Lycopodium Spores Research Articles

A trainable object finder, selector and identifier for pollen, spores and other things: A step towards automated pollen recognition in lake sediments

Pollen records are the most important proxy for reconstructing past terrestrial vegetation. While new approaches for improved quantitative interpretation of pollen data have been developed over the last decades, the availability of pollen records remains mostly limited because pollen samples are still analysed manually, which is a time-consuming task and requires extensive training. Here, we present an approach for automated recognition of pollen and spores from lake sediments using deep convolutional neural networks and machine learning. The approach includes two stages. The detector first locates pollen and spores in the sample matrix, and the classifier then classifies these objects. We have trained the approach on two pollen datasets from two lakes in north-eastern Germany. So far, our approach is able to automatically recognise 10 pollen types and Lycopodium spores with high accuracy. As soon as more training data are available, more pollen and spore types can be added. The preparation of training data, the training of the neural networks and their application are accessible via a freely available, browser-based user interface called TOFSI.

Induction of Conjugation and Zygospore Cell Wall Characteristics in the Alpine Spirogyra mirabilis (Zygnematophyceae, Charophyta): Advantage under Climate Change Scenarios?

Extreme environments, such as alpine habitats at high elevation, are increasingly exposed to man-made climate change. Zygnematophyceae thriving in these regions possess a special means of sexual reproduction, termed conjugation, leading to the formation of resistant zygospores. A field sample of Spirogyra with numerous conjugating stages was isolated and characterized by molecular phylogeny. We successfully induced sexual reproduction under laboratory conditions by a transfer to artificial pond water and increasing the light intensity to 184 µmol photons m−2 s−1. This, however was only possible in early spring, suggesting that the isolated cultures had an internal rhythm. The reproductive morphology was characterized by light- and transmission electron microscopy, and the latter allowed the detection of distinctly oriented microfibrils in the exo- and endospore, and an electron-dense mesospore. Glycan microarray profiling showed that Spirogyra cell walls are rich in major pectic and hemicellulosic polysaccharides, and immuno-fluorescence allowed the detection of arabinogalactan proteins (AGPs) and xyloglucan in the zygospore cell walls. Confocal RAMAN spectroscopy detected complex aromatic compounds, similar in their spectral signature to that of Lycopodium spores. These data support the idea that sexual reproduction in Zygnematophyceae, the sister lineage to land plants, might have played an important role in the process of terrestrialization.

Трассирование в гидрогеологии подземных водотоков с помощью ДНК-метчиков

Underground water sources and their movement in various rocks, including karsts, are of considerable interest for many reasons, among which human economic activity plays a significant role. Various compounds are used to trace underground waters – stable and radioactive isotopes, microorganisms and bacteriophages, solid particles as lycopodium spores, chlorides and bromides, other ions, as well as fluorescent dyes. Relatively recently, DNA molecules have been used for this purpose, which can be detected with high sensitivity using a polymerase chain reaction. The commonly used number of DNA tracers is 1015 - 1016 molecules, which, despite significant dilution by water flows, ensures their subsequent detection. In addition to the high sensitivity of such analyses, other advantages of DNA molecules for tracing watercourses are their harmlessness for ecology, relative cheapness. In view of the possible destruction of DNA molecules in an aqueous medium and their sorption on various rocks, it is proposed to use encapsulated molecules, the shells of which are polylactic acid, silica, alginate and other compounds. An experiment on tracing the watercourse of the Tyutyulena stream from the ponor at the Kosh cave to the Traval griffin is predicted, indicating that in this case, taking into account the water flow, only about 1012 DNA molecules will be enough.

Pinworm research in the Southwest USA: five decades of methodological and theoretical development and the epidemiological approach

Pinworms infected Ancestral Pueblo populations since early periods of occupation on the Colorado Plateau. The high prevalence of pinworm found in these populations was correlated with the habitation style developments through time. However, in previous studies, Turkey Pen Cave, an early occupation site, and Salmon Ruins, a late occupation site, exhibited prevalences that were anomalously low, suggesting that these sites were outliers. Alternatively, it is possible that the previous quantification method was not successful in detecting the real prevalence and eggs per gram, which led to inexact interpretations. The aims of this study were to verify if previous pinworm prevalences for Turkey Pen Cave and Salmon Ruins were underestimated. In addition, new analyses were added to the data set. Two latrines from Aztec Ruins, a Pueblo III occupation never studied before, were sampled and studied. We applied the pathoecology concept and descriptive/comparative parasitological statistical parameters. Human coprolites were weighed and rehydrated along with introduced exotic Lycopodium tablets and screened through 250-μm mesh. Parasite eggs and Lycopodium spores were quantified and eggs per gram were estimated for each sample. Parasitological statistical parameters were calculated at Quantitative Parasitology 3.0 software. Pinworm was the only parasite recovered in all sites. The prevalences observed in early and late occupation sites refute previous correlation with habitation style. This study indicates that the previously estimated prevalences were underestimated, which interfered in the accurate interpretation on Ancestral Pueblo pinworm infection. This study reveals a new paleoparasitological panorama of pinworm infection in Ancestral Pueblo populations.

Contribution to the Eco-Palynological Studies of Wadi El Natron, Egypt

Palynological study of three soil profiles has been carried out from the Wadi El-Natrun area, Western Desert of Egypt for their pollen content dating Late Pliocene to present. Results revealed predominance of Mangroves vegetation Avicennia marina during Late Pliocene, and, Early Pleistocene. A warm humid climate with intermittent dry periods is indicated from the Late Pliocene recorded fossils. Fossil remains of Juncus and Salsola pollen types. Lycopodium spores, Pinus and Concentricystes spores were recorded during Late Pliocene and Holocene, Early Pleistocene which suggest a humid and warm climate at this period. The climate was warm arid alternating with warm humid and sometimes cool-temperate rainy periods as indicated by the presence of grasess (Poaceae) and (conifer, Pinus). Swamp elements, Typha and phragmites pollen types were recorded with high percentage indicating a swampy habitat during Holocene period. The present vegetation cover of the studied area represented by 27 species belonging to 12 families, 4 annuals and 23 perennial plants and a few individuals of Acacia, Tamarix type the most dominant shrubs, followed by associate types e.g halophytes Salsola, Zygophyllum, Cornulaca and few of annuals Senecio and Sonchus which represent mesophytic species, while the differences in vegetation of present and old may due to the environmental and climatic changes. In the present, the rising salinity and high nutrient loading due to human activities has allowed for the growth of the halophytic community. So, Palynological investigations may be used to detect the effects of climatic changes on terrestrial plant vegetation and as additional tool to predict the past climatic changes.

Investigation of the Fate of Proteins and Hydrophilicity/Hydrophobicity of Lycopodium clavatum Spores after Organic Solvent-Base-Acid Treatment.

Microcapsules extracted from lycopodium ( Lycopodium clavatum) spores have been increasingly used as an oral therapeutic carrier. A series of sequential treatments involving acetone, KOH, and H3PO4 are used to extract a protein-free hollow microcapsule. This study focuses on two critical aspects of lycopodium spores: the fate of native proteins and the wettability of the spores after a chemical treatment. Protein-free spores are desired to prevent an allergic reaction, whereas the wettability is critical for the formulation development. Although the chemically treated lycopodium spores are generally regarded as protein free, the studies that have reported this have not gone into significant depths to understand the nature of residual nitrogen observed even in spores thought to be protein free. Wettability of spores has not received any significant attention. Accordingly, in this study, we performed a comprehensive analysis of natural spores and spores after each chemical treatment step. We show that natural lycopodium spores are hydrophobic and contain low-molecular-weight proteins (∼10 kD). Acetone treatment partially solubilizes unsaturated phospholipids from the spores. Nevertheless, the acetone-treated spores retain native proteins and are still hydrophobic. KOH treatment, however, removes a significant amount of proteins and partially hydrolyzes esters to carboxylic acid salts and results in a hydrophilic spore with a good wettability. Finally, we show that the H3PO4 treatment removes residual proteins, hydrolyzes remaining esters to carboxylic acids, and dissolves carbohydrates. H3PO4 treatment temperature controls carbohydrate dissolution, which in turn affects the hydroxyl functional groups and hydrophilicity (wettability) of the treated spores. Spores treated at 60 °C as opposed to 160 °C are amphiphilic in nature due to the abundance of hydroxyl functional groups on the surface. In conclusion, this study confirms the removal of native proteins from treated spores and sheds light on the chemical changes that the spores undergo after chemical treatment and correlates these changes to their wettability.

3D-Printable Model of a Particle Trap: Development and Use in the Physics Classroom

Quadrupole ion traps are modern and versatile research tools used in mass spectrometers, in atomic frequency and time standards, in trapped ion quantum computing research, and for trapping anti-hydrogen ions at CERN. Despite their educational potential, quadrupole ion traps are seldom introduced into the physics classroom not least because commercial quadrupole ion traps appropriate for classroom use are expensive and difficult to set up. We present an open hardware 3D-printable quadrupole ion trap suitable for the classroom, which is capable of trapping lycopodium spores. We also provide student worksheets developed in an iterative design process, which can guide students while discovering particle traps. The quadrupole ion trap operates using a 3 kV 50 Hz alternating current power supply and uses an astable multivibrator circuit including high luminosity LEDs to illuminate the spores, using the stroboscopic effect to exhibit their movement. The trap can be used in teaching laboratories to enhance high school and university students’ understanding of electric fields and their applications.

A methodology to produce eco-friendly superhydrophobic coatings produced from all-water-processed plant-based filler materials

Eco-friendly, water-repellent coatings made by combining lycopodium spores and a natural wax.

Memory effect and anisotropy of particle arrangements in granular paste.

It is known that pastes of fine powder, for example those of clay, retain memory of shaking applied early in a drying process. This memory results in the appearance of anisotropic patterns of desiccation cracks after drying. In this work, we find a similar behavior in pastes consisting of large granular particles, specifically cornstarch and Lycopodium spores. Because of the large particle size, we were able to observe particle arrangements in Lycopodium paste with micro-focus X-ray computerized tomography ( μ CT). We prepared pastes consisting of Lycopodium particles and water. Agar was added to the paste in order to allow for solidification during a drying process. In these samples, we found statistical anisotropy induced by shaking applied early in the drying process. This anisotropy possesses a feature that was predicted on the basis of results obtained in previous experimental and theoretical studies.

Black ceramic spheres as marker grains for microfossil analyses, with improved chemical, physical, and optical properties

Marker grain method is commonly used by palynologists to quantify absolute pollen concentration in sediments. DuPont NEM plastic microbeads and Lycopodium spore tablets are two of the most commonly used marker grains. The DuPont NEM series has an obvious advantage over Lycopodium tablets because Lycopodium is not guaranteed ‘exotic’ in many ecosystems (especially in the past). Moreover, NEM also has high visibility, easily identifiable spherical shape, and availability in different size ranges. However, the production of NEM has been discontinuous since more than a decade, and palynologists of the world are using the precious remainders of their own stock in very small (=suboptimal) quantities. Here we propose a solution. Microspheres of black ceramic can be used as marker grains for a wide range of microfossil analyses (in this paper, however, we mainly discuss the use of the material for pollen analysis because of the expertise of the authors). The ceramic spheres are tolerant to all chemicals commonly used during pollen extraction processes and is extremely resistant to physical stresses. The particles are matt black, spherical, available in a wide range of size clusters, have a density very close to that of fossil pollen grains (1.424 g/cm3 vs. 1.494 g/cm3 in average), and don't change color and density over a long storage in acidic liquids. The behavior of ceramic spheres was closer to the pollen grains than the Lycopodium spores regardless of the pollen concentration and composition in sediments. In combination, these properties make the black ceramic spheres an even better solution for palynologists than DuPont NEM microbeads or Lycopodium spore tablets. The absolute pollen concentrations estimated from ceramic spheres and those estimated from volume method were indistinguishable within errors. On the other hand, when the samples were relatively poor in fossil pollen grains, the concentrations calculated by Lycopodium method tended to be significantly overestimated. The ceramic microbeads are available either as a dry powder in different size ranges, or as a mixture of two size ranges blended in a defined ratio and dispersed in a buoyancy-neutral liquid, ready to be added to sediment samples. Mixing two different size ranges in a known ratio serves to detect any laboratory failures that differentially favor recovery of larger or smaller pollen types.

Numerical investigation on inner particle effects in Lycopodium/Air dust deflagrations

Dust deflagration is a rapid combustion process with the spread of flame at subsonic speed. Standard numerical modelling approaches using pyrolysis/evaporation are neglecting phenomena determined by transport limitations inside the dust particle. Main objective of this paper is the investigation and understanding of relevant transport phenomena in the inner structure of a Lycopodium particle. This was achieved by three individual models. The first model describes the dust deflagration, using a flame speed approach. After the evaluation of model by the flame front propagation and associated temperature, data is used in a second model. This model uses Lagrangian tracer particles, placed in the flame front. The flame front is passing these particles, which are used for metering data, such as composition and temperature of the gas to calculate the heat transfer coefficient and the mass transfer coefficient of each species. These results are used as boundary conditions for the third model, a single particle model, which considers a mobile gaseous phase in the pores and a stationary phase for the solid and liquid substances by using a Eulerean approach. In addition, the gaseous phase includes heat and mass transport by convection and diffusion/conduction in the pores, whereas the stationary phase considers only heat conduction. The pyrolysis in this model includes the primary pyrolysis, the tar cracking and heterogeneous char reactions, as well as the set of homogenous reactions for the gas phase. With the single particle model four different geometries were observed: two 3D geometries with different lycopodium spores, a 1D radial symmetric geometry and a 0D geometry. All simulations are based on OpenFOAM 1.7.1.

Shedding light on sporopollenin chemistry, with reference to UV reconstructions

Sporopollenin, which forms the outer wall of pollen and spores, contains a chemical signature of ultraviolet-B flux via concentrations of UV-B absorbing compounds (UACs), providing a proxy for reconstructing UV irradiance through time. Although Fourier transform infrared (FTIR) spectroscopy provides an efficient means of measuring UAC concentrations, nitrogen-containing compounds have the potential to bias the aromatic and hydroxyl bands used to quantify and standardise UAC abundances. Here, we explore the presence and possible influence of nitrogen in UV reconstruction via an FTIR study of Lycopodium spores from a natural shading gradient. We show that the UV-sensitive aromatic peak at 1510cm−1 is clearly distinguishable from the amide II peak at 1550cm−1, and the decrease in aromatic content with increased shading can be reconstructed using standardisation approaches that do not rely on the 3300cm−1 hydroxyl band. Isolation of the sporopollenin results in the loss of nitrogen-related peaks from the FTIR spectra, while the aromatic gradient remains. This confirms the lack of nitrogen in sporopollenin and its limited potential for impacting on palaeo-UV reconstructions. FTIR is therefore an appropriate tool for quantifying UACs in spores and pollen, and information on UV flux should be obtainable from fossil or processed samples.

Evaluation of Spray and Point Inoculation Methods for the Phenotyping of Puccinia striiformis on Wheat

The fungus Puccinia striiformis causes yellow (stripe) rust on wheat worldwide. In the present article, new methods utilizing an engineered fluid (Novec 7100) as a carrier of urediniospores were compared with commonly used inoculation methods. In general, Novec 7100 facilitated a faster and more flexible application procedure for spray inoculation and it gave highly reproducible results for virulence phenotyping. Six point inoculation methods were compared to find the most suitable for assessment of pathogen aggressiveness. The use of Novec 7100 and dry dilution with Lycopodium spores gave an inoculation success rate of 100% in two independent trials, which was significantly higher and more consistent than for spore suspension in Soltrol 170, water, water + Tween 20, and Noble agar + Tween 20. Both Soltrol 170 and Novec 7100 allowed precise quantification of inoculum, which is important for the assessment of quantitative epidemiological parameters. New protocols for spray and point inoculation of P. striiformis on wheat are presented, along with the prospect for applying these in rust research and resistance breeding activities.

Determining the absolute abundance of dinoflagellate cysts in recent marine sediments III: Identifying the source of Lycopodium loss during palynological processing and further testing of the Lycopodium marker-grain method

Lycopodium clavatum marker-grain tablets are often added before palynological processing to calculate the absolute abundance of organic-walled microfossils in sediments. In this study we investigate the reproducibility of dinoflagellate cyst concentrations by performing nine different tests: varying dinoflagellate cyst/Lycopodium spore ratios, sample weights, centrifuge speeds and times, sonication times, and mesh sizes; manually powdering the sediment using a mortar and pestle prior to processing, using a water jug instead of squirt bottles during sieving, decanting over a 6 μm sieve and adding Lycopodium tablets at the end. Previous studies have reported loss of Lycopodium spores during processing. In this study we investigate sources of this loss by microscopically analyzing residue on stir sticks and sieves, and what is lost through the sieves and decanting. We document an average loss of 8.2 % of Lycopodium spores during processing, with the greatest loss occurring through the fine sieve and resulting in only a 4.8% overestimation of the cyst concentration. Results using powdered sediment and sonicating for more than 5 min are less reproducible. Large cyst/Lycopodium spore ratios were found to have higher cyst concentrations and standard deviations, thus we recommend ratios of less than five, and ideally ratios between 0.5 and 2 to facilitate counting.

Coupled resonances allow studying the aging of adhesive contacts between a QCM surface and single, micrometer-sized particles

Interparticle contacts and contacts between particles and surfaces are known to change over time. The contact area, the contact stiffness, and the contact strength usually increase as the contact ages. Contact aging is mostly driven by capillary forces, but also by plastic deformation. Making use of acoustic resonators, we have studied the stiffness of contacts between the surface of a quartz crystal microbalance (QCM) and individual, micrometer-sized particles adsorbed to the resonator surface. Studying single particles avoids ensemble-averaging. Central to the analysis is the coupled resonance, occurring when a surface-attached particle together with the link forms a resonator of its own. If the frequency of this second resonator comes close to one of the crystal’s overtones, plots of shifts in resonance bandwidth versus overtone order display a resonance curve. This secondary resonance is caused by the coupling between the particle’s resonance and the main resonance. One can read the frequency of the coupled resonance from this plot. Similarly, resonance curves are observed in plots of frequency and bandwidth versus time, if the contact stiffness varies smoothly with time. Because the coupled resonance is a characteristic feature, it is easily identified even in cases where frequency shifts of some other origin are superimposed onto the data. For the cases studied here, the links stiffened while they dried. Interestingly, the efficiency of coupling between the particle resonance and the main resonance decreased at the same time. This can be explained with an increase in the link’s bending stiffness. The analysis highlights that a QCM experiment amounts to vibrational spectroscopy on surface-attached particles. Among the application examples is the adsorption and drying of a lycopodium spore. Clearly, the technique is also applicable to problems of bioadhesion.

Electrostatic Charge on Flying Hummingbirds and Its Potential Role in Pollination.

Electrostatic phenomena are known to enhance both wind- and insect-mediated pollination, but have not yet been described for nectar-feeding vertebrates. Here we demonstrate that wild Anna's Hummingbirds (Calypte anna) can carry positive charges up to 800 pC while in flight (mean ± s.d.: 66 ± 129 pC). Triboelectric charging obtained by rubbing an isolated hummingbird wing against various plant structures generated charges up to 700 pC. A metal hummingbird model charged to 400 pC induced bending of floral stamens in four plants (Nicotiana, Hemerocallis, Penstemon, and Aloe spp.), and also attracted falling Lycopodium spores at distances of < 2 mm. Electrostatic forces may therefore influence pollen transfer onto nectar-feeding birds.

Sag in drying coatings: Prediction and real time measurement with particle tracking

Sag is a coating phenomenon characterized by gravity-driven flow after deposition; excessive amounts of sag can lead to coating defects. In this work, a new method for evaluating and quantifying sag is investigated. The motion of micron-sized Lycopodium spores on an inclined coating surface is tracked during drying, and the resulting surface velocity data is used to determine sag length. This in situ particle tracking method is minimally invasive and permits real time measurements. Measured sag lengths and real time surface velocities in aqueous polyvinyl alcohol solution coatings compare well with a theoretical model. The model is also used to develop a predictive sag regime map, which anticipates the extent of sag given coating properties and process-specific parameters. This map also identifies viable processing windows and aids in intelligent coating design given specific process constraints. The predictions of the sag regime map are compared against experimental sag results from polyvinyl alcohol solution coatings as well as four commercial latex paints, revealing good agreement for coatings with Newtonian or ‘Newtonian-like’ rheologies.

The impact of oxidation on spore and pollen chemistry

Sporomorphs (pollen and spores) have an outer wall composed of sporopollenin. Sporopollenin chemistry contains both a signature of ambient ultraviolet-B flux and taxonomic information, but it is currently unknown how sensitive this is to standard palynological processing techniques. Oxidation in particular is known to cause physical degradation to sporomorphs, and it is expected that this should have a concordant impact on sporopollenin chemistry. Here, we test this by experimentally oxidizing Lycopodium (clubmoss) spores using two common oxidation techniques: acetolysis and nitric acid. We also carry out acetolysis on eight angiosperm (flowering plant) taxa to test the generality of our results. Using Fourier Transform infrared (FTIR) spectroscopy, we find that acetolysis removes labile, non-fossilizable components of sporomorphs, but has a limited impact upon the chemistry of sporopollenin under normal processing durations. Nitric acid is more aggressive and does break down sporopollenin and reorganize its chemical structure, but when limited to short treatments (i.e. ≤10 min) at room temperature sporomorphs still contain most of the original chemical signal. These findings suggest that when used carefully oxidation does not adversely affect sporopollenin chemistry, and that palaeoclimatic and taxonomic signatures contained within the sporomorph wall are recoverable from standard palynological preparations.

Modern Pollen Distribution at İğneada Waterlogged Forests Between the Periods September 2007 – August 2009

Study has been worked to find out arboreal and non-arboreal pollen influx (cm2/mo) fallen to the ground and relations between striking meteorological parameters at Kırklareli-Igneada waterlogged forests 6 plots between 2007-2009 where significantly high vegetation diversity was provided. Tauber style pollen traps have been installed into the 6 field plots and were replaced monthly. The pollen traps transferred to the laboratory Lycopodium spore tablets were used in accordance with European Pollen Monitoring Program and pollen slides were prepared. The annual pollen influx of Carpinus sp., Fraxinus sp., Hedera helix , Alnus sp., Corylus sp., Acer sp., and Quercus sp. was higher respectively between the period 2007 and 2009. Also, the annual pollen influx of Poaceae, Chenopodiaceae, Plantago sp., and Ambrosia sp. was higher respectively for the same period. Pollen influx increase significantly along open field conditions and forest canopy for herbaceous plant and arboreal plants respectively. Pollen density was lower at the period between 2008 and 2009 due to higher rain. Keywords: Igneada waterlogged forest, Tauber style pollen trap, Lycopodium , pollen influx.

Characterization of the Magnetism of Lycopodium Spores

The magnetic properties of Lycopodium powders from two different sources are investigated. In addition to a characteristic diamagnetism with χ = -8(1) × 10 -6 , there is a Curie-law paramagnetism, which is the dominant contribution to the susceptibility below 20 K, and an additional weak hysteretic signal with a saturation magnetization of magnitude 0.6-1.8 × 10 -3 Am 2 kg -1 at room temperature. After ignition of the powder, the remaining inorganic ash represents just 1.05% of the original mass, but the room temperature magnetization increases only by a factor of 5. The iron content of the Lycopodium, deduced by chemical analysis of the ash is 43-76 ppm. Of this, roughly 3/4 is paramagnetic, and 1/4 is in the form of magnetite.