Interactions between magnesium, calcium, and aluminum on soybean root elongation

Alleviation of Al rhizotoxicity by Ca and Mg can differ among species and genotypes. Root elongation of soybean [Glycine max (L.) Merr.] line N93-S-179 and cvs. Young and Ransom exposed to varying concentrations of Al, Ca and Mg were compared in two experiments using a vertically split root system. Roots extending from a surface compartment with limed soil grew for 12 days into a subsurface compartment with nutrient solution treatments maintained at pH 4.6 with either 0 or 15 µmol L-1 Al. Calcium and Mg concentrations in treatments ranging from 0 to 20 mmol L-1. Although an adequate supply of Mg was provided in the surface soil compartment for soybean top growth, an inclusion of Mg was necessary in the subsurface solutions to promote root elongation in both the presence and absence of Al. In the absence of Al in the subsurface solution, tap root length increased by 74 % and lateral root length tripled when Mg in the solutions was increased from 0 to either 2 or 10 mmol L-1. In the presence of 15 µmol L-1 Al, additions of 2 or 10 mmol L-1 Mg increased tap root length fourfold and lateral root length by a factor of 65. This high efficacy of Mg may have masked differences in Al tolerance between genotypes N93 and Young. Magnesium was more effective than Ca in alleviating Al rhizotoxicity, and its ameliorative properties could not be accounted for by estimated electrostatic changes in root membrane potential and Al3+ activity at the root surface. The physiological mechanisms of Mg alleviation of Al injury in roots, however, are not known.

Study Regarding Implementation of a Uniform Statewide System to Allow for Electronic Transactions for the Registration and Titling of Motor Vehicles

LEGISLATIVE STUDY – The 83rd General Assembly of the Iowa Legislature, in Senate File 2273, directed the Iowa Department of Transportation (DOT) to conduct a study of how to implement a uniform statewide system to allow for electronic transactions for the registration and titling of motor vehicles. PARTICIPANTS IN STUDY – As directed by Senate File 2273, the DOT formed a working group to conduct the study that included representatives from the Consumer Protection Division of the Office of the Attorney General, the Department of Public Safety, the Department of Revenue, the Iowa State County Treasurer’s Association, the Iowa Automobile Dealers Association, and the Iowa Independent Automobile Dealers Association. CONDUCT OF THE STUDY – The working group met eight times between June 17, 2010, and October 1, 2010. The group discussed the costs and benefits of electronic titling from the perspectives of new and used motor vehicle dealers, county treasurers, the DOT, lending institutions, consumers and consumer protection, and law enforcement. Security concerns, legislative implications, and implementation timelines were also considered. In the course of the meetings the group: 1. Reviewed the specific goals of S.F. 2273, and viewed a demonstration of Iowa’s current vehicle registration and titling system so participants that were not users of the system could gain an understanding of its current functionality and capabilities. 2. Reviewed the results of a survey of county treasurers conducted by the DOT to determine the extent to which county treasurers had processing backlogs and the extent to which county treasurers limited the number of dealer registration and titling transactions that they would process in a single day and while the dealer waited. Only eight reported placing a limit on the number of dealer transactions that would be processed while the dealer waited (with the number ranging from one to four), and only 11 reported a backlog in processing registration and titling transactions as of June 11, 2010, with most backlogs being reported in the range of one to three days. 3. Conducted conference calls with representatives of the American Association of Motor Vehicle Administrators (AAMVA) and representatives of three states -- Kansas, which has an electronic lien and titling (ELT) program, and Wisconsin and Florida, each of which have both an ELT program and an electronic registration and titling (ERT) program – to assess current and best practices for electronic transactions. In addition, the DOT (through AAMVA) submitted a survey to all U.S. jurisdictions to determine how, if at all, other states implemented electronic transactions for the registration and titling of motor vehicles. Twenty-eight states responded to the survey; of the 28 states that responded, only 13 allowed liens to be added or released electronically, and only five indicated allowing applications for registration and titling to be submitted electronically. DOT staff also heard a presentation from South Dakota on its ERT system at an AAMVA regional meeting. ELT information that emerged suggests a multi-vendor approach, in which vendors that meet state specifications for participation are authorized to interface with the state’s system to serve as a portal between lenders and the state system, will facilitate electronic lien releases and additions by offering lenders more choices and the opportunity to use the same vendor in multiple states. The ERT information that emerged indicates a multi-interface approach that offers an interface with existing dealer management software (DMS) systems and through a separate internet site will facilitate ERT by offering access that meets a variety of business needs and models. In both instances, information that emerged indicates that, in the long-term, adoption rates are positively affected by making participation above a certain minimum threshold mandatory. 4. To assess and compare functions or services that might be offered by or through a vendor, the group heard presentations from vendors that offer products or services that facilitate some aspect of ELT or ERT. 5. To assess the concerns, needs and interest of Iowa motor vehicle dealers, the group surveyed dealers to assess registration and titling difficulties experienced by dealers, the types of DMS systems (if any) used by dealers, and the dealers’ interest and preference in using an electronic interface to submit applications for registration and titling. Overall, 40% of the dealers that responded indicated interest and 57% indicated no interest, but interest was pronounced among new car dealers (75% were interested) and dealers with a high number of monthly transactions (85% of dealers averaging more than 50 sales per month were interested). The majority of dealers responding to the dealer survey ranked delays in processing and problems with daily limits on transaction as ―minor difficulty or ―no difficulty. RECOMMENDATIONS -- At the conclusion of the meetings, the working group discussed possible approaches for implementation of electronic transactions in Iowa and reached a consensus that a phased implementation of electronic titling that addressed first electronic lien and title transactions (ELT) and electronic fund transfers (EFT), and then electronic applications for registration and titling (ERT) is recommended. The recommendation of a phased implementation is based upon recognition that aspects of ELT and EFT are foundational to ERT, and that ELT and EFT solutions are more readily and easily attained than the ERT solution, which will take longer and be somewhat more difficult to develop and will require federal approval of an electronic odometer statement to fully implement. ELT – A multi-vendor approach is proposed for ELT. No direct costs to the state, counties, consumers, or dealers are anticipated under this approach. The vendor charges participating lenders user or transaction fees for the service, and it appears the lenders typically absorb those costs due to the savings offered by ELT. Existing staff can complete the programming necessary to interface the state system with vendors’ systems. The estimated time to implement ELT is six to nine months. Mandatory participation is not recommended initially, but should be considered after ELT has been implemented and a suitable number of vendors have enrolled to provide a fair assessment of participation rates and opportunities. EFT – A previous attempt to implement ELT and EFT was terminated due to concern that it would negatively impact county revenues by reducing interest income earned on state funds collected by the county and held until the monthly transfer to the state. To avoid that problem in this implementation, the EFT solution should remain revenue neutral to the counties, by allowing fees submitted by EFT to be immediately directed to the proper county account. Because ARTS was designed and has the capacity to accommodate EFT, a vendor is not needed to implement EFT. The estimated time to implement EFT is six to nine months. It is expected that EFT development will overlap ELT development. ERT – ERT itself must be developed in phases. It will not be possible to quickly implement a fully functioning, paperless ERT system, because federal law requires that transfer of title be accompanied by a written odometer statement unless approval for an alternate electronic statement is granted by the National Highway Traffic Safety Administration (NHTSA). It is expected that it will take as much as a year or more to obtain NHTSA approval, and that NHTSA approval will require design of a system that requires the seller to electronically confirm the seller’s identity, make the required disclosure to the buyer, and then transfer the disclosure to the buyer, who must also electronically confirm the buyer’s identity and electronically review and accept the disclosure to complete and submit the transaction. Given the time that it will take to develop and gain approval for this solution, initial ERT implementation will focus on completing and submitting applications and issuing registration applied for cards electronically, with the understanding that this process will still require submission of paper documents until an electronic odometer solution is developed. Because continued submission of paper documents undermines the efficiencies sought, ―full‖ ERT – that is, all documents necessary for registration and titling should be capable of approval and/or acceptance by all parties, and should be capable of submission without transmittal or delivery of duplicate paper documents .– should remain the ultimate goal. ERT is not recommended as a means to eliminate review and approval of registration and titling transactions by the county treasurers, or to place registration and titling approval in the hands of the dealers, as county treasurers perform an important role in deterring fraud and promoting accuracy by determining the genuineness and regularity of each application. Authorizing dealers to act as registration agents that approve registration and title applications, issue registration receipts, and maintain and deliver permanent metal license plates is not recommended. Although distribution of permanent plates by dealers is not recommended, it is recommended that dealers participating in ERT generate and print registration applied for cards electronically. Unlike the manually-issued cards currently in use, cards issued in this fashion may be queried by law enforcement and are less susceptible to misuse by customers and dealers. The estimated time to implement the electronic application and registration applied for cards is 12 to 18 months, to begin after ELT and EFT have been implemented. It is recommended that focus during this time be on facilitating transfers through motor vehicle dealers, with initial deployment focused on higher-volume dealers that use DMS systems. In the long term an internet option for access to ERT must also be developed and maintained to allow participation for lower-volume dealers that do not use a DMS system. This option will also lay the ground work for an ERT option for sales between private individuals. Mandatory participation in Iowa is not recommended initially. As with ELT, it is recommended that mandatory participation be considered after at least an initial phase of ERT has been implemented and a suitable number of dealers have enrolled to provide a fair assessment of participation rates and opportunities. The use of vendors to facilitate ERT is not initially proposed because 1) DOT IT support staff is capable of developing a system that will interact with DMS systems and will still have to develop a dealer and public interface regardless of whether a vendor acts as intermediary between the DMS systems, and 2) there is concern that the cost of the vendor-based system, which is funded by transaction-based payments from the dealer to the vendor, will be passed to the consumer in the form of additional documentation or conveyance fees. However, the DOT recommends flexibility on this point, as development and pilot of the system may indicate that a multi-vendor approach similar to that recommended for ELT may increase the adoption rate by larger dealers and may ultimately decrease the user management to be exercised by DOT staff. If vendors are used in the process, additional legislation or administrative rules may be needed to control the fees that may be passed to the consumer. No direct cost to the DOT or county treasurers is expected, as the DOT expects that it may complete necessary programming with existing staff. Use of vendors to facilitate ERT transactions by dealers using DMS systems would result in transaction fees that may ultimately be passed to consumers. LEGISLATION – As a result of the changes implemented in 2004 under Senate File 2070, the only changes to Iowa statutes proposed are to section 321.69 of the Iowa Code, ―Damage disclosure statement,and section 321.71, ―Odometer requirements.‖ In each instance, authority to execute these statements by electronic means would be clarified by authorizing language similar to that used in section 321.20, subsections ―2‖ and ―3,‖ which allows for electronic applications and directs the department to ―adopt rules on the method for providing signatures for applications made by electronic means.‖ In these sections, the authorizing language might read as follows: Notwithstanding contrary provisions of this section, the department may develop and implement a program to allow for any statement required by this section to be made electronically. The department shall adopt rules on the method for providing signatures for statements made by electronic means. Some changes to DOT administrative rules will be useful but only to enable changes to work processes that would be desirable in the long term. Examples of long term work processes that would be enabled by rule changes include allowing for signatures created through electronic means and electronic odometer certifications. The DOT rules, as currently written, do not hinder the ability to proceed with ELT, EFT, and ERT.

Les traitements de l'ostéoporose (à l'exception de la substitution hormonale et de ses dérivés) [Treatment of osteoporosis (with the exception of hormone replacement and its derivates]

Calcium and vitamin D supplementation are warranted for the treatment of osteoporosis, when other specific drugs are used. Vitamin D supplementation is necessary when the plasma level of 25-hydroxy-vitamin D is below 30 nmol/l (12 pg/l) in order to avoid any increase of the plasma parathyroid hormone level. Bisphosphonates are the most widely drugs used. Recent advances will provide patients with a more convenient therapeutically equivalent alternative: the once-weekly oral dosing regimen and probably the possibility to give infusions at intervals of up to one year. Parathyroid hormone administered subcutaneously daily produced a dramatic increase of trabecular and cortical bone mineral density, and an important decrease of vertebral and nonvertebral fracture risk. Strontium is a new original drug, which stimulates bone formation, and inhibits bone resorption. It significantly improves trabecular and cortical bone mass. Calcitonin not only prevents the recurrence of vertebral fractures, but possibly could decrease hip fractures risk. Hydrochlorothiazide preserves the bone mineral density, and decreases nonvertebral fracture risk, as showed in epidemiological studies. Large clinical trials with statins therapy in appropriate populations are required to find out whether these drugs have any role in preventing fractures.

Reforming the Iowa Civil Justice System, January 30, 2012

Executive Summary I. Survey The Task Force conducted a wide-ranging survey of more than 9,000 licensed Iowa attorneys and judges to obtain their input on a variety of civil justice system topics. The survey results helped inform the Task Force of problem areas in Iowa’s civil justice system. II. Two-Tier Justice System The Task Force recommends a pilot program based on a two-tier civil justice system. A two-tier system would streamline litigation processes—including rules of evidence and discovery disclosures—and reduce litigation costs of certain cases falling below a threshold dollar value. III. One Judge/One Case and Date Certain for Trial Some jurisdictions in Iowa have adopted one judge/one case and date certain for trial in certain cases. The assignment of one judge to each case for the life of the matter and the establishment of dates certain for civil trials could enhance Iowans’ access to the courts, improve judicial management, promote consistency and adherence to deadlines, and reduce discovery excesses. IV. Discovery Processes Reforms addressing inefficient discovery processes will reduce delays in and costs of litigation. Such measures include adopting an aspirational purpose for discovery rules to “secure the just, speedy, and inexpensive determination of every action,” holding discovery proportional to the size and nature of the case, requiring initial disclosures, limiting the number of expert witnesses, and enforcing existing rules. V. Expert Witness Fees The Task Force acknowledges the probable need to revisit the statutory additional daily compensation limit for expert witness fees. Leaving the compensation level to the discretion of the trial court is one potential solution. VI. Jurors Additions to the standard juror questionnaire would provide a better understanding of the potential jurors’ backgrounds and suitability for jury service. The Task Force encourages adoption of more modern juror educational materials and video. Rehabilitation of prospective jurors who express an unwillingness or inability to be fair should include a presumption of dismissal. VII. Video and Teleconferencing Options When court resources are constrained both by limited numbers of personnel and budget cuts, it is logical to look to video and teleconferencing technology to streamline the court process and reduce costs. The judicial branch should embrace technological developments in ways that will not compromise the fairness, dignity, solemnity, and decorum of judicial proceedings. VIII. Court-Annexed Alternative Dispute Resolution(ADR) Litigants and practitioners in Iowa are generally satisfied with the current use of private, voluntary ADR for civil cases. There is concern, however, that maintaining the status quo may have steep future costs. Court-annexed ADR is an important aspect of any justice system reform effort, and the Task Force perceives benefits and detriments to reforming this aspect of the Iowa civil justice system. IX. Relaxed Requirement of Findings of Fact and Conclusions of Law A rule authorizing parties to waive findings of fact and conclusions of law could expedite resolution of nonjury civil cases. X. Business (Specialty) Courts Specialty business courts have achieved widespread support across the country. In addition, specialty courts provide excellent vehicles for implementing or piloting other court innovations that may be useful in a broader court system context. A business specialty court should be and could be piloted in Iowa within the existing court system framework of the Iowa Judicial Branch. Appendix included as a separate document, is 176 pages.

Retention half times in the skeleton of plutonium and Sr-90 from above-ground nuclear tests: A retrospective study of the Swiss population

Plutonium and Sr-90 are considered to be among the most radiotoxic nuclides produced by the nuclear fission process. In spite of numerous studies on mammals and humans there is still no general agreement on the retention half time of both radionuclides in the skeleton in the general population. Here we determined plutonium and Sr-90 in human vertebrae in individuals deceased between 1960 and 2004 in Switzerland. Plutonium was measured by sensitive SF-ICP-MS techniques and Sr-90 by radiometric methods. We compared our results to the ones obtained for other environmental compartments to reveal the retention half time of NBT fallout Pu-239 and Sr-90 in trabecular bones of the Swiss population. Results show that plutonium has a retention half time of 40 +/- 14 years. In contrast Sr-90 has a shorter retention half time of 13.5 +/- 1.0 years. Moreover Sr-90 retention half time in vertebrae is shown to be linked to the retention half time in food and other environmental compartments. These findings demonstrate that the renewal of the vertebrae through calcium homeostatic control is faster for Sr-90 excretion than for plutonium excretion. The precise determination of the retention half time of plutonium in the skeleton will improve the biokinetic model of plutonium metabolism in humans. (C) 2010 Elsevier Ltd. All rights reserved.

Circum-Alpine marine circulation and paleoenvironmental conditions during the Miocene

Trace element and isotopic compositions of marine fossils and sediment were analyzed from several Miocene deposits in the circum-Alpine region in order to reconstruct the paleoceanographic and paleoclimatic changes related to sea level changes, basin evolution and Alpine orogeny. To the north and the east the Alps were border by an epicontinental sea, the Paratethys, while to the south the Mediterranean surrounded the uplifting mountains during the Miocene. The thesis mainly focused on sediments and fossils sampled from Miocene beds of these two oceanic provinces. The north Alpine Molasse, the Vienna and Pannonian Basins were located in the Western and Central Paratethys. O-isotope compositions of well-preserved phosphatic fossils in these sediments support deposition under sub-tropical to warm-temperate climate with water temperatures between 14 to 28 °C for the Miocene. δ18O values of fossil shark teeth from different horizons vary similarly to those of the global trend until the end of the Badenian, however the δ18O values show wider range, which indicates local effects iii the sub-basins. The trend of 87Sr/86Sr in the samples roughly agrees with an open ocean environment for the Miocene. Yet a number of samples deviate from typical open ocean compositions with higher ratios suggesting modification of seawater by local and old terrestrial sources. In contrast, two exceptional teeth from the locality of La Moliere have extremely low δ18O values and low 87Sr/86Sr. However, the REE patterns of their enameloid are similar to those of teeth having O and Sr isotopic compositions typical of a marine setting at this site. Collectively, this suggests that the two teeth formed while the sharks frequented a freshwater environment with very low 18O-content and 87Sr/86Sr controlled by Mesozoic calcareous rocks. This is consistent with a paleogeography of high-elevation (~2300m) Miocene Alps adjacent to a marginal sea. The local effects are also reflected in the εNd values of the Paratethyan fossils, which is compatible with input from ancient crystalline rocks and Mesozoic sediments, while other samples with elevated εNd values indicate an influence of Neogene volcanism on the water budget. Excluding samples whose isotopic compositions reflect a local influence on the water column, an average εNd value of -7.9 ± 0.5 may be inferred for the Paratethys seawater. This value is indistinguishable from the Miocene value of the Indian Ocean, supporting a dominant role of ludo-Pacific water masses in the Paratethys. Regarding the Mediterranean, stable C-and O-isotope compositions of benthic and planktonic foraminifera from the Umbria-Marche region (UMC) have an offset typical for their habitats and the changes in composition mimic global changes, suggesting that the regional conditions of climate and the carbon cycle were controlled by global changes. The radiogenic isotope compositions of the fossil assemblages allow for distinction of periods. From 25 to 19 Ma, high εNd values and low 87Sr/86Sr of sediments and fossils support intense tectonism and volcanism, related to the opening of the western Mediterranean. Between 19 and 13 Ma the Mediterranean has εNd values that are largely controlled by incursion of Indian Ocean water. Brief periods of local hinterland control on seawater compositions are indicated by spikes in the εNd record, coinciding with volcanic events and a short sea-level decrease at about 15.2 Ma. Lower 87Sr/86Sr compared to the open ocean is compatible with rapid uplift of the hinterland and intense influx of Sr from Mesozoic carbonates of the western Apennines, while higher 87Sr/86Sr for other sites indicates erosion of old crustal silicate rocks. Finally, from 13 to 7 Ma the fossils have 87Sr/86Sr similar to those of Miocene seawater and their εNd values indicates fluctuating influence of Atlantic, and Indian Ocean or Paratethys sources of seawater entering the Mediterranean, driven by global sealevel changes and local tectonism. RÉSUMÉ DE LA THÈSE Les compositions en éléments traces et isotopiques de fossiles marins et de sédiments on été analysées à partir de nombreux dépôts marins dans la région circum Alpine dans le but de reconstruire les changements paléocéanographiques et paléoclimatiques liés aux changements du niveau marin, à l'évolution en bassins et à l'orogénie alpine. Au nord et à l'est des Alpes, une mer épicontinentale appelée Paratéthys s'est ouverte, alors que plus au sud la mer Méditerranée bordait au Miocène les Alpes naissantes. Le but de cette recherche est de se concentrer sur les sédiments et les fossiles provenant des couches du Miocènes de ces deux provinces marines. Les bassins de la Molasse Alpine du nord, de Vienne et Pannonien étaient situés au niveau de la Paratéthys Occidentale et Centrale. Les compositions isotopiques de l'oxygène de fossiles phosphatés bien préservés dans ces sédiments étayent la théorie d'un dépôt sous un climat subtropical à tempéré chaud avec des températures entre 14 et 28°C pendant le Miocène. Les valeurs δ18O des fossiles sont similaires à la tendance globale jusqu'à la fin du Badénien. Cependant les larges fluctuations en δ18O indiquent des effets locaux au niveau des sous bassins. En outre, deux dents de requin exceptionnelles présentent des valeurs extrêmement basses de δ18O. Ces données suggèrent que ces deux dents se sont formées alors que les requins fréquentaient un environnement d'eau douce avec de faibles valeurs de 18O. Le calcul de la composition isotopique de l'oxygène de cette eau douce permet d'obtenir une estimation de la paléoélévatian moyenne des Alpes du Miocène (~2300m). La tendance 87Sr/86Sr pour ces échantillons concorde approximativement avec un environnement d'océan ouvert au cours du Miocène. Toutefois un nombre d'échantillons dévie des compositions d'océan ouvert typiques, avec des rapports élevés suggérant des modifications de l'eau de mer par des sources locales et terrestres. Les effets locaux sont aussi reflétés au niveau des valeurs en εNd des fossiles paratéthysiens. Ceci est cohérent avec un apport d'anciennes roches cristallines et de sédiments mésozoïques, tandis que d'autres échantillons avec des valeurs hautes de εNd indiquent une influence d'un volcanisme néogène dans le budget marin. En excluant les échantillons dont les compositions isotopiques confirment une influence locale, une valeur moyenne de εNd de 7.9 t 0.5 peut être déduite pour l'eau de la Parathétys. Cette valeur est semblable à la valeur correspondant à l'Océan Indien durant le Miocène, confirmant un rôle dominant de cet océan dans la Paratéthys. Au niveau de la Méditerranée, les compositions en isotopes stables du Carbone et de l'Oxygène de foraminifères planctoniques et benthique de la région Umbria-Marche présentent un offset typique à leurs habitats. De plus les changements dans leurs compositions suivent les changements globaux, suggérant ainsi que les conditions climatiques régionales et le cycle du carbone étaient contrôlés par des phénomènes globaux. La composition en isotopes radiogéniques d'assemblages fossiles permet une reconnaissance sur trois périodes distinctes. De 25 à 19 millions d'années (Ma), des valeurs élevées de εNd et un faible rapport 87Sr/86Sr dans les sédiments soutiennent l'idée d'une activité tectonique et volcanique intense, liée à l'ouverture de la Méditerranée occidentale. Entre 19 et 13 Ma, la Méditerranée montre des valeurs de εNd qui sont largement contrôlées par une incursion d'eau provenant de l'Océan Indien. En effet, aux alentours de 15,2 Ma, des pics dans l'enregistrement des valeurs de εNd, coïncidant avec des événements volcaniques et de brèves diminutions du niveau marin. Enfin, de 13 à 7 Ma, les fossiles ont des rapports ß7Sr/8fiSr similaires à ceux de l'eau de mer au Miocène. Leurs valeurs de εNd indiquent une influence changeante de l'océan Atlantique, et de l'océan Indien ou des sources d'eau de merde la Parathétys qui entrent dans les bassins méditerranéens. Ce changement est guidé par des modifications globales du niveau marin et par la tectonique locale. RÉSUMÉ DE LA THÈSE (POUR LE GRAND PUBLIC) Les analyses des compositions en éléments traces et isotopiques des fossiles marins sont un outil très utile pour reconstruire les conditions océaniques et climatiques anciennes. Ce travail de thèse se concentre sur les sédiments déposés dans un environnement marin proches des Alpes au cours du Miocène, entre 23 et 7 millions d'années (Ma). Cette période est caractérisée par une tectonique alpine active, ainsi que par des changements climatiques et océanographiques globaux importants. Dans le but de tracer ces changements, les compositions isotopiques du Strontium, du Néodyme, de l'Oxygène et du Carbone ont été analysées dans des fossiles bien préservés ainsi que les sédiments contemporains. Les échantillons proviennent de deux provinces océaniques distinctes, la première est la Mer Méditerranée, et l'autre est une mer épicontinentale appelée Parathétys, qui existait au nord et à l'est des Alpes durant le Miocène. Au niveau de la Parathétys Occidentale et Orientale, les compositions isotopiques d'oxygène de dents de requins confirment un dépôt sous un climat subtropical à tempéré chaud avec des températures d'eau entre 14 et 28°C au Miocène. En outre, deux dents de requins exceptionnelles ont enregistré des compositions isotopiques d'oxygène extrêmement basses. Cela suggère que ces deux dents se sont formées alors que les requins entraient dans un système d'eau douce. Le calcul de la composition isotopique de l'oxygène de cette eau douce permet d'obtenir une estimation de la paléoélévation des Alpes au Miocène qui est aussi élevée que celle d'aujourd'hui. La tendance isotopique du Strontium pour ces échantillons concorde approximativement avec un environnement d'océan ouvert. Cependant un certain nombre d'échantillons indique des modifications de l'eau de mer par des sources terrestres locales. Les effets locaux sont aussi visibles au niveau des compositions isotopiques du Néodyme, qui sont en accord avec un apport provenant de roches cristallines anciennes et de sédiments du Mésozoïque, alors que d'autres échantillons indiquent une influence volcanique néogène dans le budget marin. A l'exclusion des échantillons dont les compositions correspondent à une influence locale, les compositions isotopiques du Néodyme de la Parathétys sont très similaires aux valeurs de l'Océan Indien, montrant ainsi un rôle important des masses d'eau IndoPacifiques dans cette région. Au niveau de la Méditerranée, les compositions en isotopes stables du Carbone et de l'Oxygène de foraminifères planctoniques et benthique de la région Umbria-Marche présentent un offset typique à leurs habitats. De plus, les changements dans leurs compositions suivent les changements globaux, suggérant ainsi que les conditions climatiques régionales et le cycle du carbone étaient contrôlés par des phénomènes globaux. La composition en isotopes radiogéniques d'assemblages fossiles permet une reconnaissance sur trois périodes distinctes. De 25 à 19 Ma, des rapport isotopiques élevés pour le Néodyme et faibles pour le Strontium dans les sédiments et les fossiles soutiennent l'idée d'une activité tectonique et volcanique intense, liée à l'ouverture de la Méditerranée occidentale. Entre 19 et 13 Ma, la Méditerranée présente des rapports isotopiques du Néodyme qui sont largement contrôlés par une incursion d'eau provenant de l'Océan Indien. En effet, aux alentours de 15,2 Ma, des pics dans l'enregistrement des valeurs des isotopes du Néodyme coïncident avec des événements volcaniques et de brèves diminutions du niveau marin. Finalement, de 13 à 7 Ma, les fossiles ont des rapports isotope Strontium similaires à ceux de l'eau de mer au Miocène. Les rapports isotopiques du Néodyme indiquent une influence changeante de l'océan Atlantique, et de l'océan Indien ou des sources d'eau de mer de la Parathétys qui entrent dans les bassins méditerranéens. Ce changement est guidé par des modifications globales du niveau marin et par la tectonique locale.

Late Oligocene Larger Foraminifera from Nosara (Nicoya Península, Costa Rica) and Windward (Carriacou, Lesser Antilles), calibrated by 87Sr/86Sr isotope stratigraphy.

ABSTRACT: The Late Oligocene first occurrence of Miogypsina gunteri Cole and Miogypsina tani Drooger is verified in the light of larger foraminiferal assemblages from Nosara (Nicoya Peninsula, Costa Rica) and Windward (Carriacou, Grenada, Lesser Antilles). At Windward, they co-occur with planktonic foraminifera and nannofossils studied by earlier workers. 87Sr/86Sr isotope ratios were measured in calcite of larger foraminifera at both sites to determine independent absolute ages of the two outcrops. Late Oligocene shallow water formations unconformably overlie Paleocene-Eocene distal turbidites and siliceous shales in the outcrops in Costa Rica. The shallow-water lithostratigraphy includes near shore volcanic sandstones that alternate with sandy bioclastic limestones. The latter have yielded rich assemblages of larger foraminifera that have been studied in oriented sections, SEM for split material and polished rock thin sections for transmitted light and cathodoluminescence (CL) observation. The association of larger foraminifera includes Heterostegina antillea Cushman, Miogypsina tani Drooger, Miogypsina gunteri Cole, Miogypsina c.f (Miolepidocyclina) panamensis (Cushman), Miogypsina sp., Lepidocyclina (nephrolepidina) vaughani Cushman, Lepidocyclina yurnagurensis Cushman, Lepidocyclina undosa Cushman. At Windward, scattered outcrops of the Belvedere Formation expose mass flow deposits rich in larger foraminifera associated with an early late Oligocene (NP24) planktonic foraminifa assemblage. Planktonic foraminifera and nanno-fossils recovered in rocks slightly downsection indicate an upper Middle Oligocene age. Larger foraminifera species collected just north of Windward include Lepidocyclina undosa Cushman and Miogypsina gunteri Cole. The 87Sr/86Sr ratio was measured in 11 specimens of megalosphaeric Lepidocyclina spp., mechanically extracted from 2 rock samples collected at Punta Peladas (Costa Rica) Ratios range from 0.709088 to 0.708196, which correspond to a model age of 27.4 to 24.94 Ma. Very similar ratios, ranging from 0.708150 to 0.708167 were obtained from Windward Village (Carriacou). All measured 87Sr/86Sr ratios fall within a Chattian (Late Oligocene) age. Nannofossils, planktonic foraminifera and identical 87Sr/86Sr ratios from Punta Peladas and Windward clearly indicate a Chattian (Upper Oligocene) first occurrence of Miogypsina gunteri and Miogypsina tani and confirm this age range for the other larger foraminifera cited above. The first occurrence of Miogypsina gunteri in the lower Athe upper Aquitanian as proposed by European workers cannot be confirmed.

Leadership Development Opportunities, January 2010

This Guide summarizes some of the many opportunities and experiences available to Iowa youth to enhance their leadership potential and to exercise their leadership abilities. This information was compiled at the request of the Youth Planning Committee for the Governor’s Youth Leadership and Mentoring Conference in 1999 and has continued through the Iowa Collaboration for Youth Development. Although not an exhaustive listing, the Guide provides information on many of the state and national leadership development opportunities for middle and high school youth throughout Iowa. Contact information for each program is provided for those wanting to learn more about the opportunities summarized in the Guide. Recommendations for program additions for future publication of this Guide are welcome.

Alkaline phosphatase activity as a tool for assessing nutritional conditions in the seagrass Posidonia oceanica.(L.) Delile

The effects of experimental phosphorus enrichments on alkaline phosphatase activity (APA) of the seagrass Posidonia oceanica (L.) Delile were tested. Short-term additions (as phosphate, 12 hours, in the laboratory) decreased APA by 18-2896, depending on the plant part considered (roots, young leaves or old leaves). The values of APA after this treatment were well correlated with interna1 phosphorus pools (as P concentration in plant tissues). Long-term additions (as phosphate, added to the sediment, 1 month in situ) decreased APA by 40-75%, also depending on the plant part. We conclude that alkaline phosphatase activity is a good indicator of P deficiency in this seagrass. We used this indicator to assess the P-nutritional status in a series of meadows in the NW Mediterranean, finding a high geographical variability, but correlations between APA and basic features of the meadows (carbonate content of the sediment, organic content of the sediment, shoot density, etc.) were not significant. Consequently, phosphorus deficiency does not seem to be directly related to these descriptors.

Effects of riparian vegetation removal on nutrient retention in a Mediterranean stream

We examined the effects of riparian vegetation removal on algal dynamics and stream nutrient retention efficiency by comparing NH4-N and PO4-P uptake lengths from a logged and an unlogged reach in Riera Major, a forested Mediterranean stream in northeastern Spain. From June to September 1995, we executed 6 short-term additions of N (as NH4Cl) and P (as Na2HPO4) in a 200-m section to measure nutrient uptake lengths. The study site included 2 clearly differentiated reaches in terms of canopy cover by riparian trees: the first 100 m were completely logged (i.e., the logged reach) and the remaining 100 m were left intact (i.e., the shaded reach). Trees were removed from the banks of the logged reach in the winter previous to our sampling. In the shaded reach, riparian vegetation was dominated by alders (Alnus glutinosa). The study was conducted during summer and fall months when differences in light availability between the 2 reaches were greatest because of forest canopy conditions. Algal biomass and % of stream surface covered by algae were higher in the logged than in the shaded reach, indicating that logging had a stimulatory effect on algae in the stream. Overall, nutrient retention efficiency was higher (i.e., shorter uptake lengths) in the logged than in the shaded reach, especially for PO4-P. Despite a greater increase in PO4-P retention efficiency relative to that of NH4-N following logging, retention efficiency for NH4-N was higher than for PO4-P in both study reaches. The PO4-P mass-transfer coefficient was correlated with primary production in both study reaches, indicating that algal activity plays an important role in controlling PO4-P dynamics in this stream. In contrast, the NH4-N mass-transfer coefficient showed a positive relation-ship only with % of algal coverage in the logged reach, and was not correlated with any algal-related parameter in the shaded reach. The lack of correlation with algal production suggests that mechanisms other than algal activity (i.e., microbial heterotrophic processes or abiotic mechanisms) may also influence NH4-N retention in this stream. Overall, this study shows that logging disturbances in small shaded streams may alter in-stream ecological features that lead to changes in stream nutrient retention efficiency. Moreover, it emphasizes that alteration of the tight linkage between the stream channel and the adjacent riparian zone may directly and indirectly impact biogeochemical processes with implications for stream ecosystem functioning.

Addicions a la flora vascular del Parc Natural del Cadí-Moixeró i de les serres veïnes (Prepirineus Orientals Ibèrics)

Additions to the vascular flora of the Cadí-Moixeró Natural Park and neighbouring Pre-Pyrenean areas (eastern Iberian Pyrenees) We present about fifty contributions to the catalogue of the vascular flora of the mentioned area, published in 2003. Among the taxa reported, 21 correspond to novelties found in our own field observations or in the literature. We highlight the first records for the Eastern Iberian Pre-Pyrenees of Meconopsis cambrica (L.) Vig. and Omalotheca hoppeana (Koch) Schulz Bip. and F.W. Schulz. Other data refer to rare taxa already included in the catalogue, such as Gagea lutea (L.) Ker Gawl., G. reverchonii Degen, Lappula deflexa (Wahlenb.) Garcke and Minuartia villarii (Balb.) Wilczek and Chenevard.

Evaluation of Carbonate Aggregate Using X-Ray Analysis, HR-266, 1989

Iowa has more than 13,000 miles of portland cement concrete (PCC) pavement. Some pavements have performed well for over 50 years, while others have been removed or overlaid due to the premature deterioration of joints and cracks. Some of the premature deterioration is classical D-cracking, which is attributed to a critically saturated aggregate pore system (freeze-thaw damage). However, some of the premature deterioration is related to adverse chemical reactivity involving carbonate coarse aggregate. The objective of this paper is to demonstrate the value of a chemical analysis of carbonate aggregate using X-ray equipment to identify good or poor quality. At least 1.5% dolomite is necessary in a carbonate aggregate to produce a discernible dolomite peak. The shift of the maximum-intensity X-ray diffraction dolomite d-spacing can be used to predict poor performance of a carbonate aggregate in PCC. A limestone aggregate with a low percentage of strontium (less than 0.013) and phosphorus (less than 0.010) would be expected to give good performance in PCC pavement. Poor performance in PCC pavement is expected from limestone aggregates with higher percentages (above 0.05) of strontium.

Long-term and long range migration of radioisotopes in terrestrial systems : mechanisms of radioisotopes (Cs, Sr, Pu, Am) mobilization in soils

Summary Artificial radionuclides were released in the environment during the atmospheric nuclear weapon tests and after accidental events involving nuclear industries. As a primary receptor of the deposition, the soil is a very sensitive compartment and understanding the interaction and migration of radionuclides within soils allows the development of scenario for the contamination risk of the population and of the environment. Most available field studies on radionuclides in soils only concern one or two isotopes, mostly 137Cs, and few physico-chemical soil parameters. The purpose of this study was a broader understanding of the radioecology of an Alpine valley. In a first part, we aimed to describe the depth distribution of 137Cs, 90Sr, 239+240Pu, and 241Am within different alpine soils and to identify some stable elements as indicators for accumulating layers. In the central part of the study, the goal was to investigate the repartition of ^Sr and 239Pu between the truly dissolved fraction and the colloidal fraction of the soil solutions and to identify the nature of colloids involved in the adsorption of ^Sr and 239Pu. These results were integrated in an "advection- sorption" transport model seeking to explain the migration of 239Pu and 90Sr within the soils and to assess the importance of colloidal transport for these two isotopes. A further aspect studied was the role of the competition between the radioisotopes (137Cs and 90Sr) and their stable chemical analogues (K and Ca) with respect to plant uptake by different plant species. The results on the depth distribution within the soils showed that 137Cs was mostly retained in the topsoil, to the exception of an organic-rich soil (Histosol 2) receiving important surface runoff, where migration down to a depth of 30 cm was observed. 137Cs depth distribution within the soils was similar to unsupported 210Pb depth distribution. The plant uptake of 137Cs clearly depended on the concentration of exchangeable potassium in the soils. Moreover, we showed that the 137Cs uptake by certain species of the taxonomic orders Poales and Rosales was more sensitive to the increase in exchangeable Κ compared to other orders. Strontium-90 was much more mobile in the soils than 137Cs and depth migration and accumulation in specific AI- and Fe-rich layers were found down to 30 cm. Copper and Ni showed accumulations in these same layers, indicating their potential to be used as indicators for the migration of ^Sr within the soils. In addition, we observed a 90Sr activity peak in the topsoil that can be attributable to recycling of 90Sr by plant uptake. We demonstrated for the first time that a part of 90Sr (at least 40%) was associated with the colloids in organic-rich soil solutions. Therefore, we predict a significant effect of the colloidal migration of ^Sr in organic-rich soil solutions. The plant uptake results for 90Sr indicated a phylogenetic effect between Non-Eudicot and Eudicots: the order Poales concentrating much less 90Sr than Eudicots do. Moreover, we were able to demonstrate that the sensitivity of the 90Sr uptake by 5 different Alpine plant species to the amount of exchangeable Ca was species-independent. Plutonium and 241Am accumulated in the second layer of all soils and only a slight migration deeper than 20 cm was observed. Plutonium and 241Am showed a similar depth distribution in the soils. The model results suggested that the present day migration of 239Pu was very slow and that the uptake by plants was negligible. 239Pu activities between 0.01 to 0.08 mBq/L were measured in the bulk soil solutions. Migration of 239Pu with the soil solution is dominated by colloidal transport. We reported strong evidences that humic substances were responsible of the sorption of 239Pu to the colloidal fraction of the soil solutions. This was reflected by the strong correlation between 239Pu concentrations and the content of (colloidal) organic matter in the soil solution. Résumé Certains radioéléments artificiels ont été disséminés dans l'environnement suite aux essais atmosphériques de bombes nucléaires et suite à des accidents impliquant les industries nucléaires. En tant que récepteur primaire de la déposition, le sol est un compartiment sensible et des connaissances sur les interactions et la migration des radioéléments dans le sol permettent de développer des modèles pour estimer la contamination de la population et de l'environnement. Actuellement, la plupart des études de terrain sur ce sujet concernent uniquement un ou deux radioéléments, surtout le 137Cs et peu d'études intègrent les paramètres du sol pour expliquer la migration des radioéléments. Le but général de cette étude était une compréhension étendue de la radio-écologie d'une vallée alpine. Notre premier objectif était de décrire la distribution en profondeur de 137Cs, ^Sr, 239+240pu et 241Am dans différents sols alpins en relation avec des éléments stables du sol, dans le but d'identifier des éléments stables qui pourraient servir d'indicateurs pour des horizons accumulateurs. L'objectif de la deuxième partie, qui était la partie centrale de l'étude, était d'estimer le pourcentage d'activité sous forme colloïdale du 239Pu et du 90Sr dans les solutions des sols. De plus nous avons déterminé la nature des colloïdes impliqués dans la fixation du ^Sr et 239Pu. Nous avons ensuite intégré ces résultats dans un modèle de transport développé dans le but de décrire la migration du 239Pu et 90Sr dans le sol. Finalement, nous avons étudié l'absorption de 137Cs et 90Sr par les plantes en fonction de l'espèce et de la compétition avec leur élément analogue stable (K et Ca). Les résultats sur la migration en profondeur du 137Cs ont montré que ce radioélément était généralement retenu en surface, à l'exception d'un sol riche en matière organique dans lequel nous avons observé une nette migration en profondeur. Dans tous les sols, la distribution en profondeur du 137Cs était corrélée avec la distribution du 210Pb. L'absorption du 137Cs par les plantes, était dépendante de la concentration en Κ échangeable dans le sol, le potassium étant un compétiteur. De plus, nous avons observé que les espèces ne réagissaient pas de la même manière aux variations de la concentration de Κ échangeable. En effet, les espèces appartenant aux ordres des Poales et des Rosales étaient plus sensibles aux variations de potassium échangeable dans le sol. Dans tous les sols Le 90Sr était beaucoup plus mobile que le 137Cs. En effet, nous avons observé des accumulations de 90Sr dans des horizons riches en Fe et Al jusqu'à 30 cm de profondeur. De plus, le Cu et le Ni montraient des accumulations dans les mêmes horizons que le 90Sr, indiquant qu'il pourrait être possible d'utiliser ces deux éléments comme analogues pour la migration du 90Sr. D'après le modèle développé, le pic de 90Sr dans les premiers centimètres du sol peut être attribué à du recyclage par les plantes. Le 90Sr en solution était principalement sous forme dissoute dans des solutions de sols peu organique (entre 60 et 100% de 90Sr dissous). Par contre, dans des solutions organiques, un important pourcentage de 90Sr (plus de 40%) était associé aux colloïdes. La migration colloïdale du 90Sr peut donc être significative dans des solutions organiques. Comme pour le 137Cs, l'absorption du 90Sr par les plantes dépendait de la concentration de son analogue chimique dans la fraction échangeable du sol. Par contre, les espèces de plantes étudiées avaient la même sensibilité aux variations de la concentration du calcium échangeable. Le plutonium et l'américium étaient accumulés dans le deuxième horizon du sol et nous avons observé seulement une faible migration plus profondément que 20 cm. Selon le modèle, la migration actuelle du plutonium est très lente et l'absorption par les plantes semble négligeable. Nous avons mesuré entre 0.01 et 0.08 mBq/L de 239Pu dans les solutions de sol brutes. La migration du plutonium par la solution du sol est due principalement aux colloïdes, probablement de nature humique. Résumé grand public Dans les années 1950 à 1960, l'environnement a été contaminé par des éléments radioactifs (radioéléments) artificiels provenant des essais des armes atomiques et de l'industrie nucléaire. En effet, durant ces années, les premiers essais de bombes atomiques se faisaient dans l'atmosphère, libérant de grandes quantités d'éléments radioactifs. De plus certains accidents impliquant l'industrie nucléaire civile ont contribué à la dissémination d'éléments radioactifs dans l'environnement. Ce fut par exemple le cas de l'accident de la centrale atomique de Tchernobyl en 1986 qui a causé une importante contamination d'une grande partie de l'Europe par le 137Cs. Lorsqu'ils sont libérés dans l'atmosphère, les radioéléments sont dispersés et transportés par les courants atmosphériques, puis peuvent être déposés dans l'environnement, principalement par les précipitations. Une fois déposés sur le sol, les radioéléments vont interagir avec les composants du sol et migrer plus ou moins vite. La connaissance des interactions des éléments radioactifs avec le sol est donc importante pour prédire les risques de contamination de l'environnement et de l'homme. Le but général de ce travail était d'évaluer la migration de différents éléments radioactifs (césium-137, strontium-90, plutonium et américium-241) à travers le sol. Nous avons choisi un site d'étude en milieu alpin (Val Piora, Tessin, Suisse), contaminé en radioéléments principalement par les retombées de l'accident de Tchernobyl et des essais atmosphériques de bombes atomiques. Dans un premier temps, nous avons caractérisé la distribution en profondeur des éléments radioactifs dans le sol et l'avons comparée à divers éléments stables. Cette comparaison nous a permit de remarquer que le cuivre et le nickel s'accumulaient dans les mêmes horizons du sol que le strontium-90 et pourraient donc être utilisés comme analogue pour la migration du strontium-90 dans les sols. Dans la plupart des sols étudiés, la migration du césium-137, du plutonium et de l'américium-241 était lente et ces radioéléments étaient donc accumulés dans les premiers centimètres du sol. Par contre, le strontium-90 a migré beaucoup plus rapidement que les autres radioéléments si bien qu'on observe des accumulations de strontium-90 à plus de 30 cm de profondeur. Les radioéléments migrent dans la solution du sol soit sous forme dissoute, soit sous forme colloïdale, c'est-à-dire associés à des particules de diamètre < Ιμηι. Cette association avec des colloïdes permet à des radioéléments peu solubles, comme le plutonium, de migrer plus rapidement qu'attendu. Nous avons voulu savoir quelle était la part de strontium-90 et plutonium associés à des colloïdes dans la solution du sol. Les résultats ont montré que le plutonium en solution était principalement associé à des colloïdes de type organique. Quant au strontium-90, ce dernier était en partie associé à des colloïdes dans des solutions de sol riches en matière organique, par contre, il était principalement sous forme dissoute dans les solutions de sol peu organiques. L'absorption de radioéléments par les plantes représente une voie importante pour le transfert vers la chaîne alimentaire, par conséquent pour la contamination de l'homme. Nous avons donc étudié le transfert du césium-137 et du strontium-90 de plusieurs sols vers différentes espèces de plantes. Les résultats ont montré que l'absorption des radioéléments par les plantes était liée à la concentration de leur analogue chimique (calcium pour le strontium-90 et potassium pour le césium- 137) dans la fraction échangeable du sol. De plus certaines espèces de plantes accumulent significativement moins de strontium-90.

Atmospheric deposition and migration of artificial radionuclides in Alpine soils (Val Piora, Switzerland) compared to the distribution of selected major and trace elements.

Artificial radionuclides ((137)Cs, (90)Sr, Pu, and (241)Am) are present in soils because of Nuclear Weapon Tests and accidents in nuclear facilities. Their distribution in soil depth varies according to soil characteristics, their own chemical properties, and their deposition history. For this project, we studied the atmospheric deposition of (137)Cs, (90)Sr, Pu, (241)Am, (210)Pb, and stable Pb. We compared the distribution of these elements in soil profiles from different soil types from an alpine Valley (Val Piora, Switzerland) with the distribution of selected major and trace elements in the same soils. Our goals were to explain the distribution of the radioisotopes as a function of soil parameters and to identify stable elements with analogous behaviors. We found that Pu and (241)Am are relatively immobile and accumulate in the topsoil. In all soils, (90)Sr is more mobile and shows some accumulations at depth into Fe-Al rich horizons. This behavior is also observed for Cu and Zn, indicating that these elements may be used as chemical analogues for the migration of (90)Sr into the soil.

Fluid migration through thrust faults in the Helvetic nappes (Western Swiss Alps)

The delta(18)O, delta(13)C and Sr-87/Sr-86 values of calcite and organic matter were measured for carbonate mylonites from numerous thrusts in the Helvetic Alps. Carbonate mylonites in most of the thrusts retain essentially unaltered protolith delta(18)O and delta(13)C values, consistent with there having been little to no advection of isotopically distinct fluid through these faults. Only carbonate mylonites from the basal thrusts of the largest nappes have delta(18)O and/or delta(13)C values that differ from those of their protoliths. The zone of isotopic alteration/exchange is confined to c. 10 to 20 meters of these fault contacts. We propose the fluids that migrated through these faults contained variable amounts of organically derived carbon and radiogenic strontium, and were probably derived from dewatering of the sedimentary rocks and prograde metamorphic reactions in the nappes' root zones. Apart from the basal thrusts of the largest nappes that behaved as narrow, laterally extensive conduits for fluids, there is little isotopic evidence that large quantities of fluids passed through most of the carbonate-hosted thrusts in the Helvetic Alps.