Pollen segmentation and feature evaluation for automatic classification in bright-field microscopy

14 págs.; 10 figs.; 7 tabs.; 1 app.© 2014 Elsevier B.V. Besides the well-established healthy properties of pollen, palynology and apiculture are of extreme importance to avoid hard and fast unbalances in our ecosystems. To support such disciplines computer vision comes to alleviate tedious recognition tasks. In this paper we present an applied study of the state of the art in pattern recognition techniques to describe, analyze, and classify pollen grains in an extensive dataset specifically collected (15 types, 120 samples/type). We also propose a novel contour-inner segmentation of grains, improving 50% of accuracy. In addition to published morphological, statistical, and textural descriptors, we introduce a new descriptor to measure the grain's contour profile and a logGabor implementation not tested before for this purpose. We found a significant improvement for certain combinations of descriptors, providing an overall accuracy above 99%. Finally, some palynological features that are still difficult to be integrated in computer systems are discussed.This work has been supported by the European project APIFRESH FP7-SME-2008-2 ‘‘Developing European standards for bee pollen and royal jelly: quality, safety and authenticity’’ and we would like to thank to Mr. Walter Haefeker, President of the European Professional Beekeepers Association (EPBA). J. Victor Marcos is a ‘‘Juan de la Cierva’’ research fellow funded by the Spanish Ministry of Economy and Competitiveness. Rodrigo Nava thanks Consejo Nacional de Ciencia y Tecnología (CONACYT) and PAPIIT Grant IG100814.Peer Reviewe

Complete determination of plant tissues based only on auto-fluorescence and the advanced image analysis – study of needles and stamens

Finding the procedure for proper tissue determination is a challenging task in various fields of biology and medicine, unfortunately often affected by subjectivity of the histologist. We have introduced the method based on L0-norm constrained nonnegative matrix factorization and compared it with several algorithms on controlled, simulated set of images. The key advantage is the ability to extract much more components from the starting set of images (often small number) in comparison to other methods, providing more versatile set of parameters for tissue classification

EVOLUTION OF LAKE ERIE BASED ON THE POSTGLACIAL SEDIMENTARY RECORD BELOW THE LONG POINT, POINT PELEE, AND POINTE-AUX-PINS FORELANDS

The postglacial geological history of Lake Erie was interpreted primarily on the basis of borehole sedimentary sequences below the major accretionary forelands: Long Point, Point Pelee, and Pointe-aux-Pins. These data were complemented by a number of sedimentary profiles from other boreholes in and around the lake, radiocarbon and pollen-based dating of postglacial sediments, relic geomorphological features, and geometrical and sedimentary data from inflowing streams. Trends in sediment properties in the basal portion of the sequences consistently show an abrupt change from glacial sediments (Unit 1), topped by an eroded surface, possibly sub-aerially exposed, to postglacial silty clays deposited in deep- or quiet-water environments (Unit 2). As topographic lows were infilled and water depths decreased, the mean grain size increased, reflected in an increasing frequency of sandy laminations (Unit 3). This transitional unit is usually topped by an erosional unconformity, suggesting non-deposition and reworking prior to the deposition of well-sorted, medium sand (Unit 4) at the top of the sequence. Deposition of the top unit began around 5000 years B.P., and clearly occurred in an upper shoreface setting where saltation and bottom traction were the predominant transport modes. This change probably marks the initiation of spit formation at the sites. All boreholes exhibit a clear coarsening-upward textural trend, suggestive of lateral migration of the higher-energy upper shore face (spit) facies over lower shoreface and lagoonal facies. Combined with the radiocarbon dates and other data, the above sediment interpretation suggests important revisions to earlier interpretations of postglacial lake levels in the Lake Erie basin. Moreover, the lake level curve presented here confirms glacioisostatic rebound of the lake outlet as a major factor in the initial lake level trend, but it also suggests that other processes (such as the changing pattern of inflows from the Upper Great Lakes, the nature and postglacial tectonics of the lake outlet, and paleoclimatic influences) could have become important in the later stages. The above data were used in a hypothetical reconstruction of Lake Erie paleogeography, including the three major forelands of the north shore. The inferred form of the contemporary shoreline, and the evolutionary trends indicated by beach-ridge patterns on the forelands themselves, suggest that these forelands did not result from conventional spit formation. Rather, their origin is due primarily to the effectiveness of cross-lake moraines in Lake Erie as sand-accumulation sites. The evolution of the forelands over the past 3000 years involves persistent erosion and shoreward transgression under the influence of rising lake levels, in a manner analogous to the ongoing retreat of barrier islands on marine coasts

Sedimentology of the Paleogene succession at Calypsostranda, Svalbard

The following study encompasses sedimentological investigations of the Calypsostranda Group. The Calypsostranda Group is comprised of Paleogene sediments where outcrops are well exposed in a coastal section at Renardodden (Calypsostranda area), on the southern shores of Bellsund in western Spitsbergen. The aim of the study is to: i) generate reliable depositional models for the evolution of the sediments of the Calypsostranda Group, through facies recognition and break-down ii) investigate and discuss source-to-sink perspectives including provenance and possible basin-development scenarios in accordance with different age datings and the tectonic history of western Spitsbergen. A limited amount of research has been conducted on the deposits of the Calypsostranda Group, however they are important to understand in the context of the regional sedimentation and tectonic history of western Spitsbergen. The succession encompasses delta plain sediments of the Skilvika Formation and paralic to marine sediments of the Renardodden Formation. Through sedimentological outcrop investigations, sixteen lithofacies have been identified from the studied sedimentary succession of the Calypsostranda Group (F1-F16) by means of facies recognition and break-down. The lithofacies were further grouped into seven sub facies associations, which can be divided into two main facies associations: i) a sub-aerial delta plain (Skilvika Formation) and ii) a paralic to marine regime (Renardodden Formation). The deposits in the Calypsostranda area were initially deposited in a prograding fluvial dominated, storm-wave influenced delta system. The fluvial dominance can be deduced from a number of observations; the abundancy of distributary channels on the delta plain, coarse-grained debris flow deposition from hyperpycnal flows on the delta front, mouth bar deposits and turbidites. The dominance of very-fine to fine-grained sand and abundancies of coal fragments in the marine deposits are indicators of a fluvial dominated system. The deposits have further been divided into a five-stage depositional model that involves a major transgressive phase drowning previously subaerial deposits, followed by normal regression with delta progradation. Evidence from the petrographical and sedimentological analysis points to a potential dual source area for the deposits in the Calypsostranda area. Findings of metasedimentary rock fragments, silica-rich biofragments and chloritoid in the thin sections account for a potential metamorphic basement derived source. In addition, a sand-rich system and coal fragments suggests an uplifted sedimentary source. Given the uncertainty of the ages of the deposits, three different palaeogeographical scenarios are presented and described.Masteroppgave i geovitenskapGEOV39

River planform, soil stratigraphy and the temporal and palaeoenvironmental significance of terraced valley fill deposits in upland Scotland, with specific reference to Glen Feshie, south-west Cairngorms

River terraces form prominent features of the valley floor morphology of many upland valleys in Scotland. Little is known, however, about valley floor landform development in many of these valleys. Previous studies have generally explained the terraces as the outwash products of meltwaters from the most recent cold periods. Detailed investigation of a major valley in the Scottish Highlands challenges, for at least one site, this well established concept and proposes the occurrence of at least three phases of Holocene terrace development.The correlation of terrace surfaces has traditionally been based upon the construction of height-range diagrams. An alternative approach to terrace correlation and dating is developed in this study using data from Glen Feshie, south-west Cairngorms. Terrace fragments are numerically classified and objectively grouped using quantitative soil-stratigraphic data. Principal Components Analysis and a hierarchical clustering technique numerically define five soil-stratigraphic units and place these on a relative time scale. Various methods of absolute dating control permit association of these units with five phases of terrace development. These are placed at 13,000, 10,000, 3,600, 1,000, 80, radiocarbon years BP.Comparison of palaeochannel networks preserved on the terrace surfaces suggests that these phases of terrace development have been associated with changes in channel pattern morphology. A unified approach to analysis of channel pattern morphology is developed and from this a new technique for palaeohydrological interpretation of gravel-bed streams. A segment density index is developed which allows total sinuosity to be predicted from just a part of the braided channel network. Application of these techniques to the Glen Feshie terraces demonstrates a trend for an overall decrease in discharge from the oldest terrace surfaces to the present day.Assessment of these landform changes within the context of known environmental fluctuations in the Cairngorms suggests that the early-mid Holocene was a period of relative landscape stability while the late Holocene was characterised by increasing instability. These changes may have been associated with the changes in river behaviour. However, spatial variation in the depth of the fill/bedrock interface may produce a discontinuous river response to changing environmental conditions

Quaternary Geomorphology of the Quebec North Shore, Godbout to Sept-Iles

This report presents a summary of the physical properties of surficial deposits, evolution of the landscape and economic aspects of the materials. Surficial geology maps of the Sept-Iles and Cap Chat map sheets, at a scale of 1:125,000, accompany the text. The work was carried out by field investigations and air photo interpretation, combined with laboratory analyses of samples collected. The Quaternary deposits of the North Shore are the product of the last glacial episode and postglacial processes. The main materials are gravelly till and outwash, estuarine nearshore deltaic sand and offshore clay, littoral sand, aeolian sand, peat and alluvium. Evidence from striae and flutings, indicator mineralogies and till fabrics indicates that the main direction of ice flow was towards the south-southeast over the entire area, although there is evidence of an earlier and a very late easterly flow along portions of the south coast adjacent to the Laurentian Trough. Deglaciation occurred about 10,000 years ago at Sept-Iles. The marine limit is at an elevation of 130 min that area but declines towards the southwest to 100 mat Godbout. From the time of deglaciation the landscape above the marine limit was altered by the deposition of a thin layer of gravelly granitic till as the ice sheet retreated northward. A belt of moraines extending across the field area from the Toulnustouc River to the Moisie River marked interruptions in the retreat. Below the marine limit the landscape evolved through the deposition of a marine offlap sequence. Large coalescing deltas were built into the Goldthwait Sea during the first 1500 years after deglaciation. Rock flour was carried out into the offshore environment and was deposited as banded or massive silty clay. Landslides occur where these deposits are presently found at, or near, the surface. A tentative correlation of events and materials has been suggested by comparing the results of this study with those in other areas of the Gulf of St. Lawrence, the St. Lawrence Lowlands, and the Labrador Plateau. Direct correlation is difficult because of the large distances involved and the shortage of chronological control on the North Shore. The morainic belt is directly linked to moraines reported to the west and east of the field area

Eruption dynamics and frequency-magnitude relationships of explosive eruptions at Mt. Ruapehu, New Zealand over the past 1800 years : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Earth Science at Massey University, Palmerston North, New Zealand

Appendices A-I (listed on pp. 259-261) have not been included in the thesis, but may be consulted by contacting the author at [email protected] to moderate explosive eruptions (VEI ≤ 3) constitute the most frequent eruptions and often involve several phases characterised by different eruption dynamics. Deposits associated with small-scale multi-phase eruptions tend to be underrepresented in geological records and the resulting probabilistic eruption forecast models. This PhD research presents a refined high-resolution tephrostratigraphic framework for the 1800-year Tufa Trig Formation at one of New Zealand’s most active volcanoes, Mt. Ruapehu. This framework is used to characterise short- and long-term changes in eruption behaviour aiming to identify time-variable processes in the volcanic system of a long-lived andesite volcano. Systematic mapping and lithosedimentological characterisation of tephra deposits are combined with geochemical fingerprinting and radiocarbon dating to create a detailed frequency-magnitude record of single- and multi-phase eruptions of the last 1800 years. At least 32 eruptions can be identified, ranging from low to mid-intensity single-phase eruptions (1–10 × 10⁶ m³ deposit volumes) to complex multi-phase eruptions up to two magnitudes larger. The largest eruption is the T13-sequence that comprises at least 5 eruption phases. Multi-lobate dispersal pattern and componentry analyses show that individual eruption phases represent multiple fall events of similar eruption style and magnitude. Major and trace element analyses of juvenile glass display limited syn-sequence variability, while heterogeneous pyroclast and textural characteristics suggest that short-term changes in eruption behaviour are predominantly controlled by shallow conduit processes. The frequency-magnitude record is integrated with geochemistry and statistical modelling, identifying time-variable pattern in Mt. Ruapehu’s eruption behaviour: the time span 1718–1300 cal BP involves low-intensity single-phase eruptions every ~40 years and is followed by a low rate regime (one eruption every 125 years). The largest multi-phase eruptions of the last two millennia occur between 610 and 370 cal BP, while the past 370 years are dominated by smaller multi-phase eruptions every ~40 years, suggesting that long-term changes in Mt. Ruapehu’s eruption behaviour are related to changes in magma supply. This research adds critical complexity to the understanding of the processes and timescales controlling eruption behaviour in the southern Taupo Volcanic Zone and provides insights into the dynamic behaviour of small to moderate multi-phase eruptions. These results will constitute the framework for refining dynamic eruption forecast models at Mt. Ruapehu and other similar volcanoes globally