bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modified combination of platelet count and neutrophil “to” lymphocyte ratio as a prognostic factor in patients with advanced head and neck cancer
Authors: Nakayama Masahiro , Gosho Masahiko , Hirose Yuki , Nishimura Bungo , Tanaka Shuho , Tabuchi Keiji , Okubo Hideki , Wada Tetsuro , Hara Akira 
Published: January 2018

AbstractBackgroundWe evaluated the prognostic potential of the combination of platelet count and neutrophil to lymphocyte ratio (COP‐NLR) in patients with advanced head and neck cancer.MethodsWe proposed a modified COP‐NLR scoring system defined as follows: score 0 (platelet count level <300 × 109/L and NLR <3); score 1 (platelet count level ≥300 × 109/L and NLR <3); and score 2 (NLR ≥3). We assessed whether the modified scoring system had better performance as an indicator of prognosis than the existing COP‐NLR scoring system (original and 4‐group scores).ResultsA total of 248 patients were enrolled. The Akaike Information Criterion value with the modified COP‐NLR score was the smallest among the 3 models. The 3‐year survival rates according to the modified COP‐NLR scores of 0, 1, and 2 were 80.6%, 59.9%, and 23.8%, respectively.ConclusionThe modified COP‐NLR score is a useful prognostic marker in patients with advanced head and neck cancer.
ADVENTITIOUS ROOT DEVELOPMENT FROM THE COLEOPTILAR NODE IN ZEA MAYS L.
Authors: Martin Elizabeth M. , Harris William M. 
Published: January 2018

Department of Botany and Bacteriology, University of Arkansas, Fayetteville, Arkansas 72701Zea mays L. root development from the coleoptilar node was observed by light and electron microscopy. Roots developed opposite collateral vascular bundles in the coleoptilar nodal region. Three distinct histogens (stelar, cortical‐protoderm, and root cap) became evident in early development. In median sections of the young roots, root cap and cortical regions formed a “hat” configuration over the stelar region. As the root matured, this “hat” developed centripetally to encapsulate the stelar region. Central core cells of the root cap were characterized by having numerous dictyosomes, amyloplasts, vacuoles, and thin cell walls. As these cells matured into outer or peripheral cap cells, the Golgi vesicles became hypertrophied. These hypertrophied vesicles contained a granular PAS‐positive material which accumulated between the plasma membrane and the cell wall and formed a thick layer. As the PAS‐positive material passed through the cell wall, it changed to a fibrillar texture. A PAS‐positive material similar to that in the outer root cap cells was found adjacent to the outer walls of the protodermal cells. In median sections, PAS‐positive material was not present in the promeristem region. Root cap cells as well as parent cortical cells were crushed as the young root forced its way through the parent tissue.
MICROSPOROCYTE GROWTH AND MEIOSIS IN PHYLLOSPADIX TORREYI, A MARINE MONOCOTYLEDON
Authors: Stewart J. G. , Rüdenberg L. 
Published: January 2018

In this paper we demonstrate spindle rotation during meiosis in filiform microsporocytes of a dioecious marine monocotyledon.Extensive populations of Phyllospadix torreyi, a seagrass, cover intertidal and shallow subtidal rocks in southern California. Flowering plants are unevenly distributed, being found only in patches within these beds, and apparently are disproportionally few relative to plants that do not produce flowers. Reduction division in male flowers occurs in an already elongate microsporocyte (pollen mother cell), where the chromosomes at metaphase lie in a plane across the narrow axis of the filamentous cell. However, the poles and spindles then rotate through 90° during anaphase of first and second meiotic divisions so that the cells divide longitudinally to produce tetrads which develop into filamentous pollen. Nine bivalents were counted in diakinesis figures. The presence of a heteropycnotic X‐chromosome in male flowers is suggested by certain observations of prophase‐anaphase figures.
THE BALANCE OF FORCES GENERATED BY THE WATER POTENTIAL IN THE CELL‐WALL‐MATRIX—A MODEL
Authors: McClendon John H. 
Published: January 2018

A cell in contact with air is considered. The nature of the water within a cell wall is assumed (with citations in support) to be that of free water and essentially free of diffusible solutes, so that the air‐water interface generates negative pressures (Pf) (at all relative humidities less than 100%), equal to the overall cell‐water‐potential. At the inner wall‐surface, the turgor pressure (Pt) is balanced by the sum of Pf and a pressure resisting collapse of the wall matrix (Psi); at the outer wall‐surface, Pf is balanced only by a similar pressure (Pso). Under all circumstances, Psi = Pt – Pf, and the osmotic term of the internal cell‐water‐potential (Ψis) = –Psi. At full turgor, Pso is zero, and it rises as water is lost, equalling Psi when Pt is zero (Psi = –Pf).In cells in contact with solutions of solutes which penetrate the wall, Pf and Pso are zero and Psi follows Pt.In either case, the hoop stress, tending to enlarge the cell surface, is proportional to Pt, but the cell‐in‐contact‐with‐air has radial stresses not found in submerged cells.The nature of the forces resisting radial compression of the wall is discussed, and thought to be a combination of mechanical elastic forces and osmotic forces due to non‐diffusible polysaccharides of the wall.
DIFFERENTIAL PRESERVATION OF PROTOPLASM IN FOSSIL ANGIOSPERM LEAF TISSUES
Authors: Niklas Karl J. 
Published: January 2018

Examination of Miocene angiosperm leaf compressions from the Clarkia and Succor Creek localities of Idaho and Oregon reveals a characteristic and predictable pattern of protoplasmic deterioration. Remnants of chloroplasts are preserved in 63.9% of the 8,800 randomly selected cells, while mitochondria (18.6%) and nuclei (11.3%) are less commonly preserved. This pattern appears to be independent of the presumed environment of deposition associated with fossilization. Leaf tissues from sediments thought to be derived from shallow and deeper waters of the Miocene Clarkia lake (Chloro = 34.6%, Mito < 3%, Nuc < 1% and Chloro = 90.1%, Mito = 26%, Nuc = 4.3%, respectively) show similar patterns of ultrastructural preservation to leaves preserved in volcanic ash‐fall deposits (Chloro = 80%, Mito = 45.4%, Nuc = 39.5%). Analyses of the data for the relative abundance of various organelles per cell (e.g., in living plants Chloro/Nuc = 250) in fossil tissues and referable modern taxa indicate that the chances of the observed preferential degradation of nuclei being the results of chance is <0.001.The data are interpreted to be evidence for the preferential preservation of chloroplasts and degeneration of nuclei. The pattern of protoplasmic degeneration, reconstructed from the frequencies of organelle preservation, is in contrast to that of the pattern observed in modern plant cell necrosis or senescence where nuclei are the most stable organelle and persist until the death of the cell. Preliminary data indicate that regimes of dehydration and compression may duplicate the pattern of protoplasmic degeneration observed in fossil plant cells.
CHEMICAL AND PHYSICAL CHARACTERISTICS OF SHALLOW GROUND WATERS IN NORTHERN MICHIGAN BOGS, SWAMPS, AND FENS
Authors: Schwintzer Christa R. , Tomberlin Thomas J. 
Published: January 2018

Fifteen chemical and physical characteristics were examined in samples of shallow ground water taken in midsummer at 15‐30 cm below the surface in six bogs, 15 swamps, and six fens. The wetland types were identified on the basis of their vegetation. Three groups of covarying water characteristics were identified by factor analysis. Factor I included Ca, Mg, Si, pH, alkalinity, conductivity and to a much lesser extent Na, and reflects the degree of telluric water influence in the wetland. Factor 2 included reactive‐P, total‐P, NH3‐N, and to a lesser extent K, and consists of elements that primarily enter interstitial water via organic matter decomposition. Factor 3 included Na, Cl, and to a much lesser extent K.The wetlands formed two distinct groups with respect to water chemistry: weakly minerotrophic (pH 3.8‐4.3) including all bogs and moderately to strongly minerotrophic (pH 5.5‐7.4) including all swamps and fens. The bogs had very low values for Factor 1 characteristics and moderate values for the remaining characteristics. The swamps and fens had moderate to high values for Factor 1 characteristics and showed considerable overlap in this respect. The fens had consistently low values for Factor 2 characteristics but overlapped with some swamps which also had low Factor 2 scores. Failure to completely separate the vegetationally very distinct swamps and fens from each other on the basis of their physical and chemical water characteristics indicates that another factor, probably water level regime, is of major importance in determining their vegetation type.
IMPERMANENT INITIALS OF THE SHOOT APEX AND DIPLONTIC SELECTION IN A JUNIPER CHIMERA
Authors: Ruth Jennifer , Klekowski Edward J. , Stein Otto L. 
Published: January 2018

Shoot meristems of Juniperus davurica cv. Expansa Variegata possess an apical zonation pattern similar to that found in some angiosperms. Anticlinal divisions predominate in the outer layer, the tunica. The underlying core of cells, the corpus, has cell divisions oriented in all directions. Typically, this variety exists as a periclinal chimera, the outer layer genotypically albino and the inner core composed of normal, chlorophyll‐producing cells. In this condition a shoot appears green. Occasionally a tunica cell divides periclinally and displaces an initial in the apical region of the corpus. This event subsequently is expressed during ontogeny as an albino sector on the stem and leaves.Frequent variation in the width of an albino sector throughout ontogeny suggests a temporary nature of cells in the position of apical initials. A correlation was documented between the position of axillary bud release and a subsequent increase or decrease in the width of an albino sector. A model based upon stochastic processes and diplontic selection is proposed to account for the dynamic nature of chimeric patterns observed in this plant.
XYLEM STRUCTURE IN BOTRYCHIUM DISSECTUM SPRENGEL AND ITS RELEVANCE TO THE TAXONOMIC POSITION OF THE OPHIOGLOSSACEAE
Authors: Chau Robert I. 
Published: January 2018

The radially seriate xylem of Botrychium dissectum Sprengel resembles secondary xylem, particularly that of gymnosperms, in many important details. It is derived from a layer of cells which strongly resembles a vascular cambium. Presumptive cambial initials are fusiform, and derivatives are radially seriate. The walls of the initials and derivatives have a beaded appearance when viewed in tangential section. The number of xylem elements increases in seasonal increments. Circular‐bordered pit pairs occur where tracheids abut other tracheids, and specialized cross‐field pit pairs occur where they abut the radially‐aligned parenchyma or rays.Cambial activity in Botrychium differs from that found in seed plants and progymnosperms in not producing secondary phloem. Tracheids are less similar to those known in progymnosperms than previously assumed, and some supposed similarities may be less significant than previously assumed. The significance of these dissimilarities is unclear. The recognition that the bulk of the xylem is secondary and that protoxylem strands are arranged as sympodia suggests that Botrychium may be eustelic rather than siphonostelic.
DINITROGEN FIXATION BY CYANOBACTERIA AND ASSOCIATIVE RHIZOSPHERE BACTERIA IN THE ARAPAHO PRAIRIE IN THE SAND HILLS OF NEBRASKA
Authors: Kapustka Lawrence A. , DuBois John D. 
Published: January 2018

Free‐living and lichenized cyanobacterial (cyanolichen) colonies occupy 12–29% of the surface area in the Sand Hills grasslands on the Arapaho Prairie in southwestern Nebraska. During brief periods of favorable conditions (i.e., moderate temperature and high moisture), these diazotrophs are capable of high rates of dinitrogen fixation. Maximum rates of acetylene reduction measured during 1981 and 1982 were 2,237 μg N m‐2 hr‐l. The duration of dinitrogen fixation activity is dependent upon moisture conditions; rates of acetylene reduction were shown to decline 90% in as little as three hr. Desiccated colonies resumed acetylene reduction activity within one hr and achieved equilibrium rates within four hr following rehydration.Associative, heterotrophic diazotrophs were isolated from the rhizospheres of several grass species. These bacteria exhibited a range of culturing characteristics which may reflect differing plant‐bacterial interaction potentials important to the establishment and maintenance of the plant species. None of the field assays for heterotrophic dinitrogen fixation performed over the two‐yr period indicated a capacity of this group to provide ecologically significant levels of N in this grassland.Our gross estimate of the annual contribution was 3.5 kg N ha‐1 from cyanolichens and 0.8 kg N ha‐1 from associative heterotrophs.
DIFFERENTIAL GERMINATION OF RAY AND DISC ACHENES IN HEMIZONIA INCRESCENS (ASTERACEAE)
Authors: Tanowitz Barry D. , Salopek Paul F. , Mahall Bruce E. 
Published: January 2018

The differential germination responses of ray and disc achenes of Hemizonia increscens (Asteraceae) were compared in field and laboratory investigations in order to gain insight into the ecological and evolutionary significance of heterocarpy.In the field, 200 ray and 200 disc achenes were placed in native, sterilized soil in a series of cleared, randomized, replicated plots. In a nearby plot a similar number of achenes were placed in plastic petri dishes in which high moisture conditions were maintained. Disc achene germination occurred under relatively minimal moisture conditions (<1 cm rainfall for 19 days) and relatively mild temperature regimes (21–7 C). Disc achene germination began three days after planting in the field plot and four days after they were put into the field petri dishes. In contrast, the onset of ray achene germination occurred 21 days after planting in the field plot and 19 days after planting in the field petri dishes. Averages of 2.05 and 2.71 disc achenes/day germinated in the field plot and field petri dishes, respectively. These contrasted with averages of 0.57 and 0.50 ray achenes/day germinated in the field plot and in the field petri dishes, respectively. A total of 67.5% and 69% disc achenes germinated in the field plot and the field petri dishes, but only 18% and 16.5% ray achenes germinated in the field plot and field petri dishes, respectively.Three separate treatments, using 100 ray and 100 disc achenes in each, were performed in laboratory growth chambers: 1) nicking the fruit coat, 2) excising the embryo, and 3) leaving the fruit coat intact. Onset of germination for all disc achene treatments occurred after three days. No significant differences were found among the three disc achene treatments in timing, rate, or germination percentage. All three disc treatments in the laboratory closely paralleled those for disc achenes in the field plots in time and germination percentage, but rates of germination were not as high. Germination of the nicked and excised ray achenes treatments began after four days, while germination of the untreated ray achenes began after 27 days. Untreated ray achenes in the laboratory paralleled the ray achenes in both field experiments in rate and germination percentage, but were delayed in time of germination. The nicked and excised ray achene treatments, however, were similar to the disc achene treatments in time of germination, and were not significantly different from disc achenes in rate of germination. These data suggest 1) that ray and disc achenes are markedly different in germination under identical conditions in field and laboratory experiments, and 2) this difference in germination response may be due to the thicker pericarp of the ray achenes.
DYNAMICS OF POLLEN TUBE GROWTH IN THE WILD RADISH RAPHANUS RAPHANISTRUM (BRASSICACEAE). II. MORPHOLOGY, CYTOCHEMISTRY AND ULTRASTRUCTURE OF TRANSMITTING TISSUES, AND PATH OF POLLEN TUBE GROWTH
Authors: Hill Jeffrey P. , Lord Elizabeth M. 
Published: January 2018

The relative importance of prezygotic mechanisms of gametophytic competition and selection are often unclear due to an absence of observations on the gynoecium and pollen tube growth in vivo. We used LM, SEM, and TEM to study the structure of the gynoecium and the path of pollen tube growth in Raphanus raphanistrum, a sporophytically self‐incompatible annual.Wild radish has a papillate stigma and a solid style. A septum, which is characteristic of cruciferous gynoecia, is present in the ovary. After germination on the stigma, pollen tubes grow in the secretion of the transmitting tract of the style. The stylar secretion stains positive for acidic polysaccharides and insoluble carbohydrates, and negative for lipids and protein. In the ovary, the transmitting tissue is contained inside the septum. The secretion in the ovary stains positive only for acidic polysaccharides. Pollen tubes travel inside the septum as they enter the ovary and must exit to the surface of this tissue before ovule fertilization can occur. Pollen tube growth on the septum tracks the intercellular junctions of the septum epidermis where the secretion leaks out through a torn cuticle. Tubes must grow across the obturator before reaching the micropyle of an ovule. The temporal pattern with which tubes growing into the ovary exit the septum can contribute to the previously observed nonrandom patterns of fertilization (Hill and Lord, 1986).
MICRODISTRIBUTION OF THE BEACH PLANT CAKILE MARITIMA (BRASSICACEAE) AS INFLUENCED BY A RODENT HERBIVORE
Authors: Boyd Robert S. 
Published: January 2018

The microdistribution of a beach plant, Cakile maritima, was examined relative to patches of an introduced beachgrass, Ammophila arenaria. Sampling was done with belt transects oriented parallel to the beachfront to minimize the influence of physical factors along the land/sea gradient. No Cakile individuals were found within Ammophila patches, and a 3–4 m wide zone of decreased abundance occurred outside of patch borders.I hypothesized that this microdistribution was due to foraging behavior of deer mice, Peromyscus maniculatus, which nest in Ammophila patches and forage outward from them. Manipulative experiments using fruits and seedlings of Cakile confirmed that herbivory was higher inside patches and in border areas. Seedlings protected from herbivory by wire cages survived and grew equally well both inside and outside of Ammophila patches, demonstrating that differences in other habitat factors were not of major importance in determining Cakile microdistribution. Herbivory by mice was concluded to be of primary importance in determining the microdistribution of Cakile relative to Ammophila. Rodent herbivory may influence microdistributions of beach plants along the land/sea gradient, and may also be partly responsible for decreased plant species richness often observed in Ammophila‐dominated areas on the West Coast.
FACILITATION OF SUCCESSION BY THE NONMYCOTROPHIC COLONIZER SALSOLA KALI (CHENOPODIACEAE) ON A HARSH SITE: EFFECTS OF MYCORRHIZAL FUNGI
Authors: Allen Edith B. , Allen Michael F. 
Published: January 2018

The effects of inoculation with vesicular‐arbuscular mycorrhizal fungi on nonmycotrophic (plants which do not form a mycorrhizal association) colonizing annuals and on mycotrophic perennials were investigated in southwestern Wyoming. A subsoil containing no initial mycorrhizal inoculum was used, and seeds of the later successional perennials were planted. The annuals were removed from one‐half of the sampling quadrats to test for the interaction of competition and mycorrhizae on the perennials. During the third and fourth years of succession, the density and percent cover of Salsola kali, the most abundant nonmycotrophic annual, decreased by one‐half to one‐third with inoculation. Mycorrhizal hyphae and spores were found in the rhizosphere of S. kali, with only occasional (1–2% of the root length) penetration of hyphae into the cortex. There were no differences in tissue phosphorus and nitrogen concentrations or water relations of inoculated vs. uninoculated S. kali.The planted grasses, all Agropyron species, had no significant increase in density or percent cover with inoculation. The percent root infection of A. smithii was 5–30%. Grass density and percent cover was greatest where S. kali was present, suggesting facilitation of grass establishment by annuals on this harsh, windy site. However, grass density was lower where 5. kali density was lower following inoculation. Mycorrhizal fungi were hypothesized to hasten the rate of succession on other sites. On this site where facilitation is an important process, inoculation of early seral plants and their subsequent decline may slow primary succession in the early years.
MECHANICAL BEHAVIOR OF PLANT TISSUES AS INFERRED FROM THE THEORY OF PRESSURIZED CELLULAR SOLIDS
Authors: Niklas Karl J. 
Published: January 2018

The mechanical behavior of plant tissues and its dependency on tissue geometry and turgor pressure are analytically dealt with in terms of the theory of cellular solids. A cellular solid is any material whose matter is distributed in the form of beamlike struts or complete “cell” walls. Therefore, its relative density is less than one and typically less than 0.3. Relative density is the ratio of the density of the cellular solid to the density of its constitutive (“cell wall”) material. Relative density depends upon cell shape and the density of cell wall material. It largely influences the mechanical behavior of cellular solids. Additional important parameters to mechanical behavior are the elastic modulus of “cell walls” and the magnitude of internal “cell” pressure.Analyses indicate that two “stiffening” agents operate in natural cellular solids (plant tissues): 1) cell wall infrastructure and 2) the hydrostatic influence of the protoplasm within each cellular compartment. The elastic modulus measured from a living tissue sample is the consequence of both agents. Therefore, the mechanical properties of living tissues are dependent upon the magnitude of turgor pressure. High turgor pressure places cell walls into axial tension, reduces the magnitude of cell wall deformations under an applied stress, and hence increases the apparent elastic modulus of the tissue. In the absence of turgid protoplasts or in the case of dead tissues, the cell wall infrastructure will respond as a linear elastic, nonlinear elastic, or “densifying” material (under compression) dependent upon the magnitude of externally applied stress.Accordingly, it is proposed that no single tangent (elastic) modulus from a stress‐strain curve of a plant tissue is sufficient to characterize the material properties of a sample. It is also suggested that when a modulus is calculated that it be referred to as the tissue composite modulus to distinguish it from the elastic modulus of a noncellular solid material.