Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cyperus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed1997

Colonization pattern of aquatic hyphomycetes on leaf packs in subtropical stream.

Steralized leaf pieces of eight plants (Eucalyptus rostrata, Phoenix dactylifera, Phragmites australis, Musa nana, Salix subserrata, Cyperus alopecuroides, Ricinus communis and Eichhornia crassipes) were submerged in the Nile stream. Thirty-nine species of aquatic hyphomycetes were colonized on the plant leaves. Eucalyptus was the best substratum (30 species) for colonization by aquatic hyphomycetes. Phoenix (14 species), Phragmites (11 species), Salix (9 species), Musa (8 species), Ricinus and Cyperus (6 species) were also good substrata for aquatic hyphomycetes colonization. Echhornia (aquatic plant) was not suitable for aquatic hyphomycetes colonization. Alatospora acuminata, Triscelophorus monosporus and Tetracladium marchalianum were found to be the major colonizers on all leaf materials. Temperature and dissolved oxygen were the highest physico-chemical parameters affecting the aquatic hyphomycetes colonization. These results indicate that aquatic hyphomycetes have been shown to be successful colonizers on plants leaf in river Nile in Egypt as subtropical region.

Journal Article↗
PubMed1975

Differential cold tolerance, starch, sugar, protein, and lipid of yellow and purple nutsedge tubers.

From measurements of viability after exposure of tubers to natural overwintering in the soil and 6 weeks exposure at 2 C, species cold tolerance of the tubers was ranked in decreasing order: yellow nutsedge ;I' (Cyperus esculentus L.), an ecotype originating in Illinois; yellow nutsedge ;G', an ecotype originating in Georgia; and purple nutsedge (Cyperus rotundus L.). The ratios of unsaturated-saturated fatty acids in tuber triglycerides, tuber polar lipids, and leaf polar lipids followed the same order as the cold tolerance rankings, with the most cold-hardy species having the highest ratios. Lipid content was less than 1% of dry weight in purple nutsedge tubers, but was from 5 to 7% in both yellow nutsedge tubers. Starch, sugar, and lipid contents increased significantly in the hardy yellow nutsedge ;I' tubers during a 6-week exposure to 2 C, but did not change in the susceptible purple nutsedge tubers; only sugar increased in yellow nutsedge ;G' tubers after this treatment. Protein content was not altered by the 2 C treatment in any of the tubers. Apparently, several factors involving starch, sugar, lipids, and fatty acids are related to the differences in tolerance to cold in these species.

Journal Article↗
PubMed2001

Nitrogen removal in a combined system: vertical vegetated bed over horizontal flow sand bed.

Pig farm wastewater creates various problems in many areas throughout Thailand. Constructed wetland systems are an appropriate, low cost treatment option for tropical countries such as Thailand. In this study, a combined system (a vertical flow bed planted with Cyperus flabelliformis over a horizontal flow sand bed without plants) was used to treat settled pig farm wastewater. This system is suitable for using in farms where land is limited. The average COD and nitrogen loading rate of the vegetated vertical flow bed were 105 g/m2 x d and 11 g/m2 x d respectively. The wastewater was fed intermittently at intervals of 4 hours with a hydraulic loading rate of 3.7 cm/d. The recirculation of the effluent increased total nitrogen (TN) removal efficiency from 71% to 85%. The chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN) removal efficiencies were 95% and 98%. Nitrification was significant in vertical flow Cyperus bed, and the concentration of nitrate increased by a factor of 140. The horizontal flow sand bed enhanced COD removal and nitrate reduction was 60%. Plant uptake of nitrogen was 1.1 g N/m2 x d or dry biomass production was 2.8 kg/m2 over 100 days.

Agriculture↗
PubMed2005

[Control effects of rice-duck farming and other weed management strategies on weed communities in paddy fields].

By the methods of community ecology, field studies were conducted to evaluate the control effects of three weed management strategies, i. e., rice-duck farming (RD), manual weeding (MW) and chemical weeding (CW), on the weed communities in paddy fields. The results showed that under rice-duck farming, the weed density in paddy fields decreased significantly, and the control effects on dominant weed species such as Monochoria vaginalis, Cyperus difformis, Sagittaria pygmaea were all above 95%, with an overall effect higher than CW and MW. Under RD, the species richness and Shannon-Wiener diversity indices decreased slightly, while Pielou community evenness indices increased markedly, indicating that the species composition of weed community was greatly improved, and the infestation of former dominant weed species was reduced. The structure of weed communities in paddy fields varied with different weed management strategies, e. g., under RD, Lindernia procumbens, Cyperus difformis and Fimbristylis miliacea constituted the major weed community, and the Whittaker index was significant higher than that of CW, MW and CK, which indicated that rice-duck farming had a greater effect on the structure of the weed communities. The same conclusion could be drawn from Sorensen's similarity indices and cluster analysis with Sorensen's index as the distance measurement.

Animals↗
PubMed2006

Surveys for natural host plants of Mansonia mosquitoes inhabiting Toh Daeng peat swamp forest, Narathiwat Province, Thailand.

Surveys were carried out monthly from April-October 2002 to examine 68 sampling sites around "Toh Daeng" peat swamp forest in Narathiwat Province, Thailand, of which 38 were known Mansonia-positive habitats and 30 were Mansonia-negative sites. The present larval surveys were qualitative owing to features of the host plants (location, distribution, and abundance), difficulties in locating and selecting the host plants in the swamp forest, and time constraints. Twenty attempts were made for each species for larvae. The presence of Mansonia larvae on each plant species was confirmed 6 times for each plant and location. Larvae of Ma. bonneae and Ma. uniformis were obtained from 18 plant species (10 families): Metroxylon sagu, Melaleuca cajuputi, Pandanus militaris, Pandanus immerses, Hanguana malayana, Typha angustifolia, Hymenachne acutigluma, Scirpodendron ghaeri, Scleria sumatrensis, Rhynchospora corymnosa, Sacclolepis indica, Cyperus babakan, Cyperus corymbosus, Lepironia articulata, Leersia hexandra, Eichhornia crassipes, Pistia stratriotes and ferns. The emergent grasses, S. ghaeri, S. sumatrensis, H. acutigluma, R. corymnosa, S. indica, C. babakan, C. corymbosus, and L. articulata, were the preferred host plants. Samples from larger trees, M. sagu and M. cajuputi, yielded low numbers of 1-7 larvae per scraping. Ma. uniformis was recovered from most of the host plants, while Ma. bonneae preferred submerged plants and was not found on the floating aquatic plants, E. crassipes and P. stratriotes. The description of modified dipper and dipping techniques are given and discussed.

Animals↗
PubMed2002

DNA decay rate in papyri and human remains from Egyptian archaeological sites.

The writing sheets made with strips from the stem (caulis) of papyri (Cyperus papyrus) are one of the most ingenious products of ancient technology. We extracted DNA from samples of modern papyri varying in age from 0-100 years BP and from ancient specimens from Egypt, with an age-span from 1,300-3,200 years BP. The copy number of the plant chloroplast DNA in the sheets was determined using a competitive PCR system designed on the basis of a short (90 bp) tract of the chloroplast's ribulose bisphosphate carboxylase large subunit (rbcL) gene sequence. The results allowed us to establish that the DNA half-life in papyri is about 19-24 years. This means that the last DNA fragments will vanish within no more than 532-672 years from the sheets being manufactured. In a parallel investigation, we checked the archaeological specimens for the presence of residual DNA and determined the extent of racemization of aspartic (Asp) acid in both modern and ancient specimens, as a previous report (Poinar et al. [1996], Science 272:864-866) showed that racemization of aspartic acid and DNA decay are linked. The results confirmed the complete loss of authentic DNA, even in the less ancient (8th century AD) papyri. On the other hand, when the regression for Asp racemization rates in papyri was compared with that for human and animal remains from Egyptian archaeological sites, it proved, quite surprisingly, that the regressions are virtually identical. Our study provides an indirect argument against the reliability of claims about the recovery of authentic DNA from Egyptian mummies and bone remains.

Amino Acid Isomerases↗
PubMed2005

Confirmation of potential herbicidal agents in hulls of rice, Oryza sativa.

An ethyl acetate extract of Oryza sativa (rice) hulls yielded seven compounds: hentriacontane, 1-tetratriacontanol, beta-sitosterol, momilactone A, momilactone B, tricin (a flavonoid), and beta-sitosterol-3-O-beta-D-glucoside. The structures of these compounds were elucidated with 500 MHz nuclear magnetic resonance (NMR), using 1D and 2D spectral methods, aided by electron ionization mass spectrometry (EI-MS), fast atom bombardment mass spectrometry (FAB-MS), infrared (IR), and ultraviolet (UV) spectrophotometry. The complete 1H NMR assignments for momilactone A and B and 13C NMR assignments for tricin are discussed. To the best of our knowledge, hentriacontane, 1-tetratriacontanol, and beta-sitosterol-3-O-beta-D-glucoside were identified for the first time in rice hulls. In biological activity tests using these identified compounds, momilactone A and B showed potent inhibitory activity against duckweed (Lemna paucicostata). 1-Tetratriacontanol and beta-sitosterol-3-O-beta-D-glucoside also showed about 13-20% inhibitory activity based on chlorophyll reduction. Hentriacontane and beta-sitosterol did not show any herbicidal activity. In a germination assay of three weed species (Leptochloa chinenesis L., Amaranthus retroflexus L., and Cyperus difformis L.) in culture tubes both momilactones A and B had high inhibitory effects. Momilactone B completely inhibited germination of all three weed species at 20 ppm. Germination of L. chinensis L. was completely inhibited by a 4 ppm solution of momilactone B.

Amaranthus↗
PubMed2005

Concentrations of pesticide residues in grasses and sedges due to point source contamination and the indications for public health risks, Vikuge, Tanzania.

The concentrations of organochlorine pesticide residues were determined in roots and leaves of giant sedges (Cyperus exaltatus), fresh leaves and dry hay of guinea grasses (Panicum maximum), and in stems and leaves of elephant grasses (Pennisetum purpureum) in the vicinity of a point source of contamination, an old storage site at Vikuge farm in Tanzania. The GPC-cleaned extracts were analyzed by GC-ECD and GC/MS. The concentrations of total DDT ranged from 83 to 18274 ng/g, 166 to 7922 ng/g, and 68 to 405 ng/g, on fresh weight basis, in C. exaltatus, P. maximum and P. purpureum, respectively. The concentrations of total HCH were up to 74 ng/gfw in leaves of C. exaltatus, 43 ng/gdw in dry hay of P. maximum, and 10 ng/gfw in stems of P. purpureum. Aldrin and dieldrin were only detected in C. exaltatus and their concentrations were up to 11 and 8 ng/gfw, respectively. The strong positive correlations between the concentrations of the detected compounds suggest a common source. The concentrations of total DDT were far above the Australian extraneous maximum residue limit in primary animal feedstuffs. These findings indicate potential risks and concerns for livestock and public health. The concentrations of aldrin, dieldrin and lindane were lower than the Australian limits.

Animal Feed↗
PubMed2005

Phytoremediation in the tropics--influence of heavy crude oil on root morphological characteristics of graminoids.

When studying species for phytoremediation of petroleum-contaminated soils, one of the main traits is the root zone where enhanced petroleum degradation takes place. Root morphological characteristics of three tropical graminoids were studied. Specific root length (SRL), surface area, volume and average root diameter (ARD) of plants grown in crude oil-contaminated and uncontaminated soil were compared. Brachiaria brizantha and Cyperus aggregatus showed coarser roots in polluted soil compared to the control as expressed in an increased ARD. B. brizantha had a significantly larger specific root surface area in contaminated soil. Additionally, a shift of SRL and surface area per diameter class towards higher diameters was found. Oil contamination also caused a significantly smaller SRL and surface area in the finest diameter class of C. aggregatus. The root structure of Eleusine indica was not significantly affected by crude oil. Higher specific root surface area was related to higher degradation of petroleum hydrocarbons found in previous studies.

Biodegradation, Environmental↗
PubMed2006

Inhibitory effects of selected Thai medicinal plants on Na+,K+-ATPase.

Extracts of ten Thai indigenous medicinal plants having ethnomedical application in the treatment of dysuria were tested for their Na(+),K(+)-ATPase inhibitory activity. The hexane extracts of Cyperus rotundus and Orthosiphon aristatus showed high potent inhibitory activity on crude enzyme Na(+),K(+)-ATPase from rat brain.

Animals↗
PubMed2004

Larval damselflies in extreme environments: behavioral and physiological response to hypoxic stress.

The extensive papyrus (Cyperus papyrus) swamps of East and Central Africa form a habitat of great ecological importance due to their extent, the extreme and chronic hypoxia of the interior swamp, and the unique assemblages of water-breathing insects that characterize these communities, including zygopteran (damselfly) larvae. The major goal of this study was to quantify physiological and behavioral responses of gilled and gill-less damselfly larvae of a papyrus swamp specialist, Proischnura subfurcatum, to low-oxygen conditions. Gill autotomization was common in P. subfurcatum of the Rwembaita Swamp in Kibale National Park, Uganda, with one to three gills missing from 56% of the specimens surveyed. We examined behavioral (ventilation activity and vertical migration) and physiological (metabolic rate) response to hypoxia in gilled and gill-less P. subfurcatum. Behavioral response to progressive hypoxia indicated that gill-less individuals rely more on use of wing sheaths (lifting and spreading) than gilled P. subfurcatum larvae. However, both morphs migrated to the surface to gain contact with atmospheric air under extreme hypoxia. On average, the rate of oxygen consumption of gill-less individuals was 51% lower than that of gilled individuals. This observed metabolic depression in gill-less P. subfurcatum may be attributed to the loss of major respiratory appendages. However, the apparent ability of both gilled and gill-less individuals to maintain their metabolic rates to a similar critical tension suggests other mechanisms may compensate for loss of gills, though not enough to mediate metabolic depression.

Animals↗
PubMed2003

Effects of umbrella palms and wastewater depth on wastewater treatment in a subsurface flow constructed wetland.

On-site subsurface flow constructed wetlands are designed to provide secondary quality effluent. Plants and wetland volume are considered in their design. There have been no studies, however, comparing wastewater treatment at different wastewater depths, and plant effects in wetlands are not completely understood. Investigations were conducted on these variables using four wetland cells 228 m wide by 4.75 m long containing 1 to 5 cm diameter river rock. Cyperus alternifolius (umbrella palms) were planted in one cell, and side-by-side comparisons were made between the planted and a control cell. Side-by-side comparisons were also made between cells with equal surface areas and different depths. At best umbrella palms improved effluent 5-day biochemical oxygen demand (BOD5) by 8%, suspended solids by 6%, and did not improve fecal coliform or P wastewater quality in July. When ambient air temperatures were < or = 12 degrees C during December, plants did not improve most treatment parameters. They did, however, significantly improve NH4+ treatment even when ambient air temperatures were as low as 8 degrees C. Increasing wastewater depth enhanced fecal coliform die-off but did not reduce effluent considered when maximum NH4+ reduction is a BOD5, suspended solids, NH4+, or P in effluent. Umbrella palms should be treatment goal and it is not necessary to reduce other parameters. Surface area was more important to wastewater treatment than depth.

Cyperus↗
PubMed2006

Carbon and oxygen isotope working standards from C3 and C4 photosynthates.

A preparation of organic working standards for the online measurement of 13C/12C and 18O/16O ratios in biological material is presented. The organic working standards are simple and inexpensive C3 and C4 carbohydrates (sugars or cellulose) from distinct geographic origin, including white sugar, toilet and XEROX papers from Switzerland, maize from Ivory Coast, cane sugar from Brazil, papyrus from Egypt, and the core of the stem of a Cyperus papyrus plant from Kenya. These photosynthetic products were compared with International Atomic Energy standards CH-3 and CH-6 and other calibration materials. The presented working standards cover a 15% range of 13C/12C ratios and 9% for 18O/16O, with a precision<+/-0.2% for n>10.

Carbohydrates↗
PubMed2005

Effects of plant densities and management of purple nutsedge on sugarcane yield and effect of growth stages and main way of herbicides contact and absorption on the control of tubers.

Field experiments carried out with Cyperus rotundus L. at low (58-246), medium (318-773), and high (675-1198 shoots/m2) densities showed sugarcane yield reductions of 13.5, 29.3, and 45.2%, respectively in relation to the control. In the second field experiment, the integration of a mechanic method with two sequences of plowing and disking operations in the dry season, and complementary applications of trifloxysulfuron-sodium + ametrine and sulfentrazone (rainy season) was studied. Average of the chain connected to original shoot showed 92, 95, and 65% of reduction with trifloxysulfuron-sodium + ametrine and surfactant, at the application stages "early," preflowering, and full flowering, respectively.

Absorption↗
PubMed2003

Oscillations of plants' stems and their damping: theory and experimentation.

Free oscillations of upright plants' stems, or in technical terms slender tapered rods with one end free, can be modelled by considering the equilibrium between bending moments and moments resulting from inertia. For stems with apical loads and negligible mass of the stem and for stems with finite mass but without top loading, analytical solutions of the differential equations with appropriate boundary conditions are available for a finite number of cases. For other cases approximations leading to an upper and a lower estimate of the frequency of oscillation omega can be derived. For the limiting case of omega = 0, the differential equations are identical with Greenhill's equations for the stability against Euler buckling of slender poles. To illustrate, the oscillation frequencies of 25 spruce trees (Picea sitchensis (Bong.) Carr.) were compared with those calculated on the basis of their morphology, their density and their static elasticity modulus. For Arundo donax L. and Cyperus alternifolius L. the observed oscillation frequency was used in turn to calculate the dynamic elasticity modulus, which was compared with that determined in three-point bending. Oscillation damping was observed for A. donax and C. alternifolius for plants' stems with and without leaves or inflorescence. In C. alternifolius the difference can be attributed to the aerodynamic resistance of the leaves, whereas in A. donax structural damping in addition plays a major role.

Biomechanical Phenomena↗
PubMed2003

[Purification efficiency of vertical-flow wetland system constructed by cinder and turf substrate on municipal wastewater].

Vertical-flow constructed wetlands (VFCWs) system not only has a higher hydraulic loading rate (54-64 cm.d-1), but also has a good removal efficiency for organics, ammonia nitrogen (AN) and total phosphorus (TP). The removal efficiencies of COD, BOD5, AN, and TP for septic tank effluent were 76-87%, 82-92%, 75-85% and 77-91%, respectively, and the average effluent concentrations of COD, BOD5, AN, and TP in the treated effluent were less than 60, 20, 25 and 2.0 mg.L-1, respectively. A comparison of planted and unplanted columns showed that plantation of Cyperus alternifolius could increase the removal rates of AN, TN, and TP by 2-3%, 4-6%, and 10-14%, respectively.

Ammonia↗
PubMed2003

Biotypes resistant to herbicides in paddy fields in the Iberian Peninsula.

A consequence of modern agriculture and its dependence on herbicides, is the appearance of resistant weed populations. The first case of resistance on the Iberian Peninsula was found in Portugal and it was in a population of Alisma plantago-aquatica, resistant to bensulfuronmethyl, an ALS-inhibitor. For the same herbicide, control problems with Cyperus difformis were found in some Spanish rice fields. In the same rice field area, tolerance was observed in some Echinochloa spp. when auxinic herbicides (quinclorac) were used and some resistant Echinochloa spp. populations were found due to the long use of PS II inhibitors herbicides (propanil). The association of active ingredients, rotation of crops and adoption of mechanical control methods are the main strategies to combat resistance to herbicides.

Acetolactate Synthase↗
PubMed2006

Status of Eldana saccharina (Lepidoptera: Pyralidae), its host plants and natural enemies in Ethiopia.

Surveys for sugarcane stem borers were undertaken in Ethiopia to determine the prevalence and distribution of these and their natural enemies in crops and indigenous host plants. Eldana saccharina Walker was not recovered from sugarcane, but was present in three indigenous wetland sedges, Cyperus papyrus, C. fastigiatus and C. dives in the southern, central and northern part of the country. The latter indigenous host plant was present in waterways adjacent to sugarcane on the commercial sugar estates. The tachinids Schembria eldanae Barraclough and Actia sp. were common parasitoids of E. saccharina larvae in these indigenous sedges. The braconid Dolichogenidea sp. was recovered from E. saccharina larvae in C. dives. Pathogens comprising Beauveria bassiana, Bacillus thuringiensis and Entomophthora sp., were found to be important mortality factors of E. saccharina larvae in the indigenous sedges. The occurrence of E. saccharina in Ethiopia is reported for the first time, and the host plant preferences of the borer and its indigenous natural enemies found during the surveys are recorded. In addition, its potential threat to sugarcane production in Ethiopia is discussed.

Animals↗