Kristin S; Morse, D H

1997-02-01

 Although a predator's mass should influence the suitability of its prey, this subject has received little direct attention. We studied the capture and processing of an abundant syrphid fly Toxomerus marginatus (c. 4 mg) by 0.6- to 40-mg juvenile crab spiders Misumena vatia (Thomisidae) to determine how profitability, relative profitability (profitability/predator mass), overall gain in mass, and relative gain in mass differed with predator mass, and whether foraging changed concurrently. In multi-prey experiments, the smallest successful spiders (0.6-3.0 mg) extracted less mass from flies, and did so more slowly, than large spiders. This gain was proportionately similar to that of 10- to 40-mg spiders with access to many Toxomerus. However, many small spiders failed to capture flies. When we gave spiders only a single Toxomerus, the smallest ones again extracted mass more slowly than the large ones and increased in mass less than the large ones, but increased in mass proportionately more than large ones. Relative gain in mass from a single prey decreased with increasing spider mass. Spiders larger than 10 mg all extracted similar amounts of mass from a single Toxomerus at similar rates, but varied in time spent between captures. Thus, Toxomerus changes with spider mass from a large, hard-to-capture bonanza to a small, easy-to-capture item of low per capita value. However, Toxomerus is common enough that large spiders can capture it en masse, thereby compensating for its decline in per capita value.

Bat predation by spiders.

PubMed

Nyffeler, Martin; Knörnschild, Mirjam

2013-01-01

In this paper more than 50 incidences of bats being captured by spiders are reviewed. Bat-catching spiders have been reported from virtually every continent with the exception of Antarctica (≈ 90% of the incidences occurring in the warmer areas of the globe between latitude 30° N and 30° S). Most reports refer to the Neotropics (42% of observed incidences), Asia (28.8%), and Australia-Papua New Guinea (13.5%). Bat-catching spiders belong to the mygalomorph family Theraphosidae and the araneomorph families Nephilidae, Araneidae, and Sparassidae. In addition to this, an attack attempt by a large araneomorph hunting spider of the family Pisauridae on an immature bat was witnessed. Eighty-eight percent of the reported incidences of bat catches were attributable to web-building spiders and 12% to hunting spiders. Large tropical orb-weavers of the genera Nephila and Eriophora in particular have been observed catching bats in their huge, strong orb-webs (of up to 1.5 m diameter). The majority of identifiable captured bats were small aerial insectivorous bats, belonging to the families Vespertilionidae (64%) and Emballonuridae (22%) and usually being among the most common bat species in their respective geographic area. While in some instances bats entangled in spider webs may have died of exhaustion, starvation, dehydration, and/or hyperthermia (i.e., non-predation death), there were numerous other instances where spiders were seen actively attacking, killing, and eating the captured bats (i.e., predation). This evidence suggests that spider predation on flying vertebrates is more widespread than previously assumed.

Bat Predation by Spiders

PubMed Central

Nyffeler, Martin; Knörnschild, Mirjam

2013-01-01

In this paper more than 50 incidences of bats being captured by spiders are reviewed. Bat-catching spiders have been reported from virtually every continent with the exception of Antarctica (∼90% of the incidences occurring in the warmer areas of the globe between latitude 30° N and 30° S). Most reports refer to the Neotropics (42% of observed incidences), Asia (28.8%), and Australia-Papua New Guinea (13.5%). Bat-catching spiders belong to the mygalomorph family Theraphosidae and the araneomorph families Nephilidae, Araneidae, and Sparassidae. In addition to this, an attack attempt by a large araneomorph hunting spider of the family Pisauridae on an immature bat was witnessed. Eighty-eight percent of the reported incidences of bat catches were attributable to web-building spiders and 12% to hunting spiders. Large tropical orb-weavers of the genera Nephila and Eriophora in particular have been observed catching bats in their huge, strong orb-webs (of up to 1.5 m diameter). The majority of identifiable captured bats were small aerial insectivorous bats, belonging to the families Vespertilionidae (64%) and Emballonuridae (22%) and usually being among the most common bat species in their respective geographic area. While in some instances bats entangled in spider webs may have died of exhaustion, starvation, dehydration, and/or hyperthermia (i.e., non-predation death), there were numerous other instances where spiders were seen actively attacking, killing, and eating the captured bats (i.e., predation). This evidence suggests that spider predation on flying vertebrates is more widespread than previously assumed. PMID:23516436

But what about the Empress of Racnoss? The allocation of attention to spiders and Doctor Who in a visual search task is predicted by fear and expertise.

PubMed

Purkis, Helena M; Lester, Kathryn J; Field, Andy P

2011-12-01

If there is a spider in the room, then the spider phobic in your group is most likely to point it out to you. This phenomenon is believed to arise because our attentional systems are hardwired to attend to threat in our environment, and, to a spider phobic, spiders are threatening. However, an alternative explanation is simply that attention is quickly drawn to the stimulus of most personal relevance in the environment. Our research examined whether positive stimuli with no biological or evolutionary relevance could be allocated preferential attention. We compared attention to pictures of spiders with pictures from the TV program Doctor Who, for people who varied in both their love of Doctor Who and their fear of spiders. We found a double dissociation: interference from spider and Doctor-Who-related images in a visual search task was predicted by spider fear and Doctor Who expertise, respectively. As such, allocation of attention reflected the personal relevance of the images rather than their threat content. The attentional system believed to have a causal role in anxiety disorders is therefore likely to be a general system that responds not to threat but to stimulus relevance; hence, nonevolutionary images, such as those from Doctor Who, captured attention as quickly as fear-relevant spider images. Where this leaves the Empress of Racnoss, we are unsure. (c) 2011 APA, all rights reserved.

Less is More: Neural Activity During Very Brief and Clearly Visible Exposure to Phobic Stimuli

PubMed Central

Siegel, Paul; Warren, Richard; Wang, Zhishun; Yang, Jie; Cohen, Don; Anderson, Jason F.; Murray, Lilly; Peterson, Bradley S.

2017-01-01

Research on automatic processes in emotion has focused almost exclusively on the provocation of fear responses. We have shown, in contrast, that the repeated presentation of masked feared images reduces avoidance of a live tarantula by spider-phobic participants. We investigated the neural basis for these adaptive effects of masked exposure. We identified 21 spider-phobic and 21 control participants using a psychiatric interview, fear questionnaire, and approach behavior towards a live tarantula. They received each of three conditions: (1) very brief exposure (VBE) to masked images of spiders; (2) clearly visible exposure (CVE) to spiders; and (3) masked images of flowers (control). Only VBE to masked spiders generated neural activity more strongly in phobic than in control participants, within subcortical fear, attention, higher-order language, and vision systems. Counter-intuitively, CVE to the same spiders generated stronger neural activity in control rather than phobic participants within these and other systems. VBE activated regions that support fear processing in phobic participants without causing them to experience fear consciously. CVE, by contrast, deactivated regions supporting fear regulation and caused phobic participants to experience fear. Activations by CVE to spiders correlated with fear ratings - explicit fear. Activations by VBE to masked spiders correlated with color-naming interference of spider words – implicit fear. These multiple dissociations between the effects of VBE and CVE to spiders suggest that limiting awareness of exposure to phobic stimuli through visual masking paradoxically facilitates their processing, while simultaneously minimizing the experience of fear. PMID:28165171

Trace element geochemistry of Archean volcanic rocks

NASA Technical Reports Server (NTRS)

Jahn, B.-M.; Shih, C.-Y.; Murthy, V. R.

1974-01-01

The K, Rb, Sr, Ba and rare-earth-element contents of some Archean volcanic rocks from the Vermilion greenstone belt, northeast Minnesota, were determined by the isotopic dilution method. The characteristics of trace element abundances, supported by the field occurrences and major element chemistry, suggest that these volcanic rocks were formed in an ancient island arc system.

Ultra-Sensitive Elemental Analysis Using Plasmas 7.Application to Criminal Investigation

NASA Astrophysics Data System (ADS)

Suzuki, Yasuhiro

This paper describes the application of trace elemental analysis using ICP-AES and ICP-MS to criminal investigation. The comparison of trace elements, such as Rb, Sr, Zr, and so on, is effective for the forensic discrimination of glass fragments, which can be important physical evidence for connecting a suspect to a crime scene or to a victim. This procedure can be applied also to lead shotgun pellets by the removal of matrix lead as the sulfate precipitate after the dissolution of a pellet sample. The determination of a toxic element in bio-logical samples is required to prove that a victim ingested this element. Arsenous acids produced in Japan, China, Germany and Switzerland show characteristic patterns of trace elements characteristic to each country.

Al-26, Pu-244, Ti-50, REE, and trace element abundances in hibonite grains from CM and CV meteorites

NASA Technical Reports Server (NTRS)

Fahey, A. J.; Mckeegan, K. D.; Zinner, E.; Goswami, J. N.

1987-01-01

Hibonites from the CM meteorites Murchison, Murray, and Cold Bokkeveld, and hibonites and Ti-rich pyroxene from the CV chondrite Allende are studied. Electron microprobe measurements of major element concentrations and track and ion probe measurements of Mg and Ti isotopic ratios, rare earth elements (REEs), and trace element abundances are analyzed. Correlations between isotopic anomalies in Ti, Al-26, Pu-244, and Mg-26(asterisk) are examined. Ti isotopic anomalies are compared with REE and trace element abundance patterns. Reasons for the lack of Al-26 in the hibonites are investigated and discussed. It is observed that there is no correlation between the Ti isotopic compositions, and the presence of Mg-26(asterisk), Pu-244, and REE and trace element patterns in individual hibonite samples. The data reveal that hibonites are not interstellar dust grains but formed on a short time scale and in localized regions of the early solar system.

Trace element partitioning during the retorting of Julia Creek oil shale

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

Patterson, J.H.; Dale, L.S.; Chapman, J.f.

1987-05-01

A bulk sample of oil shale from the Julia Creek deposit in Queensland was retorted under Fischer assay conditions at temperatures ranging from 250 to 550 /sup 0/C. The distributions of the trace elements detected in the shale oil and retort water were determined at each temperature. Oil distillation commenced at 300 /sup 0/C and was essentially complete at 500 /sup 0/C. A number of trace elements were progressively mobilized with increasing retort temperature up to 450 /sup 0/C. The following trace elements partitioned mainly to the oil: vanadium, arsenic, selenium, iron, nickel, titanium, copper, cobalt, and aluminum. Elements thatmore » also partitioned to the retort waters included arsenic, selenium, chlorine, and bromine. Element mobilization is considered to be caused by the volatilization of organometallic compounds, sulfide minerals, and sodium halides present in the oil shale. The results have important implications for shale oil refining and for the disposal of retort waters. 22 references, 5 tables.« less

Phytostabilization of semiarid soils residually contaminated with trace elements using by-products: sustainability and risks.

PubMed

Pérez-de-Mora, Alfredo; Madejón, Paula; Burgos, Pilar; Cabrera, Francisco; Lepp, Nicholas W; Madejón, Engracia

2011-10-01

We investigated the efficiency of various by-products (sugarbeet lime, biosolid compost and leonardite), based on single or repeated applications to field plots, on the establishment of a vegetation cover compatible with a stabilization strategy on a multi-element (As, Cd, Cu, Pb and Zn) contaminated soil 4-6 years after initial amendment applications. Results indicate that the need for re-treatment is amendment- and element-dependent; in some cases, a single application may reduce trace element concentrations in above-ground biomass and enhance the establishment of a healthy vegetation cover. Amendment performance as evaluated by % cover, biomass and number of colonizing taxa differs; however, changes in plant community composition are not necessarily amendment-specific. Although the translocation of trace elements to the plant biotic compartment is greater in re-vegetated areas, overall loss of trace elements due to soil erosion and plant uptake is usually smaller compared to that in bare soil. Copyright © 2011 Elsevier Ltd. All rights reserved.

Use of an ultra-clean sampling technique with inductively coupled plasma-mass spectrometry to determine trace-element concentrations in water from the Kirkwood-Cohansey Aquifer system, coastal plain, New Jersey

USGS Publications Warehouse

Ivahnenko, Tamara; Szabo, Zoltan; Hall, G.S.

1996-01-01

Water samples were collected during 1993 from 22 public supply wells screened in the Kirkwood-Cohansey aquifer system; concentrations of 18 trace elements were determined primarily by using inductively coupled plasma-mass spectrometry (ICP-MS) techniques, though graphite furnace atomic adsorption, hydride generation, and cold- vapor flameless atomic adsorption techniques were used for thallium, arsenic, and mercury, respectively, at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL). In addition, laboratory measurements of alkalinity and turbidity were made. The ground-water samples were collected by using ultra-clean sampling protocols developed by the USGS for collecting ground-water samples in areas with water containing low concentrations of trace elements. This technique is based on recently gained experience in sampling surface water for these elements. Field parameters (water temperature, specific conductance, pH, and dissolved-oxygen concentration) were monitored prior to sample collection. Three equipment blanks were collected to ensure that low-level trace-element contamination did not occur during sample collection. One split sample and a commercially- prepared reference standard were submitted to the NWQL o evaluate laboratory precision and accuracy, respectively. Trace-element concentrations in 10 sample splits and one equipment blank were also determined at the Rutgers University Chemistry Department laboratory. Results of the ICP-MS analyses and cold vapor flameless atomic absorption indicated that five trace elements-- cobalt, copper, lead, mercury, and nickel--were detectable in low concentrations (<0.1-29 mg/L) in most of the samples from the 22 wells, and four elements--aluminum, barium, manganese and zinc--were detected in higher concentrations than the other elements (30-710 mg/L for aluminum; 4-180 mg/L for barium, manganese, and zinc). The remaining nine trace elements were present in concentrations consistently lower than the minimum reporting limit. Turbidity was low (less than 1 nephelometric turbidity unit (NTU)), indicating that the trace-element concentrations were present in the dissolved phase and ideally would be reproducible in the absence of highly variable concentrations of particulates. The concentration of lead in one sample exceeded the U.S. Environmental Protection Agency (USEPA) action level of 15 mg/L; concentrations ranged from <1 to 16 mg/L. Mercury was frequently detected; concentrations ranged from <0.1 to 1.1 mg/L but did not exceed the USEPA maximum contaminant level. Results of analyses of the equipment blanks indicated that samples collected by using the new ultra-clean sampling protocols were free of low-level (< 1mg/L) trace-element contamination. The analysis of the split sample sent to the NWQL had a difference of 5 percent or less for all constituents except aluminum, for which the analysis had a difference of 10 percent. Results of ICP-MS analyses of split water samples sent to the Rutgers University Chemistry Department laboratory were, in general, in good agreement (within 10 percent) with those of the NWQL. Results of the analysis of the commercial standard agreed (within 5 percent) with the known concentrations of the trace elements. The quality-assurance data (three blanks, one split sample, and one standard), although not statistically evaluated because of the small data set, indicate that the measured trace-element concentrations are precise and accurate and that the samples were free of contamination at the microgram-per-liter level of contamination.

Response of cricket and spider motion-sensing hairs to airflow pulsations

PubMed Central

Kant, R.; Humphrey, J. A. C.

2009-01-01

Closed-form analytical solutions are presented for the angular displacement, velocity and acceleration of motion-sensing filiform hairs exposed to airflow pulsations of short time duration. The specific situations of interest correspond to a spider intentionally moving towards a cricket, or an insect unintentionally moving towards or flying past a spider. The trichobothria of the spider Cupiennius salei and the cercal hairs of the cricket Gryllus bimaculatus are explored. Guided by earlier work, the spatial characteristics of the velocity field due to a flow pulsation are approximated by the local incompressible flow field due to a moving sphere. This spatial field is everywhere modulated in time by a Gaussian function represented by the summation of an infinite Fourier series, thus allowing an exploration of the spectral dependence of hair motion. Owing to their smaller total inertia, torsional restoring constant and total damping constant, short hairs are found to be significantly more responsive than long hairs to a flow pulsation. It is also found that the spider trichobothria are underdamped, while the cercal hairs of the cricket are overdamped. As a consequence, the spider hairs are more responsive to sudden air motions. Analysis shows that while two spiders of different characteristic sizes and lunge velocities can generate pulsations with comparable energy content, the associated velocity fields display different patterns of spatial decay with distance from the pulsation source. As a consequence, a small spider lunging at a high velocity generates a smaller telltale far-field velocity signal than a larger spider lunging at a lower velocity. The results obtained are in broad agreement with several of the observations and conclusions derived from combined flow and behavioural experiments performed by Casas et al. for running spiders, and by Dangles et al. for spiders and a physical model of spiders lunging at crickets. PMID:19324674

Optical antenna gain. III - The effect of secondary element support struts on transmitter gain

NASA Technical Reports Server (NTRS)

Klein, B. J.; Degnan, J. J.

1976-01-01

The effect of a secondary-element spider support structure on optical antenna transmitter gain is analyzed. An expression describing the influence of the struts on the axial gain, in both the near and far fields, is derived as a function of the number of struts and their width. It is found that, for typical systems, the struts degrade the on-axis gain by less than 0.4 dB, and the first side-lobe level is not increased significantly. Contour plots have also been included to show the symmetry of the far-field distributions for three- and four-support members.

Unraveling the history of complex zoned garnets from the North Motagua Mélange (Guatemala)

NASA Astrophysics Data System (ADS)

Barickman, M. H.; Martin, C.; Flores, K. E.; Harlow, G. E.; Bonnet, G.

2016-12-01

The Guatemala Suture Zone (GSZ) is situated in central Guatemala, between the North American and Caribbean plates. Two serpentinite mélanges straddle the Motagua Fault system: the North Motagua Mélange (NMM) and the South Motagua Mélange (SMM). In this study, chemically zoned garnet grains from four eclogite blocks from the NMM were analyzed by EMPA for major elements and LA-ICP-MS for trace elements to unravel the geological history of the eclogites. These eclogites typically consist of euhedral to subhedral garnets, partly retrogressed omphacite grains, and accessory minerals such as phengite and epidote as inclusions in garnet. EBSD was employed to examine apparent garnet inclusions in garnet. The garnet grains in NMM eclogites display complex chemical zonations: all grains roughly show a spessartine-rich core, an almandine-rich core and/or intermediate zone, and a pyrope and grossular-rich rim. Additionally, crystal resorption can be observed between the different zones, and the pyrope-grossular rim can display oscillatory zoning. Finally, grossular-rich zones (crystallographically syntactic) within garnet are present in all studied samples. REE and spider diagrams do not show any significant difference in the patterns of the different zones within the garnet, or indicating that the chemical environment from which each garnet zone grew was broadly the same. The lack of significant variation in LILE content indicates that a fluid influx during garnet growth is unlikely. Consequently, we interpret that garnet grains grew in a largely closed system; however, the presence of the grossular-rich zones, argues for occasional excursions into conditions when either two garnets crystallized or Ca-rich overgrowths that were largely resorbed prior to subsequent continued garnet growth.

Determination of minor and trace elements in aromatic spices by micro-wave assisted digestion and inductively coupled plasma-mass spectrometry.

PubMed

Khan, Naeem; Choi, Ji Yeon; Nho, Eun Yeong; Jamila, Nargis; Habte, Girum; Hong, Joon Ho; Hwang, In Min; Kim, Kyong Su

2014-09-01

This study aimed at analyzing the concentrations of 23 minor and trace elements in aromatic spices by inductively coupled plasma-mass spectrometry (ICP-MS), after wet digestion by microwave system. The analytical method was validated by linearity, detection limits, precision, accuracy and recovery experiments, obtaining satisfactory values in all cases. Results indicated the presence of variable amounts of both minor and trace elements in the selected aromatic spices. Manganese was high in cinnamon (879.8 μg/g) followed by cardamom (758.1 μg/g) and clove (649.9 μg/g), strontium and zinc were high in ajwain (489.9 μg/g and 84.95 μg/g, respectively), while copper was high in mango powder (77.68 μg/g). On the whole some of the minor and essential trace elements were found to have good nutritional contribution in accordance to RDA. The levels of toxic trace elements, including As, Cd, and Pb were very low and did not found to pose any threat to consumers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Selenium deficiency risk predicted to increase under future climate change

PubMed Central

Jones, Gerrad D.; Droz, Boris; Greve, Peter; Gottschalk, Pia; Poffet, Deyan; McGrath, Steve P.; Seneviratne, Sonia I.; Smith, Pete; Winkel, Lenny H. E.

2017-01-01

Deficiencies of micronutrients, including essential trace elements, affect up to 3 billion people worldwide. The dietary availability of trace elements is determined largely by their soil concentrations. Until now, the mechanisms governing soil concentrations have been evaluated in small-scale studies, which identify soil physicochemical properties as governing variables. However, global concentrations of trace elements and the factors controlling their distributions are virtually unknown. We used 33,241 soil data points to model recent (1980–1999) global distributions of Selenium (Se), an essential trace element that is required for humans. Worldwide, up to one in seven people have been estimated to have low dietary Se intake. Contrary to small-scale studies, soil Se concentrations were dominated by climate–soil interactions. Using moderate climate-change scenarios for 2080–2099, we predicted that changes in climate and soil organic carbon content will lead to overall decreased soil Se concentrations, particularly in agricultural areas; these decreases could increase the prevalence of Se deficiency. The importance of climate–soil interactions to Se distributions suggests that other trace elements with similar retention mechanisms will be similarly affected by climate change. PMID:28223487

Selenium deficiency risk predicted to increase under future climate change.

PubMed

Jones, Gerrad D; Droz, Boris; Greve, Peter; Gottschalk, Pia; Poffet, Deyan; McGrath, Steve P; Seneviratne, Sonia I; Smith, Pete; Winkel, Lenny H E

2017-03-14

Deficiencies of micronutrients, including essential trace elements, affect up to 3 billion people worldwide. The dietary availability of trace elements is determined largely by their soil concentrations. Until now, the mechanisms governing soil concentrations have been evaluated in small-scale studies, which identify soil physicochemical properties as governing variables. However, global concentrations of trace elements and the factors controlling their distributions are virtually unknown. We used 33,241 soil data points to model recent (1980-1999) global distributions of Selenium (Se), an essential trace element that is required for humans. Worldwide, up to one in seven people have been estimated to have low dietary Se intake. Contrary to small-scale studies, soil Se concentrations were dominated by climate-soil interactions. Using moderate climate-change scenarios for 2080-2099, we predicted that changes in climate and soil organic carbon content will lead to overall decreased soil Se concentrations, particularly in agricultural areas; these decreases could increase the prevalence of Se deficiency. The importance of climate-soil interactions to Se distributions suggests that other trace elements with similar retention mechanisms will be similarly affected by climate change.

Trace elements and oxidative stress levels in the blood of painters in Lagos, Nigeria: occupational survey and health concern.

PubMed

Awodele, Olufunsho; Akinyede, Akin; Babawale, Omotola Opeyemi; Coker, Herbert A Babatunde; Akintonwa, Alade

2013-06-01

Adverse effects attributed to exposure to paints are currently a concern because of the continued widespread use of paint containing trace elements. Thus, occupational survey amongst painters in Lagos and determination of trace elements and oxidative stress parameters were carried out. Descriptive cross-sectional survey was done using a standardized questionnaire to obtain job safety-related information. Forty-eight percent of the painters were aware of hazards associated with painting and 52 % of these workers were aware of the necessary precautionary measures during painting. There were no significant differences (p ≥ 0.05) between the levels of trace elements in the blood of painters and the control subjects. However, there was a significance increase (p ≤ 0.0001) in the level of malondialdehyde and a decrease (p ≤ 0.001) in the levels of reduced glutathione, superoxide dismutase, and catalase of the painters compared to the control. An increase in oxidative stress parameters may not only be due to trace element concentrations, but also the painters' exposure to some petrochemical solvents during mixing of paints.

Infrared trace element detection system

DOEpatents

Bien, F.; Bernstein, L.S.; Matthew, M.W.

1988-11-15

An infrared trace element detection system includes an optical cell into which the sample fluid to be examined is introduced and removed. Also introduced into the optical cell is a sample beam of infrared radiation in a first wavelength band which is significantly absorbed by the trace element and a second wavelength band which is not significantly absorbed by the trace element for passage through the optical cell through the sample fluid. The output intensities of the sample beam of radiation are selectively detected in the first and second wavelength bands. The intensities of a reference beam of the radiation are similarly detected in the first and second wavelength bands. The sensed output intensity of the sample beam in one of the first and second wavelength bands is normalized with respect to the other and similarly, the intensity of the reference beam of radiation in one of the first and second wavelength bands is normalized with respect to the other. The normalized sample beam intensity and normalized reference beam intensity are then compared to provide a signal from which the amount of trace element in the sample fluid can be determined. 11 figs.

Age-related differences in hair trace elements: a cross-sectional study in Orenburg, Russia.

PubMed

Skalnaya, Margarita G; Tinkov, Alexey A; Demidov, Vasily A; Serebryansky, Eugeny P; Nikonorov, Alexandr A; Skalny, Anatoly V

2016-09-01

Age-related differences in the trace element content of hair have been reported. However, some discrepancies in the data exist. The primary objective of this study was to estimate the change in hair trace elements content in relation to age. Six hundred and eighteen women and 438 men aged from 10-59 years took part in the current cross-sectional study. Hair Cr, Mn, Ni, Si, Al, As, Be, Cd and Pb tended to decrease with age in the female sample, whereas hair Cu, Fe, I, Se, Li and Sn were characterised by an age-associated increase. Hair levels of Cr, Cu, I, Mn, Ni, Si and Al in men decreased with age, whereas hair Co, Fe, Se, Cd, Li and Pb content tended to increase. Hair mercury increased in association with age in men and in women, whereas hair vanadium was characterised by a significant decrease in both sexes. The difference in hair trace element content between men and women decreased with age. These data suggest that age-related differences in trace element status may have a direct implication in the ageing process.

Infrared trace element detection system

DOEpatents

Bien, Fritz; Bernstein, Lawrence S.; Matthew, Michael W.

1988-01-01

An infrared trace element detection system including an optical cell into which the sample fluid to be examined is introduced and removed. Also introduced into the optical cell is a sample beam of infrared radiation in a first wavelength band which is significantly absorbed by the trace element and a second wavelength band which is not significantly absorbed by the trace element for passage through the optical cell through the sample fluid. The output intensities of the sample beam of radiation are selectively detected in the first and second wavelength bands. The intensities of a reference beam of the radiation are similarly detected in the first and second wavelength bands. The sensed output intensity of the sample beam in one of the first and second wavelength bands is normalized with respect to the other and similarly, the intensity of the reference beam of radiation in one of the first and second wavelength bands is normalized with respect to the other. The normalized sample beam intensity and normalized reference beam intensity are then compared to provide a signal from which the amount of trace element in the sample fluid can be determined.

Influence of trace elements on dental enamel properties: A review.

PubMed

Qamar, Zeeshan; Haji Abdul Rahim, Zubaidah Binti; Chew, Hooi Pin; Fatima, Tayyaba

2017-01-01

Dental enamel, an avascular, irreparable, outermost and protective layer of the human clinical crown has a potential to withstand the physico-chemical effects and forces. These properties are being regulated by a unique association among elements occurring in the crystallites setup of human dental enamel. Calcium and phosphate are the major components (hydroxyapatite) in addition to some trace elements which have a profound effect on enamel. The current review was planned to determine the aptitude of various trace elements to substitute and their influence on human dental enamel in terms of physical and chemical properties.

What do the trace metal contents of urine and toenail samples from Qatar׳s farm workers bioindicate?

PubMed

Kuiper, Nora; Rowell, Candace; Nriagu, Jerome; Shomar, Basem

2014-05-01

Qatar׳s farm workers provide a unique population for exposure study: they are young, healthy males. This study combined trace element profiles in urine and toenail with survey information from 239 farm workers to assess the extent to which the biomarkers provide complementary exposure information. Urinary Mo levels (average=114 µg/L) were elevated; average urinary values (µg/L) for all other elements were: V (1.02), Cr (0.55), Mn (2.15), Fe (34.1), Co (0.47), Ni (2.95), Cu (15.0), As (47.8), Se (25.7), Cd (1.09), Ba (22.5), Pb (2.50) and U (0.15). Average toenail concentrations (mg/kg) were: Mn (2.48), Cu (4.43), As (0.26), Se (0.58), Mo (0.07), Cd (0.03), Ba (1.00), Pb (0.51) and U (0.02). No significant association was found between corresponding elements in urine and toenails. Elemental profiles suggest groundwater (with the exception of Mo) and soil-dust-crop exposure pathways cannot account for elemental variations. The main factors moderating trace element contents are related to depuration processes involving participants׳ trace element body burden prior to work in Qatar, and interactions of trace element metabolic cycles which over-ride the exposure footprint. Toenail and urine need to be carefully validated before reliable use as biomarkers of exposure in general populations for most elements in the study. Copyright © 2014 Elsevier Inc. All rights reserved.

Petroleum formation during serpentinization: the evidence of trace elements

NASA Astrophysics Data System (ADS)

Szatmari, P.; Fonseca, T. C.; Miekeley, N. F.

2002-05-01

An organic source of petroleum formation is well attested by many biomarkers. This need not, however, exclude contribution from inorganic sources. During serpentinization, in the absence of free oxygen, oxidation of bivalent Fe to magnetite breaks up the water molecule, generating hydrogen and creating one of the most reducing environments near the Earth's surface (Janecky & Seyfried, 1986). Szatmari (1989) proposed that some petroleum forms at plate boundaries by Fischer-Tropsch-type synthesis over serpentinizing peridotites and suggested that Ni, an element rare in the continental crust but important in both petroleum and the mantle, may be indicative of such a source. Recently, Holm and Charlou (2001) observed hydrocarbon formation by Fischer-Tropsch-type synthesis over serpentinizing peridotites of the Mid-Atlantic Ridge. To test whether the relative amounts of other trace elements in petroleum are in agreement with a serpentinizing source, we analyzed by internally coupled plasma-mass spectroscopy (ICP-MS) 22 trace elements in 68 oils sampled in seven sedimentary basins throughout Brazil. We found that trace elements in the oils correlate well with mantle peridotites and reflects the process of hydrothermal serpentinization during continental breakup. Four groups may be distinguished. In serpentinites, trace elements of the first group, Ti, Cr, Mn, and Fe, are largely retained in low-solubility magnetite and other spinels formed during serpentinization or inherited from the original peridotites. In the oils, when normalized to mantle peridotites, these elements are at relatively low levels, about 10,000 times less than their abundances in mantle peridotites, reflecting their low availability from stable minerals. In contrast, trace elements of the second group, which includes V, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Ba, La, Ce, and Nd, pass during serpentinization mostly into serpentine minerals or solution. In the oils, when normalized to mantle peridotites, these elements are at higher levels than those of the first group, about 300 times less than their abundances in mantle peridotites, reflecting their higher availability during serpentinization. Within both groups, trace metal ratios and A/(A+B) type proportionalities in the oils are close to mantle peridotites. V behaves somewhat differently: in lacustrine sequences V contents in the oils are low and the ratios of V to other elements of the second group are mantle-like, whereas in marine sequences V and its ratios to other trace elements rise by orders of magnitude. Trace elements commonly enriched in formation fluids and hydrothermal brines (Rb, Sr, Ba, Cu, Zn), when normalized to mantle peridotites, are enriched in the oils by about 0.5 order of magnitude relative to other elements of the second group. The third group of elements includes S, Mo, and As. These elements occur in the oils at abundances similar to sea water and are, when normalized to mantle peridotites and Ni, enriched in the oils by several orders of magnitude, indicating sea water reacting with peridotites during sepentinization as their possible source. Finally trace elements of the fourth group, such as Pb and Ag, are enriched in the oils by several orders of magnitude relative to both mantle peridotites and sea water and were presumably mobilized from shales by hydrothermal fluids. References:Holm, N.G. and Charlou, J.L., 2001, EPSL 191, 1-8. Janecky, D.R. and Seyfried, W.E., 1986, Geochim. Cosmochim. Acta 50, 1357-1378. Szatmari, P., 1989, AAPG Bull. 73, 989-998.

Filament condition-specific response elements control the expression of NRG1 and UME6, key transcriptional regulators of morphology and virulence in Candida albicans.

PubMed

Childers, Delma S; Kadosh, David

2015-01-01

Candida albicans is the most frequently isolated human fungal pathogen and can cause a range of mucosal and systemic infections in immunocompromised individuals. Morphogenesis, the ability to undergo a reversible transition from budding yeast to elongated filaments, is an essential virulence trait. The yeast-to-filament transition is associated with expression of genes specifically important for filamentation as well as other virulence-related processes, and is controlled, in part, by the key transcriptional regulators Nrg1 and Ume6. Both of these regulators are themselves controlled at the transcriptional level by filament-inducing environmental cues, although little is known about how this process occurs. In order to address this question and determine whether environmental signals regulate transcription of UME6 and NRG1 via distinct and/or common promoter elements, we performed promoter deletion analyses. Strains bearing promoter deletion constructs were induced to form filaments in YEPD plus 10% serum at 37°C, Spider medium (nitrogen and carbon starvation) and/or Lee's medium pH 6.8 (neutral pH) and reporter gene expression was measured. In the NRG1 promoter we identified several distinct condition-specific response elements for YEPD plus 10% serum at 37°C and Spider medium. In the UME6 promoter we also identified response elements for YEPD plus 10% serum at 37°C. While a few of these elements are distinct, others overlap with those which respond to Lee's pH 6.8 medium. Consistent with UME6 possessing a very long 5' UTR, many response elements in the UME6 promoter are located significantly upstream from the coding sequence. Our data indicate that certain distinct condition-specific elements can control expression of C. albicans UME6 and NRG1 in response to key filament-inducing environmental cues. Because C. albicans encounters a variety of host microenvironments during infection, our results suggest that UME6 and NRG1 expression can be differentially modulated by multiple signaling pathways to control filamentation and virulence in vivo.

Posterior Cord Syndrome and Trace Elements Deficiency as an Uncommon Presentation of Common Variable Immunodeficiency

PubMed Central

dos Santos Mota, Ananda; Morais Monteiro, Priscila; Carvalho, Angela Cristina Gouvêa; Fernandes Diniz, Barbara; Gemal Lanzieri, Pedro; Carneiro Ramos, Ricardo; Mocarzel, Luis Otavio

2017-01-01

Diarrhea is one of the most common symptoms in common variable immunodeficiency, but neurologic manifestations are rare. We presented a 50-year-old woman with recurrent diarrhea and severe weight loss that developed a posterior cord syndrome. Endoscopy found a duodenal villous blunting, intraepithelial lymphocytosis, and lack of plasma cells and magnetic resonance imaging of the spine was normal. Laboratory assays confirmed common variable immunodeficiency syndrome and showed low levels of trace elements (copper and zinc). Treatment was initiated with parenteral replacement of trace elements and intravenous human immunoglobulin and the patient improved clinically. In conclusion, physicians must be aware that gastrointestinal and neurologic disorders may be related to each other and remember to request trace elements laboratory assessment. PMID:28356913

In Situ Trace Element Analysis of an Allende Type B1 CAI: EK-459-5-1

NASA Technical Reports Server (NTRS)

Jeffcoat, C. R.; Kerekgyarto, A.; Lapen, T. J.; Andreasen, R.; Righter, M.; Ross, D. K.

2014-01-01

Variations in refractory major and trace element composition of calcium, aluminum-rich inclusions (CAIs) provide constraints on physical and chemical conditions and processes in the earliest stages of the Solar System. Previous work indicates that CAIs have experienced complex histories involving, in many cases, multiple episodes of condensation, evaporation, and partial melting. We have analyzed major and trace element abundances in two core to rim transects of the melilite mantle as well as interior major phases of a Type B1 CAI (EK-459-5-1) from Allende by electron probe micro-analyzer (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to investigate the behavior of key trace elements with a primary focus on the REEs Tm and Yb.

Application of multivariate analysis to investigate the trace element contamination in top soil of coal mining district in Jorong, South Kalimantan, Indonesia

NASA Astrophysics Data System (ADS)

Pujiwati, Arie; Nakamura, K.; Watanabe, N.; Komai, T.

2018-02-01

Multivariate analysis is applied to investigate geochemistry of several trace elements in top soils and their relation with the contamination source as the influence of coal mines in Jorong, South Kalimantan. Total concentration of Cd, V, Co, Ni, Cr, Zn, As, Pb, Sb, Cu and Ba was determined in 20 soil samples by the bulk analysis. Pearson correlation is applied to specify the linear correlation among the elements. Principal Component Analysis (PCA) and Cluster Analysis (CA) were applied to observe the classification of trace elements and contamination sources. The results suggest that contamination loading is contributed by Cr, Cu, Ni, Zn, As, and Pb. The elemental loading mostly affects the non-coal mining area, for instances the area near settlement and agricultural land use. Moreover, the contamination source is classified into the areas that are influenced by the coal mining activity, the agricultural types, and the river mixing zone. Multivariate analysis could elucidate the elemental loading and the contamination sources of trace elements in the vicinity of coal mine area.

Re-187-Os-187, Pt-190-Os-186 Isotopic and Highly Siderophile Element Systematics of Group IVA Irons

NASA Technical Reports Server (NTRS)

Walker, R. J.; McCoy, T. J.; Schulte, R. F.; McDonough, W. F.; Ash, R. D.

2005-01-01

We have recently completed Re-187-Os-187 and Pt-190-Os-186 isotopic and elemental studies of the two largest magmatic iron meteorite groups, IIAB and IIIAB [1]. These studies revealed closed-system behavior of both isotopic systems, but complex trace element behavior for Re, Pt and Os in group IIIAB. Here we examine isotopic and trace elemental systematics of group IVA irons. The IVA irons are not as extensively fractionated as IIAB and IIIAB and their apparently less complex crystallization history may make for more robust interpretation of the relative partitioning behavior of Re, Pt and Os, as well as the other highly siderophile elements (HSE) measured here; Pd, Ru and Ir [e.g. 2]. An additional goal of our continuing research plan for iron meteorites is to assess the possibility of relating certain ungrouped irons with major groups via trace element modeling. Here, the isotopic and trace element systematics of the ungrouped irons Nedagolla and EET 83230 are compared with the IVA irons.

Waveguide Calibrator for Multi-Element Probe Calibration

NASA Technical Reports Server (NTRS)

Sommerfeldt, Scott D.; Blotter, Jonathan D.

2007-01-01

A calibrator, referred to as the spider design, can be used to calibrate probes incorporating multiple acoustic sensing elements. The application is an acoustic energy density probe, although the calibrator can be used for other types of acoustic probes. The calibrator relies on the use of acoustic waveguide technology to produce the same acoustic field at each of the sensing elements. As a result, the sensing elements can be separated from each other, but still calibrated through use of the acoustic waveguides. Standard calibration techniques involve placement of an individual microphone into a small cavity with a known, uniform pressure to perform the calibration. If a cavity is manufactured with sufficient size to insert the energy density probe, it has been found that a uniform pressure field can only be created at very low frequencies, due to the size of the probe. The size of the energy density probe prevents one from having the same pressure at each microphone in a cavity, due to the wave effects. The "spider" design probe is effective in calibrating multiple microphones separated from each other. The spider design ensures that the same wave effects exist for each microphone, each with an indivdual sound path. The calibrator s speaker is mounted at one end of a 14-cm-long and 4.1-cm diameter small plane-wave tube. This length was chosen so that the first evanescent cross mode of the plane-wave tube would be attenuated by about 90 dB, thus leaving just the plane wave at the termination plane of the tube. The tube terminates with a small, acrylic plate with five holes placed symmetrically about the axis of the speaker. Four ports are included for the four microphones on the probe. The fifth port is included for the pre-calibrated reference microphone. The ports in the acrylic plate are in turn connected to the probe sensing elements via flexible PVC tubes. These five tubes are the same length, so the acoustic wave effects are the same in each tube. The flexible nature of the tubes allows them to be positioned so that each tube terminates at one of the microphones of the energy density probe, which is mounted in the acrylic structure, or the calibrated reference microphone. Tests performed verify that the pressure did not vary due to bends in the tubes. The results of these tests indicate that the average sound pressure level in the tubes varied by only 0.03 dB as the tubes were bent to various angles. The current calibrator design is effective up to a frequency of approximately 4.5 kHz. This upper design frequency is largely due to the diameter of the plane-wave tubes.

Mapping trace element distribution in fossil teeth and bone with LA-ICP-MS

NASA Astrophysics Data System (ADS)

Hinz, E. A.; Kohn, M. J.

2009-12-01

Trace element profiles were measured in fossil bones and teeth from the late Pleistocene (c. 25 ka) Merrell locality, Montana, USA, by using laser-ablation ICP-MS. Laser-ablation ICP-MS can collect element counts along predefined tracks on a sample’s surface using a constant ablation speed allowing for rapid spatial sampling of element distribution. Key elements analyzed included common divalent cations (e.g. Sr, Zn, Ba), a suite of REE (La, Ce, Nd, Sm, Eu, Yb), and U, in addition to Ca for composition normalization and standardization. In teeth, characteristic diffusion penetration distances for all trace elements are at least a factor of 4 greater in traverses parallel to the dentine-enamel interface (parallel to the growth axis of the tooth) than perpendicular to the interface. Multiple parallel traverses in sections parallel and perpendicular to the tooth growth axis were transformed into trace element maps, and illustrate greater uptake of all trace elements along the central axis of dentine compared to areas closer to enamel, or within the enamel itself. Traverses in bone extending from the external surface, through the thickness of cortical bone and several mm into trabecular bone show major differences in trace element uptake compared to teeth: U and Sr are homogeneous, whereas all REE show a kinked profile with high concentrations on outer surfaces that decrease by several orders of magnitude within a few mm inward. The Eu anomaly increases uniformly from the outer edge of bone inward, whereas the Ce anomaly decreases slightly. These observations point to major structural anisotropies in trace element transport and uptake during fossilization, yet transport and uptake of U and REE are not resolvably different. In contrast, transport and uptake of U in bone must proceed orders of magnitude faster than REE as U is homogeneous whereas REE exhibit strong gradients. The kinked REE profiles in bone unequivocally indicate differential transport rates, consistent with a double-medium diffusion model in which microdomains with slow diffusivities are bounded by fast-diffusing pathways.

Copper and Zinc Deficiency in a Patient Receiving Long-Term Parenteral Nutrition During a Shortage of Parenteral Trace Element Products.

PubMed

Palm, Eric; Dotson, Bryan

2015-11-01

Drug shortages in the United States, including parenteral nutrition (PN) components, have been common in recent years and can adversely affect patient care. Here we report a case of copper and zinc deficiency in a patient receiving PN during a shortage of parenteral trace element products. The management of the patient's deficiencies, including the use of an imported parenteral multi-trace element product, is described. © 2014 American Society for Parenteral and Enteral Nutrition.

An optimized chronology for a stalagmite using seasonal trace element cycles from Shihua Cave, Beijing, North China

NASA Astrophysics Data System (ADS)

Ban, F.; Baker, A.; Marjo, C.; Duan, W.; Li, X.; Coleborn, K.; Akter, R.; Nagra, G.

2017-12-01

Stalagmites play an increasingly important role in the paleoclimatic reconstruction from seasonal to orbital timescales. One of the important reasons is that 230Th-dating can provide an absolute age enabling more accurate knowledge of the stalagmite growth. Additionally, annual trace element and optical layers can provide complementary method for determining a precise age and seasonal resolution. The trace elements of a stalagmite (XMG) in Beijing Shihua Cave, which is located in the East Asian monsoon region, were analyzed by laser ablation ICP-MS and compared with stalagmite laminae. The results show that: (1) the polished section of the topmost 4 mm of stalagmite XMG has obvious bi-optical layers (fluorescence and visible light) under a conventional transmission microscope. In the rest of the sample laminae are not observed using this method. (2) The variations of P/Ca, Sr/Ca, Ba/Ca, U/Ca and Mg/Ca show seasonal cycles throughout the sample. Sr/Ca is inversely correlated to P/Ca, and its peaks correspond with the (non-fluorescing) white layers, which deposit in late winter and spring when the climate is dry. The peaks of P/Ca match closely with the (fluorescing) opaque layers, because P is a soil-derived element which increases in the high rainfall monsoon period. (3) The PCA of the five trace elements showed that the cycles of PC1 could represent the annual cycle. This stalagmite was deposited over 148 ± 4 years through peak counting and the cycles of PC1 correspond well with the annual layers. Trace element cyclicity as shown by PC1 can increase the accuracy of stalagmite dating, especially in the absence of obvious laminae. The trace elements can be used as the marker of seasonal changes in a strongly contrasting wet-dry monsoon climate regime. Keywords: high-precision dating; LA-ICP-MS; stalagmite; trace elements; seasonal cycles; Shihua Cave

Evaluation of frictional melting on the basis of trace element analyses of fault rocks

NASA Astrophysics Data System (ADS)

Ishikawa, T.; Ujiie, K.

2016-12-01

Pseudotachylytes (solidified frictional melts produced during seismic slip) found in exhumed accretionary complexes are considered to have formed originally at seismogenic depths, and help our understanding of the dynamics of earthquake faulting in subduction zones. The frictional melting should affect rock chemistry. Actually, major element compositions of unaltered pseudotachylyte matrix in the Shimanto accretionary complex are reported to be similar to that of illite, implying disequilibrium melting in the slip zone (Ujiie et al., 2007). Bulk-rock trace element analyses of the pseudotachylyte-bearing fault rocks also revealed their shift to the clay-mineral-like compositions (Honda et al., 2011). Toward better understanding of the frictional melting using chemical means, we carried out detailed major and trace element analyses for pseudotachylyte-bearing dark veins and surrounding host rocks from the Mugi area of the Shimanto accretionary complex (Ujiie et al., 2007). About one milligram each of samples was collected from a rock chip along the microstructure by using the PC-controlled micro-drilling apparatus, and then analyzed by ICP-MS. Host rocks showed a series of compositional trends controlled by mixing of detrital sedimentary components. Unaltered part of the pseudotachylyte vein, on the other hand, showed striking enrichment of fluid-immobile trace elements, consistent with selective melting of fine-grained, clay-rich matrix of the fault rock. Importantly, completely altered parts of the dark veins exhibit essentially the same characteristics as the unaltered part, indicating that the trace element composition of the pseudotachylyte is well preserved even after considerable alteration in the later stages. These results demonstrate that trace element and structural analyses are useful to detect preexistence of pseudotachylytes resulting from selective frictional melting of clay minerals. It has been controversial that pseudotachylytes are rarely formed or rarely preserved. Trace element analyses on clay-rich localized slipping zones shed light on this topic. References: Ujiie et al. (2007) J. Struct. Geol. 29, 599-613; Honda et al. (2011) GRL 38, L06310.

New insights into trace elements deposition in the snow packs at remote alpine glaciers in the northern Tibetan Plateau, China.

PubMed

Dong, Zhiwen; Kang, Shichang; Qin, Xiang; Li, Xiaofei; Qin, Dahe; Ren, Jiawen

2015-10-01

Trace element pollution resulting from anthropogenic emissions is evident throughout most of the atmosphere and has the potential to create environmental and health risks. In this study we investigated trace element deposition in the snowpacks at two different locations in the northern Tibetan Plateau, including the Laohugou (LHG) and the Tanggula (TGL) glacier basins, and its related atmospheric pollution information in these glacier areas, mainly focusing on 18 trace elements (Li, Be, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Nb, Mo, Cd, Sb, Cs, Ba, Tl, and Pb). The results clearly demonstrate that pronounced increases of both concentrations and crustal enrichment factors (EFs) are observed in the snowpack at the TGL glacier basin compared to that of the LHG glacier basin, with the highest EFs for Sb and Zn in the TGL basin, whereas with the highest EFs for Sb and Cd in the LHG basin. Compared with other studies in the Tibetan Plateau and surrounding regions, trace element concentration showed gradually decreasing trend from Himalayan regions (southern Tibetan Plateau) to the TGL basin (central Tibetan Plateau), and to the LHG basin (northern Tibetan Plateau), which probably implied the significant influence of atmospheric trace element transport from south Asia to the central Tibetan Plateau. Moreover, EF calculations at two sites showed that most of the heavy metals (e.g., Cu, Zn, Mo, Cd, Sb, and Pb) were from anthropogenic sources and some other elements (e.g., Li, Rb, and Ba) were mainly originated from crustal sources. MODIS atmospheric optical depth (AOD) fields derived using the Deep Blue algorithm and CALIOP/CALIPSO transect showed significant influence of atmospheric pollutant transport from south Asia to the Tibetan Plateau, which probably caused the increased concentrations and EFs of trace element deposition in the snowpack on the TGL glacier basin. Copyright © 2015 Elsevier B.V. All rights reserved.

[Distribution Characteristics and Source Analysis of Dustfall Trace Elements During Winter in Beijing].

PubMed

Xiong, Qiu-lin; Zhao, Wen-ji; Guo, Xiao-yu; Chen, Fan-tao; Shu, Tong-tong; Zheng, Xiao-xia; Zhao, Wen-hui

2015-08-01

The dustfall content is one of the evaluation indexes of atmospheric pollution. Trace elements especially heavy metals in dustfall can lead to risks to ecological environment and human health. In order to study the distribution characteristics of trace elements, heavy metals pollution and their sources in winter atmospheric dust, 49 dustfall samples were collected in Beijing City and nearby during November 2013 to March 2014. Then the contents (mass percentages) of 40 trace elements were measured by Elan DRC It type inductively coupled plasma mass (ICP-MS). Test results showed that more than half of the trace elements in the dust were less than 10 mg x kg(-1); about a quarter were between 10-100 mg x kg-1); while 7 elements (Pb, Zr, Cr, Cu, Zn, Sr and Ba) were more than 100 mg x kg(-1). The contents of Pb, Cu, Zn, Bi, Cd and Mo of winter dustfall in Beijing city.were respectively 4.18, 4.66, 5.35, 6.31, 6.62, and 8.62 times as high as those of corresponding elements in the surface soil in the same period, which went beyond the soil background values by more than 300% . The contribution of human activities to dustfall trace heavy metals content in Beijing city was larger than that in the surrounding region. Then sources analysis of dustfall and its 20 main trace elements (Cd, Mo, Nb, Ga, Co, Y, Nd, Li, La, Ni, Rb, V, Ce, Pb, Zr, Cr, Cu, Zn, Sr, Ba) was conducted through a multi-method analysis, including Pearson correlation analysis, Kendall correlation coefficient analysis and principal component analysis. Research results indicated that sources of winter dustfall in Beijing city were mainly composed of the earth's crust sources (including road dust, construction dust and remote transmission of dust) and the burning of fossil fuels (vehicle emissions, coal combustion, biomass combustion and industrial processes).

Distribution and solubility limits of trace elements in hydrothermal black smoker sulfides: An in-situ LA-ICP-MS study

NASA Astrophysics Data System (ADS)

Wohlgemuth-Ueberwasser, Cora C.; Viljoen, Fanus; Petersen, Sven; Vorster, Clarisa

2015-06-01

The key for understanding the trace metal inventory of currently explored VHMS deposits lies in the understanding of trace element distribution during the formation of these deposits on the seafloor. Recrystallization processes already occurring at the seafloor might liberate trace elements to later hydrothermal alteration and removement. To investigate the distribution and redistribution of trace elements we analyzed sulfide minerals from 27 black smoker samples derived from three different seafloor hydrothermal fields: the ultramafic-hosted Logatchev hydrothermal field on the Mid-Atlantic Ridge, the basaltic-hosted Turtle Pits field on the mid-atlantic ridge, and the felsic-hosted PACMANUS field in the Manus basin (Papua New Guinea). The sulfide samples were analyzed by mineral liberation analyser for the modal abundances of sulfide minerals, by electron microprobe for major elements and by laser ablation-inductively coupled plasma-mass spectrometry for As, Sb, Se, Te, and Au. The samples consist predominantly of chalcopyrite, sphalerite, pyrite, galena and minor isocubanite as well as inclusions of tetrahedrite-tennantite. Laser ablation spectra were used to evaluate the solubility limits of trace elements in different sulfide minerals at different textures. The solubility of As, Sb, and Au in pyrite decreases with increasing degree of recrystallization. When solubility limits are reached these elements occur as inclusions in the different sulfide phases or they are expelled from the mineral phase. Most ancient VHMS deposits represent felsic or bimodal felsic compositions. Samples from the felsic-hosted PACMANUS hydrothermal field at the Pual ridge (Papua New Guinea) show high concentrations of Pb, As, Sb, Bi, Hg, and Te, which is likely the result of an additional trace element contribution derived from magmatic volatiles. Co-precipitating pyrite and chalcopyrite are characterized by equal contents of Te, while chalcopyrite that replaced pyrite (presumably during black smoker growth) is enriched in Te relative to pyrite. These higher Te concentrations may be related to higher fluid temperature.

Bags with oven-dried moss for the active monitoring of airborne trace elements in urban areas.

PubMed

Giordano, S; Adamo, P; Monaci, F; Pittao, E; Tretiach, M; Bargagli, R

2009-10-01

To define a harmonized methodology for the use of moss and lichen bags as active monitoring devices of airborne trace elements in urban areas, we evaluated the element accumulation in bags exposed in Naples in different spring weather conditions for 6- and 12-weeks. Three different pre-exposure treatments were applied to moss and lichen materials: water-washing, acid-washing and oven-drying. During the different exposure periods in the Naples urban environment the moss accumulated always higher amounts of elements (except Hg) than lichens and the element accumulation increased during wetter weather and higher PM(10) conditions. The oven pre-treatment did not substantially modify the morphology and element composition of moss and the exposure in bags of this material for 6-weeks was sufficient to detect the pattern of airborne trace elements.

Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico and Texas; organic compounds and trace elements in bed sediment and fish tissue, 1992-93

USGS Publications Warehouse

Carter, L.F.; Anderholm, S.K.

1997-01-01

The occurrence and distribution of contaminants in aquatic systems are major components of the National Water-Quality Assessment (NAWQA) Program. Bed-sediment samples were collected at 18 sites in the Rio Grande Valley study unit between September 1992 and March 1993 to characterize the geographic distribution of organic compounds, including chlorinated insecticides, polychlorinated biphenyls (PCB's), and other chlorinated hydrocarbons, and also trace elements. Two-millimeter-size- fraction sediment was analyzed for organic compounds and less than 63-micron-size-fraction sediment was analyzed for trace elements. Concentrations of p,p'-DDE were detected in 33 percent of the bed-sediment samples. With the exception of DDT-related compounds, no other organochlorine insecticides or polychlorinated biphenyls were detected in samples of bed sediment. Whole-body fish samples were collected at 11 of the bed- sediment sites and analyzed for organic compounds. Organic compounds were reported more frequently in samples of fish, and more types of organic compounds were found in whole-body fish samples than in bed-sediment samples. Concentrations of p,p'-DDE were detected in 91 percent of whole-body fish samples. Polychlorinated biphenyls, cis-chlordane, trans-chlordane, trans- nonachlor, and hexachlorobenzene were other organic compounds detected in whole-body samples of fish from at least one site. Because of the extent of mineralized areas in the Rio Grande Basin arsenic, cadmium, copper, lead, mercury, selenium, and zinc concentrations in bed-sediment samples could represent natural conditions at most sites. However, a combination of natural conditions and human activities appears to be associated with elevated trace-element concentrations in the bed-sediment sample from the site Rio Grande near Creede, Colorado, because this sample exceeded the background trace-element concentrations calculated for this study. Fish-liver samples were collected at 12 of the bed-sediment sites and analyzed for trace elements. Certain trace elements were detected at higher concentrations in fish-liver samples than in bed-sediment samples from the same site. Both bed-sediment and fish-tissue samples are necessary for a complete environmental assessment of the occurrence and distribution of trace elements.

Reference Values of 14 Serum Trace Elements for Pregnant Chinese Women: A Cross-Sectional Study in the China Nutrition and Health Survey 2010-2012.

PubMed

Liu, Xiaobing; Zhang, Yu; Piao, Jianhua; Mao, Deqian; Li, Yajie; Li, Weidong; Yang, Lichen; Yang, Xiaoguang

2017-03-21

The development of reference values of trace elements is recognized as a fundamental prerequisite for the assessment of trace element nutritional status and health risks. In this study, a total of 1400 pregnant women aged 27.0 ± 4.5 years were randomly selected from the China Nutrition and Health Survey 2010-2012 (CNHS 2010-2012). The concentrations of 14 serum trace elements were determined by high-resolution inductively coupled plasma mass spectrometry. Reference values were calculated covering the central 95% reference intervals (P2.5-P97.5) after excluding outliers by Dixon's test. The overall reference values of serum trace elements were 131.5 (55.8-265.0 μg/dL for iron (Fe), 195.5 (107.0-362.4) μg/dL for copper (Cu), 74.0 (51.8-111.3) μg/dL for zinc (Zn), 22.3 (14.0-62.0) μg/dL for rubidium (Rb), 72.2 (39.9-111.6) μg/L for selenium (Se), 45.9 (23.8-104.3) μg/L for strontium (Sr), 1.8 (1.2-3.6) μg/L for molybdenum (Mo), 2.4 (1.2-8.4) μg/L for manganese (Mn), 1.9 (0.6-9.0) ng/L for lead (Pb), 1.1 (0.3-5.6) ng/L for arsenic (As), 835.6 (219.8-4287.7) ng/L for chromium (Cr), 337.9 (57.0-1130.0) ng/L for cobalt (Co), 193.2 (23.6-2323.1) ng/L for vanadium (V), and 133.7 (72.1-595.1) ng/L for cadmium (Cd). Furthermore, some significant differences in serum trace element reference values were observed between different groupings of age intervals, residences, anthropometric status, and duration of pregnancy. We found that serum Fe, Zn, and Se concentrations significantly decreased, whereas serum Cu, Sr, and Co concentrations elevated progressively compared with reference values of 14 serum trace elements in pregnant Chinese women. The reference values of serum trace elements established could play a key role in the following nutritional status and health risk assessment.

Trace Element Study of H Chondrites: Evidence for Meteoroid Streams.

NASA Astrophysics Data System (ADS)

Wolf, Stephen Frederic

1993-01-01

Multivariate statistical analyses, both linear discriminant analysis and logistic regression, of the volatile trace elemental concentrations in H4-6 chondrites reveal compositionally distinguishable subpopulations. Observed difference in volatile trace element composition between Antarctic and non-Antarctic H4-6 chondrites (Lipschutz and Samuels, 1991) can be explained by a compositionaily distinct subpopulation found in Victoria Land, Antarctica. This population of H4-6 chondrites is compositionally distinct from non-Antarctic H4-6 chondrites and from Antarctic H4 -6 chondrites from Queen Maud Land. Comparisons of Queen Maud Land H4-6 chondrites with non-Antarctic H4-6 chondrites do not give reason to believe that these two populations are distinguishable from each other on the basis of the ten volatile trace element concentrations measured. ANOVA indicates that these differences are not the result of trivial causes such as weathering and analytical bias. Thermoluminescence properties of these populations parallels the results of volatile trace element comparisons. Given the differences in terrestrial age between Victoria Land, Queen Maud Land, and modern H4-6 chondrite falls, these results are consistent with a variation in H4-6 chondrite flux on a 300 ky timescale. This conclusion requires the existence of co-orbital meteoroid streams. Statistical analyses of the volatile trace elemental concentrations in non-Antarctic modern falls of H4-6 chondrites also demonstrate that a group of 13 H4-6 chondrites, Cluster 1, selected exclusively for their distinct fall parameters (Dodd, 1992) is compositionally distinguishable from a control group of 45 non-Antarctic modern H4-6 chondrites on the basis of the ten volatile trace element concentrations measured. Model-independent randomization-simulations based on both linear discriminant analysis and logistic regression verify these results. While ANOVA identifies two possible causes for this difference, analytical bias and group classification, a test validation experiment verifies that group classification is the more significant cause of compositional difference between Cluster 1 and non-Cluster 1 modern H4-6 chondrite falls. Thermoluminescence properties of these populations parallels the results of volatile trace element comparisons. This suggests that these meteorites are fragments of a co-orbital meteorite stream derived from a single parent body.