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1.
The arthropod cuticle is a structurally diverse secretion that is largely composed of lipids, proteins, and α‐chitin that function together in protection, prey capture, and as a skeletal framework for efficient and diverse means of locomotion. Aquatic, aerial, and terrestrial arthropods are well known to enrich their cuticles with trace elements that are proposed to strengthen or otherwise enhance specific regions of the exoskeleton. In this study, we provide evidence that whipscorpions (vinegaroons) enrich their exoskeleton with up to 14 trace elements. We use energy‐dispersive x‐ray spectroscopy (EDS) to provide the first comparisons of trace element composition in two species of Thelyphonida: Mastigoproctus giganteus (female) and Typopeltis dalyi (female and male). We analyzed the chemical composition of eight regions that have sensory, locomotory, taxonomic, protective, and/or predatory significance: the flagellum, prosoma, tarsal claws of the walking legs, tarsi of the antenniform legs, chelicerae, and the terminal three segments of the pedipalps. Our results reveal the presence of 14 trace elements across both species (12 elements in T. dalyi, 10 elements in M. giganteus), and only four elements are present at significant levels (≥1% weight): Si, Cl, Ca, and Zn. The flagellum, antenniform leg tarsi, and prosoma keel lack these elements in both species, while the chelicerae of all species are enriched with Ca, Zn, and Cl, and the tarsal claws are enriched with Zn. Significantly, we note the presence of Si in the prosomal carapace (but not the keel) of males and females of Typopeltis only, which appears to be the first evidence of this transition metal in the arthropod exoskeleton. We discuss the significance of these chemical enrichments in whipscorpions and provide hypotheses about their functional significance.  相似文献   

2.
Electric discharge experiments have been performed in a plausible primitive earth atmosphere consisting of methane, nitrogen, and water over an aqueous phase of an ammonia-ammonium buffer solution. In some experiments, ions of metal elements, calcium, magnesium, zinc, iron and molybdenum were introduced. Gas phase products and amino acids in the liquid phase were analyzed by gas chromatography. With trace metal ions, less organic compounds in the gas phase and larger amounts of amino acids were obtained than without them. The results have shown the possible importance of trace elements in chemical evolution and the origin of life on the earth.  相似文献   

3.
Trace elements are used by all organisms and provide proteins with unique coordination and catalytic and electron transfer properties. Although many trace element-containing proteins are well characterized, little is known about the general trends in trace element utilization. We carried out comparative genomic analyses of copper, molybdenum, nickel, cobalt (in the form of vitamin B12), and selenium (in the form of selenocysteine) in 747 sequenced organisms at the following levels: (i) transporters and transport-related proteins, (ii) cofactor biosynthesis traits, and (iii) trace element-dependent proteins. Few organisms were found to utilize all five trace elements, whereas many symbionts, parasites, and yeasts used only one or none of these elements. Investigation of metalloproteomes and selenoproteomes revealed examples of increased utilization of proteins that use copper in land plants, cobalt in Dehalococcoides and Dictyostelium, and selenium in fish and algae, whereas nematodes were found to have great diversity of copper transporters. These analyses also characterized trace element metabolism in common model organisms and suggested new model organisms for experimental studies of individual trace elements. Mismatches in the occurrence of user proteins and corresponding transport systems revealed deficiencies in our understanding of trace element biology. Biological interactions among some trace elements were observed; however, such links were limited, and trace elements generally had unique utilization patterns. Finally, environmental factors, such as oxygen requirement and habitat, correlated with the utilization of certain trace elements. These data provide insights into the general features of utilization and evolution of trace elements in the three domains of life.  相似文献   

4.
Pistia stratiotes L. in a Nigerian lake receiving organic and laboratory chemical wastes, accumulated trace elements from the lake water. Its possible use in the treatment of specific industrial wastes or in selective enrichment of specific elements is discussed.  相似文献   

5.
A study of the leaf traces at the nodes in various species and varietal forms of Taxus, Torreya, Amentotaxus and Cephalotaxus reveals, only in Cephalotaxus, an unusual type of parenchymatous tissue associated with the xylem of the leaf trace. The cells of this tissue occur in one to three layers, have abundant cytoplasm and conspicuous nuclei. The thin walls of these cells are devoid of pits and show spiral or spiral-reticulate thickenings. These thickenings, although readily taking the counterstain, reveal the presence of lignin as determined by the phloroglucin test and by fluorescence microscopy. This tissue is always internal—that is, adaxial—to the protoxylem of the trace. From the node it accompanies the trace for a short distance into the leaf base, where it gives way centrally to the typical leaf parenchyma and laterally to the transfusion tissue on the flanks of the bundle. In the basipetal direction it is in contact with the inner face of the annular protoxylem of the stele, eventually disappearing in the typical pith parenchyma. This tissue occasionally reveals instances of well-lignified tracheid-like centripetal elements. On the basis of the characteristics of this tissue, it is suggested that its origin lies in former centripetal xylem. The significance of this tissue to the evolution of the stele and the systematic position of Cephalotaxus is discussed.  相似文献   

6.
BackgroundMetals are a minor constituent in honey, but they have been suggested to be a potential tool to characterize honeys according to their botanical or geographical origin.MethodsA total of 40 metals were analyzed by Inductively Coupled Plasma-Mass Spectrometry in monofloral and multifloral honeys from Northwestern Italy. PCA and ANOVA were used to discriminate honeys according to the various floral types.ResultsThe highest levels of trace elements and rare earth elements (REEs) were found in chestnut honey, while the lowest concentrations were recorded in acacia and rhododendron honeys. Rubidium and aluminum were the most represented nonessential elements, while manganese, iron, zinc and copper had the highest values of the essential elements. Potentially toxic elements arsenic, cadmium and lead were close to or below the limit of quantification.ConclusionsThe present study showed significant differences in metal concentrations according to honey floral type, reflecting the strong influence of botanical origin on the chemical composition of this particular food.  相似文献   

7.
Abstract

The lichen Pseudevernia furfuracea was exposed to environmental trace elements in the district of Acerra (province of Naples, southern Italy), one of the points forming Italy's “Triangle of Death”. P. furfuracea thalli were exposed in bags at different sites for 6 months, periodically collected and examined by transmission electron microscopy (TEM) to assess ultrastructural changes. An our earlier study demonstrated that these exposed lichens were strongly contaminated by trace elements (Sorbo S, Aprile G, Strumia S, Castaldo Cobianchi R, Leone A, et al. 2008. Trace element accumulation in P. furfuracea (L.) Zopf exposed in Italy's so-called Triangle of Death. Sci Total Environ 407: 647–654.). The algal cells were more affected than the fungal symbiont. Exposition at urban sites gave the most frequent changes. Four trace elements (Cd, Pb, Cu and Zn) were used to study the effects of ultrastructural trace element both in field and in vitro treatments. The lichen developed comparable ultrastructural changes when exposed to different trace elements and the changes were not specific to the treatment used (lichen bag exposition, in field and in vitro treatments). The in vitro treatment gave the highest frequency of damage at all time points. X-ray TEM microanalysis revealed trace elements inside the cell walls and the cytoplasmic vesicles of the lichens cultured with the trace elements; this localization is probably related to tolerance mechanisms.  相似文献   

8.
Abstract

Browse tree leaves of six species of Acacia (A. angustissima L., A. drepanolobium L., A. nilotica L., A. polyacantha L., A. senegal L., A. tortilis L.) were screened for chemical composition, including minerals and trace elements. Crude protein (CP) varied among the species from 145 (A. senegal) to 229 g/kg DM (A. angustissima). The species had moderate to high levels of minerals. The concentrations of Ca, P, Mg and S varied among the species from 14.6 – 31.5, 3.5 – 4.9, 1.4 – 3.0 and 1.7 – 2.8 g/kg DM, respectively. The forages showed relatively low concentrations of trace elements. Content of trace elements varied among the species from 4.5 – 23.8, 99.4 – 173.6, 146.2 – 432, 41.0 – 90.1, 10.9 – 22.2 and 0.05 – 0.65 mg/kg DM for Cu, Mo, Fe, Mn, Zn and Co, respectively. All leaves of browse species would meet the normal requirements for Ca, P, Mg and S in ruminants, although some species had higher levels of Ca than tabulated mineral requirements in livestock. Assayed Cu, Mn, Zn and Co would satisfy the lower range of recommended requirements of trace elements depending on their bioavailability. Therefore, browse leaves from Acacias could form good sources of CP and mineral supplements to ruminants.  相似文献   

9.
A number of essential trace elements play a major role in various metabolic pathways. Selenium (Se), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) are essential trace elements that have been studied in many diseases, including autoimmune, neurological, and psychiatric disorders. However, the findings of previous research on the status of trace elements in patients with schizophrenia have been controversial. We studied these elements in patients with a DSM-IV diagnosis of schizophrenia and compared them with sex- and age-matched healthy controls. Plasma Cu concentrations were significantly higher (p<0.01) and Mn and Fe concentrations were lower (p<0.05 and p<0.05, respectively) in schizophrenic patients than in controls. Se and Zn concentrations and protein levels did not differ between patients and healthy controls. These observations suggest that alterations in essential trace elements Mn, Cu, and Fe may play a role in the pathogenesis of schizophrenia. However, findings from trace element levels in schizophrenia show a variety of results that are difficult to interpret.  相似文献   

10.
We examined leaf and pollen histochemical properties in Parietaria L. and measured trace element concentrations in urban sites in Palermo, Sicily, affected by different stress valence levels. Urban pollution affects histochemistry macro-, micro-, and toxic element concentrations in Parietaria. We therefore decided to determine whether this plant can be used as a simple biomonitor or bioaccumulator of pollution contaminants. Samples were collected at various sites in different periods. An increase in phenolic compound levels was a result of the impact of pollution. Histochemical characteristics and trace element concentrations varied according to the period, but not to the place, of sampling. Pollutant concentrations were the highest in the month of February 2002. Trace metal concentrations were the lowest in July. Our investigations have confirmed that Parietaria L. can be used to study the effects of trace elements in the atmosphere in urban sites; in fact, they are veritable accumulators, given that elevated levels of pollutants can be found on their structures with no visible morphological effects. There are differences in accumulation capacity according to the trace elements studied. Pollution alters the content of phenolic compounds and chemical elements in Parietaria L.  相似文献   

11.
Attempts were made to extend the storage life of seed potatoes by treating them with trace elements as antimicrobial and antisprouting agents. In tests to measure the growth of Fusarium oxysporum, and Erwinia carotovora pv. carotovora it was found to be decreased more by iron, copper and zinc than by boron, manganese and molybdenum. Dipping seed tubers in aqueous solutions of trace element salts decreased both sprouting and microbial spoilage during storage at ambient conditions. Field testing at the end of storage proved that treating seed potatoes with ferrous sulphate did not decrease the yield of tubers or increase their iron content. It is suggested that trace elements may be used to extend the storage life of seed potato tubers, in tropical conditions.  相似文献   

12.
Body‐element content was measured for three life stages of wild Atlantic salmon Salmo salar from three distinct Newfoundland populations as individuals crossed between freshwater and marine ecosystems. Life stage explained most of the variation in observed body‐element concentration whereas river of capture explained very little variation. Element composition of downstream migrating post‐spawn adults (i.e. kelts) and juvenile smolts were similar and the composition of these two life stages strongly differed from adults migrating upstream to spawn. Low variation within life stages and across populations suggests that S. salar may exert rheostatic control of their body‐element composition. Additionally, observed differences in trace element concentration between adults and other life stages were probably driven by the high carbon concentration in adults because abundant elements, such as carbon, can strongly influence the observed concentrations of less abundant elements. Thus, understanding variation among individuals in trace elements composition requires the measurement of more abundant elements. Changes in element concentration with ontogeny have important consequences the role of fishes in ecosystem nutrient cycling and should receive further attention.  相似文献   

13.
Present study investigates relationships between total and bioaccessibility of trace elements (Cd, Co, Cr, Cu, Mn, NI, Pb, V, and Zn) concentrations in sediment and their bioaccumulation in species in Shadegan wetland in southwest of Iran. Bioavailability factor (BAF) and translocation factor (TF) were calculated in plants and trophic transfer factor (TTF) was determined in bird species. For this purpose, sampling of sediments, aquatic plants including Phragmites australis, Typha australis, Scripus maritimus and two bird species encircling Porphyrio porphyrio and globally threatened Marmaronetta angustirostris were carried out during winter 2009. Result of chemical analysis show that bioaccessibility concentrations of Mn (8.31 mg/kg), V (1.33 mg/kg), and Pb (1.03 mg/kg) are higher than other metals. The uptake trend of trace elements in plant decreases as root > stem > leaf. Accumulation levels of trace elements in different tissues of P. porphyrio and M. angustirostris are almost identical and considerable. Accumulation and toxicity of Cd in birds is more than plants. In addition, BAF of V, Pb, and Cr indicates high accumulation by plants and great pollution rate in the area of study. In S. maritimus TF for Mn, Cu, Pb, and V are high whereas in T. australis, Cu and Pb posses the highest TF. Also Cr, Co, Mn, Ni, and Zn have higher TF from stem to leaf than root to stem in P. australis. Finally, TTFs were compared in various bird species.  相似文献   

14.
Several trace elements are essential nutrients for an optimal functioning of organs and tissues, including the immune system and the heart. The pathogenesis of some heart diseases has been associated with changes in the balance of certain trace elements. The etiology of nonrheumatic aortic valve sclerosis is unknown, however. A prospective study was performed on trace element changes in the sclerotic valves of 46 patients undergoing surgical aortic valve replacement because of aortic stenosis. Valves from 15 individual forensic cases without known cardiac disease served as controls. The contents of 15 trace elements (Al, As, Cd, Ca, Co, Cu, Fe, Pb, Mg, Mn, Hg, Se, Ag, V, and Zn) were measured by inductively coupled plasma — mass spectrometry (ICP-MS) of aortic valve tissue from both patients and forensic autopsy controls. Some trace elements showed similar concentrations in sclerotic and control valves (Al, Ag, Hg, Mn), whereas a few were moderately changed in the sclerotic as compared with the control valves, including an increase in Cd by 52% (p<0.05) and decreases in Se by 14% (p<0.05), in V by 42% (p<0,001), and in Cu by 45% (p<0.001). However, there were pronounced increases (p<0.001) in the concentrations of As (5-fold), Ca (70-fold), Co(10-fold), Fe (20-fold), Pb (8-fold), Mg (20-fold), and Zn (10-fold) in the sclerotic valves. Thus, sclerotic aortic valve disease is associated with a pronounced imbalance in several trace elements of well-known importance for cardiovascular and immune function as well as in trace elements with hitherto unknown significance.  相似文献   

15.

Background  

Pachycladon (Brassicaceae, tribe Camelineae) is a monophyletic genus of ten morphologically and ecogeographically differentiated, and presumably allopolyploid species occurring in the South Island of New Zealand and in Tasmania. All Pachycladon species possess ten chromosome pairs (2n = 20). The feasibility of comparative chromosome painting (CCP) in crucifer species allows the origin and genome evolution in this genus to be elucidated. We focus on the origin and genome evolution of Pachycladon as well as on its genomic relationship to other crucifer species, particularly to the allopolyploid Australian Camelineae taxa. As species radiation on islands is usually characterized by chromosomal stasis, i.e. uniformity of chromosome numbers/ploidy levels, the role of major karyotypic reshuffling during the island adaptive and species radiation in Pachycladon is investigated through whole-genome CCP analysis.  相似文献   

16.
17.
Despite the nutritional value of Colophospermum mopane to browser's diets, there is still insufficient knowledge on the effect of browsers on concentrations of these trace elements. A field experiment was conducted in Musina Nature Reserve, Limpopo Province, South Africa, to determine the effect of pruning on the concentration of trace elements in mopane leaves. Samples were analysed for iron (Fe), manganese (Mn), boron (B), molybdenum (Mo), copper (Cu), zinc (Zn), cobalt (Co), fluoride (F) and selenium (Se) using the inductively coupled plasma atomic emission spectrometry technique. The effect of pruning was tested using the two‐tailed t‐test: two‐sample assuming equal variance and two‐tailed Mann–Whitney U‐test. Results showed that the concentration of trace elements in the control and pruned trees varies slightly through the year. Fe, Mn, Mo, Cu, Zn and Se are higher during leaf flush, but declined as the leaves matured and aged. This study concluded that simulated browsing had no significant effect on the concentration of trace elements in the mopane leaves. Seasonal variation in the amount of trace elements has implications on the distribution of browsers in the mopane woodland.  相似文献   

18.

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.

  相似文献   

19.

Enigmatic rod-like skeletal structures that support compliant membranes (patagia) in aerial mammals have been often considered as neomorphic elements or as evolutionary novelties, and their origin has remained poorly understood. A potential source of skeletal plasticity and, probably, of morphofunctional innovations are sesamoids, which were recently demonstrated to have a common cellular origin with bone eminences. In this review, I compile information regarding anatomy, evolution, and development of rod-like skeletal elements in extant gliding and flying mammals and propose a working hypothesis on the origin of these structures. Rod-like skeletal elements, namely, the calcar in bats (Chiroptera), the unciform element in Anomaluridae (Rodentia), and the styliform cartilage in Pteromyini (Rodentia: Sciuridae), would derive from sesamoids, which, in turn, would have the same origin as eminences of long bones (or bones with a long-bone-like growth), i.e., calcaneus, ulna, and pisiform, respectively. Rod-like skeletal elements exhibit several features of sesamoids. However, further developmental data are needed to confirm this hypothesis, particularly whether these structures share a cellular origin and molecular developmental pathways with sesamoids and bone eminences. If this hypothesis were supported, a new role for sesamoids in generating morphofunctional innovations in mammals and, potentially, in other aerial amniotes, would be recognized. Rod-like skeletal elements, which are key in the evolution of aerial locomotion, might constitute an example of pre-existing traits that acquire novel functions through relatively little developmental plasticity.

  相似文献   

20.
The ability to recognize the former existence of microbes as well as the biological origin of marine precipitates, such as putative microbialites, is crucial for understanding the development and history of early life on Earth. Increasingly, such rocks hold keys to understanding the geochemical evolution of the oceans and linked Earth systems. Vital trace elements previously have received relatively little attention as clues to the origin of carbonate rocks, and low abundance transition elements in particular, have been difficult to analyse in carbonate matrices for technical reasons. We have used laser ablation–inductively coupled plasma–mass spectroscopy for the in situ measurement of a broad suite of vital transition metals in Late Devonian reefal limestones that contain coeval microbialite (the calcimicrobe Renalcis), stromatoporoid sponge skeleton, early marine cement, and later diagenetic cement. Comparative experiments conducted in two different ion extraction modes determined theoretical detection limits for transition elements on NIST reference material SRM 612. Analyses of NIST glasses SRM 614 and 616 demonstrate accuracy relative to previously published data. On that basis we have identified significant enrichment of the vital elements V, Sn, Cu and Zn within the Renalcis. The stromatoporoid skeleton by contrast is enriched only in V. Earliest cements, which also may have been mediated to some degree by microbial biofilms on the basis of their morphology, show a much smaller degree of enrichment, and later cements show no enrichment, with the exception of Zn, which is concentrated in the latest cement. Fine particulate carbonate sediments (micrite) show variable metal enrichments that are attributable to varying contributions from detrital siliciclastic contamination. Renalcis was also enriched above the sponge and cements in regards to Mn, Cd, Co, and possibly Cr, but at less robust levels. Molybdenum and Sb were found not to be enriched in the Renalcis, and Ni, although clearly very low in concentration, could not be evaluated owing to its high detection limit. We additionally were able to identify specific zones of contamination in Renalcis encountered as the laser drilled deeper into the carbonate. Time resolved analysis allows exclusion of such contaminants from integration into the results. Successful application of the new technique will now allow us to assess metal uptake in ancient carbonates with implications for interpreting the biogenicity of putative microbialites.  相似文献   

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