Transport of Water and Solutes in Plants

Journal of Water and Environment Technology, Vol. 9, No.2, 2011 Address correspondence to Naohiro Kishida, Water Management Sector, Department of Environmental Health, National Institute of Public Health, Email: kishida@niph.go.jp Received December 9, 2010, Accepted March 3, 2011. - 225 - Annual and Diurnal Profiles of Cryptosporidium and Giardia in River Water in Japan Naohiro KISHIDA*, Masayuki NAKANO*, Kyungju KIM*, Eiji HARAMOTO**, Shigemitsu MORITA***, Mari ASAMI*, Michihiro AKIBA* *Division of Water Management, Department of Environmental Health, National Institute of Public Health, 2-3-6 Minami, Wako, Saitama 351-0197, Japan **Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan ***School of Environmental Science, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan ABSTRACT A quantitative survey was performed to understand the annual and diurnal profiles of Cryptosporidium and Giardia, representative waterborne infectious protozoans, in river water which is used for drinking water sources in Japan. To investigate the annual profiles, 84 river water samples were collected at 7 sites in the tributary rivers of the Tone River basin in Japan from June 2008 to February 2010. Cryptosporidium and Giardia were detected in 59 (70%) and 64 (76%) out of the 84 samples (10 liters each), showing the highest concentration of 344 oocysts/10 L and 144 cysts/10 L, respectively. Annual variation of the concentrations of Cryptosporidium and Giardia was high. The ratio of the maximum concentration to the mean value at each sampling site ranged from 2–8 except for one sampling site in which the frequency of detection was extremely low. To investigate diurnal profiles, 15 river water samples were collected at 3 sites in the tributary rivers of the Tone River on October 9 th , 2008. The maximum concentrations of Cryptosporidium and Giardia in some sampling sites were approximately 10-fold higher than the lowest value. The correlation between the anaerobic spore-forming bacteria and these infectious protozoans was stronger than other microbial indicators (total coliforms, Escherichia coli and heterotrophic bacteria). Keywords: cryptosporidiosis, Cryptosporidium, drinking water, Giardia, giardiasis. INTRODUCTION Cryptosporidium and Giardia are enteric protozoans that cause diarrheal disease and significant adverse health effects in humans (Fayer, 2004; Craun et al., 2005; Sunderland et al., 2007). These parasites are widely distributed throughout the world and transmitted through contaminated water and food. Waterborne cryptosporidiosis and giardiasis are particularly important because their transmissive stages, i.e., oocysts and cysts, respectively, are resistant to disinfectants (such as chlorine) commonly used for water treatment (Peeters et al., 1989; Carpenter et al., 1999). The most notorious waterborne outbreak occurred in Milwaukee, Wisconsin, in 1993 where more than 400,000 suspected and 5,000 confirmed cases of clinical cryptosporidiosis were reported (MacKenzie et al., 1995; Cicirello et al., 1997; Corso et al., 2003). In Japan, an outbreak occurred in Ogose Town, Saitama Prefecture, in 1996 where more than 8,800 suspected cases were reported, accounting for Transport of Water and Solutes in Plants Transport of Water and Solutes in Plants Bởi: OpenStaxCollege The structure of plant roots, stems, and leaves facilitates the transport of water, nutrients, and photosynthates throughout the plant The phloem and xylem are the main tissues responsible for this movement Water potential, evapotranspiration, and stomatal regulation influence how water and nutrients are transported in plants To understand how these processes work, we must first understand the energetics of water potential Water Potential Plants are phenomenal hydraulic engineers Using only the basic laws of physics and the simple manipulation of potential energy, plants can move water to the top of a 116-meter-tall tree ([link]a) Plants can also use hydraulics to generate enough force to split rocks and buckle sidewalks ([link]b) Plants achieve this because of water potential With heights nearing 116 meters, (a) coastal redwoods (Sequoia sempervirens) are the tallest trees in the world Plant roots can easily generate enough force to (b) buckle and break concrete sidewalks, much to the dismay of homeowners and city maintenance departments (credit a: modification of work by Bernt Rostad; credit b: modification of work by Pedestrians Educating Drivers on Safety, Inc.) 1/12 Transport of Water and Solutes in Plants Water potential is a measure of the potential energy in water Plant physiologists are not interested in the energy in any one particular aqueous system, but are very interested in water movement between two systems In practical terms, therefore, water potential is the difference in potential energy between a given water sample and pure water (at atmospheric pressure and ambient temperature) Water potential is denoted by the Greek letter ψ (psi) and is expressed in units of pressure (pressure is a form of energy) called megapascals (MPa) The potential of pure water (Ψwpure H2O) is, by convenience of definition, designated a value of zero (even though pure water contains plenty of potential energy, that energy is ignored) Water potential values for the water in a plant root, stem, or leaf are therefore expressed relative to Ψwpure H2O The water potential in plant solutions is influenced by solute concentration, pressure, gravity, and factors called matrix effects Water potential can be broken down into its individual components using the following equation: Ψsystem = Ψtotal = Ψs + Ψp + Ψg + Ψm where Ψs, Ψp, Ψg, and Ψm refer to the solute, pressure, gravity, and matric potentials, respectively “System” can refer to the water potential of the soil water (Ψsoil), root water (Ψroot), stem water (Ψstem), leaf water (Ψleaf) or the water in the atmosphere (Ψatmosphere): whichever aqueous system is under consideration As the individual components change, they raise or lower the total water potential of a system When this happens, water moves to equilibrate, moving from the system or compartment with a higher water potential to the system or compartment with a lower water potential This brings the difference in water potential between the two systems (ΔΨ) back to zero (ΔΨ = 0) Therefore, for water to move through the plant from the soil to the air (a process called transpiration), Ψsoil must be > Ψroot > Ψstem > Ψleaf > Ψatmosphere Water only moves in response to ΔΨ, not in response to the individual components However, because the individual components influence the total Ψsystem, by manipulating the individual components (especially Ψs), a plant can control water movement Solute Potential Solute potential (Ψs), also called osmotic potential, is negative in a plant cell and zero in distilled water Typical values for cell cytoplasm are –0.5 to –1.0 MPa Solutes reduce water potential (resulting in a negative Ψw) by consuming some of the potential energy available in the water Solute molecules can dissolve in water because water molecules can bind to them via hydrogen bonds; a hydrophobic molecule like oil, which cannot bind to water, cannot go into solution The energy in the hydrogen bonds between solute molecules and water is no longer available to work in the system because it is tied 2/12 Transport of Water and Solutes in Plants up in the bond In other words, the amount of available potential energy is reduced when solutes are added to an aqueous system Thus, Ψs decreases with increasing solute concentration Because Ψs is one of the four components of Ψsystem or Ψtotal, a decrease in Ψs will cause a decrease in Ψtotal The internal water potential of a plant cell is more negative than pure water because of the cytoplasm’s high solute content ([link]) Because of this difference in water potential water will move from the soil into a plant’s root cells via the process of osmosis This is why solute potential is sometimes called osmotic potential Plant cells can metabolically manipulate Ψs (and by extension, Ψtotal) by adding or removing solute molecules Therefore, plants have control over Ψtotal via their ...Oligomerization of the Mg 2+ -transport proteins Alr1p and Alr2p in yeast plasma membrane Marcin Wachek 1 , Michael C. Aichinger 1 , Jochen A. Stadler 2 , Rudolf J. Schweyen 1 and Anton Graschopf 1 1 Max F. Perutz Laboratories, Department of Genetics, University of Vienna, Austria 2 EMBL, Heidelberg, Germany Mg 2+ is the most abundant bivalent cation. It is involved in many cellular functions (as cofactor in numerous enzymatic reactions), particularly mediating phosphotransfer, and has extensive influence on macromolecular structures of nucleic acids, proteins and membranes. It also plays important roles in con- trolling the activities of the Ca 2+ and K + channels in the plasma membrane. Mg 2+ uptake into cells and from cytoplasm into mitochondria and chloroplasts is mediated by specific transport proteins and is driven by the inside negative membrane potential. The CorA protein is the major Mg 2+ -transport protein in bacteria and archaea [1,2]. A distantly related protein, named Mrs2, has been shown to mediate Mg 2+ uptake into yeast mitochon- dria [3]. Orthologs of this protein also exist in mito- chondria of mammals and plants as well as in plant chloroplasts and plasma membranes [4–6]. The yeast Saccharomyces cerevisiae makes use of another class of distant orthologs of CorA, named Alr1 and Alr2, for Mg 2+ influx through the plasma membrane, and most members of ascomycota appear to encode proteins of the this subfamily of CorA-related proteins. In the absence of Alr1p, yeast cells undergo growth arrest in standard media when intracellular Mg 2+ concentra- tions fall to  50% of those in wild-type cells. Growth arrest can be suppressed by an increase in Mg 2+ con- centrations of growth medium above 20 mm or by overexpression of Alr2p [7,8]. The only Mg 2+ -trans- port proteins that do not belong to the CorA Keywords magnesium; oligomerization; plasma membrane; split-ubiquitin; transport Correspondence A. Graschopf, Department of Genetics, University of Vienna, A-1030 Vienna, Dr Bohr-Gasse, Austria Fax: +43 1 4277 9546 Tel: +43 1 4277 54614 E-mail: anton.graschopf@univie.ac.at (Received 5 May 2006, revised 6 July 2006, accepted 17 July 2006) doi:10.1111/j.1742-4658.2006.05424.x Alr1p is an integral plasma membrane protein essential for uptake of Mg 2+ into yeast cells. Homologs of Alr1p are restricted to fungi and some protozoa. Alr1-type proteins are distant relatives of the mitochondrial and bacterial Mg 2+ -transport proteins, Mrs2p and CorA, respectively, with which they have two adjacent TM domains and a short Mg 2+ signature motif in common. The yeast genome encodes a close homolog of Alr1p, named Alr2p. Both proteins are shown here to be present in the plasma membrane. Alr2p contributes poorly to Mg 2+ uptake. Substitution of a single arginine with a glutamic acid residue in the loop connecting the two TM domains at the cell surface greatly improves its function. Both proteins are shown to form homo-oligomers as well as hetero-oligomers. Wild-type Alr2p and mutant Alr1 proteins can have dominant-negative effects on wild-type Alr1p activity, presumably through oligomerization of low-func- tion with full-function proteins. Chemical cross-linking indicates the pres- ence of Alr1 oligomers, and split-ubiquitin assays reveal Alr1p–Alr1p, Alr2p–Alr2p, and Alr1p–Alr2p interactions. These MPIfG Discussion Paper 11/14 Making the Poor Pay for Public Goods via Microfinance Economic and Political Pitfalls in the Case of Water and Sanitation Philip Mader Philip Mader Making the Poor Pay for Public Goods via Microfinance: Economic and Political Pitfalls in the Case of Water and Sanitation MPIfG Discussion Paper 11/14 Max-Planck-Institut für Gesellschaftsforschung, Köln Max Planck Institute for the Study of Societies, Cologne September 2011 MPIfG Discussion Paper ISSN 0944-2073 (Print) ISSN 1864-4325 (Internet) © 2011 by the author(s) Philip Mader is a researcher at the Max Planck Institute for the Study of Societies. mader@mpifg.de MPIfG Discussion Papers are refereed scholarly papers of the kind that are publishable in a peer-reviewed disciplinary journal. Their objective is to contribute to the cumulative improvement of theoretical knowl- edge. The papers can be ordered from the institute for a small fee (hard copies) or downloaded free of charge (PDF). Downloads www.mpifg.de Go to Publications / Discussion Papers Max-Planck-Institut für Gesellschaftsforschung Max Planck Institute for the Study of Societies Paulstr. 3 | 50676 Cologne | Germany Tel. +49 221 2767-0 Fax +49 221 2767-555 www.mpifg.de info@mpifg.de Mader: Making the Poor Pay for Public Goods via Microfinance iii Abstract This paper critically assesses microfinance’s expansion into the provision of public goods. It focuses on the problem of public goods and collective action and refers to the specific example of water and sanitation. The microfinancing of water and sanitation is a private business model which requires households to recognise, internalise and capitalise the benefits from improved water and sanitation. This requirement is not assured. Water and sanitation, being closely linked to underlying common-pool resources, are public goods which depend on collective governance solutions. They also have shifting public/private characteristics and are merit goods which depend on networks to enable provision to take place. Two cases, from Vietnam and India, are presented and evaluated. Despite their dissimilar settings and institutional designs, evidence is found that both projects encountered similar and comparable problems at the collective level which individual microfinance loans could not address. The paper concludes that trying to make the poor pay for public goods runs into four pitfalls: politics, public capacity, values and equity. Zusammenfassung Das Papier untersucht die Auswirkungen von Mikrofinanzierung auf öffentliche Güter und kollektives Handeln am Beispiel der Errichtung von Wasser- und Sanitäranlagen in Ländern der Dritten Welt. Das zugrunde liegende private Geschäftsmodell geht davon aus, dass Haushalte mittels Mikrokredite die Vorteile verbesserter Wasser- und Sani- täreinrichtungen erkennen und sich auch finanziell zunutze machen können – diese Voraussetzung ist allerdings nicht gegeben. Zudem sind Wasser- und Sanitärversorgung meritorische Güter, für deren Bereitstellung Netzwerke erforderlich sind. Sie erfordern eine kollektive Verwaltung, weil sie sowohl öffentliche als auch private Merkmale auf- weisen und mit Gemeinschaftsgütern eng verknüpft sind. Ausgangslage und institu- tionelle Rahmenbedingungen Simulation of Ground-Water Flow and Evaluation of Water-Management Alternatives in the Assabet River Basin, Eastern Massachusetts By Leslie A. DeSimone In cooperation with the Massachusetts Department of Conservation and Recreation Scientific Investigations Report 2004-5114 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior Gale A. Norton, Secretary U.S. Geological Survey Charles G. Groat, Director U.S. Geological Survey, Reston, Virginia: 2004 For sale by U.S. Geological Survey, Information Services Box 25286, Denver Federal Center Denver, CO 80225 For more information about the USGS and its products: Telephone: 1-888-ASK-USGS World Wide Web: http://www.usgs.gov/ Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: DeSimone, L.A., 2004, Simulation of ground-water flow and evaluation of water-management alternatives in the Assabet River Basin, eastern Massachusetts: U.S. Geological Survey Scientific Investigations Report 2004-5114, 133 p. iii Contents Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Description of the Study Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Previous Studies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Ground- and Surface-Water Resources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Geologic Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Hydraulic Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Ground-Water Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Recharge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Water Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Surface Water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Streamflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Ponds and Wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Water Use and Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... the water levels are equal 11/12 Transport of Water and Solutes in Plants [link] Which of the following statements is false? Negative water potential draws water into the root hairs Cohesion and. .. the system The force of gravity pulls water downwards to the soil, reducing the total amount of potential energy in the water 4/12 Transport of Water and Solutes in Plants in the plant (Ψtotal)... walls of the xylem vessels and tracheids, and the cohesion of water molecules to each other This is called the cohesion–tension theory of sap ascent 5/12 Transport of Water and Solutes in Plants Inside